The Role of Cine Flow Magnetic Resonance Imaging in Patients with Chiari 0 Malformation.

Science.gov (United States)

Ozsoy, Kerem Mazhar; Oktay, Kadir; Cetinalp, Nuri Eralp; Gezercan, Yurdal; Erman, Tahsin

2018-01-01

To define the role of phase-contrast cine magnetic resonance imaging (MRI) in deciding the therapeutic strategy and underlying pathophysiology resulting in syrinx formation in patients with Chiari type 0 malformation. Seven patients who were admitted to our clinic with the diagnosis of Chiari 0 malformation from January 2005 to July 2016 were enrolled in the study. All patients underwent a detailed preoperative neurological examination. Entire neuroaxis MRI and phase-contrast cine MRI were obtained preoperatively and postoperatively. Seven patients (5 female and 2 male) with Chiari type 0 malformation fulfilled the inclusion criteria. All of the patients had absent cine flow at the craniovertebral junction except two patients. These five patients underwent surgical interventions; suboccipital decompression and duraplasty. All of them showed both clinical and radiological improvement in the postoperative period. Cine flow MRI appears to be a useful tool in the management of patients with Chiari 0 malformation. There was a good correlation between the clinical presentation and cine flow preoperatively, and between clinical improvement and cine flow in the postoperative period.

Effects of flow sheet implementation on physician performance in the management of asthmatic patients.

Science.gov (United States)

Ruoff, Gary

2002-01-01

This project focused on increasing compliance, in a large family practice group, with quality indicators for the management of asthma. The objective was to determine if use of a flow sheet incorporating the Global Initiative for Asthma (GINA) guidelines could improve compliance with those guidelines if the flow sheet was placed in patients' medical records. After review and selection of 14 clinical quality indicators, physicians in the practice implemented a flow sheet as an intervention. These flow sheets were inserted into the records of 122 randomly selected patients with asthma. Medical records were reviewed before the flow sheets were placed in the records, and again approximately 6 months later, to determine if there was a change in compliance with the quality indicators. Improvement of documentation was demonstrated in 13 of the 14 quality indicators. The results indicate that compliance with asthma management quality indicators can improve with the use of a flow sheet.

Metformin, but not glimepiride, improves carotid artery diameter and blood flow in patients with type 2 diabetes mellitus

Directory of Open Access Journals (Sweden)

Helena Atroch Machado

2012-07-01

Full Text Available OBJECTIVE: To compare the effects of glimepiride and metformin on vascular reactivity, hemostatic factors and glucose and lipid profiles in patients with type 2 diabetes. METHODS: A prospective study was performed in 16 uncontrolled patients with diabetes previously treated with dietary intervention. The participants were randomized into metformin or glimepiride therapy groups. After four months, the patients were crossed over with no washout period to the alternative treatment for an additional four-month period on similar dosage schedules. The following variables were assessed before and after four months of each treatment: 1 fasting glycemia, insulin, catecholamines, lipid profiles and HbA1 levels; 2 t-PA and PAI-1 (antigen and activity, platelet aggregation and fibrinogen and plasminogen levels; and 3 the flow indices of the carotid and brachial arteries. In addition, at the end of each period, a 12-hour metabolic profile was obtained after fasting and every 2 hours thereafter. RESULTS: Both therapies resulted in similar decreases in fasting glucose, triglyceride and norepinephrine levels, and they increased the fibrinolytic factor plasminogen but decreased t-PA activity. Metformin caused lower insulin and pro-insulin levels and higher glucagon levels and increased systolic carotid diameter and blood flow. Neither metformin nor glimepiride affected endothelial-dependent or endothelial-independent vasodilation of the brachial artery. CONCLUSIONS: Glimepiride and metformin were effective in improving glucose and lipid profiles and norepinephrine levels. Metformin afforded more protection against macrovascular diabetes complications, increased systolic carotid artery diameter and total and systolic blood flow, and decreased insulin levels. As both therapies increased plasminogen levels but reduced t-PA activity, a coagulation process was likely still ongoing.

Doppler Endoscopic Probe Monitoring of Blood Flow Improves Risk Stratification and Outcomes of Patients With Severe Nonvariceal Upper Gastrointestinal Hemorrhage.

