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Sample records for intracranial pressure measurement

  1. Micro packaged MEMS pressure sensor for intracranial pressure measurement

    Science.gov (United States)

    Xiong, Liu; Yan, Yao; Jiahao, Ma; Yanhang, Zhang; Qian, Wang; Zhaohua, Zhang; Tianling, Ren

    2015-06-01

    This paper presents a micro packaged MEMS pressure sensor for intracranial pressure measurement which belongs to BioMEMS. It can be used in lumbar puncture surgery to measure intracranial pressure. Miniaturization is key for lumbar puncture surgery because the sensor must be small enough to allow it be placed in the reagent chamber of the lumbar puncture needle. The size of the sensor is decided by the size of the sensor chip and package. Our sensor chip is based on silicon piezoresistive effect and the size is 400 × 400 μm2. It is much smaller than the reported polymer intracranial pressure sensors such as liquid crystal polymer sensors. In terms of package, the traditional dual in-line package obviously could not match the size need, the minimal size of recently reported MEMS-based intracranial pressure sensors after packaging is 10 × 10 mm2. In this work, we are the first to introduce a quad flat no-lead package as the package form of piezoresistive intracranial pressure sensors, the whole size of the sensor is minimized to only 3 × 3 mm2. Considering the liquid measurement environment, the sensor is gummed and waterproof performance is tested; the sensitivity of the sensor is 0.9 × 10-2 mV/kPa. Project supported by the National Natural Science Foundation of China (Nos. 61025021, 61434001), and the ‘Thousands Talents’ Program for Pioneer Researchers and Its Innovation Team, China.

  2. Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound

    Science.gov (United States)

    Hargens, A. R.

    1998-01-01

    Prevention of secondary brain injuries following head can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop (PPLL) devise, which was developed and patented, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year one studies involved instrument improvements and measurement of altered intracranial distance with altered ICP in fresh cadavera. Our software was improved to facilitate future studies of normal subjects and trauma patients. Our bench studies proved that PPLL output correlated highly with changes in path length across a model cranium. Cadaveric studies demonstrated excellent compact, noninvasive devise for monitoring changes in intracranial distance may aid in the early detection of elevated ICP, decreasing risk of secondary brain injury and infection, and returning head-injured patients to duty.

  3. Measuring elevated intracranial pressure through noninvasive methods

    DEFF Research Database (Denmark)

    Kristiansson, Helena; Nissborg, Emelie; Bartek, Jiri;

    2013-01-01

    . This article is a review of the current literature on noninvasive methods for measuring and evaluating elevated ICP. The main focus is on studies that compare noninvasively measured ICP with invasively measured ICP. The aim is to provide an overview of the current state of the most common noninvasive...... is associated with certain risks. Intraparenchymal ICP monitoring methods are considered to be a safer alternative but can, in certain conditions, be imprecise due to zero drift and still require an invasive procedure. An accurate noninvasive method to measure elevated ICP would therefore be desirable...

  4. Non-Invasive Measurement of Pulsatile Intracranial Pressures Using Ultrasound

    Science.gov (United States)

    Ueno, Toshiaki; Ballard, Richard E.; Shuer, Lawrence M.; Cantrell, John H.; Cantrell, John H.; Hargens, Alan R.

    1997-01-01

    Early detection of elevated intracranial pressure (ICP) will aid clinical decision-making for head trauma, brain tumor and other cerebrovascular diseases. Conventional methods, however, require surgical procedures which take time and are accompanied by increased risk of infection. Accordingly we have developed and refined a new ultrasound device to measure skull movements which are known to occur in conjunction with altered ICP. The principle of this device is based upon pulse phase locked loop (PPLL), which enables us to detect changes in distance on the order of microns between an ultrasound transducer on one side of the skull and the opposite inner surface of the cranium. The present study was designed to verify this measurement technique in cadavera. Transcranial distance was increased in steps of 10 mmHg from zero to 50 mmHg by saline infusion into the lateral ventricle of two cadavera. In separate experiments, pulsations of ICP with the amplitudes of zero to 2 mmHg were generated by rhythmic injections of saline using a syringe. When the ICP was stepwise increased from zero to 50 mmHg, transcranial distance increased in proportion with the ICP increase (y=12 x - 76, r=0.938), where y is changes in transcranial distance in microns and x is ICP in mmHg. In the data recorded while ICP pulsations were generated, fast Fourier transform analysis demonstrated that cranial pulsations were clearly associated with ICP pulsations. The results indicate that changes in transcranial distance is linearly correlated with those in ICP, and also that the PPLL device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. By analyzing the magnitude of cranial pulsations, we may be able to estimate the pressure-volume index in the cranium. As a result, estimates of intracranial compliance may be possible by using the PPLL device. Further studies are necessary in normal subjects and patients.

  5. Non-Invasive Measurement of Pulsatile Intracranial Pressures Using Ultrasound

    Science.gov (United States)

    Ueno, Toshiaki; Ballard, Richard E.; Shuer, Lawrence M.; Cantrell, John H.; Cantrell, John H.; Hargens, Alan R.

    1997-01-01

    Early detection of elevated intracranial pressure (ICP) will aid clinical decision-making for head trauma, brain tumor and other cerebrovascular diseases. Conventional methods, however, require surgical procedures which take time and are accompanied by increased risk of infection. Accordingly we have developed and refined a new ultrasound device to measure skull movements which are known to occur in conjunction with altered ICP. The principle of this device is based upon pulse phase locked loop (PPLL), which enables us to detect changes in distance on the order of microns between an ultrasound transducer on one side of the skull and the opposite inner surface of the cranium. The present study was designed to verify this measurement technique in cadavera. Transcranial distance was increased in steps of 10 mmHg from zero to 50 mmHg by saline infusion into the lateral ventricle of two cadavera. In separate experiments, pulsations of ICP with the amplitudes of zero to 2 mmHg were generated by rhythmic injections of saline using a syringe. When the ICP was stepwise increased from zero to 50 mmHg, transcranial distance increased in proportion with the ICP increase (y=12 x - 76, r=0.938), where y is changes in transcranial distance in microns and x is ICP in mmHg. In the data recorded while ICP pulsations were generated, fast Fourier transform analysis demonstrated that cranial pulsations were clearly associated with ICP pulsations. The results indicate that changes in transcranial distance is linearly correlated with those in ICP, and also that the PPLL device has sufficient sensitivity to detect transcranial pulsations which occur in association with the cardiac cycle. By analyzing the magnitude of cranial pulsations, we may be able to estimate the pressure-volume index in the cranium. As a result, estimates of intracranial compliance may be possible by using the PPLL device. Further studies are necessary in normal subjects and patients.

  6. Relationship between intracranial pressure and phase contrast cine MRI derived measures of intracranial pulsations in idiopathic normal pressure hydrocephalus.

    Science.gov (United States)

    Jaeger, Matthias; Khoo, Angela K; Conforti, David A; Cuganesan, Ramesh

    2016-11-01

    Phase contrast cine MRI with determination of pulsatile aqueductal cerebrospinal fluid (CSF) stroke volume and flow velocity has been suggested to assess intracranial pulsations in idiopathic normal pressure hydrocephalus (iNPH). We aimed to compare this non-invasive measure of pulsations to intracranial pressure (ICP) pulse wave amplitude from continuous ICP monitoring. We hypothesised that a significant correlation between these two markers of intracranial pulsations exists. Fifteen patients with suspected iNPH had continuous computerised ICP monitoring with calculation of mean ICP pulse wave amplitude (MWA) from time-domain analysis. MRI measured CSF aqueductal stroke volume and peak flow velocity. Mean MWA was 5.4mmHg (range 2.3-12.4mmHg). Mean CSF stroke volume and peak flow velocity were 65μl (range 3-195μl) and 9.31cm/s (range 1.68-15.0cm/s), respectively. No significant correlation between the invasive and non-invasive measures of pulsations existed (Spearman r=-0.30 and r=-0.27, respectively; p>0.05). We observed marked intra-individual fluctuation of MWA during continuous ICP monitoring of an average of 6.0mmHg (range 2.8-12.2mmHg). The results suggest a complex interplay between measures of pulsations derived from snapshot MRI measurements and continuous computerised ICP measurements, as no significant relationship existed in our data. Further study is needed to better understand the temporal profile of CSF MRI flow studies, as substantial variation in MWA over the course of several hours of ICP monitoring is common, suggesting that these physiologic fluctuations might obscure MRI snapshot measures of intracranial pulsations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Intracranial pressure monitoring

    Science.gov (United States)

    ICP monitoring; CSF pressure monitoring ... There are 3 ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is the most accurate monitoring method. To insert an intraventricular catheter, a ...

  8. Noninvasive Intracranial Volume and Pressure Measurements Using Ultrasound (Head and Spinal)

    Science.gov (United States)

    Hargens, Alan R.

    1999-01-01

    Prevention of secondary brain injuries following head trauma can be accomplished most easily when intracranial pressure (ICP) is monitored. However, current measurement techniques are invasive and thus not practical in the combat environment. The Pulsed Phase Lock Loop device, which was developed and patented by consultants Drs. Yost and Cantrell, uses a unique, noninvasive ultrasonic phase comparison method to measure slight changes in cranial volume which occur with changes in ICP. Year two studies included whole body head-up and head-down tilting effects on intracranial compliance and pressure in six healthy volunteers.

  9. Increased intracranial pressure

    Science.gov (United States)

    ... patient's bedside in an emergency room or hospital. Primary care doctors may sometimes spot early symptoms of increased intracranial pressure such as headache, seizures, or other nervous system problems. An MRI ...

  10. INTRACRANIAL PRESSURE MONITORING

    Directory of Open Access Journals (Sweden)

    Retno Widiyanthi

    2013-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Intracranial pressure is total of pressure that is produced by brain, blood, and cerebrospinal fluid/CSF in the tight cranial space. As a respon to intracranial pressure increasing, compensation begin by movement of CSF from ventricle to cerebral subarachnoidal space, and increase the absorption of CSF. Increasing of ICP usually caused by increasing of brain volume (cerebral oedem, blood (intracranial bleeding, space occupying lesion, or CSF (hidrocephalus. Indication in ICP monitoring can be seen from : neurological criteria, abnormal CT-scan result when admission, normal CT-scan result, but had more two risk factors. According to the procedure that must be done, there are two methods in ICP monitoring: invasive ICP monitoring methodes and non-invasive measuring method. Increasing of ICP will decrease the compliance of brain, pulsation of artery more clearly, and the component of vein is lost. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  11. Intracranial Pressure Monitoring

    DEFF Research Database (Denmark)

    Raboel, P H; Bartek, J; Andresen, M;

    2012-01-01

    Monitoring of intracranial pressure (ICP) has been used for decades in the fields of neurosurgery and neurology. There are multiple techniques: invasive as well as noninvasive. This paper aims to provide an overview of the advantages and disadvantages of the most common and well-known methods as ......-invasive techniques are without the invasive methods' risk of complication, but fail to measure ICP accurately enough to be used as routine alternatives to invasive measurement. We conclude that invasive measurement is currently the only option for accurate measurement of ICP....... as well as assess whether noninvasive techniques (transcranial Doppler, tympanic membrane displacement, optic nerve sheath diameter, CT scan/MRI and fundoscopy) can be used as reliable alternatives to the invasive techniques (ventriculostomy and microtransducers). Ventriculostomy is considered the gold...

  12. Hypertensive response to raised intracranial pressure in infancy.

    OpenAIRE

    Kaiser, A M; Whitelaw, A G

    1988-01-01

    Mean arterial pressure and intracranial pressure were measured serially in six infants with intracranial hypertension (intracranial pressure greater than 20 mm Hg), and cerebral perfusion pressure was calculated from their difference. Overall, mean arterial pressure increased with rising intracranial pressure at a mean rate of 0.20 mm Hg/mm Hg. This caused a fall in cerebral perfusion pressure with increasing intracranial pressure at a mean rate of 0.80 mm Hg/mm Hg overall, although cerebral ...

  13. Measuring Blast-Related Intracranial Pressure Within the Human Head

    Science.gov (United States)

    2010-08-01

    of the data from the s ensor placed in the parietal lobe. However sensor breakage was lower than expected for a first setup: the expertise used to...connected to s ensor location in the IC pressur e profiles, as it c an be noted in all th e figures presented that had diagram s with same exposure and

  14. Monitoring of Intracranial Pressure During Intracranial Endoscopy

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    Rajeev Kumar

    2013-08-01

    Full Text Available Background: Intracranial endoscopy is a minimum invasive procedure, which reduces trauma to the brain, is cost-effective, and carries a shortened hospital stay with an improved postoperative outcome. Objective: To monitor intracranial pressure changes during intracranial endoscopy among children and adults under general anesthesia/sedation, and to compare the intracranial pressure changes between children and adults receiving general anesthesia and among adults receiving general anesthesia and sedation. Methods: The present cross-sectional study was conducted in one of the tertiary care hospitals of Lucknow. This was carried out in the department of neurosurgery from January 2008 to December 2008. Patients who were not fit for general anesthesia received local anesthesia under sedation. Patients participating in the study were divided into three groups. Intracranial pressure was recorded at specific intervals. Parametric data were subjected to statistical analysis using a student\\s t test. Result: A total of 70 patients were undergoing intracranial endoscopy under general anesthesia during the study period. In both groups A and B, intracranial pressure increases the maximum during inflation of the balloon. In group C, all the variations in ICP were found to be statistically significant. In the comparison of intracranial pressure changes between groups A and B, no significant difference was found. All correlations in the comparison of groups B and C were found to be statistically significant (p< 0.001. Conclusion: There is a need for continuous intraoperative monitoring of ICP intracranial endoscopy, because ICP increases in various stages of the procedure, which can be detrimental to the perfusion of the brain. [Arch Clin Exp Surg 2013; 2(4.000: 240-245

  15. Clinical comparison of tympanic membrane displacement with invasive intracranial pressure measurements.

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    Shimbles, S; Dodd, C; Banister, K; Mendelow, A D; Chambers, I R

    2005-12-01

    A non-invasive method of assessing intracranial pressure (ICP) would be of benefit to patients with abnormal cerebral pathology that could give rise to changes in ICP. In particular, it would assist the regular monitoring of hydrocephalus patients. This study evaluated a technique using tympanic membrane displacement (TMD) measurements, which has been reported to provide a reliable, non-invasive measure of ICP. A group of 135 hydrocephalus patients was studied, as well as 13 patients with benign intracranial hypertension and a control group of 77 volunteers. TMD measurements were carried out using the Marchbanks measurement system analyser and compared between the groups. In 36 patients, invasive measurements of ICP carried out at the same time were compared with the TMD values. A highly significant relationship was found between TMD and ICP but intersubject variability was high and the predictive value of the technique low. Taking the normal range of ICP to be 10-15 mmHg, the predictive limits of the regression are an order of magnitude wider than this and therefore Vm cannot be used as a surrogate for ICP. In conclusion, TMD measurements do not provide a reliable non-invasive measure of ICP in patients with shunted hydrocephalus.

  16. INTRACRANIAL PRESSURE MONITORING TECHNIQUE

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    Ida Bagus Adi Kayana

    2013-03-01

    Full Text Available Head injury is the most significant cause of increased morbidity and mortality. An estimated 1.4 million head injuries occur each year, with and more than 1.1 million come to the Emergency Unit. On each patient head injury, an increase in intracranial pressure (ICP related to poor outcomes and aggressive therapy to increased ICP can improve the outcomes. ICP monitoring is the most widely used because of the prevention and control of ICP as well as maintain the pressure increase perfusion of cerebral (Cerebral Perfusion Pressure/CPP is the basic purpose of handling head injury. There are two methods of monitoring ICP that is an invasive methods (directly and non-invasive techniques (indirectly. The method commonly used, namely intraventricular and intraparenkimal (microtransducer sensor because it is more accurate but keep attention to the existence of the risk of bleeding and infection resulting from installation. Monitoring of ICT can determine the actions that avoid further brain injury, which can be lethal and irreversibel.

  17. [Correction of intracranial pressure in patients with traumatic intracranial hemorrhages].

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    Virozub, I D; Chipko, S S; Chernovskiĭ, V I; Cherniaev, V A

    1986-01-01

    Therapeutical correction of intracranial pressure changes were conducted in 14 patients suffering from traumatic intracranial hematomas by endolumbar administration of physiological solution. The distinguishing feature of this method is the possibility of continuous control of the intracranial pressure level by means of long-term graphic recording of epidural pressure. This makes it possible to perform endolumbar administration of physiological solution in a dose which is determined by the initial level of epidural intracranial pressure. Therapeutic correction of intracranial pressure by endolumbar injection of physiological solution proved successful in the initial stages of dislocation of the brain and in stable intracranial hypotension.

  18. Noninvasive and quantitative intracranial pressure estimation using ultrasonographic measurement of optic nerve sheath diameter

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    Wang, Li-juan; Yao, Yan; Feng, Liang-shu; Wang, Yu-zhi; Zheng, Nan-nan; Feng, Jia-chun; Xing, Ying-qi

    2017-01-01

    We aimed to quantitatively assess intracranial pressure (ICP) using optic nerve sheath diameter (ONSD) measurements. We recruited 316 neurology patients in whom ultrasonographic ONSD was measured before lumbar puncture. They were randomly divided into a modeling and a test group at a ratio of 7:3. In the modeling group, we conducted univariate and multivariate analyses to assess associations between ICP and ONSD, age, sex, BMI, mean arterial blood pressure, diastolic blood pressure. We derived the mathematical function “Xing & Wang” from the modelling group to predict ICP and evaluated the function in the test group. In the modeling group, ICP was strongly correlated with ONSD (r = 0.758, p Watson value = 1.94). In the test group, a significant correlation was found between the observed and predicted ICP (r = 0.76, p < 0.001). Bland-Altman analysis yielded a mean difference between measurements of −0.07 ± 41.55 mmH2O. The intraclass correlation coefficient and its 95%CIs for noninvasive ICP assessments using our prediction model was 0.86 (0.79–0.90). Ultrasonographic ONSD measurements provide a potential noninvasive method to quantify ICP that can be conducted at the bedside. PMID:28169341

  19. Fast diffuse correlation spectroscopy (DCS) for non-invasive measurement of intracranial pressure (ICP) (Conference Presentation)

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    Farzam, Parisa; Sutin, Jason; Wu, Kuan-Cheng; Zimmermann, Bernhard B.; Tamborini, Davide; Dubb, Jay; Boas, David A.; Franceschini, Maria Angela

    2017-02-01

    Intracranial pressure (ICP) monitoring has a key role in the management of neurosurgical and neurological injuries. Currently, the standard clinical monitoring of ICP requires an invasive transducer into the parenchymal tissue or the brain ventricle, with possibility of complications such as hemorrhage and infection. A non-invasive method for measuring ICP, would be highly preferable, as it would allow clinicians to promptly monitor ICP during transport and allow for monitoring in a larger number of patients. We have introduced diffuse correlation spectroscopy (DCS) as a non-invasive ICP monitor by fast measurement of pulsatile cerebral blood flow (CBF). The method is similar to Transcranial Doppler ultrasound (TCD), which derives ICP from the amplitude of the pulsatile cerebral blood flow velocity, with respect to the amplitude of the pulsatile arterial blood pressure. We believe DCS measurement is superior indicator of ICP than TCD estimation because DCS directly measures blood flow, not blood flow velocity, and the small cortical vessels measured by DCS are more susceptible to transmural pressure changes than the large vessels. For fast DCS measurements to recover pulsatile CBF we have developed a custom high-power long-coherent laser and a strategy for delivering it to the tissue within ANSI standards. We have also developed a custom FPGA-based correlator board, which facilitates DCS data acquisitions at 50-100 Hz. We have tested the feasibility of measuring pulsatile CBF and deriving ICP in two challenging scenarios: humans and rats. SNR is low in human adults due to large optode distances. It is similarly low in rats because the fast heart rate in this setting requires a high repetition rate.

  20. [A method for the noninvasive measurement and recording of intracranial pressure via the open fontanelle of infants].

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    Brömme, W; Baum, W F; Hirsch, W; Schaps, P; Schobess, A

    1985-01-01

    Measurement and checking of the behaviour of the intracranial pressure (ICP) are of considerable clinical interest for the appraisal and treatment of primary or concomitant cerebral diseases. A non-invasive method of the measurement of the cerebral pressure is presented, which permits measurements and graphic recording according to the aplanation principle of the ICP via the open fontanelle. The pressure uptake of the instrument transformer is effected by a resistance strain gauge, measurement and recording by means of an equipment combination of VEB Messgerätewerk Zwönitz (GDR). Methodological and theoretical foundations are described and normal values of the fontanelle pressure of 80 newborns and babies are submitted.

  1. Amendment on the strain measurement of thin-walled human skull shell as intracranial pressure changes

    Institute of Scientific and Technical Information of China (English)

    Xianfang Yue; Li Wang; Feng Zhou

    2008-01-01

    The human skuU,composed of tabula externa,tabula interna,and a porous diploe sandwiched in between,is deformed with changing intracranial pressure (ICP).Because the human skull's thickness is only 6 mm,it is simplified as a thin-walled shell. The objective of this article is to analyze the strain of the thin-walled shell by the stress-strain calculation of a human skull with changing ICP.Under the same loading conditions,using finite element analysis (FEA),the strains of the human skull were calculated and the results were compared with the measurements of the simulative experiment in vitro.It is demonstrated that the strain of the thin-walled shell is totally measured by pasting the one-way strain foils on the exterior surface of the shell with suitable amendment for data.The amendment scope of the measured strain values of the thin-walled shell is from 13.04% to 22.22%.

  2. Assessment of changes in Intracranial Pressure (ICP after the implementation of therapeutic measures for Intracranial Hypertation (IH

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    Nikoletta Arapoglou

    2014-07-01

    Full Text Available The Traumatic Brain Injury (TBI constitutes the leading cause of death and permanent disability in all age groups and, by far, at ages 19-27 years. The morbidity and mortality remain high and depend on the neurological status of patients at admission, the treatment in the Intensive Care Unit (ICU, surgery and postoperative rehabilitation and recovery. The prevention and treatment factors that may maintain or exacerbate the IH is a very important and fundamental issue in neurological intensive therapy. Aim: The aim of the present systematic review was to investigate the effectiveness of various therapeutic measures for the treatment of intracranial hypertension. Material and Method: The methodology used was to review the Greek and international bibliographic databases (Iatrotek, Pubmed, Cinahl, Scopus,. The keywords used to search for the study was: "Hyperventilation", "therapeutic hypothermia", "hyperosmolar therapy", "corticosteroids", "traumatic brain injury" and were the last 15 years. Results: Hyperventilation, the hyperosmolar therapy, barbiturates, patient position, sedatives-neuromuscular blocking agents, therapeutic hypothermia, corticosteroids and some aggressive surgical methods (decompressive craniotomy and drainage of CSF make up the puzzle of modern intensive care patients with severe TBI. The cornerstone for the control of intracranial hypertension are the hyperosmolar therapy, therapeutic hypothermia and patient position (supine-neutral to 30o-45o inclination. With skepticism, seems to treat hyperventilation, sedatives-neuromuscular blocking agents, the barbiturate coma and surgical methods of treatment. This is due to the plurality of complications that causing. Last but not least, corticosteroids have been implicated as a measure which does nothing to help patients with increased ICP, contrary aggravates their condition. Conclusions: Direct surgical treatment of IH accompanied by better results in terms of mortality, morbidity

  3. System for Rapid, Precise Modulation of Intraocular Pressure, toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure.

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    Max A Stockslager

    Full Text Available Pathologic changes in intracranial pressure (ICP are commonly observed in a variety of medical conditions, including traumatic brain injury, stroke, brain tumors, and glaucoma. However, current ICP measurement techniques are invasive, requiring a lumbar puncture or surgical insertion of a cannula into the cerebrospinal fluid (CSF-filled ventricles of the brain. A potential alternative approach to ICP measurement leverages the unique anatomy of the central retinal vein, which is exposed to both intraocular pressure (IOP and ICP as it travels inside the eye and through the optic nerve; manipulating IOP while observing changes in the natural pulsations of the central retinal vein could potentially provide an accurate, indirect measure of ICP. As a step toward implementing this technique, we describe the design, fabrication, and characterization of a system that is capable of manipulating IOP in vivo with <0.1 mmHg resolution and settling times less than 2 seconds. In vitro tests were carried out to characterize system performance. Then, as a proof of concept, we used the system to manipulate IOP in tree shrews (Tupaia belangeri while video of the retinal vessels was recorded and the caliber of a selected vein was quantified. Modulating IOP using our system elicited a rapid change in the appearance of the retinal vein of interest: IOP was lowered from 10 to 3 mmHg, and retinal vein caliber sharply increased as IOP decreased from 7 to 5 mmHg. Another important feature of this technology is its capability to measure ocular compliance and outflow facility in vivo, as demonstrated in tree shrews. Collectively, these proof-of-concept demonstrations support the utility of this system to manipulate IOP for a variety of useful applications in ocular biomechanics, and provide a framework for further study of the mechanisms of retinal venous pulsation.

  4. A fluid-structure interaction model of the internal carotid and ophthalmic arteries for the noninvasive intracranial pressure measurement method.

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    Misiulis, Edgaras; Džiugys, Algis; Navakas, Robertas; Striūgas, Nerijus

    2017-03-22

    Accurate and clinically safe measurements of intracranial pressure (ICP) are crucial for secondary brain damage prevention. There are two methods of ICP measurement: invasive and noninvasive. Invasive methods are clinically unsafe; therefore, safer noninvasive methods are being developed. One of the noninvasive ICP measurement methods implements the balance principle, which assumes that if the velocity of blood flow in both ophthalmic artery segments - the intracranial (IOA) and extracranial (EOA) - is equal, then the acting ICP on the IOA and the external pressure (Pe) on the EOA are also equal. To investigate the assumption of the balance principle, a generalized computational model incorporating a fluid-structure interaction (FSI) module was created and used to simulate noninvasive ICP measurement by accounting for the time-dependent behavior of the elastic internal carotid (ICA) and ophthalmic (OA) arteries and their interaction with pulsatile blood flow. It was found that the extra balance pressure term, which incorporates the hydrodynamic pressure drop between measurement points, must be added into the balance equation, and the corrections on a difference between the velocity of blood flow in the IOA and EOA must be made, due to a difference in the blood flow rate.

  5. Comparison of ultrasonographic measurement of optic nerve sheath diameter (ONSD) versus direct measurement of intracranial pressure (ICP) in traumatic brain injury patients

    OpenAIRE

    2011-01-01

    Aim. To compare ultrasonographic measurement of optic nerve sheath diameter (ONSD) with direct measurement of intracranial pressure (ICP) and evaluate the correlation between them in traumatic brain injury patients. Patients and methods. Twenty traumatic brain injury patients were enrolled in the study. Patients had a median Glasgow Coma Scale (GCS) score of 5. All patients underwent noninvasive measurement of ICP by ultrasonographic measurement of ONSD and invasive ICP measurement using ...

  6. Elevated Intracranial Pressure Diagnosis with Emergency Department Bedside Ocular Ultrasound

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    D. Amin

    2015-01-01

    Full Text Available Bedside sonographic measurement of optic nerve sheath diameter can aid in the diagnosis of elevated intracranial pressure in the emergency department. This case report describes a 21-year-old female presenting with 4 months of mild headache and 2 weeks of recurrent, transient binocular vision loss. Though limited by patient discomfort, fundoscopic examination suggested the presence of blurred optic disc margins. Bedside ocular ultrasound (BOUS revealed wide optic nerve sheath diameters and bulging optic discs bilaterally. Lumbar puncture demonstrated a cerebrospinal fluid (CSF opening pressure of 54 cm H2O supporting the suspected diagnosis of idiopathic intracranial hypertension. Accurate fundoscopy can be vital to the appropriate diagnosis and treatment of patients with suspected elevated intracranial pressure, but it is often technically difficult or poorly tolerated by the photophobic patient. BOUS is a quick and easily learned tool to supplement the emergency physician’s fundoscopic examination and help identify patients with elevated intracranial pressure.

  7. Organic electronics based pressure sensor towards intracranial pressure monitoring

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    Rai, Pratyush; Varadan, Vijay K.

    2010-04-01

    The intra-cranial space, which houses the brain, contains cerebrospinal fluid (CSF) that acts as a fluid suspension medium for the brain. The CSF is always in circulation, is secreted in the cranium and is drained out through ducts called epidural veins. The venous drainage system has inherent resistance to the flow. Pressure is developed inside the cranium, which is similar to a rigid compartment. Normally a pressure of 5-15 mm Hg, in excess of atmospheric pressure, is observed at different locations inside the cranium. Increase in Intra-Cranial Pressure (ICP) can be caused by change in CSF volume caused by cerebral tumors, meningitis, by edema of a head injury or diseases related to cerebral atrophy. Hence, efficient ways of monitoring ICP need to be developed. A sensor system and monitoring scheme has been discussed here. The system architecture consists of a membrane less piezoelectric pressure sensitive element, organic thin film transistor (OTFT) based signal transduction, and signal telemetry. The components were fabricated on flexible substrate and have been assembled using flip-chip packaging technology. Material science and fabrication processes, subjective to the device performance, have been discussed. Capability of the device in detecting pressure variation, within the ICP pressure range, is investigated and applicability of measurement scheme to medical conditions has been argued for. Also, applications of such a sensor-OTFT assembly for logic sensor switching and patient specific-secure monitoring system have been discussed.

  8. The major influence of the atmosphere on intracranial pressure: an observational study

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    Herbowski, Leszek

    2017-01-01

    The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6 hPa (95 % CI 1004.5 to 1008.8 hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9 hPa (95 % CI 1006.3 to 1009.6 hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r = 0.87, p < 0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8 %). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

  9. The major influence of the atmosphere on intracranial pressure: an observational study

    Science.gov (United States)

    Herbowski, Leszek

    2016-06-01

    The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6 hPa (95 % CI 1004.5 to 1008.8 hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9 hPa (95 % CI 1006.3 to 1009.6 hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r = 0.87, p < 0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8 %). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

  10. The minor symptoms of increased intracranial pressure: 101 patients with benign intracranial hypertension.

    Science.gov (United States)

    Round, R; Keane, J R

    1988-09-01

    Of 101 patients with benign intracranial hypertension not related to vasculitis, neck stiffness occurred in 31, tinnitus in 27, distal extremity paresthesias in 22, joint pains in 13, low back pain in 5, and gait "ataxia" in 4. Symptoms resolved promptly upon lowering the intracranial pressure by lumbar puncture, and were probably directly caused by intracranial hypertension. Awareness of these "minor" symptoms of increased intracranial pressure can facilitate diagnosis and management.

  11. The Intracranial Volume Pressure Response in Increased Intracranial Pressure Patients: Clinical Significance of the Volume Pressure Indicator

    Science.gov (United States)

    2016-01-01

    Background For patients suffering from primary brain injury, monitoring intracranial pressure alone is not enough to reflect the dynamic intracranial condition. In our previous study, a segment of the pressure-volume curve can be expressed by the parabolic regression model with single indicator “a”. The aim of this study is to evaluate if the indicator “a” can reflect intracranial conditions. Methods Patients with traumatic brain injury, spontaneous intracranial hemorrhage, and/or hydrocephalus who had external ventricular drainage from January 2009 to February 2010 were included. The successive volume pressure response values were obtained by successive drainage of cerebral spinal fluid from intracranial pressure 20–25 mm Hg to 10 mm Hg. The relationship between withdrawn cerebral spinal fluid volume and intracranial pressure was analyzed by the parabolic regression model with single parameter “a”. Results The overall mean for indicator “a” was 0.422 ± 0.046. The mean of “a” in hydrocephalus was 0.173 ± 0.024 and in severe intracranial mass with slender ventricle, it was 0.663 ± 0.062. The two extreme intracranial conditions had a statistical significant difference (phydrocephalus. Brain computed tomography should be performed early if a rapid elevation of indicator “a” is detected, as it can reveal some ongoing intracranial pathology prior to clinical deterioration. Increased intracranial pressure was frequently observed in patients with intracranial pathology. The progression can be differentiated using the pattern of the volume pressure indicator. PMID:27723794

  12. Standardized Application of Laxatives and Physical Measures in Neurosurgical Intensive Care Patients Improves Defecation Pattern but Is Not Associated with Lower Intracranial Pressure

    Directory of Open Access Journals (Sweden)

    Martin Kieninger

    2014-01-01

    Full Text Available Background. Inadequate bowel movements might be associated with an increase in intracranial pressure in neurosurgical patients. In this study we investigated the influence of a structured application of laxatives and physical measures following a strict standard operating procedure (SOP on bowel movement, intracranial pressure (ICP, and length of hospital stay in patients with a serious acute cerebral disorder. Methods. After the implementation of the SOP patients suffering from a neurosurgical disorder received pharmacological and nonpharmacological measures to improve bowel movements in a standardized manner within the first 5 days after admission to the intensive care unit (ICU starting on day of admission. We compared mean ICP levels, length of ICU stay, and mechanical ventilation to a historical control group. Results. Patients of the intervention group showed an adequate defecation pattern significantly more often than the patients of the control group. However, this was not associated with lower ICP values, fewer days of mechanical ventilation, or earlier discharge from ICU. Conclusions. The implementation of a SOP for bowel movement increases the frequency of adequate bowel movements in neurosurgical critical care patients. However, this seems not to be associated with reduced ICP values.

  13. Increased Intracranial Pressure Following Removal of Intracranial Lesions

    Directory of Open Access Journals (Sweden)

    B. Ramamurthi

    1964-01-01

    Full Text Available Increased intracramal tension may 0 ise some days or ''leeks the problem may ari 1 of lrelUova "nt r a cra nial tumours or . lfter operation. , ""n" . " such increased tensicn raises the pOSS1- In the immed.',iate postoperat1ve perlOd" " f eopenino- Unrelieved tentorial -" d f c the dec1s10n or r O' lility of a clot rormattcn an ore ~ "e"ln .or the so called third day post " f thrombus Into a ma](Ir v .' , herniation. extenslOn 0 a f h raised intracranial pressure,. th common causes 0 sue operative oede~a. are e dematous blockage of ventricular system may When the ventnclc' has been opened. oe have to be tackled by repeated ventricular puncture. the fear of this postoperative oedema is the reason In posterior fossa surgery. '. - ' h many neurosuTgeons leave the dura open. w y " ommoner in posterior fossa " " tracranial presurc1 1S c Late onset of mcreased in f ttbromae or after excision of " b-total removal 0 neuro . operations spec1ally after su ti t the site of surgery or adheslOns block- " cyst forma ion a tubercnlomas. The cause :s Following air studies. a shunt procedure or a ing the cerebrospinal flUld "pa~hWay. tentorial incision would be md1cated.

  14. [Effects of solcoseryl on the cerebral blood flow, intracranial pressure, systemic blood pressure and EEG in acute intracranial hypertensive cats (author's transl)].

    Science.gov (United States)

    Kubota, S; Asakura, T; Kitamura, K

    1976-02-01

    The experiment was performed on 86 cases under intraperitoneal pentobarbital anesthesia. One balloon was placed in the extradural space of right frontal region, and the other balloon was placed in the left extradural space and the intracranial pressure was measured. A needle was stereotaxically inserted into the subcortical area in order to measure the cerebral blood flow. Systemic blood pressure was recorded by inserting a catheter into the femoral artery, and electrocorticogram was also recorded. An expanding intracranial lesion was made by inflating the extradural balloon with physiological saline. The animals were arbitrarily divided into two groups.: 1) light or moderate groups which intracranial pressure before the injection of drug was below 400 mmH2O. 2) severe groups above 400 mmH2O. After the maintenance of the pressure, Solcoseryl was infused intravenously. The investigation was focused to observe whether Solcoseryl reveales any potent effect on cerebral blood flow, intracranial pressure, systemic blood pressure and on electroencephalogram in acute intracranial hypertension. Results 1) Intravenous injection of Solcoseryl had the effect of lowering intracranial pressure in the light or moderate and severe groups. Particularly, dose of 80 mg/kg showed the marked effect, though with a rebound phenomenon in the light or moderate groups. Furthermore, the effect was more marked and lasting by drip infusion of Solcoseryl and also by intravenous injection of Solcoseryl after pretreatment with hydrocortisone, and at this time no rebound phenomenon was recognized. 2) Solcoseryl had the effect of increasing the cerebral blood flow accompained with the lowering of intracranial pressure. 3) Systemic blood pressure was transiently lowered by the injection of Solcoseryl 20 mg/kg or 80 mg/kg and recovered immediately. 4) Solcoseryl had no effect on electroencephalogram in the severe groups. Conclusion On the basis of these results, it is rational to conclude that

  15. Paradoxical presentation of orthostatic headache associated with increased intracranial pressure in patients with cerebral venous thrombosis

    Directory of Open Access Journals (Sweden)

    Jung B Kim

    2013-01-01

    Full Text Available Headache is the most common symptom of cerebral venous thrombosis (CVT; however, the detailed underlying mechanisms and characteristics of headache in CVT have not been well described. Here, we report two cases of CVT whose primary and lasting presentation was orthostatic headache, suggestive of decreased intracranial pressure. Contrary to our expectations, the headaches were associated with elevated cerebrospinal fluid (CSF pressure. Magnetic resonance imaging and magnetic resonance venography showed characteristic voiding defects consistent with CVT. We suggest that orthostatic headache can be developed in a condition of decreased intracranial CSF volume in both intracranial hypotensive and intracranial hypertensive states. In these cases, orthostatic headache in CVT might be caused by decreased intracranial CSF volume that leads to the inferior displacement of the brain and traction on pain-sensitive intracranial vessels, despite increased CSF pressure on measurement. CVT should be considered in the differential diagnosis when a patient complains of orthostatic headache.

  16. Can sonographic measurement of optic nerve sheath diameter be used to detect raised intracranial pressure in patients with tuberculous meningitis? A prospective observational study

    Directory of Open Access Journals (Sweden)

    Shruti V Sangani

    2015-01-01

    Full Text Available CNS Tuberculosis can manifest as meningitis, arachnoiditis and a tuberculoma. The rupture of a tubercle into the subarachnoid space leads to Tuberculosis Meningitis (TBME; the resulting hypersensitivity reaction can lead to an elevation of the intracranial pressure and hydrocephalus. While bedside optic nerve sheath diameter (ONSD ultrasonography (USG can be a sensitive screening test for elevated intracranial pressure in adult head injury, little is known regarding ONSD measurements in Tuberculosis Meningitis. Objectives: The aim of this study was to determine whether patients with TBME had dilation of the optic nerve sheath, as detected by ocular USG performed in the emergency department (ED. Materials and Methods: We conducted a prospective, observational study on adult ED patients with suspected TBME. Patients underwent USG measurements of the optic nerve followed by MRI. The ONSD was measured 3 mm behind the globe in each eye. MRI evidence of basilar meningeal enhancement and any degree of hydrocephalus was suggestive of TBME. Those patients without evidence of hydrocephalus subsequently underwent a lumbar puncture to confirm the diagnosis. Exclusion criteria were age less than 18 and obvious ocular pathology. In total, the optic nerve sheath diameters of 25 adults with confirmed TBME were measured. These measurements were compared with 120 control patients. Results: The upper limit of normal ONSD was 4.37 mm in control group. Those patients with TBME had a mean ONSD of 5.81 mm (SD 0.42. These results confirm that patients with tuberculosis meningitis have an ONSD in excess of the control data (P < 0.001. Conclusion: The evaluation of the ONSD is a simple non-invasive and potentially useful tool in the assessment of adults suspected of having TBME.

  17. Deformation of skull bone as intracranial pressure changing

    African Journals Online (AJOL)

    STORAGESEVER

    2009-03-06

    Mar 6, 2009 ... Key words: Deformation, skull bone, intracranial pressure, finite-element model, rat. ... air spontaneously, and the femoral arterial blood pressure was ..... pressure monitoring by flaccid-cuff catheter in an animal model. J.

  18. Use of intracranial pressure monitoring in bacterial meningitis

    DEFF Research Database (Denmark)

    Larsen, Lykke; Rom Poulsen, Frantz; Nielsen, Troels H

    2017-01-01

    BACKGROUND: The aim of this study was to evaluate the clinical outcome of patients with severe bacterial meningitis where intracranial pressure (ICP) monitoring has been performed. METHODS: A retrospective observational study including patients admitted 1st(.) January 2005 to 31st(.) December 2014...... = 0.034). Lower mean-cerebral perfusion pressure (CPP) was found to correlate with adverse outcome (p = 0.005). Cerebrospinal fluid (CSF) was drained in fourteen patients. Increased ICP (>20 mmHg) was observed in twenty four patients. No significant correlation was found between measured ICP and head...

  19. Visual Impairment/Intracranial Pressure Risk Assessment

    Science.gov (United States)

    Fogarty, Jennifer A.; Durham, T.; Otto, C.; Grounds, D.; Davis, J. R.

    2010-01-01

    Since 2006 there have been 6 reported cases of altered visual acuity and intracranial pressure (ICP) in long duration astronauts. In order to document this risk and develop an integrated approach to its mitigation, the NASA Space Life Sciences Directorate (SLSD) and Human Research Program (HRP) have chosen to use the Human System Risk Board (HSRB) and the risk management analysis tool (RMAT). The HSRB is the venue in which the stakeholders and customers discuss and vet the evidence and the RMAT is the tool that facilitates documentation and comparison of the evidence across mission profiles as well as identification of risk factors, and documentation of mitigation strategies. This process allows for information to be brought forward and dispositioned so that it may be properly incorporated into the RMAT and contribute to the design of the research and mitigation plans. The evidence thus far has resulted in the identification of a visual impairment/intracranial pressure (VIIP) project team, updating of both short and long duration medical requirements designed to assess visual acuity, and a research plan to characterize this issue further. In order to understand this issue more completely, a plan to develop an Accelerated Research Collaboration (ARC) has been approved by the HSRB. The ARC is a novel research model pioneered by the Myelin Repair Foundation. It is a patient centered research model that brings together researchers and clinicians, under the guidance of a scientific advisory panel, to collaborate and produce results much quickly than accomplished through traditional research models. The data and evidence from the updated medical requirements and the VIIP ARC will be reviewed at the HSRB on a regular basis. Each review package presented to the HSRB will include an assessment and recommendation with respect to continuation of research, countermeasure development, occupational surveillance modalities, selection criteria, etc. This process will determine the

  20. The Camino intracranial pressure device in clinical practice: reliability, handling characteristics and complications.

    Science.gov (United States)

    Münch, E; Weigel, R; Schmiedek, P; Schürer, L

    1998-01-01

    Intracranial pressure monitoring has a key role in the management of patients developing increased intracranial pressure (ICP). We adopted the Camino fiberoptic system for intracranial pressure measurement in 1993 in our neurosurgical department. The aim of this study was to investigate reliability, handling characteristics and complication rate of the Camino intracranial pressure device. In an eighteen month period, we prospectively investigated 118 patients with intracranial pathology undergoing Camino fiberoptic intraparenchymal or intraventricular ICP monitoring. The assessment of reliability of ICP monitoring according to patients clinical condition, to cranial computed tomography (CCT) findings and ICP waveform was carried out. Position of the probe and intracranial bleeding complications related to probe insertion were confirmed by CCT. Technical complications, as well as infections due to the device, were documented. In vivo recalibration was performed in 22 patients. At the end of the measuring period the drift of the probe was evaluated and the accuracy of the fiberoptic device was measured by performing a two point calibration. Recordings of intracranial pressure were carried out with 136 Camino devices (104 parenchymal, 32 ventricular) in 118 patients with an average measuring time of 94.1 +/- 79.1 hrs. One hundred and fifteen Camino intracranial pressure devices (85.2%) demonstrated reliability according to the predetermined clinical parameters. The actual mean drift after removal of the devices was 3.4 mmHg +/- 3.2 with an actual daily drift of 3.2 +/- 17.2 mmHg. Recorded complications included infection (0.7%), intraparenchymal haematoma (5.1%), and a high complication rate (23.5%) with regard to technical aspects. The Camino intracranial pressure system offers reliable ICP measurements in an acceptable percentage of devices, and the advantage of in vivo recalibration. The high incidence of technical complications identifies a need for improvement in

  1. Probabilistic Modeling of Intracranial Pressure Effects on Optic Nerve Biomechanics

    Science.gov (United States)

    Ethier, C. R.; Feola, Andrew J.; Raykin, Julia; Myers, Jerry G.; Nelson, Emily S.; Samuels, Brian C.

    2016-01-01

    Altered intracranial pressure (ICP) is involved/implicated in several ocular conditions: papilledema, glaucoma and Visual Impairment and Intracranial Pressure (VIIP) syndrome. The biomechanical effects of altered ICP on optic nerve head (ONH) tissues in these conditions are uncertain but likely important. We have quantified ICP-induced deformations of ONH tissues, using finite element (FE) and probabilistic modeling (Latin Hypercube Simulations (LHS)) to consider a range of tissue properties and relevant pressures.

  2. Diagnostic value of optical coherence tomography for intracranial pressure in idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Skau, M; Yri, H; Sander, B;

    2013-01-01

    , and 20 healthy controls. Investigations included measurement of peripapillary retinal nerve fiber layer thickness (RNFLT) and total retinal thickness (RT), automated visual field testing, and measurement of CSF opening pressure. An OCT elevation diagram was developed as a new diagnostic tool....... The diagnostic ability of OCT as a marker of increased ICP (> 25 cmH(2)O) was investigated using multiple regression and receiver operating characteristic (ROC) curves. RESULTS: OCT elevation diagrams showed that in 60 % of patients newly diagnosed with IIH and in 10 % of patients with long-term IIH, 50...... optic atrophy. The aim of this study was to evaluate the diagnostic value of optical coherence tomography (OCT) as a marker for CSF opening pressure in patients with idiopathic intracranial hypertension (IIH). METHODS: We conducted a case-control study of 20 newly diagnosed, 21 long-term IIH patients...

  3. Intracranial pressure following complete removal of a small demarcated brain tumor

    DEFF Research Database (Denmark)

    Andresen, Morten; Juhler, Marianne

    2014-01-01

    OBJECTIVES: Current published normal values for intracranial pressure (ICP) are extrapolated from lumbar CSF pressure measurements and ICP measurements in patients treated for CSF pressure disorders. There is an emerging agreement that true normal ICP values are needed for diagnostic and therapeu...... and the ICP target range in hydrocephalus treatment....

  4. Intracranial pressure monitoring in severe traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Apetrei Al. Cosmin

    2014-06-01

    Full Text Available Intracranial pressure monitoring seems to be an indispensable stage in management of severe traumatic brain injured patient. Since 2009, this technique completes our trauma protocol. The study has been carried out from 2011 to 2013 in Prof. Dr. N. Oblu hospital in Iasi. There have been included in the study patients with severe craniocerebral trauma, who had traumatic brain lesions CT detected and Glasgow score between 3 and 8. The age ranged from 16 to 60, an average of 35.5 years old. 50% of the studied cases had a favorable outcome. Diagrams associated to this category of patients showed increases in intracranial pressure above normal values but without repeated values above 50 mm Hg. Most of those patients had a good evolution under medical treatment. Monitoring intracranial pressure is an extremely useful stage in treating intracranial high pressure in traumatology and it should be included in the equipment of any intensive therapy section caring traumatic patients

  5. Harmonics tracking of intracranial and arterial blood pressure waves.

    Science.gov (United States)

    Shahsavari, Sima; McKelvey, Tomas

    2008-01-01

    Considering cardiorespiratory interaction and heart rate variability, a new approach is proposed to decompose intracranial pressure and arterial blood pressure to their different harmonics. The method is based on tracking the amplitudes of the harmonics by a Kalman filter based tracking algorithm. The algorithm takes benefit of combined frequency estimation technique which uses both Fast Fourier Transform and RR-interval detection. The result would be of use in intracranial pressure and arterial blood pressure waveform analysis as well as other investigations which need to estimate contribution of specific harmonic in above mentioned signals such as Pressure-Volume Compensatory Reserve assessment.

  6. Whole-body mathematical model for simulating intracranial pressure dynamics

    Science.gov (United States)

    Lakin, William D. (Inventor); Penar, Paul L. (Inventor); Stevens, Scott A. (Inventor); Tranmer, Bruce I. (Inventor)

    2007-01-01

    A whole-body mathematical model (10) for simulating intracranial pressure dynamics. In one embodiment, model (10) includes 17 interacting compartments, of which nine lie entirely outside of intracranial vault (14). Compartments (F) and (T) are defined to distinguish ventricular from extraventricular CSF. The vasculature of the intracranial system within cranial vault (14) is also subdivided into five compartments (A, C, P, V, and S, respectively) representing the intracranial arteries, capillaries, choroid plexus, veins, and venous sinus. The body's extracranial systemic vasculature is divided into six compartments (I, J, O, Z, D, and X, respectively) representing the arteries, capillaries, and veins of the central body and the lower body. Compartments (G) and (B) include tissue and the associated interstitial fluid in the intracranial and lower regions. Compartment (Y) is a composite involving the tissues, organs, and pulmonary circulation of the central body and compartment (M) represents the external environment.

  7. Recording of intracranial pressure in conscious rats via telemetry.

    Science.gov (United States)

    Guild, Sarah-Jane; McBryde, Fiona D; Malpas, Simon C

    2015-09-01

    Although cerebral perfusion pressure (CPP) is known to be fundamental in the control of normal brain function, there have been no previous long-term measurements in animal models. The aim of this study was to explore the stability and viability of long-term recordings of intracranial pressure (ICP) in freely moving rats via a telemetry device. We also developed a repeatable surgical approach with a solid-state pressure sensor at the tip of the catheter placed under the dura and in combination with arterial pressure (AP) measurement to enable the calculation of CPP. Telemeters with dual pressure catheters were implanted in Wistar rats to measure ICP and AP. We found that the signals were stable throughout the 28-day recording period with an average ICP value of 6 ± 0.8 mmHg. Significant light-dark differences were found in AP (3.1 ± 2.7 mmHg, P = 0.02) and HR (58 ± 12 beats/min, P = 0.003), but not ICP (0.3 ± 0.2 mmHg, P >0.05) or CPP (2.6 ± 2.8 mmHg, P > 0.05). Use of kaolin to induce hydrocephalus in several rats demonstrates the ability to measure changes in ICP throughout disease progression, validating this new solution for chronic measurement of ICP, CPP, and AP in conscious rats. Copyright © 2015 the American Physiological Society.

  8. Primary varicella infection presenting with headache and elevated intracranial pressure.

    Science.gov (United States)

    Gilad, Oded; Shefer-Averbuch, Noa; Garty, Ben Zion

    2015-05-01

    Primary varicella infection may be associated with neurologic complications, such as cerebritis and meningoencephalitis. Several cases of varicella infection with elevated intracranial pressure have been reported. We describe a 13-year-old immunocompetent girl who presented with a clinical picture of headaches and elevated intracranial pressure as the only manifestation of primary varicella zoster infection. The working diagnosis at first was pseudotumor cerebri based on complaints of headache of 2 weeks' duration, in addition to vomiting and papilledema, without fever or skin eruption. On lumbar puncture, opening pressure was 420 mmH2O, but mild pleocytosis and mildly elevated protein level ruled out the diagnosis of pseudotumor cerebri. Our patient had no history of previous varicella infection, and she did not receive the varicella zoster vaccine. Serology tests, done on admission and repeated 2 months later, suggested primary varicella infection. The literature on varicella infection associated with pseudotumor cerebri or elevated intracranial pressure is reviewed.

  9. The tympanic membrane displacement analyser for monitoring intracranial pressure in children

    OpenAIRE

    Gwer, Samson; Sheward, Victoria; Birch, Anthony; Marchbanks, Robert; Idro, Richard; Newton, Charles R.; Kirkham, Fenella J; Lin, Jean-Pierre; Lim, Ming

    2013-01-01

    Purpose Raised intracranial pressure (ICP) is a potentially treatable cause of morbidity and mortality but tools for monitoring are invasive. We sought to investigate the utility of the tympanic membrane displacement (TMD) analyser for non-invasive measurement of ICP in children. Methods We made TMD observations on normal and acutely comatose children presenting to Kilifi District Hospital (KDH) at the rural coast of Kenya and on children on follow-up for idiopathic intracranial hypertension ...

  10. The tympanic membrane displacement analyser for monitoring intracranial pressure in children

    OpenAIRE

    Gwer, Samson; Sheward, Victoria; Birch, Anthony; Marchbanks, Robert; Idro, Richard; Newton, Charles R; Kirkham, Fenella J.; Lin, Jean-Pierre; Lim, Ming

    2013-01-01

    Purpose Raised intracranial pressure (ICP) is a potentially treatable cause of morbidity and mortality but tools for monitoring are invasive. We sought to investigate the utility of the tympanic membrane displacement (TMD) analyser for non-invasive measurement of ICP in children. Methods We made TMD observations on normal and acutely comatose children presenting to Kilifi District Hospital (KDH) at the rural coast of Kenya and on children on follow-up for idiopathic intracranial hypertension ...

  11. Desflurane increases intracranial pressure more and sevoflurane less than isoflurane in pigs subjected to intracranial hypertension.

    Science.gov (United States)

    Holmström, Anders; Akeson, J

    2004-04-01

    Desflurane and sevoflurane may have advantages over isoflurane in neuroanesthesia, but this is still under debate. A porcine model with experimental intracranial hypertension was used for paired comparison of desflurane, sevoflurane, and isoflurane with respect to the effects on cerebral blood flow (CBF), cerebrovascular resistance (CVR), and intracranial pressure (ICP). The agents, given in sequence to each of six pigs, were compared at 0.5 and 1.0 minimal alveolar concentrations (MAC) and three mean arterial blood pressure (MAP) levels (50, 70, and 90 mm Hg) at normocapnia and one MAP level (70 mm Hg) at hypocapnia. MAC for each agent had been previously determined in a standardized manner for comparison reliability. CBF was measured with Xe. MAP was lowered by inflation of a balloon catheter in the inferior caval vein and raised by inflation of a balloon catheter in the descending aorta. ICP was measured intraparenchymally. Two Fogarty catheters positioned extradurally were inflated to a baseline ICP of 20 to 22 mm Hg at 0.2 MAC of each agent. CBF and ICP with the three agents at normocapnia and MAP 70 and 90 mm Hg at both 0.5 and 1.0 MAC were as follows (P isoflurane > sevoflurane. None of the agents abolished CO2 reactivity. High-dose desflurane resulted in a higher CBF at hypocapnia than corresponding doses of sevoflurane or isoflurane, but there were no significant differences between the agents in ICP at hypocapnia. The present study showed that desflurane increased ICP more and sevoflurane less than isoflurane during normoventilation, but the differences disappeared with hyperventilation.

  12. Pulsatile Intracranial Pressure and Cerebral Autoregulation After Traumatic Brain Injury

    NARCIS (Netherlands)

    Radolovich, D. K.; Aries, M.J.H.; Castellani, G.; Corona, A.; Lavinio, A.; Smielewski, P.; Pickard, J. D.; Czosnyka, M.

    2011-01-01

    Strong correlation between mean intracranial pressure (ICP) and its pulse wave amplitude (AMP) has been demonstrated in different clinical scenarios. We investigated the relationship between invasive mean arterial blood pressure (ABP) and AMP to explore its potential role as a descriptor of cerebrov

  13. Significant practice pattern variations associated with intracranial pressure monitoring.

    Science.gov (United States)

    Olson, DaiWai M; Lewis, Lisa S; Bader, Mary Kay; Bautista, Cynthia; Malloy, Rachel; Riemen, Kristina E; McNett, Molly M

    2013-08-01

    The purpose of this study was to describe nursing practice in the care of patients with intracranial pressure monitoring. Although standards for care of such patients have been established, there continue to be variations in the nursing practice. This was an observational study in which data were collected from 28 nurse-patient dyads at 16 different hospitals across the United States. Each dyad was observed for 2 hours; nursing actions and patient responses including intracranial pressure readings were documented. Differences in the care of patients with intracranial pressure monitoring were prevalent. Variations in practice were prompted by healthcare provider prescriptions as well as nursing decisions. Prescriptions and interventions were often not supported by the available scientific evidence. For more insights from the authors, see Supplemental Digital Content 1, at http://links.lww.com/JNN/A7.

  14. Lack of relationship between resistance to cerebrospinal fluid outflow and intracranial pressure in normal pressure hydrocephalus.

    Science.gov (United States)

    Eide, P K; Fremming, A D; Sorteberg, A

    2003-12-01

    To explore whether calculation of resistance to cerebrospinal fluid (CSF) outflow (Rout) by the lumbar constant rate infusion test in a reliable way predicts the intracranial pressure (ICP) profile in normal pressure hydrocephalus (NPH). A prospective study was undertaken including 16 cases with clinical signs of normal pressure hydrocephalus that were investigated with both continuous ICP monitoring and the lumbar constant rate infusion test. Intracranial pressure monitoring was performed for about 24 h, and supplied with a simultaneous lumbar constant rate infusion test at the end of the monitoring period. The pressure recordings were analysed using the Sensometrics Pressure Analyser. Various characteristics of the pressure curves were compared. The continuous ICP recordings were considered as normal (mean ICP or =12.0 mmHg/ml/min) in 12 of 16 cases. There was no relationship between lumbar Rout and mean ICP during sleep. We could not find any relationship between lumbar Rout and number of nightly ICP elevations of 1525 mmHg lasting 0.5 or 1 min. Neither resistance to CSF outflow (Rout) nor mean ICP during sleep was related to the ventricular size. The results of this prospective study revealed no significant relationship between resistance to CSF outflow (Rout) and the ICP profile in NPH cases. The results also suggest that caution should be made when predicting the ICP profile on the basis of measuring the lumbar CSF pressure for a few minutes duration.

  15. Biotelemetric Wireless Intracranial Pressure Monitoring: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Mohammad H. Behfar

    2015-01-01

    Full Text Available Assessment of intracranial pressure (ICP is of great importance in management of traumatic brain injuries (TBIs. The existing clinically established ICP measurement methods require catheter insertion in the cranial cavity. This increases the risk of infection and hemorrhage. Thus, noninvasive but accurate techniques are attractive. In this paper, we present two wireless, batteryless, and minimally invasive implantable sensors for continuous ICP monitoring. The implants comprise ultrathin (50 μm flexible spiral coils connected in parallel to a capacitive microelectromechanical systems (MEMS pressure sensor. The implantable sensors are inductively coupled to an external on-body reader antenna. The ICP variation can be detected wirelessly through measuring the reader antenna’s input impedance. This paper also proposes novel implant placement to improve the efficiency of the inductive link. In this study, the performance of the proposed telemetry system was evaluated in a hydrostatic pressure measurement setup. The impact of the human tissues on the inductive link was simulated using a 5 mm layer of pig skin. The results from the in vitro measurement proved the capability of our developed sensors to detect ICP variations ranging from 0 to 70 mmHg at 2.5 mmHg intervals.

  16. Inner ear pressure changes following square wave intracranial or ear canal pressure manipulation in the same guinea pig

    NARCIS (Netherlands)

    Thalen, E; Wit, H; Segenhout, H; Albers, F

    Inner ear pressure was measured in scala tympani with a micropipette during square wave pressure manipulation of the intracranial compartment and, subsequently, of the external ear canal (EEC) in the same guinea pig. As expected, the combination of the cochlear aqueduct and the inner ear behaves as

  17. Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation.

    Science.gov (United States)

    Brändström, Helge; Sundelin, Anna; Hoseason, Daniela; Sundström, Nina; Birgander, Richard; Johansson, Göran; Winsö, Ola; Koskinen, Lars-Owe; Haney, Michael

    2017-05-12

    Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

  18. Visual evoked potentials show strong positive association with intracranial pressure in patients with cryptococcal meningitis

    Directory of Open Access Journals (Sweden)

    Marcelo Adriano da Cunha Silva Vieira

    2015-04-01

    Full Text Available Objective : To verify the relationship between intracranial pressure and flash visual evoked potentials (F-VEP in patients with cryptococcal meningitis. Method The sample included adults diagnosed with cryptococcal meningitis admitted at a reference hospital for infectious diseases. The patients were subjected to F-VEP tests shortly before lumbar puncture. The Pearson’s linear correlation coefficient was calculated and the linear regression analysis was performed. Results : Eighteen individuals were subjected to a total of 69 lumbar punctures preceded by F-VEP tests. At the first lumbar puncture performed in each patient, N2 latency exhibited a strong positive correlation with intracranial pressure (r = 0.83; CI = 0.60 - 0.94; p < 0.0001. The direction of this relationship was maintained in subsequent punctures. Conclusion : The intracranial pressure measured by spinal tap manometry showed strong positive association with the N2 latency F-VEP in patients with cryptococcal meningitis.

  19. Intracranial pressure and cerebrospinal fluid outflow conductance in healthy subjects.

    Science.gov (United States)

    Albeck, M J; Børgesen, S E; Gjerris, F; Schmidt, J F; Sørensen, P S

    1991-04-01

    Conductance of cerebrospinal fluid (CSF) outflow (Cout) is an important parameter to be considered in patients with CSF circulation abnormalities. In patients with normal-pressure hydrocephalus it is the single most important parameter in determining if the patient needs CSF shunting. The lower normal limit for Cout has been estimated from the effect of shunting in patients with normal-pressure hydrocephalus, from patients retrospectively reevaluated after recovering from illness, and from patients with known abnormalities in the brain or the CSF system. The true value of Cout in normal individuals, however, has hitherto not been reported. In the present study, Cout has been measured by a lumbar infusion test in eight young volunteers with no suspicion of disease. The mean intracranial pressure (ICP) was 11 mm Hg and a linear relationship was found between CSF absorption and ICP. The mean Cout was 0.11 ml/min/mm Hg and the lower 95% confidence level was 0.10 ml/min/mm Hg. These values are in accordance with those obtained from previous studies.

  20. PATHOGENESIS OF OPTIC DISC EDEMA IN RAISED INTRACRANIAL PRESSURE

    Science.gov (United States)

    Hayreh, Sohan Singh

    2015-01-01

    Optic disc edema in raised intracranial pressure was first described in 1853. Ever since, there has been a plethora of controversial hypotheses to explain its pathogenesis. I have explored the subject comprehensively by doing basic, experimental and clinical studies. My objective was to investigate the fundamentals of the subject, to test the validity of the previous theories, and finally, based on all these studies, to find a logical explanation for the pathogenesis. My studies included the following issues pertinent to the pathogenesis of optic disc edema in raised intracranial pressure: the anatomy and blood supply of the optic nerve, the roles of the sheath of the optic nerve, of the centripetal flow of fluids along the optic nerve, of compression of the central retinal vein, and of acute intracranial hypertension and its associated effects. I found that, contrary to some previous claims, an acute rise of intracranial pressure was not quickly followed by production of optic disc edema. Then, in rhesus monkeys, I produced experimentally chronic intracranial hypertension by slowly increasing in size space-occupying lesions, in different parts of the brain. Those produced raised cerebrospinal fluid pressure (CSFP) and optic disc edema, identical to those seen in patients with elevated CSFP. Having achieved that, I investigated various aspects of optic disc edema by ophthalmoscopy, stereoscopic color fundus photography and fluorescein fundus angiography, and light microscopic, electron microscopic, horseradish peroxidase and axoplasmic transport studies, and evaluated the effect of opening the sheath of the optic nerve on the optic disc edema. This latter study showed that opening the sheath resulted in resolution of optic disc edema on the side of the sheath fenestration, in spite of high intracranial CSFP, proving that a rise of CSFP in the sheath was the essential pre-requisite for the development of optic disc edema. I also investigated optic disc edema with

  1. Furosemide lowers intracranial pressure by inhibiting CSF production.

    Science.gov (United States)

    Lorenzo, A V; Hornig, G; Zavala, L M; Boss, V; Welch, K

    1986-12-01

    Furosemide administration effectively lowers intracranial pressure in newborn preterm and term rabbit pups. This effect may be due to the diuretic action of the drug, its ability to inhibit cerebrospinal fluid production or to a combination of both. To test these possibilities newborn rabbits were either injected with furosemide and left unmolested for 6 hours, or anaesthetized and subjected to ventriculocisternal perfusions. During the 6 hour postnatal period the decrease in body weight was 8 times greater in furosemide than in saline treated pups. However, no difference was noted between the average brain weights of these two groups. Secondary effects of the diuretic were noted in blood (12.5% increase in the haematocrit over control value) and in muscle in which tissue water content and NA+ concentration were decreased while K+ concentration was increased. The fact that these parameters remained unchanged in brain suggests that the lowering of intracranial pressure was not attributable to the secondary effects of the diuretic agent. However, the marked reduction in cerebrospinal production noted following furosemide administration indicates that in newborn rabbits this may represent the primary mechanism by which furosemide lowers intracranial pressure.

  2. Measurement of blood flow in the superior sagittal sinus in healthy volunteers, and in patients with normal pressure hydrocephalus and idiopathic intracranial hypertension with phase-contrast cine MR imaging

    DEFF Research Database (Denmark)

    Gideon, P; Thomsen, C; Gjerris, F

    1996-01-01

    PURPOSE: To measure blood flow and velocity in the superior sagittal ++sinus. MATERIAL AND METHODS: MR velocity mapping was used to examine 14 healthy volunteers, 15 patients with normal pressure hydrocephalus (NPH), 3 patients with high pressure hydrocephalus (HPH), and 11 patients with idiopathic...... intracranial hypertension (IIH). RESULTS: Mean blood flow was 443 ml/min in healthy volunteers with a tendency towards reduced blood flow with increasing age. In NPH patients significantly lower superior sagittal sinus blood flow values were found, but this difference was no longer significant when patients...... and controls were matched for age. In HPH and IIH patients blood flow and velocity were within the normal range. In one patient with thrombosis of the superior sagittal sinus the blood flow was reduced to 40 ml/min. CONCLUSION: MR velocity mapping methods may be of value in the assessment of blood flow...

  3. Invasive intracranial arterial pressure monitoring during endovascular cerebral aneurysms embolization for cerebral perfusion evaluation.

    Science.gov (United States)

    Netlyukh, Andriy M; Shevaga, Volodymyr M; Yakovenko, Leonid M; Payenok, Angelika V; Salo, Victor M; Kobyletskiy, Oleg Ja

    2015-01-01

    The purpose of the study was to define a method of estimation of cerebral blood flow by a determination of parameters of the hemodynamics during neuroendovascular procedures. Materials and Methods. Extracranial and intracranial mean arterial pressure (MAP) was invasively monitored with the help of a transducing system during an endovascular coiling procedure in 19 patients. The measurements were performed at the tip of the guiding catheter and microcatheter placed into internal carotid artery (ICA) C1 segments and of the microcatheter placed into C4 ICA segments, at different stages of the aneurysm repair. Results. As measured, the diameter of the ICA in the C1 and C4 segments did not differ substantially. MAP in the ICA was determined to be 91.2 ± 9.6 mmHg in the skull cavity, and 102.4 ± 6.3 mmHg outside of the skull cavity, with an average difference of 9.2 ± 3.0 mmHg. Conclusion. The difference in MAP, as measured in the ICA outside and inside the skull cavity, was ascribed to the influence of intracranial pressure. Further investigation is required to check the accuracy of invasive intra-arterial pressure recording for an objective and direct measurement of the cerebral perfusion in reference to the intracranial pressure level.

  4. Dynamics of inner ear pressure change caused by intracranial pressure manipulation in the guinea pig

    NARCIS (Netherlands)

    Thalen, EO; Wit, HP; Segenhout, JM; Albers, FWJ

    2001-01-01

    Previous studies have shown that pressure changes in the cerebrospinal fluid compartment are transmitted to the inner ear. The main route for pressure transfer is the cochlear aqueduct, about which little is known with regard to its dynamic properties. In the present study, sudden intracranial press

  5. Dynamics of inner ear pressure change caused by intracranial pressure manipulation in the guinea pig

    NARCIS (Netherlands)

    Thalen, EO; Wit, HP; Segenhout, JM; Albers, FWJ

    Previous studies have shown that pressure changes in the cerebrospinal fluid compartment are transmitted to the inner ear. The main route for pressure transfer is the cochlear aqueduct, about which little is known with regard to its dynamic properties. In the present study, sudden intracranial

  6. Zero drift of intraventricular and subdural intracranial pressure monitoring systems

    OpenAIRE

    2013-01-01

    【Abstract】Objective: To assess zero drift of intra-ventricular and subdural intracranial pressure (ICP) moni-toring systems. Methods: A prospective study was conducted in pa-tients who received Codman ICP monitoring in the neuro-surgical department from January 2010 to December 2011. According to the location of sensors, the patients were ca-tegorized into two groups: intraventricular group and sub-dural group. Zero drift between the two groups and its as-sociation with the duratio...

  7. Visual Impairment/Increased Intracranial Pressure (VIIP): Layman's Summary

    Science.gov (United States)

    Fogarty, Jennifer

    2011-01-01

    To date NASA has documented that seven long duration astronauts have experienced in-flight and post-flight changes in vision and eye anatomy including degraded distant vision, swelling of the back of the eye, and changes in the shape of the globe. We have also documented in a few of these astronauts post-flight, increases in the pressure of the fluid that surrounds the brain and spinal cord. This is referred to as increased intracranial pressure (ICP). The functional and anatomical changes have varied in severity and duration. In the post-flight time period, some individuals have experienced a return to a pre-flight level of visual function while others have experienced changes that remain significantly altered compared to pre-flight. In addition, the increased ICP also persists in the post-flight time period. Currently, the underlying cause or causes of these changes is/are unknown but the spaceflight community at NASA suspects that the shift of blood toward the head and the changes in physiology that accompany it, such as increased intracranial pressure, play a significant role.

  8. Correlation of the intraocular pressure with increased intracranial pressure in rabbits

    Directory of Open Access Journals (Sweden)

    Eskandari H

    2000-08-01

    Full Text Available Although measurement of intracranial pressure by noninvasive methods has been suggested, but mainly invasive methods are used for this purpose-Increase in episcleral venous pressure can be expected to result in a linear increase in intraocular pressure. Congested oculat veins with capillary leakage and hemorrhage are seen when the ICP is increased, thus theoretically measurement of intraocular pressure can be a procedure for estimation of the ICP. This study was performed to find whether there is andy relationship between intraocular pressure and ICP, so we used 12 albino rabbits in two divided groups. Our study was not designed to elucidate the mechanism of change but merely to record any changes observed. All measures except an increase in ICP were applied on the test group as well as on the control group. After general anesthesia with the combination of ketamin, rampune, and pentobarbital a burr hole was made in the lambda region of the skull and a cannula was placed in the subdural space. The ICP in the test group increased up to 15 mmHg and was constant throughout the experiment. Intraocular pressure was measured by Schiotz tonometers afte general anesthesia, after cannulation of the skull, and immediately after increasing the ICP which was repated in 15 minutes interval for 4 hours. There was no statistical difference between the two groups (P:0.997 . results show that neither cannulation nor general anesthesia for 4 hours produce alteration in IOP in the control group nor increasing of the ICP to level of 15 mmHg produces any alteration in IOP on the test group.

  9. [Monitoring of intracranial pressure difference between supra- and infratentorial spaces after posterior fossa tumor removal (case report)].

    Science.gov (United States)

    Oshorov, A V; Savin, I A; Goriachev, A S; Popugaev, K A; Lubnin, A Iu

    2011-01-01

    A clinical example shows that after a neurosurgical operation in posterior fossa there could appear intracranial pressure difference between supra- and infratentorial spaces. This difference develops due to pressure rise in posterior fossa and maintenance of this hypertension postoperatively. Hypertension in posterior fossa and intracranial difference are accompanied by brainstem reactions and temporary neurological disorders. While the pressure difference decreases and ICP in posterior fossa normalizes the neurological symptoms disappear. ICP in supratentorial space not necessarily correlates with ICP in infratentorial space. In some cases it is necessary to measure ICP in infratentorial space after posterior fossa surgery.

  10. Antiphospholipid Antibody Syndrome: Raised Intracranial Pressure Without Cerebral Venous Sinus Thrombosis.

    Science.gov (United States)

    Rudich, Danielle S; Yun, Samuel H; Liebling, Anne; Silbert, Jonathan E; Moeckel, Gilbert W; Lesser, Robert L

    2015-12-01

    Antiphospholipid antibody syndrome (APS) has been reported to cause elevated intracranial pressure, but usually this is due to cerebral venous sinus thrombosis (CVST). We present a 36-year old man with APS with elevated intracranial pressure with neuro-ophthalmic, renal and hematological involvement without identifiable CVST.