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Jensen, Dennis M; Kovacs, Thomas O G; Ohning, Gordon V; Ghassemi, Kevin; Machicado, Gustavo A; Dulai, Gareth S; Sedarat, Alireza; Jutabha, Rome; Gornbein, Jeffrey

2017-05-01

For 4 decades, stigmata of recent hemorrhage in patients with nonvariceal lesions have been used for risk stratification and endoscopic hemostasis. The arterial blood flow that underlies the stigmata rarely is monitored, but can be used to determine risk for rebleeding. We performed a randomized controlled trial to determine whether Doppler endoscopic probe monitoring of blood flow improves risk stratification and outcomes in patients with severe nonvariceal upper gastrointestinal hemorrhage. In a single-blind study performed at 2 referral centers we assigned 148 patients with severe nonvariceal upper gastrointestinal bleeding (125 with ulcers, 19 with Dieulafoy's lesions, and 4 with Mallory Weiss tears) to groups that underwent standard, visually guided endoscopic hemostasis (control, n = 76), or endoscopic hemostasis assisted by Doppler monitoring of blood flow under the stigmata (n = 72). The primary outcome was the rate of rebleeding after 30 days; secondary outcomes were complications, death, and need for transfusions, surgery, or angiography. There was a significant difference in the rates of lesion rebleeding within 30 days of endoscopic hemostasis in the control group (26.3%) vs the Doppler group (11.1%) (P = .0214). The odds ratio for rebleeding with Doppler monitoring was 0.35 (95% confidence interval, 0.143-0.8565) and the number needed to treat was 7. In a randomized controlled trial of patients with severe upper gastrointestinal hemorrhage from ulcers or other lesions, Doppler probe guided endoscopic hemostasis significantly reduced 30-day rates of rebleeding compared with standard, visually guided hemostasis. Guidelines for nonvariceal gastrointestinal bleeding should incorporate these results. ClinicalTrials.gov no: NCT00732212 (CLIN-013-07F). Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI

International Nuclear Information System (INIS)

Jarvis, Kelly; Markl, Michael; Schnell, Susanne; Barker, Alex J.; Garcia, Julio; Chowdhary, Varun; Carr, James; Lorenz, Ramona; Rose, Michael; Robinson, Joshua D.; Rigsby, Cynthia K.

2016-01-01

Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R"2=0.50, P=0.02; SVC to LPA: R"2=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability. (orig.)

Evaluation of blood flow distribution asymmetry and vascular geometry in patients with Fontan circulation using 4-D flow MRI

Energy Technology Data Exchange (ETDEWEB)

Jarvis, Kelly; Markl, Michael [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Chicago, IL (United States); Schnell, Susanne; Barker, Alex J.; Garcia, Julio; Chowdhary, Varun; Carr, James [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Lorenz, Ramona [University Medical Center Freiburg, Department of Radiology, Freiburg (Germany); Rose, Michael [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Robinson, Joshua D. [Northwestern University, Department of Pediatrics, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert H. Lurie Children' s Hospital of Chicago, Division of Cardiology, Chicago, IL (United States); Rigsby, Cynthia K. [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

2016-10-15

Asymmetrical caval to pulmonary blood flow is suspected to cause complications in patients with Fontan circulation. The aim of this study was to test the feasibility of 4-D flow MRI for characterizing the relationship between 3-D blood flow distribution and vascular geometry. We hypothesized that both flow distribution and geometry can be calculated with low interobserver variability and will detect a direct relationship between flow distribution and Fontan geometry. Four-dimensional flow MRI was acquired in 10 Fontan patients (age: 16 ± 4 years [mean ± standard deviation], range: 9-21 years). The Fontan connection was isolated by 3-D segmentation to evaluate flow distribution from the inferior vena cava (IVC) and superior vena cava (SVC) to the left and right pulmonary arteries (LPA, RPA) and to characterize geometry (cross-sectional area, caval offset, vessel angle). Flow distribution results indicated SVC flow tended toward the RPA while IVC flow was more evenly distributed (SVC to RPA: 78% ± 28 [9-100], IVC to LPA: 54% ± 28 [4-98]). There was a significant relationship between pulmonary artery cross-sectional area and flow distribution (IVC to RPA: R{sup 2}=0.50, P=0.02; SVC to LPA: R{sup 2}=0.81, P=0.0004). Good agreement was found between observers and for flow distribution when compared to net flow values. Four-dimensional flow MRI was able to detect relationships between flow distribution and vessel geometry. Future studies are warranted to investigate the potential of patient specific hemodynamic analysis to improve diagnostic capability. (orig.)

The additional benefit of the ML Flow test to classify leprosy patients.

Science.gov (United States)

Bührer-Sékula, Samira; Illarramendi, Ximena; Teles, Rose B; Penna, Maria Lucia F; Nery, José Augusto C; Sales, Anna Maria; Oskam, Linda; Sampaio, Elizabeth P; Sarno, Euzenir N

2009-08-01

The use of the skin lesion counting classification leads to both under and over diagnosis of leprosy in many instances. Thus, there is a need to complement this classification with another simple and robust test for use in the field. Data of 202 untreated leprosy patients diagnosed at FIOCRUZ, Rio de Janeiro, Brazil, was analyzed. There were 90 patients classified as PB and 112 classified as MB according to the reference standard. The BI was positive in 111 (55%) patients and the ML Flow test in 116 (57.4%) patients. The ML Flow test was positive in 95 (86%) of the patients with a positive BI. The lesion counting classification was confirmed by both BI and ML Flow tests in 65% of the 92 patients with 5 or fewer lesions, and in 76% of the 110 patients with 6 or more lesions. The combination of skin lesion counting and the ML Flow test results yielded a sensitivity of 85% and a specificity of 87% for MB classification, and correctly classified 86% of the patients when compared to the standard reference. A considerable proportion of the patients (43.5%) with discordant test results in relation to standard classification was in reaction. The use of any classification system has limitations, especially those that oversimplify a complex disease such as leprosy. In the absence of an experienced dermatologist and slit skin smear, the ML Flow test could be used to improve treatment decisions in field conditions.

Lean techniques to improve the flow of critically ill patients in a health region with its epicenter in the intensive care unit of a reference hospital.

Science.gov (United States)

Sirvent, J M; Gil, M; Alvarez, T; Martin, S; Vila, N; Colomer, M; March, E; Loma-Osorio, P; Metje, T

2016-01-01

To analyze whether the application of Lean techniques to improve the flow of critically ill patients in a health region with its epicenter in the intensive care unit (ICU) of a reference hospital. Observational study with pre and post intervention analysis. ICU of a reference hospital. We design projects and a value stream map of flow and compared pre and post intervention. We recorded demographic data, patient transfers by EMS for lack of beds and delay times in the discharge from ICU to ward. Multidisciplinary meetings and perform daily visual panel, with high priority ICU discharge. We promote temporary relocation of critically ill patients in other special areas of the hospital. We performed a professional satisfaction questionnaire with pre and post implementation of process. We make a statistical analysis of pre and post-intervention comparisons. We planned for 2013 and progressively implemented in 2014. Analysis of patients entering the critical process flow 1) evaluate patients who must transfer for lack of beds, focusing on a diagnosis: pre 10/22 vs. 3/21 post (P=.045); 2) analysis of time delay in the discharge from the ICU to ward: 360.8±163.9minutes in the first period vs. 276.7±149.5 in the second (P=.036); and 3) personal professional satisfaction questionnaire, with 6.6±1.5 points pre vs. 7.5±1.1 in post (P=.001). Analysis of indicators such as the ICU acquired infections, length of ICU stay, the rate of re-admissions and mortality, with no significant differences between the two periods. The application of Lean techniques in the critically ill process had a positive impact on improving patient flow within the health region, noting a decrease of transfers outside the region due to lack of beds, reduced delayed discharge from ICU to conventional ward and increased satisfaction of ICU professionals. Copyright © 2015 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Axiomatic Design of a Framework for the Comprehensive Optimization of Patient Flows in Hospitals

Directory of Open Access Journals (Sweden)