  11. Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring.

    Science.gov (United States)

    Dias, Celeste; Maia, Isabel; Cerejo, Antonio; Smielewski, Peter; Paiva, José-Artur; Czosnyka, Marek

    2016-01-01

    The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.

  12. Critical thresholds of intracranial pressure and cerebral perfusion pressure related to age in paediatric head injury

    Science.gov (United States)

    Chambers, I R; Jones, P A; Lo, T Y M; Forsyth, R J; Fulton, B; Andrews, P J D; Mendelow, A D; Minns, R A

    2006-01-01

    Background The principal strategy for managing head injury is to reduce the frequency and severity of secondary brain insults from intracranial pressure (ICP) and cerebral perfusion pressure (CPP), and hence improve outcome. Precise critical threshold levels have not been determined in head injured children. Objective To create a novel pressure–time index (PTI) measuring both duration and amplitude of insult, and then employ it to determine critical insult thresholds of ICP and CPP in children. Methods Prospective, observational, physiologically based study from Edinburgh and Newcastle, using patient monitored blood pressure, ICP, and CPP time series data. The PTI for ICP and CPP for 81 children, using theoretical values derived from physiological norms, was varied systematically to derive critical insult thresholds which delineate Glasgow outcome scale categories. Results The PTI for CPP had a very high predictive value for outcome (receiver operating characteristic analyses: area under curve = 0.957 and 0.890 for mortality and favourable outcome, respectively) and was more predictive than for ICP. Initial physiological values most accurately predicted favourable outcome. The CPP critical threshold values determined for children aged 2–6, 7–10, and 11–15 years were 48, 54, and 58 mm Hg. respectively. Conclusions The PTI is the first substantive paediatric index of total ICP and CPP following head injury. The insult thresholds generated are identical to age related physiological values. Management guidelines for paediatric head injuries should take account of these CPP thresholds to titrate appropriate pressor therapy. PMID:16103043

  13. Brain herniation in a patient with apparently normal intracranial pressure: a case report

    Directory of Open Access Journals (Sweden)

    Dahlqvist Mats B

    2010-08-01

    Full Text Available Abstract Introduction Intracranial pressure monitoring is commonly implemented in patients with neurologic injury and at high risk of developing intracranial hypertension, to detect changes in intracranial pressure in a timely manner. This enables early and potentially life-saving treatment of intracranial hypertension. Case presentation An intraparenchymal pressure probe was placed in the hemisphere contralateral to a large basal ganglia hemorrhage in a 75-year-old Caucasian man who was mechanically ventilated and sedated because of depressed consciousness. Intracranial pressures were continuously recorded and never exceeded 17 mmHg. After sedation had been stopped, our patient showed clinical signs of transtentorial brain herniation, despite apparently normal intracranial pressures (less than 10 mmHg. Computed tomography revealed that the size of the intracerebral hematoma had increased together with significant unilateral brain edema and transtentorial herniation. The contralateral hemisphere where the intraparenchymal pressure probe was placed appeared normal. Our patient underwent emergency decompressive craniotomy and was tracheotomized early, but did not completely recover. Conclusions Intraparenchymal pressure probes placed in the hemisphere contralateral to an intracerebral hematoma may dramatically underestimate intracranial pressure despite apparently normal values, even in the case of transtentorial brain herniation.

  14. Intracranial pressure monitoring and outcomes after traumatic brain injury

    Science.gov (United States)

    Lane, Peter L.; Skoretz, Terry G.; Doig, Gordon; Girotti, Murray J.

    2000-01-01

    Objective Uncontrolled intracranial hypertension after traumatic brain injury (TBI) contributes significantly to the death rate and to poor functional outcome. There is no evidence that intracranial pressure (ICP) monitoring alters the outcome of TBI. The objective of this study was to test the hypothesis that insertion of ICP monitors in patients who have TBI is not associated with a decrease in the death rate. Design Study of case records. Methods The data files from the Ontario Trauma Registry from 1989 to 1995 were examined. Included were all cases with an Injury Severity Score (ISS) greater than 12 from the 14 trauma centres in Ontario. Cases identifying a Maximum Abbreviated Injury Scale score in the head region (MAIS head) greater than 3 were selected for further analysis. Logistic regression analyses were conducted to investigate the relationship between ICP and death. Results Of 9001 registered cases of TBI, an MAIS head greater than 3 was recorded in 5507. Of these patients, 541 (66.8% male, mean age 34.1 years) had an ICP monitor inserted. Their average ISS was 33.4 and 71.7% survived. There was wide variation among the institutions in the rate of insertion of ICP monitors in these patients (ranging from 0.4% to over 20%). Univariate logistic regression indicated that increased MAIS head, ISS, penetrating trauma and the insertion of an ICP monitor were each associated with an increased death rate. However, multivariate analyses controlling for MAIS head, ISS and injury mechanism indicated that ICP monitoring was associated with significantly improved survival (p < 0.015). Conclusions ICP monitor insertion rates vary widely in Ontario’s trauma hospitals. The insertion of an ICP monitor is associated with a statistically significant decrease in death rate among patients with severe TBI. This finding strongly supports the need for a prospective randomized trial of management protocols, including ICP monitoring, in patients with severe TBI. PMID:11129833

  15. Waveform descriptor for pulse onset detection of intracranial pressure signal.

    Science.gov (United States)

    Yang, Li; Zhao, Mingxi; Peng, Chenglin; Hu, Xiao; Feng, Hua; Ji, Zhong

    2012-03-01

    We present an algorithm to identify the onset of intracranial pressure (ICP) pulses. The algorithm creates a waveform descriptor to extract the feature of each local minimum of the waveform and then identifies the onset by comparing the feature with a customized template. The waveform descriptor is derived by transforming the vectors connecting a given point and the local waveform samples around it into log-polar coordinates and ranking them into uniform bins. Using an ICP dataset consisting of 40933 normal beats and 306 segments of artifacts and noise, we investigated the performance of our algorithm (waveform descriptor, WD), global minimum within a sliding window (GM) and two other algorithms originally proposed for arterial blood pressure (ABP) signal (slope sum function, SSF and pulse waveform delineator, PUD). As a result, all the four algorithms showed good performance and WD showed overall better one. At a tolerance level of 30 ms (i.e., the predicted onset and ground truth were considered as correctly matched if the distance between the two was equal or less than 30 ms), WD achieved a sensitivity of 0.9723 and PPV of 0.9475, GM achieved a sensitivity of 0.9226 and PPV of 0.8968, PUD achieved a sensitivity of 0.9599 and PPV of 0.9327 and SSF, a sensitivity of 0.9720 and PPV of 0.9136. The evaluation indicates that the algorithms are effective for identifying the onset of ICP pulses.

  16. Assessment of continuous intracranial pressure recordings in childhood craniosynostosis.

    Science.gov (United States)

    Eide, Per Kristian; Helseth, Eirik; Due-Tønnessen, Bernt; Lundar, Tryggve

    2002-12-01

    In this study, we explored two strategies of assessing continuous intracranial pressure (ICP) recordings in children with craniosynostosis, namely either by computation of the mean ICP or by computation of the accurate numbers of ICP elevations of different durations. The ICP recordings of 121 consecutive patients with a tentative diagnosis of craniosynostosis who underwent continuous ICP monitoring were examined. The relationship between mean ICP and numbers of ICP elevations was defined. The distribution of numbers of ICP elevations between patients either undergoing surgery or conservative treatment was also compared, since the choice of treatment was heavily dependent on the results of ICP monitoring. At the time of ICP monitoring, calculation of mean ICP was the main parameter for assessment of ICP curves. After a median observation period of 16 months, the ICP curves were reexamined by means of the software Sensometrics Pressure Analyser, which presents the ICP curve as a matrix of numbers of ICP elevations of different levels (20-40 mm Hg) and durations (0.5- 20 min). Since the recording period differed between the cases, the numbers were standardized to a given recording time of 10 h, to allow for comparisons between patients. Cases with a borderline mean ICP during sleep (mean ICP 10-15 mm Hg) constituted 40.5% of the 121 patients. In this group, a rather weak relationship between mean ICP and the number of ICP elevations above 20 mm Hg was found, as well as a relatively high number of ICP elevations above 20 mm Hg of various durations. As compared to the patients undergoing surgery, a rather high number of ICP elevations above 20 mm Hg of various durations was found in patients undergoing conservative treatment. The study confirmed our hypothesis that in children with craniosynostosis, calculation of mean ICP does not describe the ICP curve in a reliable way. Decision-making should also include the computation of the distribution of numbers of ICP

  17. A novel rat model to study the role of intracranial pressure modulation on optic neuropathies.

    Directory of Open Access Journals (Sweden)

    Uttio Roy Chowdhury

    Full Text Available Reduced intracranial pressure is considered a risk factor for glaucomatous optic neuropathies. All current data supporting intracranial pressure as a glaucoma risk factor comes from retrospective and prospective studies. Unfortunately, there are no relevant animal models for investigating this link experimentally. Here we report a novel rat model that can be used to study the role of intracranial pressure modulation on optic neuropathies. Stainless steel cannulae were inserted into the cisterna magna or the lateral ventricle of Sprague-Dawley and Brown Norway rats. The cannula was attached to a pressure transducer connected to a computer that recorded intracranial pressure in real-time. Intracranial pressure was modulated manually by adjusting the height of a column filled with artificial cerebrospinal fluid in relation to the animal's head. After data collection the morphological appearance of the brain tissue was analyzed. Based on ease of surgery and ability to retain the cannula, Brown Norway rats with the cannula implanted in the lateral ventricle were selected for further studies. Baseline intracranial pressure for rats was 5.5 ± 1.5 cm water (n=5. Lowering of the artificial cerebrospinal fluid column by 2 cm and 4 cm below head level reduced ICP to 3.7 ± 1.0 cm water (n=5 and 1.5 ± 0.6 cm water (n=4, a reduction of 33.0% and 72.7% below baseline. Raising the cerebrospinal fluid column by 4 cm increased ICP to 7.5 ± 1.4 cm water (n=2 corresponding to a 38.3% increase in intracranial pressure. Histological studies confirmed correct cannula placement and indicated minimal invasive damage to brain tissues. Our data suggests that the intraventricular cannula model is a unique and viable model that can be used to study the effect of altered intracranial pressure on glaucomatous optic neuropathies.

  18. Intracranial Pressure Influences the Behavior of the Optic Nerve Head.

    Science.gov (United States)

    Hua, Yi; Tong, Junfei; Ghate, Deepta; Kedar, Sachin; Gu, Linxia

    2017-03-01

    In this work, the biomechanical responses of the optic nerve head (ONH) to acute elevations in intracranial pressure (ICP) were systematically investigated through numerical modeling. An orthogonal experimental design was developed to quantify the influence of ten input factors that govern the anatomy and material properties of the ONH on the peak maximum principal strain (MPS) in the lamina cribrosa (LC) and postlaminar neural tissue (PLNT). Results showed that the sensitivity of ONH responses to various input factors was region-specific. In the LC, the peak MPS was most strongly dependent on the sclera thickness, LC modulus, and scleral canal size, whereas in the PLNT, the peak MPS was more sensitive to the scleral canal size, neural tissue modulus, and pia mater modulus. The enforcement of clinically relevant ICP in the retro-orbital subarachnoid space influenced the sensitivity analysis. It also induced much larger strains in the PLNT than in the LC. Moreover, acute elevation of ICP leads to dramatic strain distribution changes in the PLNT, but had minimal impact on the LC. This work could help to better understand patient-specific responses, to provide guidance on biomechanical factors resulting in optic nerve diseases, such as glaucoma, papilledema, and ischemic optic neuropathy, and to illuminate the possibilities for exploiting their potential to treat and prevent ONH diseases.

  19. Reducing false intracranial pressure alarms using morphological waveform features.

    Science.gov (United States)

    Scalzo, Fabien; Liebeskind, David; Hu, Xiao

    2013-01-01

    False alarms produced by patient monitoring systems in intensive care units are a major issue that causes alarm fatigue, waste of human resources, and increased patient risks. While alarms are typically triggered by manually adjusted thresholds, the trend and patterns observed prior to threshold crossing are generally not used by current systems. This study introduces and evaluates, a smart alarm detection system for intracranial pressure signal (ICP) that is based on advanced pattern recognition methods. Models are trained in a supervised fashion from a comprehensive dataset of 4791 manually labeled alarm episodes extracted from 108 neurosurgical patients. The comparative analysis provided between spectral regression, kernel spectral regression, and support vector machines indicates the significant improvement of the proposed framework in detecting false ICP alarms in comparison to a threshold-based technique that is conventionally used. Another contribution of this work is to exploit an adaptive discretization to reduce the dimensionality of the input features. The resulting features lead to a decrease of 30% of false ICP alarms without compromising sensitivity.

  20. Analysis of intracranial pressure: past, present, and future.

    Science.gov (United States)

    Di Ieva, Antonio; Schmitz, Erika M; Cusimano, Michael D

    2013-12-01

    The monitoring of intracranial pressure (ICP) is an important tool in medicine for its ability to portray the brain's compliance status. The bedside monitor displays the ICP waveform and intermittent mean values to guide physicians in the management of patients, particularly those having sustained a traumatic brain injury. Researchers in the fields of engineering and physics have investigated various mathematical analysis techniques applicable to the waveform in order to extract additional diagnostic and prognostic information, although they largely remain limited to research applications. The purpose of this review is to present the current techniques used to monitor and interpret ICP and explore the potential of using advanced mathematical techniques to provide information about system perturbations from states of homeostasis. We discuss the limits of each proposed technique and we propose that nonlinear analysis could be a reliable approach to describe ICP signals over time, with the fractal dimension as a potential predictive clinically meaningful biomarker. Our goal is to stimulate translational research that can move modern analysis of ICP using these techniques into widespread practical use, and to investigate to the clinical utility of a tool capable of simplifying multiple variables obtained from various sensors.

  1. Severe head injuries and intracranial pressure monitoring outcome in Southern Iran

    Directory of Open Access Journals (Sweden)

    Majid Reza Farrokhi

    2006-11-01

    Full Text Available BACKGROUND: Head injury is still a major cause of death and disability. Despite advances in intensive monitoring and clinical practice, little data is available to show the predictive value of intracranial pressure monitoring in assessment of the outcome of head injuries. This study was undertaken to evaluate this predictive value and is the first Iranian study in which ICP monitoring has been included. METHODS: In a prospective study from September 1999 to September 2003, all head- injured patients (53 patients with GCS of 4-8 who were admitted to Nemazee Hospital of Shiraz University of Medical Sciences were included in this study. Subarachnoid screw method or ventricular catheter via ventriculostomy was used to determine intracranial pressure. Patients were monitored for 3 days and were followed for two years at 6-month intervals. RESULTS: Car accidents were the most common cause of head injury (43.3% and 43.3% of patients had GCS of 8. Sixty percent of patients had abnormal intracranial pressure. The patients were most commonly in their first decade of life (18.8% and 81% of patients were male. Controlling increased intracranial pressure was successful in 60% of patients and resulted in a decrease of mortality rate from 60% to 15%. CONCLUSIONS: Early treatment of increased intracranial pressure in head injury patients would be beneficial in reducing mortality and morbidity rates. KEY WORDS: Southern Iran, head injury, outcome, intracranial pressure.

  2. Comparison of the sagittal sinus cross-sectional area between patients with multiple sclerosis, hydrocephalus, intracranial hypertension and spontaneous intracranial hypotension: a surrogate marker of venous transmural pressure?

    Science.gov (United States)

    Bateman, Grant A; Lechner-Scott, Jeannette; Copping, Ross; Moeskops, Christopher; Yap, Swee Leong

    2017-07-06

    There is evidence that patients with multiple sclerosis (MS) and hydrocephalus share some common pathophysiological mechanisms. Alterations in CSF pressure are known to affect cerebral venous sinus geometry. To further explore these mechanisms, we measured the superior sagittal sinus (SSS) cross-sectional area 3 cm above the torcular using T2 images in 20 MS, 10 spontaneous intracranial hypotension (SIH), 21 hydrocephalus and 20 idiopathic intracranial hypertension (IIH) patients and compared with 20 matched controls. The SSS area was reduced by 25% in hydrocephalus (p = 0.0008), increased by 22% (p = 0.037) in SIH and unchanged in IIH compared to matched controls. In MS there was a 16% increase in SSS area (p = 0.01).The findings suggest that changes in SSS cross-sectional are common between MS and SIH patients, while in hydrocephalus and IIH these are different.

  3. Zero drift of intraventricular and subdural intracranial pressure monitoring systems

    Institute of Scientific and Technical Information of China (English)

    CHEN Li; DU Hang-gen; YIN Li-chun; HE Min; ZHANG Guo-jun; TIAN Yong; WANG Cheng

    2013-01-01

    Objective:To assess zero drift of intraventricular and subdural intracranial pressure (ICP) monitoring systems.Methods:A prospective study was conducted in patients who received Codman ICP monitoring in the neurosurgical department from January 2010 to December 2011.According to the location of sensors,the patients were categorized into two groups:intraventricular group and subdural group.Zero drift between the two groups and its association with the duration of ICP monitor were analyzed.Results:Totally,22 patients undergoing intraventricular ICP monitoring and 27 receiving subdural ICP monitoring were enrolled.There was no significant difference in duration of ICP monitoring,zero drift value and its absolute value between intraventricular and subdural groups (5.38 d±2.58 d vs 4.58 d±2.24d,0.77 mmHg±2.18 mm Hg vs 1.03 mmHg±2.06mmHg,1.68 mmHg±155 mmHg vs 1.70mmHg±153 mmHg,respectively; all P>0.05).Absolute value of zero drift in both groups significantly rose with the increased duration of ICP monitoring (P<0.05) while zero drift value did not.Moreover,daily absolute value in the intraventricular group was significantly smaller than that in the subdural group (0.27 mm Hg±0.32 mm Hg vs 0.29 mm Hg±0.18 mm Hg,P<0.05).Conclusion:This study demonstrates that absolute value of zero drift significantly correlates with duration of both intraventricular and subdural ICP monitoring.Due to the smaller daily absolute value,ICP values recorded from intraventricular system may be more reliable than those from subdural system.

  4. Intracranial pressure monitoring for special patterns of frontal lobe contusions

    Institute of Scientific and Technical Information of China (English)

    DONG Ji-rong; CAI Xue-jian; WANG Biao; WANG Yu-hai; SHI Zhong-hua; LIU Bing; CAI Sang; XU Qin-yi

    2010-01-01

    Objective:To study the effect and indications of intracranial pressure(ICP)monitoring for frontal lobe contusion patients.Methods:During January 2005-December 2008,34 cases of frontal lobe contusion received ICP monitoring in our department(monitoring group).Different treatment protocols were adopted according to the results of ICP.Meanwhile 46 cases of same type of head-injured patients who did not undergo ICP monitoring served as control group.Results:We found that ICP elevated dramatically within 24 hours after head injury if the contusions were located in frontal longitudinal dehiscence,bilateral undersurface of frontal lobe or dispersed in bilateral lobe.After half a year follow-up and on the basis of Glasgow Coma Scale assessment,the monitoring group showed better outcome than the control group with good recovery in 24 cases(70.6%),moderate disability in 7 cases(20.6%),severe disability in 2(5.88%)and death in 1(2.94%).The outcome of control group displayed good condition in 25 cases(54.3%),moderate disabilities in 8(17.4%),severe disability in 7(15.2%),and death in 6(13.0%).Conclusions:Frontal lobe contusions are vulnerable and complex head injuries,especially when the contusions are located in frontal longitudinal dehiscence,bilateral undersurface of frontal lobe or diffused in bilateral lobes.These patients should undergo ICP monitoring regardless of their consciousness status.If ICP elevates over 25 mm Hg,the craniotomy is mandatory and will markedly reduce the mortality and disability of these patients.

  5. Cerebrospinal Fluid Corticosteroid Levels and Cortisol Metabolism in Patients with Idiopathic Intracranial Hypertension : A Link between 11 beta-HSD1 and Intracranial Pressure Regulation?

    NARCIS (Netherlands)

    Sinclair, Alexandra J.; Walker, Elizabeth A.; Burdon, Michael A.; van Beek, Andre P.; Kema, Ido P.; Hughes, Beverly A.; Murray, Philip I.; Nightingale, Peter G.; Stewart, Paul M.; Rauz, Saaeha; Tomlinson, Jeremy W.

    2010-01-01

    Context: The etiology of idiopathic intracranial hypertension (IIH) is unknown. We hypothesized that obesity and elevated intracranial pressure may be linked through increased 11 beta-hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) activity. Objective: The aim was to characterize 11 beta-HSD1 in

  6. Intracranial Pressure Monitoring: Relationship Between Indices of Cerebrovascular Reserve, System Bandwidth, and Cerebral Perfusion

    Science.gov (United States)

    2007-11-02

    reactivity index ( PrX ), derived from correlation of the dynamic features of the intracranial pressure (ICP) and arterial blood pressure (ABP...brain has lost the ability to regulate blood flow, these pressure signals are similar [1,2]. The PrX index is numerically derived from the correlation

  7. Changes in intracranial pressure after calvarial expansion surgery in children with slit ventricle syndrome.

    Science.gov (United States)

    Eide, P K; Helseth, E; Due-Tønnessen, B; Lundar, T

    2001-10-01

    The effect of calvarial expansion on symptom relief and intracranial pressure (ICP) in three children with slit ventricle syndrome (SVS) and intracranial hypertension despite a functioning ventricular shunt is reported. These children presented with a clinical picture of SVS, accompanied by slit-like ventricles on cranial computer tomography scan and intracranial hypertension. Calvarial expansion was performed by mans of an anterior approach in one case and a posterior approach (modified tiara plastic) in the other two cases. After calvarial expansion, symptoms of intracranial hypertension were abolished in one case and markedly reduced in two cases (observation period 25-36 months). Comparison of ICP before and after surgery was performed by means of new software (Sensometrics Pressure Analyser, version 1.2) that revealed a significant reduction in the number of abnormal ICP elevations after surgery. The results were not accompanied by changes in the size of the cerebral ventricles. This study demonstrates that in children with SVS and intracranial hypertension despite a functioning shunt, calvarial expansion may reduce ICP and produce long-lasting symptom relief. In these cases, we suggest that intracranial hypertension was caused by compromised intracranial volume. Copyright 2001 S. Karger AG, Basel

  8. Unsteady velocity measurements in a realistic intracranial aneurysm model

    Science.gov (United States)

    Ugron, Ádám; Farinas, Marie-Isabelle; Kiss, László; Paál, György

    2012-01-01

    The initiation, growth and rupture of intracranial aneurysms are intensively studied by computational fluid dynamics. To gain confidence in the results of numerical simulations, validation of the results is necessary. To this end the unsteady flow was measured in a silicone phantom of a realistic intracranial aneurysm. A flow circuit was built with a novel unsteady flow rate generating method, used to model the idealised shape of the heartbeat. This allowed the measurement of the complex three-dimensional velocity distribution by means of laser-optical methods such as laser doppler anemometry (LDA) and particle image velocimetry (PIV). The PIV measurements, available with high temporal and spatial distribution, were found to have good agreement with the control LDA measurements. Furthermore, excellent agreement was found with the numerical results.

  9. Blood pressure measurement

    Science.gov (United States)

    Diastolic blood pressure; Systolic blood pressure; Blood pressure reading; Measuring blood pressure ... or your health care provider will wrap the blood pressure cuff snugly around your upper arm. The lower ...

  10. CT changes in children with drained hydrocephalus and intermittently raised intracranial pressure

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, H.; Korinthenberg, R.; Erlemann, R.; Lengerke, H.J. von

    1987-10-01

    Seven children with drained hydrocephalus are described who showed increasingly severe and frequent episodes of intermittently raised intracranial pressure. CT examinations during symptom-free intervals, or after conservative treatment, showed collapsed slit-like ventricles. Examination during attacks of raised pressure showed relative dilatation of the ventricles as compared with earlier examinations. Children with ventricular shunts of long duration may develop a shunt-dependent syndrome; CT may show normal or narrow ventricles and this does not exclude the possibility of a rise of intracranial pressure. These findings may help in making the diagnosis by means of CT without any further invasive procedure.

  11. Are Medications Involved in Vision and Intracranial Pressure Changes Seen in Spaceflight?

    Science.gov (United States)

    Wotring, V. E.

    2016-01-01

    It has recently been reported that intracranial pressure (ICP) and/or vision changes, have occurred in a number of long duration astronauts. Some crewmembers have experienced changes in their vision after long-duration spaceflight on the ISS. These impairments include visual performance decrements, development of cotton-wool spots or choroidal folds, optic-disc edema, optic nerve sheath distention, and/or posterior globe flattening with varying degrees of severity and permanence. These changes are now used to define the visual impairment/intracranial pressure (VIIP) syndrome. The reasons for these potentially debilitating medical issues are currently unknown. The potential role of administered medications has not yet been examined, but it is known that many medications can have side effects that are similar to VIIP symptoms. Some medications raise blood pressure, which can affect intracranial pressure. Many medications that act in the central nervous system can affect intracranial pressures and/or vision. About 40% of the medications in the ISS kit are known to cause side effects involving changes in blood pressure, intracranial pressure and/or vision. For this reason, we proposed an investigation of the potential relationship between ISS medications and their risk of causing or exacerbating VIIP-like symptoms. The purpose of this study was to use medication usage records for affected and unaffected crew to determine if use of particular medications seemed to correlate with VIIP occurrence or severity. Due to the limited amount of data available from crewmembers, we added a large terrestrial data set to this study. Using publically available FDA Adverse Event Reports (FDA AERs) from many medications and medication classes, we identified increased reports of vision or intracranial pressure changes in several medication categories, which are presumed to be the most likely medications that could be involved in VIIP occurrence or severity.

  12. Intracranial and Intraocular Pressure During Various Degrees of Head-Down Tilt.

    Science.gov (United States)

    Marshall-Goebel, Karina; Mulder, Edwin; Bershad, Eric; Laing, Charles; Eklund, Anders; Malm, Jan; Stern, Claudia; Rittweger, Jörn

    2017-01-01

    More than half of astronauts develop ophthalmic changes during long-duration spaceflight consistent with an abnormal intraocular and intracranial pressure (IOP, ICP) difference. The aim of our study was to assess IOP and ICP during head-down tilt (HDT) and the additive or attenuating effects of 1% CO2 and lower body negative pressure (LBNP). In Experiment I, IOP and ICP were measured in nine healthy subjects after 3.5 h HDT in five conditions: -6°, -12°, and -18° HDT, -12° with 1% CO2, and -12° with -20 mmHg LBNP. In Experiment II, IOP was measured in 16 healthy subjects after 5 min tilt at +12°, 0°, -6°, -12°, -18°, and -24°, with and without -40 mmHg LBNP. ICP was only found to increase from supine baseline during -18° HDT (9.2 ± 0.9 and 14.4 ± 1 mmHg, respectively), whereas IOP increased from 15.7 ± 0.3 mmHg at 0° to 17.9 ± 0.4 mmHg during -12° HDT and from 15.3 ± 0.4 mmHg at 0° to 18.7 ± 0.4 mmHg during -18° HDT. The addition of -20 mmHg LBNP or 1% CO2 had no further effects on ICP or IOP. However, the use of -40 mmHg LBNP during HDT lowered IOP back to baseline values, except at -24° HDT. A small, posterior intraocular-intracranial pressure difference (IOP > ICP) is maintained during HDT, and a sustained or further decreased difference may lead to structural changes in the eye in real and simulated microgravity.Marshall-Goebel K, Mulder E, Bershad E, Laing C, Eklund A, Malm J, Stern C, Rittweger J. Intracranial and intraocular pressure during various degrees of head-down tilt. Aerosp Med Hum Perform. 2017; 88(1):10-16.

  13. Ultrasound as a Noninvasive Method to Assess Changes of Intracranial Volume and Pressure During Simulated Microgravity

    Science.gov (United States)

    Murthy, G.; Yost, W. T.; Ballard, R. E.; Watenpaugh, D. E.; Kawai, Y.; Hargens, A. R.

    1994-01-01

    Headaches are commonly experienced by astronauts in microgravity and by subjects undergoing head-down tilt (simulated microgravity on Earth). Exposure to microgravity probably elevates blood pressure and flow in the head which may increase intracranial volume (ICV) and pressure (ICP) and in turn cause headache. Due to the slightly compliant nature of the cranial vault and the encasement of brain and its vasculature within this vault, any increase of ICV will increase ICP and slightly distend the cranium. Previous studies document perivascular edema and increased ICP in rhesus monkeys during head-down tilt. Elevated ICP has also been reported in humans during head-down tilt. ICP measurements in healthy humans are rare because of the invasiveness of currently-available measurement techniques. Therefore, we proposed a noninvasive ultrasound technique to assess changes of ICV and JCP. The ultrasound principle is based on compliance of the cranial vault. A 450 kHz ultrasound stimulus is transmitted through the cranium by a transducer every 7.5-10 msec. The ultrasound wave enters the brain tissue, reflects off the opposite side of the cranium and is received by the same transducer. The detected wave is compared for phase quadrature (90 deg.to transmitted wave). Because the electronic circuitry of the device maintains a 90 deg. phase (phi), any alterations in the detected wave caused by an increase of ICV and ICP will be reflected as a change in the wave frequency. Phase shift is directly proportional to path length of the wave, DELTA x, which is expressed as DELTA x = phi lambda/2 pi where lambda is wavelength. Elevated ICV and ICP expand the cranial vault and increase path length of the wave (a measure of intracranial distance). Increased path length equals reduced frequency of the detected wave. Reduced frequency is then related to elevated ICP. This technique has potential uses for ICP studies of astronauts in space and head trauma patients on Earth.

  14. Are Medications Involved in Vision and intracranial Pressure Changes Seen in Spaceflight?

    Science.gov (United States)

    Wotring, V. E.

    2016-01-01

    Some crewmembers have experienced changes in their vision after long-duration spaceflight on the ISS. These impairments include visual performance decrements, development of cotton-wool spots or choroidal folds, optic-disc edema, optic nerve sheath distention, and/or posterior globe flattening with varying degrees of severity and permanence. These changes are now used to define the visual impairment/intracranial pressure (VIIP) syndrome. The reasons for these potentially debilitating medical issues are currently unknown. The potential role of administered medications has not yet been examined, but it is known that many medications can have side effects that are similar to VIIP symptoms. Some medications raise blood pressure, which can affect intracranial pressure. Many medications that act in the central nervous system can affect intracranial pressures and/or vision. About 40% of the medications in the ISS kit are known to cause side effects involving changes in blood pressure, intracranial pressure and/or vision. For this reason, we proposed an investigation of the potential relationship between ISS medications and their risk of causing or exacerbating VIIP-like symptoms. The purpose of this study was to use medication usage records for affected and unaffected crew to determine if use of particular medications seemed to correlate with VIIP occurrence or severity.

  15. A new method and software for quantitative analysis of continuous intracranial pressure recordings.

    Science.gov (United States)

    Eide, P K; Fremming, A D

    2001-12-01

    A computer software utilising a new method for quantitative analysis of intracranial pressure (ICP), was developed to provide a more accurate analysis of continuously recorded ICP. Intracranial pressure curves were analysed by the software to explore the relationship between mean ICP and the presence of ICP elevations. The Sensometrics Pressure Analyser (version 1.2) software provides a quantitative analysis of the ICP curve, presenting the ICP recordings as a matrix of numbers of ICP elevations of different levels (e.g. 20 or 30 or 40 mmHg) and durations (e.g. 0.5, 5 or 10 minutes). The number of ICP elevations may be standardised by calculating the number of elevations during for instance a 10 hour period. The computer software was used to retrospectively analyse the ICP curves in our first consecutive 127 patients undergoing continuous 24 hours ICP monitoring during the two-year period from February 1997 to December 1998. The indications for ICP monitoring were suspected hydrocephalus, craniosynostosis or shunt failure. Analysis of the ICP curves revealed a rather weak relationship between mean ICP and the number of apparently abnormal ICP elevations (that is elevations of 20 mmHg or above). Abnormal ICP elevations were present in a relatively high proportion of cases with a normal mean ICP below 10 mmHg, or a borderline mean ICP between 10 and 15 mmHg. In addition, the ICP data of two cases are presented suggesting that mean ICP may be an inaccurate measure of ICP. The results of analysing ICP curves by means of this method and software reveal that calculation of ICP elevations of different levels and durations may represent a more accurate description of the ICP curve than calculation of mean ICP. The method may enhance the clinical application of ICP monitoring.

  16. Increased intracranial pressure in mini-pigs exposed to simulated solar particle event radiation

    Science.gov (United States)

    Sanzari, JK; Muehlmatt, A; Savage, A; Lin, L; Kennedy, AR

    2014-01-01

    Changes in intracranial pressure (ICP) during space flight have stimulated an area of research in space medicine. It is widely speculated that elevations in ICP contribute to structural and functional ocular changes, including deterioration in vision, which is also observed during space flight. The aim of this study was to investigate changes in OP occurring as a result of ionizing radiation exposure (at doses and dose-rates relevant to solar particle event radiation). We used a large animal model, the Yucatan mini-pig, and were able to obtain measurements over a 90 day period. This is the first investigation to show long term recordings of ICP in a large animal model without an invasive craniotomy procedure. Further, this is the first investigation reporting increased ICP after radiation exposure. PMID:25242832

  17. The effect of furosemide on intracranial pressure and hemorrhage in preterm rabbits.

    Science.gov (United States)

    Lorenzo, A V; Greene, C S; Hornig, G W; Zavala, L M; Welch, K

    1989-05-01

    The hypothesis that intracranial hypotension due to excessive postnatal fluid loss places the premature infant at risk for germinal matrix and intraventricular hemorrhage (GM-IVH) was tested in preterm rabbits delivered at 28 and 29 days of gestation (term 32 days). Furosemide administered to newborn pups induced a diuresis that resulted in a 11% to 22% loss in body weight and a concomitant decline in muscle water (13% to 16%) and sodium (18% to 21%). Paradoxically, no change occurred in the water or electrolyte content of the brain even though cerebrospinal fluid and brain tissue pressure, but not blood pressure, declined. These changes were absent in littermates treated with saline. Microscopic examination of brain sections revealed a greater incidence of intracranial hemorrhage, particularly in the germinal matrix and choroid plexus, in furosemide-treated than in saline-treated preterm rabbit pups. These results are consistent with the hypothesis that intracranial hypotension promotes the incidence of GH-IVH in preterm animals.

  18. Modified big bone valve decompression reduces intracranial pressure and improves prognosis following craniocerebral injury

    Institute of Scientific and Technical Information of China (English)

    Xinzhong Wen; Leiming Huo

    2007-01-01

    of incision, which was for loosing the tension of scalp and sewing it. ②In the conventional operation group, standard big bone valve decompression was performed in all the patients, and intracranial pressure was monitored. At postoperative 3, 5, 7 and 15 days, intracranial pressure of patients in two groups was measured. Meanwhile, prognosis of patients in two groups were compared and analyzed. MAIN OUTCOME MEASURES: Comparison of intracranial pressure and prognosis of patients between two groups at postoperative different time points.RESULTS: Eighty-eight involved patients with craniocerebral injury participated in the final analysis. ①At postoperative 3, 5, 7 and 15 days, intracranial pressure of patients in the modified operation group was (2.39±0.53), (2.13±0.53), (1.86±0.53) kPa, which was significantly lower than that in the conventional operation group [ (2.66±0.53), (2.39±0.66), (2.13±0.53) kPa, P < 0.01]. ②In the conventional operation group, 8 (17%) patients died, 3 (6%) patients presented vegetative state, which was respectively less than that in the conventional operation group [4 (10%) and 3(6%), P < 0.01]; In the conventional operation group, 6(13%) and 3(6%) patients suffered from moderate and severe disability, respectively, which was significantly less than that in the conventional operation group [4 (10%) ,5 (12%) ,P<0.01], 12(26%) and 16 (35%) patients suffered from mild disability and turned better, respectively, which was more than that in the conventional operation group [6 (15%), 13 (32%), P < 0.01].CONCLUSION: Modified big bone valve decompression fundamentally changes from conventional big bone valve decompression. It fully decompresses and improves prognosis of patients.

  19. The tympanic membrane displacement analyser for monitoring intracranial pressure in children.

    Science.gov (United States)

    Gwer, Samson; Sheward, Victoria; Birch, Anthony; Marchbanks, Robert; Idro, Richard; Newton, Charles R; Kirkham, Fenella J; Lin, Jean-Pierre; Lim, Ming

    2013-06-01

    Raised intracranial pressure (ICP) is a potentially treatable cause of morbidity and mortality but tools for monitoring are invasive. We sought to investigate the utility of the tympanic membrane displacement (TMD) analyser for non-invasive measurement of ICP in children. We made TMD observations on normal and acutely comatose children presenting to Kilifi District Hospital (KDH) at the rural coast of Kenya and on children on follow-up for idiopathic intracranial hypertension at Evelina Children's Hospital (ECH), in London, UK. We recruited 63 patients (median age 3.3 (inter-quartile range (IQR) 2.0-4.3) years) at KDH and 14 children (median age 10 (IQR 5-11) years) at ECH. We observed significantly higher (more negative) TMD measurements in KDH children presenting with coma compared to normal children seen at the hospital's outpatient department, in both semi-recumbent [mean -61.3 (95 % confidence interval (95 % CI) -93.5 to 29.1) nl versus mean -7.1 (95 % CI -54.0 to 68.3) nl, respectively; P = 0.03] and recumbent postures [mean -61.4 (95 % CI -93.4 to -29.3) nl, n = 59) versus mean -25.9 (95 % CI -71.4 to 123.2) nl, respectively; P = 0.03]. We also observed higher TMD measurements in ECH children with raised ICP measurements, as indicated by lumbar puncture manometry, compared to those with normal ICP, in both semi-recumbent [mean -259.3 (95 % CI -363.8 to -154.8) nl versus mean 26.7 (95 % CI -52.3 to 105.7) nl, respectively; P analyser has a potential utility in monitoring ICP in a variety of clinical circumstances.

  20. Contralateral Hypoplastic Venous Draining Sinuses Are Associated with Elevated Intracranial Pressure in Unilateral Cerebral Sinovenous Thrombosis.

    Science.gov (United States)

    Farias-Moeller, R; Avery, R; Diab, Y; Carpenter, J; Murnick, J

    2016-12-01

    Variations in cerebral venous development can influence the ability to regulate drainage. In cerebral sinovenous thrombosis, these variations can be associated with elevated intracranial pressure. We present a series of pediatric patients with unilateral cerebral sinovenous thrombosis and investigate whether the contralateral venous sinus size increases the risk of developing elevated intracranial pressure. Patients diagnosed with a unilateral cerebral sinovenous thrombosis were identified by querying our institutional radiology data base. The difference in the occurrence of elevated intracranial pressure in patients with cerebral sinovenous thrombosis with and without hypoplastic venous sinuses was studied. Twelve cases of unilateral cerebral sinovenous thrombosis met the inclusion criteria and had sufficient images. Six patients had hypoplastic contralateral venous sinuses. The presence of hypoplastic contralateral venous sinus in the setting of thrombosis of a dominant sinus was associated with elevation of intracranial pressure (83% versus 0%, P = .015). Patients with cerebral sinovenous thrombosis and contralateral hypoplastic venous sinuses are at higher risk of developing elevated ICP and may benefit from screening with an ophthalmologic examination.

  1. Detection of intracochlear and intracranial pressure changes with otoacoustic emissions : a gerbil model

    NARCIS (Netherlands)

    Buki, B; de Kleine, E; Wit, HP; Avan, P

    Increased intracranial pressure (ICP) is known to affect the phases and levels of lower-frequency distortion-product otoacoustic emissions (DPOAE) in a characteristic: manner suggestive of an increase in the stiffness of the stapes system. likely in relation to an attendant increased intracochlear

  2. Detection of intracochlear and intracranial pressure changes with otoacoustic emissions : a gerbil model

    NARCIS (Netherlands)

    Buki, B; de Kleine, E; Wit, HP; Avan, P

    2002-01-01

    Increased intracranial pressure (ICP) is known to affect the phases and levels of lower-frequency distortion-product otoacoustic emissions (DPOAE) in a characteristic: manner suggestive of an increase in the stiffness of the stapes system. likely in relation to an attendant increased intracochlear p

  3. Visual Impairment/Intracranial Pressure Research Clinical Advisory Panel (RCAP) Meeting. [Summary Report

    Science.gov (United States)

    Villarreal, Jennifer

    2014-01-01

    The Visual Impairment/Intracranial Pressure (VIIP) Research and Clinical Advisory Panel convened on December 1, 2014 at the ISS Conference Facility in Houston. The panel members were provided updates to the current clinical cases and treatment plans along with the latest research activities (http://humanresearchroadmap.nasa.gov/Risks/?i=105) and preliminary study results. The following is a summary of this meeting.

  4. Refractory High Intracranial Pressure following Intraventricular Hemorrhage due to Moyamoya Disease in a Pregnant Caucasian Woman

    Science.gov (United States)

    Montiel, Virginie; Grandin, Cécile; Goffette, Pierre; Fomekong, Edward; Hantson, Philippe

    2009-01-01

    Intraventricular hemorrhage during pregnancy is usually followed by a poor recovery. When caused by moyamoya disease, ischemic or hemorrhagic episodes may complicate the management of high intracranial pressure. A 26-year-old Caucasian woman presented with generalized seizures and a Glasgow Coma Score (GCS) of 3 during the 36th week of pregnancy. The fetus was delivered by caesarean section. The brain CT in the mother revealed bilateral intraventricular hemorrhage, a callosal hematoma, hydrocephalus and right frontal ischemia. Refractory high intracranial pressure developed and required bilateral ventricular drainage and intensive care treatment with barbiturates and hypothermia. Magnetic resonance imaging and cerebral angiography revealed a moyamoya syndrome with rupture of the abnormal collateral vascular network as the cause of the hemorrhage. Intracranial pressure could only be controlled after the surgical removal of the clots after a large opening of the right ventricle. Despite an initially low GCS, this patient made a good functional recovery at one year follow-up. Management of refractory high intracranial pressure following moyamoya related intraventricular bleeding should require optimal removal of ventricular clots and appropriate control of cerebral hemodynamics to avoid ischemic or hemorrhagic complications. PMID:20508823

  5. Refractory High Intracranial Pressure following Intraventricular Hemorrhage due to Moyamoya Disease in a Pregnant Caucasian Woman

    Directory of Open Access Journals (Sweden)

    Virginie Montiel

    2009-02-01

    Full Text Available Intraventricular hemorrhage during pregnancy is usually followed by a poor recovery. When caused by moyamoya disease, ischemic or hemorrhagic episodes may complicate the management of high intracranial pressure. A 26-year-old Caucasian woman presented with generalized seizures and a Glasgow Coma Score (GCS of 3 during the 36th week of pregnancy. The fetus was delivered by caesarean section. The brain CT in the mother revealed bilateral intraventricular hemorrhage, a callosal hematoma, hydrocephalus and right frontal ischemia. Refractory high intracranial pressure developed and required bilateral ventricular drainage and intensive care treatment with barbiturates and hypothermia. Magnetic resonance imaging and cerebral angiography revealed a moyamoya syndrome with rupture of the abnormal collateral vascular network as the cause of the hemorrhage. Intracranial pressure could only be controlled after the surgical removal of the clots after a large opening of the right ventricle. Despite an initially low GCS, this patient made a good functional recovery at one year follow-up. Management of refractory high intracranial pressure following moyamoya related intraventricular bleeding should require optimal removal of ventricular clots and appropriate control of cerebral hemodynamics to avoid ischemic or hemorrhagic complications.

  6. Management of Raised Intracranial Pressure in Head Injury

    African Journals Online (AJOL)

    nial pressure (ICP) the control and course of which have a critical bearing on morbidity ... In the extradural monitoring, which is exemplified by the. Ladd equipment, the .... es blood urea nitrogen and arterial blood pressure. Glyurol a trivalent ...

  7. Management of raised intracranial pressure in children with traumatic brain injury

    OpenAIRE

    Vinay Kukreti; Hadi Mohseni-Bod; James Drake

    2014-01-01

    Increased intracranial pressure (ICP) is associated with worse outcome after traumatic brain injury (TBI). The current guidelines and management strategies are aimed at maintaining adequate cerebral perfusion pressure and treating elevated ICP. Despite controversies, ICP monitoring is important particularly after severe TBI to guide treatment and in developed countries is accepted as a standard of care. We provide a narrative review of the recent evidence for the use of ICP monitoring and man...

  8. Relationship between hyperventilation and intracranial pressure in patients with severe head injury

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@With high fatality rate and disability rate, the pathophysiologic changes of severe head injury are complicated. But the method of lowering intracranial pressure (ICP) through artificial hyperventilation is called in question recently. To understand the related changes of the partial pressure of carbon dioxide in artery (PaCO2) and the ICP at the acute period of severe head injury, a total of 64 patients with severe head injury were monitored and analyzed on the 3rd day after injury.

  9. Intracranial pressure and cerebral perfusion pressure monitoring in non-TBI patients: special considerations.

    Science.gov (United States)

    Helbok, Raimund; Olson, DaiWai M; Le Roux, Peter D; Vespa, Paul

    2014-12-01

    The effect of intracranial pressure (ICP) and the role of ICP monitoring are best studied in traumatic brain injury (TBI). However, a variety of acute neurologic illnesses e.g., subarachnoid hemorrhage, intracerebral hemorrhage, ischemic stroke, meningitis/encephalitis, and select metabolic disorders, e.g., liver failure and malignant, brain tumors can affect ICP. The purpose of this paper is to review the literature about ICP monitoring in conditions other than TBI and to provide recommendations how the technique may be used in patient management. A PubMed search between 1980 and September 2013 identified 989 articles; 225 of which were reviewed in detail. The technique used to monitor ICP in non-TBI conditions is similar to that used in TBI; however, indications for ICP monitoring often are intertwined with the presence of obstructive hydrocephalus and hence the use of ventricular catheters is more frequent. Increased ICP can adversely affect outcome, particularly when it fails to respond to treatment. However, patients with elevated ICP can still have favorable outcomes. Although the influence of ICP-based care on outcome in non-TBI conditions appears less robust than in TBI, monitoring ICP and cerebral perfusion pressure can play a role in guiding therapy in select patients.

  10. [Noninvasive determination of pressure relations of intracranial and intracochlear fluid spaces during the glycerol test in normal probands and patients with Menière's disease].

    Science.gov (United States)

    Gosepath, K; Maurer, J; Thews, O; Mann, W

    1996-07-01

    The cochlear aqueduct is a route for direct pressure transfer between intracranial and intracochlear fluids. In patients with Menière's disease, intracochlear pressure is presumably disturbed. The "Tympanic Membrane Displacement Analyser (TDA)" is a new system which provides a useful noninvasive method of detecting intracranial and intracochlear pressure changes. In this study TDA measurements in combination with a glycerol test were performed in nine patients with Menière's disease and in seven normal persons. Before ingestion of glycerol, no significant difference in pressure was found between the two groups. After ingestion of glycerol a temporary decrease in intracochlear pressure was detected in both groups without any significant difference between the two groups. These results show that the combination of glycerol testing and TDA measurements does not seem to be helpful for the differential diagnosis of Menière's disease.

  11. The Camino intracranial pressure sensor: is it optimal technology? An internal audit with a review of current intracranial pressure monitoring technologies.

    Science.gov (United States)

    Piper, I; Barnes, A; Smith, D; Dunn, L

    2001-11-01

    To audit the reliability of the Camino intracranial pressure (ICP) sensor (Camino Laboratories, San Diego, CA) in our clinical practice as part of a continuing quality assurance program, and to assess its relative usefulness as compared with currently available ICP monitoring technologies that we reviewed. Prospective audit of ICP device reliability and function in 50 patients with head injuries. Zero drift was recorded immediately after the ICP device was removed from the patient. Dynamic frequency response bench testing of each functioning catheter from 0 to 30 Hz and static calibration testing from 0 to 100 mmHg during environmental temperature variation from 22 to 40 degrees C were carried out. Zero drift (range, -13 to 22 mmHg; median, -1 mmHg) was recorded immediately after the devices were removed from patients. Seventeen (50%) of the devices tested for zero drift had absolute drifts of at least 3 mmHg. There was no correlation between recorded zero drift and duration of monitoring (r = 0.154, P = 0.207). Five sensors (10% of those tested) failed during patient monitoring and were replaced. Static and dynamic calibration tests of the functioning sensors were within the manufacturer's specifications. However, the sensitivity of the devices to environmental temperature remains a problem. The Camino ICP sensor remains one of the most popular ICP monitoring devices for use in patients with traumatic brain injuries. However, our recent in-house assessment demonstrated the robustness of the device to be less than adequate during routine practice. In this study, more than 50% exhibited zero drift greater than 3 mmHg, which is unacceptable in a catheter tip ICP monitoring device in which zero drift and calibration cannot be checked in vivo. A review of the literature revealed that other available ICP monitoring devices may prove to be more reliable and thus more appropriate for routine clinical measurement of ICP.

  12. Cardiopulmonary and intracranial pressure changes related to endotracheal suctioning in preterm infants.

    Science.gov (United States)

    Durand, M; Sangha, B; Cabal, L A; Hoppenbrouwers, T; Hodgman, J E

    1989-06-01

    Although endotracheal (ET) suctioning is performed frequently in sick newborn infants, its effects on cardiorespiratory variables and intracranial pressure (ICP) have not been thoroughly documented in neonates greater than 24 h who were not paralyzed while receiving mechanical ventilation. This study evaluates these changes in preterm infants who required ventilatory assistance. We measured transcutaneous PO2 and PCO2 (PtcO2 and PtcCO2, respectively), intra-arterial BP, heart rate, ICP, and cerebral perfusion pressure (CPP) before, during, and for at least 5 min after ET suctioning in 15 low birth weight infants less than 1500 g and less than or equal to 30 days of age. One infant was studied twice. A suction adaptor was used to avoid disconnecting the patient from the ventilator and to attempt to minimize hypoxemia and hypercapnia during suctioning. The patients were studied in the supine position and muscle relaxants were not used. PtcO2 decreased 12.1% while PtcCO2 increased 4.7% 1 min after suctioning; however, greater increases in mean BP (33%) and ICP (117%) were observed during suctioning. CPP also increased during the procedure. ICP returned to baseline almost immediately, whereas BP remained slightly elevated 1 min after suctioning. Our findings demonstrate that ET suctioning significantly increases BP, ICP, and CPP in preterm infants on assisted ventilation in the first month of life. These changes appear to be independent of changes observed in oxygenation and ventilation.

  13. Miniature Coplanar Implantable Antenna on Thin and Flexible Platform for Fully Wireless Intracranial Pressure Monitoring System

    Directory of Open Access Journals (Sweden)

    M. Waqas A. Khan

    2017-01-01

    Full Text Available Minimally invasive approach to intracranial pressure monitoring is desired for long-term diagnostics. The monitored pressure is transmitted outside the skull through an implant antenna. We present a new miniature (6 mm × 5 mm coplanar implant antenna and its integration on a sensor platform to establish a far-field data link for the sensor readout at distances of 0.5 to 1 meter. The implant antenna was developed using full-wave electromagnetic simulator and measured in a liquid phantom mimicking the dielectric properties of the human head. It achieved impedance reflection coefficient better than −10 dB from 2.38 GHz to 2.54 GHz which covers the targeted industrial, scientific, and medical band. Experiments resulted in an acceptable peak gain of approximately −23 dBi. The implant antenna was submerged in the liquid phantom and interfaced to a 0.5 mW voltage controlled oscillator. To verify the implant antenna performance as a part of the ICP monitoring system, we recorded the radiated signal strength using a spectrum analyzer. Using a half-wavelength dipole as the receiving antenna, we captured approximately −58.7 dBm signal at a distance of 1 m from the implant antenna which is well above for the reader with sensitivity of −80 dBm.

  14. The Camino intracranial pressure device in clinical practice. Assessment in a 1000 cases.

    Science.gov (United States)

    Gelabert-González, M; Ginesta-Galan, V; Sernamito-García, R; Allut, A G; Bandin-Diéguez, J; Rumbo, R M

    2006-04-01

    Intracranial pressure (ICP) monitoring has become standard in the management of neurocritical patients. A variety of monitoring techniques and devices are available, each offering advantages and disadvantages. Analysis of large populations has never been performed. A prospective study was designed to evaluate the Camino fiberoptic intraparenchymal cerebral pressure monitor for complications and accuracy. Between 1992-2004 one thousand consecutive patients had a fiberoptic ICP monitor placed. The most frequent indication for monitoring was severe head injury (697 cases). The average duration of ICP monitoring was 184.6 +/- 94.3 hours; the range was 16-581 hours. Zero drift (range, -17 to 21 mm Hg; mean 7.3 +/- 5.1) was recorded after the devices were removed from 624 patients. Mechanical complications such as: breakage of the optical fiber (n = 17); dislocations of the fixation screw (n = 15) or the probe (n = 13); and failure of ICP recording for unknown reasons (n = 4) were found in 49 Camino devices. The Camino ICP sensor remains one of the most popular ICP monitoring devices for use in critical neurosurgical patients. The system offers reliable ICP measurements in an acceptable percentage of device complications and the advantage of in vivo recalibration. The incidence of technical complications was low and similar to others devices.

  15. The relationship between intracranial pressure and size of cerebral ventricles assessed by computed tomography.

    Science.gov (United States)

    Eide, P K

    2003-03-01

    This study explored whether assessment of the cerebral ventricular size (or changes in size) by cranial computed tomography (CT) is a reliable way to predict the intracranial pressure (ICP). A total of 224 cranial CT scans and continuous 24 hours ICP recordings in 184 patients were examined and compared. In these cases examinations were undertaken on the basis of suspected craniosynostosis, hydrocephalus or extracranial shunt failure. Simultaneous CT scanning and ICP monitoring was performed twice in 31 cases. Various measures of cerebral ventricular size were computed on the basis of CT, including Evan's index, third ventricular index, cella media index and ventricular score. Various measures of ICP were computed by means of the software Sensometrics Pressure Analyser, including computation of mean ICP, numbers of ICP elevations (20-30 mmHg lasting either 0.5, 1, 5 or 10 minutes), and numbers of ICP depressions (-5 or -10 mmHg lasting either 0.5, 1, 5 or 10 minutes) during a standardized recording time of 10 hours. The relationships between the various measures of ventricular size and the various measures of ICP were explored. There was a weak and non-significant relationship between the various measures of ventricular size and the measures of ICP in the 184 cases. There was a weak relationship between changes in size of cerebral ventricles and changes in ICP in the 31 cases examined twice. The present results suggest that actual size or changes in size of the cerebral ventricles were no reliable predictors of ICP or changes in ICP, suggesting that great caution should be exercised when predicting ICP on the basis of the size of the cerebral ventricles on cranial CT scanning.

  16. Changes in Cerebral Partial Oxygen Pressure and Cerebrovascular Reactivity During Intracranial Pressure Plateau Waves.

    Science.gov (United States)

    Lang, Erhard W; Kasprowicz, Magdalena; Smielewski, Peter; Pickard, John; Czosnyka, Marek

    2015-08-01

    Plateau waves in intracranial pressure (ICP) are frequently recorded in neuro intensive care and are not yet fully understood. To further investigate this phenomenon, we analyzed partial pressure of cerebral oxygen (pbtO2) and a moving correlation coefficient between ICP and mean arterial blood pressure (ABP), called PRx, along with the cerebral oxygen reactivity index (ORx), which is a moving correlation coefficient between cerebral perfusion pressure (CPP) and pbtO2 in an observational study. We analyzed 55 plateau waves in 20 patients after severe traumatic brain injury. We calculated ABP, ABP pulse amplitude (ampABP), ICP, CPP, pbtO2, heart rate (HR), ICP pulse amplitude (ampICP), PRx, and ORx, before, during, and after each plateau wave. The analysis of variance with Bonferroni post hoc test was used to compare the differences in the variables before, during, and after the plateau wave. We considered all plateau waves, even in the same patient, independent because they are separated by long intervals. We found increases for ICP and ampICP according to our operational definitions for plateau waves. PRx increased significantly (p = 0.00026), CPP (p waves. ABP, ampABP, and HR remained unchanged. PRx during the plateau was higher than before the onset of wave in 40 cases (73 %) with no differences in baseline parameters for those with negative and positive ΔPRx (difference during and after). ORx showed an increase during and a decrease after the plateau waves, however, not statistically significant. PbtO2 overshoot after the wave occurred in 35 times (64 %), the mean difference was 4.9 ± 4.6 Hg (mean ± SD), and we found no difference in baseline parameters between those who overshoot and those who did not overshoot. Arterial blood pressure remains stable in ICP plateau waves, while cerebral autoregulatory indices show distinct changes, which indicate cerebrovascular reactivity impairment at the top of the wave. PbtO2 decreases during the waves and may

  17. A novel method for long-term monitoring of intracranial pressure in rats

    DEFF Research Database (Denmark)

    Uldall, Maria Schmidt; Juhler, Marianne; Skjolding, Anders Daehli;

    2014-01-01

    BACKGROUND: In preclinical neurological studies, monitoring intracranial pressure (ICP) in animal models especially in rodents is challenging. Further, the lack of methods for long-term ICP monitoring has limited the possibilities to conduct prolonged studies on ICP fluctuations in parallel...... and in the epidural space. The two pressures were recorded twice a week for 59 days and the correlation was studied. RESULTS: The two pressure recordings correlated exceptionally well and the R(2) values on each recording day ranged between 0.99 and 1.00. However, the ventricular probes caused a number...

  18. Postural influence on intracranial and cerebral perfusion pressure in ambulatory neurosurgical patients

    DEFF Research Database (Denmark)

    Petersen, Lonnie Grove; Petersen, Johan Casper Grove; Andresen, Morten;

    2016-01-01

    We evaluated postural effects on intracranial pressure (ICP) and cerebral perfusion pressure (CPP: mean arterial pressure (MAP) - ICP) in neurosurgical patients undergoing 24-hour ICP monitoring as part of their diagnostic workup. We identified 9 patients (5 women, age 44±20 yrs.; mean±SD) who were...... "as normal as possible" i.e. without indication for neurosurgical intervention (e.g. focal lesions, global edema, abnormalities in ICP-profile or cerebrospinal fluid dynamics). ICP (tip-transducer probe, Raumedic) in the brain parenchyma (N=7) or in the lateral ventricles (N=2) and cardiovascular...

  19. Raised intracranial pressure as a result of pansynostosis in a child with Albright's hereditary osteodystrophy

    DEFF Research Database (Denmark)

    Mamoei, Sepehr; Cortnum, Søren

    2017-01-01

    CASE: The authors describe the case of an 8-year-old boy with pansynostosis in the context of Albright's hereditary osteodystrophy (AHO). This condition had lead to raised intracranial pressure (ICP). The elevated ICP was a consequence of the rigid skull impeding brain growth. Therefore, a decomp......CASE: The authors describe the case of an 8-year-old boy with pansynostosis in the context of Albright's hereditary osteodystrophy (AHO). This condition had lead to raised intracranial pressure (ICP). The elevated ICP was a consequence of the rigid skull impeding brain growth. Therefore......, a decompressive cranioplasty was performed successfully, leaving further space for the growing brain. Affection of the central nervous system has been documented in AHO. However, affection of the skull bones has rarely been described in literature. CONCLUSION: We suggest that craniosynostosis may develop...

  20. Adult Neuroblastoma Complicated by Increased Intracranial Pressure: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Patrick L. Stevens

    2014-01-01

    Full Text Available Neuroblastoma is the third most commonly occurring malignancy of the pediatric population, although it is extremely rare in the adult population. In adults, neuroblastoma is often metastatic and portends an extremely poor overall survival. Our case report documents metastatic neuroblastoma occurring in a healthy 29-year-old woman whose course was complicated by an unusual presentation of elevated intracranial pressures. The patient was treated with systemic chemotherapy, I131 metaiodobenzylguanidine (MIBG radiotherapy, and autologous stem cell transplant (SCT. Unfortunately the patient’s response to therapy was limited and she subsequently died. We aim to review neuroblastoma in the context of increased intracranial pressure and the limited data of neuroblastoma occurring in the adult population, along with proposed treatment options.

  1. The effects of sevoflurane and isoflurane on intracranial pressure and cerebral perfusion pressure after diffuse brain injury in rats.

    Science.gov (United States)

    Goren, S; Kahveci, N; Alkan, T; Goren, B; Korfali, E

    2001-04-01

    Twenty-four adult male Wistar rats, weighing 220 to 290 g, were anesthetized with 30 mg/kg intraperitoneal sodium thiopental, then underwent a tracheostomy. After diffuse impact-acceleration brain injury (BI) was induced, each rat was paralyzed and mechanically ventilated with 30% O2 in nitrous oxide (N2O). The rats were assigned randomly to two groups, each of which received one of the two volatile anesthetic agents, sevoflurane or isoflurane. The anesthetics were administered at 0.5, 0.75, 1.0, and 1.25 minimal alveolar concentration (MAC) for 30 minutes each, respectively, and anesthesia was maintained at 0.75 MAC during the last hour of the study period. Intracranial pressure (ICP), mean arterial pressure (MAP), rectal and intrahemispheric temperatures, and end-tidal volatile anesthetic concentrations were monitored continuously throughout the 3 hours, with measurements recorded every 15 minutes. At baseline, there were no significant differences between the two groups regarding the monitored physiologic values. In the sevoflurane group, MAP fell significantly after 45 minutes, and a similar change was observed in the isoflurane group after 30 minutes (P pressure increased significantly at 45 minutes in the sevoflurane group (P isoflurane group, the change was not significant. Cerebral perfusion pressure (CPP) decreased in parallel with MAP, with the reduction in the sevoflurane group being more pronounced than that in the isoflurane group. The results demonstrated that, under the conditions of diffuse BI, animals that were anesthetized with sevoflurane had higher ICP and lower CPP levels than those anesthetized with isoflurane.

  2. Hypertonic/Hyperoncotic Resuscitation from Shock: Reduced Volume Requirement and Lower Intracranial Pressure

    Science.gov (United States)

    1989-10-01

    Volume 15, No. 4 ABSTRACTS OF PAPERS 433 INTRACRANIAL PRESSURE FOLLOWING RESUSCITATION FROM HEMORRHAGIC SHOCK John H. Whitley, Donald S. Prough, Michael ...SHOCK: COMPARISON OF FLUIDS John M. Whitley, PhD, Michael A. Olympio, MD, Donald S. Prough, MD Department of Anesthesia, Bowman Gray School of Medicine...fluid infused within the range of sodium and colloid concentrations examined in this study. In contrast, Gunnar et al.7’ 2 and Ducey et al.,8

  3. Research on simulation and experiment of noninvasive intracranial pressure monitoring based on acoustoelasticity effects

    OpenAIRE

    Wu J.; He W; Chen W; Zhu L

    2013-01-01

    Jun Wu1, Wei He2, Wei-min Chen1, Lian Zhu21Key Laboratory of Optoelectronic Technology and Systems, 2State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing, People’s Republic of ChinaAbstract: The real-time monitoring of intracranial pressure (ICP) is very important for craniocerebrally critically ill patients, but it is very difficult to realize long-time monitoring for the traditional invasive method, which very...

  4. Influence of an increased intracranial pressure on cerebral and systemic haemodynamics during endoscopic neurosurgery : an animal model

    NARCIS (Netherlands)

    Kalmar, A. F.; De Ley, G.; Van Den Broecke, C.; Van Aken, J.; Struys, M. M. R. F.; Praet, M. M.; Mortier, E. P.

    2009-01-01

    During endoscopic neurosurgery, direct mechanical stimulation of the brain by the endoscope and increased intracranial pressure (ICP) caused by the continuous rinsing can induce potentially lethal haemodynamic reflexes, brain ischaemia, and excessive fluid resorption. In a newly presented rat model

  5. Influence of an increased intracranial pressure on cerebral and systemic haemodynamics during endoscopic neurosurgery : an animal model

    NARCIS (Netherlands)

    Kalmar, A. F.; De Ley, G.; Van Den Broecke, C.; Van Aken, J.; Struys, M. M. R. F.; Praet, M. M.; Mortier, E. P.

    2009-01-01

    During endoscopic neurosurgery, direct mechanical stimulation of the brain by the endoscope and increased intracranial pressure (ICP) caused by the continuous rinsing can induce potentially lethal haemodynamic reflexes, brain ischaemia, and excessive fluid resorption. In a newly presented rat model

  6. The effect of increased intracranial pressure on vestibular evoked myogenic potentials in superior canal dehiscence syndrome.

    Science.gov (United States)

    Janky, Kristen L; Zuniga, M Geraldine; Schubert, Michael C; Carey, John P

    2015-04-01

    To determine if vestibular evoked myogenic potential (VEMP) responses change during inversion in patients with superior canal dehiscence syndrome (SCDS) compared to controls. Sixteen subjects with SCDS (mean: 43, range 30-57 years) and 15 age-matched, healthy subjects (mean: 41, range 22-57 years) completed cervical VEMP (cVEMP) in response to air conduction click stimuli and ocular VEMP (oVEMP) in response to air conduction 500 Hz tone burst stimuli and midline tap stimulation. All VEMP testing was completed in semi-recumbent and inverted conditions. SCDS ears demonstrated significantly larger oVEMP peak-to-peak amplitudes in comparison to normal ears in semi-recumbency. While corrected cVEMP peak-to-peak amplitudes were larger in SCDS ears; this did not reach significance in our sample. Overall, there was not a differential change in o- or cVEMP amplitude with inversion between SCDS and normal subjects. Postural-induced changes in o- and cVEMP responses were measured in the steady state regardless of whether the labyrinth was intact or dehiscent. VEMP responses are blunted during inversion. Although steady-state measurements of VEMPs during inversion do not increase diagnostic accuracy for SCDS, the findings suggest that inversion may provide more general insights into the equilibration of pressures between intracranial and intralabyrinthine fluids. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  7. Advances in Intracranial Pressure Monitoring and Its Significance in Managing Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Usmah Kawoos

    2015-12-01

    Full Text Available Intracranial pressure (ICP measurements are essential in evaluation and treatment of neurological disorders such as subarachnoid and intracerebral hemorrhage, ischemic stroke, hydrocephalus, meningitis/encephalitis, and traumatic brain injury (TBI. The techniques of ICP monitoring have evolved from invasive to non-invasive—with both limitations and advantages. Some limitations of the invasive methods include short-term monitoring, risk of infection, restricted mobility of the subject, etc. The invasiveness of a method limits the frequency of ICP evaluation in neurological conditions like hydrocephalus, thus hampering the long-term care of patients with compromised ICP. Thus, there has been substantial interest in developing noninvasive techniques for assessment of ICP. Several approaches were reported, although none seem to provide a complete solution due to inaccuracy. ICP measurements are fundamental for immediate care of TBI patients in the acute stages of severe TBI injury. In severe TBI, elevated ICP is associated with mortality or poor clinical outcome. ICP monitoring in conjunction with other neurological monitoring can aid in understanding the pathophysiology of brain damage. This review article presents: (a the significance of ICP monitoring; (b ICP monitoring methods (invasive and non-invasive; and (c the role of ICP monitoring in the management of brain damage, especially TBI.

  8. Advances in Intracranial Pressure Monitoring and Its Significance in Managing Traumatic Brain Injury.

    Science.gov (United States)

    Kawoos, Usmah; McCarron, Richard M; Auker, Charles R; Chavko, Mikulas

    2015-12-04

    Intracranial pressure (ICP) measurements are essential in evaluation and treatment of neurological disorders such as subarachnoid and intracerebral hemorrhage, ischemic stroke, hydrocephalus, meningitis/encephalitis, and traumatic brain injury (TBI). The techniques of ICP monitoring have evolved from invasive to non-invasive-with both limitations and advantages. Some limitations of the invasive methods include short-term monitoring, risk of infection, restricted mobility of the subject, etc. The invasiveness of a method limits the frequency of ICP evaluation in neurological conditions like hydrocephalus, thus hampering the long-term care of patients with compromised ICP. Thus, there has been substantial interest in developing noninvasive techniques for assessment of ICP. Several approaches were reported, although none seem to provide a complete solution due to inaccuracy. ICP measurements are fundamental for immediate care of TBI patients in the acute stages of severe TBI injury. In severe TBI, elevated ICP is associated with mortality or poor clinical outcome. ICP monitoring in conjunction with other neurological monitoring can aid in understanding the pathophysiology of brain damage. This review article presents: (a) the significance of ICP monitoring; (b) ICP monitoring methods (invasive and non-invasive); and (c) the role of ICP monitoring in the management of brain damage, especially TBI.

  9. Cerebral blood flow and intracranial pulsatility studied with MRI: measurement, physiological and pathophysiological aspects

    Energy Technology Data Exchange (ETDEWEB)

    Waahlin, Anders

    2012-07-01

    stress were assessed in healthy elderly. The biomarkers were extracted from invasive CSF pressure measurements as well as 2D PCMRI acquisitions. The volumes of temporal cortex, frontal cortex and hippocampus were negatively related to the magnitude of cardiac-related intracranial pulsatility. Finally, a potentially improved workflow to assess the volume of arterial pulsatility using time resolved, four-dimensional phase contrast MRI measurements (4D PCMRI) was evaluated. The measurements showed good agreement with 2D PCMRI acquisitions. In conclusion, this work showed that 2D PCMRI is a feasible tool to study the pulsatile waveforms of cerebral blood and CSF flow. Conventional views regarding the magnitude and distribution of craniospinal compliance was challenged, with important implications regarding the understanding of how intracranial vascular pulsatility is absorbed. A first counterpoint to previous near-uniform observations of obstructions in the internal jugular veins in multiple sclerosis was provided. It was demonstrated that large cardiac- related intracranial pulsatility were related to smaller volumes of brain regions that are important in neurodegenerative diseases among elderly. This represents a strong rationale to further investigate the role of excessive intracranial pulsatility in cognitive impairment and dementia. For that work, 4D PCMRI will facilitate an effective analysis of cerebral blood flow and pulsatility.

  10. The Visual Impairment Intracranial Pressure Syndrome in Long Duration NASA Astronauts: An Integrated Approach

    Science.gov (United States)

    Otto, C. A.; Norsk, P.; Shelhamer, M. J.; Davis, J. R.

    2015-01-01

    The Visual Impairment Intracranial Pressure (VIIP) syndrome is currently NASA's number one human space flight risk. The syndrome, which is related to microgravity exposure, manifests with changes in visual acuity (hyperopic shifts, scotomas), changes in eye structure (optic disc edema, choroidal folds, cotton wool spots, globe flattening, and distended optic nerve sheaths). In some cases, elevated cerebrospinal fluid pressure has been documented postflight reflecting increased intracranial pressure (ICP). While the eye appears to be the main affected end organ of this syndrome, the ocular affects are thought to be related to the effect of cephalad fluid shift on the vascular system and the central nervous system. The leading hypotheses for the development of VIIP involve microgravity induced head-ward fluid shifts along with a loss of gravity-assisted drainage of venous blood from the brain, both leading to cephalic congestion and increased ICP. Although not all crewmembers have manifested clinical signs or symptoms of the VIIP syndrome, it is assumed that all astronauts exposed to microgravity have some degree of ICP elevation in-flight. Prolonged elevations of ICP can cause long-term reduced visual acuity and loss of peripheral visual fields, and has been reported to cause mild cognitive impairment in the analog terrestrial population of Idiopathic Intracranial Hypertension (IIH). These potentially irreversible health consequences underscore the importance of identifying the factors that lead to this syndrome and mitigating them.

  11. [Hierarchical strategy for treating elevated intracranial pressure in severe traumatic brain injury].