Gabriele Arcidiacono

2017-01-01

Full Text Available Lean Management and Six Sigma are nowadays applied not only to the manufacturing industry but also to service industry and public administration. The manifold variables affecting the Health Care system minimize the effect of a narrow Lean intervention. Therefore, this paper aims to discuss a comprehensive, system-based approach to achieve a factual holistic optimization of patient flows. This paper debates the efficacy of Lean principles applied to the optimization of patient flows and related activities, structures, and resources, developing a theoretical framework based on the principles of the Axiomatic Design. The demand for patient-oriented and efficient health services leads to use these methodologies to improve hospital processes. In the framework, patients with similar characteristics are clustered in families to achieve homogeneous flows through the value stream. An optimization checklist is outlined as the result of the mapping between Functional Requirements and Design Parameters, with the right sequence of the steps to optimize the patient flow according to the principles of Axiomatic Design. The Axiomatic Design-based top-down implementation of Health Care evidence, according to Lean principles, results in a holistic optimization of hospital patient flows, by reducing the complexity of the system.

Managing length of stay using patient flow--part 1.

Science.gov (United States)

Cesta, Toni

2013-02-01

This month we have discussed the fundamentals of patient flow and its related theories. We reviewed the concepts of demand and capacity management as they apply to the hospital setting. Patient flow requires daily diligence and attention. It should not be something focused on only on busy days, but should be managed each and every day. By taking a proactive approach to patient flow, the number of days your hospital will be bottlenecked can be reduced. Patient flow needs to be part of the daily activities of every case management department and should be factored in as a core role and function in a contemporary case management department. Patient flow needs to be addressed at the patient, departmental, and hospital level. In next month's issue we will continue our discussion on patient flow with a detailed review of specific examples that any case management department can use. We will also review all the departments and disciplines that contribute to patient flow and their role in it.

Realizing improved patient care through human-centered operating room design: a human factors methodology for observing flow disruptions in the cardiothoracic operating room.

Science.gov (United States)

Palmer, Gary; Abernathy, James H; Swinton, Greg; Allison, David; Greenstein, Joel; Shappell, Scott; Juang, Kevin; Reeves, Scott T

2013-11-01

Human factors engineering has allowed a systematic approach to the evaluation of adverse events in a multitude of high-stake industries. This study sought to develop an initial methodology for identifying and classifying flow disruptions in the cardiac operating room (OR). Two industrial engineers with expertise in human factors workflow disruptions observed 10 cardiac operations from the moment the patient entered the OR to the time they left for the intensive care unit. Each disruption was fully documented on an architectural layout of the OR suite and time-stamped during each phase of surgery (preoperative [before incision], operative [incision to skin closure], and postoperative [skin closure until the patient leaves the OR]) to synchronize flow disruptions between the two observers. These disruptions were then categorized. The two observers made a total of 1,158 observations. After the elimination of duplicate observations, a total of 1,080 observations remained to be analyzed. These disruptions were distributed into six categories such as communication, usability, physical layout, environmental hazards, general interruptions, and equipment failures. They were further organized into 33 subcategories. The most common disruptions were related to OR layout and design (33%). By using the detailed architectural diagrams, the authors were able to clearly demonstrate for the first time the unique role that OR design and equipment layout has on the generation of physical layout flow disruptions. Most importantly, the authors have developed a robust taxonomy to describe the flow disruptions encountered in a cardiac OR, which can be used for future research and patient safety improvements.

New heavy crude oil flow improver increases delivery : application scenarios

Energy Technology Data Exchange (ETDEWEB)

Pierce, J.; Johnston, R.; Lauzon, P. [ConocoPhillips Specialty Products Inc., Houston, TX (United States)

2009-07-01

Flow improvers or drag reducing agents have been used for over 25 years as a method to increase fluid flow in hydrocarbon pipelines. The technology is effective in refined projects, light and medium crude oils. This paper presented a new development in flow improver technology that allows treatment of heavy crude oil slates. It discussed case studies of flow improver treatment of heavy oils in various pipeline system as well as factors that affect commercial success. tabs., figs.

Regional cerebral blood flow in schizophrenic patients

International Nuclear Information System (INIS)

Sagawa, Katsuo; Sibuya, Isoo; Oiji, Arata; Kawakatsu, Sinobu; Morinobu, Shigeru; Totsuka, Shiro; Kinoshita, Osami; Yazaki, Mitsuyasu.

1990-01-01

Seventy-six schizophrenic patients were examined by a Xe-133 inhalation method to determine regional cerebral blood flow. A decreased blood flow was observed in the frontal lobe, especially in the right inferior part. In a study on the relationship between disease subtypes and regional cerebral blood flow, negative symptoms were found more predominantly associated with dissolution type than delusion type. In the group of dissolution type, a decreased blood flow was observed in both the right inferior frontal lobe and the right upper hemisphere, in comparison to the group of delution type. Patients presenting with auditory hallucination had a significantly higher incidence of both negative and positive symptoms, as compared with those not presenting with it. In such patients, a significantly decreased blood flow was also seen in the left upper frontal lobe and the bilateral parietal lobe. Xe-133 inhalation method should assist in evaluating brain function in schizophrenic patients, thus leading to the likelihood of developing a new treatment modality. (N.K.)

Regional cerebral blood flow in older patients with chronic subdural hematoma

International Nuclear Information System (INIS)

Hoshi, Yutaka; Fuse, Masaaki; Iio, Masahiro; Fuziwara, Keigo; Kawaguchi, Shinichiro

1978-01-01

Regional cerebral blood flow (rCBF) was measured in 4 regions (frontal, parietal, occipital, and temporal) over the entire hemisphere using modified 133 Xe clearance method in 5 patients with chronic subdural hematoma. In 5 patients, rCBF was measured both pre- and postoperation and those values were compared. CBF (average cerebral blood flow) measurements were compared. CBF measurements were carried out in each patients respectively, that is before the operation and 3 weeks after the operation. Before the operation, the presence of chronic subdural hematoma, but brought about only slight or moderate generalized decrease in rCBF. The older patients presented subnormal values of 31.5 - 45.1 ml/100 g/min. Mean f sub(g) (the flow in the grey matter) of 5 patients was 66.8 +- 5.0 ml/100 g/min on the hematoma site, 58.1 +- 2.8 ml/100 g/min on the non-hematoma site before operation. Three weeks after operation mean f sub(g) was 65.5 +- 7.6 ml/100 g/min on the non-hematoma site, 64.2 +- 3.5 ml/100 g/min on the hematoma site, and CBFr of non-hematoma site was 40.2 +- 5.7 ml/100 g/min and that of hematoma site, 38.5 +- 8.8 ml/100 g/min. These figures are moderately smaller than that of the normal values. A comparison between regional flow values noted in patients of pre- and post-operation who has a removal of hematomas indicated that the flow values of non-hematoma site increased slightly 3 weeks after operation, inspite of the only slight or no improvement in neurological features. But the flow values (f sub(g), CBFr) of hematoma site decreased 3 weeks after operation. It seems that post-operative follow up of mean cerebral blood flow change might be of help in the assessment of prognosis of operation. (auth.)

Regional cerebral blood flow in older patients with chronic subdural hematoma

Energy Technology Data Exchange (ETDEWEB)

Hoshi, Y; Fuse, M; Iio, M; Fuziwara, K; Kawaguchi, S [Tokyo Metropolitan Geriatric Medical Center (Japan)

1978-02-01

Regional cerebral blood flow (rCBF) was measured in 4 regions (frontal, parietal, occipital, and temporal) over the entire hemisphere using modified /sup 133/Xe clearance method in 5 patients with chronic subdural hematoma. In 5 patients, rCBF was measured both pre- and postoperation and those values were compared. CBF (average cerebral blood flow) measurements were compared. CBF measurements were carried out in each patients respectively, that is before the operation and 3 weeks after the operation. Before the operation, the presence of chronic subdural hematoma, but brought about only slight or moderate generalized decrease in rCBF. The older patients presented subnormal values of 31.5 - 45.1 ml/100 g/min. Mean f sub(g) (the flow in the grey matter) of 5 patients was 66.8 +- 5.0 ml/100 g/min on the hematoma site, 58.1 +- 2.8 ml/100 g/min on the non-hematoma site before operation. Three weeks after operation mean f sub(g) was 65.5 +- 7.6 ml/100 g/min on the non-hematoma site, 64.2 +- 3.5 ml/100 g/min on the hematoma site, and CBFr of non-hematoma site was 40.2 +- 5.7 ml/100 g/min and that of hematoma site, 38.5 +- 8.8 ml/100 g/min. These figures are moderately smaller than that of the normal values. A comparison between regional flow values noted in patients of pre- and post-operation who has a removal of hematomas indicated that the flow values of non-hematoma site increased slightly 3 weeks after operation, inspite of the only slight or no improvement in neurological features. But the flow values (f sub(g), CBFr) of hematoma site decreased 3 weeks after operation. It seems that post-operative follow up of mean cerebral blood flow change might be of help in the assessment of prognosis of operation.