    Science.gov (United States)

    Orban, J-C; Ichai, C

    2007-05-01

    The objective of the treatment of intracranial hypertension is to decrease intracranial pressure (ICP) while maintaining cerebral blood flow (CBF). Despite numerous treatments, none of them associates total efficiency and security. Systemic secondary cerebral injuries, which are responsible for cerebral ischemia, lead us to administer non specific treatments in order to optimize CBF and cerebral oxygenation. Thus, the goals are: 1) to maintain cerebral perfusion pressure> or =70 mmHg; 2) to control metabolic status by preventing hyperglycaemia, anaemia and hyperthermia; 3) to maintain normoxia and normocapnia (hypercapnia increases ICP and hypocapnia decreases CBF). Beside the neurosurgical evacuation of extra- and intraparenchymatous haematomas, osmotherapy and cerebrospinal fluid (CSF) evacuation are the two specific treatments of intracranial hypertension. Osmotherapy consists in an administration of a hypertonic solution which induces a decrease in cerebral water and finally in ICP. Mannitol (20%), which is the reference, associates osmotic and rheologic effects, and decreases CSF production too. Recent data conduct us to administer larger doses, between 0.7 and 1 g/kg in 15 minutes. Hypertonic saline solution associates osmotic effects and plasma volume loading. Thus, this solution is particularly appropriate in severe head injury with arterial hypotension. CBF evacuation decreases rapidly ICP without any major side-effect. Until now, there is no proof of a superior efficiency of a treatment for intracranial hypertension compared to another. Considering their mechanism of action, all of them are efficient but potentially dangerous too. Indeed, the choice between treatments depends on data which are issued from the multimodal monitoring. General non specific treatments are always necessary. Specific treatments are indicated if ICP is above 20-25 mmHg. Maintaining cerebral perfusion pressure represents the first therapeutic goal. If intracranial hypertension

  12. MRI evidence for preserved regulation of intracranial pressure in patients with cerebral arteriovenous malformations

    Energy Technology Data Exchange (ETDEWEB)

    Meinel, Felix G.; Fischer, Judith; Pomschar, Andreas; Wöhrle, Natalie; Koerte, Inga K.; Steffinger, Denise [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377 Munich (Germany); Laubender, Rüdiger P. [Institute of Medical Informatics, Biometry and Epidemiology, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich (Germany); Muacevic, Alexander [European Cyberknife Center Munich, 81377 Munich (Germany); Reiser, Maximilian F. [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377 Munich (Germany); Alperin, Noam [Department of Radiology, Miller School of Medicine, University of Miami, Miami, FL 33136 (United States); Ertl-Wagner, Birgit, E-mail: birgit.ertl-wagner@med.uni-muenchen.de [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital, Marchioninistr. 15, 81377 Munich (Germany)

    2014-08-15

    Purpose: The purpose of this study was to investigate intracranial pressure and associated hemo- and hydrodynamic parameters in patients with cerebral arteriovenous malformations AVMs. Methods: Thirty consecutive patients with arteriovenous malformations (median age 38.7 years, 27/30 previously treated with radiosurgery) and 30 age- and gender-matched healthy controls were investigated on a 3.0 T MR scanner. Nidus volume was quantified on dynamic MR angiography. Total arterial cerebral blood flow (tCBF), venous outflow as well as aqueductal and craniospinal stroke volumes were obtained using velocity-encoded cine-phase contrast MRI. Intracranial volume change during the cardiac cycle was calculated and intracranial pressure (ICP) was derived from systolic intracranial volume change (ICVC) and pulse pressure gradient. Results: TCBF was significantly higher in AVM patients as compared to healthy controls (median 799 vs. 692 mL/min, p = 0.007). There was a trend for venous flow to be increased in both the ipsilateral internal jugular vein (IJV, 282 vs. 225 mL/min, p = 0.16), and in the contralateral IJV (322 vs. 285 mL/min, p = 0.09), but not in secondary veins. There was no significant difference in median ICP between AVM patients and control subjects (6.9 vs. 8.6 mmHg, p = 0.30) and ICP did not correlate with nidus volume in AVM patients (ρ = −0.06, p = 0.74). There was a significant positive correlation between tCBF and craniospinal CSF stroke volume (ρ = 0.69, p = 0.02). Conclusions: The elevated cerebral blood flow in patients with AVMs is drained through an increased flow in IJVs but not secondary veins. ICP is maintained within ranges of normal and does not correlate with nidus volume.

  13. NASA's Current Evidence and Hypothesis for the Visual Impairment and Intracranial Pressure Risk

    Science.gov (United States)

    Otto, Christian A.; Norsk, Peter; Oubre, Cherie M.; Pass, Anastas F.; Tarver, William

    2012-01-01

    While 40 years of human spaceflight exploration has reported visual decrement to a certain extent in a subgroup of astronauts, recent data suggests that there is indeed a subset of crewmembers that experience refraction changes (hyperoptic shift), cotton wool spot formation, choroidal fold development, papilledema, optic nerve sheath distention and/or posterior globe flattening with varying degrees of severity and permanence. Pre and postflight ocular measures have identified a potential risk of permanent visual changes as a result of microgravity exposure, which has been defined as the Visual Impairment and Intracranial Pressure risk (VIIP). The combination of symptoms are referred to as the VIIP syndrome. It is thought that the ocular structural and optic nerve changes are caused by events precipitated by the cephalad fluid shift crewmembers experience during long-duration spaceflight. Three important systems, ocular, cardiovascular, and central nervous, seem to be involved in the development of symptoms, but the etiology is still under speculation. It is believed that some crewmembers are more susceptible to these changes due to genetic/anatomical predisposition or lifestyle (fitness) related factors. Future research will focus on determining the etiology of the VIIP syndrome and development of mechanisms to mitigate the spaceflight risk.

  14. Correlation of cell apoptosis with brain edema and elevated intracranial pressure in traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-feng; LIU Wei-guo; SHEN Hong; GONG Jiang-biao; YU Jun; HU Wei-wei; L(U) Shi-ting; ZHENG Xiu-jue; FU Wei-ming

    2005-01-01

    Objective: To study the correlation between brain edema, elevated intracranial pressure (ICP) and cell apoptosis in traumatic brain injury (TBI). Methods: In this study, totally 42 rabbits in 7 groups were studied. Six of the animals were identified as a control group, and the remaining 36 animals were equally divided into 6 TBI groups. TBI models were produced by the modified method of Feeney. After the impact, ICP of each subject was recorded continuously by an ICP monitor until the animal was sacrificed at scheduled time. The apoptotic brain cells were detected by an terminal deoxynucleotide-transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay. Cerebral water content (CWC) was measured with a drying method and calculated according to the Elliott formula. Then, an analysis was conducted to determine the correlation between the count of apoptotic cells and the clinical pathological changes of the brain. Results: Apoptotic cell count began to increase 2 h after the impact, and reached its maximum about 3 days after the impact. The peak value of CWC and ICP appeared 1 day and 3 days after the impact, respectively. Apoptotic cell count had a positive correlation with CWC and ICP. Conclusions: In TBI, occurrence of brain edema and ICP increase might lead to apoptosis of brain cells. Any therapy which can relieve brain edema and/or decrease ICP would be able to reduce neuron apoptosis, thereby to attenuate the secondary brain damage.

  15. The effect of head-down tilt and water immersion on intracranial pressure in nonhuman primates

    Science.gov (United States)

    Keil, Lanny C.; Mckeever, Kenneth H.; Skidmore, Michael G.; Hines, John; Severs, Walter B.

    1992-01-01

    Intracranial pressure (ICP) is investigated in primates during and after -6-deg head-down tilt (HDT) and immersion in water to examine the effects of the headward fluid shift related to spaceflight. Following the HDT the primates are subjected to head-out thermoneutral water immersion, and the ICP is subsequently measured. ICP is found to increase from 3.8 +/- 1.1 to 5.3 +/- 1.3 mm Hg during the horizontal control period. ICP stabilizes at -6.3 +/- 1.3 mm Hg and then increases to -2.2 +/- 1.9 mm Hg during partial immersion, and ICP subsequently returns to preimmersion levels after immersion. These data indicate that exposure to HDT or water immersion lead to an early sharp increase in ICP, and water immersion alone leads to higher ICP levels. A significant conclusion of the work is that the ICP did not approach pathological levels, and this finding is relevant to human spaceflight research.

  16. Automated midline shift and intracranial pressure estimation based on brain CT images.

    Science.gov (United States)

    Chen, Wenan; Belle, Ashwin; Cockrell, Charles; Ward, Kevin R; Najarian, Kayvan

    2013-04-13

    In this paper we present an automated system based mainly on the computed tomography (CT) images consisting of two main components: the midline shift estimation and intracranial pressure (ICP) pre-screening system. To estimate the midline shift, first an estimation of the ideal midline is performed based on the symmetry of the skull and anatomical features in the brain CT scan. Then, segmentation of the ventricles from the CT scan is performed and used as a guide for the identification of the actual midline through shape matching. These processes mimic the measuring process by physicians and have shown promising results in the evaluation. In the second component, more features are extracted related to ICP, such as the texture information, blood amount from CT scans and other recorded features, such as age, injury severity score to estimate the ICP are also incorporated. Machine learning techniques including feature selection and classification, such as Support Vector Machines (SVMs), are employed to build the prediction model using RapidMiner. The evaluation of the prediction shows potential usefulness of the model. The estimated ideal midline shift and predicted ICP levels may be used as a fast pre-screening step for physicians to make decisions, so as to recommend for or against invasive ICP monitoring.

  17. Elevated intracranial pressure and reversible eye-tracking changes detected while viewing a film clip.

    Science.gov (United States)

    Kolecki, Radek; Dammavalam, Vikalpa; Bin Zahid, Abdullah; Hubbard, Molly; Choudhry, Osamah; Reyes, Marleen; Han, ByoungJun; Wang, Tom; Papas, Paraskevi Vivian; Adem, Aylin; North, Emily; Gilbertson, David T; Kondziolka, Douglas; Huang, Jason H; Huang, Paul P; Samadani, Uzma

    2017-06-02

    OBJECTIVE The precise threshold differentiating normal and elevated intracranial pressure (ICP) is variable among individuals. In the context of several pathophysiological conditions, elevated ICP leads to abnormalities in global cerebral functioning and impacts the function of cranial nerves (CNs), either or both of which may contribute to ocular dysmotility. The purpose of this study was to assess the impact of elevated ICP on eye-tracking performed while patients were watching a short film clip. METHODS Awake patients requiring placement of an ICP monitor for clinical purposes underwent eye tracking while watching a 220-second continuously playing video moving around the perimeter of a viewing monitor. Pupil position was recorded at 500 Hz and metrics associated with each eye individually and both eyes together were calculated. Linear regression with generalized estimating equations was performed to test the association of eye-tracking metrics with changes in ICP. RESULTS Eye tracking was performed at ICP levels ranging from -3 to 30 mm Hg in 23 patients (12 women, 11 men, mean age 46.8 years) on 55 separate occasions. Eye-tracking measures correlating with CN function linearly decreased with increasing ICP (p eye-tracking metrics to discriminate between ICP eye tracking detected while patients were watching a short film clip. These results suggest that eye tracking may be used as a noninvasive, automatable means to quantitate the physiological impact of elevated ICP, which has clinical application for assessment of shunt malfunction, pseudotumor cerebri, concussion, and prevention of second-impact syndrome.

  18. Noninvasive Intracranial Pressure Monitoring Using Advanced Machine Learning Techniques

    Science.gov (United States)

    2013-11-01

    the intermittent nature of IVC ICP measurement, as well as our requirement for continuously measured ICP, we removed IVC ICP segments by reviewing all...Res 2010; 164(2):286-93. 5. Goodman MD, Makley AT, Huber NL, et al. Hypobaric hypoxia exacerbates the neuroinflammatory response to traumatic brain

  19. Third ventriculostomy through the lamina terminalis for intracranial pressure monitoring after aneurysm surgery: technical note

    Directory of Open Access Journals (Sweden)

    Kraemer Jorge L.

    2002-01-01

    Full Text Available OBJECTIVE: A new ventriculostomy technique through the lamina terminalis is described. This technique is applied mainly during aneurysm surgery at the acute stage. METHOD: Thirteen patients were operated on intracranial aneurysms and, during the procedure, had the lamina terminalis fenestrated. A ventricular catheter was inserted into the third ventricule, left in place and connected to an external drainage system for further intracranial pressure (ICP monitoring and/or cerebrospinal fluid (CSF drainage. RESULTS: ICP readings and CSF drainage were obtained in all cases. No complication was recorded. CONCLUSION: Third ventriculostomy through the lamina terminalis is a simple and easy technique that can be used as an alternative to conventional ventriculostomy. This procedure can be indicated in cases where the ventricule is not reached by means of another technique, and when the decision to perform ventriculostomy is made at the end of aneurysm surgery.

  20. Neurovascular compression and decompression of the intracranial vagus for blood pressure

    Institute of Scientific and Technical Information of China (English)

    Kehua Sun; Yicheng Lu; Qifu Tan; Hua Fu; Lijun Hou

    2007-01-01

    BACKGROUND: Previous researches demonstrated that neurovascular decompression could cure hypertension; however, whether it could effectively control refractory hypertension after hypertensive cerebral hemorrhage should be further studied.OBJECTIVE: To observe the effect of neruovascular compression on intracranial vagus for blood pressure of dogs and investigate the effect of neurovascular decompression on blood pressure of patients with hypertensive cerebral hemorrhage.DESIGN: Randomized controlled animal study, clinical effects and retrospective analysis.SETTING: Department of Neurosurgery, Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA.MATERIALS: The experiment was carried out in the Department of Neurosurgery, Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA from May to October 2006. A total of 15 healthy adult dogs of both genders were randomly divided into experimental group (n =10) and control group (n =5). Clinical observation: A total of 41 patients with hypertensive cerebral hemorrhage were selected from the Department of Neurosurgery, General Hospital of Nanjing Military Area Command of Chinese PLA and the Department of Neurosurgery, Changzheng Hospital Affiliated to the Second Military Medical University of Chinese PLA from October 1999 to October 2006. Among them, one patient had brain stem hemorrhage. There were 27 males and 14 females aged from 41 to 66 years. Inclusion criteria: All patients were diagnosed with CT examination once or several times. Volume of hematoma ranged from 50 to 120 mL and had obviously operative indication. All patients provided consents. In addition, another 281patients with hypertensive cerebral hemorrhage who received traditionally intemal and surgical therapies in our departments of neurosurgery, neurology and emergency room were selected in the control group.METHODS: ① Animal experiments: 20 cm autochthonous great saphenous vein was taken

  1. Noninvasive intracranial pressure monitoring via optic nerve sheath diameter for robotic surgery in steep Trendelenburg position

    Directory of Open Access Journals (Sweden)

    Shagun Bhatia Shah

    2015-01-01

    Full Text Available Background: Recent reports of increased intracranial pressure (ICP due to steep Trendelenburg (ST position causing neurological deterioration, decreased regional cerebral oxygen saturation and postoperative visual loss after robotic urological and gynecological surgeries led us to consider a simple technique of ICP monitoring. Ours is one of the first instances reported of quantitative noninvasive measurement of increase in ICP with ST position by serial measurement of binocular optic nerve sheath diameter (ONSD in patients undergoing robot assisted urological and gynecological oncosurgery. We tested whether ONSD values rose to above the upper limits of normal and for what length of time they remained elevated. Materials and Methods: Prospective, randomized, interventional, parallel group, active control study conducted on 252 American Society of Anesthesiologists I and II patients. ONSD was measured using 7.5 MHz linear ultrasound probe in supine and Trendelenburg positions. Statistics: Student′s t-test to compare the inter-group mean ONSD and the repetitive t-test for intra-group analysis. Result: Comparison of the mean ONSD values of both groups yielded a 2-tailed significance P <0.01 at all compared time points intra- and post-operatively. In Group-O (open surgery; supine position, the baseline mean bilateral ONSD was 4.36 mm, which did not show any statistically significant change throughout open surgery and postoperative period. On de-docking the robot, 6.2 mm was the mean ONSD value in Group-R (robotic group while 4.3 mm was the corresponding value in control Group-O. Conclusion: ONSD evaluation is a simple, quick, safe, readily available, reliable, cost effective, noninvasive, potential standard of care for screening and monitoring of patients undergoing robotic surgery in ST position.

  2. Increased Intracranial Pressure during Hemodialysis in a Patient with Anoxic Brain Injury

    Directory of Open Access Journals (Sweden)

    Anton Lund

    2017-01-01

    Full Text Available Dialysis disequilibrium syndrome (DDS is a serious neurological complication of hemodialysis, and patients with acute brain injury are at increased risk. We report a case of DDS leading to intracranial hypertension in a patient with anoxic brain injury and discuss the subsequent dialysis strategy. A 13-year-old girl was admitted after prolonged resuscitation from cardiac arrest. Computed tomography (CT revealed an inferior vena cava aneurysm and multiple pulmonary emboli as the likely cause. An intracranial pressure (ICP monitor was inserted, and, on day 3, continuous renal replacement therapy (CRRT was initiated due to acute kidney injury, during which the patient developed severe intracranial hypertension. CT of the brain showed diffuse cerebral edema. CRRT was discontinued, sedation was increased, and hypertonic saline was administered, upon which ICP normalized. Due to persistent hyperkalemia and overhydration, ultrafiltration and intermittent hemodialysis were performed separately on day 4 with a small dialyzer, low blood and dialysate flow, and high dialysate sodium content. During subsequent treatments, isolated ultrafiltration was well tolerated, whereas hemodialysis was associated with increased ICP necessitating frequent pauses or early cessation of dialysis. In patients at risk of DDS, hemodialysis should be performed with utmost care and continuous monitoring of ICP should be considered.

  3. Subdural intracranial pressure, cerebral perfusion pressure, and degree of cerebral swelling in supra- and infratentorial space-occupying lesions in children

    DEFF Research Database (Denmark)

    Stilling, M; Karatasi, E; Rasmussen, Mads

    2005-01-01

    UNLABELLED: To our knowledge comparative studies of intracranial pressure (ICP) and degree of cerebral swelling during craniotomy for supratentorial or infratentorial space occupying lesion in children are not available. In this prospective study subdural ICP, cerebral perfusion pressure (CPP......), dural tension, and the degree of cerebral swelling were analysed in supine and prone positioned children subjected to craniotomy for space occupying lesions. MATERIAL AND METHOD: 48 children with space occupying tumours were subjected to either isoflurane/nitrous oxide 50%/fentanyl (n = 22) or propofol....../fentanyl/air/oxygen (n = 26). 25 children were operated supratentorially in supine position, while 23 patients were operated infratentorially in the prone position. Subdural ICP, mean arterial blood pressure (MABP), and CPP were measured just before opening of the dura. Dural tension was estimated before opening of dura...

  4. Intracranial pressure and conductance to outflow of cerebrospinal fluid in normal-pressure hydrocephalus.

    Science.gov (United States)

    Børgesen, S E; Gjerris, F; Sørensen, S C

    1979-04-01

    Forty patients with clinical evidence of normal-pressure hydrocephalus were studied by monitoring intraventricular pressure during a 24-hour period, and by a lumboventricular perfusion test for measurement of the conductance to outflow of cerebrospinal fluid (CSF). The purpose of the study was to investigate whether there is a relationship between intraventricular pressure and conductance to outflow of CSF, and whether it is possible to use the results from pressure monitoring in the selection of patients who may be expected to benefit from shunting therapy. The conductance to outflow was used as an evaluation factor in the selection of patients to be treated by a shunt. The conductance to CSF outflow differed by twelvefold between the lowest and highest values. The level of resting intraventricular pressure was within normal limits in all patients. Accordingly, there was no evidence of a relationship between conductance to outflow and intraventricular pressure. So-called B-waves were seen more frequently in patients with decreased conductance to outflow, but were also present in patients with high conductance to outflow. Therefore, the presence of B-waves does not imply a low conductance to outflow of CSF.

  5. Noninvasive Techniques for Intracranial Pressure Assessment: A Review from Aerospace Medicine Perspective

    Science.gov (United States)

    Hamilton, Douglas R.; Sargsyan, Ashot E.; Fogarty, Jennifer; Ebert, Douglas J. W.; Polk, J. D.

    2010-01-01

    Microgravity-induced changes in fluid distribution and other physiological factors due to space flight have been implicated as the cause of increased intracranial pressure (ICP) in a number of space crewmembers. The modest levels of ICP elevation and absence of severe symptoms in this group do not warrant invasive diagnostic interventions. However, the long-term trends and residual or consequential changes secondary to the observed ICP elevation in this group are not yet known. Therefore, close attention is needed to evaluate the potential techniques of noninvasively assessing ICP, including those feasible for in-flight use. Of particular interest is continuity between ground and in-flight testing, whereby data from the same or different techniques allow reasonably dependable estimation of ICP trends and responses. Methods: A thorough review of current literature, analysis of NASA data, and interviews with subject matter experts were conducted to construct a presentation that reflects the state of the art for noninvasive ICP measurement and monitoring. Results: Multiple imaging and non-imaging modalities are available to assess ICP in terrestrial clinical and experimental environments. Imaging alternatives include magnetic resonance imaging (MRI) and high-resolution sonography. Non-imaging techniques include transcranial Doppler, certain audiological methods, and venous ophthalmodynamometry, among others. Special functional techniques have been proposed recently that allow the use of advanced MRI methods to calculate ICP in addition to the acquisition of high-resolution images. Our data include many of these applications, with several cases of correlation with lumbar puncture, the invasive "gold standard" measurement of ICP.

  6. Optic Nerve Sheath Diameter Ultrasound and the Diagnosis of Increased Intracranial Pressure.

    Science.gov (United States)

    Hylkema, Christopher

    2016-03-01

    Ultrasound has been used for almost 30 years in a wide variety of clinical applications and environments. From the austerity of battlefields to the labor and delivery ward, ultrasound has the ability to give clinicians real-time, noninvasive diagnostic imaging. Ultrasound by emergency physicians (and all nonradiologists) has become more prevalent and has been used for examinations such as the transcranial Doppler to evaluate for stroke, cardiac function, FAST and EFAST examinations for trauma, and now increased intracranial pressure (ICP) via Optic Nerve Sheath Diameter Ultrasound (ONSD). The ONSD is a valid and reliable indicator of ICP.

  7. Assessment of the usability of a digital learning technology prototype for monitoring intracranial pressure

    Directory of Open Access Journals (Sweden)

    Lilian Regina de Carvalho

    Full Text Available ABSTRACT Objective: to assess the usability of a digital learning technology prototype as a new method for minimally invasive monitoring of intracranial pressure. Method: descriptive study using a quantitative approach on assessing the usability of a prototype based on Nielsen's ten heuristics. Four experts in the area of Human-Computer interaction participated in the study. Results: the evaluation delivered eight violated heuristics and 31 usability problems in the 32 screens of the prototype. Conclusion: the suggestions of the evaluators were critical for developing an intuitive, user-friendly interface and will be included in the final version of the digital learning technology.

  8. Clinical experience with telemetric intracranial pressure monitoring in a Danish neurosurgical center

    DEFF Research Database (Denmark)

    Lilja, Alexander; Andresen, Morten; Hadi, Amer

    2014-01-01

    reading, number of ICP recording sessions (in relation to symptoms of increased ICP) and their clinical consequence. RESULTS: We included 21 patients in the evaluation (11 female and 10 male). Median age was 28 (2-83) years and median duration of disease was 11 (0-30) years. Eleven patients had various...... kinds of hydrocephalus, seven patients had idiopathic intracranial hypertension (IIH) and three patients had normal pressure hydrocephalus (NPH). Fifteen patients had a shunt prior to implantation. Median duration of implantation was 248 (49-666) days and median duration from implantation to last...

  9. Hypothermic total body washout and intracranial pressure monitoring in Stage IV Reye syndrome.

    Science.gov (United States)

    Lansky, L L; Kalavsky, S M; Brackett, C E; Wallas, C H; Reis, R L

    1977-04-01

    The number of children in this report treated with either TBW or exchange transfusions is small. Case mortality rates among children with Reye syndrome in Stage IV coma tends to be exceedingly high, varying from 50 to 100%. Intracranial pressure monitoring with the subarachnoid screw may have been an additional factor in increasing our survival data in three patients in the TBW group, since it provided continuous monitoring of ICP and allowed judicious administration of mannitol intravenously. Survival of five of six patients without neurologic sequelae in the present series has encouraged us to coninue utilization of TBW in children with Stage IV Reye syndrome.

  10. Electrostatic discharges and their effect on the validity of registered values in intracranial pressure monitors

    DEFF Research Database (Denmark)

    Andresen, Morten; Thomsen, Ole Cornelius; Juhler, Marianne

    2013-01-01

    , the authors have tried to determine if the ICP monitors from major manufacturers were affected by electrostatic discharges (ESDs), if the changes were permanent or transient in nature, and if the changes were modified by the addition of different electrical appliances normally used in the neurointensive care...... unit environment. Methods The authors established a test setup in the neurointensive care unit using a large container filled with isotonic saline, creating a phantom patient. Intracranial pressure monitors were sequentially lowered into the container and subjected to a predefined test battery of ESDs....... Results Five pressure monitors from 4 manufacturers were evaluated. Three monitors containing electrical circuitry at the tip of the transducer were all affected by ESDs. Clinically significant permanent changes in the reported ICP values for 1 pressure monitor were observed, as well as temporary...

  11. Astronaut Preflight Cardiovascular Variables Associated with Vascular Compliance are Highly Correlated with Post-Flight Eye Outcome Measures in the Visual Impairment Intracranial Pressure (VIIP) Syndrome Following Long Duration Spaceflight

    Science.gov (United States)

    Otto, Christian; Ploutz-Snyder, R.

    2015-01-01

    The detection of the first VIIP case occurred in 2005, and adequate eye outcome measures were available for 31 (67.4%) of the 46 long duration US crewmembers who had flown on the ISS since its first crewed mission in 2000. Therefore, this analysis is limited to a subgroup (22 males and 9 females). A "cardiovascular profile" for each astronaut was compiled by examining twelve individual parameters; eleven of these were preflight variables: systolic blood pressure, pulse pressure, body mass index, percentage body fat, LDL, HDL, triglycerides, use of anti-lipid medication, fasting serum glucose, and maximal oxygen uptake in ml/kg. Each of these variables was averaged across three preflight annual physical exams. Astronaut age prior to the long duration mission, and inflight salt intake was also included in the analysis. The group of cardiovascular variables for each crew member was compared with seven VIIP eye outcome variables collected during the immediate post-flight period: anterior-posterior axial length of the globe measured by ultrasound and optical biometry; optic nerve sheath diameter, optic nerve diameter, and optic nerve to sheath ratio- each measured by ultrasound and magnetic resonance imaging (MRI), intraocular pressure (IOP), change in manifest refraction, mean retinal nerve fiber layer (RNFL) on optical coherence tomography (OCT), and RNFL of the inferior and superior retinal quadrants. Since most of the VIIP eye outcome measures were added sequentially beginning in 2005, as knowledge of the syndrome improved, data were unavailable for 22.0% of the outcome measurements. To address the missing data, we employed multivariate multiple imputation techniques with predictive mean matching methods to accumulate 200 separate imputed datasets for analysis. We were able to impute data for the 22.0% of missing VIIP eye outcomes. We then applied Rubin's rules for collapsing the statistical results across our 200 multiply imputed data sets to assess the canonical

  12. Monro-Kellie 2.0: The dynamic vascular and venous pathophysiological components of intracranial pressure

    Science.gov (United States)

    2016-01-01

    For 200 years, the ‘closed box’ analogy of intracranial pressure (ICP) has underpinned neurosurgery and neuro-critical care. Cushing conceptualised the Monro-Kellie doctrine stating that a change in blood, brain or CSF volume resulted in reciprocal changes in one or both of the other two. When not possible, attempts to increase a volume further increase ICP. On this doctrine’s “truth or relative untruth” depends many of the critical procedures in the surgery of the central nervous system. However, each volume component may not deserve the equal weighting this static concept implies. The slow production of CSF (0.35 ml/min) is dwarfed by the dynamic blood in and outflow (∼700 ml/min). Neuro-critical care practice focusing on arterial and ICP regulation has been questioned. Failure of venous efferent flow to precisely match arterial afferent flow will yield immediate and dramatic changes in intracranial blood volume and pressure. Interpreting ICP without interrogating its core drivers may be misleading. Multiple clinical conditions and the cerebral effects of altitude and microgravity relate to imbalances in this dynamic rather than ICP per se. This article reviews the Monro-Kellie doctrine, categorises venous outflow limitation conditions, relates physiological mechanisms to clinical conditions and suggests specific management options. PMID:27174995

  13. A unique pattern of intracranial pressure in a patient with traumatic paroxysmal sympathetic storm.

    Science.gov (United States)

    Woo, Hyun Jin; Park, Seong Hyun; Hwang, Sung Kyoo

    2010-01-01

    Paroxysmal sympathetic storm (PSS), or diencephalic seizure, usually appears in patients with severe traumatic brain injury and is characterized by various sympathetic symptoms. The physiological effects of this syndrome are not well studied. The authors monitored intracranial pressure (ICP) in a patient with PSS and reviewed its impact on the physiology and management of the syndrome. A 12-year-old male patient was involved in a traffic accident. Upon arrival at the emergency room, his Glasgow Coma Scale score was 5 and he showed decerebration. A brain CT showed an intracerebral hematoma in the right basal ganglia, at which point craniotomy and removal of the hematoma were performed. Continuous intracranial monitoring was performed using the fiber-optic intraparenchymal method. Beginning the day after the trauma, the patient began exhibiting sympathetic symptoms including intermittent episodes of fever, tachycardia, increased blood pressure, tachypnea, diaphoresis and decerebrate rigidity. These episodes were accompanied by ICP elevation of greater than 20 mm Hg. ICP was decreased during hyperventilation, and the episodic symptoms subsided as ICP normalized. PaCO(2) was periodically altered in association with hyperventilation. Electroencephalogram did not show epileptiform discharges, and the sympathetic spells were aborted by continuous intravenous midazolam infusion. The authors report on a pattern of ICP monitoring in association with PSS. Traumatic PSS should be recognized in the appropriate setting to prevent secondary brain damage.

  14. Frank-ter Haar syndrome associated with sagittal craniosynostosis and raised intracranial pressure

    Directory of Open Access Journals (Sweden)

    Bendon Charlotte L

    2012-11-01

    Full Text Available Abstract Background Frank-ter Haar syndrome is a rare disorder associated with skeletal, cardiac, ocular and craniofacial features including hypertelorism and brachycephaly. The most common underlying genetic defect in Frank-ter Haar syndrome appears to be a mutation in the SH3PXD2B gene on chromosome 5q35.1. Craniosynostosis, or premature fusion of the calvarial sutures, has not previously been described in Frank-ter Haar syndrome. Case presentation We present a family of three affected siblings born to consanguineous parents with clinical features in keeping with a diagnosis of Frank-ter Haar syndrome. All three siblings have a novel mutation caused by the deletion of exon 13 of the SH3PXD2B gene. Two of the three siblings also have non-scaphocephalic sagittal synostosis associated with raised intracranial pressure. Conclusion The clinical features of craniosynostosis and raised intracranial pressure in this family with a confirmed diagnosis of Frank-ter Haar syndrome expand the clinical spectrum of the disease. The abnormal cranial proportions in a mouse model of the disease suggests that the association is not coincidental. The possibility of craniosynostosis should be considered in individuals with a suspected diagnosis of Frank-ter Haar syndrome.

  15. Frank-ter Haar syndrome associated with sagittal craniosynostosis and raised intracranial pressure.

    Science.gov (United States)

    Bendon, Charlotte L; Fenwick, Aimée L; Hurst, Jane A; Nürnberg, Gudrun; Nürnberg, Peter; Wall, Steven A; Wilkie, Andrew O M; Johnson, David

    2012-11-09

    Frank-ter Haar syndrome is a rare disorder associated with skeletal, cardiac, ocular and craniofacial features including hypertelorism and brachycephaly. The most common underlying genetic defect in Frank-ter Haar syndrome appears to be a mutation in the SH3PXD2B gene on chromosome 5q35.1. Craniosynostosis, or premature fusion of the calvarial sutures, has not previously been described in Frank-ter Haar syndrome. We present a family of three affected siblings born to consanguineous parents with clinical features in keeping with a diagnosis of Frank-ter Haar syndrome. All three siblings have a novel mutation caused by the deletion of exon 13 of the SH3PXD2B gene. Two of the three siblings also have non-scaphocephalic sagittal synostosis associated with raised intracranial pressure. The clinical features of craniosynostosis and raised intracranial pressure in this family with a confirmed diagnosis of Frank-ter Haar syndrome expand the clinical spectrum of the disease. The abnormal cranial proportions in a mouse model of the disease suggests that the association is not coincidental. The possibility of craniosynostosis should be considered in individuals with a suspected diagnosis of Frank-ter Haar syndrome.

  16. Chest physiotherapy on intracranial pressure of critically ill patients admitted to the intensive care unit: a systematic review.

    Science.gov (United States)

    Ferreira, Lucas Lima; Valenti, Vitor Engrácia; Vanderlei, Luiz Carlos Marques

    2013-01-01

    To analyze the outcomes of increased or decreased intracranial pressure and/or the decrease in cerebral perfusion pressure resulting from respiratory physiotherapy on critically ill patients admitted to the intensive care unit. Through a systematic review of the literature, clinical trials published between 2002 and 2012 were selected. The search involved the LILACS, SciELO, MedLine and PEDro databases using the keywords "physical therapy", "physiotherapy", "respiratory therapy" and "randomized controlled trials" combined with the keyword "intracranial pressure". In total, five studies, including a total of 164 patients between 25 and 65 years of age, reporting that respiratory physiotherapy maneuvers significantly increased intracranial pressure without changing the cerebral perfusion pressure were included. The articles addressed several techniques including vibration, vibrocompression, tapping, postural drainage, and the endotracheal aspiration maneuver. All patients required invasive mechanical ventilation. Respiratory physiotherapy leads to increased intracranial pressure. Studies suggest that there are no short-term hemodynamic or respiratory repercussions or changes in the cerebral perfusion pressure. However, none of the studies evaluated the clinical outcomes or ensured the safety of the maneuvers.

  17. 颅内压监测的临床应用:争议与前景%Clinical application of intracranial pressure monitoring:controversies and prospects

    Institute of Scientific and Technical Information of China (English)

    张锋; 刘波; 周庆九

    2014-01-01

    , future trends and clinical application of intracranial pressure monitoring technology. METHODS:First author retrieved related articles published between January 1960 and October 2013 in the databases of PubMed, Medalink, Wanfang through computers. The key words were“intracranial pressure monitoring,increased intracranial pressure, brain injury, intracranial tumors, cerebral hemorrhage, cerebrovascular disease”in English and Chinese, respectively. The total number of the retrieved articles was 160, and 69 articles up to standard were included. RESULTS AND CONCLUSION:Intracranial pressure monitoring technology is divided into invasive and noninvasive monitoring. The former is in clinical application for decades and has provided a lot of practice experience and data which makes it be increasingly mature. The latter is not widely used in clinic because of different levels of poor measurement accuracy, usage limitation, tedious methods, many influencing factors and so on. Now, there is not a monitoring method that can be used for clinical purposes with high accuracy, noninvasion, convenience and continuity. But, noninvasive multimodal monitoring is stil the trend in the development of intracranial pressure monitoring technology. Clinical y, intracranial pressure monitoring technique has been applied in the treatment of craniocerebral trauma, hypertension cerebral hemorrhage, intracranial tumor, cerebrovascular diseases, especial y in patients with craniocerebral trauma, which has accumulated plenty of clinical data. But in the majority with retrospective study, there is a lack of prospective, randomized control ed trial studies. Most studies have shown that intracranial pressure monitoring can analyze intracranial pressure changes in a timely manner, and give important reference value in judging intracranial injury and cerebral edema, guiding treatment, and estimating prognosis.

  18. Comparison of simultaneous continuous intracranial pressure (ICP) signals from a Codman and a Camino ICP sensor.

    Science.gov (United States)

    Eide, Per Kristian

    2006-07-01

    Simultaneous continuous intracranial pressure (ICP) signals from two different sensors were compared. Continuous ICP monitoring from two ICP sensors (i.e. Codman ICP MicroSensor; Johnson & Johnson, Raynham, MA and Camino OLM ICP; Camino Laboratories, San Diego, CA) placed within the brain parenchyma was performed in three patients within the intensive care unit (ICU) as part of routine management of severe subarachnoid hemorrhage. For each 6s time window mean ICP was computed, showing large differences in mean ICP values between the signals. Differences above 5 mmHg were observed in 13% of the 128,425 time windows derived from 214 h ICP recordings in these three patients. In one patient, mean ICP differed more than 10 mmHg in 23% of the time windows. Comparisons of 675,503 individual single pressure wave pairs of these 128,425 time windows revealed marginal differences in single wave amplitude (dP, i.e. pulse pressure) and latency (dT, i.e. rise time) values, suggesting that differences in mean ICP were caused by differences in baseline pressure. For the individual time windows were computed the mean wave amplitude and mean wave latency values according to a new algorithm. There were as well marginal differences between signals of mean wave amplitude and latency values. Thus, changes in baseline pressure affect mean ICP but not single pressure wave characteristics such as amplitude (dP) and (dT) latency values.

  19. In-house development of a dedicated data acquisition and monitoring system for intracranial pressure, patient posture and patient symptoms in a regional neurosciences centre.

    Science.gov (United States)

    Marsden, S P; Boddy, I J S; Strachan, R D; Chambers, I R

    2016-02-01

    Management of traumatic brain injury and cerebrospinal fluid (CSF) flow disorders can be aided by measurement and monitoring of intracranial pressure (ICP). In addition to pressure measurement, knowledge of patient symptoms and posture during monitoring are also valuable, particularly in the management of CSF flow disorders. ICP monitoring systems have been developed in this centre to meet clinical needs in the absence of commercially available solutions. An early system (mark I) was developed and the technical challenges in its design are described, along with limitations to this system that motivated the development of a new mark II system. The mark II system is then described.

  20. Intracranial Pressure Monitoring as a Part of Multimodal Monitoring Management of Patients with Critical Polytrauma: Correlation between Optimised Intensive Therapy According to Intracranial Pressure Parameters and Clinical Picture

    Science.gov (United States)

    Luca, Loredana; Rogobete, Alexandru Florin; Bedreag, Ovidiu Horea; Sarandan, Mirela; Cradigati, Carmen Alina; Papurica, Marius; Gruneantu, Anelore; Patrut, Raluca; Vernic, Corina; Dumbuleu, Corina Maria; Sandesc, Dorel

    2015-01-01

    Objective Trauma patient requires a complex therapeutic management because of multiple severe injuries or secondary complications. The most significant injury found in patients with trauma is head injury, which has the greatest impact on mortality. Intracranial pressure (ICP) monitoring is required in severe traumatic head injury because it optimises treatment based on ICP values and cerebral perfusion pressure (CPP). Methods From a total of 64 patients admitted in the intensive care unit (ICU) ‘Casa Austria’, from the Polytraumatology Clinic of the Emergency County Hospital “Pius Brinzeu” Timisoara, Romania, between January 2014 and December 2014; only patients who underwent ICP monitoring (n=10) were analysed. The study population was divided into several categories depending on the time passed since trauma to the time of installation of ICP monitoring (24 h). Comparisons were made in terms of the number of days admitted in the ICU and mortality between patients with head injury who benefited and those who did not benefit from ICP monitoring. Results The results show the positive influence of ICP monitoring on the number of admission days in ICU because of the possibility that the number of admission days to augment therapeutic effects in patients who benefited from ICP monitoring reduces by 1.93 days compared with those who did not undergo ICP monitoring. Conclusion ICP monitoring and optimizing therapy according to the ICP and CPP has significant influence on the rate of survival. ICP monitoring is necessary in all patients with head trauma injury according to recent guidelines. The main therapeutic goal in the management of the trauma patient with head injury is to minimize the destructive effects of the associated side effects. PMID:27366538

  1. Brain energy metabolism and intracranial pressure in idiopathic adult hydrocephalus syndrome

    Science.gov (United States)

    Agren-Wilsson, A; Eklund, A; Koskinen, L; Bergenheim, A; Malm, J

    2005-01-01

    Background: The symptoms in idiopathic adult hydrocephalus syndrome (IAHS) are consistent with pathology involving the periventricular white matter, presumably reflecting ischaemia and CSF hydrodynamic disturbance. Objective: To investigate whether a change in intracranial pressure (ICP) can affect energy metabolism in deep white matter. Methods: A microdialysis catheter, a brain tissue oxygen tension probe, and an ICP transducer were inserted into the periventricular white matter 0–7 mm from the right frontal horn in 10 patients with IAHS. ICP and intracerebral PtiO2 were recorded continuously during lumbar CSF constant pressure infusion test. ICP was raised to pressure levels of 35 and 45 mm Hg for 10 minutes each, after which CSF drainage was undertaken. Microdialysis samples were collected every three minutes and analysed for glucose, lactate, pyruvate, and glutamate. Results: When raising the ICP, a reversible drop in the extracellular concentrations of glucose, lactate, and pyruvate was found. Comparing the values during baseline to values at the highest pressure level, the fall in glucose, lactate, and pyruvate was significant (pintracranial pressure induces an immediate and reversible change in energy metabolism in periventricular white matter, without any sign of ischaemia. Theoretically, frequent ICP peaks (B waves) over a long period could eventually cause persisting axonal disturbance and subsequently the symptoms noted in IAHS. PMID:16024885

  2. A computer-based method for comparisons of continuous intracranial pressure recordings within individual cases.

    Science.gov (United States)

    Eide, P K; Fremming, A D

    2003-05-01

    This study assessed two strategies of comparing continuous intracranial pressure (ICP) recordings within individual cases, namely either by calculation of differences in mean ICP or by calculation of differences in numbers of ICP elevations. Continuous ICP recordings before and after cranial surgery were both presented as mean ICP and as numbers of ICP elevations of different levels (20 and 25 mmHg lasting either 0.5 or 1 minute). Since the length of pressure recordings differed somewhat between individuals, the numbers of ICP elevations were standardised by computing the numbers of elevations during a 10 hours period. The ICP recordings were analysed by the Sensometrics Pressure Analyser software. The ICP curves included here were selected from a group of 15 children undergoing calvarial expansion surgery for craniosynostosis, in whom continuous ICP monitoring was performed both before and after surgery as part of the diagnostic workout to rule out lasting intracranial hypertension. After surgery, mean ICP during sleep was reduced by 5 mmHg or more in 5 cases, minimally changed (i.e. 2 mmHg or less) in 6 cases, and variably increased in the other 4 cases. In one of these 4 latter cases, numbers of ICP elevations were increased after surgery, but in all other 14 cases the numbers of ICP elevations were significantly reduced. Reduction of mean ICP by more than 2 mmHg associated with good outcome was observed in 3 of 15 cases (20%), whereas marked and significant reductions in numbers of ICP elevations during sleep combined with good outcome was observed in 12 of 15 cases (80%). Outcome after the 2nd ICP monitoring was more reliably predicted by computing differences in numbers of ICP elevations than by calculation of mean ICP.

  3. Effects of mild hypothermia on patients with lower intracranial pressure following severe brain injury

    Institute of Scientific and Technical Information of China (English)

    王维平; 任海军; 池京洋; 徐福林; 全勇

    2005-01-01

    Objective: To study the effects of mild hypothermia therapy on severe brain-injured patients whose intracranial pressure (ICP) could be maintained below 25 mm Hg.Methods: Forty severe brain-injured patients with ICP below 25 mm Hg were divided randomly into one treatment group (n=20, mild hypothermia therapy) and one control group (n=20, normothermia therapy) to observe the changes of the concentration of excitatory amino acids (glutamate and glycine) and cytokines (interleukin-1β and interleukin-6). Results: There were no significant differences in the daily changes of the concentration of excitatory amino acid and cytokines between two groups. The outcome of two groups had no significant differences. Conclusions: Mild hypothermia has no additional beneficial effects on severe brain-injured patients compared with normothermia therapy if ICP can be maintained below 25 mm Hg by using conventional therapy.

  4. A new approach for investigating intracranial pressure signal: filtering and morphological features extraction from continuous recording.

    Science.gov (United States)

    Calisto, Andrea; Galeano, Massimiliano; Serrano, Salvatore; Calisto, Amedeo; Azzerboni, Bruno

    2013-03-01

    Nowadays, the Intracranial Pressure (ICP) monitoring has become the most common method of investigation for both traumatic and chronic neural pathologies. ICP signals are typically triphasic, that is, in a single waveform, three subpeaks can be identified. This work outlines a new algorithm to identify subpeaks from the ICP recordings and to extract a number of 20 meaningful parameter trends. The validity of the implemented method has been proved through a comparison between the automatic subpeaks identification by the algorithm and the manually marked subpeaks by a neurosurgeon. The automatic marking system has identified subpeaks for the 63.74% (mean value) of pulse waves, providing the position and amplitude of each identified subpeak within a tolerance of ±7 samples. This automatic system provides a feature set to be used by classification software to obtain more precise and easier diagnosis in all those cases that involve brain damages or diseases.

  5. Increased intracranial pressure in myelomeningocele (MMC) patients never shunted: results of a prospective preliminary study.

    Science.gov (United States)

    Iborra, J; Pagès, E; Cuxart, A; Poca, A; Sahuquillo, J

    2000-08-01

    In some young adults non-shunted myelomeningocele (MMC) patients without symptoms or with unspecific clinical findings, moderate or severe stabilised ventriculomegaly are observed in control CT scans. Physicians are then faced with the so-called 'Arrested Hydrocephalus' (AH) syndrome. The present study is part of a prospective protocol in which patients with hydrocephalus associated with MMC and long-term clinical diagnosis of AH were included. To evaluate myelomeningocele patients never shunted with clinical and/or CT scan criteria compatible with AH. Multidisciplinary Spina Bifida Unit in a tertiary university hospital in Barcelona, Spain. Fourteen MMC patients were selected, in all of them, continuous intracranial pressure (ICP) monitoring was performed. Analysis of the ICP records was done using the method described by Borgesen in mmHg. All patients were also studied by intelligence quotient (IQ) testing before and after shunting. The CT in all the study cases showed an Evans ratio Seguridad Social (FISS).

  6. Two levels of the inspired oxygen fraction in propofol-anesthetized dogs with high intracranial pressure: cardiopulmonary function

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    P.C. Ferro Lopes

    2014-10-01

    Full Text Available In the initial stage of traumatic brain injury, the use of 1.0 inspired oxygen fraction (FiO2 is indicated. However, high FiO2 has been correlated with atelectasis. Thus, the effects of FiO2 = 1.0 and FiO2 = 0.6 on the cardiopulmonary function in propofol-anesthetized dogs with high intracranial pressure (ICP were evaluated. Eight dogs were anesthetized on two occasions, receiving, during controlled ventilation, an FiO2 = 1 (G100 or an FiO2 = 0.6 (G60. Propofol was used for induction (10mg.kg-1 followed by a continuous rate infusion (0.6mg.kg-1.minute-1. An increase in the ICP was induced by temporary obliteration of the right jugular vein (OJv 50 minutes after induction of anesthesia. The measurement was taken twenty minutes after OJv (T0 and then at 15-minute intervals (T15 to T60. Alveolar oxygen partial pressure in G60 was lower than in G100 during the whole procedure. Alveolar-arterial oxygen gradient in G100 was greater than in G60 at T0 and at T60. No differences were observed for arterial oxygen partial pressure/inspired oxygen fraction ratio, arterial-to-alveolar oxygen pressure ratio, respiratory index, venous admixture, oxygen delivery, oxygen consumption, oxygen extraction, heart rate, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, cardiac index, stroke index and systemic vascular resistance index. In G100, mean arterial pressure at T0 was higher than at T45. In dogs with high ICP, the cardiopulmonary function was not influenced by the different FiO2 used.

  7. Fluid Shifts Before, During and After Prolonged Space Flight and Their Association with Intracranial Pressure and Visual Impairment

    Science.gov (United States)

    Stenger, Michael; Hargens, Alan; Dulchavsky, Scott

    2014-01-01

    Future human space travel will primarily consist of long duration missions onboard the International Space Station or exploration class missions to Mars, its moons, or nearby asteroids. Current evidence suggests that long duration missions might increase risk of permanent ocular structural and functional changes, possibly due to increased intracranial pressure resulting from a spaceflight-induced cephalad (headward) fluid shift.

  8. Turbine exhaust pressure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Burns, J.M. [Stone & Webster Engineering Corp., Boston, MA (United States); Hernandez, E. [Community Energy Alternatives Inc., Ridgewood, NJ (United States)

    1996-05-01

    This paper discusses the dynamic operating environment in the turbine-condenser steam space and the two sensors, basket tips and guideplates, that have been approved by ASME test codes for measurement of the static pressure within that exhaust region. It defines the rigorous geometry and construction requirements of these sensors in order that they be acceptable for guarantee/acceptance testing. The paper also offers a practical alternative to the classical ASME PTC 6 (Turbine Test Code) basket tip design that is easier to fabricate in the typical utility machine shop. The alternative design makes it less expensive, much faster to construct, and facilitates the drainage of any accumulated condensate. Comparative field tests by PSE&G`s Research and Testing Laboratory conducted in 1995 at the 300 MW Mercer Generating Station, Unit 1 will be described which demonstrate the modified basket tip pressure measurements are statistically indistinguishable from those of the PTC 6 design. Noting that basket tip turbine exhaust static pressure sensors are recommended by all the major U.S. turbine manufacturers, the paper also presents the limited available history of the empirical basket tip and the lack of any documented calibration history related to the accuracy of the guideplate. Finally, based on the success of this one basket tip variation, the paper concludes that other even more suitable designs could be developed by further research.

  9. Research on simulation and experiment of noninvasive intracranial pressure monitoring based on acoustoelasticity effects

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    Wu J

    2013-08-01

    Full Text Available Jun Wu1, Wei He2, Wei-min Chen1, Lian Zhu21Key Laboratory of Optoelectronic Technology and Systems, 2State Key Laboratory of Power Transmission Equipment and System Security and New Technology, Chongqing University, Chongqing, People’s Republic of ChinaAbstract: The real-time monitoring of intracranial pressure (ICP is very important for craniocerebrally critically ill patients, but it is very difficult to realize long-time monitoring for the traditional invasive method, which very easily infects patients. Many noninvasive methods have emerged, but these have not been able to monitor ICP for long periods in real time, and they are not ready for clinical application. In order to realize long-time, online, real-time, noninvasive monitoring for ICP, a new method based on acoustoelasticity of ultrasound is herein proposed. Experimental models were devised to research the new method for experiment and simulation. Polymethyl methacrylate and hydrogel were adopted for the experiment, and their mechanical properties were very close to the real brain. A numerical solution for acoustoelasticity theory was acquired by simulating calculation based on a finite-element method. This was compared to the experimental value. The results showed a consistent match between theoretical solution and experimental value, with maximum error at most 5%. Thus, the effectiveness of the new method was verified. Theoretical and practical foundation is provided for this new method, and it could be used for animal experimentation or clinical testing in further research.Keywords: medical instruments, noninvasive, intracranial pressure, ultrasonic, acoustoelasticity, biomechanics

  10. Sonographic Optic Nerve Sheath Diameter as a Screening Tool for Detection of Elevated Intracranial Pressure

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    Afshin Amini

    2013-12-01

    Full Text Available Introduction: Timely diagnosis and treatment of post traumatic, elevated intracranial pressure (EICP, could reduce morbidity and mortality, as well as improve patients’ outcome. This study is trying to evaluate the diagnostic accuracy of sonographic optic nerve sheath diameter (ONSD in detection of EICP. Methods: Sonographic ONSD of patients with head trauma or cerebrovascular accident suspicious for EICP were evaluated by a trained chief resident of emergency medicine, who was blind to the clinical and brain computed tomography scan (BCT findings of patients. Immediately after ultrasonography, BCT was performed and reported by an expert radiologist without awareness from other results of the patients. Finally, ultrasonographic and BCT findings regarding EICP were compared. To evaluate the ability of sonographic ONSD in predicting the BCT findings and obtain best cut-off level, receiver operating characteristic (ROC curve were used. Sensitivity, specificity, positive predictive value (PPV, negative predictive value (NPV, positive likelihood ratio (PLR, and negative likelihood ratio (NLR of sonographic ONSD in determining of EICP was calculated. P < 0.05 was considered to be statistically significant. Results: There were 222 patients (65.3% male, with mean age of 42.2±19.5 years (range: 16-90 years. BCT showed signs of EICP, in 28 cases (12.6%. The means of the ONSD in the patients with EICP and normal ICP were 5.5 ± 0.56 and 3.93 ± 0.53 mm, respectively (P<0.0001. ROC curve demonstrated that the best cut off was 4.85 mm. Sensitivity, specificity, PPV, NPV, PLR, and NLR of ONSD for prediction of EICP were 96.4%, 95.3%, 72.2%, 98.9%, 20.6, and 0.04, respectively. Conclusion: Sonographic diameter of optic nerve sheath could be considered as an available, accurate, and noninvasive screening tool in determining the elevated intracranial pressure in cases with head trauma or cerebrovascular accident. 

  11. Pseudomigrânea com pleocitose liquórica: monitorização intermitente da pressão intracraniana. Relato de caso Pseudomigraine with CSF hypercytosis: intermittent measurement of the intracranial pressure. Case report

    Directory of Open Access Journals (Sweden)

    Elcio Juliato Piovesan

    2001-06-01

    Full Text Available A pseudomigrânea com pleocitose é uma desordem benigna e auto limitada, caracterizada por sintomas recorrentes, sugestivos de migrânea associada a comprometimento neurológico focal e a alterações no líquido cefalorraquidiano. Monitorizamos a pressão intracraniana em um paciente com este diagnóstico durante os seus períodos sintomáticos e assintomáticos. O paciente foi submetido a três punções lombares com análise citoquímica demonstrando aumento de leucócitos, predominando monomorfonucleares, sem a identificação de agente etiológico. Durante a primeira e a terceira punção lombar o paciente apresentava sintomas neurológicos e cefaléia com características de migrânea, sua pressão intracraniana era de 400 e 440 mmH2O respectivamente. Em um momento assintomático realizamos nova punção lombar ao qual demonstrou pressão intracraniana de 190 mmH20. Os mecanismos fisiopatológicos desta desordem permanecem ainda desconhecidos, existindo algumas evidências que ela esteja relacionada a fenômenos autoimunes, que durante os períodos sintomáticos produzem uma redução no fluxo sangüíneo cerebral assemelhando-se a depressão alastrante. Os achados neste relato de caso sugerem a possibilidade de influência das oscilações da pressão intracraniana nos possíveis mecanismos fisiopatológicos da pseudomigrânea com pleocitose.Pseudomigraine with pleocytosis is a self-limited and rather beningn disorder, characterized by recurrent bouts of migrainous headaches, associated to focal neurological symptoms and to cerebrospinal fluid abnormalities. We have submitted an individual with pseudomigraine to three lumbar punctures. The first and the third lumbar punctures, carried out during symptomatic periods, revealed a cerebrospinal fluid with aseptic lymphomonocytic pleocytosis, and an opening pressure of 400 and 440 mmH2O, respectively. The cerebrospinal fluid pressure measured during an asymptomatic period was normal (190 mm

  12. Reappraisal of the intracranial pressure and cerebrospinal fluid dynamics in patients with the so-called "normal pressure hydrocephalus" syndrome.

    Science.gov (United States)

    Sahuquillo, J; Rubio, E; Codina, A; Molins, A; Guitart, J M; Poca, M A; Chasampi, A

    1991-01-01

    Fifty-four shunt-responsive patients were selected from a prospective protocol directed to study patients with suspected normal pressure hydrocephalus (NPH). Patients with gait disturbances, dementia, non-responsive L-Dopa Parkinsonism, urinary or faecal incontinence and an Evans ratio greater or equal to 0.30 on the CT scan were included in the study. As a part of their work-up all patients underwent intracranial pressure monitoring and hydrodynamic studies using Marmarou's bolus test. According to mean intracranial pressure (ICP) and the percentage of high amplitude B-waves, patients were subdivided in the following categories: 1) Active hydrocephalus (mean ICP above 15 mmHg), which is in fact no tone normal pressure hydrocephalus; 2) Compensated unstable hydrocephalus, when mean ICP was below 15 mmHg and B-waves were present in more than 25% of the total recording time and 3) Compensated stable hydrocephalus when ICP was lower or equal to 15 mmHg and beta waves were present in less than 25% of the total recording time. The majority of the patients in this study (70%) presented continuous high or intermittently raised ICP (active or unstable compensated hydrocephalus group). Mean resistance to outflow of CSF (Rout) was 38.8 mm Hg/ml/min in active hydrocephalus and 23.5 mm Hg/ml/min in the compensated group (Students t-test, p less than 0.05). Higher resistance to outflow was found in patients with obliterated cortical sulci and obliterated Sylvian cisterns in the CT scan. No statistically significant correlation was found when plotting the percentage of beta waves against pressure volume index (PVI), compliance or Rout. An exponential correlation was found when plotting beta waves against the sum of conductance to outflow and compliance calculated by PVI method (r = 0.79). Patients with the so-called normal pressure hydrocephalus syndrome have different ICP and CSF dynamic profiles. Additional studies taking into consideration these differences are necessary

  13. Postural-induced changes in intracranial pressure evaluated non-invasively using the MMS-10 tympanic displacement analyser in healthy volunteers.

    Science.gov (United States)

    Wagner, N; Walsted, A

    2000-01-01

    Inner ear pressure reflects intracranial pressure (ICP) primarily because of the direct communication of perilymph and cerebrospinal fluid (CSF) through the cochlear aqueduct (CA). The MMS-10 tympanic displacement analyser (TDA) is a relatively new device for measuring perilymphatic pressure non-invasively, and thereby also indirectly measuring intracranial pressure. The aim of the present study was to evaluate the use of the TDA in a daily clinical setting. Other aims were to investigate changes in perilymphatic pressure from sitting to lying position in healthy volunteers in two age groups (mean age: 33 years and 50 years) and to compare the patency of the CA in these groups using the MMS-10 TDA. Tympanic membrane displacement (TMD) analyses were performed in the test subjects initially twice in sitting position (test-retest) and then in sitting and supine positions. We found that the MMS-10 TDA is easy to use, and that it gives reproducible values in repeated tests, but with large inter-subject differences. The TMD test showed curves, which, in the whole test group, were more negative in supine position, in accordance with an increasing intracranial and inner ear pressure when lying down. The change from sitting to lying position was larger in the younger group than in the older group. In 11% of the younger group (males) and in 30% of the older group (females), the CA was considered to be non-patent, although the difference was not statistically significant. However, the finding is in keeping with the hypothesis of a greater proportion of patent CA in younger than in older individuals.

  14. Fast circulation of cerebrospinal fluid: an alternative perspective on the protective role of high intracranial pressure in ocular hypertension.

    Science.gov (United States)

    Wostyn, Peter; De Groot, Veva; Van Dam, Debby; Audenaert, Kurt; Killer, Hanspeter Esriel; De Deyn, Peter Paul

    2016-05-01

    As ocular hypertension refers to a condition in which the intraocular pressure is consistently elevated but without development of glaucoma, study of it may provide important clues to factors that may play a protective role in glaucoma. β-amyloid, one of the key histopathological findings in Alzheimer's disease, has been reported to increase by chronic elevation of intraocular pressure in animals with experimentally induced ocular hypertension and to cause retinal ganglion cell death, pointing to similarities in molecular cell death mechanisms between glaucoma and Alzheimer's disease. On the other hand, recent studies have reported that intracranial pressure is higher in patients with ocular hypertension compared with controls, giving rise to the idea that elevated intracranial pressure may provide a protective effect for the optic nerve by decreasing the trans-lamina cribrosa pressure difference. The speculation that the higher intracranial pressure reported in ocular hypertension patients may protect against glaucoma mainly through a lower trans-lamina cribrosa pressure difference remains at least questionable. Here, we present an alternative viewpoint, according to which the protective effect of higher intracranial pressure could be due, at least in part, to a pressure-independent mechanism, namely faster cerebrospinal fluid production leading to increased cerebrospinal fluid turnover with enhanced removal of potentially neurotoxic waste products that accumulate in the optic nerve. This suggests a new hypothesis for glaucoma, which, just like Alzheimer's disease, may be considered then as an imbalance between production and clearance of neurotoxins, including β-amyloid. If confirmed, then strategies to improve cerebrospinal fluid flow are reasonable and could provide a new therapeutic approach for stopping the neurotoxic β-amyloid pathway in glaucoma.

  15. Clinical application of flash visual evoked potential in measurement of intracranial pressure%闪光视觉诱发电位无创检测脑卒中颅内压的临床应用

    Institute of Scientific and Technical Information of China (English)

    吕波; 曾红科; 张秀浓; 孙诚

    2012-01-01

    Objective To determine the normal reference range of intracrariial pressure (ICP)measured by flash visual evoked potential (FVEP),compare the difference between invasive and noninvasive detection,and evaluate the clinical application value. Methods The ICP of health controls and patients with storke were measured by flash visual evoked and 15 patitens with storke were cured by the lateral ventricle puncture and drainage. The levels of ICP in the 15 patients were measured by noninvasive and invasive methods and the difference were compared between the two metods. Results The average noninvasive ICP of health controls was 134.6 ± 48.7mmH20.The 95% confidence interval was 74.8-193.6 mmH20. The average noninvasive ICP of patients with storke was 245.7 ±61.8mmH20 and significant diferences were observed between the two groups(P<0.05). In the 15 cerebral apoplexy patitens,the outcomes of noninvasive ICP were closed to the invasive ICP and the two ways were equivalent with equivalence test. Conclusion There are no diferences between the outcome of FVEP and the ICP by invasive method, FVEP is positively correlated with ICP. Noninvasive measurement of ICP can be used as an good indicator for diagnosis and treatment of cerebral apoplexy.%目的 确定闪光视觉诱发电位无创颅内压检测临床正常参考值范围,并与有创颅内压检测比较测量结果的等效性,评价其指导临床治疗的应用价值.方法 对96例健康人和80颅内压增高的脑卒中患者应用无创颅内压检测,并对15例脑卒中患者行脑室穿刺引流术,比较应用甘露醇治疗前和治疗后30min,60min,120min,180min,240min有创颅内压和无创颅内压变化.结果 96例健康成人无创颅内压平均值为134.6±48.7mmH20,95%可信区间范围为74.8~193.6 mmH20.颅内压增高脑卒中患者无创颅内压平均值为245.7±61.8mmH20,与健康成人检测结果相比,有统计学差异性(P<0.05).15例行脑室穿刺引流术的

  16. Effects of Early Bedside Cycle Exercise on Intracranial Pressure and Systemic Hemodynamics in Critically Ill Patients in a Neurointensive Care Unit.

    Science.gov (United States)

    Thelandersson, Anneli; Nellgård, Bengt; Ricksten, Sven-Erik; Cider, Åsa

    2016-12-01

    Physiotherapy is an important part of treatment after severe brain injuries and stroke, but its effect on intracranial and systemic hemodynamics is minimally investigated. Therefore, the aim of this study was to assess the effects of an early bedside cycle exercise on intracranial and systemic hemodynamics in critically ill patients when admitted to a neurointensive care unit (NICU). Twenty critically ill patients suffering from brain injuries or stroke were included in this study performed in the NICU at Sahlgrenska University Hospital. One early implemented exercise session was performed using a bedside cycle ergometer for 20 min. Intracranial and hemodynamic variables were measured two times before, three times during, and two times after the bedside cycling exercise. Analyzed variables were intracranial pressure (ICP), cerebral perfusion pressure (CPP), mean arterial blood pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO2), cardiac output (CO), stroke volume (SV), and stroke volume variation (SVV). The cycling intervention was conducted within 7 ± 5 days after admission to the NICU. Cycle exercise increased MAP (p = 0.029) and SV (p = 0.003) significantly. After exercise CO, SV, MAP, and CPP decreased significantly, while no changes in HR, SVV, SpO2, or ICP were noted when compared to values obtained during exercise. There were no differences in data obtained before versus after exercise. Early implemented exercise with a bedside cycle ergometer, for patients with severe brain injuries or stroke when admitted to a NICU, is considered to be a clinically safe procedure.

  17. Risk of Microgravity-Induced Visual Impairment and Elevated Intracranial Pressure (VIIP)

    Science.gov (United States)

    Otto, Christian

    2011-01-01

    Eight cases identified, represent 23.5% of the 34 crewmembers flown on the ISS, with inflight visual changes and pre-to-postflight refractive changes. In some cases, the changes were transient while in others they are persistent with varying degrees of visual impairment. (1) Decreased intraocular pressure (IOP) postflight was observed in 3 cases. (2) Fundoscopic exams revealed postflight findings of choroidal folds in 4 cases, optic disc edema in 5 cases and presence of cotton wool spots in 3 cases. (3) Optical coherence tomography (OCT) confirmed findings of choroidal folds and disc edema and documented retinal nerve fiber layer thickening (4 cases). (4) Findings from MRI examinations showed posterior globe flattening (5 cases) and optic nerve sheath distension (6 cases). (5) Opening cerebrospinal fluid (CSF) pressure was elevated in 4 cases postflight reflecting raised intracranial pressure. While the etiology remains unknown, hypotheses speculate that venous insufficiency or hypertension in the brain caused by cephalad fluid shifts during spaceflight are possible mechanisms for ocular changes in astronauts.

  18. Effect of Positive End-Expiratory Pressure on the Sonographic Optic Nerve Sheath Diameter as a Surrogate for Intracranial Pressure during Robot-Assisted Laparoscopic Prostatectomy: A Randomized Controlled Trial

    Science.gov (United States)

    Chin, Ji-Hyun; Kim, Wook-Jong; Lee, Joonho; Han, Yun A.; Lim, Jinwook; Hwang, Jai-Hyun; Cho, Seong-Sik

    2017-01-01

    Background Positive end-expiratory pressure (PEEP) can increase intracranial pressure. Pneumoperitoneum and the Trendelenburg position are associated with an increased intracranial pressure. We investigated whether PEEP ventilation could additionally influence the sonographic optic nerve sheath diameter as a surrogate for intracranial pressure during pneumoperitoneum combined with the Trendelenburg position in patients undergoing robot-assisted laparoscopic prostatectomy. Methods After anesthetic induction, 38 patients were randomly allocated to a low tidal volume ventilation (8 ml/kg) without PEEP group (zero end-expiratory pressure [ZEEP] group, n = 19) or low tidal volume ventilation with 8 cmH2O PEEP group (PEEP group, n = 19). The sonographic optic nerve sheath diameter was measured prior to skin incision, 5 min and 30 min after pneumoperitoneum and the Trendelenburg position, and at the end of surgery. The study endpoint was the difference in the sonographic optic nerve sheath diameter 5 min after pneumoperitoneum and the Trendelenburg position between the ZEEP and PEEP groups. Results Optic nerve sheath diameters 5 min after pneumoperitoneum and the Trendelenburg position did not significantly differ between the groups [least square mean (95% confidence interval); 4.8 (4.6–4.9) mm vs 4.8 (4.7–5.0) mm, P = 0.618]. Optic nerve sheath diameters 30 min after pneumoperitoneum and the Trendelenburg position also did not differ between the groups [least square mean (95% confidence interval); 4.5 (4.3–4.6) mm vs 4.5 (4.4–4.6) mm, P = 0.733]. Conclusions An 8 cmH2O PEEP application under low tidal volume ventilation does not induce an increase in the optic nerve sheath diameter during pneumoperitoneum combined with the steep Trendelenburg position, suggesting that there might be no detrimental effects of PEEP on the intracranial pressure during robot-assisted laparoscopic prostatectomy. Trial Registration ClinicalTrial.gov NCT02516566 PMID:28107408

  19. Clinical application of invasive intracranial pressure monitoring after severe traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Xia LI

    2011-12-01

    Full Text Available Objective The current study aims to investigate the effects of different intracranial pressure(ICP monitoring means on the prognosis of severe traumatic brain injury,and to determine the significance of all kinds of intracranial pressure monitoring methods for treating severe traumatic brain injury clinically.Methods From January 2009 to June 2010,a total of 201 cases of severe traumatic brain injury(STBI who received operation treatment were collected and divided into A,B,and C groups based on the positions of the ICP probes and the placement methods.ICP monitoring probes were placed in the ventricle of the brain,parenchyma,or under the putamen,on the basis of the routine operation.Lumbar puncture was done once a day for three to seven days after operation.The Ncurolymph pressure and ICP value that are simultaneously shown in the ICP monitoring device were recorded to calculate the difference between them and to conduct comparison among the groups.The corresponding dehydration treatment was made based on the ICP value after operation to record the duration of use and dosage of the dehydrating agent,operation time,occurrence of all kinds of complications,and the prognosis of patients,and to create a comparison among the groups.Results The different values between the ICP monitoring values and ncurolymph pressure in the A,B,and C groups were 22.4±3.6,20.8±4.1,and 12.3±11.5 mmH2O,respectively. The dosage and durationof use of mannitol in group C were significantly higher than those in groups A and B(P < 0.01,whereas the incidence of pulmonary infection and electrolyte disturbance in group C was higher than those in groups A and B(P < 0.01.However,no significant difference of prognosis was observed among the three groups.The operating duration of group A was significantly longer than those of groups B and C(P < 0.01.However,the overall prognosis of the patients in the three groups had no significant difference.The operation time of group A was

  20. Increased Intracranial Pressure and Visual Impairment Associated with Long-Duration Spaceflight

    Science.gov (United States)

    Marshall-Bowman, Karina

    2011-01-01

    Although humans have been flying in space since the 1960s, more recent missions have revealed a new suite of physiological adaptations and consequences of space flight. Notably, 60% of long-duration crewmembers (ISS/MIR) and >25% of short-duration (Shuttle) crewmembers have reported subjective degradation in vision (based on debrief comments) (Gibson 2011). Decreased near-visual acuity was demonstrated in 46% of ISS/Mir and 21% of Shuttle crewmembers, resulting in a shift of up to 1-2 diopters in their refractive correction. It is likely that the recently revealed ophthalmic changes have been present since the first days of human space flight, but have been overlooked or attributed to other causations. The reported changes in vision have occurred at various time points throughout missions, with ranging degrees of visual degradation. Although some cases resolved upon return to Earth, several astronauts have not regained preflight visual acuity, indicating that the damage may be permanent. While observing these changes over the years, without other overt symptomology and with the given age range of the flying population, this has largely been attributed to an expected hyperopic shift due to aging. However, the availability of onboard analysis techniques, including visual acuity assessments, retinal imagery, and ultrasounds of the eye and optic nerve tracts, along with more detailed post-flight techniques, has led to the recent recognition of a wider syndrome. Along with vision changes, findings include flattening of the globe, swelling of the optic disc (papilledema), choroidal folds in the retina, swelling of the optic nerve sheath, and visual field defects. It is widely hypothesized that this constellation of findings may be explained by an elevation of intracranial pressure (ICP). Out of the 60% of long-duration astronauts that have reported a subjective degradation in vision, a subset (currently 10 astronauts) have developed this syndrome. The National

  1. Intracranial pressure pulse waveform correlates with aqueductal cerebrospinal fluid stroke volume.

    Science.gov (United States)

    Hamilton, Robert; Baldwin, Kevin; Fuller, Jennifer; Vespa, Paul; Hu, Xiao; Bergsneider, Marvin

    2012-11-01

    This study identifies a novel relationship between cerebrospinal fluid (CSF) stroke volume through the cerebral aqueduct and the characteristic peaks of the intracranial pulse (ICP) waveform. ICP waveform analysis has become much more advanced in recent years; however, clinical practice remains restricted to mean ICP, mainly due to the lack of physiological understanding of the ICP waveform. Therefore, the present study set out to shed some light on the physiological meaning of ICP morphological metrics derived by the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm by investigating their relationships with a well defined physiological variable, i.e., the stroke volume of CSF through the cerebral aqueduct. Seven patients received both overnight ICP monitoring along with a phase-contrast MRI (PC-MRI) of the cerebral aqueduct to quantify aqueductal stroke volume (ASV). Waveform morphological analysis of the ICP signal was performed by the MOCAIP algorithm. Following extraction of morphological metrics from the ICP signal, nine temporal ICP metrics and two amplitude-based metrics were compared with the ASV via Spearman's rank correlation. Of the nine temporal metrics correlated with the ASV, only the width of the P2 region (ICP-Wi2) reached significance. Furthermore, both ICP pulse pressure amplitude and mean ICP did not reach significance. In this study, we showed the width of the second peak (ICP-Wi2) of an ICP pulse wave is positively related to the volume of CSF movement through the cerebral aqueduct. This finding is an initial step in bridging the gap between ICP waveform morphology research and clinical practice.

  2. Complications corner: Anterior thoracic disc surgery with dural tear/CSF fistula and low-pressure pleural drain led to severe intracranial hypotension

    Directory of Open Access Journals (Sweden)

    Eline A Oudeman

    2015-01-01

    Conclusion: Severe neurological deterioration occurring after thoracic decompressive surgery may rarely be attributed to intracranial hypotension due to a subarachnoid-pleural fistula. Patients should be treated with external lumbar drainage of cerebrospinal fluid for 3-5 days rather than a low-pressure pleural drain to avoid the onset of intracranial hypotension leading to symptomatic subdural hematomas.