Nasal highflow improves ventilation in patients with COPD

Directory of Open Access Journals (Sweden)

Bräunlich J

2016-05-01

Full Text Available Jens Bräunlich,* Marcus Köhler,* Hubert WirtzDepartment of Respiratory Medicine, University of Leipzig, Leipzig, Germany *These authors contributed equally to this workBackground: Nasal highflow (NHF provides a warmed and humidified air stream up to 60 L/min. Recent data demonstrated a positive effect in patients with acute hypoxemic respiratory failure, especially when caused by pneumonia. Preliminary data show a decrease in hypercapnia in patients with COPD. Therefore, NHF should be evaluated as a new ventilatory support device. This study was conducted to assess the impact of different flow rates on ventilatory parameters in patients with COPD.Materials and methods: This interventional clinical study was performed with patients suffering from severe COPD. The aim was to characterize flow-dependent changes in mean airway pressure, breathing volumes, breathing frequency, and decrease in partial pressure of CO2 (pCO2. Mean airway pressure was measured in the nasopharyngeal space (19 patients. To evaluate breathing volumes, we used a polysomnographic device (18 patients. All patients received 20 L/min, 30 L/min, 40 L/min, and 50 L/min and – to illustrate the effects – nasal continuous positive airway pressure and nasal bilevel positive airway pressure. Capillary blood gas analyses were performed in 54 patients with hypercapnic COPD before and two hours after the use of NHF. We compared the extent of decrease in pCO2 when using 20 L/min and 30 L/min. Additionally, comfort and dyspnea during the use of NHF were surveyed.Results: NHF resulted in a minor flow dependent increase in mean airway pressure. Tidal volume increased, and breathing rate decreased. The calculated minute volume decreased under NHF breathing. In spite of this fact, hypercapnia decreased with increasing flow (20 L/min vs 30 L/min. Additionally, an improvement in dyspnea was observed. The rapid shallow breathing index shows a decrease when using NHF.Conclusion: NHF

Improving patient experience in a pediatric ambulatory clinic: a mixed method appraisal of service delivery

Directory of Open Access Journals (Sweden)

Soeteman M

2015-03-01

Full Text Available Marijn Soeteman,1 Vera Peters,2 Jamiu O Busari1,3 1Department of Pediatrics, Atrium Medical Center, Heerlen, 2Faculty of Health, Medicine and Life Sciences, 3Department of Educational Development and Research, Faculty of Health, Medicine and Life Sciences, University of Maastricht, Maastricht, the Netherlands Objective: In 2013, customer satisfaction surveys showed that patients were unhappy with the services provided at our ambulatory clinic. In response, we performed an appraisal of our services, which resulted in the development of a strategy to reduce waiting time and improve quality of service. Infrastructural changes to our clinic’s waiting room, consultation rooms, and back offices were performed, and schedules were redesigned to reduce wait time to 10 minutes and increase consultation time to 20 minutes. Our objective was to identify if this would improve 1 accessibility to caregivers and 2 quality of service and available amenities. Design: We conducted a multi-method survey using 1 a patient flow analysis to analyze the flow of service and understand the impact of our interventions on patient flow and 2 specially designed questionnaires to investigate patients’ perceptions of our wait time and how to improve our services. Results: The results showed that 79% of our respondents were called in to see a doctor within 20 minutes upon arrival. More patients (55% felt that 10–20 minutes was an acceptable wait time. We also observed a perceived increase in satisfaction with wait time (94%. Finally, a large number of patients (97% were satisfied with the quality of service and with the accessibility to caregivers (94%. Conclusion: The majority of our patients were satisfied with the accessibility to our ambulatory clinics and with the quality of services provided. The appraisal of our operational processes using a patient flow analysis also demonstrated how this strategy could effectively be applied to investigate and improve quality of

Axiomatic Design of a Framework for the Comprehensive Optimization of Patient Flows in Hospitals

Science.gov (United States)

Arcidiacono, Gabriele; Matt, Dominik T.; Rauch, Erwin

2017-01-01

Lean Management and Six Sigma are nowadays applied not only to the manufacturing industry but also to service industry and public administration. The manifold variables affecting the Health Care system minimize the effect of a narrow Lean intervention. Therefore, this paper aims to discuss a comprehensive, system-based approach to achieve a factual holistic optimization of patient flows. This paper debates the efficacy of Lean principles applied to the optimization of patient flows and related activities, structures, and resources, developing a theoretical framework based on the principles of the Axiomatic Design. The demand for patient-oriented and efficient health services leads to use these methodologies to improve hospital processes. In the framework, patients with similar characteristics are clustered in families to achieve homogeneous flows through the value stream. An optimization checklist is outlined as the result of the mapping between Functional Requirements and Design Parameters, with the right sequence of the steps to optimize the patient flow according to the principles of Axiomatic Design. The Axiomatic Design-based top-down implementation of Health Care evidence, according to Lean principles, results in a holistic optimization of hospital patient flows, by reducing the complexity of the system. © 2017 Gabriele Arcidiacono et al.

EFFICACY OF LASER PULSE FREQUENCIES ON BLOOD FLOW IN TYPE 2 DIABETIC PATIENTS

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Amir Nazih Wadee

2017-04-01

Full Text Available Background: Research reports had noted an apparent increase in cutaneous and deep blood flow as a result of low-intensity laser therapy (LLLT in normal subjects. The purpose of te study was to investigate the effective laser pulse frequency either (200 or 2000 Hz on improving blood flow in type 2 diabetic patients. Forty-five diabetic patients selected from out clinic of Kasr El-Aini Hospital, Cairo University assigned randomly into three groups. The blood flow volume, blood flow velocity and caliper of the blood vessel were evaluated before laser application and after twelve sessions using duplex Doppler ultrasound. Methods: Combined He-Ne and infrared LILT was administered three times a week for twelve sessions at intensity of 3 J, power 500 mW, 808 nm duration 15 min and pulse frequency 200 Hz for group I, 2000 Hz for group II, and sham LILT for group III on the sural artery at posterior aspect of dominant leg. Result: Paired t-test revealed that low pulse frequency (200 Hz LILT produced significant improvement in blood flow volume and blood flow velocity (t= 1.76, p= 0.001 and t= 2.8, p= 0.01 respectively (P<0.05. While there was no significant changes in caliper of the blood vessel of group I, blood flow volume, blood flow velocity or caliper of the blood vessel of group II and group III (t= 2.15, p= 1, t= 2.15, p= 1, t= 1.11 p= 0.31, t= 1.54, p= 0.15, t= 2.51, p= 1, t= 1.21 p= 0.33, t= 1.45, p= 0.15 respectively (P<0.05. ANOVA test in between groups revealed insignificant changes in all pre and post- measures except significant results in blood flow volume and velocity which indicating the superiority of group I on both group II and III by post hoc test. Conclusion: low pulse frequency of LILT (200 Hz could improve blood flow than high pulse frequency (2000 Hz.

Non-Invasive Mapping of Intraventricular Flow Patterns in Patients Treated with Left Ventricular Assist Devices

Science.gov (United States)

Miramontes, Marissa; Rossini, Lorenzo; Braun, Oscar; Brambatti, Michela; Almeida, Shone; Mizeracki, Adam; Martinez-Legazpi, Pablo; Benito, Yolanda; Bermejo, Javier; Kahn, Andrew; Adler, Eric; Del Álamo, Juan C.