  3. Serum IL-6: a candidate biomarker for intracranial pressure elevation following isolated traumatic brain injury

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    Ward Norman H

    2010-03-01

    Full Text Available Abstract Background Increased intracranial pressure (ICP is a serious, life-threatening, secondary event following traumatic brain injury (TBI. In many cases, ICP rises in a delayed fashion, reaching a maximal level 48-96 hours after the initial insult. While pressure catheters can be implanted to monitor ICP, there is no clinically proven method for determining a patient's risk for developing this pathology. Methods In the present study, we employed antibody array and Luminex-based screening methods to interrogate the levels of inflammatory cytokines in the serum of healthy volunteers and in severe TBI patients (GCS≤8 with or without incidence of elevated intracranial pressure (ICP. De-identified samples and ELISAs were used to confirm the sensitivity and specificity of IL-6 as a prognostic marker of elevated ICP in both isolated TBI patients, and polytrauma patients with TBI. Results Consistent with previous reports, we observed sustained increases in IL-6 levels in TBI patients irrespective of their ICP status. However, the group of patients who subsequently experienced ICP ≥ 25 mm Hg had significantly higher IL-6 levels within the first 17 hours of injury as compared to the patients whose ICP remained ≤20 mm Hg. When blinded samples (n = 22 were assessed, a serum IL-6 cut-off of 128 pg/ml correctly identified 85% of isolated TBI patients who subsequently developed elevated ICP, and values between these cut-off values correctly identified 75% of all patients whose ICP remained ≤20 mm Hg throughout the study period. In contrast, the marker had no prognostic value in predicting elevated ICP in polytrauma patients with TBI. When the levels of serum IL-6 were assessed in patients with orthopedic injury (n = 7 in the absence of TBI, a significant increase was found in these patients compared to healthy volunteers, albeit lower than that observed in TBI patients. Conclusions Our results suggest that serum IL-6 can be used for the

  4. Monitoring intracranial pressure utilizing a novel pattern of brain multiparameters in the treatment of severe traumatic brain injury

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    Sun H

    2016-06-01

    Full Text Available Hong-tao Sun,1,* Maohua Zheng,2,* Yanmin Wang,1 Yunfeng Diao,1 Wanyong Zhao,1 Zhengjun Wei1 1Sixth Department of Neurosurgery, Affiliated Hospital of Logistics University of People’s Armed Police Force, Tianjin, 2Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, People’s Republic of China *These authors contributed equally to this work Abstract: The aim of the study was to evaluate the clinical value of multiple brain parameters on monitoring intracranial pressure (ICP procedures in the therapy of severe traumatic brain injury (sTBI utilizing mild hypothermia treatment (MHT alone or a combination strategy with other therapeutic techniques. A total of 62 patients with sTBI (Glasgow Coma Scale score <8 were treated using mild hypothermia alone or mild hypothermia combined with conventional ICP procedures such as dehydration using mannitol, hyperventilation, and decompressive craniectomy. The multiple brain parameters, which included ICP, cerebral perfusion pressure, transcranial Doppler, brain tissue partial pressure of oxygen, and jugular venous oxygen saturation, were detected and analyzed. All of these measures can control the ICP of sTBI patients to a certain extent, but multiparameters associated with brain environment and functions have to be critically monitored simultaneously because some procedures of reducing ICP can cause side effects for long-term recovery in sTBI patients. The result suggested that multimodality monitoring must be performed during the process of mild hypothermia combined with conventional ICP procedures in order to safely target different clinical methods to specific patients who may benefit from an individual therapy. Keywords: mild hypothermia treatment, cerebral perfusion pressure, brain tissue partial pressure of oxygen

  5. Effect of propofol and thiopentone on intracranial pressure and cerebral perfusion pressure in patients undergoing elective craniotomy - a comparative study

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    Sankari Santra

    2007-01-01

    Full Text Available Advantages and disadvantages of newer agent like propofol need to be evaluated with time tested inducing drug - thiopentone in neuroanaesthesia. The aim of the study was to compare effects of propofol with thiopentone on intracranial pressure, cerebral perfusion pressure and haemodynamics during induction in neurosurgical pa-tients. Fifty adult patients of ASA grade I& II scheduled for elective craniotomy were randomly assigned to receive induction of anaesthesia with either propofol 1.5-2.5 mg.kg -1 i.v. (Group A, n=25 or thiopentone 4-5 mg.kg -1 , i.v. (Group B, n=25. Vecuronium bromide 0.1 mg.kg -1 i.v. was used as intubating muscle relaxant. Both groups received fentanyl 2 pg.kg -1 i.v., lidocaine(preservative free 1.5 mg.kg -1 i.v. and supplementary dose of same inducing agent before intubation. Changes in mean arterial pressure (MAP, cerebrospinal fluid pressure (CSFP, cerebral perfusion pressure (CPP and heart rate (HR were noted during induction and endotracheal intubation. On statistical analysis it was found that CSFP decreased significantly (P< 0.001 in both groups after induction but endotracheal intubation did not provoke any significant rise in CSFP. Maximum decrease of CSFP was 35.26% in Group A and 35.20% in Group B. Fall in MAP was more significant in Group A (P< 0.001, as a result CPP was significantly less in Group A than in Group B. The lowest mean CPP (71.12±5.86 mm Hg was observed 2 minutes after induction dose in Group A when maximum drop in MAP occurred. Heart rate did not change significantly in Group A but in Group B fluctuation of heart rate was more.

  6. Intracerebral abscess associated with the Camino intracranial pressure monitor: case report and review of the literature.

    Science.gov (United States)

    Morton, Ryan; Lucas, Timothy H; Ko, Andrew; Browd, Samuel R; Ellenbogen, Richard G; Chesnut, R M

    2012-07-01

    Intracranial pressure (ICP) monitoring is a mainstay in the management of traumatic brain injury. Large investigations have validated the safety and efficacy of ICP monitors in comatose patients. Clinically relevant infections are extremely rare and cerebral abscess has never been reported with the Camino device. We describe an exceptional case of a life-threatening intracerebral abscess from an intraparenchymal ICP monitor. A 35-month-old child required 7 days of ICP monitoring after a fall from a 2-story window. His hospital course was complicated by severe airway edema treated, in part, with high-dose corticosteroid therapy for a total of 10 days. Two weeks later, the patient deteriorated acutely owing to a large intracerebral abscess under the previous ICP monitor site. Urgent craniotomy with evacuation of the abscess was performed on 2 separate occasions. Cultures grew methicillin-sensitive Staphylococcus aureus, which was treated with long-term antibiotics. At the 3-month follow-up, the patient was meeting age-appropriate milestones without focal deficits. To the best of our knowledge, this is the first report describing an intracerebral abscess as a complication from an intraparenchymal pressure monitor. Corticosteroid therapy may have constituted an independent risk factor for the ICP monitor--associated infection, as well as reinsertion of the ICP monitoring device at the same site. That this is the first reported parenchymal infectious complication underscores the safety of this device with respect to infection. When reinsertion of a parenchymal monitor is considered, a new site should be chosen.

  7. Differences in quantitative characteristics of intracranial pressure in hydrocephalic children treated surgically or conservatively.

    Science.gov (United States)

    Eide, Per Kristian; Due-Tønnessen, Bernt; Helseth, Eirik; Lundar, Tryggve

    2002-06-01

    This study reports the results of quantitative analysis of continuous intracranial pressure (ICP) recordings in 33 hydrocephalic children. The aim of the study was to compare the exact numbers of increases in ICP during sleep or the awake state in hydrocephalic children who were treated either surgically or conservatively. At the time of ICP monitoring, the ICP curves were assessed by the calculation of mean ICP and visual inspection for the detection of plateau waves. Quantitative analysis was performed with the software Sensometrics Pressure Analyser, which presented the ICP curve as a matrix of numbers of ICP elevations of different levels (20-40 mm Hg) and durations (0.5-20 min). In each case, the numbers of ICP elevations were standardized to 10 h of recording time, providing the opportunity for comparisons of ICP curves between individuals. Compared to the surgery group, there was a rather high number of ICP elevations of 20 mm Hg of various durations in the nonsurgery group, e.g. ICP elevations of 20 mm Hg lasting 10 min occurred in 13 of 19 children (68%) in the nonsurgery group. There was no apparent relationship between ICP and age or between the size of the cerebral ventricles and ICP. In children with hydrocephalus, the presentation of the ICP data as a matrix of ICP elevations of different levels and durations may enhance the informative value of continuous ICP monitoring, as compared to the calculation of mean ICP and visual detection of plateau waves. Copyright 2002 S. Karger AG, Basel

  8. A physical framework for implementing virtual models of intracranial pressure and cerebrospinal fluid dynamics in hydrocephalus shunt testing.

    Science.gov (United States)

    Venkataraman, Pranav; Browd, Samuel R; Lutz, Barry R

    2016-09-01

    OBJECTIVE The surgical placement of a shunt designed to resolve the brain's impaired ability to drain excess CSF is one of the most common treatments for hydrocephalus. The use of a dynamic testing platform is an important part of shunt testing that can faithfully reproduce the physiological environment of the implanted shunts. METHODS A simulation-based framework that serves as a proof of concept for enabling the application of virtual intracranial pressure (ICP) and CSF models to a physical shunt-testing system was engineered. This was achieved by designing hardware and software that enabled the application of dynamic model-driven inlet and outlet pressures to a shunt and the subsequent measurement of the resulting drainage rate. RESULTS A set of common physiological scenarios was simulated, including oscillations in ICP due to respiratory and cardiac cycles, changes in baseline ICP due to changes in patient posture, and transient ICP spikes caused by activities such as exercise, coughing, sneezing, and the Valsalva maneuver. The behavior of the Strata valve under a few of these physiological conditions is also demonstrated. CONCLUSIONS Testing shunts with dynamic ICP and CSF simulations can facilitate the optimization of shunts to be more failure resistant and better suited to patient physiology.

  9. Management of patients with severe traumatic brain injury guided by intraventricular intracranial pressure monitoring: a report of 136 cases

    Institute of Scientific and Technical Information of China (English)

    ZENG Tao; GAO Liang

    2010-01-01

    Objective:To evaluate the effect of the treatment modality guided by intraventricular intracranial pressure (ICP) monitoring on patients with severe traumatic brain injury (TBI).Methods:The clinical data of a group of 136 severely brain-injured patients admitted to Shanghai Neurosurgical Emergency Center from December 2004 to February 2006 were studied.Results:The intraventricular ICP monitor was placed in all the 136 patients via Kocher's pathway, Paine's pathway or intraoperative opened ventricle. In this series, the probe was placed during the procedure of craniotomy in 98 patients; for other 38 patients, the probe was placed initially to measure or to monitor ICE A stepwise protocol targeting at ICP control (≤20 mm Hg) and optimal cerebral perfusion pressure (CPP) maintenance (60-90 mm Hg) was deployed.Among them, 76 patients survived with good recovery, 14 with moderate disability, 24 with severe disability, 10 with vegetative state, and 12 died. Complications associated with intraventricular ICP monitoring included hemorrhage and infection. Hemorrhage occurred in 1 patient and infection in 5 patients. There were no unacceptable complications related to ICP monitoring.Conclusions:Ventricular access for ICP monitoring can be safely and accurately achieved. ICP monitoring via ventriculostomy may facilitate an early and accurate intervention for severely brain-injured patients. The intraventricular ICP monitoring is a low-risk procedure and can yield great benefits for management of patients with severe TBI.

  10. Research on simulation and experiment of noninvasive intracranial pressure monitoring based on acoustoelasticity effects.

    Science.gov (United States)

    Wu, Jun; He, Wei; Chen, Wei-Min; Zhu, Lian

    2013-01-01

    The real-time monitoring of intracranial pressure (ICP) is very important for craniocerebrally critically ill patients, but it is very difficult to realize long-time monitoring for the traditional invasive method, which very easily infects patients. Many noninvasive methods have emerged, but these have not been able to monitor ICP for long periods in real time, and they are not ready for clinical application. In order to realize long-time, online, real-time, noninvasive monitoring for ICP, a new method based on acoustoelasticity of ultrasound is herein proposed. Experimental models were devised to research the new method for experiment and simulation. Polymethyl methacrylate and hydrogel were adopted for the experiment, and their mechanical properties were very close to the real brain. A numerical solution for acoustoelasticity theory was acquired by simulating calculation based on a finite-element method. This was compared to the experimental value. The results showed a consistent match between theoretical solution and experimental value, with maximum error at most 5%. Thus, the effectiveness of the new method was verified. Theoretical and practical foundation is provided for this new method, and it could be used for animal experimentation or clinical testing in further research.

  11. Continuous ventricular cerebrospinal fluid drainage with intracranial pressure monitoring for management of posttraumatic diffuse brain swelling

    Directory of Open Access Journals (Sweden)

    Almir Ferreira de Andrade

    2011-02-01

    Full Text Available BACKGROUND: Ventricular drainage has played an important role in the management of traumatic brain-injured patients. The aim of the present study was describe outcomes in a series of 57 patients with diffuse brain swelling underwent to intracranial pressure (ICP monitoring. METHOD: Fifty-eight patients with diffuse posttraumatic brain swelling, were evaluated prospectively. The Glasgow Coma Scale (GCS scores of patients varied from 4 to 12. Patients groups divided according to GCS and age. Patient neurological assessment was classified as favorable, unfavorable, and death. RESULTS: Mechanisms of injury were vehicle accidents in 72.4% and falls in 15.6%. 54% of patients had GCS scores between 6 and 8. There were no statistical differences, regarding outcome, between groups separated by age. In the adults group (n=47, 44.7% evolved favorably. CONCLUSION: Our results indicate a poor prognosis in patients with brain swelling. We believe that continuous ventricular CSF drainage with ICP monitoring is a simple method as an adjunct in the management of these patients.

  12. Intensive care management of head injury patients without routine intracranial pressure monitoring

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    Santhanam R

    2007-01-01

    Full Text Available Background: Head injury contributes significantly to mortality and morbidity in India. Evaluation of the available trauma care facilities may help improve outcome. Aim: To evaluate the factors influencing the mortality of patients with head injury who had intensive care management and evolve strategies to improve outcome. Setting and Design: Retrospective study in a tertiary hospital where intracranial pressure monitoring (ICPM is not routinely practiced. Materials and Methods: All patients with head injury managed in the intensive care unit in a two-year period were included. The factors evaluated were age, vital signs, Glasgow Coma scale score (GCS at admission, pupillary light reflex (PR, oculocephalic reflex (OCR, hemodynamic stability, computerized tomography (CT findings, diabetes mellitus, anemia, infections and abnormalities of serum sodium. Results: We analyzed 208 patients (202 without ICPM. In-hospital mortality was 64 (31%. Only 24 (11.5% patients were admitted within one hour of injury, while one-third arrived after six hours. The clinical factors (at admission that influenced mortality included age, GCS, PR, OCR and diastolic blood pressure (DBP. Effacement of the basal cisterns in the initial and repeat CT scans, hyperglycemia, hemodynamic instability and serum sodium imbalances were associated with higher mortality. The independent predictors of mortality by logistic regression were initial GCS, DBP, hemodynamic instability and effacement of cisterns on repeat CT. Conclusions: Mortality following head injury is high. Pre-hospital emergency medical services are disorganized. The key to reducing mortality within the limitations of our current trauma system is maintenance of DBP>70 mmHg and SBP> 90 mmHg from the time of first contact.

  13. Quantitative analysis of continuous intracranial pressure recordings in symptomatic patients with extracranial shunts.

    Science.gov (United States)

    Eide, P K

    2003-02-01

    To explore the outcome of management of possible shunt related symptoms using intracranial pressure (ICP) monitoring, and to identify potential methodological limitations with the current strategies of ICP assessment. The distribution of persistent symptoms related to extracranial shunt treatment was compared before and after management of shunt failure in 69 consecutive hydrocephalic cases. Management was heavily based on ICP monitoring (calculation of mean ICP and visual determination of plateau waves). After the end of patient management, all ICP curves were re-evaluated using a quantitative method and software (Sensometrics pressure analyser). The ICP curves were presented as a matrix of numbers of ICP elevations (20 to 35 mm Hg) or depressions (-10 to -5 mm Hg) of different durations (0.5, 1, or 5 minutes). The numbers of ICP elevations/depressions standardised to 10 hours recording time were calculated to allow comparisons of ICP between individuals. After ICP monitoring and management of the putative shunt related symptoms, the symptoms remained unchanged in as many as 58% of the cases, with the highest percentages in those patients with ICP considered normal or too low at the time of ICP monitoring. The quantitative analysis revealed a high frequency of ICP elevations (20 to 35 mm Hg lasting 0.5 to 1 minute) and ICP depressions (-10 to -5 mm Hg lasting 0.5, 1, or 5 minutes), particularly in patients with ICP considered normal. The value of continuous ICP monitoring with ICP analysis using current criteria appears doubtful in the management of possible shunt related symptoms. This may reflect limitations in the strategies of ICP analysis. Calculation of the exact numbers of ICP elevations and depressions may provide a more accurate description of the ICP profile.

  14. Optic Nerve Sonography in the Diagnostic Evaluation of Pseudopapilledema and Raised Intracranial Pressure: A Cross-Sectional Study

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    Masoud Mehrpour

    2015-01-01

    Full Text Available Introduction. Differentiating pseudopapilledema from papilledema which is optic disk edema and a result of increased ICP (intracranial pressure is important and can be done with noninvasive methods like orbital ultrasound examination. Method. This was a cross-sectional study in which patients with optic nerve head swelling were referred for LP exam after optic nerve head swelling diagnosis confirmation and having normal brain imaging (CT scan. Before LP (lumbar puncture exam the patients were referred for optic nerve ultrasound test of both eyes. Results. Considering 5.7 mm as the upper limit for normal ONSD (optic nerve sheath diameter, sensitivity and negative predictive value of optic sonography in diagnosis of pseudopapilledema are 100% for both eyes. Calculated accuracy validity of ONSD measurement in detecting pseudopapilledema is 90% for the right eye and 87% for the left eye. Conclusion. Our study demonstrated a close correlation between optic nerve sheath dilation on ocular ultrasound and evidence of elevated ICP with optic disk swelling. With the aid of noninvasive diagnostic tests we can avoid unnecessary concerns along with expensive and invasive neurological investigations while targeting the correct diagnosis in bilateral optic disk swelling. Our study showed optic nerve sonography as a reliable diagnostic method for further usage.

  15. [Measurement of arterial pressure].

    Science.gov (United States)

    Rorive, G

    1998-03-01

    The casual determination of blood pressure remains the basis of the diagnosis of arterial hypertension and the criteria for usefulness of drug therapy. The reference values usually in use concern determinations by the doctor in very well defined conditions, rest, size of the bladder, etc.... The poor reproductibility of the determinations made by the doctor in casual conditions has produced a large interest for new approaches: autodetermination by the patient at home, and ambulatory blood pressure determinations using automatic devices. These new approaches have their own reference values, specific indications and limitations.

  16. [Possibilities of data acquisition, recording and processing based on the system for continuous intracranial pressure and cerebral perfusion pressure monitoring designed at the Department of Neurosurgery of the Jagiellonian University in Cracow].

    Science.gov (United States)

    Czepko, Ryszard; Cieślicki, Krzysztof; Niedźwiedzki, Jerzy; Libionka, Witold; Pietraszko, Wojciech

    2005-01-01

    To describe computer system for intracranial pressure (ICP) monitoring and for infusion testing (IT), and to present current possibilities of analysis of cerebrospinal fluid (CSF) pressure signal. Computer system for pressure signal measurement and acquisition consists of three sensors: for ICP, infusion pressure during IT, and blood pressure measurements. Electric signal from the sensors is transmitted to Temed RMN-201M cardiomonitor, and next after enhancement is subjected to Data Shuttle DS-12-8-5B-AO analog to digital converter. Digital output signal is recorded and analysed'on standard personal computer. Original Windows-compatible software was developed to control the system. The program consists of three blocs: configuration, measurement and readout, and enables selection of voltage range for each of the signal channels, measurement resolution, sampling frequency, calibration and zeroing of the sensors, visualisation of pressure signals on graph, data storage in text format and automatic analysis of IT. Main characteristics of the system include: high sampling frequency (up to 500 Hz), simultaneous data recording from all signal channels, and access to terminal cistern with one puncture needle on IT. Laboratory and clinical tests confirmed high precision of the developed system. ICP CURVE ANALYSIS: The developed software allows for evaluation of the main parameters, of CSF dynamics, prediction of IT course before a steady state is reached as well as spectral analysis of pressure signal. Computer measurement system developed at our department is clinically useful and allows for high precision signal acquisition necessary for advanced scientific analyses of hydrocephalus and intracranial pressure.

  17. Brain hypoxanthine concentration correlates to lactate/pyruvate ratio but not intracranial pressure in patients with acute liver failure

    DEFF Research Database (Denmark)

    Bjerring, Peter Nissen; Hauerberg, John; Jørgensen, Linda;

    2010-01-01

    The pathogenesis of cerebral edema in acute liver failure is suggested, in in vitro and animal studies, to involve a compromised oxidative metabolism with a decrease in cerebral ATP levels and an increase in purine concentrations. In this study we hypothesize that the cerebral concentrations...... of hypoxanthine, inosine, and lactate/pyruvate (LP) ratio are increased and correlated in patients with acute liver failure. Furthermore, we expect the purines and L/P ratio to correlate with intracranial pressure (ICP) (positively), and cerebral perfusion pressure (CPP) (negatively)....

  18. Effect of blood transfusion, dopamine, or normal saline on neurogenic shock secondary to acutely raised intracranial pressure.

    Science.gov (United States)

    Rahimifar, M; Tator, C H; Shanlin, R J; Sole, M J

    1989-06-01

    An experimental model to simulate acutely raised intracranial pressure due to a rapidly expanding intracranial space-occupying lesion was used to produce neurogenic shock. Forty-one rats in neurogenic shock (defined as a mean systemic arterial pressure (SAP) of less than 60 mm Hg) were subjected to various treatments to increase the mean SAP to a level of more than 80 mm Hg. The control group with neurogenic shock received no treatment, and the six treatment groups received infusions of: whole blood, packed cells, plasma, normal saline, dopamine, or a combination of dopamine and saline. Detrimental effects were observed after transfusion of packed cells or whole blood, which caused further deterioration of mean SAP. Although dopamine or the combination of dopamine and saline were both effective (p = 0.0001) for reversing hypotension, the combination was the most effective. If this rat paradigm correlates with human disease, these results indicate that, in the absence of hypovolemia, neurogenic shock due to acute intracranial hypertension should be treated with a combined transfusion of dopamine and normal saline, but not blood since the latter could have a detrimental effect.

  19. Intracranial pressure monitoring, cerebral perfusion pressure estimation, and ICP/CPP-guided therapy: a standard of care or optional extra after brain injury?

    Science.gov (United States)

    Kirkman, M A; Smith, M

    2014-01-01

    Measurement of intracranial pressure (ICP) and mean arterial pressure (MAP) is used to derive cerebral perfusion pressure (CPP) and to guide targeted therapy of acute brain injury (ABI) during neurointensive care. Here we provide a narrative review of the evidence for ICP monitoring, CPP estimation, and ICP/CPP-guided therapy after ABI. Despite its widespread use, there is currently no class I evidence that ICP/CPP-guided therapy for any cerebral pathology improves outcomes; indeed some evidence suggests that it makes no difference, and some that it may worsen outcomes. Similarly, no class I evidence can currently advise the ideal CPP for any form of ABI. 'Optimal' CPP is likely patient-, time-, and pathology-specific. Further, CPP estimation requires correct referencing (at the level of the foramen of Monro as opposed to the level of the heart) for MAP measurement to avoid CPP over-estimation and adverse patient outcomes. Evidence is emerging for the role of other monitors of cerebral well-being that enable the clinician to employ an individualized multimodality monitoring approach in patients with ABI, and these are briefly reviewed. While acknowledging difficulties in conducting robust prospective randomized studies in this area, such high-quality evidence for the utility of ICP/CPP-directed therapy in ABI is urgently required. So, too, is the wider adoption of multimodality neuromonitoring to guide optimal management of ICP and CPP, and a greater understanding of the underlying pathophysiology of the different forms of ABI and what exactly the different monitoring tools used actually represent.

  20. Semi-supervised detection of intracranial pressure alarms using waveform dynamics.

    Science.gov (United States)

    Scalzo, Fabien; Hu, Xiao

    2013-04-01

    Patient monitoring systems in intensive care units (ICU) are usually set to trigger alarms when abnormal values are detected. Alarms are generated by threshold-crossing rules that lead to high false alarm rates. This is a recognized issue that causes alarm fatigue, waste of human resources, and increased patient risks. Recently developed smart alarm models require alarms to be validated by experts during the training phase. The manual annotation process involved is time-consuming and virtually impossible to achieve for the thousands of alarms recorded in the ICU every week. To tackle this problem, we investigate in this study if the use of semi-supervised learning methods, that can naturally integrate unlabeled data samples in the model, can be used to improve the accuracy of the alarm detection. As a proof of concept, the detection system is evaluated on intracranial pressure (ICP) signal alarms. Specific morphological and trending features are extracted from the ICP signal waveform to capture the dynamic of the signal prior to alarms. This study is based on a comprehensive dataset of 4791 manually labeled alarms recorded from 108 neurosurgical patients. A comparative analysis is provided between kernel spectral regression (SR-KDA) and support vector machine (SVM) both modified for the semi-supervised setting. Results obtained during the experimental evaluations indicate that the two models can significantly reduce false alarms using unlabeled samples; especially in the presence of a restrained number of labeled examples. At a true alarm recognition rate of 99%, the false alarm reduction rates improved from 9% (supervised) to 27% (semi-supervised) for SR-KDA, and from 3% (supervised) to 16% (semi-supervised) for SVM.

  1. Variation in intracranial pressure monitoring and outcomes in pediatric traumatic brain injury.

    Science.gov (United States)

    Bennett, Tellen D; Riva-Cambrin, Jay; Keenan, Heather T; Korgenski, E Kent; Bratton, Susan L

    2012-07-01

    To describe between-hospital and patient-level variation in intracranial pressure (ICP) monitoring and to evaluate ICP monitoring in association with hospital features and outcome in children with traumatic brain injury (TBI). Retrospective cohort study. SETTING Children's hospitals participating in the Pediatric Health Information System database (January 2001 to June 2011). Children (aged head Abbreviated Injury Scale scores of at least 3 who were ventilated for at least 96 consecutive hours or who died in the first 4 days after hospital admission. Monitoring of ICP. A total of 4667 children met the study criteria. Hospital mortality was 41% (n = 1919). Overall, 55% of patients (n = 2586) received ICP monitoring. Expected hospital ICP monitoring rates after adjustment for patient age, cardiac arrest, inflicted injury, craniotomy or craniectomy, head Abbreviated Injury Scale score, and Injury Severity Score were 47% to 60%. Observed hospital ICP monitoring rates were 14% to 83%. Hospitals with more observed ICP monitoring, relative to expected, and hospitals with higher patient volumes had lower rates of mortality or severe disability. After adjustment for between-hospital variation and patient severity of injury, ICP monitoring was independently associated with age 1 year and older (odds ratio, 3.1; 95% CI, 2.5-3.8) vs age younger than 1 year. There was significant between-hospital variation in ICP monitoring that cannot be attributed solely to differences in case mix. Hospitals that monitor ICP more frequently and hospitals with higher patient volumes had better patient outcomes. Infants with TBI are less likely to receive ICP monitoring than are older children.

  2. Analyses of cerebral microdialysis in patients with traumatic brain injury: relations to intracranial pressure, cerebral perfusion pressure and catheter placement

    Directory of Open Access Journals (Sweden)

    Wanecek Michael

    2011-03-01

    Full Text Available Abstract Background Cerebral microdialysis (MD is used to monitor local brain chemistry of patients with traumatic brain injury (TBI. Despite an extensive literature on cerebral MD in the clinical setting, it remains unclear how individual levels of real-time MD data are to be interpreted. Intracranial pressure (ICP and cerebral perfusion pressure (CPP are important continuous brain monitors in neurointensive care. They are used as surrogate monitors of cerebral blood flow and have an established relation to outcome. The purpose of this study was to investigate the relations between MD parameters and ICP and/or CPP in patients with TBI. Methods Cerebral MD, ICP and CPP were monitored in 90 patients with TBI. Data were extensively analyzed, using over 7,350 samples of complete (hourly MD data sets (glucose, lactate, pyruvate and glycerol to seek representations of ICP, CPP and MD that were best correlated. MD catheter positions were located on computed tomography scans as pericontusional or nonpericontusional. MD markers were analyzed for correlations to ICP and CPP using time series regression analysis, mixed effects models and nonlinear (artificial neural networks computer-based pattern recognition methods. Results Despite much data indicating highly perturbed metabolism, MD shows weak correlations to ICP and CPP. In contrast, the autocorrelation of MD is high for all markers, even at up to 30 future hours. Consequently, subject identity alone explains 52% to 75% of MD marker variance. This indicates that the dominant metabolic processes monitored with MD are long-term, spanning days or longer. In comparison, short-term (differenced or Δ changes of MD vs. CPP are significantly correlated in pericontusional locations, but with less than 1% explained variance. Moreover, CPP and ICP were significantly related to outcome based on Glasgow Outcome Scale scores, while no significant relations were found between outcome and MD. Conclusions The

  3. A MEMS-based passive hydrocephalus shunt for body position controlled intracranial pressure regulation.

    Science.gov (United States)

    Johansson, Staffan B; Eklund, Anders; Malm, Jan; Stemme, Göran; Roxhed, Niclas

    2014-08-01

    This paper reports a novel micro electro mechanical system (MEMS) valve with posture controlled flow characteristics for improved treatment of hydrocephalus, a disease that is characterized by elevated pressure in the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. In contrast to conventional differential pressure CSF valves, the CSF valve presented here features a third port which utilizes hydrostatic pressure from a pressure compensating catheter to adapt CSF drainage to optimized levels irrespective of body position. Prototypes have been fabricated using standard MEMS manufacturing processes and the experimental evaluation successfully showed that the flow rate was adjustable with a varying hydrostatic pressure on the third port. Measured data showed that flow rate was at near ideal values at laying body position and that the flow rate can be adjusted to optimal values at standing body position by selecting an appropriate length of the pressure compensating catheter. This is the first pressure balanced CSF valve intended for body position controlled CSF pressure regulation.

  4. Diffusion tensor imaging detects early brain microstructure changes before and after ventriculoperitoneal shunt in children with high intracranial pressure hydrocephalus

    Science.gov (United States)

    Zhao, Cailei; Li, Yongxin; Cao, Weiguo; Xiang, Kui; Zhang, Heye; Yang, Jian; Gan, Yungen

    2016-01-01

    Abstract To explore the use of diffusion tensor imaging (DTI) parameters in the quantitative assessment of early brain microstructure changes before and after ventriculoperitoneal shunt in children with high intracranial pressure hydrocephalus. Ten patients with communicating hydrocephalus (age: 2–36 months) and 14 age-/gender-matched controls (age: 2–36 months) were enrolled in this study. All patients underwent the ventriculoperitoneal shunt procedure. The imaging data were collected before and 3 months after the operation. Regions of interests (ROIs) included the white matter near the frontal horn of the lateral ventricles (FHLV), the occipital horn of the lateral ventricles (OHLV), occipital subcortical (OS) area, frontal subcortical (FS) area, and thalamus. Fractional anisotropies (FA) and apparent diffusion coefficients (ADC) of the ROIs before and after ventriculoperitoneal shunt were compared between the patients and the controls. Three months after surgery, the patients recovered from the surgery with ameliorated intracranial pressure and slight improvement of clinical intelligence scale and motor scale. Before ventriculoperitoneal shunt, the FA values (except the right FHLV) were significantly decreased and the ADC values were significantly increased in the patients with hydrocephalus, compared with the controls. After the ventriculoperitoneal shunt, the FA values in the FHLV and OHLV of the patients were similar to the controls, but the FA values in other ROIs were still significantly lower than controls. The ADC values in the FS and OS white matter areas of the patients were similar to the controls; however, the ADC values in other ROIs were still significantly higher in patients. The increase of FA and the reduction in ADC in the ROIs preceded the clinical function improvement in patients with high intracranial pressure hydrocephalus and reflected the early changes in brain tissue microstructure, such as the compression of the white matter areas in

  5. Diffusion tensor imaging detects early brain microstructure changes before and after ventriculoperitoneal shunt in children with high intracranial pressure hydrocephalus.

    Science.gov (United States)

    Zhao, Cailei; Li, Yongxin; Cao, Weiguo; Xiang, Kui; Zhang, Heye; Yang, Jian; Gan, Yungen

    2016-10-01

    To explore the use of diffusion tensor imaging (DTI) parameters in the quantitative assessment of early brain microstructure changes before and after ventriculoperitoneal shunt in children with high intracranial pressure hydrocephalus.Ten patients with communicating hydrocephalus (age: 2-36 months) and 14 age-/gender-matched controls (age: 2-36 months) were enrolled in this study. All patients underwent the ventriculoperitoneal shunt procedure. The imaging data were collected before and 3 months after the operation. Regions of interests (ROIs) included the white matter near the frontal horn of the lateral ventricles (FHLV), the occipital horn of the lateral ventricles (OHLV), occipital subcortical (OS) area, frontal subcortical (FS) area, and thalamus. Fractional anisotropies (FA) and apparent diffusion coefficients (ADC) of the ROIs before and after ventriculoperitoneal shunt were compared between the patients and the controls.Three months after surgery, the patients recovered from the surgery with ameliorated intracranial pressure and slight improvement of clinical intelligence scale and motor scale. Before ventriculoperitoneal shunt, the FA values (except the right FHLV) were significantly decreased and the ADC values were significantly increased in the patients with hydrocephalus, compared with the controls. After the ventriculoperitoneal shunt, the FA values in the FHLV and OHLV of the patients were similar to the controls, but the FA values in other ROIs were still significantly lower than controls. The ADC values in the FS and OS white matter areas of the patients were similar to the controls; however, the ADC values in other ROIs were still significantly higher in patients.The increase of FA and the reduction in ADC in the ROIs preceded the clinical function improvement in patients with high intracranial pressure hydrocephalus and reflected the early changes in brain tissue microstructure, such as the compression of the white matter areas in the ROIs.

  6. Cardiac output in idiopathic normal pressure hydrocephalus: association with arterial blood pressure and intracranial pressure wave amplitudes and outcome of shunt surgery

    Directory of Open Access Journals (Sweden)

    Eide Per K

    2011-02-01

    Full Text Available Abstract Background In patients with idiopathic normal pressure hydrocephalus (iNPH responding to shunt surgery, we have consistently found elevated intracranial pressure (ICP wave amplitudes during diagnostic ICP monitoring prior to surgery. It remains unknown why ICP wave amplitudes are increased in these patients. Since iNPH is accompanied by a high incidence of vascular co-morbidity, a possible explanation is that there is reduced vascular compliance accompanied by elevated arterial blood pressure (ABP wave amplitudes and even altered cardiac output (CO. To investigate this possibility, the present study was undertaken to continuously monitor CO to determine if it is correlated to ABP and ICP wave amplitudes and the outcome of shunting in iNPH patients. It was specifically addressed whether the increased ICP wave amplitudes seen in iNPH shunt responders were accompanied by elevated CO and/or ABP wave amplitude levels. Methods Prospective iNPH patients (29 were clinically graded using an NPH grading scale. Continuous overnight minimally-invasive monitoring of CO and ABP was done simultaneously with ICP monitoring; the CO, ABP, and ICP parameters were parsed into 6-second time windows. Patients were assessed for shunt surgery on clinical grade, Evan's index, and ICP wave amplitude. Follow-up clinical grading was performed 12 months after surgery. Results ICP wave amplitudes but not CO or ABP wave amplitude, showed good correlation with the response to shunt treatment. The patients with high ICP wave amplitude did not have accompanying high levels of CO or ABP wave amplitude. Correlation analysis between CO and ICP wave amplitudes in individual patients showed different profiles [significantly positive in 10 (35% and significantly negative in 16 (55% of 29 recordings]. This depended on whether there was also a correlation between ABP and ICP wave amplitudes and on the average level of ICP wave amplitude. Conclusions These results gave no

  7. Assessment of the usability of a digital learning technology prototype for monitoring intracranial pressure.

    Science.gov (United States)

    Carvalho, Lilian Regina de; Évora, Yolanda Dora Martinez; Zem-Mascarenhas, Silvia Helena

    2016-08-29

    to assess the usability of a digital learning technology prototype as a new method for minimally invasive monitoring of intracranial pressure. descriptive study using a quantitative approach on assessing the usability of a prototype based on Nielsen's ten heuristics. Four experts in the area of Human-Computer interaction participated in the study. the evaluation delivered eight violated heuristics and 31 usability problems in the 32 screens of the prototype. the suggestions of the evaluators were critical for developing an intuitive, user-friendly interface and will be included in the final version of the digital learning technology. avaliar a usabilidade de um protótipo educacional digital sobre um novo método para monitoração da pressão intracraniana de forma minimamente invasivo para enfermeiros e médicos. estudo descritivo com abordagem quantitativa sobre a avaliação de usabilidade de um protótipo com base nas dez Heurísticas de Nielsen. Participaram quatro especialistas da área de Interação Humano Computador. a avaliação resultou em oito heurísticas violadas e 31 problemas de usabilidade nas 32 telas do protótipo. as sugestões dos avaliadores foram cruciais para o desenvolvimento de uma interface amigável e intuitiva e serão consideradas na versão final da tecnologia educacional digital. evaluar la usabilidad de un prototipo educacional digital sobre un nuevo método para monitorización de la presión intracraneal, de manera mínimamente invasiva. estudio descriptivo con abordaje cuantitativo sobre la evaluación de usabilidad de un prototipo con base en las diez reglas Heurísticas de Nielsen. Participaron cuatro especialistas del área de Interacción Humana Computador. la evaluación resultó en ocho reglas heurísticas violadas y 31 problemas de usabilidad en las 32 pantallas del prototipo. las sugestiones de los evaluadores fueron cruciales para el desarrollo de una interfaz amigable e intuitiva y éstas serán consideradas en la

  8. Lumbar subcutaneous shunt: a novel technique for therapeutic decision making in normal pressure hydrocephalus (NPH) and benign intracranial hypertension (BIH).

    Science.gov (United States)

    Ushewokunze, S; Haja Mydin, H N; Prasad, R; Mendelow, A D

    2008-10-01

    Selecting patients who will benefit from a permanent CSF diversion procedure in benign intracranial hypertension (BIH) or communicating hydrocephalus due to normal pressure hydrocephalus (NPH) has inherent problems. The percutaneous introduction of a lumbar subcutaneous shunt (LSS) under local anaesthesia facilitates both a prolonged CSF drainage under aseptic conditions and also elicits an adequate clinical response. We describe the technique of a lumbar subcutaneous shunt and our experience with its use in patients with BIH and NPH. Postprocedure changes in the patients' clinical status were noted. Patients with a transient clinical improvement underwent a subsequent definitive CSF diversion; those with a sustained clinical improvement or no change in symptoms had no further procedure.

  9. Influence of hypothermia, barbiturate therapy, and intracranial pressure monitoring on morbidity and mortality after near-drowning.

    Science.gov (United States)

    Bohn, D J; Biggar, W D; Smith, C R; Conn, A W; Barker, G A

    1986-06-01

    We retrospectively evaluated the clinical and pathologic effects of hypothermia and high-dose barbiturate therapy on hypoxic/ischemic cerebral injury after near-drowning in children. Of 40 near-drowned patients admitted to the ICU, 13 died, seven had permanent cerebral damage, and 20 survived. Twenty-four patients (group 1) were treated with a regime of hyperventilation, hypothermia, and high-dose phenobarbitone while intracranial pressure (ICP) was continuously monitored. Of ten who died in this group, three were diagnosed as having cerebral death shortly after admission; autopsy revealed severe cerebral edema with herniation. The remaining seven nonsurvivors had severe cerebral hypoxia without raised ICP and had the features of severe adult respiratory distress syndrome and hypoxic/ischemic damage to other organs. Six of these seven patients developed septicemia which was invariably associated with a profound neutropenia. Sixteen patients (group 2) were treated with a similar protocol but without hypothermia. Three of these patients died but only one developed septicemia. Neutropenia after resuscitation from near-drowning seemed to indicate a poor prognosis; the mean polymorphonuclear leukocyte count in nonsurvivors (1.9 +/- 0.5 X 10(9) cell/L) was significantly (p less than .01) lower than that in survivors (6.4 +/- 1.1 X 10(9) cell/L). Hypothermia was associated with a decreased number of circulating PMNs but did not increase the number of neurologically intact survivors. Similarly, although barbiturates may control ICP, their use did not improve outcome. Because severe cerebral edema and herniation after near-drowning is usually associated with irreversible brain damage, measures to control brain swelling such as hypothermia and barbiturates will be of little benefit.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Association of Inter-arm Blood Pressure Difference with Asymptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients

    Science.gov (United States)

    Wang, Yan; Zhang, Jin; Qian, Yuesheng; Tang, Xiaofeng; Ling, Huawei; Chen, Kemin; Li, Yan; Gao, Pingjin; Zhu, Dingliang

    2016-01-01

    Inter-arm blood pressure (BP) difference has been associated with ischemic stroke. Local atherosclerosis of stroke differ among vulnerable individuals, whereas intracranial arterial stenosis (ICAS) is more frequently affected Asians, and extracranial arterial stenosis (ECAS) is more prevalent among whites. We hereby sought to explore the association of inter-arm BP difference with ICAS and ECAS in stroke-free hypertensive patients in Chinese population. All the 885 subjects were evaluated of ICAS and ECAS through computerized tomographic angiography. Both arm BP was measured simultaneously by Vascular Profiler-1000 device. In the continuous study, ICAS was significantly associated with age, male, average brachial SBP, diabetes, anti-hypertensive treatment and inter-arm DBP difference. ECAS was associated with age, inter-arm SBP and LDL. In the categorical study, subjects with the top quartile of inter-arm DBP difference (≥4 mmHg) showed significantly higher risk of ICAS (OR = 2.109; 95% CI, 1.24–3.587). And the participants with the top quartile of inter-arm SBP difference (≥6 mmHg) showed significantly higher risk of ECAS (OR = 2.288; 95% CI, 1.309–3.998). In conclusion, we reported a diverse association of inter-arm SBP/DBP difference with the ICAS/ECAS. Inter-arm DBP difference might be the early symbol of ICAS in Chinese population, which need further verification in long-term cohort study. PMID:27412818

  11. A Consensus-Based Interpretation of the Benchmark Evidence from South American Trials: Treatment of Intracranial Pressure Trial.

    Science.gov (United States)

    Chesnut, Randall M; Bleck, Thomas P; Citerio, Giuseppe; Classen, Jan; Cooper, D James; Coplin, William M; Diringer, Michael N; Grände, Per-Olof; Hemphill, J Claude; Hutchinson, Peter J; Le Roux, Peter; Mayer, Stephan A; Menon, David K; Myburgh, John A; Okonkwo, David O; Robertson, Claudia S; Sahuquillo, Juan; Stocchetti, Nino; Sung, Gene; Temkin, Nancy; Vespa, Paul M; Videtta, Walter; Yonas, Howard

    2015-11-15

    Widely-varying published and presented analyses of the Benchmark Evidence From South American Trials: Treatment of Intracranial Pressure (BEST TRIP) randomized controlled trial of intracranial pressure (ICP) monitoring have suggested denying trial generalizability, questioning the need for ICP monitoring in severe traumatic brain injury (sTBI), re-assessing current clinical approaches to monitored ICP, and initiating a general ICP-monitoring moratorium. In response to this dissonance, 23 clinically-active, international opinion leaders in acute-care sTBI management met to draft a consensus statement to interpret this study. A Delphi method-based approach employed iterative pre-meeting polling to codify the group's general opinions, followed by an in-person meeting wherein individual statements were refined. Statements required an agreement threshold of more than 70% by blinded voting for approval. Seven precisely-worded statements resulted, with agreement levels of 83% to 100%. These statements, which should be read in toto to properly reflect the group's consensus positions, conclude that the BEST TRIP trial: 1) studied protocols, not ICP-monitoring per se; 2) applies only to those protocols and specific study groups and should not be generalized to other treatment approaches or patient groups; 3) strongly calls for further research on ICP interpretation and use; 4) should be applied cautiously to regions with much different treatment milieu; 5) did not investigate the utility of treating monitored ICP in the specific patient group with established intracranial hypertension; 6) should not change the practice of those currently monitoring ICP; and 7) provided a protocol, used in non-monitored study patients, that should be considered when treating without ICP monitoring. Consideration of these statements can clarify study interpretation.

  12. A comparative study of Mannitol and Piracetam for the treatment of patients with high intracranial pressure after intracranial tumor surgery%甘露醇和吡拉西坦在颅内肿瘤术后高颅内压患者中应用效果对照研究

    Institute of Scientific and Technical Information of China (English)

    潘薇; 潘俏凤

    2012-01-01

    目的 探讨20%甘露醇和吡拉西坦注射液治疗颅内肿瘤术后高颅内压患者的临床疗效及安全性.方法 应用随机数字表法将2009年2月~2012年2月在我院神经外科住院治疗的126例颅内肿瘤术后高颅内压患者分为对照和观察组,对照组患者给予快速静脉滴注20%甘露醇进行治疗,而观察组患者则给予快速静脉滴注20%吡拉西坦注射液进行治疗,其他治疗措施相同,比较对照组和观察组患者临床疗效和不良反应发生率.结果 观察组患者的治疗总有效率(96.83%)明显高于对照组的(87.30%),且对照组和观察组患者在不良反应发生率方面比较差异无统计学意义(P > 0.05).结论 20%吡拉西坦注射液治疗颅内肿瘤术后高颅内压临床疗效确切,降颅压疗效好,安全可靠,能够代替20%甘露醇治疗颅内肿瘤术后高颅内压,不良反应少,值得进一步推广.%Objective To investigate the clinical efficacy and safety of patients with high intracranial pressure after intracranial tumor surgery by Mannitol and Piracetam. Methods The clinical data of 126 cases of patients with high intracranial pressure after intracranial tumor surgery who were treated in the department of neurosurgery in our hospital from February 2009 to February 2012 were collected, then patients were divided into the control group and observation group by using a random number table, patients in the control group were given 20% Mannitol by rapid intravenous drip, but patients in the observation group were given 20% piracetam Injection by rapid intravenous drip, but the other measures were the same, the clinical efficacy and adverse reaction of patients with high intracranial pressure after intracranial tumor surgery of two groups were evaluated. Results The total efficient rate in the observation group was higher than that in the control group (96.83% vs 87.30%, P 0.05). Conclusion 20% Piracetam can obtaine satisfactory curative effect for

  13. Vitamin A and Idiopathic Intracranial Hypertension

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-11-01

    Full Text Available Vitamin A levels were measured in the cerebrospinal fluid of a total of 78 patients having idiopathic intracranial hypertension (IIH;n=20, elevated pressure of other causes (E-ICP;n=19, and normal pressure (N-ICP;n=39, in a study at the University of Utah, Salt Lake City, UT.

  14. The impact and significance of anesthetics on intracranial pressure%麻醉药对颅内压的影响及意义

    Institute of Scientific and Technical Information of China (English)

    陆彬堂

    2013-01-01

    Reduce intracranial pressure to help patients with cerebral perfusion and surgical exposure in neurosurgical perioperative. Reasonable to choose anesthetics and anesthesia security, it is necessary to grasp the impact factors of intracranial pressure and anesthetics on neurosurgery perioperative intracranial pressure affect the mechanism.%  神经外科围术期,降低颅内压利于患者脑灌注和手术暴露。掌握颅内压的影响因素,了解麻醉药物对神经外科围术期颅内压影响机制,有利于合理选择麻醉药及提高麻醉安全性。

  15. High pressure rinsing parameters measurements

    Energy Technology Data Exchange (ETDEWEB)

    Cavaliere, E. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Fusetti, M. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Michelato, P. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Pagani, C. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy)]. E-mail: carlo.pagani@mi.infn.it; Pierini, P. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Paulon, R. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy); Sertore, D. [INFN Milano - LASA, Via F.lli Cervi 201, I-20090 Segrate (MI) (Italy)

    2006-07-15

    High pressure rinsing with ultra pure water jet is an essential step in the high field superconducting cavity production process. In this paper, we illustrate the experimental characterization of a HPR system, in terms of specific power and energy deposition on the cavity surfaces and on the damage threshold for niobium. These measurements are used to tentatively derive general rules for the optimization of the free process parameters (nozzle geometry, speeds and water pressure)

  16. Evaluation of the characteristics of various types of coils for the embolization of intracranial aneurysms with an optical pressure sensor system.

    Science.gov (United States)

    Matsubara, Noriaki; Miyachi, Shigeru; Nagano, Yoshitaka; Ohshima, Tomotaka; Hososhima, Osamu; Izumi, Takashi; Tsurumi, Arihito; Wakabayashi, Toshihiko; Sano, Akihito; Fujimoto, Hideo

    2011-03-01

    In coil embolization for an intracranial aneurysm, it is important to appropriately choose the coil most suitable for coping with various unforeseen situations. Additionally, because dense coil packing of the aneurysm sac is the most important factor to avoid a recurrence, properly selecting the coil is essential. In this article, the authors measured the coil insertion pressure of various types of coils with a newly developed sensor system, and coil characteristics were investigated. The sensor consists of a hemostatic valve connected to the proximal end of a microcatheter. The sensor principle is based on an optical system. Using this, an experimental silicone aneurysm embolization was performed automatically at constant speed. The pattern of the insertion pressure and the maximum insertion pressure (MIP) were analyzed for the various types of coils. The sensor continuously monitored the mechanical force during the insertions. The sensor adequately recorded the coil insertion pressure during embolization in each coil. MIP was generally ranked in order of the coil type. The soft type coils required relatively less insertion pressure than standard/helical and 3D type. As for the patterns of coil insertion pressure, each coil presented a saw-like pressure pattern, though we observed some slight differences. 3D type coils showed peak pressure at the moment of "painting". Coil loop diameters barely affected MIP. However, as to the patterns of pressure, larger size coils more often presented the peak. Coil characteristics were well evaluated. The results obtained here reflected some actual clinical experience. Furthermore, collecting the in vivo study is mandatory, which may provide clinically useful data.

  17. Temperature variability in the day-night cycle is associated with further intracranial pressure during therapeutic hypothermia.

    Science.gov (United States)

    Nogueira, Adriano Barreto; Annen, Eva; Boss, Oliver; Farokhzad, Faraneh; Sikorski, Christopher; Keller, Emanuela

    2017-08-03

    To assess whether circadian patterns of temperature correlate with further values of intracranial pressure (ICP) in severe brain injury treated with hypothermia. We retrospectively analyzed temperature values in subarachnoid hemorrhage patients treated with hypothermia by endovascular cooling. The circadian patterns of temperature were correlated with the mean ICP across the following day (ICP24). We analyzed data from 17 days of monitoring of three subarachnoid hemorrhage patients that underwent aneurysm coiling, sedation and hypothermia due to refractory intracranial hypertension and/or cerebral vasospasm. ICP24 ranged from 11.5 ± 3.1 to 24.2 ± 6.2 mmHg. The ratio between the coefficient of variation of temperature during the nocturnal period (18:00-6:00) and the preceding diurnal period (6:00-18:00) [temperature variability (TV)] ranged from 0.274 to 1.97. Regression analysis showed that TV correlated with ICP24 (Pearson correlation = -0.861, adjusted R square = 0.725, p TV) mmHg or, for 80% prediction interval, [Formula: see text] mmHg. The results indicate that the occurrence of ICP24 higher than 20 mmHg is unlikely after a day with TV ≥1.0. TV correlates with further ICP during hypothermia regardless the strict range that temperature is maintained. Further studies with larger series could clarify whether intracranial hypertension in severe brain injury can be predicted by analysis of oscillation patterns of autonomic parameters across a period of 24 h or its harmonics.

  18. [Idiopathic intracranial hypertension: a caesarean with epidural anaesthesia after bringing the cerebrospinal fluid pressure back to normal].

    Science.gov (United States)

    Pérez Rodríguez, M; de Carlos Errea, J; Dorronsoro Auzmendi, M; Batllori Gastón, M

    2013-12-01

    Idiopathic intracranial hypertension is diagnosed by exclusion. Because of its uncertain physiopathology and infrequent occurrence, its anaesthetic management is not well defined. The patient in this case is a pregnant woman with this disease with no lumbar-peritoneal shunt who was referred for non-urgent caesarean section, consisting of CSF drainage and pressure normalisation before the administration of epidural anaesthesia. We believe this technique can de effective to achieve adequate blockage and increased patient comfort, as well as improving postoperative recovery. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

  19. Reliability and Validity of the Therapy Intensity Level Scale : Analysis of Clinimetric Properties of a Novel Approach to Assess Management of Intracranial Pressure in Traumatic Brain Injury

    NARCIS (Netherlands)

    Zuercher, Patrick; Groen, Justus L.; Aries, Marcel J. H.; Steyerberg, Ewout W.; Maas, Andrew I. R.; Ercole, Ari; Menon, David K.

    2016-01-01

    We aimed to assess the reliability and validity of the Therapy Intensity Level scale (TIL) for intracranial pressure (ICP) management. We reviewed the medical records of 31 patients with traumatic brain injury (TBI) in two European intensive care units (ICUs). The ICP TIL was derived over a 4-day

  20. Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage. Laboratory investigation

    DEFF Research Database (Denmark)

    Ansar, Saema; Edvinsson, Lars

    2009-01-01

    OBJECT: Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the...

  1. Equal contribution of increased intracranial pressure and subarachnoid blood to cerebral blood flow reduction and receptor upregulation after subarachnoid hemorrhage. Laboratory investigation

    DEFF Research Database (Denmark)

    Ansar, Saema; Edvinsson, Lars

    2009-01-01

    OBJECT: Cerebral ischemia remains the key cause of disability and death in the late phase after subarachnoid hemorrhage (SAH), and its pathogenesis is still poorly understood. The purpose of this study was to examine whether the change in intracranial pressure or the extravasated blood causes the...

  2. Low-pressure balloon angioplasty with adjuvant pharmacological therapy in patients with acute ischemic stroke caused by intracranial arterial occlusions

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Raul G. [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, Endovascular Neurosurgery/Interventional Neuroradiology Section, Boston, MA (United States); Massachusetts General Hospital, Harvard Medical School, Department of Neurosurgery, Endovascular Neurosurgery/Interventional Neuroradiology Section, Boston, MA (United States); Massachusetts General Hospital, Harvard Medical School, Department of Neurology, Neurocritical Care and Vascular Neurology Section, Boston, MA (United States); Massachusetts General Hospital, Boston, MA (United States); Schwamm, Lee H.; Buonanno, Ferdinando S.; Koroshetz, Walter J. [Massachusetts General Hospital, Harvard Medical School, Department of Neurology, Neurocritical Care and Vascular Neurology Section, Boston, MA (United States); Yoo, Albert J.; Rabinov, James D.; Pryor, Johnny C.; Hirsch, Joshua A. [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, Endovascular Neurosurgery/Interventional Neuroradiology Section, Boston, MA (United States); Massachusetts General Hospital, Harvard Medical School, Department of Neurosurgery, Endovascular Neurosurgery/Interventional Neuroradiology Section, Boston, MA (United States)

    2008-04-15

    The use of coronary balloons in the cerebral vasculature is limited due to their poor trackability and increased risk of vessel injury. We report our experience using more compliant elastomer balloons for thrombus resistant to intraarterial (IA) pharmacological and mechanical thrombolysis in acute stroke. We retrospectively analyzed 12 consecutive patients with an occluded intracranial artery treated with angioplasty using a low-pressure elastomer balloon. Angiograms were graded according to the Thrombolysis in Cerebral Infarction (TICI) and Qureshi grading systems. Outcomes were categorized as independent (modified Rankin scale, mRS, score {<=}2), dependent (mRS score 3-5), or dead (mRS score 6). Included in the study were 12 patients (mean age 66{+-}17 years, range 31-88 years; mean baseline National Institutes of Health stroke scale score 17{+-}3, range 12-23). The occlusion sites were: internal carotid artery (ICA) terminus (five patients, including two concomitant cervical ICA occlusions), M1 segment (two patients), and basilar artery (two patients). Pharmacological treatment included intravenous (IV) t-PA only (two patients), IA urokinase only (nine patients), both IV t-PA and IA urokinase (one patient), and IV and/or IA eptifibatide (eight patients). Mean time to treatment was 5.9{+-}3.9 h (anterior circulation) and 11.0{+-}7.2 h (posterior circulation). Overall recanalization rate (TICI grade 2/3) was 91.6%. Procedure-related morbidity occurred in one patient (distal posterior inferior cerebellar artery embolus). There were no symptomatic hemorrhages. Outcomes at 90 days were independent (five patients), dependent (three patients) and dead (four patients, all due to progression of stroke with withdrawal of care). Angioplasty of acutely occluded intracranial arteries with low-pressure elastomer balloons results in high recanalization rates with an acceptable degree of safety. Prior use of thrombolytics may increase the chances of recanalization, and

  3. Ventriculoperitoneal shunts for treating increased intracranial pressure in cryptococcal meningitis with or without ventriculomegaly

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    Marcelo Corti

    2014-07-01

    Full Text Available Introduction Cryptococcosis is an opportunistic mycosis, especially in patients that are human immunodeficiency virus (HIV-positive, and frequently involves the central nervous system. Methods We assessed the potential of ventriculoperitoneal shunting (VPS in preventing mortality due to uncontrollable intracranial hypertension (ICH in 15 patients with acquired immunodeficiency syndrome (AIDS-related cryptococcal meningitis. Results After 2 weeks of antifungal therapy consisting of amphotericin B deoxycholate with or without fluconazole, patients with persistent ICH underwent VPS, despite having persistent Cryptococcus neoformans infection. In 12 patients, the uncontrollable ICH was resolved by VPS. Conclusions Patients with cryptococcal meningoencephalitis who have ICH must be considered for VPS even with positive cerebrospinal fluid cultures.

  4. T2-weighted magnetic resonance imaging measurements of optic nerve sheath diameter in dogs with and without presumed intracranial hypertension.

    Science.gov (United States)

    Scrivani, Peter V; Fletcher, Daniel J; Cooley, Stacy D; Rosenblatt, Alana J; Erb, Hollis N

    2013-01-01

    Intracranial hypertension is a cause of cerebral ischemia and neurologic deficits in dogs. Goals of this retrospective study were to test interobserver agreement for MRI measurements of optic nerve sheath diameter and associations between optic nerve sheath diameter, signalment data, and presumed intracranial hypertension status in a cohort of dogs. A veterinary radiologist interpreted scans of 100 dogs and dogs were assigned to groups based on presence or absence of at least two MRI characteristics of presumed intracranial hypertension. Two observers who were unaware of group status independently measured optic nerve diameter from transverse T2-weighted sequences. Mean optic nerve sheath diameter for all dogs was 3 mm (1-4 mm). The mean difference between observers was 0.3 mm (limits of agreement, -0.4 and 1.0 mm). There was no correlation between optic nerve sheath diameter and age for either observer (r = -0.06 to 0.00) but a moderate positive correlation was observed between optic nerve sheath diameter and body weight for both observers (r = 0.70-0.76). The 22 dogs with presumed intracranial hypertension weighed less than the 78 dogs without (P = 0.02) and were more often female (P = 0.04). Dogs with presumed intracranial hypertension had a larger ratio of optic nerve sheath diameter to body weight for each observer-side pair (P = 0.01-0.04) than dogs without. Findings indicated that the ratio of MRI optic nerve sheath diameter relative to body weight may be a repeatable predictor of intracranial hypertension in dogs.

  5. Influência da fisioterapia respiratória na pressão intracraniana em pacientes com traumatismo craniencefálico grave Influence of the respiratory physioterapy on intracranial pressure in severe head trauma patients

    Directory of Open Access Journals (Sweden)

    Rosana A. Thiesen

    2005-03-01

    Full Text Available OBJETIVO: Estudar a influência das manobras de fisioterapia respiratória na pressão intracraniana (PIC dos pacientes com trauma craniencefálico grave. MÉTODO: Trinta e cinco pacientes com trauma craniencefálico grave foram incluídos no estudo, sendo divididos em três grupos: com PIC OBJECTIVE: To evaluate influence of the respiratory physiotherapy on intracranial pressure (ICP in patients with severe head trauma. METHOD: Thirty five patients with severe head trauma were included in the study.The patients were divided into three groups: ICP 0-10, 11-20 and 21-30 mmHg. The following variables were measured: ICP and mean arterial pressure. Cerebral perfusion pressure was calculated as the difference between mean arterial and intracranial pressure. RESULTS: Endotracheal aspiration increased ICP in all patients. The mean arterial pressure didn't change and cerebral perfusion pressure decreased, but remaning normal value. CONCLUSION: Respiratory physiotherapy maneuvers can be safely applied in patients with severe head trauma with ICP below 30 mmHg. More attention should be taken during endotracheal aspiration .

  6. Intracranial pressure monitoring and inpatient mortality in severe traumatic brain injury: A propensity score-matched analysis.

    Science.gov (United States)

    Dawes, Aaron J; Sacks, Greg D; Cryer, H Gill; Gruen, J Peter; Preston, Christy; Gorospe, Deidre; Cohen, Marilyn; McArthur, David L; Russell, Marcia M; Maggard-Gibbons, Melinda; Ko, Clifford Y

    2015-03-01

    Although intracranial pressure (ICP) monitoring in severe traumatic brain injury (TBI) is recommended by the Brain Trauma Foundation, the benefits remain controversial. We sought to determine the impact of ICP monitor placement on inpatient mortality within a regional trauma system after correcting for selection bias through propensity score matching. Data were collected on all severe TBI cases presenting to 14 trauma centers during the 2-year study period (2009-2010). Inclusion criteria were as follows: blunt injury, Glasgow Coma Scale (GCS) score of 8 or lower in the emergency department, and abnormal intracranial findings on head computed tomography (CT). Two separate multivariate logistic regression models were used to predict ICP monitor placement and inpatient mortality after controlling for demographics, severity of injury, comorbidities, and TBI-specific variables (GCS score, pupil reactivity, international normalized ratio, and nine specific head CT findings). To account for selection bias, we developed a propensity score-matched model to estimate the "true" effect of ICP monitoring on in-hospital mortality. A total of 844 patients met inclusion criteria; 22 died on arrival to the emergency department. Inpatient mortality was 38.8%; 46.0% of the patients underwent ICP monitor placement. Unadjusted mortality rates were significantly lower in the ICP monitoring group (30.7% vs. 45.7%, p propensity score matching, ICP monitor placement was associated with an 8.3 percentage point reduction in the risk-adjusted mortality rate. ICP monitor placement occurred in only 46% of eligible patients but was associated with significantly decreased mortality after adjusting for baseline risk profile and the propensity to undergo monitoring. As the individual impact of ICP monitoring may vary, future efforts must determine who stands to benefit from invasive monitoring techniques. Therapeutic/care management study, level III.

  7. Perioperative monitoring of pulsatile and static intracranial pressure in patients with Chiari malformation type 1 undergoing foramen magnum decompression.

    Science.gov (United States)

    Frič, Radek; Eide, Per Kristian

    2016-02-01

    Patients with Chiari malformation type 1 (CMI) often present with elevated pulsatile and static intracranial pressure (ICP). The preferred treatment of CMI, foramen magnum decompression (FMD), is assumed to normalise ICP and craniospinal pressure dissociation. In order to further explore the mechanisms behind FMD, the present study investigated whether or not pulsatile and static ICP normalises immediately after FMD. The study included CMI patients undergoing FMD with perioperative ICP monitoring as a part of clinical management. The pulsatile and static ICP scores were retrieved from the department's ICP database, and the clinical and radiological data from the patient records. Eleven patients were included in the study. During the first 3 days following FMD, mixed model analysis revealed no significant time-dependent differences of preoperatively elevated either pulsatile (mean wave amplitude, MWA; p = 0.85) and/or static (mean ICP, p = 0.90) ICP. Percentage of mean ICP >15 mmHg increased during days 2 and 3 after FMD. Two patients from the present series had to receive ventriculoperitoneal shunt after FMD in the early postoperative period. The present observations suggest that anatomical restoration of cerebrospinal fluid pathways by FMD does not lead to immediate normalisation of preoperatively altered pulsatile and static ICP in patients with CMI. This finding may explain persistent symptoms during the early period after FMD.

  8. Continuous Monitoring of Cerebrovascular Reactivity Using Pulse Waveform of Intracranial Pressure

    NARCIS (Netherlands)

    Aries, M.J.H.; Czosnyka, Marek; Budohoski, Karol P.; Kolias, Angelos G.; Radolovich, Danila K.; Lavinio, Andrea; Pickard, John D.; Smielewski, Peter

    2012-01-01

    Guidelines for the management of traumatic brain injury (TBI) call for the development of accurate methods for assessment of the relationship between cerebral perfusion pressure (CPP) and cerebral autoregulation and to determine the influence of quantitative indices of pressure autoregulation on out

  9. Increased intracranial pressure in a case of spinal cervical glioblastoma multiforme: analysis of these two rare conditions

    Directory of Open Access Journals (Sweden)

    C.M. de Castro-Costa

    1994-03-01

    Full Text Available The authors describe a rare case of increased intracranial hypertension consequent to a spinal cervical glioblastoma multiforme in a young patient. They analyse the physiopathology of intracranial hypertension in spinal tumors and the rarity of such kind of tumor in this location, and its clinico-pathological aspects.

  10. Measurement of flow diverter hydraulic resistance to model flow modification in and around intracranial aneurysms.

    Science.gov (United States)

    Ugron, Adám; Szikora, István; Paál, György

    2014-06-01

    Flow diverters (FDs) have been successfully applied in the recent decade to the treatment of intracranial aneurysms by impairing the communication between the flows in the parent artery and the aneurysm and, thus, the blood within the aneurysm sac. It would be desirable to have a simple and accurate computational method to follow the changes in the peri- and intraaneurysmal flow caused by the presence of FDs. The detailed flow simulation around the intricate wire structure of the FDs has three disadvantages: need for high amount of computational resources and highly skilled professionals to prepare the computational grid, and also the lack of validation that makes the invested effort questionable. In this paper, we propose a porous layer method to model the hydraulic resistance (HR) of one or several layers of the FDs. The basis of this proposal is twofold: first, from an application point of view, the only interesting parameter regarding the function of the FD is its HR; second, we have developed a method to measure the HR with a simple apparatus. We present the results of these measurements and demonstrate their utility in numerical simulations of patient-specific aneurysm simulations.

  11. Efeitos da fisioterapia respiratória na pressão intracraniana e pressão de perfusão cerebral no traumatismo cranioencefálico grave Effects of respiratory physiotherapy on intracranial pressure and cerebral perfusion pressure in severe traumatic brain injury patients

    Directory of Open Access Journals (Sweden)

    Cassia Toledo

    2008-12-01

    patients with severe traumatic brain injury, mechanically ventilated and with a continued measurement of intracranial pressure. The effects of manual vibrocompression maneuvers and intratracheal aspiration with or without saline infusion on the measurements of intracranial and cerebral perfusion pressures, between the first and third day after cerebral injury were evaluated. RESULTS: Data were collected from 11 patients, 41 years of age (median and APACHE II of 19.5 ± 5. The manual vibrocompression maneuver did not cause an increase of intracranial pressure on any of the days assessed. Intracranial pressure significantly increased after intratracheal aspiration maneuvers in relation to the basal measurement (day1, 9.5 ± 0.9 mm Hg vs 18.0 ± 3.2 mm Hg; day 2, 10.6 ± 1.7 mm Hg vs 21.4 ± 3.8 mm Hg; day 3, 14.4 ± 1.0 vs 24.9 ± 2.7 mm Hg; p<0.05 for all. However, these elevations were transient (about 27 seconds and accompanied by compensatory increases of the cerebral perfusion pressure. CONCLUSION: The manual vibrocompression maneuver did not increase intracranial pressure or cerebral perfusion pressure in patients with severe brain injury. Intratracheal aspiration induced a significant and transient increase of the intracranial and cerebral perfusion pressures.

  12. 闪光视觉诱发电位对颅内压变化的评估作用%Evaluative effects of flash visual evoked potential on the changes of intracranial pressure

    Institute of Scientific and Technical Information of China (English)

    周冀英; 贾建平; 王磊; 张拥波; 彭国光

    2005-01-01

    背景:闪光视觉诱发电位(flash visual evoked potential,VEP)可以反映从视网膜到枕皮质视通路的完整性,应用其特征可以准确评价视传导通路受损状况.目的:研究fVEP无创监测颅内压的可行性及其效应.设计:以患者为研究对象,重复测量设计.对象:2002-03/2003-10重庆医科大学附属第一医院及首都医科大学宣武医院脑损伤患者,共197例,男138例,女59例,平均年龄(38±9)岁.病种包括:脑硬膜外血肿20例、脑硬膜下血肿26例、脑挫裂伤4例、脑硬膜下血肿伴脑挫裂伤92例、脑挫裂伤伴脑内血肿55例.方法:采用fVEP与脑硬膜外测压法检测197例脑损伤患者颅内压水平,有创检测数据均在fVEP完成后立即采集,同时记录患者血压及心率变化.主要观察指标:fVEP结果,颅内压水平.结果:197例脑损伤患者平均颅内压水平(2.75±0.64)kPa(1.54~4.02 kPa);有明确视通路损伤患者无创与有创检测值离散度较大;2.79%的患者fVEP未诱发出典型波形;散点图提示fVEP与脑硬膜外测压法一致性较好;线性回归分析显示心率对颅内压水平的波动最敏感(β值为-0.369),其次是收缩压(β值为0.316),舒张压较不敏感(β值为0.147).心率与颅内压水平呈负相关,能较敏感地反应颅内压的波动,其次为收缩压,舒张压较不易受颅内压变化的影响.结论:fVEP无创颅内压检测值与有创检测值一致性良好,可以无创定量评估颅内压变化情况.%BACKGROUND: Flash visual evoked potential(fVEP) can reflect the integrity of visual pathway from retina to pulvinar cortex. The utilization of its characters can accurately evaluate the injury situation of visual conduction pathway.OBJECTIVE: To investigate the feasibility and effects of fVEP on non-traumatic monitoring of intracranial pressure.DESIGN: A repeated measurement design based on patients.PARTICIPANTS: Totally 197 patients with brain injury including 138males and 59 females with an

  13. Recurrent Attacks of Raised Intracranial Pressure in Case of Tuberculous Arachnoiditis

    Directory of Open Access Journals (Sweden)

    N. O. Ameli

    1960-01-01

    Full Text Available A ase of recurre'nt raised interacranial pressure is described. At operation posterio-rcfossa arachnoiditis was found. Histological examination suggested a Tuberculous etiology. Four months after the operation she died from an apparently acute tuberculoua meningiti

  14. Intraparenchymal intracranial pressure monitoring in patients with acute liver failure Monitoreo intraparenquimatoso de presión intracraneana en pacientes con falla hepática aguda

    OpenAIRE

    Rabadán, Alejandra T.; Natalia Spaho; Diego Hernández; Adrián Gadano; Eduardo de Santibañes

    2008-01-01

    BACKGROUND: Elevated intracranial pressure (ICP) is a common cause of death in acute liver failure (ALF) and is determinant for decision-making regarding the timing of liver transplantation. The recommended type ICP monitoring device is controversial in ALF patients. Epidural devices had less risk of hemorrhagic complications, but they are less reliable than intraparenchymal ones. METHOD: Twenty-three patients with ALF were treated, and 19 of them received a liver transplant. Seventeen patien...

  15. The best marker for guiding the clinical management of patients with raised intracranial pressure-the RAP index or the mean pulse amplitude?

    Science.gov (United States)

    Hall, Allan; O'Kane, Roddy

    2016-10-01

    Raised intracranial pressure is a common problem in a variety of neurosurgical conditions including traumatic brain injury, hydrocephalus and intracranial haemorrhage. The clinical management of these patients is guided by a variety of haemodynamic, biochemical and clinical factors. However to date there is no single parameter that is used to guide clinical management of patients with raised intracranial pressure (ICP). However, the role of ICP indices, specifically the mean pulse amplitude (AMP) and RAP index [correlation coefficient (R) between AMP amplitude (A) and mean ICP pressure (P); index of compensatory reserve], as an indicator of true ICP has been investigated. Whilst the RAP index has been used both as a descriptor of neurological deterioration in TBI patients and as a way of characterising the compensatory reserve in hydrocephalus, more recent studies have highlighted the limitation of the RAP index due to the influence that baseline effect errors have on the mean ICP, which is used in the calculation of the RAP index. These studies have suggested that the ICP mean pulse amplitude may be a more accurate marker of true intracranial pressure due to the fact that it is uninfluenced by the mean ICP and, therefore, the AMP may be a more reliable marker than the RAP index for guiding the clinical management of patients with raised ICP. Although further investigation needs to be undertaken in order to fully assess the role of ICP indices in guiding the clinical management of patients with raised ICP, the studies undertaken to date provide an insight into the potential role of ICP indices to treat raised ICP proactively rather than reactively and therefore help prevent or minimise secondary brain injury.

  16. Invasive and Ultrasound Based Monitoring of the Intracranial Pressure in an Experimental Model of Epidural Hematoma Progressing towards Brain Tamponade on Rabbits

    Directory of Open Access Journals (Sweden)

    Konstantinos Kasapas

    2014-01-01

    Full Text Available Introduction. An experimental epidural hematoma model was used to study the relation of ultrasound indices, namely, transcranial color-coded-Doppler (TCCD derived pulsatility index (PI, optic nerve sheath diameter (ONSD, and pupil constriction velocity (V which was derived from a consensual sonographic pupillary light reflex (PLR test with invasive intracranial pressure (ICP measurements. Material and Methods. Twenty rabbits participated in the study. An intraparenchymal ICP catheter and a 5F Swan-Ganz catheter (SG for the hematoma reproduction were used. We successively introduced 0.1 mL increments of autologous blood into the SG until the Cushing reaction occurred. Synchronous ICP and ultrasound measurements were performed accordingly. Results. A constant increase of PI and ONSD and a decrease of V values were observed with increased ICP values. The relationship between the ultrasound variables and ICP was exponential; thus curved prediction equations of ICP were used. PI, ONSD, and V were significantly correlated with ICP (r2=0.84±0.076, r2=0.62±0.119, and r2=0.78±0.09, resp. (all P<0.001. Conclusion. Although statistically significant prediction models of ICP were derived from ultrasound indices, the exponential relationship between the parameters underpins that results should be interpreted with caution and in the current experimental context.

  17. Effects of intracranial pressure on the pial microcirculation in rats studied by a fiber-optic laser-Doppler anemometer microscope.

    Science.gov (United States)

    Seki, J; Sasaki, Y; Oyama, T; Yamamoto, J

    1999-01-01

    The fiber-optic laser-Doppler anemometer microscope (FLDAM) developed in our laboratory was applied to measure red cell velocity in individual pial microvessels in rats to determine the effect of intracranial pressure (ICP) on the pial microcirculation. The red cell velocity and the vessel diameter of pial microvessels were measured through a closed cranial window at controlled values of ICP between 0 and 50 mmHg. As ICP increased from 0 to 50 mmHg, the average relative diameter of venules with respect to the diameter at an ICP of 5 mmHg decreased from 1.18 +/- 0.12 (mean +/- SD) to 0.74 +/- 0.08 and the average relative velocity increased from 0.80 +/- 0.20 to 1.83 +/- 0.42 monotonically. The changes in diameter and velocity of arterioles with ICP were small, and they were not significantly different from those values at an ICP of 5 mmHg except for the diameter at an ICP of 20 mmHg. The mean volume flow rates calculated assuming a circular vessel cross-section did not show any statistically significant change with ICP between 0 and 50 mmHg in both arterioles and venules, which supports the concept of autoregulation.

  18. PIV Measurement of Wall Shear Stress and Flow Structures within an Intracranial Aneurysm Model

    Science.gov (United States)

    Chow, Ricky; Sparrow, Eph; Campbell, Gary; Divani, Afshin; Sheng, Jian

    2012-11-01

    The formation and rupture of an intracranial aneurysm (IA) is a debilitating and often lethal event. Geometric features of the aneurysm bulb and upstream artery, such as bulb size, bulb shape, and curvature of the artery, are two groups of factors that define the flow and stresses within an IA. Abnormal flow stresses are related to rupture. This presentation discusses the development of a quasi-3D PIV technique and its application in various glass models at Re = 275 and 550 to experimentally assess at a preliminary level the impact of geometry and flow rate. Some conclusions are to be drawn linking geometry of the flow domain to rupture risk. The extracted results also serve as the baseline case and as a precursor to a companion presentation by the authors discussing the impact of flow diverters, a new class of medical devices. The PIV experiments were performed in a fully index-matched flow facility, allowing for unobstructed observations over complex geometry. A reconstruction and analysis method was devised to obtain 3D mean wall stress distributions and flow fields. The quasi 3D measurements were reconstructed from orthogonal planes encompassing the entire glass model, spaced 0.4mm apart. Wall shear stresses were evaluated from the near-wall flow viscous stresses.

  19. “Spontaneous” CSF Fistula due to Transtegmental Brain Herniation in Combination with Signs of Increased Intracranial Pressure and Petrous Bone Hyperpneumatization: An Illustrative Case Report

    Science.gov (United States)

    Rivera, Diones; Fermin-Delgado, Rafael; Stoeter, Peter

    2014-01-01

    Background and Importance Transtegmental brain herniation into the petrous bone is a rare cause of rhinoliquorrhea. Our case presents a combination of several typical clinical and imaging findings illustrating the ongoing etiologic discussion of such cerebrospinal fluid (CSF) fistulas. Clinical Presentation A 53-year-old man presented with nasal discharge after a strong effort to suppress coughing. Imaging revealed a transtegmental herniation of parts of the inferior temporal gyrus into the petrous bone and in addition a combination of signs of chronically increased intracranial pressure and a hyperpneumatization of the petrous bone. The fistula was closed by a middle cranial fossa approach. Conclusion The case illustrates the two main predisposing factors for development of petrous bone CSF fistulas: increased intracranial pressure and thinning of the tegmental roof due to extensive development of air cells. Because the CSF leakage repair does not change the underlying cause, patients have to be informed about the possibility of developing increased intracranial pressure and recurrences of brain herniations at other sites. PMID:25485224

  20. Non-Invasive Ultrasonic Diagnosing and Monitoring of Intracranial Pressure/Volume

    Science.gov (United States)

    2001-10-01

    related to cardiovascular parameters. ICP VI, Eds. Miller JD, Teasdale GM, Rowan JO, Galbraith SL, Mendelow AD. Springer-Verlag Berlin Heidelberg, 290...Galbraith AD Mendelow (Springer Berlin Heidelberg) 305-309 43. Hayashi M, Handa Y, Kobayashi H, Kawano H, Ishii H, Hirose S (1991). Plateau-wave...Galbraith SL, Mendelow AD Springer-Verlag Berlin Heidelberg. 151-155 72. Maeda M, Tanaka K, Nishimur S, Matsuura S (1986). Pressure wave-like changes in

  1. Headache attributed to intracranial pressure alterations: applicability of the International Classification of Headache Disorders ICHD-3 beta version versus ICHD-2.

    Science.gov (United States)

    Curone, M; Peccarisi, C; Bussone, G

    2015-05-01

    The association between headache and changes in intracranial pressure is strong in clinical practice. Syndromes associated with abnormalities of cerebrospinal fluid (CSF) pressure include spontaneous intracranial hypotension (SIH) and idiopathic intracranial hypertension (IIH). In 2013, the Headache Classification Committee of the International Headache Society (IHS) published the third International Classification of Headache Disorders (ICHD-3 beta version). The aim of this study was to investigate applicability of the new ICHD-3 versus ICHD-2 criteria in a clinical sample of patients with intracranial pressure (ICP) alterations. Patients admitted at our Headache Center for headache evaluation in whom a diagnosis of ICP alterations was performed were reviewed. 71 consecutive patients were studied. 40 patients (Group A) were diagnosed as IIH, 22 (Group B) as SIH, 7 (Group C) and 2 (Group D), respectively, as symptomatic intracranial hypertension and symptomatic intracranial hypotension. Main headache features were: in Group A, daily or nearly-daily headache (100 %) with diffuse/non-pulsating pain (73 %), aggravated by coughing/straining (54 %) and migrainous-associated symptoms (43 %). In Group B, an orthostatic headache (100 %) with nausea (29 %), vomiting (24 %), hearing disturbance (33 %), neck pain (48 %), hypacusia (24 %), photophobia (22 %) was reported. In Group C, a diffuse non-pulsating headache was present in 95 % with vomiting (25 %), sixth nerve palsy (14 %) and tinnitus (29 %). In Group D, an orthostatic headache with neck stiffness was reported by 100 %. Regarding applicability of ICHD-2 criteria in Group A, 73 % of the patients fitted criterion A; 100 %, criterion B; 100 %, criterion C; and 75 %, criterion D; while applying ICHD-3 beta version criteria, 100 % fitted criterion A; 97.5 %, criterion B; 100 %, criterion C; and 100 %, criterion D. In Group B, application of ICHD-2 showed 91 % patients fitting criterion A; 100 %, criterion B; 100

  2. Pressures Detector Calibration and Measurement

    CERN Document Server

    AUTHOR|(CDS)2156315

    2016-01-01

    This is report of my first and second projects (of 3) in NA61. I did data taking and analysis in order to do calibration of pressure detectors and verified it. I analyzed the data by ROOT software using the C ++ programming language. The first part of my project was determination of calibration factor of pressure sensors. Based on that result, I examined the relation between pressure drop, gas flow rate of in paper filter and its diameter.

  3. Reliability and Validity of the Therapy Intensity Level Scale: Analysis of Clinimetric Properties of a Novel Approach to Assess Management of Intracranial Pressure in Traumatic Brain Injury.

    Science.gov (United States)

    Zuercher, Patrick; Groen, Justus L; Aries, Marcel J H; Steyerberg, Ewout W; Maas, Andrew I R; Ercole, Ari; Menon, David K

    2016-10-01

    We aimed to assess the reliability and validity of the Therapy Intensity Level scale (TIL) for intracranial pressure (ICP) management. We reviewed the medical records of 31 patients with traumatic brain injury (TBI) in two European intensive care units (ICUs). The ICP TIL was derived over a 4-day period for 4-h (TIL4) and 24-h epochs (TIL24). TIL scores were compared with historical schemes for TIL measurement, with each other, and with clinical variables. TIL24 scores in ICU patients with TBI were compared with two control groups: patients with extracranial trauma necessitating intensive care (Trauma_ICU; n = 20) and patients with TBI not needing ICU care (TBI_WARD; n = 19), to further determine the discriminative validity of the TIL for ICP-related ICU interventions. Interrater and intraobserver agreement were excellent for TIL4 and TIL24 (Cohen κ: 0.98-0.99; intraclass correlation coefficient: 0.99-1; p intensity level of ICP management in patients with TBI.

  4. Spatial resolution in plantar pressure measurement revisited.

    Science.gov (United States)

    Pataky, Todd C

    2012-08-09

    Plantar pressures are typically measured using sensors of finite area, so the accuracy with which one can measure true maximum pressure is dependent on sensor size. Measurement accuracy has been modeled previously for one patient's metatarsals (Lord, 1997), but has not been modeled either for general subjects or for other parts of the foot. The purposes of this study were (i) to determine whether Lord's (1997) model is also valid for heel and hallux pressures, and (ii) to examine how sensor size relates to measurement accuracy in the context of four factors common to many measurement settings: pressure pulse size, foot positioning, pressure change quantification, and gross pressure redistribution. Lord's (1997) model was first generalized and was then validated using 10 healthy walking subjects, with relatively low RMSE values on the order of 20 kPa. Next, postural data were used to show that gross pressure redistributions can be accurately quantified (ppressure measurement tasks.

  5. Application of T2* measurement on gradient echo T2*-weighted imaging in differential diagnosis of intracranial hemorrhage and calcification

    Institute of Scientific and Technical Information of China (English)

    LIU Lan-xiang; YI Hui-ling; HAN Hong-bin; QI Xi-ming

    2012-01-01

    Background Differential diagnosis of intracranial hemorrhage and calcification is a common problem encountered in clinical imaging diagnosis.The purpose of this study was to investigate the feasibility of T2* measurement on gradient echo (GRE) T2*-weighted imaging (T2*WI) in differential diagnosis of intracranial hemorrhage and calcification.Methods Thirty-eight hemorrhagic foci in 18 patients and 11 calcification foci in seven patients were included in this study.The diagnosis of hemorrhage and calcification was confirmed in all cases with enhanced T2* weighted angiography (ESWAN) magnetic resonance imaging (MRI) and CT respectively.The significance for the difference of T2* value between the central and peripheral areas of hemorrhage and calcification lesions was tested with univariate analysis of variance.Results The detection rate of GRE T2*WI on intracranial hemorrhage was 1.9-fold higher than that of CT,especially for the hemorrhage in the brainstem and cerebellum.However,GRE T2*WI was far less sensitive to calcification than CT.There was a significant difference in the T2* value between the central area of hemorrhage and calcification (P <0.001),though no difference in the T2* value was obtained between the peripheral area of hemorrhage and calcification (P>0.05).Conclusions Quantitative measurement of T2* value on GRE T2*WI with a single MRI examination provides a fast,convenient,and effective means in differential diagnosis between intracranial hemorrhage and calcification,which may thus reduce the medical cost and save precious time for clinical management.

  6. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  7. Hipertensão intracraniana em vítimas fatais de acidente de trânsito Increased intracranial pressure in victims of fatal road traffic accident

    Directory of Open Access Journals (Sweden)

    JOSÉ EYMARD HOMEM PITTELLA

    1999-09-01

    Full Text Available Foi realizada análise morfológica, macro e microscópica, das lesões encefálicas de 120 vítimas fatais de acidente de trânsito. A hérnia para-hipocampal, a hemorragia de Duret e o infarto médio-basal occipital, indicadores fidedignos de que o paciente apresentou hipertensão intracraniana (HIC, ocorreram em 43 pacientes (35,8%. A HIC no trauma cranioencefálico é causada pela tumefação cerebral congestiva e pelos hematomas intracranianos. Na presente casuística foram observados 3 hematomas extradurais (7,0%, 9 hematomas subdurais agudos (20,9%, 6 hematomas intracerebrais (14%, 6 explosões lobares (14% e 9 tumefações cerebrais congestivas (20,9%.A morphological study, macro and microscopical, was made of brain lesions in 120 victims of fatal road traffic accidents. Parahipoccampal hernia, Duret haemorrhage and infarction in the medio-basal occipital lobe, clear evidence of raised intracranial pressure, occurred in 43 (35.8% patients. The increased intracranial pressure from the head injury is caused by brain swelling and by intracranial haematomas. In this series 3 cases of extradural haematomas (7.0%, 9 of subdural haematomas (20.9%, 6 of intracerebral haematomas (14%, 6 of burst lobe (14% and 9 of brain swelling (20.9% were observed.

  8. Effect of anesthesia induction with muscle relaxant and opioid on intracranial pressure and cerebral perfusion pressure in patients with intracranial tumors%肌肉松弛剂和阿片类药物麻醉诱导对颅内肿瘤患者颅内压及脑灌注压的影响

    Institute of Scientific and Technical Information of China (English)

    胡玉红

    2012-01-01

    目的:探讨肌肉松弛剂和阿片类药物对颅内肿瘤患者颅内压和脑灌注压的影响.方法:选取2008-03~2011-03颅内肿瘤患者80例,随机分为2组.对照组使用常规麻醉,试验组使用肌肉松弛剂琥珀酰胆碱和阿片类药物芬太尼作诱导,再予常规麻醉,观察2组颅内压和脑灌注压的影响.结果:试验组术前、术中20 min、40 min、术毕后的颅内压、脑灌注压及术后苏醒时间与对照组相比均有显著差异(P<0.05).结论:在常规麻醉前使用肌肉松弛剂和阿片类药物进行诱导,能够有效降低麻醉中的颅内压,增加脑灌注压并缩短患者麻醉后苏醒时间.%Objective; To discuss the effect of anesthesia induction with muscle relaxant and opioid on intracranial pressure and cerebral perfusion pressure in patients with intracranial tumors. Methods: A total of 80 patients with intracranial tumors receiving surgical therapy from March 2008 to March 2011 were randomly divided into two groups: experimental group and control group. The patients in experimental group underwent anesthesia induction with muscle relaxant ( succinylcholine) and opioid (fentanyl) before conventional general anesthesia, and those in control group received conventional general anesthesia only. The intracranial pressure and cerebral perfusion pressure were observed for all patients. Results: Compared with control group, the intracranial pressure, cerebral perfusion pressure and postoperative analepsia time of patients in experimental group before operation, 20 and 40 min after starting of operation, and after finishing surgery were obviously different (P <0. 05). Conclusion:The anesthesia induction with muscle relaxant and opioid before conventional general anesthesia can decrease the intrao-perative intracranial pressure effectively, increase cerebral perfusion pressure and shorten postanesthesia analepsia time.

  9. Intracranial Pressure Elevation 24 Hours after Ischemic Stroke in Aged Rats is Prevented by Early, Short Hypothermia Treatment

    Directory of Open Access Journals (Sweden)

    Lucy Anne Murtha

    2016-05-01

    Full Text Available Stroke is predominantly a senescent disease, yet most preclinical studies investigate treatment in young animals. We recently demonstrated that short-duration hypothermia-treatment completely prevented the dramatic intracranial pressure (ICP rise seen post-stroke in young rats. Here, our aim was to investigate whether a similar ICP rise occurs in aged rats and to determine whether short-duration hypothermia is an effective treatment in aged animals. Experimental Middle Cerebral Artery occlusion (MCAo - 3 hour occlusion was performed on male Wistar rats aged 19-20 months. At one hour after stroke-onset, rats were randomized to 2.5 hours hypothermia-treatment (32.5 °C or normothermia (37 °C. ICP was monitored at baseline, for 3.5 hours post-occlusion, and at 24 hours post-stroke. Infarct and edema volumes were calculated from histology. Baseline pre-stroke ICP was 11.2 ± 3.3 mmHg across all animals. Twenty-four hours post-stroke, ICP was significantly higher in normothermic animals compared to hypothermia-treated animals (27.4 ± 18.2 mmHg vs. 8.0 ± 5.0 mmHg, p = 0.03. Infarct and edema volumes were not significantly different between groups. These data demonstrate ICP may also increase 24 hours post-stroke in aged rats, and that short-duration hypothermia treatment has a profound and sustained preventative effect. These findings may have important implications for the use of hypothermia in clinical trials of aged stroke patients.

  10. Effects of dexamethasone and cox inhibitors on intracranial pressure and cerebral perfusion in the lipopolysaccharide treated rats with hyperammonemia.

    Directory of Open Access Journals (Sweden)

    Johan Rohde

    Full Text Available Systemic inflammation may affect the brain by aggravating the stage of encephalopathy and increasing intracranial pressure (ICP especially if liver insufficiency with hyperammonemia is present. The aim of this study was to determine if the influence of concomitant hyperammonemia and lipopolysaccharide (LPS on the brain can be prevented by dexamethasone and cyclooxygenase (COX inhibitors.Fifty-four male Wistar rats, 6 in each group, were divided into the following groups: Saline+ saline; LPS (2 mg/kg+saline; LPS+indomethacin (10 mg/kg; LPS+diclofenac (10mg/kg; LPS+dexamethasone (2mg/kg in experiment A. Experiment-B included the following groups: LPS+NH3 (140 μmol/kg/min+saline; LPS+NH3+indomethacin; LPS+NH3+diclofenac and LPS+NH3+dexamethasone. ICP was monitored via a catheter placed in cisterna magna and changes in CBF were recorded by laser Doppler flowmetry.LPS with and without NH3 induced a similar increase in plasma 6-keto-prostaglandin-F1α (6-keto-PGF1α concentration together with a concomitant rise in CBF and ICP. Indomethacin and diclofenac prevented the increase in ICP by LPS alone, and with the addition of NH3 the increase in both CBF and ICP, which was associated with a decrease in 6-keto-PGF1α. Dexamethasone only reduced the LPS induced increase in ICP but not CBF, and partly the 6-keto-PGF1α plasma concentration in the combined setup.These data indicate that activation of cycloooxygenases is of central importance for development of cerebral hyperemia and high ICP during concomitant systemic inflammation and hyperammonemia.

  11. Método para registro continuo da pressão intracraniana A method for continuous monitoring of the intracranial pressure

    Directory of Open Access Journals (Sweden)

    Henrique S. Ivamoto

    1975-06-01

    Full Text Available Pacientes com hipertensão intracraniana aguda podem ser melhor manipulados se a pressão intracraniana for constantemente medida. Uma série de 91 pacientes com traumatismos cranio-encefálicos agudos, hemorragia subaracnóidea, encefalite, hemorragia intracerebral, ou intoxicação por monóxido de carbono foi acompanhada usando o interruptor a pressão de Numoto por um método aqui descrito. O principal benefício tem sido o conhecimento do valor da pressão intracraniana a todo momento e a detecção rápida de elevações da pressão. Complicações se limitaram a 3 casos de infecção. Dois deles foram pequenas coleções purulentas no ponto de saída do tubo no couro cabeludo. Um paciente com uma fratura craniana exposta, laceração cerebral e hematoma intracerebral desenvolveu uma infecção da ferida operatoria e abscesso cerebral que requereu drenagem.Patients suffering acute intracranial pressure increases can be more advantageously handled if the intracranial pressure is constantly monitored. 91 patients with acute head injuries, hydrocephalus, cerebral infarction, subarachnoid hemorrhage, encephalitis, intracerebral hemorrhage, or carbon monoxide intoxication have been so monitored by using the Numoto pressure switch by a method herein described. The main advantage has been the knowledge of the level of intracranial pressure at any given time and the early detection of a rising pressure when this phenomenon occurred. There were no complications except for 3 cases of infection. Two of these cases were minor purulent collections only at the site of exit of the tube in the scalp. One patient with a compound wound, cerebral laceration, and intracerebral hematoma developed a wound infection and brain abscess which required drainage.

  12. Intracranial pressure monitoring in pediatric and adult patients with hydrocephalus and tentative shunt failure: a single-center experience over 10 years in 146 patients.

    Science.gov (United States)

    Sæhle, Terje; Eide, Per Kristian

    2015-05-01

    OBJECT In patients with hydrocephalus and shunts, lasting symptoms such as headache and dizziness may be indicative of shunt failure, which may necessitate shunt revision. In cases of doubt, the authors monitor intracranial pressure (ICP) to determine the presence of over- or underdrainage of CSF to tailor management. In this study, the authors reviewed their experience of ICP monitoring in shunt failure. The aims of the study were to identify the complications and impact of ICP monitoring, as well as to determine the mean ICP and characteristics of the cardiac-induced ICP waves in pediatric versus adult over- and underdrainage. METHODS The study population included all pediatric and adult patients with hydrocephalus and shunts undergoing diagnostic ICP monitoring for tentative shunt failure during the 10-year period from 2002 to 2011. The patients were allocated into 3 groups depending on how they were managed following ICP monitoring: no drainage failure, overdrainage, or underdrainage. While patients with no drainage failure were managed conservatively without further actions, over- or underdrainage cases were managed with shunt revision or shunt valve adjustment. The ICP and ICP wave scores were determined from the continuous ICP waveforms. RESULTS The study population included 71 pediatric and 75 adult patients. There were no major complications related to ICP monitoring, but 1 patient was treated for a postoperative superficial wound infection and another experienced a minor bleed at the tip of the ICP sensor. Following ICP monitoring, shunt revision was performed in 74 (51%) of 146 patients, while valve adjustment was conducted in 17 (12%) and conservative measures without any actions in 55 (38%). Overdrainage was characterized by a higher percentage of episodes with negative mean ICP less than -5 to -10 mm Hg. The ICP wave scores, in particular the mean ICP wave amplitude (MWA), best differentiated underdrainage. Neither mean ICP nor MWA levels showed any

  13. A microwave pressure sounder. [for remote measurement of atmospheric pressure

    Science.gov (United States)

    Peckham, G. E.; Flower, D. A.

    1981-01-01

    A technique for the remote measurement of atmospheric surface pressure will be described. Such measurements could be made from a satellite in polar orbit and would cover many areas for which conventional meteorological data are not available. An active microwave instrument is used to measure the strength of return echoes from the ocean surface at a number of frequencies near the 60 GHz oxygen absorption band. Factors which affect the accuracy with which surface pressure can be deduced from these measurements will be discussed and an instrument designed to test the method by making measurements from an aircraft will be described.

  14. Intra-Operative Fluid Management in Adult Neurosurgical Patients Undergoing Intracranial Tumour Surgery: Randomised Control Trial Comparing Pulse Pressure Variance (PPV) and Central Venous Pressure (CVP)

    Science.gov (United States)

    Salins, Serina Ruth; Kumar, Amar Nandha; Korula, Grace

    2016-01-01

    Introduction Fluid management in neurosurgery presents specific challenges to the anaesthesiologist. Dynamic para-meters like Pulse Pressure Variation (PPV) have been used successfully to guide fluid management. Aim To compare PPV against Central Venous Pressure (CVP) in neurosurgical patients to assess hemodynamic stability and perfusion status. Materials and Methods This was a single centre prospective randomised control trial at a tertiary care centre. A total of 60 patients undergoing intracranial tumour excision in supine and lateral positions were randomised to two groups (Group 1, CVP n=30), (Group 2, PPV n=30). Intra-operative fluid management was titrated to maintain baseline CVP in Group 1(5-10cm of water) and in Group 2 fluids were given to maintain PPV less than 13%. Acid base status, vital signs and blood loss were monitored. Results Although intra-operative hypotension and acid base changes were comparable between the groups, the patients in the CVP group had more episodes of hypotension requiring fluid boluses in the first 24 hours post surgery. {CVP group median (25, 75) 2400ml (1850, 3110) versus PPV group 2100ml (1350, 2200) p=0.03} The patients in the PPV group received more fluids than the CVP group which was clinically significant. {2250 ml (1500, 3000) versus 1500ml (1200, 2000) median (25, 75) (p=0.002)}. The blood loss was not significantly different between the groups The median blood loss in the CVP group was 600ml and in the PPV group was 850 ml; p value 0.09. Conclusion PPV can be used as a reliable index to guide fluid management in neurosurgical patients undergoing tumour excision surgery in supine and lateral positions and can effectively augment CVP as a guide to fluid management. Patients in PPV group had better hemodynamic stability and less post operative fluid requirement. PMID:27437329

  15. Reliability of cranial CT versus intracerebral pressure measurement for the evaluation of generalised cerebral oedema in children

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, W.; Beck, R.; Behrmann, C.; Spielmann, R.P. [Department of Diagnostic Radiology, University Hospital Halle-Wittenberg, 06 097 Halle (Germany); Schobess, A. [Department of Pediatrics, University Hospital Halle-Wittenberg, 06097 Halle (Germany)

    2000-07-01

    Objective. To examine the extent to which intracranial pressure (ICP) in children after severe brain trauma can be determined by cranial CT. Materials and methods. Two experienced paediatric radiologists, without any knowledge of the clinical symptoms, evaluated 124 CT scans from 65 children (average age 5.4 years) who underwent intracranial measurement of their cerebral pressure. Results. CT had high sensitivity (99.1%) for 'high cerebral pressure' but a much lower specificity (78.1%). The examiners tended to estimate ICP as 'high' even when actual ICP was low. Since therapy for lowering cerebral pressure involves potential risks, actual cerebral pressure measurement, particularly in children, should be considered before intervention (e. g. hyperventilation or trepanation). We report the change in different intracerebral fluid compartments with varying cerebral pressure and modifications of the density of the brain tissue in an inter- and intraobserver comparison. Conclusion. The radiologist cannot differentiate, for methodological reasons, between a change in the intracranial fluid compartments not associated with a change in ICP and one in which it is critically elevated. Before any interventional treatments such as decompression-trepanation or hyperventilation are instituted, measurement of ICP should be considered, especially in children. (orig.)

  16. Intracranial pressure elevation reduces flow through collateral vessels and the penetrating arterioles they supply. A possible explanation for 'collateral failure' and infarct expansion after ischemic stroke.

    Science.gov (United States)

    Beard, Daniel J; McLeod, Damian D; Logan, Caitlin L; Murtha, Lucy A; Imtiaz, Mohammad S; van Helden, Dirk F; Spratt, Neil J

    2015-05-01

    Recent human imaging studies indicate that reduced blood flow through pial collateral vessels ('collateral failure') is associated with late infarct expansion despite stable arterial occlusion. The cause for 'collateral failure' is unknown. We recently showed that intracranial pressure (ICP) rises dramatically but transiently 24 hours after even minor experimental stroke. We hypothesized that ICP elevation would reduce collateral blood flow. First, we investigated the regulation of flow through collateral vessels and the penetrating arterioles arising from them during stroke reperfusion. Wistar rats were subjected to intraluminal middle cerebral artery (MCA) occlusion (MCAo). Individual pial collateral and associated penetrating arteriole blood flow was quantified using fluorescent microspheres. Baseline bidirectional flow changed to MCA-directed flow and increased by >450% immediately after MCAo. Collateral diameter changed minimally. Second, we determined the effect of ICP elevation on collateral and watershed penetrating arteriole flow. Intracranial pressure was artificially raised in stepwise increments during MCAo. The ICP increase was strongly correlated with collateral and penetrating arteriole flow reductions. Changes in collateral flow post-stroke appear to be primarily driven by the pressure drop across the collateral vessel, not vessel diameter. The ICP elevation reduces cerebral perfusion pressure and collateral flow, and is the possible explanation for 'collateral failure' in stroke-in-progression.

  17. Foot Plantar Pressure Measurement System: A Review

    Directory of Open Access Journals (Sweden)

    Yufridin Wahab

    2012-07-01

    Full Text Available Foot plantar pressure is the pressure field that acts between the foot and the support surface during everyday locomotor activities. Information derived from such pressure measures is important in gait and posture research for diagnosing lower limb problems, footwear design, sport biomechanics, injury prevention and other applications. This paper reviews foot plantar sensors characteristics as reported in the literature in addition to foot plantar pressure measurement systems applied to a variety of research problems. Strengths and limitations of current systems are discussed and a wireless foot plantar pressure system is proposed suitable for measuring high pressure distributions under the foot with high accuracy and reliability. The novel system is based on highly linear pressure sensors with no hysteresis.

  18. On output measurements via radiation pressure

    DEFF Research Database (Denmark)

    Leeman, S.; Healey, A.J.; Forsberg, F.;

    1990-01-01

    It is shown, by simple physical argument, that measurements of intensity with a radiation pressure balance should not agree with those based on calorimetric techniques. The conclusion is ultimately a consequence of the circumstance that radiation pressure measurements relate to wave momentum, whi...

  19. 小儿颅内压增高的临床治疗%The Clinical Treatment on Children With Increased Intracranial Pressure

    Institute of Scientific and Technical Information of China (English)

    包明侠

    2015-01-01

    Objective To study the curative effect on children with increased intracranial pressure. Methods 24 cases of patients of children with increased intracranial pressure were chosen from March 2012 to June 2014,and the treatment information was analysed. Results 12 cases of patients were returned to normal 5~7 days after the treatment,the symptoms of 8 patients were disappeared 4~5 weeks later. There were 3 patients who got better and 1 case was disability,there was no death. Conclusion It is very important to treat the children increased intracranial pressure at an early time,it wil buy time for treatment and can improve the prognosis,and can also avoid the complications or death.%目的:探讨小儿颅内压增高的临床疗效。方法选取2012年3月~2014年6月收治的颅内压增高患儿24例临床治疗方法资料进行分析。结果本组收治的颅内压增高24例,5~7天恢复正常12例,4~5周症状消失8例,好转3例,致残1例,无死亡。结论颅内压增高症的早期诊断非常重要,可以为及时治疗争取时间,从而改善预后,避免出现后遗症或死亡。

  20. Measuring Viscosities of Gases at Atmospheric Pressure

    Science.gov (United States)

    Singh, Jag J.; Mall, Gerald H.; Hoshang, Chegini

    1987-01-01

    Variant of general capillary method for measuring viscosities of unknown gases based on use of thermal mass-flowmeter section for direct measurement of pressure drops. In technique, flowmeter serves dual role, providing data for determining volume flow rates and serving as well-characterized capillary-tube section for measurement of differential pressures across it. New method simple, sensitive, and adaptable for absolute or relative viscosity measurements of low-pressure gases. Suited for very complex hydrocarbon mixtures where limitations of classical theory and compositional errors make theoretical calculations less reliable.

  1. Beam Loss Diagnostics Based on Pressure Measurements

    CERN Document Server

    Weinrich, U

    2003-01-01

    The GSI is operating a heavy ion synchrotron, which is currently undergoing an upgrade towards higher beam intensities. It was discovered that beam losses induce a significant pressure increase in the vacuum system. In order to detect the time constants of the pressure increase and decrease, fast total pressure measurements were put into operation. With the recently installed partial pressure diagnostics it is also possible to follow up which types of molecules are released. The presentation will focus on the different techniques applied as well as on some measurement results. The potential and difficulties of this diagnostic tool will also be discussed.

  2. Fentanyl and Midazolam Are Ineffective in Reducing Episodic Intracranial Hypertension in Severe Pediatric Traumatic Brain Injury.

    Science.gov (United States)

    Welch, Timothy P; Wallendorf, Michael J; Kharasch, Evan D; Leonard, Jeffrey R; Doctor, Allan; Pineda, Jose A

    2016-04-01

    To evaluate the clinical effectiveness of bolus-dose fentanyl and midazolam to treat episodic intracranial hypertension in children with severe traumatic brain injury. Retrospective cohort. PICU in a university-affiliated children's hospital level I trauma center. Thirty-one children 0-18 years of age with severe traumatic brain injury (Glasgow Coma Scale score of ≤ 8) who received bolus doses of fentanyl and/or midazolam for treatment of episodic intracranial hypertension. None. The area under the curve from high-resolution intracranial pressure-time plots was calculated to represent cumulative intracranial hypertension exposure: area under the curve for intracranial pressure above 20 mm Hg (area under the curve-intracranial hypertension) was calculated in 15-minute epochs before and after administration of fentanyl and/or midazolam for the treatment of episodic intracranial hypertension. Our primary outcome measure, the difference between predrug and postdrug administration epochs (Δarea under the curve-intracranial hypertension), was calculated for all occurrences. We examined potential covariates including age, injury severity, mechanism, and time after injury; time after injury correlated with Δarea under the curve-intracranial hypertension. In a mixed-effects model, with patient as a random effect, drug/dose combination as a fixed effect, and time after injury as a covariate, intracranial hypertension increased after administration of fentanyl and/or midazolam (overall aggregate mean Δarea under the curve-intracranial hypertension = +17 mm Hg × min, 95% CI, 0-34 mm Hg × min; p = 0.04). The mean Δarea under the curve-intracranial hypertension increased significantly after administration of high-dose fentanyl (p = 0.02), low-dose midazolam (p = 0.006), and high-dose fentanyl plus low-dose midazolam (0.007). Secondary analysis using age-dependent thresholds showed no significant impact on cerebral perfusion pressure deficit (mean Δarea under the curve

  3. Application and nursing of intracranial pressure monitoring in children with craniocerebral injury%颅内压监护在小儿颅脑损伤中的应用及护理

    Institute of Scientific and Technical Information of China (English)

    林丽; 谢静慧; 魏晓玲; 周玉华

    2016-01-01

    Objective To investigate the effect and nursing methods of intracranial pressure monitoring in children with craniocerebral injury. Methods 40 children with craniocerebral injury from March 2011 to December 2015 cured in our hospital were selected and randomly divided into two groups, 20 cases were divided into control group and mainly treated with routine neurosurgery nursing, which monitored of vital signs by observing the change of consciousness, pupil and physical activity, and then prescribed medication. The other 20 cases were divided into experimental group and applied with intracranial pressure monitor, through the correct use of intracranial pressure monitor, according to the data of intracranial pressure, pre sexual found the dynamic changes of intracranial pressure, so as to guide the clinical medication, forward-looking taken a series of interventions for intracranial pressure increased nursing measures on the basis of routine nursing. Results The experimental group did not appear mortality (0) and the control group had 2 cases (10.00%), and there were significant difference between the two groups (P<0.05). Experimental group accounted for 1 (5.00%) in rebleeding, the control group occurred in 3 cases of rebleeding (15.00%), and there were significant difference between the two groups (P < 0.05). Experimental group accounted for 1 case of severely disabled children (5.00%), the control group had 4 cases of severely disabled children (20.00%), and there were significant difference between the two groups (P < 0.05). In the days of hospitalization, the average days of hospitalization of experimental group was (9.4±3.4)days, which was significantly lower than that of control group with (16.5±5.8) days, and there were significant difference between the two groups (P < 0.05). Conclusion The implementation of intracranial pressure monitoring in patients with severe brain injury is helpful to the early detection of intracranial pressure, to guide medical

  4. Measuring preoperative anxiety in patients with intracranial tumors: the Amsterdam preoperative anxiety and information scale.

    Science.gov (United States)

    Goebel, Simone; Kaup, Lea; Mehdorn, Hubertus Maximilian

    2011-10-01

    Preoperative anxiety is a major problem in patients with brain tumors and is of high clinical relevance. However, to date no instruments have been validated for the assessment of preoperative anxiety for this patient group. The Amsterdam Preoperative Anxiety and Information Scale (APAIS) has shown promising results for the assessment of preoperative anxiety. The aim of this study was to determine its psychometric properties and the optimal cutoff score for patients with intracranial tumors to make it applicable in the neurosurgical setting. The sample totaled 180 neurosurgical patients with intracranial tumors. Patients were administered the APAIS along with the Hospital Anxiety and Depression Scale as the gold standard against which the APAIS was compared. Patients scoring 11 or above in the anxiety subscale of the Hospital Anxiety and Depression Scale were defined as clinical cases having anxiety. The psychometric properties of the APAIS were evaluated for a postulated 2-factor structure, Cronbach α, and correlations. The postulated 2-factor structure could not be replicated. Instead, we found a 3-factor solution (anxiety about the operation, anxiety about the anesthesia, information requirement). The area under the receiver operating characteristics curve ranged from ≥0.65 to ≥0.77. Optimal cutoff scores were calculated. The cutoff score for the anxiety scale was ≥10 for the whole sample and men only, and was ≥11 for women only. Analysis of the psychometric properties yielded satisfactory results (eg. Cronbach α for the anxiety scale >0.84). Despite its brevity, the APAIS is valid and recommendable for the assessment of preoperative anxiety in patients with intracranial tumors. As this is the first validation study focusing on patients with severe diseases and major surgeries, we recommend the application of our cutoff scores also for patients similar to our study population with regard to disease and surgery severity.

  5. High Blood Pressure Increases the Risk of Poor Outcome at Discharge and 12-month Follow-up in Patients with Symptomatic Intracranial Large Artery Stenosis and Occlusions: Subgroup analysis of the CICAS Study.

    Science.gov (United States)

    Yu, Dan-Dan; Pu, Yue-Hua; Pan, Yue-Song; Zou, Xin-Ying; Soo, Yannie; Leung, Thomas; Liu, Li-Ping; Wang, David Z; Wong, Ka-Sing; Wang, Yi-Long; Wang, Yong-Jun

    2015-06-01

    The purpose of this study was to discuss the relationship between blood pressure and prognosis of patients with symptomatic intracranial arterial stenosis. Data on 2426 patients with symptomatic intracranial large artery stenosis and occlusion who participated in the Chinese Intracranial Atherosclerosis (CICAS) study were analyzed. According to the JNC 7 criteria, blood pressure of all patients was classified into one of the four subgroups: normal, prehypertension, hypertension stage I, and hypertension stage II. Poor outcomes were defined as death and functional dependency (mRS 3-5) at discharge or at 1 year. For patients with intracranial stenosis of 70% to 99%, the rate of poor outcome at discharge was 19.3%, 23.5%, 26.8%, and 39.8% (P = 0.001) for each blood pressure subgroup. For patients with intracranial large artery occlusion, the rates were 17.6%, 22.1%, 29.5%, and 49.8%, respectively (P blood pressure subgroup and 11.6%, 21.5%, 23.9%, 35.1% (P risk of poor outcome at discharge and 12-month follow-up. © 2015 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.

  6. Blade Tip Pressure Measurements Using Pressure Sensitive Paint

    Science.gov (United States)

    Wong, Oliver D.; Watkins, Anthony Neal; Goodman, Kyle Z.; Crafton, James; Forlines, Alan; Goss, Larry; Gregory, James W.; Juliano, Thomas J.

    2012-01-01

    This paper discusses the application of pressure sensitive paint using laser-based excitation for measurement of the upper surface pressure distribution on the tips of rotor blades in hover and simulated forward flight. The testing was conducted in the Rotor Test Cell and the 14- by 22-ft Subsonic Tunnel at the NASA Langley Research Center on the General Rotor Model System (GRMS) test stand. The Mach-scaled rotor contained three chordwise rows of dynamic pressure transducers for comparison with PSP measurements. The rotor had an 11 ft 1 in. diameter, 5.45 in. main chord and a swept, tapered tip. Three thrust conditions were examined in hover, C(sub T) = 0.004, 0.006 and 0.008. In forward flight, an additional thrust condition, C(sub T) = 0.010 was also examined. All four thrust conditions in forward flight were conducted at an advance ratio of 0.35.

  7. Assessment of changes in Intracranial Pressure (ICP) after the implementation of therapeutic measures for Intracranial Hypertation (IH)

    OpenAIRE

    Nikoletta Arapoglou; Aikaterini Marvaki; Eleni Dokoutsidou; Kadda Olga

    2014-01-01

    The Traumatic Brain Injury (TBI) constitutes the leading cause of death and permanent disability in all age groups and, by far, at ages 19-27 years. The morbidity and mortality remain high and depend on the neurological status of patients at admission, the treatment in the Intensive Care Unit (ICU), surgery and postoperative rehabilitation and recovery. The prevention and treatment factors that may maintain or exacerbate the IH is a very important and fundamental issue in neurological intensi...

  8. Centrifugal pump inlet pressure site affects measurement.

    Science.gov (United States)

    Augustin, Simon; Horton, Alison; Butt, Warwick; Bennett, Martin; Horton, Stephen

    2010-09-01

    During extracorporeal life support (ECLS), blood is exposed to a myriad of unphysiological factors that can affect outcome. One aspect of this is the sub-atmospheric pressure generated by the ECLS pump and imparted to blood elements along the pump inlet line. This pressure can be measured on the inlet line close to the pump head by adding a connector, or at the venous cannula connection site. We compared the two measurement sites located at both points; between the venous cannula-inlet tubing and inlet tubing-pump, with a range of cannulae and flows. We also investigated the effects on inlet pressure from pump afterload and increasing inlet tubing length.

  9. Measuring Pressure Drop Under Non Ideal Conditions

    Directory of Open Access Journals (Sweden)

    Austin M

    2014-12-01

    Full Text Available The method of measurement of the pressure drop (PD of cigarette filter rods and the draw resistance of cigarettes is defined in ISO 6565-2002 (1. This standard defines the calibration and use of a transfer standard to calibrate the measuring instrument and also defines the measurement procedure for cigarette and filter samples. The procedure described in the standard assumes that the measurement conditions are constant and that the sample is in equilibrium with the measurement environment.

  10. Pressure measurements in magnetic-fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Dylla, H.F.

    1981-11-01

    Accurate pressure measurements are important in magnetic fusion devices for: (1) plasma diagnostic measurements of particle balance and ion temperature; (2) discharge cleaning optimization; (3) vacuum system performance; and (4) tritium accountability. This paper reviews the application, required accuracy, and suitable instrumentation for these measurements. Demonstrated uses of ionization-type and capacitance-diaphragm gauges for various pressure and gas-flow measurements in tokamaks are presented, with specific reference to the effects of magnetic fields on gauge performance and the problems associated with gauge calibration.

  11. Pancreas tumor interstitial pressure catheter measurement

    Science.gov (United States)

    Nieskoski, Michael D.; Gunn, Jason; Marra, Kayla; Trembly, B. Stuart; Pogue, Brian W.

    2016-03-01

    This paper highlights the methodology in measuring interstitial pressure in pancreatic adenocarcinoma tumors. A Millar Mikrotip pressure catheter (SPR-671) was used in this study and a system was built to amplify and filter the output signal for data collection. The Millar pressure catheter was calibrated prior to each experiment in a water column at 37°C, range of 0 to 60 inH2O (112 mmHg), resulting in a calibration factor of 33 mV / 1 inH2O. The interstitial pressures measured in two orthotopically grown pancreatic adenocarcinoma tumor were 57 mmHg and 48 mmHg, respectively. Verteporfin uptake into the pancreatic adenocarcinoma tumor was measured using a probe-based experimental dosimeter.

  12. New pressure cell for ultrasonic measurements

    Science.gov (United States)

    Kepa, Michal; Huxley, Andrew; Kamenev, Konstantin

    2013-06-01

    Ultrasonic interferometry at high pressure remains a technical challenge as the small sample space requires the application of very high-frequency ultrasound. Here we present the design of a new cell developed specifically for ultrasonic measurements of single crystals at low temperatures (2K) and high pressures (5GPa). The design allows greater sample space (compared to a conventional diamond anvil cell) and simultaneous measurement of ultrasonic attenuation and velocities. Coupling the fine transducers to spherical sapphire anvils reduces background and enables different polarizations of the ultrasonic wave to be measured at the same pressure and temperature conditions. The results are used to deduce the elastic, electronic and magnetic properties of a crystal. The finite element analysis of the cell together with the pressure calibration curves and test data taken on UGe2 are presented.

  13. 显微镜下颅内动脉瘤夹闭术中高血压与颅内压增高的护理%Nursing Care of Hypertension and Intracranial Pressure for Patients With Intracranial Aneurysm Surgery Under the Microscope

    Institute of Scientific and Technical Information of China (English)

    陈淑惠; 张萍; 周亚梅

    2015-01-01

    Objective This paper aimed to research and discuss about the influence from the intraoperative nursing of hypertension and increased intracranial pressure on the clinical results of intracranial aneurysm surgery under the microscope.Methods100 patients who were admitted to our hospital for intracranial aneurysm surgery under the microscope from January 2014 to March 2015 and nursing of hypertension and increased intracranial pressure was conducted on them during the surgery. And then,the effects of the operational nursing were analyzed.ResultsThe operations of 96 patients were successful,accounting for a success rate of 96%,while there were complications in four cases,accounting for 4.0%. Conclusion The intraoperative nursing of hypertension and increased intracranial pressure can provide excellent clinical results on intracranial aneurysm surgery under the microscope.%目的:研究探讨术中高血压和颅内压增高护理对显微镜下颅内动脉瘤夹闭术临床治疗效果的影响。方法选取我院2014年1月~2015年3月收治的100例行显微镜下颅内动脉瘤夹闭术手术的患者,在手术中进行高血压和颅内压增高护理,分析手术护理的效果。结果96例患者手术成功,成功率占96.0%。有4例发生并发症占4.0%。结论术中高血压和颅内压增高护理对显微镜下颅内动脉瘤夹闭术临床护理疗效果优良。

  14. Working meeting on blood pressure measurement: suggestions for measuring blood pressure to use in populations surveys.

    Science.gov (United States)

    2003-11-01

    As part of the Pan American Hypertension Initiative (PAHI), the Pan American Health Organization and the National Heart, Lung, and Blood Institute of the National Institutes of Health of the United States of America conducted a working meeting to discuss blood pressure (BP) measurement methods used in various hypertension prevalence surveys and clinical trials, with the objective of developing a BP measurement protocol for use in hypertension prevalence surveys in the Americas. No such common protocol has existed in the Americas, so it has been difficult to compare hypertension prevention and intervention strategies. This piece describes a proposed standard method for measuring blood pressure for use in population surveys in the Region of the Americas. The piece covers: considerations for developing a common blood pressure measurement protocol, critical issues in measuring blood pressure in national surveys, minimum procedures for blood pressure measurement during surveillance, and quality assessment of blood pressure.

  15. Intracranial haemorrhage

    African Journals Online (AJOL)

    His interests include vascular neurosurgery and spinal deformities. ... he returned to specialise in neurosurgery after time spent working abroad. ... at Groote Schuur Hospital, where his major interests are skull base surgery and ... intracranial bleed is hypertension – this is an ... cerebellar signs and symptoms or with raised.

  16. Untethered photonic sensor for wall pressure measurement.

    Science.gov (United States)

    Manzo, Maurizio; Ioppolo, Tindaro

    2015-05-15

    In this Letter, we study a novel untethered photonic wall pressure sensor that uses as sensing element a dome-shaped micro-scale laser. Since the sensor does not require any optical or electrical cabling, it allows measurements where cabling tends to be problematic. The micro-laser is made by a mixture of Trimethylolpropane Tri(3-mercaptopropionate), commercial name THIOCURE and Polyethylene (glycol) Diacrylate (PEGDA) mixed with a solution of rhodamine 6G. Two different volume ratios between the THIOCURE and the PEGDA are studied, since different ratios lead to different mechanical properties. In addition, two different sensor configurations are presented: (i) sensor coupled to a membrane, that allows differential wall pressure measurement and (ii) sensor without membrane that allows absolute wall pressure measurement. The sensitivity plots are presented in the paper for both sensor configurations and polymer ratios.

  17. Osmolality of Cerebrospinal Fluid from Patients with Idiopathic Intracranial Hypertension (IIH)

    DEFF Research Database (Denmark)

    Wibroe, Elisabeth A; Yri, Hanne M; Jensen, Rigmor H

    2016-01-01

    INTRODUCTION: Idiopathic intracranial hypertension (IIH) is a disorder of increased intracranial fluid pressure (ICP) of unknown etiology. This study aims to investigate osmolality of cerebrospinal fluid (CSF) from patients with IIH. METHODS: We prospectively collected CSF from individuals referred...... on suspicion of IIH from 2011-2013. Subjects included as patients fulfilled Friedman and Jacobson's diagnostic criteria for IIH. Individuals in whom intracranial hypertension was refuted were included as controls. Lumbar puncture with ICP measurement was performed at inclusion and repeated for patients after...

  18. Low cerebrospinal fluid pressure in the pathogenesis of primary open-angle glaucoma: epiphenomenon or causal relationship? The Beijing Intracranial and Intraocular Pressure (iCOP) study.

    Science.gov (United States)

    Wang, Ningli; Yang, Diya; Jonas, Jost B

    2013-01-01

    Previous experimental and clinical investigations have suggested that some patients with primary open-angle glaucoma may have an abnormally low orbital cerebrospinal fluid pressure (CSFP). A meta-analysis of available clinical data showed a marked overlap in lumbar CSFP measurements between patients with normal-tension glaucoma and healthy subjects, so that the question arises as to which additional factors play a role in the pathogenesis of glaucomatous optic neuropathy.

  19. Effects of Simulation With Problem-Based Learning Program on Metacognition, Team Efficacy, and Learning Attitude in Nursing Students: Nursing Care With Increased Intracranial Pressure Patient.

    Science.gov (United States)

    Lee, Myung-Nam; Nam, Kyung-Dong; Kim, Hyeon-Young

    2017-03-01

    Nursing care for patients with central nervous system problems requires advanced professional knowledge and care skills. Nursing students are more likely to have difficulty in dealing with adult patients who have severe neurological problems in clinical practice. This study investigated the effect on the metacognition, team efficacy, and learning attitude of nursing students after an integrated simulation and problem-based learning program. A real scenario of a patient with increased intracranial pressure was simulated for the students. The results showed that this method was effective in improving the metacognitive ability of the students. Furthermore, we used this comprehensive model of simulation with problem-based learning in order to assess the consequences of student satisfaction with the nursing major, interpersonal relationships, and importance of simulation-based education in relation to the effectiveness of the integrated simulation with problem-based learning. The results can be used to improve the design of clinical practicum and nursing education.

  20. Side abutment pressure distribution by field measurement

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-guo; SONG Yang; HE Xing-hua; ZHANG Jian

    2008-01-01

    Given the 7123 working face in the Qidong Coal Mine of the Wanbei Mining Group, nine dynamic roof monitors were installed in the crossheading to measure the amount and velocity of roof convergence in different positions and at different times and three steel bored stress sensors were installed in the return airway to measure rock stress at depth. On the basis of this arrangement, the rule of change of the distribution of the side abutment pressure with the advance of the working face and movement of overlying strata was studied. The rule of change and the stability of rock stress at depth were measured. Secondly, the affected area and stability time of the side abutment pressure were also studied. The results show that: 1) During working, the face advanced distance was from 157 m to 99 m, the process was not effected by mining induced pressure. When the distance was 82 m, the position of peak stress was 5 m away from the coal wall. When the distance was 37 m, the position of peak stress away from the coal wall was about 15 m to 20 m and finally reached a steady state; 2) the time and the range of the peak of side rock pressure obtained from stress sensors were consistent with the results from the dynamic roof monitors; 3) the position of the peak pressure was 25 m away from the coal wall.

  1. Confounders of auscultatory blood pressure measurement.

    Science.gov (United States)

    Baker, R H; Ende, J

    1995-04-01

    The appropriate use of any test requires the clinician to appreciate that test's limitations. By recognizing the potential confounders of the auscultatory assessment of blood pressure, the clinician minimizes the likelihood of enacting therapeutic decisions based on inaccurate data. When approaching the treatment of a hypertensive patient, several points should be kept in mind. First, the measurement of persistent and severe hypertension in a patient receiving treatment who describes symptoms of orthostatic hypotension with apparently adequate standing blood pressure or who lacks corroborating retinal, echocardiographic, or electrocardiographic signs of hypertension should raise the concern of pseudohypertension or a white-coat response. Similarly, when one finds a normal or near-normal systolic blood pressure in a patient with a clinical picture consistent with severe hypertension, one should make a directed effort to look for an unrecognized auscultatory gap. Second, marked discrepancies in measurements as obtained by different operators or in different settings should raise concern of the white-coat response or methodologic errors by one operator, such as undercuffing, excessive pressure on the head of the stethoscope, rapid deflation of the cuff, or use of different arms. In treating hypertension in even the minimally obese patient, a special point must be made that an adequate size cuff be used for all blood pressure determinations. Third, when blood pressure is determined with the patient in any but the satndardized back-and-arm-supported seated position described above, the clinician should acknowledge the possibility that the position may alter the patient's classification. Fourth, the diagnosis and management of hypertension requires multiple measurements of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

    2014-01-01

    Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

  3. A System for Unsteady Pressure Measurements Revisited

    NARCIS (Netherlands)

    Tijdeman, H.; Spiering, R.M.E.J.

    2003-01-01

    An overview is presented of some recent developments in the field of the design of effective sound absorbers. The first part deals with the application of socalled coupled tubes. For this purpose use is made of a system originally applied for unsteady pressure measurements on oscillating wind tunnel

  4. Pore Pressure Measurements Inside Rubble Mound Breakwaters

    DEFF Research Database (Denmark)

    Helgason, Einar; Burcharth, H. F.; Grüne, Joachim

    2004-01-01

    The present paper presents pore pressure measurements from large scale model tests performed at the Large Wave Channel, Hannover, Germany and small scale model test performed at the Hydraulic & Coastal Engineering Laboratory, Aalborg University, Denmark. Information on pore pressure attenuation......, and compared to a damping model presented by Burcharth et al. (1999). Reasonable agreement is found when considering the difference in the grading and uniformity of the model core materials. Comparison between results obtained from small and large scale model tests showed no clear evidence of scale effects....

  5. How to measure intraocular pressure: applanation tonometry

    Directory of Open Access Journals (Sweden)

    Nick Astbury

    2012-01-01

    Full Text Available Unless there is a contraindication (e.g. trauma or corneal ulcer, all adults attending an eye unit should have their intraocular pressure (IOP measured. Many people with glaucoma have no symptoms and do not know they have the condition. All children who have had cataract surgery should also have their IOP measured at every follow-up visit, if possible. Finding glaucoma early allows treatment to be given which will preserve sight. Although elevated IOP is not the only sign of glaucoma, measuring it is simple and quick to do. Applanation tonometry, using a Goldmann tonometer at a slit lamp, is the preferred method (the ‘gold standard’.

  6. Oscillometric blood pressure measurement: progress and problems.

    Science.gov (United States)

    van Montfrans, G A

    2001-12-01

    Oscillometric blood pressure measurement has become very popular, but although a number of devices have now passed both the Association for the Advancement of Medical Instrumentation and British Hypertension Society criteria, complacency with the state of the technique is as yet premature. In individual subjects, a substantial number of readings may deviate more than a clinically relevant 5 mmHg in devices that have earned a British Hypertension Society grade A rating. The marketing of pressure-wave-simulating devices is a welcome development as monitors can now be tested for reproducibility; an intra-device standard deviation of less than 2 mmHg has been proposed as the limit. Authors suggest that these simulators are currently better suited to intra- than between-device testing since they are not yet fully confident that the simulated waveforms are indistinguishable from the man-made pressure waves. Simulators should, however, be incorporated into our standard validation protocols in order eventually to obviate the human, fallible, factor in the validation protocols. The currently employed maximal amplitude algorithm has many drawbacks as the parameter identification points for systolic and diastolic pressure depend on many factors, for example pulse pressure, heart rate and arterial stiffness. These errors have now been demonstrated in clinical studies. Modern pattern recognition algorithms are being constructed but have not yet produced convincing results. As repeatedly stated, the development of a more robust and more widely applicable algorithm than the maximal amplitude approach should be allocated a high priority.

  7. Measurement of Blood Flow in an Intracranial Artery Bypass From the Internal Maxillary Artery by Intraoperative Duplex Sonography.

    Science.gov (United States)

    Yu, Zaitao; Shi, Xiang'en; Brohi, Shams Raza; Qian, Hai; Liu, Fangjun; Yang, Yang

    2017-02-01

    This study explored the hemodynamic characteristics of a subcranial-intracranial bypass from the internal maxillary artery by measuring blood flow on intraoperative duplex sonography. The hemodynamic parameters of the internal maxillary artery (n = 20), radial artery (n = 20), internal maxillary artery-middle cerebral artery bypass (n = 42), and internal maxillary artery-posterior cerebral artery bypass (n = 9) were measured by intraoperative duplex sonography. There was no significant difference in the internal diameters of the internal maxillary and radial arteries (mean ± SD, 2.51 ± 0.34 versus 2.56 ± 0.22 mm; P = .648). The mean radial artery graft length for subcranial-intracranial bypasses was 88.5 ± 12.78 mm (95% confidence interval [CI], 80.8-90.2 mm). Internal maxillary artery-middle cerebral artery bypasses required a shorter radial artery graft than internal maxillary artery-posterior cerebral artery bypasses (77.8 ± 2.47 versus 104.8 ± 4.77 mm; P = .001). The mean flow volumes were 85.3 ± 18.5 mL/min (95% CI, 76.6-93.9 mL/min) for the internal maxillary artery, 72.6 ± 26.4 mL/min (95% CI, 64.3-80.9 mL/min) for internal maxillary artery-middle cerebral artery bypasses, and 45.4 ± 6.7 mL/min (95% CI, 40.7-50.0 mL/min) for internal maxillary artery-posterior cerebral artery bypasses. All grafts were opened after the success of the salvage procedures had been established, and the early patency rates (1 month after the operation) were 95% for internal maxillary artery-middle cerebral artery bypasses and 100% the internal maxillary artery-posterior cerebral artery bypasses. Measurement of blood flow by intraoperative sonography can be helpful in decision making and predicting graft patency and success after neurosurgical bypass procedures.

  8. Acute surgical management in idiopathic intracranial hypertension.

    LENUS (Irish Health Repository)

    Zakaria, Zaitun

    2012-01-01

    Idiopathic intracranial hypertension is a headache syndrome with progressive symptoms of raised intracranial pressure. Most commonly, it is a slow process where surveillance and medical management are the main treatment modalities. We describe herein an acute presentation with bilateral sixth nerve palsies, papilloedema and visual deterioration, where acute surgical intervention was a vision-saving operation.

  9. Unsteady Pressure and Velocity Measurements in Pumps

    Science.gov (United States)

    2006-11-01

    to reproduce the data with controlled experiments . For example, the rotor exit flow measured by means of a stationary high response probe will be...Turbomachinery by Means of High-Frequency Pressure Transducers. ASME, J. of Turbomachinery, Vol. 114, pp. 100-107. [3] Castorph, D. (1975): Messung ...Dreiß, A.; Kosyna, G. (1997): Experimental Investigations of Cavitation-States in a Radial Pump Impeller. JSME CENTENNIAL GRAND CONGRESS Proceedings of

  10. Idiopathic Intracranial Hypertension – Pathophysiology Based on Case Series

    Directory of Open Access Journals (Sweden)

    Ljubisavljević Srdjan

    2016-09-01

    Full Text Available According to the definition, idiopathic intracranial hypertension (IIH is a pathological state characterized by an increase in intracranial pressure; however, there are no obvious intracranial pathological processes. The pathophysiology of this disorder is not clear, although there are many reports related to it.

  11. Syphilis mimicking idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Yri, Hanne; Wegener, Marianne; Jensen, Rigmor

    2011-01-01

    Idiopathic intracranial hypertension (IIH) is a condition of yet unknown aetiology affecting predominantly obese females of childbearing age. IIH is a diagnosis of exclusion as raised cerebrospinal fluid pressure may occur secondary to numerous other medical conditions. An atypical phenotype...... or an atypical disease course should alert the physician to reevaluate a presumed IIH-diagnosis. The authors report a case of a 32-year-old non-obese male with intracranial hypertension, secondary to a syphilitic central nervous system infection, initially misdiagnosed as being idiopathic. Upon relevant...... antibiotic treatment, signs and symptoms of elevated intracranial pressure resolved completely. Syphilis is a rare, but very important, differential diagnosis that in this case was clinically indistinguishable from IIH....

  12. Cerebral venous etiology of intracranial hypertension and differentiation from idiopathic intracranial hypertension

    Directory of Open Access Journals (Sweden)

    Stefan Mircea Iencean

    2015-03-01

    Full Text Available This study presents the characteristics that distinguish between idiopathic intracranial hypertension (ICH and ICH caused by intracranial vascular damage. Twenty-one patients with ICH were included in this study. The analysis of the symptomatology correlated with the values of intracranial pressure, and the imaging findings revealed significant differences between these two types of ICH. ICH caused by intracranial venous vascular damage is named vascular ICH. Vascular ICH has a known etiology, such as cerebral vascular illness, and a relatively rapid increase in intracranial pressure of approximately 21 cmH2O and imaging findings show characteristic images of thrombosis or stenosis of the intracranial venous system, while all brain images (computed tomography, magnetic resonance imaging, angio-magnetic resonance imaging are normal in idiopathic ICH. The treatment of vascular ICH is etiologic, pathogenic, and symptomatic, but that of idiopathic ICH is only symptomatic.

  13. Cerebral venous etiology of intracranial hypertension and differentiation from idiopathic intracranial hypertension.

    Science.gov (United States)

    Iencean, Stefan Mircea; Poeata, Ion; Iencean, Andrei Stefan; Tascu, Alexandru

    2015-03-01

    This study presents the characteristics that distinguish between idiopathic intracranial hypertension (ICH) and ICH caused by intracranial vascular damage. Twenty-one patients with ICH were included in this study. The analysis of the symptomatology correlated with the values of intracranial pressure, and the imaging findings revealed significant differences between these two types of ICH. ICH caused by intracranial venous vascular damage is named vascular ICH. Vascular ICH has a known etiology, such as cerebral vascular illness, and a relatively rapid increase in intracranial pressure of approximately 21 cmH2O and imaging findings show characteristic images of thrombosis or stenosis of the intracranial venous system, while all brain images (computed tomography, magnetic resonance imaging, angio-magnetic resonance imaging) are normal in idiopathic ICH. The treatment of vascular ICH is etiologic, pathogenic, and symptomatic, but that of idiopathic ICH is only symptomatic. Copyright © 2015. Published by Elsevier Taiwan.

  14. Tandem pressure measurements in a hostile environment

    Science.gov (United States)

    Higgins, P. B.

    1981-03-01

    Both carbon gages and quartz gages were calibrated with gas guns utilizing thin flyers. Experiments are described which compare the response of the two types of gages to a nonplaner stress pulse generated by the detonation of an explosive, silver acetylide-silver nitrate. It was concluded from 18 pairs of gages tested at three impulse levels that detonation of the explosive at no less than 100 points square cm would produce equal peak stress currents from the two types of gages within 25 percent. Impulse derived by integrating the pressure time profile from the carbon gages mounted on quartz gages did not agree with ballistic pendulum impulse data, possibly because of early cracking of quartz beneath the carbon gage. However, similar integration of the pressure profile of carbon gages mounted on flat aluminum, extrapolated for long times along a theoretical curve, gave an impulse practically equal to the directly measured impulse.

  15. Intracranial endoscopy.

    Science.gov (United States)

    Schroeder, H W; Gaab, M R

    1999-04-15

    The authors' intention is to reduce the invasiveness of intracranial procedures while avoiding traumatization of brain tissue, to decrease the risk of neurological and mental deficits. Intracranial endoscopy is a minimally invasive technique that provides rapid access to the target via small burr holes without the need for brain retraction. Craniotomy as well as microsurgical brain splitting and dissection can often be avoided. Furthermore, because obstructed cerebrospinal fluid pathways can be physiologically restored, the need for shunt placement is eliminated. The ventricular system and subarachnoid spaces provide ideal conditions for the use of an endoscope. Therefore, a variety of disorders, such as hydrocephalus, small intraventricular lesions, and arachnoid and parenchymal cysts can be effectively treated using endoscopic techniques. With the aid of special instruments, laser fibers, and bipolar diathermy, even highly vascularized lesions such as cavernomas may be treated. Moreover, during standard microsurgical procedures, the endoscopic view may provide valuable additional information ("looking around a corner") about the individual anatomy that is not visible with the microscope. In transsphenoidal pituitary surgery, transseptal dissection can be avoided if an endonasal approach is taken. In the depth of the intrasellar space, the extent of tumor removal can be more accurately controlled, especially in larger tumors with para- and suprasellar growth. The combined use of endoscopes and computerized neuronavigation systems increases the accuracy of the approach and provides real-time control of the endoscope tip position and approach trajectory. In the future, the indications for neuroendoscopy will certainly expand with improved technical equipment.

  16. Comparison of remnant size in embolized intracranial aneurysms measured at follow-up with DSA and MRA

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Zbigniew; Strzesniewski, Piotr; Lasek, Wladyslaw [Nicolaus Copernicus University, Department of Radiology and Diagnostic Imaging, Collegium Medicum, Bydgoszcz (Poland); Beuth, Wojciech [University of Humanities and Economics in Wloclawek, Faculty of Health Sciences, Wloclawek (Poland)

    2012-12-15

    The possibility of recanalization and the need for retreatment are the most important limitations of intracranial aneurysm embolization. The purpose of the study was to compare the size of aneurysm remnants measured at follow-up with three-dimensional digital subtracted angiography (3D-DSA) and magnetic resonance angiography (MRA). Twenty-six aneurysms were found incompletely occluded in 72 consecutively examined patients at a follow-up after 3 months. The diameters and volume of aneurysm remnants were compared between 3D-DSA, time-of-flight MRA (TOF-MRA), contrast-enhanced TOF-MRA (CE-TOF-MRA), and contrast-enhanced MRA (CE-MRA) at 1.5 T. There was a significant correlation between remnant volumes calculated based on 3D-DSA and all MRA modalities. The intraobserver variability of the measurements ranged from 3.4 to 4.1 % and the interobserver variability from 5.8 to 7.3 %. There were no significant differences in the variability between the techniques. The mean residual filling volume ranged from 16.3 {+-} 19.0 mm{sup 3} in TOF-MRA to 30.5 {+-} 44.6 mm{sup 3} in 3D-DSA (P < 0.04). Significant differences were found in the volumes measured with 3D-DSA and CE-MRA as compared to TOF-MRA and CE-TOF-MRA (P < 0.01). There was a moderate significant correlation between the residual filling and the relative error of measurement in the case of TOF-MRA and CE-TOF-MRA. TOF-MRA seems to underestimate the size of aneurysm remnants detected at follow-up and should not be used as a sole imaging method to decide on re-embolization. (orig.)

  17. Hybrid Optical Unobtrusive Blood Pressure Measurements

    Directory of Open Access Journals (Sweden)

    Guangfei Zhang

    2017-07-01

    Full Text Available Blood pressure (BP is critical in diagnosing certain cardiovascular diseases such as hypertension. Some previous studies have proved that BP can be estimated by pulse transit time (PTT calculated by a pair of photoplethysmography (PPG signals at two body sites. Currently, contact PPG (cPPG and imaging PPG (iPPG are two feasible ways to obtain PPG signals. In this study, we proposed a hybrid system (called the ICPPG system employing both methods that can be implemented on a wearable device, facilitating the measurement of BP in an inconspicuous way. The feasibility of the ICPPG system was validated on a dataset with 29 subjects. It has been proved that the ICPPG system is able to estimate PTT values. Moreover, the PTT measured by the new system shows a correlation on average with BP variations for most subjects, which could facilitate a new generation of BP measurement using wearable and mobile devices.

  18. Nocturnal carbon dioxide monitoring in patients with idiopathic intracranial hypertension.

    Science.gov (United States)

    Abraham, Alon; Peled, Nir; Khlebtovsky, Alexander; Benninger, Felix; Steiner, Israel; Stiebel-Kalish, Hadas; Djaldetti, Ruth

    2013-08-01

    Idiopathic intracranial hypertension may be associated with sleep apnea. This study evaluated the incidence of sleep breathing disorders in patients with idiopathic intracranial hypertension. Overnight respiratory monitoring was performed in 22 untreated patients with idiopathic intracranial pressure diagnosed at a tertiary medical center over a two-year period and 12 sex- and age-matched control subjects. Breathing measures included heart rate, respiratory rate,oxygen saturation, and continuous end-tidal capnography. Sleep quality and daily fatigue were assessed by self-report questionnaires. Mean age of the study group was 32.6±12.2 years and of the control group, 37.0±12.9 years. Neither group had significant findings of hypoxia or hypercarbia during sleep, and there were no between-group differences in mean carbon dioxide level (patients, 35.8±4.41 mmHg; controls, 37.6±4.38 mmHg; p>0.02) or minimal oxygen saturation (96.35±1.99% and 5.69±1.71%, respectively; p>0.02). The study group had significantly more events of apnea (CO2) per hour of sleep than the control group (1.21±1.38 and 0.92±0.56, respectively; p=0.02), although values were still within normal range (<5/hr). Idiopathic intracranial hypertension is not associated with a clinically significant nocturnal breathing abnormality, and hypercarbia is apparently not involved in the pathogenesis. However, it is possible that a subtle increase in paroxysmal sleep apnea (CO2) events might be sufficient to cause vasodilatation of the cerebral blood vessels, thereby increasing intracranial pressure. Screening for sleep apnea may be appropriate in idiopathic intracranial hypertension patients, and further studies are needed to clarify this issue. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Study on 20% Piracetam for the Treatment of Patients with High Intracranial Pressure after Intracranial Tumor Surgery%20%吡拉西坦在颅内肿瘤术后颅内高压患者中应用效果观察

    Institute of Scientific and Technical Information of China (English)

    江锋; 邹武; 刘连喜; 刘超; 夏钦平; 周扬; 宾再青; 颜勇; 罗卫

    2012-01-01

    Objective: To investigate the clinical efficacy and safety of patients with high intracranial pressure after intracranial tumor surgery by piracetam. Methods: The clinical data of one hundred and thirty-six patients with high intracranial pressure after intracranial tumor surgery who were treated in the department of neurosurgery in our hospital from April 2009 to April 2012 were collected, then patients were divided into the control group and observation group randomly, patients in the control group was given 20% mannitol, but patients in the observation group was given 20% piracetam, the clinical efficacy and adverse reaction of the two groups was evaluated. Results: The total efficient rate was higher in the observation group than that in the control group (95.59%vs 85.29%, P0.05). Conclusion: 20% piracetam can obtain satisfactory curative effect for patients with high intracranial pressure after intracranial tumor surgery, and it is safe, reliable.%目的:探讨20%吡拉西坦注射液治疗颅内肿瘤术后高颅内压临床疗效和安全性.方法:选择2009年4月~2012年4月在我院神经外科住院治疗的136例颅内肿瘤术后高颅内压患者为研究对象,随机将其分为对照和实验组,对照组患者给予20%甘露醇快速静脉滴注治疗,而实验组患者则给予20%吡拉西坦快速静脉滴注治疗,比较两组患者临床疗效和不良反应发生情况.结果:实验组患者的治疗总有效率(95.59%)明显高于对照组的(85.29%),差异有显著性(P<0.05),且对照组和实验组患者在不良反应发生率方面差异无显著性(P>0.05).结论:20%吡拉西坦注射液治疗颅内肿瘤术后高颅内压临床疗效确切,降颅压疗效好,安全可靠,不良反应少.

  20. A cost effectiveness based safety and efficacy study of resterilized intra-parenchymal catheter based intracranial pressure monitoring in developing world

    Science.gov (United States)

    Gupta, Deepak Kumar; Bisht, Ajay; Batra, Priyam; Mathur, Purva; Mahapatra, Ashok Kumar

    2016-01-01

    Background: The management of traumatic brain injury (TBI) aims to maintain the normal cerebral perfusion in spite of the mass lesions that may occur (haematoma, contusion, and oedema). The monitoring of the intracranial pressure (ICP) is a step in that direction. The intra-parenchymal catheters have the lowest incidence of infection compared to intra-ventricular/subdural catheters with reliable and accurate pressure recordings. The major disadvantage of the intra-parenchymal catheters is the cost, especially in developing nations. Hypothesis: Resterilized intra-parenchymal strain gauge catheters can be used safely for ICP monitoring without any added risk of meningitis. The reusage of catheters can bring down the costs. Resterilized catheters/equipment have been approved for usage in cardiac usage, but such study on ICP catheters has not been carried out so far in any part of the world. Methodology: A total of 100 consecutive cases of severe TBI receiving ICP monitoring at a level 1 trauma center of a developing nation were prospectively studied (34 cases had fresh catheters, and 66 had resterilized [using ethylene oxide] catheters). Observations: The use of reused resterilized catheters was not associated with increased incidence of meningitis or fever (the surrogate marker for infection in this study). Also, there was concordance between the pressure recording of reused catheters and operative finding/subsequent computed tomography scans. These catheters after sterilization could be reused 2–4 times and reliably recorded the ICP (insignificant drift) with no increase in the incidence of meningitis. Conclusions: Usage of resterilized intra-parenchymal ICP catheters is feasible, safe, efficacious, and cost effective and brings down the cost of monitoring significantly. PMID:27695548

  1. The Severity of Intracranial Hemorrhages Measured by Free Hemoglobin in the Brain Depends on the Anticoagulant Class: Experimental Data

    Directory of Open Access Journals (Sweden)

    Kyle M. Ware

    2017-01-01

    Full Text Available Background and Purpose. Anticoagulant therapy is broadly used to prevent thromboembolic events. Intracranial hemorrhages are serious complications of anticoagulation, especially with warfarin. Direct oral anticoagulants reduce but do not eliminate the risk of intracranial hemorrhages. The aim of this study is to determine the degree of intracranial hemorrhage after application of anticoagulants without additional triggers. Methods. Rats were treated with different anticoagulant classes (vitamin K antagonists, heparin, direct thrombin inhibitor, and factor Xa inhibitor. Brain hemorrhages were assessed by the free hemoglobin concentration in the brain parenchyma. Results. Vitamin K antagonists (warfarin and brodifacoum significantly increased free hemoglobin in the brain. Among direct oral anticoagulants, thrombin inhibitor dabigatran also significantly increased free hemoglobin in the brain, whereas treatment with factor Xa inhibitor rivaroxaban did not have significant effect on the free hemoglobin concentration. Conclusions. Our data indicates that the severity of brain hemorrhages depends on the anticoagulant class and it is more pronounced with vitamin K antagonists.

  2. Measuring Intracranial Pressure and Correlation with Severity of Blast Traumatic Brain Injury

    Science.gov (United States)

    2013-01-01

    PLoS One, 2012. 7(4): p. e34504. 22. Ansari, M.A., K.N. Roberts, and S.W. Scheff, A time course of contusion -induced oxidative stress and synaptic...response to pulmonary blast injury. J. Trauma 40, 100S–104S. Cernak, I., Wang, Z., Jiang, J., Bian, X., and Savic, J. (2001). Ultrastructural and

  3. Intracranial pressure monitoring in severe traumatic brain injury in latin america: process and methods for a multi-center randomized controlled trial.

    Science.gov (United States)

    Carney, Nancy; Lujan, Silvia; Dikmen, Sureyya; Temkin, Nancy; Petroni, Gustavo; Pridgeon, Jim; Barber, Jason; Machamer, Joan; Cherner, Mariana; Chaddock, Kelley; Hendrix, Terence; Rondina, Carlos; Videtta, Walter; Celix, Juanita M; Chesnut, Randall

    2012-07-20

    In patients with severe traumatic brain injury (TBI), the influence on important outcomes of the use of information from intracranial pressure (ICP) monitoring to direct treatment has never been tested in a randomized controlled trial (RCT). We are conducting an RCT in six trauma centers in Latin America to test this question. We hypothesize that patients randomized to ICP monitoring will have lower mortality and better outcomes at 6-months post-trauma than patients treated without ICP monitoring. We selected three centers in Bolivia to participate in the trial, based on (1) the absence of ICP monitoring, (2) adequate patient accession and data collection during the pilot phase, (3) preliminary institutional review board approval, and (4) the presence of equipoise about the value of ICP monitoring. We conducted extensive training of site personnel, and initiated the trial on September 1, 2008. Subsequently, we included three additional centers. A total of 176 patients were entered into the trial as of August 31, 2010. Current enrollment is 81% of that expected. The trial is expected to reach its enrollment goal of 324 patients by September of 2011. We are conducting a high-quality RCT to answer a question that is important globally. In addition, we are establishing the capacity to conduct strong research in Latin America, where TBI is a serious epidemic. Finally, we are demonstrating the feasibility and utility of international collaborations that share resources and unique patient populations to conduct strong research about global public health concerns.

  4. Pseudoarachnoiditis in Spontaneous Intracranial Hypotension

    Directory of Open Access Journals (Sweden)

    Özlem Alkan

    2011-03-01

    Full Text Available Spontaneous intracranial hypotension is an important cause of new daily persistent headaches in young and middle-aged individuals. The diagnosis is made based on low cerebrospinal fluid pressure with characteristic findings upon brain and spinal magnetic resonance imaging (MRI. We present the case of a 15-year-old boy with spontaneous intracranial hypotension. Although his brain MRI was normal, his lumbar spinal MRI showed clustering of the nerve roots characteristic of arachnoiditis. Radionuclide cisternography revealed an epidural leak, which was treated with an epidural blood patch. The patient reached a near-full recovery within 24 h, and the lumbar spinal MRI findings mimicking arachnoiditis disappeared.

  5. Syphilis mimicking idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Yri, Hanne; Wegener, Marianne; Jensen, Rigmor

    2011-01-01

    or an atypical disease course should alert the physician to reevaluate a presumed IIH-diagnosis. The authors report a case of a 32-year-old non-obese male with intracranial hypertension, secondary to a syphilitic central nervous system infection, initially misdiagnosed as being idiopathic. Upon relevant......Idiopathic intracranial hypertension (IIH) is a condition of yet unknown aetiology affecting predominantly obese females of childbearing age. IIH is a diagnosis of exclusion as raised cerebrospinal fluid pressure may occur secondary to numerous other medical conditions. An atypical phenotype...

  6. Brain edema and intracranial hypertension in fulminant hepatic failure: Pathophysiology and management

    Institute of Scientific and Technical Information of China (English)

    Olivier Detry; Arnaud De Roover; Pierre Honoré; Michel Meurisse

    2006-01-01

    Intracranial hypertension is a major cause of morbidity and mortality of patients suffering from fulminant hepatic failure. The etiology of this intracranial hypertension is not fully determined, and is probably multifactorial, combining a cytotoxic brain edema due to the astrocytic accumulation of glutamine, and an increase in cerebral blood volume and cerebral blood flow, in part due to inflammation, to glutamine and to toxic products of the diseased liver. Validated methods to control intracranial hypertension in fulminant hepatic failure patients mainly include mannitol, hypertonic saline, indomethacin, thiopental, and hyperventilation.However all these measures are often not sufficient in absence of liver transplantation, the only curative treatment of intracranial hypertension in fulminant hepatic failure to date. Induced moderate hypothermia seems very promising in this setting, but has to be validated by a controlled, randomized study. Artificial liver support systems have been under investigation for many decades. The bioartificial liver, based on both detoxification and swine liver cells, has shown some efficacy on reduction of intracranial pressure but did not show survival benefit in a controlled, randomized study.The Molecular Adsorbents Recirculating System has shown some efficacy in decreasing intracranial pressure in an animal model of liver failure, but has still to be evaluated in a phase Ⅲ trial.

  7. Pyrometric fuel particle measurements in pressurized reactors

    Energy Technology Data Exchange (ETDEWEB)

    Joutsenoja, T.; Stenberg, J.; Hernberg, R.; Aho, M.; Richard, J.-R.; Mallet, C.; Bonn, B. [Tampere University of Technology, Tampere (Finland). Dept. of Physics

    1998-12-31

    A fibre-optic two-colour pyrometric technique for fuel particle temperature and size measurement is modified and applied to three pressurised reactors of different type in Finland, Germany and France. A modification of the pyrometric method for simultaneous in situ measurement of the temperature and size of individual pulverised coal particles at the pressurised entrained flow reactor of VTT Energy in Jyvaskyla was developed and several series of measurements were made in order to study the effects of oxygen concentration (3-30 vol%) and pressure (0.2-1.0 MPa) on the particle temperature. The fuels used in the experiments were Westerholt, Polish and Gottelborn hvb coals. Gardanne lignite and Niederberg anthracite. The initial nominal fuel particle size varied in the experiments from 70 to 250 {mu}m and the gas temperature was typically 1173 K. For the anthracite also the effects of gas temperature (1073-1423 K) and CO{sub 2} concentration (6-80 vol%) were studied. In Orleans a fibre-optic pyrometric device was installed to a pressurised thermogravimetric reactor of CNRS and the two-colour temperatures of fuel samples were measured. The fuel in the experiments was pulverized Gottelborn char. The reliability of optical temperature measurement in this particular application was analysed. In Essen a fibre-optic pyrometric technique that is capable to measure bed and fuel particle temperatures was applied to an atmospheric fluidised bed reactor of DMT. The effects of oxygen concentration (3-8 vol%) and bed temperature (1123-1193 K) on the fuel particle temperature were studied. The fuels in these were Westerholt coal and char and EBV-coal. 17 refs., 21 figs., 3 tabs.

  8. Incidence and risk factors of intracranial aneurysm: A national cohort study in Korea.

    Science.gov (United States)

    Kim, Tackeun; Lee, Heeyoung; Ahn, Soyeon; Kwon, O-Ki; Bang, Jae Seung; Hwang, Gyojun; Kim, Jeong Eun; Kang, Hyun-Seung; Son, Young-Je; Cho, Won-Sang; Oh, Chang Wan

    2016-10-01

    Background Estimations of the intracranial aneurysm incidence require long-term follow-up of a relatively large at-risk population; as a result, the incidence remains largely unknown. Aims To investigate the national incidence of intracranial aneurysm in a Korean population. Methods After excluding 18,604 potential subjects with a previous history of stroke (I6x.x), 998,216 subjects were included in this observational cohort. The primary endpoint was the earliest date of diagnosis of either unruptured intracranial aneurysm (UIA; I67.1) or subarachnoid hemorrhage (SAH; I60.x). We collected anthropometric data, blood pressure measurements, laboratory data, and smoking, drinking, and physical exercise habits of 132,355 subjects for whom healthcare screening data were available. Factors influencing intracranial aneurysm were evaluated via multivariate Cox regression. Results The overall observation size was 8,792,214 person-years. During follow-up, 4346 subjects were diagnosed with intracranial aneurysm (SAH, 1960; UIA, 2386). The crude incidence of intracranial aneurysm was 49.4/100,000 person-years. The hazard ratio for women was 1.56 ( p intracranial aneurysm. A history of heart disease and family history of stroke were associated with respective hazard ratios of 2.08 and 1.77. Conclusions In this Korean population study, the standardized incidence of intracranial aneurysm was 52.2/100,000 person-years. Older age, female sex, hypertension, history of heart disease, and family history of stroke were independent risk factors for intracranial aneurysm.

  9. Fluid-filled blood pressure measurement systems.

    Science.gov (United States)

    Li, J K; van Brummelen, A G; Noordergraaf, A

    1976-05-01

    The performance of catheter-manometer systems for the measurement of pulsatile pressure has been evaluated by both experimental techniques and theoretical considerations. The former approach has shown, on occasion, multiple maxima in the amplitude response. The latter has been approached in a variety of ways, ranging from extreme lumping to application of transmission line theory while employing different configurations in the system's representation. Multiple maxima have also been seen, The present paper identifies the sources of the differences found and compares the relative merits of various theoretical approaches. It introduces the compliance of the system as a figure of merit and provides a simple first-order approximation formula for evaluation of the quality of a system. Damping and impedance matching to improve the system's frequency response were studied. It was found that they were not needed in a very stiff or a very compliant system, nor should one worry about the representation of such a system.

  10. Intracranial Atherosclerotic Disease

    Directory of Open Access Journals (Sweden)

    Maria Khan

    2011-01-01

    Full Text Available Intracranial atherosclerotic disease (ICAD is the most common proximate mechanism of ischemic stroke worldwide. Approximately half of those affected are Asians. For diagnosis of ICAD, intra-arterial angiography is the gold standard to identify extent of stenosis. However, noninvasive techniques including transcranial ultrasound and MRA are now emerging as reliable modalities to exclude moderate to severe (50%–99% stenosis. Little is known about measures for primary prevention of the disease. In terms of secondary prevention of stroke due to intracranial atherosclerotic stenosis, aspirin continues to be the preferred antiplatelet agent although clopidogrel along with aspirin has shown promise in the acute phase. Among Asians, cilostazol has shown a favorable effect on symptomatic stenosis and is of benefit in terms of fewer bleeds. Moreover, aggressive risk factor management alone and in combination with dual antiplatelets been shown to be most effective in this group of patients. Interventional trials on intracranial atherosclerotic stenosis have so far only been carried out among Caucasians and have not yielded consistent results. Since the Asian population is known to be preferentially effected, focused trials need to be performed to establish treatment modalities that are most effective in this population.

  11. Simultaneous monitoring of static and dynamic intracranial pressure parameters from two separate sensors in patients with cerebral bleeds: comparison of findings

    Directory of Open Access Journals (Sweden)

    Eide Per

    2012-09-01

    Full Text Available Abstract Background We recently reported that in an experimental setting the zero pressure level of solid intracranial pressure (ICP sensors can be altered by electrostatics discharges. Changes in the zero pressure level would alter the ICP level (mean ICP; whether spontaneous changes in mean ICP happen in clinical settings is not known. This can be addressed by comparing the ICP parameters level and waveform of simultaneous ICP signals. To this end, we retrieved our recordings in patients with cerebral bleeds wherein the ICP had been recorded simultaneously from two different sensors. Materials and Methods: During a time period of 10 years, 17 patients with cerebral bleeds were monitored with two ICP sensors simultaneously; sensor 1 was always a solid sensor while Sensor 2 was a solid -, a fluid - or an air-pouch sensor. The simultaneous signals were analyzed with automatic identification of the cardiac induced ICP waves. The output was determined in consecutive 6-s time windows, both with regard to the static parameter mean ICP and the dynamic parameters (mean wave amplitude, MWA, and mean wave rise time, MWRT. Differences in mean ICP, MWA and MWRT between the two sensors were determined. Transfer functions between the sensors were determined to evaluate how sensors reproduce the ICP waveform. Results Comparing findings in two solid sensors disclosed major differences in mean ICP in 2 of 5 patients (40%, despite marginal differences in MWA, MWRT, and linear phase magnitude and phase. Qualitative assessment of trend plots of mean ICP and MWA revealed shifts and drifts of mean ICP in the clinical setting. The transfer function analysis comparing the solid sensor with either the fluid or air-pouch sensors revealed more variable transfer function magnitude and greater differences in the ICP waveform derived indices. Conclusions Simultaneous monitoring of ICP using two solid sensors may show marked differences in static ICP but close to identity

  12. Definition of Measure-theoretic Pressure Using Spanning Sets

    Institute of Scientific and Technical Information of China (English)

    Lian Fa HE; Jin Feng LV; Li Na ZHOU

    2004-01-01

    We introduce a new definition of measure-theoretic pressure for ergodic measures of continuous maps on a compact metric space. This definition is similar to those of topological pressure involving spanning sets. As an application, for C1+α(α> 0) diffeomorphisms of a compact manifold, we study the relationship between the measure-theoretic pressure and the periodic points.

  13. Effect of intracranial hypertension on cerebral hemorrhage induced autonomic nerve imbalance

    Institute of Scientific and Technical Information of China (English)

    Xuelong Jin; Wenli Jing; Fengxia Yan; Zhaoqiang Zhang; Fengjun Lü; Shuiqing Jing; Na Sun; Kazushige Mizoguchi

    2007-01-01

    respectively, then gross pathological samples were cut open, and the accuracy of hemorrhage models was affirmed. Histological sections in hemorrhage point and around this point were prepared for with hematoxylin and eosin staining, and the pathological changes were observed under light microscope.MAIN OUTCOME MEASURES: ① Changes of intracranial pressures before and after internal capsule hemorrhage and brainstem hemorrhage; ② Changes of the discharge intensity of cervical vagus nerve trunk in animal models of internal capsule hemorrhage, brainstem hemorrhage and persistent intracranial hypertension without hemorrhage; ③ Accuracy of location of internal capsule hemorrhage and brainstem hemorrhage confirmed by gross pathological samples and sections.RESULTS: Totally 65 rabbits were involved in the analysis of results. ① Dynamic state of intracranial pressure: Intracranial pressure increased obviously at 45 minutes after internal capsule hemorrhage and brainstem hemorrhage, the intracranial pressures were (1.31 ±0.30), (1.82±0.45) kPa, which were obviously higher than those before hemorrhage [(1.04±0.18), (1.05±0.19) kPa, P < 0.01]. ② Discharge of vagus nerve: Under intracranial hypertension, the discharge of cervical vagus nerve trunk was enhanced, and the discharge intensity of vagus nerve trunk was significantly different before and after persistent intracranial hypertension [(364.28±78.55), (1252.19±151.75) μ V · s, P < 0.01]. The discharges of cervical vagus nerve trunk were significantly enhanced after internal capsule hemorrhage and brainstem hemorrhage (P <0.01). ③ Validation of hemorrhage sites: The hemorrhage sites were internal capsule and brainstem on histopathological sections.CONCLUSION: Intracranial pressure may play an important role in the pathophysiological process of vagus nerve imbalance caused by cerebral hemorrhage.

  14. The clinical research on noninvasive monitoring of intracranial pressure in craniocerebral injury combined with brain CT%颅脑损伤无创颅内压监测结合头颅CT的临床研究

    Institute of Scientific and Technical Information of China (English)

    童祥龙; 黄录茂; 雍成明; 杨代明; 宣家龙; 徐兵

    2014-01-01

    目的:探讨应用闪光视觉诱发电位(FVEP)无创颅内压(ICP)监测结合头颅CT在治疗颅脑损伤患者中的应用价值。方法用ICP监测仪对80例中、重型颅脑损伤患者进行ICP监测,伤后3 d内重点监测,每次监测后行头颅CT检查并计分,分析CT演变过程,与ICP值对照。结果患者的ICP值和同期头颅CT计分比较,重型患者高于中型患者,差异有统计学意义(P<0.05)。ICP值与头颅CT计分呈显著相关(r=0.93,P<0.05)。经CT证实的21例迟发创伤性颅内血肿(DTIH),比较入院24 h ICP值,发现颅内血肿增大或一侧脑挫伤加重时,压力差也随之加大。结论 FVEP无创ICP监测结合头颅CT检查可以简单、无创、较准确反映ICP,对早期判断病情进展,指导治疗及评估预后有重要意义。%Objective To explore the treatment value of the application of flash visual evoked potential (FVEP)noninvasive in-tracranial pressure monitoring combined with head CT in patients with craniocerebral injury.Methods ICP monitoring was performed on 80 cases of patients with severe craniocerebral injury,focusing on 3 days after injury,and after each monitoring skull CT examination and scoring were made,then the CT evolution process was analysed and compared with the ICP value.Results The ICP value and the corresponding head CT score of patients with heavy injury were higher than those of medium injury patients,and the difference was statistically significant (P<0.05).ICP values were significantly correlated with CT score (r=0.93,P<0.05 head).For 21 cases of delayed traumatic intracranial he-matoma (DTIH)confirmed by CT,when 24 h ICP values were measured,it was found that with the enlargement of intracranial hematoma the increase of one side of the brain contusion,the pressure increased accordingly.Conclusion FVEP ICP noninvasive monitoring combined with the head CT examination is a simple,noninvasive method which can

  15. 呼气末正压通气对犬脑内血肿高颅压的影响%Effect of positive end-expiratory pressure on intracranial pressure in dogs with intracerebral hematoma induced intracranial hypertension

    Institute of Scientific and Technical Information of China (English)

    闫润民; 卢亦成; 于明琨; 楼美清; 张光霁; 朱诚

    2007-01-01

    目的 观察不同水平呼气末正压通气(positive end-expiratory pressure,PEEP)对犬额叶脑内血肿颅内高压的影响.方法 18只犬随机分为正常颅压组(Ⅰ组,颅内压<18 mmHg)、颅压中度增高组(Ⅱ组,颅内压25~40 mmHg)和颅压高度增高组(Ⅲ组,颅内压>40 mmHg)3组(每组各6只),全麻,气管切开插管,应用肌松剂,机械通气,右额叶脑内注入自体血制成颅内高压模型,PEEP从0开始每次增加3 cmH2O,直到18 cmH2O,每个水平持续20 min,在对侧用光纤颅内压探头监测脑内颅内压(ICP)的变化,记录平均动脉压(MAP)和中心静脉压(CVP)并计算出脑灌注压(CPP).结果 随着PEEP的递增,Ⅰ组颅内压上升,脑灌注压下降;Ⅱ、Ⅲ组颅内压略有下降,但Ⅱ组MAP、CPP上升,而Ⅲ组MAP下降,CPP下降;3组CVP都随PEEP增加而升高,但Ⅲ组上升幅度明显大于另两组(P<0.01).结论 应用PEEP通气时由于中心静脉压升高、脑静脉回流受阻和血流动力学改变,进而影响ICP和CPP.在正常颅内压状态下,PEEP使颅内压上升,在已有颅内高压存在时,PEEP对颅内压影响不明显,但在重度高颅压情况下,PEEP使CPP明显下降,提示在重度颅内高压需要应用PEEP通气时必须维持MAP,以保证足够的CPP.

  16. Evaluation of gastric pressures as an indirect method for measurement of intraabdominal pressures in the horse.

    Science.gov (United States)

    Munsterman, Amelia S; Hanson, Russell Reid

    2011-02-01

    To develop an indirect method for measurement of intraabdominal pressures in the standing horse using measurement of gastric pressures as a less invasive technique, and to compare this method with direct intraabdominal pressures obtained from the peritoneal cavity. Prospective, experimental study. University-based equine research facility. Ten healthy adult horses, 7 geldings and 3 mares. Gastric pressures were measured using a nasogastric tube with a U-tube manometry technique, while intraperitoneal pressures were measured with a peritoneal cannula. Measurements of intraabdominal pressure were obtained by both methods, simultaneously, and were evaluated using 5 increasing volumes of fluid infused into the stomach (0, 400, 1,000, 2,000, and 3,000 mL). Bias and agreement between the 2 methods were determined using Bland-Altman analysis and Lin's concordance correlation coefficients. Mean gastric pressure was 14.44 ± 4.69 cm H(2)O and ranged from 0 to 25.8 cm H(2)O. Intraperitoneal pressure measurements were generally subatmospheric, and ranged from -6.6 to 3.1 cm H(2) O (mean ± SD, -1.59 ± 2.09 cm H(2)O). Measurements of intraperitoneal pressures were repeatable; however, intra- and interindividual variance was significantly larger for measurements of gastric pressures. The mean and relative bias for comparison between the 2 techniques was 15.9 ± 5.3 cm H(2)O and 244.3 ± 199.2%, respectively. The Lin's concordance correlation coefficient between gastric and intraperitoneal pressures was -0.003 but this was not statistically significant (P=0.75). There was no statistical concordance between measurements of intraabdominal pressure using gastric and intraperitoneal pressure measurement, indicating that gastric pressures cannot be substituted for intraperitoneal pressure measurement. Direct measurement of intraperitoneal pressures may be a more consistent method for comparison of intraabdominal pressures between horses, due to less variability within and between

  17. Non-invasive estimation of intracranial pressure. MR-based evaluation in children with hydrocephalus; Nichtinvasive Bestimmung des intrakraniellen Drucks. MR-basierte Untersuchung bei Kindern mit Hydrozephalus

    Energy Technology Data Exchange (ETDEWEB)

    Muehlmann, M.; Steffinger, D.; Ertl-Wagner, B.; Koerte, I.K. [Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Muenchen (Germany); Peraud, A. [Ludwig-Maximilians-Universitaet Muenchen, Abteilung fuer Neurochirurgie, Muenchen (Germany); Lehner, M. [Dr. von Haunersches Kinderspital, Ludwig-Maximilians-Universitaet Muenchen, Abteilung fuer Kinderchirurgie, Muenchen (Germany); Heinen, F.; Alperin, N. [University Miami, Department of Radiology, Miller School of Medicine, Miami (United States)

    2012-09-15

    The intracranial pressure (ICP) is a crucially important parameter for diagnostic and therapeutic decision-making in patients with hydrocephalus. So far there is no standard method to non-invasively assess the ICP. Various approaches to obtain the ICP semi-invasively or non-invasively are discussed and the clinical application of a magnetic resonance imaging (MRI)-based method to estimate ICP (MR-ICP) is demonstrated in a group of pediatric patients with hydrocephalus. Arterial inflow, venous drainage and craniospinal cerebrospinal fluid (CSF) flow were quantified using phase-contrast imaging to derive the MR-ICP. A total of 15 patients with hydrocephalus (n=9 treated with shunt placement or ventriculostomy) underwent MRI on a 3 T scanner applying retrospectively-gated cine phase contrast sequences. Of the patients six had clinical symptoms indicating increased ICP (age 2.5-14.61 years, mean 7.4 years) and nine patients had no clinical signs of elevated ICP (age 2.1-15.9 years; mean 9.8 years; all treated with shunt or ventriculostomy). Median MR-ICP in symptomatic patients was 24.5 mmHg (25th percentile 20.4 mmHg; 75th percentile 44.6 mmHg). Median MR-ICP in patients without acute signs of increased ICP was 9.8 mmHg (25th percentile 8.6 mmHg; 75th percentile 11.4 mmHg). Group differences were significant (p < 0.001; Mann-Whitney U-test). The MR-ICP technique is a promising non-invasive tool for estimating ICP. Further studies in larger patient cohorts are warranted to investigate its application in children with hydrocephalus. (orig.) [German] Der intrakranielle Druck (''intracranial pressure'' - ICP) ist ein entscheidender Parameter bei der Diagnostik, Therapie und Verlaufsbeurteilung von Patienten mit Hydrozephalus. Derzeit gibt es keine radiologische Standardmethode, um den intrakraniellen Druck quantitativ zu bestimmen. Methoden zur invasiven und nichtinvasiven Einschaetzung des ICP werden diskutiert und die Anwendung eines MR

  18. Renal salt-wasting syndrome in children with intracranial disorders.

    Science.gov (United States)

    Bettinelli, Alberto; Longoni, Laura; Tammaro, Fabiana; Faré, Pietro B; Garzoni, Luca; Bianchetti, Mario G

    2012-05-01

    Hypotonic hyponatremia, a serious and recognized complication of any intracranial disorder, results from extra-cellular fluid volume depletion, inappropriate anti-diuresis or renal salt-wasting. The putative mechanisms by which intracranial disorders might lead to renal salt-wasting are either a disrupted neural input to the kidney or the elaboration of a circulating natriuretic factor. The key to diagnosis of renal salt-wasting lies in the assessment of extra-cellular volume status: the central venous pressure is currently considered the yardstick for measuring fluid volume status in subjects with intracranial disorders and hyponatremia. Approximately 110 cases have been reported so far in subjects ≤18 years of age (male: 63%; female: 37%): intracranial surgery, meningo-encephalitis (most frequently tuberculous) or head injury were the most common underlying disorders. Volume and sodium repletion are the goals of treatment, and this can be performed using some combination of isotonic saline, hypertonic saline, and mineralocorticoids (fludrocortisone). It is worthy of a mention, however, that some authorities contend that cerebral salt wasting syndrome does not exist, since this diagnosis requires evidence of a reduced arterial blood volume, a concept but not a measurable variable.

  19. Organic Electroluminescent Sensor for Pressure Measurement

    Directory of Open Access Journals (Sweden)

    Tomohide Niimi

    2012-10-01

    Full Text Available We have proposed a novel concept of a pressure sensor called electroluminescent pressure sensor (ELPS based on oxygen quenching of electroluminescence. The sensor was fabricated as an organic light-emitting device (OLED with phosphorescent dyes whose phosphorescence can be quenched by oxygenmolecules, and with a polymer electrode which permeates oxygen molecules. The sensor was a single-layer OLED with Platinum (II octaethylporphine (PtOEP doped into poly(vinylcarbazole (PVK as an oxygen sensitive emissive layer and poly(3,4-ethylenedioxythiophene mixed with poly(styrenesulfonate (PEDOT:PSS as an oxygen permeating polymer anode. The pressure sensitivity of the fabricated ELPS sample was equivalent to that of the sensor excited by an illumination light source. Moreover, the pressure sensitivity of the sensor is equivalent to that of conventional pressure-sensitive paint (PSP, which is an optical pressure sensor based on photoluminescence.

  20. Intracranial aneurysms.

    Science.gov (United States)

    Puskar, G; Ruggieri, P M

    1995-08-01

    MR angiography provides a rapid, accurate, and extremely flexible noninvasive evaluation of intracranial aneurysms without the cost and risk of conventional angiography. TOF and phase contrast techniques each have specific advantages and disadvantages that can be selectively exploited to optimize aneurysm evaluation. Present indications for MR angiography in aneurysm evaluation include: (1) the presence of incidental findings on a CT or MR examination that suggest the possibility of aneurysm (Figs. 7 and 8), (2) when angiography is contraindicated or when the risk is too high, (3) non-invasive follow-up of patients with known aneurysms, (4) patient refusal of contrast angiography, and (5) evaluation of patients with specific clinical symptoms (i.e., third cranial nerve palsy) or patients with non-specific subacute symptoms in whom an aneurysm might explain the clinical presentation. Although MR angiography certainly can detect aneurysms with a high rate of sensitivity and specificity, detailed decision analyses generally have not supported the overall benefit of this type of screening. Future technical advances as well as advances in the overall understanding of aneurysms may one day prove unequivocally the benefit of MR angiography in screening high-risk patient groups. MR angiography has not yet been clinically evaluated as a tool in the evaluation of acute subarachnoid hemorrhage. Potential obstacles to such an evaluation include the clinical instability of SAH patients, limited spatial resolution of the MR angiography acquisitions, the potential for subarachnoid blood or focal intraparenchymal hematomas to obscure or mimic small aneurysms, and the unreliability of MR angiography in demonstrating vasospasm. Currently these factors continue to provide an integral role for contrast angiography in aneurysm evaluation.

  1. Intracranial Hypotension Syndrome, Diagnosis and Treatment in Radiology Clinics

    Directory of Open Access Journals (Sweden)

    S. Albayram

    2005-08-01

    generalized and pulsating, and often resolve with recumbency. Other clinical features may include nausea or emesis, diplopia, neck pain, disturbance in hearing, vertigo, photophobia, and visual deficits. CSF pressures have reportedly been low, normal, or even high. CSF examination may be normal, or may reveal xanthocromia, lymphocytic pleocytosis, or increased protein possibly secondary to dural venous engorgement. With few exceptions, intracranial MR imaging of intracranial hypotension reveals diffuse pachymeningeal enhancement. Subdural fluid collections and brain descent, as measured by inferior displacement of the iter relative to the incisural line, may also be seen. Pachymeningeal enhancement is characteristically thick, smooth, and uninterrupted . The enhancement is thought to result from accumulation of gadolinium-based contrast material in engorged dural veins and in the interstitium of the dura . Mokri et al reported subdural fluid collections that were mostly bilateral and without mass effect in 69% of patients with intracranial hypotension. The authors also described imaging evidence of brain or brain-stem descent in 62% of patients in their series. Ventricular size in subjects with intracranial hypotension is usually small (1, but can reverse after treatment of the CSF leakage. In the relatively few reports in the literature of spinal imaging findings of intracranial hypotension, MR images showed extradural fluid collections and pachymeningeal enhancement (1, 4–6. MR images may also depict the site of CSF leakage in the spine (1. Herein, we described a case of intracranial hypotension with symmetric bulky epidural enhancement seen along the anterolateral borders of the cervical spine. This enhancement was compatible with engorged epidural venous structures based on their characteristic location in the anterolateral spinal canal and sparing of the midline. Renowden et al (6 described a single case of intracranial hypotension with epidural venous engorgement in

  2. Intramuscular Pressure Measurement During Locomotion in Humans

    Science.gov (United States)

    Ballard, Ricard E.

    1996-01-01

    To assess the usefulness of intramuscular pressure (IMP) measurement for studying muscle function during gait, IMP was recorded in the soleus and tibialis anterior muscles of ten volunteers during, treadmill walking, and running using transducer-tipped catheters. Soleus IMP exhibited single peaks during late-stance phase of walking (181 +/- 69 mmHg, mean +/- S.E.) and running (269 +/- 95 mmHg). Tibialis anterior IMP showed a biphasic response, with the largest peak (90 +/- 15 mmHg during walking and 151 +/- 25 mmHg during running) occurring shortly after heel strike. IMP magnitude increased with gait speed in both muscles. Linear regression of soleus IMP against ankle joint torque obtained by a dynamometer in two subjects produced linear relationships (r = 0.97). Application of these relationships to IMP data yielded estimated peak soleus moment contributions of 0.95-165 Nm/Kg during walking, and 1.43-2.70 Nm/Kg during running. IMP results from local muscle tissue deformations caused by muscle force development and thus, provides a direct, practical index of muscle function during locomotion in humans.

  3. Normative Values of Retinal Oxygen Saturation in Rhesus Monkeys: The Beijing Intracranial and Intraocular Pressure (iCOP Study.

    Directory of Open Access Journals (Sweden)

    Jing Li

    Full Text Available To study the normal values of the retinal oxygen saturation in Rhesus monkeys and to evaluated repeatability and reproducibility of retinal oxygen saturation measurements.Eighteen adult Rhesus macaque monkeys were included in this experimental study. An Oxymap T1 retinal oximeter (Oxymap, Reykjavik, Iceland was used to perform oximetry on all subjects. Global arterial (SaO2 and venous oxygen saturation (SvO2, arteriovenous difference in SO2 were measured. In the first examination, each eye was imaged three times. At the following two examinations, each eye was imaged once. All examinations were finished in one month. P values were calculated to evaluate the difference between the measurements during three visits by performing an ANOVA. Intra-visit and inter-visit intraclass correlation coefficient (ICC was determined.At baseline, the average SaO2 and SvO2 were 89.48 ± 2.64% and 54.85 ± 2.18%, respectively. The global A-V difference was 34.63 ± 1.91%. The difference between the three visits was not significant (p>0.05. The highest A-V difference in SO2 and lowest saturations were found in the inferotemporal quadrant. Intra-session and inter-visit repeatability were both high. For all oxygen saturation parameters, the ICC values of the intra-session repeatability ranged between 0.92 and 0.96. As found previously, a relatively high ICC value for inter-visit repeatability also was found for all oxygen saturation measurements, ranging between 0.86 and 0.94, with the lowest values in the infero-nasal quadrant.Our study is the first to describe retinal SO2 in healthy Rhesus monkeys. In normal monkey eyes, the reproducibility and repeatability of retinal oximetry oxygen saturation measurements were high in the retinal arterioles and venules. Our results support that Oxymap T1 retinal oximetry is a suitable and reliable technique in monkey studies.

  4. Intracranial artery velocity measurement using 4D PC MRI at 3 T: comparison with transcranial ultrasound techniques and 2D PC MRI

    Energy Technology Data Exchange (ETDEWEB)

    Meckel, Stephan [University Hospital Freiburg, Department of Neuroradiology, Freiburg (Germany); Leitner, Lorenz; Schubert, Tilman [University Hospital Basel, Institute of Radiology, Basel (Switzerland); Bonati, Leo H.; Lyrer, Philippe [University Hospital Basel, Department of Neurology, Basel (Switzerland); Santini, Francesco [University Hospital Basel, Department of Radiological Physics, Institute of Radiology, Basel (Switzerland); Stalder, Aurelien F. [Xuanwu Hospital - Capital Medical University, Department of Radiology, Beijing (China); Markl, Michael [Northwestern University Feinberg School of Medicine, Departments of Radiology and Biomedical Engineering, Chicago (United States); Wetzel, Stephan G. [Neuroradiology, Swiss Neuro Institute, Klinik Hirslanden, Zurich (Switzerland)

    2013-04-15

    4D phase contrast MR imaging (4D PC MRI) has been introduced for spatiotemporal evaluation of intracranial hemodynamics in various cerebrovascular diseases. However, it still lacks validation with standards of reference. Our goal was to compare blood flow quantification derived from 4D PC MRI with transcranial ultrasound and 2D PC MRI. Velocity measurements within large intracranial arteries [internal carotid artery (ICA), basilar artery (BA), and middle cerebral artery (MCA)] were obtained in 20 young healthy volunteers with 4D and 2D PC MRI, transcranial Doppler sonography (TCD), and transcranial color-coded duplex sonography (TCCD). Maximum velocities at peak systole (PSV) and end diastole (EDV) were compared using regression analysis and Bland-Altman plots. Correlation of 4D PC MRI measured velocities was higher in comparison with TCD (r = 0.49-0.66) than with TCCD (0.35-0.44) and 2D PC MRI (0.52-0.60). In mid-BA and ICA C7 segment, a significant correlation was found with TCD (0.68-0.81 and 0.65-0.71, respectively). No significant correlation was found in carotid siphon. On average over all volunteers, PSVs and EDVs in MCA were minimally underestimated compared with TCD/TCCD. Minimal overestimation of velocities was found compared to TCD in mid-BA and ICA C7 segment. 4D PC MRI appears as valid alternative for intracranial velocity measurement consistent with previous reference standards, foremost with TCD. Spatiotemporal averaging effects might contribute to vessel size-dependent mild underestimation of velocities in smaller (MCA), and overestimation in larger-sized (BA and ICA) arteries, respectively. Complete spatiotemporal flow analysis may be advantageous in anatomically complex regions (e.g. carotid siphon) relative to restrictions of ultrasound techniques. (orig.)

  5. Intraglottal velocity and pressure measurements in a hemilarynx model.

    Science.gov (United States)

    Oren, Liran; Gutmark, Ephraim; Khosla, Sid

    2015-02-01

    Determining the mechanisms of self-sustained oscillation of the vocal folds requires characterization of the pressures produced by intraglottal aerodynamics. Because most of the intraglottal aerodynamic forces cannot be measured in a tissue model of the larynx, current understanding of vocal fold vibration mechanism is derived from mechanical, analytical, and computational models. Previous studies have computed intraglottal pressures from measured intraglottal velocity fields and intraglottal geometry; however, this technique for determining pressures is not yet validated. In this study, intraglottal pressure measurements taken in a hemilarynx model are compared with pressure values that are computed from simultaneous velocity measurements. The results showed that significant negative pressure formed near the superior aspect of the folds during closing, which agrees with previous measurements in other hemilarynx models. Intraglottal velocity measurements show that the flow near the superior aspect separates from the glottal wall during closing and may develop into a vortex, which further augments the magnitude of negative pressure. Intraglottal pressure distributions, computed by solving the pressure Poisson equation, showed good agreement with pressure measurements. The match between the pressure computations and its measurements validates the current technique, which was previously used to estimate intraglottal pressure distribution in a full larynx model.

  6. Retention curves measured using pressure plate and pressure membrane apparatus

    DEFF Research Database (Denmark)

    Hansen, Morten Hjorslev

    This report presents a proposal for a test method for the measurement of the retention curve, especially in the high moisture content range, and the pore size distribution of building materials. The test method includes the measurement of apparent density, solid density, and open porosity. The re...

  7. Mannitol-induced rebleeding from intracranial aneurysm. Case report

    DEFF Research Database (Denmark)

    Rosenørn, J; Westergaard, L; Hansen, P H

    1983-01-01

    A case is presented in which rebleeding from an intracranial saccular aneurysm occurred a few minutes after intravenous administration of mannitol during surgery. The relationship between the reducing effect of mannitol on elevated intracranial pressure and the increased pressure gradient across...

  8. Mannitol-induced rebleeding from intracranial aneurysm. Case report

    DEFF Research Database (Denmark)

    Rosenørn, J; Westergaard, L; Hansen, P H

    1983-01-01

    A case is presented in which rebleeding from an intracranial saccular aneurysm occurred a few minutes after intravenous administration of mannitol during surgery. The relationship between the reducing effect of mannitol on elevated intracranial pressure and the increased pressure gradient across...... the aneurysm wall, causing risk of rebleeding, is discussed. Procedures that can reduce this risk are summarized....

  9. Turbulent pressure fluctuations measured during CHATS

    Science.gov (United States)

    Steven P. Oncley; William J. Massman; Edward G. Patton

    2008-01-01

    Fast-response pressure fluctuations were included in the Canopy Horizontal Array of Turbulence Study (CHATS) at several heights within and just above the canopy in a walnut orchard. Two independent systems were intercompared and then separated. We present an evaluation of turbulence statistics - including the pressure transport term in the turbulence kinetic energy...

  10. [An integrated system of blood pressure measurement with bluetooth communication].

    Science.gov (United States)

    Wang, Wei; Wang, Jing; Sun, Hongyang; Xu, Zuyang; Chai, Xinyu

    2012-07-01

    The development of the integrated blood pressure system with bluetooth communication function is introduced. Experimental results show that the system can complete blood pressure measurement and data transmission wireless effectively, which can be used in m-Health in future.

  11. Auscultatory versus oscillometric measurement of blood pressure in octogenarians

    DEFF Research Database (Denmark)

    Rosholm, Jens-Ulrik; Pedersen, Sidsel Arnspang; Matzen, Lars;

    2012-01-01

    Auscultatory measurement using a sphygmomanometer has been the predominant method for clinical estimation of blood pressure, but it is now rapidly being replaced by oscillometric measurement.......Auscultatory measurement using a sphygmomanometer has been the predominant method for clinical estimation of blood pressure, but it is now rapidly being replaced by oscillometric measurement....

  12. Indirect blood pressure measurement: a need to reassess.

    Science.gov (United States)

    Anderson, F D; Cunningham, S G; Maloney, J P

    1993-07-01

    Indirect blood pressure measurement is the assessment tool used most frequently in epidemiological studies and hypertension management in the population at large. To review indirect blood pressure measurement within the context of nursing practice. Nurses are not following recommended American Heart Association measurement guidelines. A national program of certification in indirect blood pressure measurement, similar to that of basic and advanced cardiac life support, is needed. An initial approach to evaluating present practice is also suggested.

  13. Correcting for response lag in unsteady pressure measurements in water

    Energy Technology Data Exchange (ETDEWEB)

    Conger, R.N. [John Graham Associates, Seattle, WA (United States); Ramaprian, B.R. [Washington State Univ., Pullman, WA (United States). Dept. of Mechanical and Materials Engineering

    1993-12-01

    There is not much information available on the use of diaphragm-type pressure transducers for the measurements of unsteady pressures in liquids. A procedure for measuring the dynamic response of a pressure transducer in such applications and correcting for its inadequate response is discussed in this report. An example of the successful use of this method to determine unsteady surface pressures on a pitching airfoil in a water channel is presented.

  14. Noninvasive Measurement of Central Vascular Pressures With Arterial Tonometry: Clinical Revival of the Pulse Pressure Waveform?

    Science.gov (United States)

    Nelson, Matthew R.; Stepanek, Jan; Cevette, Michael; Covalciuc, Michael; Hurst, R. Todd; Tajik, A. Jamil

    2010-01-01

    The arterial pulse has historically been an essential source of information in the clinical assessment of health. With current sphygmomanometric and oscillometric devices, only the peak and trough of the peripheral arterial pulse waveform are clinically used. Several limitations exist with peripheral blood pressure. First, central aortic pressure is a better predictor of cardiovascular outcome than peripheral pressure. Second, peripherally obtained blood pressure does not accurately reflect central pressure because of pressure amplification. Lastly, antihypertensive medications have differing effects on central pressures despite similar reductions in brachial blood pressure. Applanation tonometry can overcome the limitations of peripheral pressure by determining the shape of the aortic waveform from the radial artery. Waveform analysis not only indicates central systolic and diastolic pressure but also determines the influence of pulse wave reflection on the central pressure waveform. It can serve as a useful adjunct to brachial blood pressure measurements in initiating and monitoring hypertensive treatment, in observing the hemodynamic effects of atherosclerotic risk factors, and in predicting cardiovascular outcomes and events. Radial artery applanation tonometry is a noninvasive, reproducible, and affordable technology that can be used in conjunction with peripherally obtained blood pressure to guide patient management. Keywords for the PubMed search were applanation tonometry, radial artery, central pressure, cardiovascular risk, blood pressure, and arterial pulse. Articles published from January 1, 1995, to July 1, 2009, were included in the review if they measured central pressure using radial artery applanation tonometry. PMID:20435839

  15. Blood pressure and anthropometric measurements in healthy ...

    African Journals Online (AJOL)

    Institute of Child Health, University of Benin Teaching Hospital, Benin City, Nigeria ... Blood pressures were higher in private school pupils compared with public school pupils of the ... or risks of screening and treating such underlying causes of.

  16. [Prolonged hypothermia in refractory intracranial hypertension. Report of one case].

    Science.gov (United States)

    Rovegno, Maximiliano; Valenzuela, José Luis; Mellado, Patricio; Andresen, Max

    2012-02-01

    The use of hypothermia after cardiac arrest caused by ventricular fibrillation is a standard clinical practice, however its use for neuroprotection has been extended to other conditions. We report a 23-year-old male with intracranial hypertension secondary to a parenchymal hematoma associated to acute hydrocephalus. An arterial malformation was found and embolized. Due to persistent intracranial hypertension, moderate hypothermia with a target temperature of 33°C was started. After 12 hours of hypothermia, intracranial pressure was controlled. After 13 days of hypothermia a definitive control of intracranial pressure was achieved. The patient was discharged 40 days after admission, remains with a mild hemiparesia and is reassuming his university studies.

  17. [Measurement of blood pressure variability and the clinical value].

    Science.gov (United States)

    Kékes, Ede; Kiss, István

    2014-10-19

    Authors have collected and analyzed literature data on blood pressure variability. They present the methods of blood pressure variability measurement, clinical value and relationships with target organ damages and risk of presence of cardiovascular events. They collect data about the prognostic value of blood pressure variability and the effects of different antihypertensive drugs on blood pressure variability. They underline that in addition to reduction of blood pressure to target value, it is essential to influence blood pressure fluctuation and decrease blood pressure variability, because blood pressure fluctuation presents a major threat for the hypertensive subjects. Data from national studies are also presented. They welcome that measurement of blood pressure variability has been included in international guidelines.

  18. Ionic conductivity measurements of zirconia under pressure using impedance spectroscopy

    CERN Document Server

    Takebe, H; Ohtaka, O; Fukui, H; Yoshiasa, A; Yamanaka, T; Ota, K; Kikegawa, T

    2002-01-01

    We have set up an electrical conductivity measurement system under high-pressure and high-temperature conditions with a multi-anvil high-pressure apparatus using an AC complex impedance method. With this system, we have successfully measured the electrical conductivity of stabilized ZrO sub 2 (Y sub 2 O sub 3 -ZrO sub 2 solid solution) under pressures up to 5 GPa in the temperature range from 300 to 1200 K. The electrical conductivities obtained under pressure are compatible with those of previous results measured at ambient pressure.

  19. Intracranial Hematoma

    Science.gov (United States)

    ... skull, most commonly caused by rupture of a blood vessel within the brain or from trauma such as a car accident or fall. The ... in the brain. There are many causes, including trauma, rupture of an aneurysm, vascular malformation, high blood pressure and tumor. There are ...

  20. Measurement of unsteady surface pressure on rotor blades of fans by pressure-sensitive paint

    Science.gov (United States)

    Yokoyama, Hiroshi; Miura, Kouhei; Iida, Akiyoshi

    2017-01-01

    To clarify the unsteady pressure distributions on the rotor blades of an axial fan, a pressure-sensitive paint (PSP) technique was used. To capture the image of the rotating fan as a static image, an optical derotator method with a dove prism was adopted. It was confirmed by preliminary experiments with a resonator and a speaker that the pressure fluctuations with 347 Hz can be measured by the present PSP. The measured mean pressure distributions were compared with the predicted results based on large-eddy simulations. The measured instantaneous surface pressure is instrumental to identify acoustic source of fan noise in the design stage.

  1. Measurement of improved pressure dependence of superconducting transition temperature

    Science.gov (United States)

    Karmakar, S.

    2013-06-01

    We describe a technique for making electrical transport measurements in a diamond anvil cell at liquid helium temperature having in situ pressure measurement option, permitting accurate pressure determination at any low temperature during the resistance measurement scan. In general, for four-probe resistivity measurements on a polycrystalline sample, four fine gold wires are kept in contact with the sample with the help of the compression from the soft solid (usually alkali halides such as NaCl, KCl, etc.) acting as a pressure-transmitting medium. The actual pressure on the sample is underestimated if not measured from a ruby sphere placed adjacent to the sample and at that very low temperature. Here, we demonstrate the technique with a quasi-four-probe resistance measurement on an Fe-based superconductor in the temperature range 1.2-300 K and pressures up to 8 GPa to find an improved pressure dependence of the superconducting transition temperature.

  2. [Reproducibility of arterial pressure measured in the ELSA-Brasil with 24-hour pressure monitoring].

    Science.gov (United States)

    Nascimento, Larissa Rangel; Molina, Maria del Carmen Bisi; Faria, Carolina Perim; Cunha, Roberto de Sá; Mill, José Geraldo

    2013-06-01

    To determine the reproducibility of casual arterial pressure measurement and to confirm pressure diagnosis by monitoring of participants in the ELSA-Brasil (Estudo Longitudinal de Saúde do Adulto - Brazilian Longitudinal Study for Adult Health). Casual blood pressure was measured with an oscilometric device. A sub-sample of participants (N = 255) from Espírito Santo state (Southeastern Brazil) was reevaluated using the same methodology following one to ten weeks and, in addition, underwent arterial blood pressure monitoring. Diagnosis of hypertension used cut off points of 140/90 mmHg for casual pressure and 130/80 mmHg for arterial blood pressure monitoring. White coat hypertension was defined as the presence of hypertension in casual blood pressure and normal arterial blood pressure monitoring, and converse findings characterized masked hypertension. Data are from 230 participants that on the two occasions were free from antihypertensive medication (N1 = 153) or under the same antihypertensive regimen (N2 = 77). Normotension was confirmed by arterial blood pressure monitoring in 120 out of 134 participants of the N1 group. In N2, blood pressure control was confirmed by arterial blood pressure monitoring in 43 of 54 participants with controlled hypertension per casual blood pressure. Overall diagnostic concordance between casual blood pressure and arterial blood pressure monitoring was 78% (kappa = 0.44). In the N1 group, six subjects (4%) presented white coat hypertension, and 23 subjects (25%) presented with masked hypertension. Diagnostic concordance between casual blood pressure and arterial blood pressure monitoring was moderate. The rigorous standardization of casual blood pressure measurement adopted in the ELSA-Brasil study was able to reduce white coat hypertension. The high frequency of masked hypertension may suggest that pressure values obtained by arterial blood pressure monitoring indicate an elevated degree of stress at work.

  3. 甘露醇与吡拉西坦注射液治疗颅内肿瘤术后高颅内压的疗效观察%Clinical Observation of Mannitol and Piracetam Injection for Postoperative High Intracranial Pressure in Intracranial Tumor

    Institute of Scientific and Technical Information of China (English)

    田强; 郭启; 赵梅星; 苑玉存; 朱明华

    2014-01-01

    Objective To study the efficacy and safety of mannitol and piracetam injection for postoperative high in -tracranial pressure in intracranial tumor .Methods 76 cases of intracranial tumor patients with high intracranial pressure in ac-cordance with admission time were divided into the control group and the observation group ,each with 38 cases.The control group received 20%mannitol infusion,and the observation group were treated with 20% piracetam injection.Clinical efficacy,adverse reactions ,and the signs and symptoms of increased intracranial pressure before and after treatment of the 2 groups were recorded . Results The onset time,peak time,duration,intracranial pressure reduction of the observation group were respectively (0.47 ± 0.21) h,(1 ±0.42) h,(4.31 ±1.41) h,(10.81 ±4.41) mmHg,and those of the control group were (0.48 ±0.23) h,(0.98 ±0.45) h,(4.35 ±1.37) h,(10.69 ±4.47) mmHg (P>0.05).The effective rates of the observation group and the control group were 94.74%(36/38) and 92.11%(35/38) (P>0.05);there had no obvious adverse reactions in both groups ,and blood test ,electrolytes and liver and kidney function before and after treatment had no abnormality .Conclusion Compared with mannitol,piracetam injection for postoperative high intracranial pressure in intracranial tumor has similar curative effect ,and ei-ther treatments has no obvious adverse reactions .The onset time and other indicators of the 2 treatments has no significant differ-ence,so the clinical treatment of postoperative high intracranial pressure in intracranial tumor patients should be decided accord -ing to the actual situation of patients .%目的:探讨甘露醇与吡拉西坦注射液治疗颅内肿瘤术后高颅内压的疗效及安全性。方法将76例颅内肿瘤术后高颅内压患者按照住院时间先后顺序分为对照组与观察组,各38例。对照组采用20%甘露醇快速静脉滴注,观察组采用20%吡拉西坦注射液治疗。统计2组患者

  4. Phase-Contrast MRI measurements in intra-cranial aneurysms in-vivo of flow patterns, velocity fields and wall shear stress: A comparison with CFD

    Science.gov (United States)

    Boussel, Loic; Rayz, Vitaliy; Martin, Alastair; Acevedo-Bolton, Gabriel; Lawton, Michael T.; Higashida, Randall; Smith, Wade S.; Young, William L.; Saloner, David

    2010-01-01

    Evolution of intracranial aneurysms is known to be related to hemodynamic forces such as Wall Shear Stress (WSS) and Maximum Shear Stress (MSS). Estimation of these parameters can be performed using numerical simulations (computational fluid dynamics - CFD) but can also be directly measured with MRI using a time-dependent 3D phase-contrast sequence with encoding of each of the three components of the velocity vectors (7D-MRV). In order to study the accuracy of 7D-MRV in estimating these parameters in–vivo, in comparison with CFD, 7D-MRV and patient-specific CFD modeling was performed for three patients who had intracranial aneurysms. A visual and a quantitative analysis of the flow pattern and the distribution of velocities, MSS, and WSS were performed between the two techniques. Spearman's coefficients of correlation between the two techniques were 0.56 for the velocity field, 0.48 for MSS and 0.59 for WSS. Visual analysis and Bland-Altman plots showed a good agreement for flow pattern and velocities but large discrepancies for MSS and WSS. In conclusion, these results indicate that in-vivo 7D-MRV can be used to measure velocity flow fields and to estimate MSS and WSS but is not currently able to provide accurate quantification of these two last parameters. PMID:19161132

  5. Acoustic sensor for remote measuring of pressure

    Directory of Open Access Journals (Sweden)

    Kataev V. F.

    2008-04-01

    Full Text Available The paper deals with sensors based on delay lines on surface acoustic waves (SAW, having a receiving-emitting and a reflective interdigital transducers (IDT. The dependence of the reflection coefficient of SAW on type and intensity of the load was studied. The authors propose a composite delay line in which the phase of the reflection coefficient depends on the pressure. Pressure leads to a shift of the reflective IDT relative to the transceiver, because they are located on different substrates. The paper also presents functional diagrams of the interrogator.

  6. Intraparenchymal intracranial pressure monitoring in patients with acute liver failure Monitoreo intraparenquimatoso de presión intracraneana en pacientes con falla hepática aguda

    Directory of Open Access Journals (Sweden)

    Alejandra T. Rabadán

    2008-06-01

    Full Text Available BACKGROUND: Elevated intracranial pressure (ICP is a common cause of death in acute liver failure (ALF and is determinant for decision-making regarding the timing of liver transplantation. The recommended type ICP monitoring device is controversial in ALF patients. Epidural devices had less risk of hemorrhagic complications, but they are less reliable than intraparenchymal ones. METHOD: Twenty-three patients with ALF were treated, and 19 of them received a liver transplant. Seventeen patients had ICP monitoring because of grade III-IV encephalopathy. All patients received fresh plasma (2-3 units before and during placing the intraparenchymal device. RESULTS: Eleven cases (64.7% had elevated ICP, and 6 patients (35.2% had normal values. One patient (5.9% had an asymptomatic small intraparenchymal haemorrhage ANTECEDENTES: La presión intracraneana elevada (PIC es una causa frecuente de muerte en la falla hepática aguda (FHA y es determinante para la toma de decisiones respecto del momento del transplante hepático. El tipo de dispositivo para el monitoreo de OIC es controversial em los pacientes em FHA. Los dispositivos epidurales tienen menos riesgo de complicaciones hemorrágicas, pero son menos confiables que los intraparenquimatosos. MÉTODO: Veintitrés pacientes con FHA fueron tratados, y 19 de ellos recibieron un transplante hepático. diecisiete pacientes tuvieron monitoreo de PIC debido a encefalopatía grado III-IV. Todos los pacientes recibieron plasma fresco (2-3 unidades antes y durante la colocación de la fibra intraparenquimatosa. RESULTADOS: Once casos (64.7% tuvieron PIC elevada, y 6 pacientes (35.2% tuvieron valores normales. Un paciente (5.9% tuvo una pequeña hemorragia intraparenquimatosa asintomática <1cm³ en TAC, la cual no impidió el transplante hepático. CONCLUSIÓN: En nuestra experiencia, el monitoreo intraparenquimatoso de presión intracraneana en pacientes con FHA parece ser un método preciso y con bajo riesgo

  7. Regional cooling for reducing brain temperature and intracranial pressure Resfriamento cerebral regional para redução da temperatura e pressão intracraniana

    Directory of Open Access Journals (Sweden)

    Luis Vicente Forte

    2009-06-01

    Full Text Available OBJECTIVE: To evaluate the effectiveness of regional cooling for reducing brain temperature (BrTe and intracranial pressure (ICP in patients where conventional clinical treatment has failed. METHOD: Regional cooling was carried out using ice bags covering the area of the craniectomy (regional method in 23 patients. The BrTe and ICP were determined using a fiber optic sensor. Thirteen patients (56.52% were female. The ages ranged from 16 to 83 years (mean of 48.9. The mean APACHE II score was 25 points (11-35. The patients were submitted, on mean, to 61.7 hours (20-96 of regional cooling. RESULTS: There was a significant reduction in mean BrTe (pOBJETIVO: Avaliar a eficácia do resfriamento regional na redução da temperatura cerebral (TeCe e pressão intracraniana (PIC após falha das medidas clínicas convencionais de tratamento. MÉTODO: O resfriamento cerebral foi realizado com bolsas com gelo, colocadas sobre a área de craniectomia (método regional em 23 doentes. A TeCe e PIC foram verificadas com sensor de fibra óptica. Treze (56,52% eram do sexo feminino. A idade variou de 16 a 83 anos (média 48,96. A pontuação média no índice APACHE II foi 25 pontos (11-35. Os doentes foram submetidos, em média, a 61,7 horas (20-96 de resfriamento regional. RESULTADOS: Houve uma redução significativa da TeCe média (p<0,0001-de 37,1ºC para 35,2ºC e da PIC média (p=0,0001-de 28 mmHg para 13 mmHg. CONCLUSÃO: Nossos resultados sugerem que o resfriamento regional foi eficaz no controle da PIC nos doentes submetidos, previamente, a craniectomia descompressiva.

  8. Physiologically-relevant measurements of flow through coils and stents: towards improved modeling of endovascular treatment of intracranial aneurysms

    Science.gov (United States)

    Barbour, Michael; Levitt, Michael; Geindreau, Christian; Rolland Du Roscoat, Sabine; Johnson, Luke; Chivukula, Keshav; Aliseda, Alberto

    2016-11-01

    The hemodynamic environment in cerebral aneurysms undergoing flow-diverting stent (FDS) or coil embolization treatment plays a critical role in long-term outcomes. Standard modeling approaches to endovascular coils and FDS simplify the complex geometry into a homogenous porous volume or surface through the addition of a Darcy-Brinkman pressure loss term in the momentum equation. The inertial and viscous loss coefficients are typically derived from published in vitro studies of pressure loss across FDS and coils placed in a straight tube, where the only fluid path is across the treatment - an unrealistic representation of treatment apposition in vivo. The pressure drop across FDS and coils in side branch aneurysms located on curved parent vessels is measured. Using PIV, the velocity at the aneurysm neck plane is reconstructed and used to determine loss coefficients for better models of endovascular coils or FDS that account for physiological placement and vessel curvature. These improved models are incorporated into CFD simulations and validated against in vitro model PIV velocity, as well as compared to microCT-based coil/stent-resolving CFD simulations of patient-specific treated aneurysm flow.

  9. Compressibility measurements of gases using externally heated pressure vessels.

    Science.gov (United States)

    Presnall, D. C.

    1971-01-01

    Most of the data collected under conditions of high temperature and pressure have been determined using a thick-walled bomb of carefully measured and fixed volume which is externally heated by an electric furnace or a thermostatically controlled bath. There are numerous variations on the basic method depending on the pressure-temperature range of interest, and the particular gas or gas mixture being studied. The construction and calibration of the apparatus is discussed, giving attention to the pressure vessel, the volume of the bomb, the measurement of pressure, the control and measurement of temperature, and the measurement of the amount and composition of gas in the bomb.

  10. Pressure and Magnetics Measurements of Single and Merged Jets

    Science.gov (United States)

    Messer, S.; Case, A.; Brockington, S.; Bomgardner, R.; Witherspoon, F. D.

    2010-11-01

    We present pressure and magnetic data from both a single full scale coaxial gun and from the merging of jets from several minirailguns. The magnetic probes measure all three components of field, and include an array of probes inside the coaxial gun. Magnetic measurements beyond the muzzle of the gun show the scale of currents trapped in the plasma plume. The pressure probe measures adiabatic stagnation pressure and shows how this quantity decreases with distance from the gun as well as the changes in stagnation pressure through the merge process. Stagnation pressure is influenced by density, temperature, and velocity, and serves as a check on spectroscopic and interferometer measurements. Unlike optical measurements, stagnation pressure is taken at a definite location. These guns are early prototypes of guns to be installed on the Plasma Liner eXperiment at LANL. The jet-merging results are reviewed in the context of what is expected for PLX.

  11. Validation of an Endoscopic Fibre-Optic Pressure Sensor for Noninvasive Measurement of Variceal Pressure

    Directory of Open Access Journals (Sweden)

    Bin Sun

    2016-01-01

    Full Text Available In this study, the authors have developed endoscopic fibre-optic pressure sensor to detect variceal pressure and presented the validation of in vivo and in vitro studies, because the HVPG requires catheterization of hepatic veins, which is invasive and inconvenient. Compared with HVPG, it is better to measure directly the variceal pressure without puncturing the varices in a noninvasive way.

  12. Reliability of blood pressure measurement and cardiovascular risk prediction

    OpenAIRE

    van der Hoeven, N.V.

    2016-01-01

    High blood pressure is one of the leading risk factors for cardiovascular disease, but difficult to reliably assess because there are many factors which can influence blood pressure including stress, exercise or illness. The first part of this thesis focuses on possible ways to improve the reliability of blood pressure measurement for proper cardiovascular risk prediction, both in and out of the doctor’s office. We show that it is possible to obtain a reliable blood pressure without the use o...

  13. A method enabling simultaneous pressure and temperature measurement using a single piezoresistive MEMS pressure sensor

    Science.gov (United States)

    Frantlović, Miloš; Jokić, Ivana; Lazić, Žarko; Smiljanić, Milče; Obradov, Marko; Vukelić, Branko; Jakšić, Zoran; Stanković, Srđan

    2016-12-01

    In this paper we present a high-performance, simple and low-cost method for simultaneous measurement of pressure and temperature using a single piezoresistive MEMS pressure sensor. The proposed measurement method utilizes the parasitic temperature sensitivity of the sensing element for both pressure measurement correction and temperature measurement. A parametric mathematical model of the sensor was established and its parameters were calculated using the obtained characterization data. Based on the model, a real-time sensor correction for both pressure and temperature measurements was implemented in a target measurement system. The proposed method was verified experimentally on a group of typical industrial-grade piezoresistive sensors. The obtained results indicate that the method enables the pressure measurement performance to exceed that of typical digital industrial pressure transmitters, achieving at the same time the temperature measurement performance comparable to industrial-grade platinum resistance temperature sensors. The presented work is directly applicable in industrial instrumentation, where it can add temperature measurement capability to the existing pressure measurement instruments, requiring little or no additional hardware, and without adverse effects on pressure measurement performance.

  14. Hindlimb Suspension (HLS) in Rodents for the Study of Intracranial Pressure, Molecular and Histologic Changes in the Eye, and CSF Production Regulation and Resorption: A Status Report of Two Studies

    Science.gov (United States)

    Theriot, C. A.; Taibbi, G.; Vizzeri, G.; Parsons-Wingerter, P.; Chevez-Barrios, P.; Rivera, A.; Zanello, S. B.

    2016-01-01

    This status report corresponds to two studies tied to an animal experiment being executed at the University of California Davis (Charles Fuller's laboratory). The animal protocol uses the well-documented rat hindlimb suspension (HLS) model, to examine the relationship between cephalic fluid shifts and the regulation of intracranial (ICP) and intraocular (IOP) pressures as well as visual system structure and function. Long Evans rats are subjected to HLS durations of 7, 14, 28 and 90 days. Subgroups of the 90-day animals are studied for recovery periods of 7, 14, 28 or 90 days. All HLS subjects have age-matched cage controls. Various animal cohorts are planned for this study: young males, young females and old males. In addition to the live measures (ICP by telemetry, IOP and retinal parameters by optical coherence tomography) which are shared with the Fuller study, the specific outcomes for this study include: -Gene expression analysis of the retina -Histologic analysis - Analysis of the microvasculature of retina flat mounts by NASA's VESsel GENeration Analysis (VESGEN) Software. To date, the young male and female cohorts are being completed. Due to the need to keep technical variation to a minimum, the histologic and genomic analyses have been delayed until all samples from each cohort are available and can be processed in a single batch per cohort. The samples received so far correspond to young males sacrificed at 7,14, 28 and 90 days of HLS and at 90 days of recovery; and from young females sacrificed at 7, 14 and 28 of HLS. A complementary study titled: "A gene expression and histologic approach to the study of cerebrospinal fluid (CSF) production and outflow in hindlimb suspended rats" seeks to study the molecular components of CSF production and outflow modulation as a result of HLS, bringing a molecular and histologic approach to investigate genome wide expression changes in the arachnoid villi and choroid plexus of HLS rats compared to rats in normal

  15. Design and Development of a Pressure Transducer for High Hydrostatic Pressure Measurements up to 200 MPa

    Science.gov (United States)

    Kumar, Anuj; Yadav, Sanjay; Agarwal, Ravinder

    2016-06-01

    A number of pressure transducers, based on strain gauge, capacitance/inductance type, frequency resonators, are commercially available and are being used for sensing and producing an electrical output proportional to applied pressure. These sensors have their own advantages and limitations due to operational ease, measurement uncertainty and the costs. Strain gauge type transducers are now well established devices for accurate and precise measurement of pressure within measurement uncertainty up to 0.1 % of full scale. In the present research work, an indigenous strain gauge pressure transducer has been designed, developed, tested and calibrated for pressure measurement up to 200 MPa. The measurement uncertainty estimated using the pressure transducer was found better than 0.1 % of full scale. This transducer was developed using four foil type strain gauges, bonded, two in axial direction while other two in radial direction, to the controlled stress zones of a tubular maraging steel active cylinder working also as diaphragm. The strain gages were then connected to a Wheatstone bridge arrangement to measure stress generated strains. The pressure was applied through matching connector designed in the same tubular transducer active element. The threaded unique design in a single piece through collar, ferule and tubing arrangement provides leak proof pressure connections with external devices without using additional seals. The calibration and performance checking of the pressure transducer was carried out using dead weight type national pressure standard using the internationally accepted calibration procedure.

  16. Design and Development of a Pressure Transducer for High Hydrostatic Pressure Measurements up to 200 MPa

    Science.gov (United States)

    Kumar, Anuj; Yadav, Sanjay; Agarwal, Ravinder

    2017-08-01

    A number of pressure transducers, based on strain gauge, capacitance/inductance type, frequency resonators, are commercially available and are being used for sensing and producing an electrical output proportional to applied pressure. These sensors have their own advantages and limitations due to operational ease, measurement uncertainty and the costs. Strain gauge type transducers are now well established devices for accurate and precise measurement of pressure within measurement uncertainty up to 0.1 % of full scale. In the present research work, an indigenous strain gauge pressure transducer has been designed, developed, tested and calibrated for pressure measurement up to 200 MPa. The measurement uncertainty estimated using the pressure transducer was found better than 0.1 % of full scale. This transducer was developed using four foil type strain gauges, bonded, two in axial direction while other two in radial direction, to the controlled stress zones of a tubular maraging steel active cylinder working also as diaphragm. The strain gages were then connected to a Wheatstone bridge arrangement to measure stress generated strains. The pressure was applied through matching connector designed in the same tubular transducer active element. The threaded unique design in a single piece through collar, ferule and tubing arrangement provides leak proof pressure connections with external devices without using additional seals. The calibration and performance checking of the pressure transducer was carried out using dead weight type national pressure standard using the internationally accepted calibration procedure.

  17. Rapid natural resolution of intracranial hematoma

    Institute of Scientific and Technical Information of China (English)

    吴明灿; 刘建雄; 罗国才; 张志文; 闵杰; 余辉; 姚远

    2004-01-01

    Objective:To investigate the clinical characteristics of intracranial hematoma and the mechanism involved in its rapid natural resolution. Methods:Seventeen cases of intracranial hematoma with typical clinical and CT manifestations were retrospectively studied. Results: Intracranial hematoma was found obviously decreased in size within 72 h after its occurrence in 8 cases. The rest 9 cases presented complete resolution. Conclusions: Rapid natural resolution of acute epidural hematoma is mostly found in teenagers and the resolution is correlated with cranial fracture at the hematoma site. As for acute subdural hematoma, its rapid resolution is associated with the transfer of cerebrospinal fluid toward subdural space, the lavage effect, and the compression caused by the increased intracranial pressure or the space left resulting from redistribution of the hematoma in brain atrophy.

  18. A blood pressure measurement method based on synergetics theory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>The principle for blood pressure measurement using pulse transit time is introduced in this paper.And the math model of synergetics theory is studied in detail.The synergetics theory is applied in the analysis of blood pressure measurement data.The simulation results show that the application of synergetics theory is helpful to judge the normal blood pressure,and the accuracy is up to 80%.

  19. Intracranial hypertension without headache in children.

    Science.gov (United States)

    Aylward, Shawn C; Aronowitz, Catherine; Reem, Rachel; Rogers, David; Roach, E Steve

    2015-05-01

    We aimed to determine the frequency of intracranial hypertension without headache in children. We retrospectively analyzed patients evaluated in a pediatric intracranial hypertension referral center. Patients were divided into 2 groups depending on whether they complained of headache at the time of presentation. Age, body mass index, and opening cerebrospinal fluid pressures were considered continuous variables and compared by Wilcoxon rank-sum test because of non-normality. A P value of .05 was considered significant. A total of 228 charts were reviewed; 152 patients met the criteria for intracranial hypertension and 22/152 patients (14.5%) met the criteria of optic nerve edema without headache. There were clinically significant differences in age and body mass index between the 2 groups. The group without headache was typically younger and not obese. The opening pressure and modified opening pressure were not clinically significant between the 2 groups. © The Author(s) 2014.

  20. Modern gas-based temperature and pressure measurements

    CERN Document Server

    Pavese, Franco

    2013-01-01

    This 2nd edition volume of Modern Gas-Based Temperature and Pressure Measurements follows the first publication in 1992. It collects a much larger set of information, reference data, and bibliography in temperature and pressure metrology of gaseous substances, including the physical-chemical issues related to gaseous substances. The book provides solutions to practical applications where gases are used in different thermodynamic conditions. Modern Gas-Based Temperature and Pressure Measurements, 2nd edition is the only comprehensive survey of methods for pressure measurement in gaseous media used in the medium-to-low pressure range closely connected with thermometry. It assembles current information on thermometry and manometry that involve the use of gaseous substances which are likely to be valid methods for the future. As such, it is an important resource for the researcher. This edition is updated through the very latest scientific and technical developments of gas-based temperature and pressure measurem...

  1. Nontraumatic intracranial hemorrhage.

    Science.gov (United States)

    Fischbein, Nancy J; Wijman, Christine A C

    2010-11-01

    Nontraumatic (or spontaneous) intracranial hemorrhage most commonly involves the brain parenchyma and subarachnoid space. This entity accounts for at least 10% of strokes and is a leading cause of death and disability in adults. Important causes of spontaneous intracranial hemorrhage include hypertension, cerebral amyloid angiopathy, aneurysms, vascular malformations, and hemorrhagic infarcts (both venous and arterial). Imaging findings in common and less common causes of spontaneous intracranial hemorrhage are reviewed.

  2. Blood pressure self-measurement in the obstetric waiting room

    DEFF Research Database (Denmark)

    Wagner, Stefan; Kamper, Christina H.; Toftegaard, Thomas Skjødeberg

    2013-01-01

    a reliable blood pressure reading. Results: We found that the patients did not adhere to given instructions when performing blood pressure self-measurement in the waiting room. None of the 81 patients adhered to all six inves- tigated recommendations, while around a quarter adhered to five out of six......Background: Pregnant diabetic patients are often required to self- measure their blood pressure in the waiting room before consulta- tion. Currently used blood pressure devices do not guarantee valid measurements when used unsupervised. This could lead to misdi- agnosis and treatment error. The aim...... of this study was to investigate current use of blood pressure self-measurement in the waiting room in order to identify challenges that could influence the resulting data quality. Also, we wanted to investigate the potential for addressing these challenges with e-health and telemedicine technology. Subjects...

  3. Idiopathic intracranial hypertension, hormones, and 11β-hydroxysteroid dehydrogenases

    DEFF Research Database (Denmark)

    Markey, Keira A; Uldall, Maria; Botfield, Hannah;

    2016-01-01

    Idiopathic intracranial hypertension (IIH) results in raised intracranial pressure (ICP) leading to papilledema, visual dysfunction, and headaches. Obese females of reproductive age are predominantly affected, but the underlying pathological mechanisms behind IIH remain unknown. This review...... such as adipokines, steroid hormones, and ICP regulation may be key to the understanding and future management of IIH....

  4. High pressure differential conductance measurements of (Pb,Sn)Se

    Science.gov (United States)

    Paul, Tiffany; Vangennep, Derrick; Jackson, Daniel; Biswas, Amlan; Hamlin, James

    Topological transitions have been recognized as a new type of quantum phase transition. Recently, a number of papers have reported scanning tunneling microscope (STM) measurements of the Landau level spectra of topologically non-trivial materials. Such measurements can offer substantial insight into the nature of the transition between topologically distinct phases. Although applied pressure represents an attractive means to drive a topological quantum phase transition, STM measurements can not be performed under high pressure conditions. In this talk, I will discuss our recent attempts to observe Landau level spectra in compressed (Pb,Sn)Se using differential conductance measurements. Acknowledgements: TAP supported by REU NSF DMR-1461019. Pressure cell development and measurements at high magnetic fields supported by the National High Magnetic Field Laboratory User Collaboration Grants Program. Synthesis, characterization, and high pressure measurements supported by NSF DMR-1453752.

  5. Combined NMR moisture, temperature and pressure measurements during heating

    Directory of Open Access Journals (Sweden)

    Pel L.

    2013-09-01

    Full Text Available For model validation, quantitative measurements of the evolution of moisture, temperature, and pressure distributions in time are needed. For this purpose, we have developed an NMR setup to measure the moisture transport in heated building materials. The measured combined moisture content and temperature profiles give a unique insight in the moisture transport and dehydration kinetics inside concrete during fire. These measurements give the first quantitative proof for the build-up of a moisture peak due to the vapor pressure build-up. In this study we have also combined for the first time the measurement of the moisture and temperature profiles with the measurement of the pressure at one position, which show that the pressure build up is directly related to the moisture profiles.

  6. Prevention and Treatment of Shivering after Intracranial Surgery Using Different Dosages of Tramadol

    Institute of Scientific and Technical Information of China (English)

    Yu-hua Qi; Guo-nian Wang; Shu-yan Wang

    2005-01-01

    @@ During the anesthesia recovery period, shivering is a common uncomfortable complaint of patients increasing oxygen consumption, carbon dioxide production, intraocular and intracranial pressures, all disadvantage for intracranial tumor surgery. The aim of our study is to observe the effect of different dosages of tramadol in the prevention and treatment of shivering after intracranial surgery.

  7. Brain tissue pressure measurements in perinatal and adult rabbits.

    Science.gov (United States)

    Hornig, G W; Lorenzo, A V; Zavala, L M; Welch, K

    1987-12-01

    Brain tissue pressure (BTP) in pre- and post-natal anesthetized rabbits, held in a stereotactic head holder, was measured with a fluid filled 23 gauge open-ended cannula connected distally to a pressure transducer. By advancing the cannula step wise through a hole in the cranium it was possible to sequentially measure pressure from the cranial subarachnoid space, cortex, ventricle and basal ganglia. Separate cannulas and transducers were used to measure CSFP from the cisterna magna and arterial and/or venous pressure. Pressure recordings obtained when the tip of the BTP cannula was located in the cranial subarachnoid space or ventricle exhibited respiratory and blood pressure pulsations equivalent to and in phase with CSF pulsations recorded from the cisterna magna. When the tip was advanced into brain parenchymal sites such pulsations were suppressed or non-detectable unless communication with a CSF compartment had been established inadvertently. Although CSF pressures in the three spinal fluid compartments were equivalent, in most animals BTP was higher than CSFP. However, after momentary venting of the system BTP equilibrated at a pressure below that of CSFP. We speculate that venting of the low compliance system (1.20 x 10(-5) ml/mmHg) relieves the isometric pressure build-up due to insertion of the cannula into brain parenchyma. Under these conditions, and at all ages examined, BTP in the rabbit is consistently lower than CSFP and, as with CSFP, it increases as the animal matures.

  8. TREATMENT OF HYPERTENSION USING TELEMEDICAL HOME BLOOD PRESSURE MEASUREMENTS

    DEFF Research Database (Denmark)

    Hoffmann-Petersen, N; Lauritzen, T; Bech, J N

    2015-01-01

    of the measurements and subsequent communication by telephone or E-mail. In the control group, patients received usual care. Primary outcome was reduction in daytime ambulatory blood pressure measurements (ABPM) from baseline to 3 months' follow-up. RESULTS: In both groups, daytime ABPM decreased significantly....../181), p = 0.34. Blood pressure reduction in the TBPM group varied with the different practices. CONCLUSIONS: No further reduction in ABPM or number of patients reaching blood pressure targets was observed when electronic transmission of TBPM was applied in the treatment of hypertension by GPs. Thus......OBJECTIVE: Telemonitoring of home blood pressure measurements (TBPM) is a new and promising supplement to diagnosis, control and treatment of hypertension. We wanted to compare the outcome of antihypertensive treatment based on TBPM and conventional monitoring of blood pressure. DESIGN AND METHOD...

  9. Pico gauges for minimally invasive intracellular hydrostatic pressure measurements

    DEFF Research Database (Denmark)

    Knoblauch, Jan; Mullendore, Daniel L.; Jensen, Kaare Hartvig

    2014-01-01

    in the tip of microcapillaries, which we call pico gauges. The production of pico gauges can be accomplished with standard laboratory equipment, and measurements are comparably easy to conduct. Example pressure measurements are performed on cells that are difficult or impossible to measure with other methods.......Intracellular pressure has a multitude of functions in cells surrounded by a cell wall or similar matrix in all kingdoms of life. The functions include cell growth, nastic movements, and penetration of tissue by parasites. The precise measurement of intracellular pressure in the majority of cells......, however, remains difficult or impossible due to their small size and/or sensitivity to manipulation. Here, we report on a method that allows precise measurements in basically any cell type over all ranges of pressure. It is based on the compression of nanoliter and picoliter volumes of oil entrapped...

  10. Pico gauges for minimally invasive intracellular hydrostatic pressure measurements.

    Science.gov (United States)

    Knoblauch, Jan; Mullendore, Daniel L; Jensen, Kaare H; Knoblauch, Michael

    2014-11-01

    Intracellular pressure has a multitude of functions in cells surrounded by a cell wall or similar matrix in all kingdoms of life. The functions include cell growth, nastic movements, and penetration of tissue by parasites. The precise measurement of intracellular pressure in the majority of cells, however, remains difficult or impossible due to their small size and/or sensitivity to manipulation. Here, we report on a method that allows precise measurements in basically any cell type over all ranges of pressure. It is based on the compression of nanoliter and picoliter volumes of oil entrapped in the tip of microcapillaries, which we call pico gauges. The production of pico gauges can be accomplished with standard laboratory equipment, and measurements are comparably easy to conduct. Example pressure measurements are performed on cells that are difficult or impossible to measure with other methods.

  11. Noninvasive microbubble-based pressure measurements: a simulation study

    NARCIS (Netherlands)

    Postema, Michiel; Bouakaz, Ayache; Jong, de Nico

    2004-01-01

    This paper describes a noninvasive method to measure local hydrostatic pressures in fluid filled cavities. The method is based on the disappearance time of a gas bubble, as the disappearance time is related to the hydrostatic pressure. When a bubble shrinks, its response to ultrasound changes. From

  12. Perilymphatic pressure measurement in patients with Meniere's disease

    NARCIS (Netherlands)

    Mateijsen, DJM; Rosingh, HJ; Wit, HP; Albers, FWJ

    2001-01-01

    The MMS-10 Tympanic Displacement Analyser is a new device for measuring perilymphatic pressure in humans. This instrument was used in 70 patients with Meniere's disease (44 affected ears) and a group of 50 young normal hearing subjects. No significant differences in perilymphatic pressure measuremen

  13. Definition-consistent measurement of exchange market pressure

    NARCIS (Netherlands)

    Klaassen, F.; Jager, H.

    2011-01-01

    Currencies can be under severe pressure, but in a managed exchange rate regime that is not fully visible via the change in the exchange rate. The literature has proposed a way to measure such exchange market pressure (EMP) indirectly, by adding interest rate changes and forex interventions to the

  14. Definition-consistent measurement of exchange market pressure

    NARCIS (Netherlands)

    Klaassen, F.; Jager, H.

    2011-01-01

    Currencies can be under severe pressure, but in a managed exchange rate regime that is not fully visible via the change in the exchange rate. The literature has proposed a way to measure such exchange market pressure (EMP) indirectly, by adding interest rate changes and forex interventions to the ex

  15. Perilymphatic pressure measurement in patients with Meniere's disease

    NARCIS (Netherlands)

    Mateijsen, DJM; Rosingh, HJ; Wit, HP; Albers, FWJ

    The MMS-10 Tympanic Displacement Analyser is a new device for measuring perilymphatic pressure in humans. This instrument was used in 70 patients with Meniere's disease (44 affected ears) and a group of 50 young normal hearing subjects. No significant differences in perilymphatic pressure

  16. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  17. NOISY INTRACRANIAL TUMORS

    NARCIS (Netherlands)

    VANDOOREN, BTH; VANBRUGGEN, AC; MOOIJ, JJA; HEW, JM; JOURNEE, HL

    1994-01-01

    Transorbital sound recordings were obtained from 21 patients with intracranial tumours, 28 patients with intracranial aneurysms and 20 control patients. The group of patients with tumours consisted of 12 patients with gliomas, of whom 6 had low-grade gliomas and 6 had high-grade gliomas, and 9 patie

  18. Unruptured intracranial aneurysms

    NARCIS (Netherlands)

    Backes, Daan

    2016-01-01

    Rupture of an intracranial aneurysm results in aneurysmal subarachnoid hemorrhage (SAH), a subtype of stroke with an incidence of 9 per 100,000 person-years and a case-fatality around 35%. In order to prevent SAH, patients with unruptured intracranial aneurysms can be treated by neurosurgical or end

  19. Paediatric intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    A A Wani

    2006-01-01

    Full Text Available Intracranial aneurysms in childhood account for 1-2% of intracranial aneurysms.[1],[2] These aneurysms have unique characteristics that make them different from those in adults. These differences are evident in their epidemiology, location, clinical spectrum, association with trauma and infection, complications and outcome.

  20. Automatic noninvasive measurement of systolic blood pressure using photoplethysmography

    Directory of Open Access Journals (Sweden)

    Glik Zehava

    2009-10-01

    Full Text Available Abstract Background Automatic measurement of arterial blood pressure is important, but the available commercial automatic blood pressure meters, mostly based on oscillometry, are of low accuracy. Methods In this study, we present a cuff-based technique for automatic measurement of systolic blood pressure, based on photoplethysmographic signals measured simultaneously in fingers of both hands. After inflating the pressure cuff to a level above systolic blood pressure in a relatively slow rate, it is slowly deflated. The cuff pressure for which the photoplethysmographic signal reappeared during the deflation of the pressure-cuff was taken as the systolic blood pressure. The algorithm for the detection of the photoplethysmographic signal involves: (1 determination of the time-segments in which the photoplethysmographic signal distal to the cuff is expected to appear, utilizing the photoplethysmographic signal in the free hand, and (2 discrimination between random fluctuations and photoplethysmographic pattern. The detected pulses in the time-segments were identified as photoplethysmographic pulses if they met two criteria, based on the pulse waveform and on the correlation between the signal in each segment and the signal in the two neighboring segments. Results Comparison of the photoplethysmographic-based automatic technique to sphygmomanometry, the reference standard, shows that the standard deviation of their differences was 3.7 mmHg. For subjects with systolic blood pressure above 130 mmHg the standard deviation was even lower, 2.9 mmHg. These values are much lower than the 8 mmHg value imposed by AAMI standard for automatic blood pressure meters. Conclusion The photoplethysmographic-based technique for automatic measurement of systolic blood pressure, and the algorithm which was presented in this study, seems to be accurate.

  1. Dynamic surface pressure measurements on a square cylinder with pressure sensitive paint

    Energy Technology Data Exchange (ETDEWEB)

    McGraw, C.M.; Khalil, G.; Callis, J.B. [University of Washington, Department of Chemistry, Seattle, WA (United States); Bell, J.H. [Ames Research Center, National Aeronautics and Space Administration, Moffett Field, CA (United States)

    2006-02-01

    The dynamic and static surface pressure on a square cylinder during vortex shedding was measured with pressure sensitive paints (PSPs) at three angles of incidence and a Reynolds number of 8.9 x 10{sup 4}. Oscillations in the phosphorescence intensity of the PSP that occurred at the vortex shedding frequency were observed. From these phosphorescent oscillations, the time-dependent changes in pressure distribution were calculated. This work extends PSP's useful range to dynamic systems where oscillating pressure changes are on the order of 230 Pa and occur at frequencies in the range of 95-125 Hz. (orig.)

  2. Transport measurements under pressure in III-IV layered semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Segura, A.; Errandonea, D.; Martinez-Garcia, D. [ICMUV, Universitat de Valencia, Ed. Investigacio, 46100 Burjassot (Spain); Manjon, F.J. [Dpto. de Fisica Aplicada, Univ. Politecnica de Valencia, Cno. de Vera s/n, 46022 Valencia (Spain); Chevy, A. [Physique des Milieux Condenses, Universite Pierre et Marie Curie, 75252 Paris Cedex 05 (France); Tobias, G.; Ordejon, P.; Canadell, E. [Institut de Ciencia dels Materials de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra (Barcelona) (Spain)

    2007-01-15

    This paper reports on Hall effect, resistivity and thermopower effect measurements under high pressure up to 12 GPa in p-type {gamma}-indium selenide (InSe) and {epsilon}-gallium selenide (GaSe). The paper focuses on two applications of transport measurements under pressure: electronic structure and phase transition studies. As concerns the electronic structure, we investigate the origin of the striking differences between the pressure behaviour of transport parameters in both layered compounds. While the hole concentration and mobility increase moderately and monotonously in {epsilon}-GaSe up to 10 GPa, a large increase of the hole concentration at near 0.8 GPa and a large continuous increase of the hole mobility, which doubled its ambient pressure value by 3.2 GPa, is observed in {gamma}-InSe. Based on electronic structure calculations the difference is found to arise from the pressure evolution of the valence band maximum. While the shape of the valence band maximum is virtually pressure-insensitive in {epsilon}-GaSe, it changes dramatically in {gamma}-InSe, with the emergence of a ring-shaped subsidiary maximum that becomes the absolute valence-band maximum as pressure increases. Transport measurements as a function of pressure and temperature are also used to investigate the phase diagram of InSe and, in particular, the transition to the rock-salt polymorph. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Reversible Cerebral Vasoconstriction Syndrome with Intracranial Hypertension: Should Decompressive Craniectomy Be Considered?

    Science.gov (United States)

    Mrozek, Ségolène; Lonjaret, Laurent; Jaffre, Aude; Januel, Anne-Christine; Raposo, Nicolas; Boetto, Sergio; Albucher, Jean-François; Fourcade, Olivier; Geeraerts, Thomas

    2017-01-01

    Background Reversible cerebral vasoconstriction syndrome (RCVS) is a rare cause of intracerebral hemorrhage (ICH) causing intracranial hypertension. Methods Case report. Results We report a case of RCVS-related ICH leading to refractory intracranial hypertension. A decompressive craniectomy was performed to control intracranial pressure. We discuss here the management of RCVS with intracranial hypertension. Decompressive craniectomy was preformed to avoid the risky option of high cerebral perfusion pressure management with the risk of bleeding, hemorrhagic complications, and high doses of norepinephrine. Neurological outcome was good. Conclusion RCVS has a complex pathophysiology and can be very difficult to manage in cases of intracranial hypertension. Decompressive craniectomy should probably be considered.

  4. Method and Apparatus for Measuring Surface Air Pressure

    Science.gov (United States)

    Lin, Bing (Inventor); Hu, Yongxiang (Inventor)

    2014-01-01

    The present invention is directed to an apparatus and method for remotely measuring surface air pressure. In one embodiment, the method of the present invention utilizes the steps of transmitting a signal having multiple frequencies into the atmosphere, measuring the transmitted/reflected signal to determine the relative received power level of each frequency and then determining the surface air pressure based upon the attenuation of the transmitted frequencies.

  5. Quantitative analysis of sensor for pressure waveform measurement

    Directory of Open Access Journals (Sweden)

    Tyan Chu-Chang

    2010-01-01

    Full Text Available Abstract Background Arterial pressure waveforms contain important diagnostic and physiological information since their contour depends on a healthy cardiovascular system 1. A sensor was placed at the measured artery and some contact pressure was used to measure the pressure waveform. However, where is the location of the sensor just about enough to detect a complete pressure waveform for the diagnosis? How much contact pressure is needed over the pulse point? These two problems still remain unresolved. Method In this study, we propose a quantitative analysis to evaluate the pressure waveform for locating the position and applying the appropriate force between the sensor and the radial artery. The two-axis mechanism and the modified sensor have been designed to estimate the radial arterial width and detect the contact pressure. The template matching method was used to analyze the pressure waveform. In the X-axis scan, we found that the arterial diameter changed waveform (ADCW and the pressure waveform would change from small to large and then back to small again when the sensor was moved across the radial artery. In the Z-axis scan, we also found that the ADCW and the pressure waveform would change from small to large and then back to small again when the applied contact pressure continuously increased. Results In the X-axis scan, the template correlation coefficients of the left and right boundaries of the radial arterial width were 0.987 ± 0.016 and 0.978 ± 0.028, respectively. In the Z-axis scan, when the excessive contact pressure was more than 100 mm Hg, the template correlation was below 0.983. In applying force, when using the maximum amplitude as the criteria level, the lower contact pressure (r = 0.988 ± 0.004 was better than the higher contact pressure (r = 0.976 ± 0.012. Conclusions Although, the optimal detective position has to be close to the middle of the radial arterial, the pressure waveform also has a good completeness with

  6. Compression-tracking photoacoustic perfusion and microvascular pressure measurements

    Science.gov (United States)

    Choi, Min; Zemp, Roger

    2017-03-01

    We propose a method to measure blood pressure of small vessels non-invasively and in-vivo: by combining PA imaging with compression US. Using this method, we have shown pressure-lumen area tracking, as well as estimation of the internal vessel pressure, located 2 mm deep in tissue. Additionally, reperfusion can be tracked by measuring the total PA signal within a region of interest (ROI) after compression has been released. The ROI is updated using cross-correlation based displacement tracking1. The change in subcutaneous perfusion rates can be seen when the temperature of the hand of a human subject drops below the normal.

  7. A note on measurement of sound pressure with intensity probes

    DEFF Research Database (Denmark)

    Juhl, Peter; Jacobsen, Finn

    2004-01-01

    be improved under a variety of realistic sound field conditions by applying a different weighting of the two pressure signals from the probe. The improved intensity probe can measure the sound pressure more accurately at high frequencies than an ordinary sound intensity probe or an ordinary sound level meter......The effect of scattering and diffraction on measurement of sound pressure with "two-microphone" sound intensity probes is examined using an axisymmetric boundary element model of the probe. Whereas it has been shown a few years ago that the sound intensity estimated with a two-microphone probe...

  8. Refractory Intracranial Hypertension due to Fentanyl Administration Following Closed Head Injury

    Directory of Open Access Journals (Sweden)

    Sara E Hocker

    2013-01-01

    Full Text Available BackgroundAlthough the effects of opioids on intracranial pressure have long been a subject of controversy, they are frequently administered to patients with severe head trauma. We present a patient with an uncommon paradoxical response to opioids.Case ReportA patient with refractory intracranial hypertension after closed head injury was managed with standard medical therapy with only transient decreases in the intracranial pressure. Only after discontinuation of opiates did the intracranial pressure become manageable without metabolic suppression and rescue osmotic therapy, implicating opiates as the etiology of refractory intracranial hypertension in this patient. ConclusionsClinicians should consider opioids as a contributing factor in malignant intracranial hypertension when findings on neuroimaging do not explain persistent and refractory intracranial hypertension.

  9. In-shoe plantar pressure measurement and analysis system based on fabric pressure sensing array.

    Science.gov (United States)

    Shu, Lin; Hua, Tao; Wang, Yangyong; Qiao Li, Qiao; Feng, David Dagan; Tao, Xiaoming

    2010-05-01

    Spatial and temporal plantar pressure distributions are important and useful measures in footwear evaluation, athletic training, clinical gait analysis, and pathology foot diagnosis. However, present plantar pressure measurement and analysis systems are more or less uncomfortable to wear and expensive. This paper presents an in-shoe plantar pressure measurement and analysis system based on a textile fabric sensor array, which is soft, light, and has a high-pressure sensitivity and a long service life. The sensors are connected with a soft polymeric board through conductive yarns and integrated into an insole. A stable data acquisition system interfaces with the insole, wirelessly transmits the acquired data to remote receiver through Bluetooth path. Three configuration modes are incorporated to gain connection with desktop, laptop, or smart phone, which can be configured to comfortably work in research laboratories, clinics, sport ground, and other outdoor environments. A real-time display and analysis software is presented to calculate parameters such as mean pressure, peak pressure, center of pressure (COP), and shift speed of COP. Experimental results show that this system has stable performance in both static and dynamic measurements.

  10. Measuring the local pressure amplitude in microchannel acoustophoresis

    DEFF Research Database (Denmark)

    Barnkob, Rune; Augustsson, Per; Laurell, Thomas

    2010-01-01

    A new method is reported on how to measure the local pressure amplitude and the Q factor of ultrasound resonances in microfluidic chips designed for acoustophoresis of particle suspensions. The method relies on tracking individual polystyrene tracer microbeads in straight water-filled silicon...... of the microbeads. From the curve fits we obtain the acoustic energy density, and hence the pressure amplitude as well as the acoustophoretic force. By plotting the obtained energy densities as a function of applied frequency, we obtain Lorentzian line shapes, from which the resonance frequency and the Q factor...... for each resonance peak are derived. Typical measurements yield acoustic energy densities of the order of 10 J/m3, pressure amplitudes of 0.2 MPa, and Q factors around 500. The observed half wavelength of the transverse acoustic pressure wave is equal within 2% to the measured width w = 377 m...

  11. Validation of NIS 500 MPa hydraulic pressure measurement

    Directory of Open Access Journals (Sweden)

    Eltawil Alaaeldin A.

    2017-01-01

    Full Text Available 500 MPa pressure is considered as the common maximum pressure in most of the National Metrology Institutes worldwide; however, validation of the uncertainty in that range required a lot of work. NIS when recognized on, 2008 guaranteed big uncertainty value above 200 MPa due to the absence of international comparison at that time. This paper summarizes the results of a validation of 500 MPa range of hydraulic gauge pressure measurements carried out at NIS. The study covers the calibration through direct comparison and through using of a pressure sensor. The paper summarized the technical work carried out at the results of measurements and the effect of these results on NIS Calibration Measurements Capability. The validation also includes the comparison between the obtained results and pervious calibration of the same piston-cylinder assembly that calibrated against the NIST primary standard.

  12. MEASUREMENT OF FRICTIONAL PRESSURE DIFFERENTIALS DURING A VENTILATION SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    B.S. Prosser, PE; I.M. Loomis, PE, PhD

    2003-11-03

    During the course of a ventilation survey, both airflow quantity and frictional pressure losses are measured and quantified. The measurement of airflow has been extensively studied as the vast majority of ventilation standards/regulations are tied to airflow quantity or velocity. However, during the conduct of a ventilation survey, measurement of airflow only represents half of the necessary parameters required to directly calculate the airway resistance. The measurement of frictional pressure loss is an often misunderstood and misapplied part of the ventilation survey. This paper compares the two basic methods of frictional pressure drop measurements; the barometer and the gauge and tube. Personal experiences with each method will be detailed along with the authors' opinions regarding the applicability and conditions favoring each method.

  13. Can a Pressure Standard be Based on Capacitance Measurements?

    Science.gov (United States)

    Moldover, Michael R

    1998-01-01

    We consider the feasibility of basing a pressure standard on measurements of the dielectric constant ϵ and the thermodynamic temperature T of helium near 0 °C. The pressure p of the helium would be calculated from fundamental constants, quantum mechanics, and statistical mechanics. At present, the relative standard uncertainty of the pressure ur(p) would exceed 20 × 10(-6), the relative uncertainty of the value of the molar polarizability of helium Aϵ calculated ab initio. If the relativistic corrections to Aϵ were calculated as accurately as the classical value is now known, a capacitance-based pressure standard might attain ur(p) < 6 × 10(-6) for pressures near 1 MPa, a result of considerable interest for pressure metrology. One obtains p by eliminating the density from the virial expansions for p and ϵ - 1. If ϵ - 1 were measured with a very stable, 0.5 pF toroidal cross capacitor, the small capacitance and the small values of ϵ - 1 would require state-of-the-art capacitance measurements to achieve a useful pressure standard.

  14. Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

    Directory of Open Access Journals (Sweden)

    A. R. Rodi

    2012-11-01

    Full Text Available A method is described that estimates the error in the static pressure measurement on an aircraft from differential pressure measurements on the hemispherical surface of a Rosemount model 858AJ air velocity probe mounted on a boom ahead of the aircraft. The theoretical predictions for how the pressure should vary over the surface of the hemisphere, involving an unknown sensitivity parameter, leads to a set of equations that can be solved for the unknowns – angle of attack, angle of sideslip, dynamic pressure and the error in static pressure – if the sensitivity factor can be determined. The sensitivity factor was determined on the University of Wyoming King Air research aircraft by comparisons with the error measured with a carefully designed sonde towed on connecting tubing behind the aircraft – a trailing cone – and the result was shown to have a precision of about ±10 Pa over a wide range of conditions, including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, geometric altitude data from a combined Global Navigation Satellite System (GNSS and inertial measurement unit (IMU system are used to estimate acceleration effects on the error, and the algorithm is shown to predict corrections to a precision of better than ±20 Pa under those conditions. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are discussed.

  15. Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

    Directory of Open Access Journals (Sweden)

    A. R. Rodi

    2012-05-01

    Full Text Available Geometric altitude data from a combined Global Navigation Satellite System (GNSS and inertial measurement unit (IMU system on the University of Wyoming King Air research aircraft are used to estimate acceleration effects on static pressure measurement. Using data collected during periods of accelerated flight, comparison of measured pressure with that derived from GNSS/IMU geometric altitude show that errors exceeding 150 Pa can occur which is significant in airspeed and atmospheric air motion determination. A method is developed to predict static pressure errors from analysis of differential pressure measurements from a Rosemount model 858 differential pressure air velocity probe. The method was evaluated with a carefully designed probe towed on connecting tubing behind the aircraft – a "trailing cone" – in steady flight, and shown to have a precision of about ±10 Pa over a wide range of conditions including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, compared to the GNSS/IMU data, this algorithm predicts corrections to a precision of better than ±20 Pa. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are examined.

  16. The "Skull Flap" a new conceived device for decompressive craniectomy experimental study on dogs to evaluate the safety and efficacy in reducing intracranial pressure and subsequent impact on brain perfusion

    Directory of Open Access Journals (Sweden)

    Chibbaro Salvatore

    2013-01-01

    Full Text Available Background: Decompressive craniectomy (DC is a procedure performed increasingly often in current neurosurgical practice. Significant perioperative morbidity may be associated to this procedure because of the large skull defect; also, later closure of the skull defect (cranioplasty may be associated to post-operative morbidity as much as any other reconstructive operation. The authors present a newly conceived/developed device: The "Skull Flap" (SF. This system, placed at the time of the craniectomy, offers the possibility to provide cranial reconstruction sparing patients a second operation. In other words, DC and cranioplasty essentially take place at the same time and in addition, patients retain their own bone flap. The current study conducted on animal models, represents the logical continuation of a prior recent study, realized on cadaver specimens, to assess the efficacy and safety of this recently developed device. Materials and Methods: This is an experimental pilot study on dogs to assess both safety and efficacy of the SF device. Two groups of experimental raised intracranial pressure animal models underwent DC; in the first group of dogs, the bone flap was left in raised position above the skull defect using the SF device; on the second group the flap was discarded. All dogs underwent transcranial Doppler (TCD to assess brain perfusion. Head computed tomography (CT scan to determine flap position was also obtained in the group in which the SF device was placed. Results: SF has proved to be a strong fixation device that allows satisfactory brain decompression by keeping the bone flap elevated from the swollen brain; later on, the SF allows cranial reconstruction in a simple way without requiring a second staged operation. In addition, it is relevant to note that brain perfusion was measured and found to be better in the group receiving the SF (while the flap being in a raised as well as in its natural position comparing to the other

  17. Two cases of medically-refractory spontaneous orthostatic headaches with normal cerebrospinal fluid pressures responding to epidural blood patching: Intracranial hypotension versus hypovolemia and the need for clinical awareness

    Directory of Open Access Journals (Sweden)

    Kaukab M Hassan

    2013-01-01

    Full Text Available The diagnosis of spontaneous intracranial hypotension or cerebrospinal fluid (CSF hypovolemia syndrome requires a high index of suspicion and meticulous history taking, demonstration of low CSF pressure and/or neuroimaging features. A 31-year-old male, presented with subacute onset moderate occipital and sub-occipital headaches precipitated by upright posture and relieved on recumbency and neck pain for 2 years. There was no trauma, cranial/spinal surgery. Clinical examination was normal and CSF opening pressure and laboratory study were normal. Magnetic resonance imaging (MRI brain showed thin subdural hygroma. Another patient, 41-year-old male presented with 1 month of subacute onset severe bifrontal throbbing orthostatic headaches (OHs. CSF opening pressure was normal. Contrast MRI brain showed the presence of bilateral subdural hygromas, diffuse meningeal enhancement, venous distension, sagging of the brain, and tonsillar herniation. We report two cases of "spontaneous OHs" with normal CSF pressures who were successfully treated with epidural blood patching after poor response to conservative management.

  18. Pressure Gradient Estimation Based on Ultrasonic Blood Flow Measurement

    Science.gov (United States)

    Nitta, Naotaka; Homma, Kazuhiro; Shiina, Tsuyoshi

    2006-05-01

    Mechanical load to the blood vessel wall, such as shear stress and pressure, which occurs in blood flow dynamics, contribute greatly to plaque rupture in arteriosclerosis and to biochemical activation of endothelial cells. Therefore, noninvasive estimations of these mechanical loads are able to provide useful information for the prevention of vascular diseases. Although the pressure is the dominant component of mechanical load, for practical purposes, the pressure gradient is also often important. So far, we have investigated the estimation of the kinematic viscosity coefficient using a combination of the Navier-Stokes equations and ultrasonic velocity measurement. In this paper, a method for pressure gradient estimation using the estimated kinematic viscosity coefficient is proposed. The validity of the proposed method was investigated on the basis of the analysis with the data obtained by computer simulation and a flow phantom experiment. These results revealed that the proposed method can provide a valid estimation of the pressure gradient.

  19. [Measuring pressure distribution on the human tibia in ski boots].

    Science.gov (United States)

    Schaff, P; Hauser, W

    1987-09-01

    Pressure distribution inside shoes is of great importance for orthopaedic and biomechanical inquiries. Especially in sports, safety and comfort depend essentially on this quantity, which also determines whether a shoe is well suited for a certain discipline. Therefore, the measurement of pressure distribution allows detailed and objective statements about these factors. Using a set of newly developed thin and highly flexible measuring mats and the corresponding electronic equipment, such statements have become possible. First results with this method were obtained in alpine skiing. 8 different types of ski boots (sizes 5 and 8) worn by 14 subjects were tested on different foreward leans and temperatures using 7-point measuring mats (2 cm2/point) fixed between the boot shaft and the front of the lower leg of each leg. Additional measurements on three different types of boots using a 3 x 24-point mat (1 cm2/point) for the lower leg, as well as measurements underneath the foot with a 14-point (2 cm2/point) and a 80-point (1 cm2/point) mat were performed. A complementary determination of the force at the heel element of a ski binding and a registration of muscular activity (EMG) helped in the interpretation of the results. Some field research using telemetry completed our study. Considerable variations between different boots were found in value and location of pressure maxima. Traditional boots show high pressure values over the instep at foreward leans of 35 degrees and a rise of pressure underneath the forefoot while fixing the buckles, whereas minimal pressure over the instep, no compression of the forefoot and a pressure maximum near the upper end of the shaft are observed in rear entry boots. The force at the heel-important for binding release-varies widely between different boots at the same foreward lean. There was no asymmetry between the pressure distributions of right and left. The pressure distributions for different subjects measured in the same boot were

  20. Pressure Autoregulation Measurement Techniques in Adult TBI, Part II: A Scoping Review of Continuous Methods.

    Science.gov (United States)

    Zeiler, Frederick Adam; Donnelly, Joseph; Calviello, Leanne; Smieleweski, Peter; Menon, David; Czosnyka, Marek

    2017-07-12

    To perform systematically a scoping review of the literature on commonly described continuous autoregulation measurement techniques in adult TBI. The goal was to provide an overview of methodology and comprehensive reference library of the available literature for each technique. Five separate small systematic reviews were conducted for each of the continuous techniques: pressure reactivity index (PRx), laser Doppler flowmetry (LDF), near infrared spectroscopy (NIRS) techniques, brain tissue oxygen tension (PbtO2), and thermal diffusion (TD) techniques. Articles from MEDLINE, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library (inception to December 2016) and reference lists of relevant articles were searched. A two-tier filter of references was conducted. The literature base identified from the individual searches was limited, except for PRx. The total number of articles utilizing each of the 5 searched techniques for continuous autoregulation in adult TBI were: PRx (28), LDF (4), NIRS (9), PbtO2 (10), and TD (8). All continuous techniques described in adult TBI are based on moving correlation coefficients. The premise behind the calculation of these moving correlation coefficients focuses on the impact of slow fluctuations in either MAP or CPP on some indirect measure of CBF, such as: intracranial pressure (ICP), LDF, NIRS signals, PbtO2 or TD CBF. The thought is the correlation between a hemodynamic driving factor, such as MAP or CPP, and a surrogate for CBF or cerebral perfusion sheds insight on the state of cerebral autoregulation. Both PRx and NIRS indices were validated experimentally against 'golden standard' static autoregulatory curve (Lassen curve) at least around lower threshold of autoregulation. PRx has the largest literature base supporting the association with patient outcome. Various methods of continuous autoregulation assessment are described within the adult TBI literature. Many studies exist on these various indices, suggesting an

  1. Foldable micro coils for a transponder system measuring intraocular pressure

    Energy Technology Data Exchange (ETDEWEB)

    Ullerich, S.; Schnakenberg, U. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1; Mokwa, W. [Technische Hochschule Aachen (Germany). Inst. of Materials in Electrical Engineering 1]|[Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany); Boegel, G. vom [Fraunhofer Inst. of Microelectronic Circuits and Systems, Duisburg (Germany)

    2001-07-01

    A foldable transponder system consisting of a chip and a micro coil for measuring intraocular pressure continuously is presented. The system will be integrated in the haptic of a soft artificial intraocular lens. Calculations of planar micro coils with 6 mm and 10.3 mm in diameter show the limits for planar coils with an outer diameter of 6 mm. For the realisation of the transponder system a 20 {mu}m thick coil with an outer diameter of 10.3 mm, an inner diameter of 7.7 mm, 16 turns and a gap of 20 {mu}m between the windings was selected. Measurements show a good agreement between calculated and measured values. Wireless pressure measurements were carried out showing a linear behaviour of the output signal with respect to the applied pressure. (orig.)

  2. Cardiac MR Elastography: Comparison with left ventricular pressure measurement

    Directory of Open Access Journals (Sweden)

    Samani Abbas

    2009-11-01

    Full Text Available Abstract Purpose of study To compare magnetic resonance elastography (MRE with ventricular pressure changes in an animal model. Methods Three pigs of different cardiac physiology (weight, 25 to 53 kg; heart rate, 61 to 93 bpm; left ventricular [LV] end-diastolic volume, 35 to 70 ml were subjected to invasive LV pressure measurement by catheter and noninvasive cardiac MRE. Cardiac MRE was performed in a short-axis view of the heart and applying a 48.3-Hz shear-wave stimulus. Relative changes in LV-shear wave amplitudes during the cardiac cycle were analyzed. Correlation coefficients between wave amplitudes and LV pressure as well as between wave amplitudes and LV diameter were determined. Results A relationship between MRE and LV pressure was observed in all three animals (R2 ≥ 0.76. No correlation was observed between MRE and LV diameter (R2 ≤ 0.15. Instead, shear wave amplitudes decreased 102 ± 58 ms earlier than LV diameters at systole and amplitudes increased 175 ± 40 ms before LV dilatation at diastole. Amplitude ratios between diastole and systole ranged from 2.0 to 2.8, corresponding to LV pressure differences of 60 to 73 mmHg. Conclusion Externally induced shear waves provide information reflecting intraventricular pressure changes which, if substantiated in further experiments, has potential to make cardiac MRE a unique noninvasive imaging modality for measuring pressure-volume function of the heart.

  3. Blood-Pressure Measuring System Gives Accurate Graphic Output

    Science.gov (United States)

    1965-01-01

    The problem: To develop an instrument that will provide an external (indirect) measurement of arterial blood pressure in the form of an easily interpreted graphic trace that can be correlated with standard clinical blood-pressure measurements. From sphygmograms produced by conventional sphygmographs, it is very difficult to differentiate the systolic and diastolic blood-pressure pulses and to correlate these indices with the standard clinical values. It is nearly impossible to determine these indices when the subject is under physical or emotional stress. The solution: An electronic blood-pressure system, basically similar to conventional ausculatory sphygmomanometers, employing a standard occluding cuff, a gas-pressure source, and a gas-pressure regulator and valve. An electrical output transducer senses cuff pressure, and a microphone positioned on the brachial artery under the occluding cuff monitors the Korotkoff sounds from this artery. The output signals present the conventional systolic and diastolic indices in a clear, graphical display. The complete system also includes an electronic timer and cycle-control circuit.

  4. Normal ranges and test-retest reproducibility of flow and velocity parameters in intracranial arteries measured with phase-contrast magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Correia de Verdier, Maria; Wikstroem, Johan [Uppsala University Hospital, Department of Radiology, Uppsala University, Uppsala (Sweden)

    2016-05-15

    The purpose of the present study was to investigate normal ranges and test-retest reproducibility of phase-contrast MRI (PC-MRI)-measured flow and velocity parameters in intracranial arteries. Highest flow (HF), lowest flow (LF), peak systolic velocity (PSV), and end diastolic velocity (EDV) were measured at two dates in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries of 30 healthy volunteers using two-dimensional PC-MRI at 3 T. Least detectable difference (LDD) was calculated. In the left ACA, HF was (mean (range, LDD)) 126 ml/min (36-312, 59 %), LF 61 ml/min (0-156, 101 %), PSV 64 cm/s (32-141, 67 %), and EDV 35 cm/s (18-55, 42 %); in the right ACA, HF was 154 ml/min (42-246, 49 %), LF 77 ml/min (0-156, 131 %), PSV 75 cm/s (26-161, 82 %), and EDV 39 cm/s (7-59, 67 %). In the left MCA, HF was 235 ml/min (126-372, 35 %), LF 116 ml/min (42-186, 48 %), PSV 90 cm/s (55-183, 39 %), and EDV 46 cm/s (20-66, 28 %); in the right MCA, HF was 238 ml/min (162-342, 44 %), LF 120 ml/min (72-216, 48 %), PSV 88 cm/s (55-141, 35 %), and EDV 45 cm/s (26-67, 23 %). In the left PCA, HF was 108 ml/min (42-168, 54 %), LF 53 ml/min (18-108, 64 %), PSV 50 cm/s (24-77, 63 %), and EDV 28 cm/s (14-40, 45 %); in the right PCA, HF was 98 ml/min (30-162, 49 %), LF 49 ml/min (12-84, 55 %), PSV 47 cm/s (27-88, 59 %), and EDV 27 cm/s (16-41, 45 %). PC-MRI-measured flow and velocity parameters in the main intracranial arteries have large normal ranges. Reproducibility is highest in MCA. (orig.)

  5. Measuring air pressure with a polymeric gas sensor

    Directory of Open Access Journals (Sweden)

    Juliana R. Cordeiro

    2010-01-01

    Full Text Available In this communication we describe the application of a conductive polymer gas sensor as an air pressure sensor. The device consists of a thin doped poly(4'-hexyloxy-2,5-biphenylene ethylene (PHBPE film deposited on an interdigitated metallic electrode. The sensor is cheap, easy to fabricate, lasts for several months, and is suitable for measuring air pressures in the range between 100 and 700 mmHg.

  6. Treatment of intracranial hydatid cysts

    Institute of Scientific and Technical Information of China (English)

    Sailike Duishanbai; WEN Hao; GENG Dangmurenjiafu; LIU Chen; GUO Huai-rong; HAO Yu-jun; LIU Bo; WANG Yong-xin; LUO Kun; ZHOU Kai

    2011-01-01

    main cause of increased intracranial pressure among the patients in endemic areas for echinococcosis. CT and MRI are the best diagnostic methods and surgery is the treatment of choice for intracranial hydatid cysts.

  7. Hugoniot measurements at near Gbar pressures at the NIF

    Science.gov (United States)

    Kritcher, Andrea; Swift, Damian; Doeppner, Tilo; Collins, Gilbert; Bachmann, Benjamin; Nilsen, Joe; Chapman, Dave; Correa, Alfredo; Sterne, Phil; Benedict, Lorin; Gaffney, Jim; Kraus, Dominik; Falcone, Roger; Glenzer, Siegfried; Rothman, Steve

    2015-11-01

    Laboratory measurements of the Equation of State (EOS) of matter at high pressure are of great importance in the understanding and accurate modeling of matter at extreme conditions. For example, at hundreds of Mbars - Gbar pressures atomic shell effects may come into play, which can change the predicted compressibility at given pressure due to pressure and temperature ionization. In this work we present measurements of the strong shock hugoniot, at pressures up to 720 Mbar for CH and 630 Mbar for High Density Carbon (HDC, or diamond) at the National Ignition Facility (NIF). Spherically convergent shocks are launched into solid CH or diamond samples, using a hohlraum radiation drive. X-ray radiography is applied to measure the shock speed and infer the mass density profile, enabling determining of the shock pressure and Hugoniot equation of state. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. Supported by LDRD 08-ERI-003.

  8. Blood pressure monitor with a position sensor for wrist placement to eliminate hydrostatic pressure effect on blood pressure measurement.

    Science.gov (United States)

    Sato, Hironori; Koshimizu, Hiroshi; Yamashita, Shingo; Ogura, Toshihiko

    2013-01-01

    Accurate measurement of blood pressure at wrist requires the heart and wrist to be kept at the same level to avoid the effects of hydrostatic pressure. Although a blood pressure monitor with a position sensor that guides appropriate forearm angle without use of a chair and desk has already been proposed, a similar functioning device for measuring upper arm blood pressure with a chair and desk is needed. In this study, a calculation model was first used to explore design of such a system. The findings were then implemented into design of a new blood pressure monitor. Results of various methods were compared. The calculation model of the wrist level from arthrosis angles and interarticulars lengths was developed and considered using published anthropometric dimensions. It is compared with 33 volunteer persons' experimental results. The calculated difference of level was -4.1 to 7.9 (cm) with a fixed chair and desk. The experimental result was -3.0 to 5.5 (cm) at left wrist and -2.1 to 6.3(cm) at right wrist. The absolute difference level equals ±4.8 (mmHg) of blood pressure readings according to the calculated result. This meets the AAMI requirements for a blood pressure monitor. In the conclusion, the calculation model is able to effectively evaluate the difference between the heart and wrist level. Improving the method for maintaining wrist to heart level will improve wrist blood pressure measurement accuracy when also sitting in the chair at a desk. The leading angle of user's forearm using a position sensor is shown to work for this purpose.

  9. Miniature optical fiber pressure microsensors for in vivo measurement of intramuscular pressure

    Science.gov (United States)

    Cottler, P. S.; Blevins, D.; Averett, J.; Wavering, T. A.; Morrow, D. A.; Shin, A. Y.; Kaufman, K. R.

    2007-02-01

    An innovative fiber optic pressure microsensor has been developed that is based upon on Luna Innovations' patented extrinsic Fabry-Perot interferometric (EFPI) technique. The basic physics governing the operation of these sensors makes them relatively tolerant or immune to the effects of high-temperature, high-EMI, and highly-corrosive environments. Luna's pressure microsensor is extremely small, with an outer diameter of only 200 microns and a length of less than 1mm. The pressure microsensor has a high sensitivity that allows for sub-mmHg resolution over a dynamic range of 0-300 mmHg. The combination of these features makes this pressure microsensor ideal for medical applications where small size, high sensitivity and accuracy, EMI immunity, biocompatibility, and survivability (e.g. sterilizable - steam, ethylene oxide) are important. One example medical application of the pressure microsensor has been to adapt the microsensor for measurement of intramuscular pressure in vivo during active and passive muscle activation. Clinically it is difficult to study the in vivo mechanical properties of individual skeletal muscles for a variety of reasons. Initial experiments have demonstrated a correlation between intramuscular pressure and force. Such measurements can be a useful diagnostic tool for clinicians assessing muscular deficits in patients.

  10. Wavenumber-frequency Spectra of Pressure Fluctuations Measured via Fast Response Pressure Sensitive Paint

    Science.gov (United States)

    Panda, J.; Roozeboom, N. H.; Ross, J. C.

    2016-01-01

    The recent advancement in fast-response Pressure-Sensitive Paint (PSP) allows time-resolved measurements of unsteady pressure fluctuations from a dense grid of spatial points on a wind tunnel model. This capability allows for direct calculations of the wavenumber-frequency (k-?) spectrum of pressure fluctuations. Such data, useful for the vibro-acoustics analysis of aerospace vehicles, are difficult to obtain otherwise. For the present work, time histories of pressure fluctuations on a flat plate subjected to vortex shedding from a rectangular bluff-body were measured using PSP. The light intensity levels in the photographic images were then converted to instantaneous pressure histories by applying calibration constants, which were calculated from a few dynamic pressure sensors placed at selective points on the plate. Fourier transform of the time-histories from a large number of spatial points provided k-? spectra for pressure fluctuations. The data provides first glimpse into the possibility of creating detailed forcing functions for vibro-acoustics analysis of aerospace vehicles, albeit for a limited frequency range.

  11. High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, E A; Tan, N

    2010-04-21

    High pressure deflagration rate measurements of a unique ammonium perchlorate (AP) based propellant are required to design the base burn motor for a Raytheon weapon system. The results of these deflagration rate measurements will be key in assessing safety and performance of the system. In particular, the system may experience transient pressures on the order of 100's of MPa (10's kPSI). Previous studies on similar AP based materials demonstrate that low pressure (e.g. P < 10 MPa or 1500 PSI) burn rates can be quite different than the elevated pressure deflagration rate measurements (see References and HPP results discussed herein), hence elevated pressure measurements are necessary in order understand the deflagration behavior under relevant conditions. Previous work on explosives have shown that at 100's of MPa some explosives will transition from a laminar burn mechanism to a convective burn mechanism in a process termed deconsolidative burning. The resulting burn rates that are orders-of-magnitude faster than the laminar burn rates. Materials that transition to the deconsolidative-convective burn mechanism at elevated pressures have been shown to be considerably more violent in confined heating experiments (i.e. cook-off scenarios). The mechanisms of propellant and explosive deflagration are extremely complex and include both chemical, and mechanical processes, hence predicting the behavior and rate of a novel material or formulation is difficult if not impossible. In this work, the AP/HTPB based material, TAL-1503 (B-2049), was burned in a constant volume apparatus in argon up to 300 MPa (ca. 44 kPSI). The burn rate and pressure were measured in-situ and used to calculate a pressure dependent burn rate. In general, the material appears to burn in a laminar fashion at these elevated pressures. The experiment was reproduced multiple times and the burn rate law using the best data is B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} where B is the burn

  12. Are the Intracranial Lipomas Always Asymptomatic?

    Directory of Open Access Journals (Sweden)

    Mustafa Yilmaz

    2014-02-01

    Full Text Available Intracranial lipomas are rarely observed, and accepted as the congenital lesion of central nervous system. Intracranial lipomas are usually based centrally and have benign character. In the brain, it is mostly localized in pericallosal region, quadrigeminal system, and suprasellar region and cerebellopontine angles. As being mostly asymptomatic, the patients occasionally constitute clinical symptoms according to localization area. These symptoms are systemic symptoms such as cephalalgia, drowsiness, crisis and ataxy. In this article, we aimed to present the intracranial lipomas phenomenon which was diagnosed to have caused ptosis and upper lateral sight problem, namely causing localized neurological symptom, situated in mesencephalon and having pressure effect, regarding a 57-year old male patient brought to the emergency service with the nausea, throwing up and cephalalgia ailments.

  13. Idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Yri, Hanne M; Jensen, Rigmor H

    2015-01-01

    AIMS: The aims of this article are to characterize the headache in idiopathic intracranial hypertension (IIH) and to field-test the ICHD diagnostic criteria for headache attributed to IIH. MATERIALS AND METHODS: We included 44 patients with new-onset IIH. Thirty-four patients with suspected...... tinnitus may suggest intracranial hypertension. Based on data from a well-defined IIH cohort, we propose a revision of the ICDH-3 beta diagnostic criteria with improved clinical applicability and increased sensitivity and specificity....

  14. MRI-derived measurements of human subcortical, ventricular and intracranial brain volumes: Reliability effects of scan sessions, acquisition sequences, data analyses, scanner upgrade, scanner vendors and field strengths.

    Science.gov (United States)

    Jovicich, Jorge; Czanner, Silvester; Han, Xiao; Salat, David; van der Kouwe, Andre; Quinn, Brian; Pacheco, Jenni; Albert, Marilyn; Killiany, Ronald; Blacker, Deborah; Maguire, Paul; Rosas, Diana; Makris, Nikos; Gollub, Randy; Dale, Anders; Dickerson, Bradford C; Fischl, Bruce

    2009-05-15

    Automated MRI-derived measurements of in-vivo human brain volumes provide novel insights into normal and abnormal neuroanatomy, but little is known about measurement reliability. Here we assess the impact of image acquisition variables (scan session, MRI sequence, scanner upgrade, vendor and field strengths), FreeSurfer segmentation pre-processing variables (image averaging, B1 field inhomogeneity correction) and segmentation analysis variables (probabilistic atlas) on resultant image segmentation volumes from older (n=15, mean age 69.5) and younger (both n=5, mean ages 34 and 36.5) healthy subjects. The variability between hippocampal, thalamic, caudate, putamen, lateral ventricular and total intracranial volume measures across sessions on the same scanner on different days is less than 4.3% for the older group and less than 2.3% for the younger group. Within-scanner measurements are remarkably reliable across scan sessions, being minimally affected by averaging of multiple acquisitions, B1 correction, acquisition sequence (MPRAGE vs. multi-echo-FLASH), major scanner upgrades (Sonata-Avanto, Trio-TrioTIM), and segmentation atlas (MPRAGE or multi-echo-FLASH). Volume measurements across platforms (Siemens Sonata vs. GE Signa) and field strengths (1.5 T vs. 3 T) result in a volume difference bias but with a comparable variance as that measured within-scanner, implying that multi-site studies may not necessarily require a much larger sample to detect a specific effect. These results suggest that volumes derived from automated segmentation of T1-weighted structural images are reliable measures within the same scanner platform, even after upgrades; however, combining data across platform and across field-strength introduces a bias that should be considered in the design of multi-site studies, such as clinical drug trials. The results derived from the young groups (scanner upgrade effects and B1 inhomogeneity correction effects) should be considered as preliminary and in

  15. System for water level measurement based on pressure transducer

    Science.gov (United States)

    Paczesny, Daniel; Marzecki, Michał; Woyke, Michał; Tarapata, Grzegorz

    2016-09-01

    The paper reports system for water level measurement, which is designed to be used for measuring liquid levels in the tanks of an autonomous industrial cleaning robot. The selected method of measurement utilized by the designed system is based on pressure measurement. Such system is insensitive on vibrations, foams presence and liquid impurities. The influences of variable pressure on the measurements were eliminated by utilizing the differential method and as well as the system design. The system is capable of measuring water level in tanks up to 400 mm of height with accuracy of about 2,5%. The system was tested in a container during filling and emptying with various liquids. Performed tests exhibited the linearity of the sensor characteristic and the lack of hysteresis. Obtained sensitivity of the sensor prototype was approximately 6,2 mV/mm H2O.

  16. Study on Intracranial Pressure Changes with Transcranial Doppler Ultrasound in Patients with Intracerebral Haemorrhage%脑出血患者经颅多普勒超声评估颅内压变化研究

    Institute of Scientific and Technical Information of China (English)

    吴建维; 贾娇坤; 丁则昱; 赵性泉

    2016-01-01

    目的为进一步验证脑出血患者颅内压(intracranial pressure,ICP)与经颅多普勒超声(transcranial Doppler ultrasound,TCD)血流参数间的相关性,确立脑出血患者TCD血流参数预测ICP的最优数学模型并评价其预测准确性。  方法根据纳入、排除标准,共登记22例脑出血患者的人口学资料、主要神经功能评分和病灶特征资料,所有患者行持续床旁脑实质颅内压监测,期间每天复查TCD,监测大脑中动脉(middle cerebral artery,MCA)及颈内动脉(internal carotid artery,ICA)血流参数并记录即时ICP数值、体温、血压、心率和血氧饱和度等。筛选最优TCD血流参数,对即时ICP与TCD血流参数行相关性分析及多元线性回归分析,建立TCD参数评估ICP数学模型,并对其诊断颅高压(ICP>15 mmHg)的准确性进行评价。  结果相关性分析示脉搏指数(pulsatility index,PI)与ICP呈正相关,相关系数为r=0.66(P15 mmHg)时,ICPe的曲线下面积为0.93,95%可信区间为0.88~0.97。  结论 TCD血流参数PI与ICP呈正相关,是预测ICP最重要的指标。ICPe=-16.8+26.8×PI+0.12×Vm(调整R2为0.46)可准确诊断颅高压(ICP>15 mmHg)。%Objective To further verify the correlation between intracranial pressure (ICP) and blood flow parameters of transcranial Doppler ultrasound (TCD) in patients with cerebral hemorrhage. The optimal mathematical models of intracranial pressure were established, which were predicted quantitatively by blood lfow parameters of TCD, and then evaluated the accuracy. Methods According to the inclusion and exclusion criteria, demographic data, major neurological function scores and characteristics of lesions of 22 patients with cerebral hemorrhage were registered. The intracranial pressure monitor was used to monitor the intraparenchymal pressure continuously at the bedside. TCD detection was reviewed daily. The blood lfow

  17. Dynamic tire pressure sensor for measuring ground vibration.

    Science.gov (United States)

    Wang, Qi; McDaniel, James Gregory; Wang, Ming L

    2012-11-07

    This work presents a convenient and non-contact acoustic sensing approach for measuring ground vibration. This approach, which uses an instantaneous dynamic tire pressure sensor (DTPS), possesses the capability to replace the accelerometer or directional microphone currently being used for inspecting pavement conditions. By measuring dynamic pressure changes inside the tire, ground vibration can be amplified and isolated from environmental noise. In this work, verifications of the DTPS concept of sensing inside the tire have been carried out. In addition, comparisons between a DTPS, ground-mounted accelerometer, and directional microphone are made. A data analysis algorithm has been developed and optimized to reconstruct ground acceleration from DTPS data. Numerical and experimental studies of this DTPS reveal a strong potential for measuring ground vibration caused by a moving vehicle. A calibration of transfer function between dynamic tire pressure change and ground acceleration may be needed for different tire system or for more accurate application.

  18. Innovations in plantar pressure and foot temperature measurements in diabetes.

    Science.gov (United States)

    Bus, S A

    2016-01-01

    Plantar pressure and temperature measurements in the diabetic foot primarily contribute to identifying abnormal values that increase risk for foot ulceration, and they are becoming increasingly more integrated in clinical practice and daily life of the patient. While plantar pressure measurements have long been present, only recently evidence shows their importance in ulcer prevention, as a data-driven approach to therapeutic footwear provision. The long-term monitoring of plantar pressures with the option to provide feedback, when alarming pressure levels occur, is a promising development in this area, although more technical and clinical validation is required. Shear is considered important in ulcer aetiology but is technically difficult to measure. Innovative research is underway to assess if foot temperature can act as a useful surrogate for shear. Because the skin heats up before it breaks down, frequent monitoring of foot temperature can identify these warning signals. This approach has shown to be effective in preventing foot ulcers. Innovation in diagnostic methods for foot temperature monitoring and evidence on cost effectiveness will likely facilitate implementation. Finally, monitoring of adherence to offloading treatment using temperature-based sensors has proven to be a feasible and relevant method with a wide range of possible research and patient care applications. These innovations in plantar pressure and temperature measurements illustrate an important transfer in diabetic foot care from subjective to objective evaluation of the high-risk patient. They demonstrate clinical value and a large potential in helping to reduce the patient and economic burden of diabetic foot disease.

  19. Detecting deterministic nature of pressure measurements from a turbulent combustor

    Science.gov (United States)

    Tony, J.; Gopalakrishnan, E. A.; Sreelekha, E.; Sujith, R. I.

    2015-12-01

    Identifying nonlinear structures in a time series, acquired from real-world systems, is essential to characterize the dynamics of the system under study. A single time series alone might be available in most experimental situations. In addition to this, conventional techniques such as power spectral analysis might not be sufficient to characterize a time series if it is acquired from a complex system such as a thermoacoustic system. In this study, we analyze the unsteady pressure signal acquired from a turbulent combustor with bluff-body and swirler as flame holding devices. The fractal features in the unsteady pressure signal are identified using the singularity spectrum. Further, we employ surrogate methods, with translational error and permutation entropy as discriminating statistics, to test for determinism visible in the observed time series. In addition to this, permutation spectrum test could prove to be a robust technique to characterize the dynamical nature of the pressure time series acquired from experiments. Further, measures such as correlation dimension and correlation entropy are adopted to qualitatively detect noise contamination in the pressure measurements acquired during the state of combustion noise. These ensemble of measures is necessary to identify the features of a time series acquired from a system as complex as a turbulent combustor. Using these measures, we show that the pressure fluctuations during combustion noise has the features of a high-dimensional chaotic data contaminated with white and colored noise.

  20. A Computer Controlled Precision High Pressure Measuring System

    Science.gov (United States)

    Sadana, S.; Yadav, S.; Jha, N.; Gupta, V. K.; Agarwal, R.; Bandyopadhyay, A. K.; Saxena, T. K.

    2011-01-01

    A microcontroller (AT89C51) based electronics has been designed and developed for high precision calibrator based on Digiquartz pressure transducer (DQPT) for the measurement of high hydrostatic pressure up to 275 MPa. The input signal from DQPT is converted into a square wave form and multiplied through frequency multiplier circuit over 10 times to input frequency. This input frequency is multiplied by a factor of ten using phased lock loop. Octal buffer is used to store the calculated frequency, which in turn is fed to microcontroller AT89C51 interfaced with a liquid crystal display for the display of frequency as well as corresponding pressure in user friendly units. The electronics developed is interfaced with a computer using RS232 for automatic data acquisition, computation and storage. The data is acquired by programming in Visual Basic 6.0. This system is interfaced with the PC to make it a computer controlled system. The system is capable of measuring the frequency up to 4 MHz with a resolution of 0.01 Hz and the pressure up to 275 MPa with a resolution of 0.001 MPa within measurement uncertainty of 0.025%. The details on the hardware of the pressure measuring system, associated electronics, software and calibration are discussed in this paper.

  1. Noninvasive blood pressure measurement scheme based on optical fiber sensor

    Science.gov (United States)

    Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

    2016-10-01

    Optical fiber sensing has many advantages, such as volume small, light quality, low loss, strong in anti-jamming. Since the invention of the optical fiber sensing technology in 1977, optical fiber sensing technology has been applied in the military, national defense, aerospace, industrial, medical and other fields in recent years, and made a great contribution to parameter measurement in the environment under the limited condition .With the rapid development of computer, network system, the intelligent optical fiber sensing technology, the sensor technology, the combination of computer and communication technology , the detection, diagnosis and analysis can be automatically and efficiently completed. In this work, we proposed a noninvasive blood pressure detection and analysis scheme which uses optical fiber sensor. Optical fiber sensing system mainly includes the light source, optical fiber, optical detector, optical modulator, the signal processing module and so on. wavelength optical signals were led into the optical fiber sensor and the signals reflected by the human body surface were detected. By comparing actual testing data with the data got by traditional way to measure the blood pressure we can establish models for predicting the blood pressure and achieve noninvasive blood pressure measurement by using spectrum analysis technology. Blood pressure measurement method based on optical fiber sensing system is faster and more convenient than traditional way, and it can get accurate analysis results in a shorter period of time than before, so it can efficiently reduce the time cost and manpower cost.

  2. Pressure-Sensitive Paint Measurements of Transient Shock Phenomena

    Directory of Open Access Journals (Sweden)

    Konstantinos Kontis

    2013-04-01

    Full Text Available Measurements of the global pressure field created by shock wave diffraction have been captured optically using a porous pressure-sensitive paint. The pressure field created by a diffracting shock wave shows large increases and decreases in pressure and can be reasonably accurately captured using CFD. The substrate, a thin-layer chromatography (TLC plate, has been dipped in a luminophore solution. TLC plates are readily available and easy to prepare. Illumination comes from two high-intensity broadband Xenon arc light sources with short-pass filters. The sample is imaged at 100 kHz using a Vision Research Phantom V710 in conjunction with a pair of long and short pass filters, creating a band. The PSP results are compared with numerical simulations of the flow using the commercial CFD package Fluent as part of ANSYS 13 for two Mach numbers.

  3. Measuring Surface Pressure on Rotating Compressor Blades Using Pressure Sensitive Paint

    Directory of Open Access Journals (Sweden)

    Markus Pastuhoff

    2016-03-01

    Full Text Available Pressure sensitive paint (PSP was used to measure pressure on the blades of a radial compressor with a 51 mm inlet diameter rotating at speeds up to 50 krpm using the so called lifetime method. A diode laser with a scanning-mirror system was used to illuminate the paint and the luminescent lifetime was registered using a photo multiplier. With the described technique the surface-pressure fields were acquired for eight points in the compressor map, useful for general understanding of the flow field and for CFD validation. The PSP was of so called fast type, which makes it possible to observe pressure variations with frequencies up to several kHz. Through frequency spectrum analysis we were able to detect the pulsating flow frequency when the compressor was driven to surge.

  4. A novel approach to office blood pressure measurement: 30-minute office blood pressure vs daytime ambulatory blood pressure

    NARCIS (Netherlands)

    Wel, M.C. van der; Buunk, I.E.; Weel, C. van; Thien, Th.; Bakx, J.C.

    2011-01-01

    PURPOSE: Current office blood pressure measurement (OBPM) is often not executed according to guidelines and cannot prevent the white-coat effect. Serial, automated, oscillometric OBPM has the potential to overcome both these problems. We therefore developed a 30-minute OBPM method that we compared

  5. Management of Cerebellar Tonsillar Herniation following Lumbar Puncture in Idiopathic Intracranial Hypertension

    Directory of Open Access Journals (Sweden)

    Kenneth R. Hoffman

    2015-01-01

    Full Text Available Lumbar puncture is performed routinely for diagnostic and therapeutic purposes in idiopathic intracranial hypertension, despite lumbar puncture being classically contraindicated in the setting of raised intracranial pressure. We report the case of a 30-year-old female with known idiopathic intracranial hypertension who had cerebellar tonsillar herniation following therapeutic lumbar puncture. Management followed guidelines regarding treatment of traumatic intracranial hypertension, including rescue decompressive craniectomy. We hypothesize that the changes in brain compliance that are thought to occur in the setting of idiopathic intracranial hypertension are protective against further neuronal injury due to axonal stretch following decompressive craniectomy.

  6. Blood Pressure Is the Determinant for the Increased Risk for Intracranial Arterial Stenosis in Subjects with Elevated Glycated Hemoglobin Levels: The Kangbuk Samsung Health Study.

    Science.gov (United States)

    Oh, Hyung-Geun; Rhee, Eun-Jung

    2016-11-01

    Ischemic stroke is known to be an important vascular complication of diabetes. Intracranial arterial stenosis (ICAS) is considered as an important cause of stroke in Asians. We aimed to analyze the risk for ICAS assessed by transcranial Doppler (TCD) ultrasonography in different groups of young Korean subjects divided by glycated hemoglobin (HbA1c) levels. This study included 10,437 participants without history of cardiovascular diseases (81.3% men, mean age 43 years) from a health screening program, in whom TCD ultrasonography was used to detect greater than 50% ICAS based on criteria modified from the SONIA (Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis) trial. The subjects were divided into 3 groups according to HbA1c levels: HbA1c < 5.7%, 5.7 ≤ HbA1c < 6.5%, and HbA1c ≥ 6.5% or under medication for diabetes. Among the participants, 3.0% of the subjects had ICAS. The subjects with ICAS tended to have higher mean HbA1c level compared with those without ICAS (5.8 ± .8 versus 5.7 ± .6, P = .063). The proportion of subjects with ICAS significantly increased as the HbA1c increased from the first to the third group (2.8%, 3.0%, 4.6%, P for linear trend = .022). In logistic regression analysis with ICAS as the dependent variable, the group with HbA1c ≥ 6.5% showed significantly increased odds ratio for ICAS with subjects with HbA1c < 5.7% as the reference after adjustment for confounding variables (1.575, 95% confidence interval 1.056-2.347). However, this significance disappeared with inclusion of presence of hypertension in the model. The risk for ICAS assessed by TCD was increased in young Korean subjects with HbA1c ≥ 6.5%. However, this significance was attenuated after adjustment for presence of hypertension, suggesting the importance of hypertension in ICAS. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  7. Nocturnal blood pressure and intraocular pressure measurement in glaucoma patients and healthy controls.

    Science.gov (United States)

    Follmann, P; Palotás, C; Süveges, I; Petrovits, A

    Daytime and nocturnal intraocular pressure (IOP) values and systemic blood pressure (BP) values were compared in 60 non-glaucomatous controls, 54 glaucoma patients with normal visual field, and 46 glaucoma patients with visual field loss. The daytime IOP was measured with a Goldmann applanation tonometer and the nocturnal IOP with a Bio-Rad-Tono-Pen 2. The BP was measured with either a mercury manometer or with a Meditech ABPM-02 Ambulatory Blood Pressure Monitor, which took BP readings at 60 minute intervals. A tendency towards increasing IOP and decreasing BP was detected in the non-glaucomatous controls, within normal limits, and pathological changes of IOP and BP were observed with a significantly high occurrence (5% > P > 2%; Pearson's chi 2-test) in the glaucoma group with visual field loss.

  8. Model-free measurement of exchange market pressure

    NARCIS (Netherlands)

    F.J.G.M. Klaassen; H. Jager

    2006-01-01

    If there is exchange market pressure (EMP), monetary authorities can use the interest rate and official interventions to offset this depreciation tendency, or they can let the exchange rate change. We introduce a new approach to derive how these three variables should be combined to measure EMP. Thi

  9. Pitfalls in blood pressure measurement in daily practice

    NARCIS (Netherlands)

    Houweling, ST; Kleefstra, N; Lutgers, HL; Groenier, KH; Meyboom-de Jong, B; Bilo, HJG

    2006-01-01

    Background. Accurate blood pressure (BP) readings and correctly interpreting the obtained values are of great importance. However, there is considerable variation in the different BP measuring methods suggested in guidelines and used in hypertension trials. Objective. To compare the different method

  10. Combination of phlebography and sanguinous measurement of venous blood pressure

    Energy Technology Data Exchange (ETDEWEB)

    Weber, J.

    1988-07-01

    Phlebographic visualisation offers the highest spatial resolution of all imaging methods both in respect of veins of the leg and pelvis and of the abdomen. Phlebography offers optimal conditions for assessing morphological changes at the veins and in their direct neighbourhood. No quantitative information is available via phlebography if haemodynamics are disturbed; qualitative information is yielded merely to a restricted extent (by assessing flow velocity and collaterals). Direct sanguinous measurement of venous blood pressure is particularly suitable for the quantitative and qualitative assessment of disturbed haemodynamic conditions; in this respect it stands out among the function tests based on the employment of apparatures. If it is combined with phlebography, it is possible not only to optimise the diagnostic yield in the hands of one investigator, but also to reduce the invasiveness of both methods to one single puncture, since the puncture needle is at the same time also an instrument to measure the pressure. The article points out the possibilities and limitations of combining a) ascending phlebography of the leg and pelvis with peripheral venous pressure measurement (phlebodynamometry) and b) visualisation of the veins of the pelvis and vena cava inferior with central sanguinous venous pressure measurement (CP). Indicatious and technical execution are described.

  11. Measuring occupational stress: development of the pressure management indicator.

    Science.gov (United States)

    Williams, S; Cooper, C L

    1998-10-01

    The study of occupational stress is hindered by the lack of compact and comprehensive standardized measurement tools. The Pressure Management Indicator (PMI) is a 120-item self-report questionnaire developed from the Occupational Stress Indicator (OSI). The PMI is more reliable, more comprehensive, and shorter than the OSI. It provides an integrated measure of the major dimensions of occupational stress. The outcome scales measure job satisfaction, organizational satisfaction, organizational security, organizational commitment, anxiety--depression, resilience, worry, physical symptoms, and exhaustion. The stressor scales cover pressure from workload, relationships, career development, managerial responsibility, personal responsibility, home demands, and daily hassles. The moderator variables measure drive, impatience, control, decision latitude, and the coping strategies of problem focus, life work balance, and social support.

  12. Gas Pressure Measurements on Space Shuttle Mission-39.

    Science.gov (United States)

    2007-11-02

    there have been numerous in-situ experiments designed to measure the gaseous contamination near the Shuttle [Green et al., 1985; Erlers et al., 1984...engines [ Erlers , 1984; Machuzak et al., 1993; Hunton, 19941. Engine-related pressure spikes were investigated by Narcisi et al. [19831, Wulf and von Zahn...Government Printing Office, Washington D.C., 1976. Erlers , H.K.F., S. Jacobs, L. Leger, and E. Miller (1984) Space Shuttle contamination measurements from

  13. Dynamic material strength measurement utilizing magnetically applied pressure-shear

    Directory of Open Access Journals (Sweden)

    Alexander C.S.

    2012-08-01

    Full Text Available Magnetically applied pressure-shear (MAPS is a recently developed technique used to measure dynamic material strength developed at Sandia National Laboratories utilizing magneto-hydrodynamic (MHD drive pulsed power systems. MHD drive platforms generate high pressures by passing a large current through a pair of parallel plate conductors which, in essence, form a single turn magnet coil. Lorentz forces resulting from the interaction of the self-generated magnetic field and the drive current repel the plates and result in a high pressure ramp wave propagating in the conductors. This is the principle by which the Sandia Z Machine operates for dynamic material testing. MAPS relies on the addition of a second, external magnetic field applied orthogonally to both the drive current and the self-generated magnetic field. The interaction of the drive current and this external field results in a shear wave being induced directly in the conductors. Thus both longitudinal and shear stresses are generated. These stresses are coupled to a sample material of interest where shear strength is probed by determining the maximum transmissible shear stress in the state defined by the longitudinal compression. Both longitudinal and transverse velocities are measured via a specialized velocity interferometer system for any reflector (VISAR. Pressure and shear strength of the sample are calculated directly from the VISAR data. Results of tests on several materials at modest pressures (∼10GPa will be presented and discussed.

  14. Assessment of pressure field calculations from particle image velocimetry measurements

    Science.gov (United States)

    Charonko, John J.; King, Cameron V.; Smith, Barton L.; Vlachos, Pavlos P.

    2010-10-01

    This paper explores the challenges associated with the determination of in-field pressure from DPIV (digital particle image velocimetry)-measured planar velocity fields for time-dependent incompressible flows. Several methods that have been previously explored in the literature are compared, including direct integration of the pressure gradients and solution of different forms of the pressure Poisson equations. Their dependence on grid resolution, sampling rate, velocity measurement error levels and off-axis recording was quantified using artificial data of two ideal sample flow fields—a decaying vortex flow and pulsatile flow between two parallel plates, and real DPIV and pressure data from oscillating flow through a diffuser. The need for special attention to mitigate the velocity error propagation in the pressure estimation is also addressed using a physics-preserving approach based on proper orthogonal decomposition (POD). The results demonstrate that there is no unique or optimum method for estimating the pressure field and the resulting error will depend highly on the type of the flow. However, the virtual boundary, omni-directional pressure integration scheme first proposed by Liu and Katz (2006 Exp. Fluids 41 227-40) performed consistently well in both synthetic and experimental flows. Estimated errors can vary from less than 1% to over 100% with respect to the expected value, though in contrast to more traditional smoothing algorithms, the newly proposed POD-based filtering approach can reduce errors for a given set of conditions by an order of magnitude or more. This analysis offers valuable insight that allows optimizing the choice of methods and parameters based on the flow under consideration.

  15. A lidar system for measuring atmospheric pressure and temperature profiles

    Science.gov (United States)

    Schwemmer, Geary K.; Dombrowski, Mark; Korb, C. Laurence; Milrod, Jeffry; Walden, Harvey

    1987-01-01

    The design and operation of a differential absorption lidar system capable of remotely measuring the vertical structure of tropospheric pressure and temperature are described. The measurements are based on the absorption by atmospheric oxygen of the spectrally narrowband output of two pulsed alexandrite lasers. Detailed laser output spectral characteristics, which are critical to successful lidar measurements, are presented. Spectral linewidths of 0.026 and 0.018 per cm for the lasers were measured with over 99.99 percent of the energy contained in three longitudinal modes.

  16. Pediatric Idiopathic Intracranial Hypertension: A Case Report

    Directory of Open Access Journals (Sweden)

    Divya Nandwani, OD

    2015-08-01

    Full Text Available Background: Idiopathic intracranial hypertension (IIH presents differently in prepubertal children as compared to postpubertal children and adults. In adults, IIH is most common in obese women of child-bearing age. However, when occurring in prepubertal children, IIH has been shown to have no predilection for gender and does not correlate with obesity. This case report exemplifies the rare occurrence of IIH in a pediatric patient. Case Report: A five-year-old Hispanic female patient was seen at the University Eye Center for a longstanding hypotropia secondary to a likely congenital fourth nerve palsy with an exotropia component. After a strabismus surgery and a series of follow-up visits, bilateral swollen optic nerves were observed, and a prompt referral to the emergency room was made. Consequently, she was diagnosed with IIH. A treatment regimen of acetazolamide was initiated with subsequent improvement of the clinical presentation of increased intracranial pressure, confirmed by the reduction of swelling of her optic nerves. Conclusions: Bilateral swelling of the optic nerves can be an emergency, especially in children. It is important urgently to rule out causes for increased intracranial pressure. If treatment is significantly delayed, or if no treatment is given to a patient with this condition, loss of visual function may occur. In addition to reporting a rare circumstance of pediatric idiopathic intracranial hypertension, this case report serves to remind eye care practitioners of the importance of monitoring the ocular health of patients closely, even in young, healthy children.

  17. Evaluation of automated blood pressure measurements during exercise testing.

    Science.gov (United States)

    Hossack, K F; Gross, B W; Ritterman, J B; Kusumi, F; Bruce, R A

    1982-11-01

    Measurements of systolic (SBP) and diastolic (DBP) blood pressure were made at rest and during symptom-limited exercise with an automated blood pressure measuring device (EBPM). Comparisons were made between the EBPM readings and those made with mercury manometer. Correlations were high (SBP r = 0.92, DBP r = 0.80) when readings were made in the same arm, but were less satisfactory when the cuffs were on different arms (SBP r = 0.80, DBP r = 0.46). The correlation between two mercury manometer readings was SBP r = 0.90, and DBP r = 0.75. Comparison between EBPM and intra-arterial measurements were similar (SBP r = 0.74, DBP r = 0.79) to comparison between mercury manometer and intra-arterial measurements (SBP r = 0.81, DBP r = 0.61). The EBPM detected SBP at consistently higher levels than did physicians, which may be an advantage in the noisy environment of an exercise test. There was a definite tendency for physicians to record blood pressure to the nearest 10 mm Hg, whereas the frequency distribution curve for EBPM measurements was smoother. The EBPM operated satisfactorily at rest and during maximal exercise and gave as reliable measurements as a physician using a mercury manometer and, in the small number of available cases, detected exertional hypotension more often than the physician.

  18. Hyperprolactinemia due to spontaneous intracranial hypotension.

    Science.gov (United States)

    Schievink, Wouter I; Nuño, Miriam; Rozen, Todd D; Maya, M Marcel; Mamelak, Adam N; Carmichael, John; Bonert, Vivien S

    2015-05-01

    OBJECT Spontaneous intracranial hypotension is an increasingly recognized cause of headaches. Pituitary enlargement and brain sagging are common findings on MRI in patients with this disorder. The authors therefore investigated pituitary function in patients with spontaneous intracranial hypotension. METHODS Pituitary hormones were measured in a group of 42 consecutive patients with spontaneous intracranial hypotension. For patients with hyperprolactinemia, prolactin levels also were measured following treatment. Magnetic resonance imaging was performed prior to and following treatment. RESULTS The study group consisted of 27 women and 15 men with a mean age at onset of symptoms of 52.2 ± 10.7 years (mean ± SD; range 17-72 years). Hyperprolactinemia was detected in 10 patients (24%), ranging from 16 ng/ml to 96.6 ng/ml in men (normal range 3-14.7 ng/ml) and from 31.3 ng/ml to 102.5 ng/ml in women (normal range 3.8-23.2 ng/ml). In a multivariate analysis, only brain sagging on MRI was associated with hyperprolactinemia. Brain sagging was present in 60% of patients with hyperprolactinemia and in 19% of patients with normal prolactin levels (p = 0.02). Following successful treatment of the spontaneous intracranial hypotension, hyperprolactinemia resolved, along with normalization of brain MRI findings in all 10 patients. CONCLUSIONS Spontaneous intracranial hypotension is a previously undescribed cause of hyperprolactinemia. Brain sagging causing distortion of the pituitary stalk (stalk effect) may be responsible for the hyperprolactinemia.

  19. Adjustable Sample Holder With Pressure Contacts for Photoconductivity Measurement

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar

    2011-07-01

    Full Text Available A sample holder is designed to hold and apply pressure contacts on the electrodes of the photoconducting material to study the photoresponse transient. The sample holder is assembled on an aluminium base plate. The needle pointed probes are constrained to move under the spring action to provide the pressure contacts. One of the probes is provided with the facility of ± x directional movement to provide contacts on the samples having different spacing between the electrodes. The setup is simple in design and could find applications for the electrical measurements like dc conductivity and photoconductivity of semiconducting samples and can easily be assembled with scarp materials available in laboratories.

  20. Piston cylinder cell for high pressure ultrasonic pulse echo measurements

    Science.gov (United States)

    Kepa, M. W.; Ridley, C. J.; Kamenev, K. V.; Huxley, A. D.

    2016-08-01

    Ultrasonic techniques such as pulse echo, vibrating reed, or resonant ultrasound spectroscopy are powerful probes not only for studying elasticity but also for investigating electronic and magnetic properties. Here, we report on the design of a high pressure ultrasonic pulse echo apparatus, based on a piston cylinder cell, with a simplified electronic setup that operates with a single coaxial cable and requires sample lengths of mm only. The design allows simultaneous measurements of ultrasonic velocities and attenuation coefficients up to a pressure of 1.5 GPa. We illustrate the performance of the cell by probing the phase diagram of a single crystal of the ferromagnetic superconductor UGe2.

  1. Cryogenic tunnel measurement of total temperature and pressure

    Science.gov (United States)

    Ng, W.-F.; Rosson, J. C.

    1986-01-01

    A newly developed, 3-mm-diam, dual hot-wire aspirating probe was used to measure the time-resolved stagnation temperature and pressure in a transonic cryogenic wind tunnel. Measurements were taken in the freestream of the settling chamber and test section. Data were also obtained in the unsteady wake shed from an airfoil oscillating at 5 Hz. The investigation revealed the presence of large fluctuations in the settling chamber occuring at the blade passing frequency of the driving fan of the tunnel. These fluctuations decrease at the test section. The rms value of the fluctuating stagnation pressure decreased from 17.5 percent in the settling chamber to 3.7 percent in the test section. Fluctuating stagnation temperature decreased from 12.3 percent to 8.4 percent. Measurements in the wake of the oscillating airfoil showed a fluctuating stagnation temperature of as much as 42 K in rms value.

  2. Sound field separation with sound pressure and particle velocity measurements

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn; Leclère, Quentin

    2012-01-01

    separation techniques make it possible to distinguish between outgoing and incoming waves from the two sides, and thus NAH can be applied. In this paper, a separation method based on the measurement of the particle velocity in two layers and another method based on the measurement of the pressure...... and the velocity in a single layer are proposed. The two methods use an equivalent source formulation with separate transfer matrices for the outgoing and incoming waves, so that the sound from the two sides of the array can be modeled independently. A weighting scheme is proposed to account for the distance...... pressure-velocity method, although it requires an additional measurement surface. On the whole, the separation methods can be useful when the disturbance of the incoming field is significant. Otherwise the direct reconstruction is more accurate and straightforward. © 2012 Acoustical Society of America....

  3. Interpretation of Strain Measurements on Nuclear Pressure Vessels

    DEFF Research Database (Denmark)

    Andersen, Svend Ib Smidt; Engbæk, Preben

    1980-01-01

    Selected results from strain measurements on four nuclear pressure vessels are presented and discussed. The measurements were made in several different regions of the vessels: transition zones in vessel heads, flanges and bottom parts, nozzles, internal vessel structure and flange bolts. The resu......Selected results from strain measurements on four nuclear pressure vessels are presented and discussed. The measurements were made in several different regions of the vessels: transition zones in vessel heads, flanges and bottom parts, nozzles, internal vessel structure and flange bolts....... The results presented are based on data obtained by approximately 700 strain-gauges, and a comprehensive knowledge of the quality obtained by such measurements is established. It is shown that a thorough control procedure before and after the test as well as a detailed knowledge of the behaviour of the signal...... with a negligible zeroshift. However, deviations from linear behaviour are observed in several cases. This nonlinearity can be explained by friction (flange connections) or by gaps (concentrical nozzles) in certain regions, whereas local plastic deformations during the first pressure loadings of the vessel seem...

  4. Robust pressure sensor for measurements in boundary layers of liquid fluids with medium total pressures

    Science.gov (United States)

    Beutel, T.; Ferreira, N.; Leester-Schädel, M.; Büttgenbach, S.

    2011-06-01

    In this work, the latest results of the design, fabrication and characterization of a new MEMS piezoresistive pressure sensor are presented. It is made of silicon using a boron diffusion process to create piezoresistors. Significant changes in the layout as well as in the micro-fabrication process have been made, e.g. anodic bonding of a Pyrex cover on the backside. These lead to a very precise pressure sensor, which is tailor made for high dynamic measurements in fluids with a total pressure up to 4 bar. This new piezoresistive pressure sensor has been developed in order to meet the special requirements of measurements in fluid mechanics, particularly with regard to the non-intrusive nature of the sensor. The sensor development, starting with the simulation of mechanical stresses within the diaphragm is described. These calculations have lead to an optimized placement of the piezoresistors in order to achieve a maximum sensitivity. The result of this work is a sensor which has well known properties. Important parameters including sensitivity, resonance frequency and maximum load are described precisely. These are necessary to enable new measurements in the boundary layer of fluids. The experiments and the initial results, e.g. its linearity and its dynamic capability are demonstrated in several figures.

  5. 高岭土诱导大鼠脑积水模型的建立和监测%Kaolin- induced hydrocephalus in the rat: temporal sequence of changes in weight, intracranial pressure, ventriculomegaly and corpus callosum thickness

    Institute of Scientific and Technical Information of China (English)

    卫永旭; 王伟军; 宋菡姝; 靳世辉; 高瑞庭; 初明; 蔺友志

    2012-01-01

    Objective To develop models of kaolin - induced hydrocephalus in adult Wistar rats and to measure changes of body weight,intracranial pressure,ventriculomegaly and corpus callosum thickness.Methods 60 adult male Wistar rats were randomly divided into experimental group and control group.In the former group,40 rats were randomly separated into 5 subgroups:group A,B,C,D and E,then were used to construct animal models of hydrocephalus by injecting 0.1 ml volume of 25% kaolin sterile solution into the cisterna Magana with the aid of a surgical microscope.Controls were trcatcd in the same way with injection of saline.Body weighing,MRI and ICP were performed at the tine point of 3 days,1,2,4 and 8 weeks after kaolin injection,respectively.Corpus callosum thickness was measured at the level of the optic chiasm.Results Hydrocephalus was induced in 23 rats whose ventricular system expauded as times went on.In hydrocephalus rats,body weight was significantly lower than in age - matched saline - injected sham controls,ICP increased rapidly on day 3 post intracisternal kaolin injection,reached a maximum on day 7,remained markedly elevated through 8 week, and had reduced corpus callosum thickness as ventricle enlargment.Conclusions Kaolin injection through cistern magna can effectively eatablish a rat model of communicating hydrocephalus.Aherations in ICP,ventriculomegaly and corpus callosum thickness occurs sequentially,and the time - course of each manifestation of hydrocephalus differs.%目的 高岭土诱导Wistar大鼠脑积水后系统监测大鼠体质量、颅内压、脑室面积和胼胝体厚度的改变.方法 雄性Wistar大鼠60只,按随机数字表顺序分为实验组(n=40)和对照组(n=20).实验组40只大鼠再随机分为A、B、C、D、E五个亚组,向枕大池内注入25%无菌高岭土混悬液0.1 ml;对照组注入等量无菌生理盐水,注入后3d、1周、2周、4周和8周后行体质量、MRI检查及颅内压监测,经视交叉切

  6. Ambient-pressure thermodynamic measurements on UGe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, Frederic; Loehneysen, Hilbert von [Forschungszentrum Karlsruhe (Germany). Institut fuer Festkoerperphysik; Physikalisches Institut, Universitaet Karlsruhe (Germany); Meingast, Christoph [Forschungszentrum Karlsruhe (Germany). Institut fuer Festkoerperphysik; Flouquet, Jacques; Huxley, Andrew [SPSMS-DRFMC, CEA-Grenoble (France); Lashley, Jason [Materials Science Division and Technology Division, LANL, Los Alamos, New Mexico (United States); Fisher, Robert A.; Phillips, Norman E. [Materials Science Division, LBNL, Berkeley, California (United States)

    2008-07-01

    The pairing interaction leading to the formation of the Cooper pairs remains unidentified in the ferromagnetic superconductor UGe{sub 2}. Nevertheless, there is strong experimental evidence that superconductivity is not mediated by the magnetic fluctuations that drive T{sub Curie}(p) to zero; it rather appears closely related to another phase boundary T{sub x}(p) that occurs at lower pressure. Theoretical works suggested that this additional phase boundary could arise either from a coupling between SDW and CDW orderings or from a peak in the electronic density of states. Although the existence of this anomaly is experimentally incontestable between 0.6 and 1.2 GPa, the situation at ambient pressure remains ambiguous. We discuss the aforementioned scenarios in the light of recent high-resolution thermal expansion and calorimetric measurements realized under high magnetic fields at ambient pressure.

  7. Ambient-pressure thermodynamic measurements on UGe2

    Science.gov (United States)

    Hardy, F.; Meingast, C.; von Loehneysen, H.; Flouquet, J.; Huxley, A.; Lashley, J.; Fisher, R. A.; Phillips, N. E.

    2008-03-01

    The pairing interaction leading to the formation of the Cooper pairs remains unidentified in the ferromagnetic superconductor UGe2. Nevertheless, there is strong experimental evidence that superconductivity is not mediated by the magnetic fluctuations that drive TCurie (p) to zero; it rather appears closely related to another phase boundary Tx (p) that occurs at lower pressure. Theoretical works suggested that this additional phase boundary could arise either from a coupling between SDW and CDW orderings or from a peak in the electronic density of states. Although the existence of this anomaly is experimentally incontestable between 0.6 and 1.2 GPa, the situation at ambient pressure remains ambiguous. We discuss the aforementioned scenarios in the light of recent high-resolution thermal expansion and calorimetric measurements realized under high magnetic fields at ambient pressure.

  8. Natriuretic pro-peptides in idiopathic intracranial hypertension

    DEFF Research Database (Denmark)

    Skau, Maren Cecilie Kloppenbor; Gøtze, Jens Peter; Rehfeld, Jens F.;

    2010-01-01

    Idiopathic intracranial hypertension is a disorder of unknown pathogenesis. Natriuretic peptides may be involved in intracranial pressure regulation, but cerebrospinal fluid (CNS) and plasma concentrations in this disorder are unknown. We evaluated venous and intrathecal concentrations of ANP, BNP...... and CNP precursor peptides in 40 patients with idiopathic intracranial hypertension and in 20 controls. Natriuretic pro-peptides were quantitated using processing-independent assays. In CSF, no differences in peptide concentrations between patients and controls were found (proANP: 239 + or - 23 vs 231...

  9. Measurement of thermoelectric, galvanomagnetic, and thermomagnetic effects at ultrahigh pressure

    Science.gov (United States)

    Ovsyannikov, Sergey V.; Shchennikov, Vladimir V.

    2003-04-01

    Lead chalcogenides are successfully applied at sensors of infrared radiation, thermoelectrical devices, thermogenerator, photoresistances, photodiodes, lasers, tensometers etc. Under high pressures above 2.5 - 6 GPa lead chaclogenides are known to suffer phase transitions, but up to now the thermoelectric properties of these materials at high pressure were unknown. In recent papers it was shown that heterophase state of material, which is being forming in the vicinity of semiconductor-metal phase transformations may be considered as a model of layer fabricated systems. As the most properties being dependent on the concentration and configuration of phases inclusions these materials may be used in engineering. For example, semiconductor-metal phase transitions induced by nanosecond heating and cooling of small regions of the memory cell are known to be using for nonvolatile memory develop. Recently the new technique of thermomagnetic measurements allowing to test a micro-samples of semiconductors have been developed at high pressure up to 30 GPa. The technique was applied for determination of scattering mechanisms and mobilities of charge carriers of direct-gap semiconductors Te, Se at ultrahigh pressure up to 30 GPa. The above measurements seems to be perspective for implementation to microelectronic manufacturing and MEMS technologies, for example, in modeling, quality control or testing of integrated circuit (IC). In present paper the thermo- and galvanomagnetic properties of micro-samples ~ 200×200×20 mkm of lead chalcogenides (PbS, PbSe, PbTe) at high pressure are investigated. The data of transverse magnetoresistance (MR) and also transverse and longitudinal Nernst-Ettingshausen (N-E) effects of lead chalcogenides both for initial and new phases, and also for heterophase states in the vicinity of phase transformations at high pressure are presented. One may suppose that the effects observed will find an interesting applications in thermosense industry. The

  10. IIH with normal CSF pressures?

    Directory of Open Access Journals (Sweden)

    Soh Youn Suh

    2013-01-01

    Full Text Available Idiopathic intracranial hypertension (IIH is a condition of raised intracranial pressure (ICP in the absence of space occupying lesions. ICP is usually measured by lumbar puncture and a cerebrospinal fluid (CSF pressure above 250 mm H 2 O is one of the diagnostic criteria of IIH. Recently, we have encountered two patients who complained of headaches and exhibited disc swelling without an increased ICP. We prescribed acetazolamide and followed both patients frequently; because of the definite disc swelling with IIH related symptoms. Symptoms and signs resolved in both patients after they started taking acetazolamide. It is generally known that an elevated ICP, as measured by lumbar puncture, is the most important diagnostic sign of IIH. However, these cases caution even when CSF pressure is within the normal range, that suspicion should be raised when a patient has papilledema with related symptoms, since untreated papilledema may cause progressive and irreversible visual loss.

  11. Body mass index and blood pressure measurement during pregnancy.

    LENUS (Irish Health Repository)

    Hogan, Jennifer L

    2012-02-01

    OBJECTIVE: The accurate measurement of blood pressure requires the use of a large cuff in subjects with a high mid-arm circumference (MAC). This prospective study examined the need for a large cuff during pregnancy and its correlation with maternal obesity. METHODS: Maternal body mass index (BMI), fat mass, and MAC were measured. RESULTS: Of 179 women studied, 15.6% were obese. With a BMI of level 1 obesity, 44% needed a large cuff and with a BMI of level 2 obesity 100% needed a large cuff. CONCLUSION: All women booking for antenatal care should have their MAC measured to avoid the overdiagnosis of pregnancy hypertension.

  12. Biological characteristics of the cerebral venous system and its hemodynamic response to intracranial hypertension

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie; WANG Xi-ming; LUAN Li-ming; CHAO Bao-ting; PANG Bo; SONG Hui; PANG Qi

    2012-01-01

    Background The role of the cerebral venous system (CVS) in intracranial pressure (ICP) regulation remains largely unclear.In the present study,the interaction between ICP and the cerebral venous system and its possible mechanism were investigated with respect to the biological characteristics of the cerebral venous system and its hemodynamic response under increased ICP.@@Methods We created intracranial hypertension animal model,measured and calculated the venous flow velocity and diameter of the outflow terminal of the CVS with color ultrasonic system and recorded the vascular morphology by 3-dimensional anatomical microscopy.Patients who suffered from raised ICP underwent MRI and digital subtraction angiography (DSA) examination to show the length in the vertical direction of the wall of the bridging vein representing the diameter value.Pathological autopsy was performed from bodies of patients who had died from non-cerebral causes to observe the juncture part between the venous sinuses and tributary vertical brain veins.@@Results Under increased ICP conditions,venous drainage through the outlet cuff segment,a unique structure between the bridge vein and sinus,was obstructed and in turn venous blood became congested.Therefore,the increased blood volume worsened the pre-existing ICP according to the well-accepted theory regarding volume-pressure relationship.This phenomenon was described as concurrent “Venogenic intracranial hypertension”,which is characterized by intracranial venous blood stasis responsive to and together with the original increased ICP.@@Conclusions The existence of this special pathophysiological process is prevalent,rather than rare,in various intracranial disorders.This finding would definitely provide new insight into the area of cerebral venous system research.

  13. Intracranial blood flow measured with single photon emission computer tomography (SPECT) during transient -6 degrees head-down tilt.

    Science.gov (United States)

    Satake, H; Konishi, T; Kawashima, T; Matsunami, K; Uno, T; Imai, S; Yamada, H; Hirakawa, C

    1994-02-01

    Regional cerebral blood flow (CBF) during a transient head-down tilt of -6 degrees (-6 degrees HDT) was measured with single photon emission computer tomography (SPECT). CBF was measured and averaged for both sides of the brain areas; e.g., the bilateral anterior cerebral artery (bACA) area, the middle cerebral artery (bMCA) area, the posterior cerebral artery (bPCA) area, bilateral basal ganglia, and the cerebellum. Among these areas, a significant increase in CBF was observed in the basal ganglia and the cerebellum during -6 degrees HDT compared to pre-HDT. When CBF was measured separately in the left or right brain area, these significances disappeared, although a trend of increase or decrease was still observable. A trend of increase was observed in the left anterior cerebral artery (IACA) area, the right middle cerebral artery (rMCA) area, the right posterior cerebral artery (rPCA) area, the left and right basal ganglia, and the cerebellum. In rACA, IMCA and IPCA areas, a slight decrease in CBF was observed. At the same time, cardiac parameters were measured. Heart rate (HR), stroke volume (SV) and cardiac output (CO) did not change significantly, although SV slightly increased and HR slightly decreased during -6 degrees HDT.

  14. Pressure measurements on a pitching airfoil in a water channel

    Science.gov (United States)

    Conger, Rand N.; Ramaprian, B. R.

    1994-01-01

    Measurements of unsteady pressures over a symmetric NACA 0015 airfoil performing pitching maneuvers are reported. The tests were performed in an open-surface water channel specially constructed for this purpose. The design of the apparatus allowed the pressure measurements to be made to a very high degree of spatial and temporal resolution. Reynolds numbers in the range of 5.2 x 10(exp 4) to 2.2 x 10(exp 5) were studied. Although the results qualitatively agreed with earlier studies performed at similar Reynolds numbers, the magnitudes of pressure and aerodynamic forces measured were observed to be much larger than those measured in ealier pitchup studies. They were found, in fact, to be closer to those obtained in some recent high-Reynolds-number experiments. This interesting behavior, which was suspected to be caused by the relatively high freestream turbulence level in the water channel, was explored in some detail. In addition, several issues like the quasisteady and dynamic effects of the pitching process are discussed. The experimental data are all archived and are available for use as a database.

  15. The measured temperature and pressure of EDC37 detonation products

    Science.gov (United States)

    Ferguson, J. W.; Richley, J. C.; Sutton, B. D.; Price, E.; Ota, T. A.

    2017-01-01

    We present the experimentally determined temperature and pressure of the detonation products of EDC37; a HMX based conventional high explosive. These measurements were performed on a series of cylinder tests. The temperature measurements were undertaken at the end of the cylinder with optical fibres observing the bare explosive through a LiF window. The temperature of the products was measured for approximately 2 µs using single colour pyrometry, multicolour pyrometry and also using time integrated optical emission spectroscopy with the results from all three methods being broadly consistent. The peak temperature was found to be ≈ 3600 K dropping to ≈ 2400 K at the end of the measurement window. The spectroscopy was time integrated and showed that the emission spectra can be approximated using a grey body curve between 520 - 800 nm with no emission or absorption lines being observed. The pressure was obtained using an analytical method which requires the velocity of the expanding cylinder wall and the velocity of detonation. The pressure drops from an initial CJ value of ≈ 38 GPa to ≈ 4 GPa after 2 µs.

  16. Surface Pressure Measurements of Atmospheric Tides Using Smartphones

    Science.gov (United States)

    Price, Colin; Maor, Ron

    2017-04-01

    Similar to the oceans, the atmosphere also has tides that are measured in variations of atmospheric pressure. However, unlike the gravitational tides in the oceans, the atmospheric tides are caused primarily in the troposphere and stratosphere when the atmosphere is periodically heated by the sun, due to tropospheric absorption by water vapor and stratospheric absorption by ozone. Due to the forcing being always on the day side of the globe, the tides migrate around the globe following the sun (migrating tides) with a dominant periodicity of 12 hours (and less so at 24 hours). In recent years smartphones have been equipped with sensitive, cheap and reliable pressure sensors that can easily detect these atmospheric tides. By 2020 it is expected that there will be more than 6 billion smartphones globally, each measuring continuously atmospheric pressure at 1Hz temporal resolution. In this presentation we will present some control experiments we have performed with smartphones to monitor atmospheric tides, while also using random pressure data from more than 50,000 daily users via the WeatherSignal application. We conclude that smartphones are a useful tool for studying atmospheric tides on local and global scales.

  17. 高血压脑出血无创颅内压及脑灌注压监测临床研究%Monitoring noninvasive intracranial pressure and cerebral perfusion pressure in treatment of patients with hypertensive intracerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    张文德; 张湘; 邹志浩; 吴勤奋; 殷捷; 王建江; 郑玺; 莫拉丁

    2012-01-01

    Objective To evaluate clinical significance of monitoring noninvasive intracranial pressure (NICP) and cerebral perfusion pressure (CPP) in treatment of patients with hypertensive intracerebral hemorrhage. Methods This clinical randomized controlled trial enrolled 120 patients with hypertensive intracerebral hemorrhage who had sought medical treatment in our department from June 2008 through May 2010. They were randomized equally into a monitoring group where NICP and CPP were continuously monitored before and after operation and a non-monitoring group where no monitoring of NICP and CPP was performed. Results In the monitoring group,increased NICP and decreased CPP were shown in 50 patients and only 10 patients were shown with normal NICP (<26.6mmHg) and CPP (> 124.3 mm Hg). The abnormal NICP and CPP continuously monitored were treated with specific interventions like further operation or medication. In the non-monitoring group,patients received only conventional treatments.According to the Glasgow Outcome Scale (GOS), 31 patients (51.7%) had good recovery,20 (33.3%) were moderately disabled,5 (8.3%) severely disabled and 4 (6.7%) dead in the monitoring group while 23 (38.3%) patients had good recovery,18 (30.0%)were moderately disabled,10 (16.7%) severely disabled and 9 (15.0%) dead in the non-monitoring group.The outcomes of the monitoring group were significantly better than those of the non-monitoring group (P<0.05). Conclusion Continuous monitoring of NICP and CPP before and after operation should be performed in the treatment of patients with hypertensive intracerebral hemorrhage because it is helpful for clinical medication and reducing complications and mortality as well.%目的 探讨高血压脑出血手术前后监测无创颅内压(NICP)、脑灌注压(CPP)变化的临床意义. 方法 收集解放军第474医院神经外科自2008年6月至2010年5月收治的120例高血压脑出血手术患者,按照随机数字表法分为

  18. Idiopathic intracranial hypertension: a possible association with ImatinibIdiopathic intracranial hypertension: a possible association with Imatinib

    Directory of Open Access Journals (Sweden)

    Thomas Baumann

    2011-06-01

    Full Text Available Idiopathic intracranial hypertension (IIH is characterized by an increased intracranial pressure in the absence of a tumor and in the absence of a venous thrombosis. Associated risk factors include obesity and several medications such as tetracyclines. We report a 60-year-old patient who developed IIH under treatment with imatinib. To our knowledge such a possible connection has not been reported in the literature, even though intracranial hypertension is now listed as a rare possible side effect of treatment with imatinib in the Swiss List of Medications Arzneimittelkompendium. It remains to be seen, if further case reports will support this observation.

  19. Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension

    OpenAIRE

    Hutchinson, Peter J.; Kolias, Angelos G.; Timofeev, Ivan S.; Elizabeth A. Corteen; Czosnyka, Marek; Timothy, Jake; Anderson, Ian; Bulters, Diederik O.; Belli, Antonio; Eynon, C. Andrew; Wadley, John; Mendelow, A David; Mitchell, Patrick M; Wilson, Mark H; Critchley, Giles

    2016-01-01

    This is the author accepted manuscript. The final version is available from the Massachusetts Medical Society via http://dx.doi.org/10.1056/NEJMoa1605215 BACKGROUND The effect of decompressive craniectomy on clinical outcomes in patients with refractory traumatic intracranial hypertension remains unclear. METHODS From 2004 through 2014, we randomly assigned 408 patients, 10 to 65 years of age, with traumatic brain injury and refractory elevated intracranial pressure (>25 mm Hg) to und...

  20. Hyperventilation Therapy for Control of Posttraumatic Intracranial Hypertension

    Directory of Open Access Journals (Sweden)

    Daniel Agustín Godoy

    2017-07-01

    Full Text Available During traumatic brain injury, intracranial hypertension (ICH can become a life-threatening condition if it is not managed quickly and adequately. Physicians use therapeutic hyperventilation to reduce elevated intracranial pressure (ICP by manipulating autoregulatory functions connected to cerebrovascular CO2 reactivity. Inducing hypocapnia via hyperventilation reduces the partial pressure of arterial carbon dioxide (PaCO2, which incites vasoconstriction in the cerebral resistance arterioles. This constriction decrease cerebral blood flow, which reduces cerebral blood volume and, ultimately, decreases the patient’s ICP. The effects of therapeutic hyperventilation (HV are transient, but the risks accompanying these changes in cerebral and systemic physiology must be carefully considered before the treatment can be deemed advisable. The most prominent criticism of this approach is the cited possibility of developing cerebral ischemia and tissue hypoxia. While it is true that certain measures, such as cerebral oxygenation monitoring, are needed to mitigate these dangerous conditions, using available evidence of potential poor outcomes associated with HV as justification to dismiss the implementation of therapeutic HV is debatable and remains a controversial subject among physicians. This review highlights various issues surrounding the use of HV as a means of controlling posttraumatic ICH, including indications for treatment, potential risks, and benefits, and a discussion of what techniques can be implemented to avoid adverse complications.

  1. Skin perfusion pressure on the legs measured as the external pressure required for skin reddening after blanching

    DEFF Research Database (Denmark)

    Holstein, P; Nielsen, P.E.; Lund, P

    1980-01-01

    Hg (SD 8.7). As compared to the intra-arterial blood pressure the BTEP was found to lie close to the mean blood pressure in normal subjects as well as in hypertensive subjects. The present data indicate that the skin perfusion pressure on the legs can be measured by the rapid photo-electric technique......The skin perfusion on the calf was measured photo-electrically and by isotope washout technique using external counter pressure by a blood pressure cuff. By the photocell the skin blanching threshold external pressure (BTEP) was recorded on histamine flared red skin. By isotope washout technique...... the skin blood flow cessation external pressure (FCEP) was recorded using intra-dermal [131I-]-antipyrine mixed with histamine in estimating the skin blood flow. The external pressure was measured with an airfilled plastic cushion connected to a mercury manometer. Over a wide range of pressures as obtained...

  2. 吡拉西坦和甘露醇治疗颅内肿瘤术后颅内压增高的临床观察%Clinical observation of mannitol and piracetam in the treatment of patients with high intracranial pressure after intracranial tumor surgery

    Institute of Scientific and Technical Information of China (English)

    王骏飞; 柴慈婧; 李罡; 苏治国

    2012-01-01

    目的 探讨吡拉西坦和甘露醇治疗颅内肿瘤术后颅内压增高的疗效及安全性.方法 应用随机数字表法将2009年12月至201 1年12月在天津市第五中心医院神经外科住院治疗的102例颅内肿瘤术后颅内压增高患者分为对照组(51例)和观察组(51例),对照组患者给予20%甘露醇进行治疗,观察组患者给予吡拉西坦注射液进行治疗,其他治疗措施相同,比较对照组与观察组患者临床疗效和不良反应发生情况.结果 观察组患者的治疗总有效率(96.1%)明显高于对照组(84.3%),且对照组与观察组患者在不良反应发生率方面差异无统计学意义(P>0.05).结论 吡拉西坦注射液治疗颅内肿瘤术后颅内压增高疗效确切,能够代替甘露醇用于颅内肿瘤术后颅内压增高患者降颅压治疗,明显提高临床疗效,且不良反应少,值得进一步推广.%Objective To investigate the clinical efficacy and safety of patients with high intraera-mal pressure after intracranial tumor surgery to provide reference for a safe and effective treatment on it Methods We collected clinical data of 102 cases of patients who were treated in the department of neuro-surgery in our hospital from December 2009 to December 2011. These patients were divided into the control group and observation group by using a random number table, patients in the control group was given 20% Mannitol, but patients in the observation group was given 20% Piracetam injection, the clinical efficacy and adverse reaction of patients in the control group and the observation group was evaluated. Results The total efficient rate was higher in the observation group than that in the control group (96. 1% vs 84. 3% , P 0. 05). Conclusions Piracetam injection in the treatment gf intracranial tumor postoperative intracranial hypertension curative effect, and it is safe, reliabie and worthy of clinical application.

  3. Pre-measurement rest time affects magnitude and reliability of toe pressure measurements.

    Science.gov (United States)

    Chuter, Vivienne Helaine; Casey, Sarah Louise

    2015-06-01

    Toe pressures are used to evaluate lower extremity healing capacity and screen for peripheral arterial disease (PAD). Although toe pressures are commonly used clinically both as an independent measure and in the calculation of the toe-brachial index, the effect of pre-measurement rest duration on the magnitude and reliability of toe pressures is unknown. This study investigated the effect of pre-measurement rest duration on toe pressures. Seventy community-based participants meeting guidelines for PAD screening were recruited. Systolic toe pressures either at the left or right hallux were manually measured using photoplethysmography following 5, 10 and 15 min of rest in a supine horizontal position. Testing was repeated 7-10 days later. A significant drop in toe pressure (3.86 mmHg) occurred between 5 and 10 min (p = 0.001). No significant change occurred between 10 and 15 min. Reliability after 5 min was excellent (intra-class correlation coefficient, ICC = 0.80, 95% CI 0.68-0.89), increasing slightly at 10 and 15 min (ICC = 0.86, 95% CI 0.77-0.92 and ICC = 0.82, 95% CI 0.69-0.89). Toe pressures stabilize after 10 min of rest in a supine horizontal position. Longer periods of pre-measurement rest did not improve reliability significantly.

  4. Indications for portal pressure measurement in chronic liver disease

    DEFF Research Database (Denmark)

    Hobolth, Lise; Bendtsen, Flemming; Møller, Søren

    2012-01-01

    Portal hypertension leads to development of serious complications such as esophageal varices, ascites, renal and cardiovascular dysfunction. The importance of the degree of portal hypertension has been substantiated within recent years. Measurement of the portal pressure is simple and safe...... of HVPG should therefore be considered as a part of the general characterization of patients with portal hypertension in departments assessing and treating this condition....

  5. Measurements and modeling of VLLE at elevated pressures

    DEFF Research Database (Denmark)

    Laursen, Torben

    and pure component calibration. Samples from the different liquid phases in the high-pressure cell is taken using a moveable needle. The systems investigated have been a combination of the components: CO2, N2, di-methyl ether (DME), water, methanol, ethanol and 1-propanol. 41 isotherms have been measured...... containing CO2, while the model has some problems with systems containing N2....

  6. Quality of blood pressure measurement in community health centres.

    Science.gov (United States)

    Sandoya-Olivera, Edgardo; Ferreira-Umpiérrez, Augusto; Machado-González, Federico

    To determine the quality of the blood pressure measurements performed during routine care in community health centres. An observational, cross-sectional study was conducted in 5 private and public health centres in Maldonado, Uruguay, in July-August 2015. The observations were made during the measurements performed by health personnel, using the requirements established by the American Heart Association. An analysis was made on 36 variables that were grouped in categories related to environment, equipment, interrogation, patient, and observer. Statistical analysis was performed using Chi(2) test or Fisher test. Statistical significance was considered to be less than 5% (p<.05). The measurements were made by a registered nurse or nurse in 71% of cases, physician in 20%, and student nurse in 9%. An aneroid sphygmomanometer was used in 89%, and mercury 11%. Satisfactory results were found in variables related to environment (93%), equipment (99%), and patient attitude (82%), and intermediate in the attitudes of the operator (64%), and poor in relation to the interrogation (18%), with the mean of correct variables per measurement being 69%. The main flaws in the procedure were the operator. The measurement of blood pressure is a manoeuvre that healthcare professionals perform thousands of times a year. If the measurement is used for the diagnosis and/or chronic management of arterial hypertension, not systematically applying the established recommendations leads to an inappropriate care of a very significant number of patients. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  7. Measurement of viscosity of gaseous mixtures at atmospheric pressure

    Science.gov (United States)

    Singh, J. J.; Mall, G. H.; Chegini, H.

    1986-01-01

    Coefficients of viscosity of various types of gas mixtures, including simulated natural-gas samples, have been measured at atmospheric pressure and room temperature using a modified capillary tube method. Pressure drops across the straight capillary tube section of a thermal mass flowmeter were measured for small, well-defined, volume flow rates for the test gases and for standard air. In this configuration, the flowmeter provides the volumetric flow rates as well as a well-characterized capillary section for differential pressure measurements across it. The coefficients of viscosity of the test gases were calculated using the reported value of 185.6 micro P for the viscosity of air. The coefficients of viscosity for the test mixtures were also calculated using Wilke's approximation of the Chapman-Enskog (C-E) theory. The experimental and calculated values for binary mixtures are in agreement within the reported accuracy of Wilke's approximation of the C-E theory. However, the agreement for multicomponent mixtures is less satisfactory, possible because of the limitations of Wilkes's approximation of the classical dilute-gas state model.

  8. Accuracy of the Omron RX-M, an automated blood pressure measuring device, measuring blood pressure at the wrist, according to a modified British Hypertension Society protocol.

    NARCIS (Netherlands)

    Braam, R.L.; Aslan, B.; Thien, Th.

    2004-01-01

    OBJECTIVE: To determine the accuracy of the Omron RX-M, a device measuring blood pressure oscillometrically at the wrist. METHODS: In 89 subjects (mean age 55+/-14 years) blood pressure measurements at the wrist with the Omron RX-M were compared to sequential blood pressure measurements with a

  9. Idiopathic intracranial hypertension and transverse sinus stenoses

    DEFF Research Database (Denmark)

    Skyrman, Simon; Fytagoridis, Anders; Andresen, Morten

    2013-01-01

    An 18-year-old woman was diagnosed with idiopathic intracranial hypertension (IIH) and bilateral transverse sinus stenoses (TSS), after presenting with papilledema and decreased visual acuity. Lumbar puncture revealed an opening pressure of >60 cm H2O. MRI showed bilateral TSS believed to be asso......An 18-year-old woman was diagnosed with idiopathic intracranial hypertension (IIH) and bilateral transverse sinus stenoses (TSS), after presenting with papilledema and decreased visual acuity. Lumbar puncture revealed an opening pressure of >60 cm H2O. MRI showed bilateral TSS believed...... to be associated with the IIH. Initial treatment consisted of symptom relief by a temporary lumbar drain for cerebrospinal fluid (CSF) diversion, while the pros and cons of a more permanent solution by insertion of a ventriculoperitoneal shunt (VPS) or bilateral transverse sinus stent was discussed. A VPS...

  10. Variation in monitoring and treatment policies for intracranial hypertension in traumatic brain injury: A survey in 66 neurotrauma centers participating in the CENTER-TBI study

    NARCIS (Netherlands)

    M.C. Cnossen (Maryse); Huijben, J.A. (Jilske A.); van der Jagt, M. (Mathieu); Volovici, V. (Victor); van Essen, T. (Thomas); S. Polinder (Suzanne); D. Nelson (David); Ercole, A. (Ari); Stocchetti, N. (Nino); Citerio, G. (Giuseppe); W.C. Peul (Wilco); A.I.R. Maas (Andrew I.R.); D.K. Menon (David ); E.W. Steyerberg (Ewout W.); Lingsma, H.F. (Hester F.); Adams, H. (Hadie); Alessandro, M. (Masala); J. Allanson (Judith); Amrein, K. (Krisztina); Andaluz, N. (Norberto); N. Andelic (Nada); Andrea, N. (Nanni); L. Andreassen (Lasse); Anke, A. (Audny); Antoni, A. (Anna); Ardon, H. (Hilko); Audibert, G. (Gérard); Auslands, K. (Kaspars); Azouvi, P. (Philippe); Baciu, C. (Camelia); Bacon, A. (Andrew); Badenes, R. (Rafael); Baglin, T. (Trevor); R.H.M.A. Bartels (Ronald); P. Barzo (P.); Bauerfeind, U. (Ursula); R. Beer (Ronny); Belda, F.J. (Francisco Javier); B.-M. Bellander (Bo-Michael); A. Belli (Antonio); Bellier, R. (Rémy); H. Benali (Habib); Benard, T. (Thierry); M. Berardino (Maurizio); L. Beretta (Luigi); Beynon, C. (Christopher); Bilotta, F. (Federico); H. Binder (Harald); Biqiri, E. (Erta); Blaabjerg, M. (Morten); Lund, S.B. (Stine Borgen); Bouzat, P. (Pierre); Bragge, P. (Peter); Brazinova, A. (Alexandra); F. Brehar (Felix); Brorsson, C. (Camilla); Buki, A. (Andras); M. Bullinger (Monika); Bucková, V. (Veronika); Calappi, E. (Emiliana); P. Cameron (Peter); Carbayo, L.G. (Lozano Guillermo); Carise, E. (Elsa); K.L.H. Carpenter (Keri L.H.); Castaño-León, A.M. (Ana M.); Causin, F. (Francesco); Chevallard, G. (Giorgio); A. Chieregato (Arturo); G. Citerio (Giuseppe); Cnossen, M. (Maryse); M. Coburn (Mark); J.P. Coles (Jonathan P.); Cooper, J.D. (Jamie D.); Correia, M. (Marta); A. Covic (Amra); N. Curry (Nicola); E. Czeiter (Endre); M. Czosnyka (Marek); Dahyot-Fizelier, C. (Claire); F. Damas (François); P. Damas (Pierre); H. Dawes (Helen); De Keyser, V. (Véronique); F.D. Corte (Francesco); B. Depreitere (Bart); Ding, S. (Shenghao); D.W.J. Dippel (Diederik); K. Dizdarevic (Kemal); Dulière, G.-L. (Guy-Loup); Dzeko, A. (Adelaida); G. Eapen (George); Engemann, H. (Heiko); A. Ercole (Ari); P. Esser (Patrick); Ezer, E. (Erzsébet); M. Fabricius (Martin); V.L. Feigin (V.); Feng, J. (Junfeng); Foks, K. (Kelly); F. Fossi (Francesca); Francony, G. (Gilles); J. Frantzén (Janek); Freo, U. (Ulderico); S.K. Frisvold (Shirin Kordasti); Furmanov, A. (Alex); Gagliardo, P. (Pablo); D. Galanaud (Damien); G. Gao (Guoyi); K. Geleijns (Karin); A. Ghuysen (Alexandre); Giraud, B. (Benoit); Glocker, B. (Ben); Gomez, P.A. (Pedro A.); Grossi, F. (Francesca); R.L. Gruen (Russell); Gupta, D. (Deepak); J.A. Haagsma (Juanita); E. Hadzic (Ermin); I. Haitsma (Iain); J.A. Hartings (Jed); R. Helbok (Raimund); E. Helseth (Eirik); Hertle, D. (Daniel); S. Hill (Sean); Hoedemaekers, A. (Astrid); S. Hoefer (Stefan); P.J. Hutchinson (Peter J.); Håberg, K.A. (Kristine Asta); B.C. Jacobs (Bart); Janciak, I. (Ivan); K. Janssens (Koen); Jiang, J.-Y. (Ji-Yao); Jones, K. (Kelly); Kalala, J.-P. (Jean-Pierre); Kamnitsas, K. (Konstantinos); Karan, M. (Mladen); Karau, J. (Jana); A. Katila (Ari); M. Kaukonen (Maija); Keeling, D. (David); Kerforne, T. (Thomas); N. Ketharanathan (Naomi); Kettunen, J. (Johannes); Kivisaari, R. (Riku); A.G. Kolias (Angelos G.); Kolumbán, B. (Bálint); E.J.O. Kompanje (Erwin); D. Kondziella (Daniel); L.-O. Koskinen (Lars-Owe); Kovács, N. (Noémi); F. Kalovits (Ferenc); A. Lagares (Alfonso); L. Lanyon (Linda); S. Laureys (Steven); Lauritzen, M. (Martin); F.E. Lecky (Fiona); C. Ledig (Christian); R. Lefering; V. Legrand (Valerie); Lei, J. (Jin); L. Levi (Leon); R. Lightfoot (Roger); H.F. Lingsma (Hester); D. Loeckx (Dirk); Lozano, A. (Angels); Luddington, R. (Roger); Luijten-Arts, C. (Chantal); Maas, A.I.R. (Andrew I.R.); MacDonald, S. (Stephen); MacFayden, C. (Charles); M. Maegele; M. Majdan (Marek); Major, S. (Sebastian); A. Manara (Alex); Manhes, P. (Pauline); G. Manley (Geoffrey); Martin, D. (Didier); C. Martino (Costanza); Maruenda, A. (Armando); H. Maréchal (Hugues); Mastelova, D. (Dagmara); Mattern, J. (Julia); McMahon, C. (Catherine); Melegh, B. (Béla); Menon, D. (David); T. Menovsky (Tomas); Morganti-Kossmann, C. (Cristina); Mulazzi, D. (Davide); Mutschler, M. (Manuel); H. Mühlan (Holger); Negru, A. (Ancuta); Nelson, D. (David); E. Neugebauer (Eddy); V.F. Newcombe (Virginia F.); Noirhomme, Q. (Quentin); Nyirádi, J. (József); M. Oddo (Mauro); A.W. Oldenbeuving; M. Oresic (Matej); Ortolano, F. (Fabrizio); A. Palotie (Aarno); P.M. Parizel; Patruno, A. (Adriana); J.-F. Payen (Jean-François); Perera, N. (Natascha); V. Perlbarg (Vincent); Persona, P. (Paolo); Peul, W. (Wilco); N. Pichon (Nicolas); Piilgaard, H. (Henning); A. Piippo (Anna); S.P. Floury (Sébastien Pili); M. Pirinen (Matti); H. Ples (Horia); Polinder, S. (Suzanne); Pomposo, I. (Inigo); M. Psota (Marek); P. Pullens (Pim); L. Puybasset (Louis); A. Ragauskas (Arminas); R. Raj (Rahul); Rambadagalla, M. (Malinka); Rehorcíková, V. (Veronika); J.K.J. Rhodes (Jonathan K.J.); S. Richardson (Sylvia); S. Ripatti (Samuli); S. Rocka (Saulius); Rodier, N. (Nicolas); Roe, C. (Cecilie); Roise, O. (Olav); G. Roks (Gerwin); Romegoux, P. (Pauline); J. Rosand (Jonathan); Rosenfeld, J. (Jeffrey); C. Rosenlund (Christina); G. Rosenthal (Guy); R. Rossaint (Rolf); S. Rossi (Sandra); Rostalski, T. (Tim); D. Rueckert (Daniel); de Ruiz, A.F. (Arcaute Felix); M. Rusnák (Martin); Sacchi, M. (Marco); Sahakian, B. (Barbara); J. Sahuquillo (Juan); O. Sakowitz (Oliver); Sala, F. (Francesca); Sanchez-Pena, P. (Paola); Sanchez-Porras, R. (Renan); Sandor, J. (Janos); Santos, E. (Edgar); N. Sasse (Nadine); Sasu, L. (Luminita); Savo, D. (Davide); I.B. Schipper (Inger); Schlößer, B. (Barbara); S. Schmidt (Silke); Schneider, A. (Annette); H. Schoechl (Herbert); G.G. Schoonman; Rico, F.S. (Frederik Schou); E. Schwendenwein (Elisabeth); Schöll, M. (Michael); Sir, O. (özcan); T. Skandsen (Toril); Smakman, L. (Lidwien); D. Smeets (Dominique); Smielewski, P. (Peter); Sorinola, A. (Abayomi); E. Stamatakis (Emmanuel); S. Stanworth (Simon); Stegemann, K. (Katrin); Steinbüchel, N. (Nicole); R. Stevens (Robert); W. Stewart (William); E.W. Steyerberg (Ewout); N. Stocchetti (Nino); Sundström, N. (Nina); Synnot, A. (Anneliese); J. Szabó (József); J. Söderberg (Jeannette); F.S. Taccone (Fabio); Tamás, V. (Viktória); Tanskanen, P. (Päivi); A. Tascu (Alexandru); Taylor, M.S. (Mark Steven); Te, A.B. (Ao Braden); O. Tenovuo (Olli); Teodorani, G. (Guido); A. Theadom (Alice); Thomas, M. (Matt); D. Tibboel (Dick); C.M. Tolias (Christos M.); Tshibanda, J.-F.L. (Jean-Flory Luaba); Tudora, C.M. (Cristina Maria); P. Vajkoczy (Peter); Valeinis, E. (Egils); Hecke, W.V. (Wim Van); Praag, D.V. (Dominique Van); Dirk, V.R. (Van Roost); Vlierberghe, E.V. (Eline Van); Vyvere, T.V. (Thijs vande); Vanhaudenhuyse, A. (Audrey); A. Vargiolu (Alessia); E. Vega (Emmanuel); J. Verheyden (Jan); Vespa, P.M. (Paul M.); A. Vik (Anne); R. Vilcinis (Rimantas); Vizzino, G. (Giacinta); C.L.A.M. Vleggeert-Lankamp (Carmen); V. Volovici (Victor); P. Vulekovic (Peter); Vámos, Z. (Zoltán); Wade, D. (Derick); Wang, K.K.W. (Kevin K.W.); Wang, L. (Lei); E.D. Wildschut (Enno); G. Williams (Guy); Willumsen, L. (Lisette); Wilson, A. (Adam); Wilson, L. (Lindsay); Winkler, M.K.L. (Maren K.L.); P. Ylén (Peter); Younsi, A. (Alexander); M. Zaaroor (Menashe); Zhang, Z. (Zhiqun); Zheng, Z. (Zelong); Zumbo, F. (Fabrizio); de Lange, S. (Stefanie); G.C.W. De Ruiter (Godard C.W.); den Boogert, H. (Hugo); van Dijck, J. (Jeroen); T.A. van Essen (T.); C.M. van Heugten (Caroline M.); M. van der Jagt (Mathieu); J. van der Naalt (Joukje)

    2017-01-01

    textabstractBackground: No definitive evidence exists on how intracranial hypertension should be treated in patients with traumatic brain injury (TBI). It is therefore likely that centers and practitioners individually balance potential benefits and risks of different intracranial pressure (ICP)

  11. Intracranial tuberculoma: MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, P.; Zenteno, M.A.; Rodriguez-Carbajal, J.; Brutto, O.H. del; Talamas, O.

    1989-09-01

    MR studies of 6 patients with intracranial tuberculoma are reviewed. All patients also underwent CT scans which showed hypo- or isodense lesions with abnormal enhancement following contrast administration. MR showed lesions with prolongation of the T1 relaxation time in every case. On the T2-weighted sequences, the signal properties of the tuberculoma varied according to the stage of evolution of the lesion. Incipient tuberculomas appeared as scattered areas of hypointensity surrounded by edema. Mature tuberculomas were composed of a dark necrotic center surrounded by an isointense capsule which was, in turn, surrounded by edema. In one patient, the center of the lesion was hyperintense probably because of liquefaction and pus formation (tuberculous abscess). While both, CT and MR, were equally sensitive in visualizing the intracranial tuberculoma in every patient, MR was slightly superior in demonstrating the extent of the lesion, especially for brainstem tuberculomas. Nevertheless, the potential role for MR diagnosis of intracranial tuberculoma is limited by the fact that other infectious or neoplasic diseases may present similar findings. The diagnosis of intracranial tuberculoma should rest on a proper integration of data from clinical manifestations, cerebrospinal fluid analysis, and neuroimaging studies. (orig.).

  12. Intracranial artery dissection

    NARCIS (Netherlands)

    Sikkema, T.; Uyttenboogaart, Maarten; Eshghi, O.; De Keyser, J.; Brouns, R.; van Dijk, J.M.C.; Luijckx, G. J.

    2014-01-01

    The aim of this narrative review is to evaluate the pathogenesis, clinical features, diagnosis, treatment and prognosis of intracranial artery dissection (IAD). IAD is a rare and often unrecognized cause of stroke or subarachnoid haemorrhage (SAH), especially in young adults. Two types of IAD can be

  13. Intracranial artery dissection

    NARCIS (Netherlands)

    Sikkema, T.; Uyttenboogaart, Maarten; Eshghi, O.; De Keyser, J.; Brouns, R.; van Dijk, J.M.C.; Luijckx, G. J.

    The aim of this narrative review is to evaluate the pathogenesis, clinical features, diagnosis, treatment and prognosis of intracranial artery dissection (IAD). IAD is a rare and often unrecognized cause of stroke or subarachnoid haemorrhage (SAH), especially in young adults. Two types of IAD can be

  14. Propagation of radiosonde pressure sensor errors to ozonesonde measurements

    Directory of Open Access Journals (Sweden)

    R. M. Stauffer

    2013-08-01

    Full Text Available Several previous studies highlight pressure (or equivalently, pressure altitude discrepancies between the radiosonde pressure sensor and that derived from a GPS flown with the radiosonde. The offsets vary during the ascent both in absolute and percent pressure differences. To investigate this, a total of 501 radiosonde/ozonesonde launches from the Southern Hemisphere subtropics to northern mid-latitudes are considered, with launches between 2006–2013 from both historical and campaign-based intensive stations. Three types of electrochemical concentration cell (ECC ozonesonde manufacturers (Science Pump Corporation; SPC and ENSCI/Droplet Measurement Technologies; DMT and five series of radiosondes from two manufacturers (International Met Systems: iMet, iMet-P, iMet-S, and Vaisala: RS80 and RS92 are analyzed to determine the magnitude of the pressure offset and the effects these offsets have on the calculation of ECC ozone (O3 mixing ratio profiles (O3MR from the ozonesonde-measured partial pressure. Approximately half of all offsets are > ±0.7 hPa in the free troposphere, with nearly a quarter > ±1.0 hPa at 26 km, where the 1.0 hPa error represents ~5% of the total atmospheric pressure. Pressure offsets have negligible effects on O3MR below 20 km (98% of launches lie within ±5% O3MR error at 20 km. Ozone mixing ratio errors in the 7–15 hPa layer (29–32 km, a region critical for detection of long-term O3 trends, can approach greater than ±10% (>25% of launches that reach 30 km exceed this threshold. Comparisons of total column O3 yield average differences of +1.6 DU (−1.1 to +4.9 DU 10th to 90th percentiles when the O3 is integrated to burst with addition of the McPeters and Labow (2012 above-burst O3 column climatology. Total column differences are reduced to an average of +0.1 DU (−1.1 to +2.2 DU when the O3 profile is integrated to 10 hPa with subsequent addition of the O3 climatology above 10 hPa. The RS92 radiosondes are clearly

  15. Pediatric intracranial primary anaplastic ganglioglioma.

    Science.gov (United States)

    Lüdemann, Wolf; Banan, Rouzbeh; Hartmann, Christian; Bertalanffy, Helmut; Di Rocco, Concezio

    2017-02-01

    Primary intracranial anaplastic gangliogliomas are rare tumors in the pediatric patient group. Most of them present with symptoms of elevated pressure or symptomatic epilepsy. Extraaxial location is far more common than axial location. On MRI examination, they mimic pilocytic astrocytomas. The outcome after surgery depends mainly on the possible amount of surgical resection, and oncological therapy is necessary to prevent recurrence of the disease. An 11-year-old boy presented with headache and double vision due to obstructive hydrocephalus. MRI of the brain revealed an axial partially contrast enhancing lesion in the quadrigeminal plate extending from the cerebellum to the pineal gland and causing hydrocephalus. Subtotal removal of the lesion was performed, and the diagnosis of an anaplastic ganglioglioma was established and confirmed by the reference center. At the latest follow up (3 months), the boy is without any neurological symptoms and scheduled for radiation therapy as well as chemotherapy.

  16. Idiopathic intracranial hypertension in female homozygous twins.

    OpenAIRE

    Fujiwara, S; Sawamura, Y; Kato, T.; Abe, H.; Katusima, H

    1997-01-01

    The authors report on female homozygous twins with idiopathic intracranial hypertension. At the age of 12 years, both twins simultaneously developed visual disturbances with photophobia. At the age of 19 years, an ophthalmological examination disclosed papilloedema in both their eyes. At the age of 22 years, a lumbar puncture showed raised CSF pressure over (200 mm H2O) in both twins. Their neurological and radiological examinations were extremely similar; both of them had severely impaired v...

  17. A user's guide to intra-abdominal pressure measurement.

    LENUS (Irish Health Repository)

    Sugrue, Michael

    2015-01-01

    The intra-abdominal pressure (IAP) measurement is a key to diagnosing and managing critically ill medical and surgical patients. There are an increasing number of techniques that allow us to measure the IAP at the bedside. This paper reviews these techniques. IAP should be measured at end-expiration, with the patient in the supine position and ensuring that there is no abdominal muscle activity. The intravesicular IAP measurement is convenient and considered the gold standard. The level where the mid-axillary line crosses the iliac crest is the recommended zero reference for the transvesicular IAP measurement; moreover, marking this level on the patient increases reproducibility. Protocols for IAP measurement should be developed for each ICU based on the locally available tools and equipment. IAP measurement techniques are safe, reproducible and accurate and do not increase the risk of urinary tract infection. Continuous IAP measurement may offer benefits in specific situations in the future. In conclusion, the IAP measurement is a reliable and essential adjunct to the management of patients at risk of intra-abdominal hypertension.

  18. Highlighting intracranial pressure monitoring in patients with severe acute brain trauma Ressaltando a monitorização da pressão intracraniana em pacientes com traumatismo cerebral agudo grave

    Directory of Open Access Journals (Sweden)

    Antonio L. E Falcão

    1995-09-01

    Full Text Available Intracranial pressure (ICP monitoring was carried out in 100 patients with severe acute brain trauma, primarily by means of a subarachnoid catheter. Statistical associations were evaluated between maximum ICP values and: 1 Glasgow Coma Scale (GCS scores; 2 findings on computed tomography (CT scans of the head; and 3 mortality. A significant association was found between low GCS scores (3 to 5 and high ICP levels, as well as between focal lesions on CT scans and elevated ICP. Mortality was significantly higher in patients with ICP > 40 mm Hg than in those with ICP Monitorização da pressão intracraniana (PIC foi adotada em 100 pacientes com traumatismo cerebral agudo grave, usando-se preferencialmente um catéter subaracnóide. Associações estatísticas foram avaliadas entre valores máximos de PIC e : 1 número de pontos na Escala de Coma de Glasgow (ECG; 2 achados na tomografia computadorizada (TC da cabeça; e 3 mortalidade. Encontrou-se associação significante entre baixo número de pontos (3 a 5 na ECG e PIC elevada, assim como entre lesões focais na TC e hipertensão intracraniana. A mortalidade foi significantemente maior em pacientes com PIC > 40 mm Hg do que naqueles com PIC < 20 mm Hg.

  19. MR diffusion imaging of human intracranial tumours

    DEFF Research Database (Denmark)

    Krabbe, K; Gideon, P; Wagn, P;

    1997-01-01

    We used MRI for in vivo measurement of brain water self-diffusion in patients with intracranial tumours. The study included 28 patients (12 with high-grade and 3 with low-grade gliomas, 7 with metastases, 5 with meningiomas and 1 with a cerebral abscess). Apparent diffusion coefficients (ADC) wer...

  20. Measurement of cricoid pressure force during simulated Sellick's manoeuvre.

    Science.gov (United States)

    Andruszkiewicz, Paweł; Zawadka, Mateusz; Kosińska, Anna; Walczak-Wieteska, Paulina; Majerowicz, Kalina

    2017-09-27

    Cricoid pressure is a standard anaesthetic procedure used to reduce the risk of aspiration of gastric contents during the induction of general anaesthesia. However, for several years its validity has been questioned. There still remains the question of whether we perform it correctly. The aim of the study was an evaluation of the theoretical knowledge of Sellick's manoeuvre, as well an assessment of practical skill related with it when simulated on a model of the upper airway. The study was performed on a cohort of anaesthetists and anaesthetic nurses working in various hospitals in the Warsaw area. Measurements were taken on an upper airway model placed on an electronic kitchen scale. Participants were asked to perform Sellick's manoeuvre in the way they do it in their clinical practice. The test was done twice. Both the position and pressures applied on the model were documented. Knowledge concerning current recommendations of cricoid force was noted. 206 subjects participated in the study. Only 49% (n = 101) properly identified cricoid cartilage during their application of Sellick's manoeuvre. Application of the correct pressure on the model of the airway was noted in 16.5% (n = 34) during the first attempt and in 20.4% (n = 42) during the second attempt. The median force applied during simulated Sellick's manoeuvrewas 36 N (IQR: 26-55) in the first attempt, and 38 (IQR 25-55) in the second attempt. Sellick's manoeuvre was performed incorrectly in many cases. Half of the participants of our study applied the pressure in the wrong place while the majority of them used an inappropriate amount of force. Thus, the application of cricoid pressure in patients should be preceded with simulation training.

  1. A batch fabricated capacitive pressure sensor with an integrated Guyton capsule for interstitial fluid pressure measurement

    Science.gov (United States)

    Maleki, Teimour; Fogle, Benjamin; Ziaie, Babak

    2011-05-01

    In this paper, we present the design, fabrication and test of a batch fabricated capacitive pressure sensor with an integrated Guyton capsule for interstitial fluid pressure measurement. The sensor is composed of 12 µm thick single crystalline silicon membrane and a 3 µm gap, hermetically sealed through silicon-glass anodic bonding. A novel batch scale method for creating electrical feed-throughs inside the sealed capacitor chamber is developed. The Guyton capsule consists of an array of 10 µm diameter access holes etched onto a silicon back-plate separated from the silicon sensing membrane by a gap of 5 µm. The presence of the Guyton capsule (i.e. plates with access holes plus the gap separating them from the sensing membrane) allows for the ingress of interstitial fluid inside the 5 µm gap following the implantation, thus, providing an accurate measurement of interstitial fluid pressure. The fabricated sensor is 3 × 2 × 0.42 mm3 in dimensions and has a maximum sensitivity of 10 fF mmHg-1.

  2. HIGH TEMPERATURE HIGH PRESSURE THERMODYNAMIC MEASUREMENTS FOR COAL MODEL COMPOUNDS

    Energy Technology Data Exchange (ETDEWEB)

    Vinayak N. Kabadi

    2000-05-01

    The flow VLE apparatus designed and built for a previous project was upgraded and recalibrated for data measurements for this project. The modifications include better and more accurate sampling technique, addition of a digital recorder to monitor temperature and pressure inside the VLE cell, and a new technique for remote sensing of the liquid level in the cell. VLE data measurements for three binary systems, tetralin-quinoline, benzene--ethylbenzene and ethylbenzene--quinoline, have been completed. The temperature ranges of data measurements were 325 C to 370 C for the first system, 180 C to 300 C for the second system, and 225 C to 380 C for the third system. The smoothed data were found to be fairly well behaved when subjected to thermodynamic consistency tests. SETARAM C-80 calorimeter was used for incremental enthalpy and heat capacity measurements for benzene--ethylbenzene binary liquid mixtures. Data were measured from 30 C to 285 C for liquid mixtures covering the entire composition range. An apparatus has been designed for simultaneous measurement of excess volume and incremental enthalpy of liquid mixtures at temperatures from 30 C to 300 C. The apparatus has been tested and is ready for data measurements. A flow apparatus for measurement of heat of mixing of liquid mixtures at high temperatures has also been designed, and is currently being tested and calibrated.

  3. Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension.

    Science.gov (United States)

    Hutchinson, Peter J; Kolias, Angelos G; Timofeev, Ivan S; Corteen, Elizabeth A; Czosnyka, Marek; Timothy, Jake; Anderson, Ian; Bulters, Diederik O; Belli, Antonio; Eynon, C Andrew; Wadley, John; Mendelow, A David; Mitchell, Patrick M; Wilson, Mark H; Critchley, Giles; Sahuquillo, Juan; Unterberg, Andreas; Servadei, Franco; Teasdale, Graham M; Pickard, John D; Menon, David K; Murray, Gordon D; Kirkpatrick, Peter J

    2016-09-22

    Background The effect of decompressive craniectomy on clinical outcomes in patients with refractory traumatic intracranial hypertension remains unclear. Methods From 2004 through 2014, we randomly assigned 408 patients, 10 to 65 years of age, with traumatic brain injury and refractory elevated intracranial pressure (>25 mm Hg) to undergo decompressive craniectomy or receive ongoing medical care. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOS-E) (an 8-point scale, ranging from death to "upper good recovery" [no injury-related problems]) at 6 months. The primary-outcome measure was analyzed with an ordinal method based on the proportional-odds model. If the model was rejected, that would indicate a significant difference in the GOS-E distribution, and results would be reported descriptively. Results The GOS-E distribution differed between the two groups (P<0.001). The proportional-odds assumption was rejected, and therefore results are reported descriptively. At 6 months, the GOS-E distributions were as follows: death, 26.9% among 201 patients in the surgical group versus 48.9% among 188 patients in the medical group; vegetative state, 8.5% versus 2.1%; lower severe disability (dependent on others for care), 21.9% versus 14.4%; upper severe disability (independent at home), 15.4% versus 8.0%; moderate disability, 23.4% versus 19.7%; and good recovery, 4.0% versus 6.9%. At 12 months, the GOS-E distributions were as follows: death, 30.4% among 194 surgical patients versus 52.0% among 179 medical patients; vegetative state, 6.2% versus 1.7%; lower severe disability, 18.0% versus 14.0%; upper severe disability, 13.4% versus 3.9%; moderate disability, 22.2% versus 20.1%; and good recovery, 9.8% versus 8.4%. Surgical patients had fewer hours than medical patients with intracranial pressure above 25 mm Hg after randomization (median, 5.0 vs. 17.0 hours; P<0.001) but had a higher rate of adverse events (16.3% vs. 9.2%, P=0.03). Conclusions At 6

  4. Fabrication and Structural Design of Micro Pressure Sensors for Tire Pressure Measurement Systems (TPMS).

    Science.gov (United States)

    Tian, Bian; Zhao, Yulong; Jiang, Zhuangde; Zhang, Ling; Liao, Nansheng; Liu, Yuanhao; Meng, Chao

    2009-01-01

    In this paper we describe the design and testing of a micro piezoresistive pressure sensor for a Tire Pressure Measurement System (TPMS) which has the advantages of a minimized structure, high sensitivity, linearity and accuracy. Through analysis of the stress distribution of the diaphragm using the ANSYS software, a model of the structure was established. The fabrication on a single silicon substrate utilizes the technologies of anisotropic chemical etching and packaging through glass anodic bonding. The performance of this type of piezoresistive sensor, including size, sensitivity, and long-term stability, were investigated. The results indicate that the accuracy is 0.5% FS, therefore this design meets the requirements for a TPMS, and not only has a smaller size and simplicity of preparation, but also has high sensitivity and accuracy.

  5. Fabrication and Structural Design of Micro Pressure Sensors for Tire Pressure Measurement Systems (TPMS

    Directory of Open Access Journals (Sweden)

    Bian Tian

    2009-02-01

    Full Text Available In this paper we describe the design and testing of a micro piezoresistive pressure sensor for a Tire Pres