2017-11-01

In heart failure patients, left ventricular (LV) assist devices (LVADs) decrease mortality and improve quality of life. We hypothesize echo color Doppler velocimetry (echo-CDV), an echocardiographic flow mapping modality, can non-invasively characterize the effect of LVAD support, optimize the device, thereby decreasing the stoke rate present in these patients. We used echo-CDV to image LV flow at baseline LVAD speed and during a ramp test in LVAD patients (Heartmate II, N =10). We tracked diastolic vortices and mapped blood stasis and cumulative shear. Compared to dilated cardiomyopathy (DCM) patients without LVADs, the flow had a less prominent diastolic vortex ring, and transited directly from mitral valve to cannula. Residence time and shear were significantly lower compared to healthy controls and DCMs. Aortic regurgitation and a large LV vortex presence or a direct mitral jet towards the cannula affected blood stasis region location and size. Flow patterns, residence time and shear depended on LV geometry, valve function and LVAD speed in a patient specific manner. This new methodology could be used with standard echo, hemodynamics and clinical information to find the flow optimizing LAVD setting minimizing stasis for each patient.

Improving the quality of palliative care for ambulatory patients with lung cancer

DEFF Research Database (Denmark)

von Plessen, Christian; Aslaksen, Aslak

2005-01-01

and energy in organisational aspects of care that could be better used in direct interaction with patients. DESIGN: Quality improvement study using direct observation and run and flow charts, and focus group meetings with patients and families regarding perceptions of the clinic and with staff regarding...

Improving ecological response monitoring of environmental flows.

Science.gov (United States)

King, Alison J; Gawne, Ben; Beesley, Leah; Koehn, John D; Nielsen, Daryl L; Price, Amina

2015-05-01

Environmental flows are now an important restoration technique in flow-degraded rivers, and with the increasing public scrutiny of their effectiveness and value, the importance of undertaking scientifically robust monitoring is now even more critical. Many existing environmental flow monitoring programs have poorly defined objectives, nonjustified indicator choices, weak experimental designs, poor statistical strength, and often focus on outcomes from a single event. These negative attributes make them difficult to learn from. We provide practical recommendations that aim to improve the performance, scientific robustness, and defensibility of environmental flow monitoring programs. We draw on the literature and knowledge gained from working with stakeholders and managers to design, implement, and monitor a range of environmental flow types. We recommend that (1) environmental flow monitoring programs should be implemented within an adaptive management framework; (2) objectives of environmental flow programs should be well defined, attainable, and based on an agreed conceptual understanding of the system; (3) program and intervention targets should be attainable, measurable, and inform program objectives; (4) intervention monitoring programs should improve our understanding of flow-ecological responses and related conceptual models; (5) indicator selection should be based on conceptual models, objectives, and prioritization approaches; (6) appropriate monitoring designs and statistical tools should be used to measure and determine ecological response; (7) responses should be measured within timeframes that are relevant to the indicator(s); (8) watering events should be treated as replicates of a larger experiment; (9) environmental flow outcomes should be reported using a standard suite of metadata. Incorporating these attributes into future monitoring programs should ensure their outcomes are transferable and measured with high scientific credibility.

Improving Ecological Response Monitoring of Environmental Flows

Science.gov (United States)

King, Alison J.; Gawne, Ben; Beesley, Leah; Koehn, John D.; Nielsen, Daryl L.; Price, Amina

2015-05-01

Environmental flows are now an important restoration technique in flow-degraded rivers, and with the increasing public scrutiny of their effectiveness and value, the importance of undertaking scientifically robust monitoring is now even more critical. Many existing environmental flow monitoring programs have poorly defined objectives, nonjustified indicator choices, weak experimental designs, poor statistical strength, and often focus on outcomes from a single event. These negative attributes make them difficult to learn from. We provide practical recommendations that aim to improve the performance, scientific robustness, and defensibility of environmental flow monitoring programs. We draw on the literature and knowledge gained from working with stakeholders and managers to design, implement, and monitor a range of environmental flow types. We recommend that (1) environmental flow monitoring programs should be implemented within an adaptive management framework; (2) objectives of environmental flow programs should be well defined, attainable, and based on an agreed conceptual understanding of the system; (3) program and intervention targets should be attainable, measurable, and inform program objectives; (4) intervention monitoring programs should improve our understanding of flow-ecological responses and related conceptual models; (5) indicator selection should be based on conceptual models, objectives, and prioritization approaches; (6) appropriate monitoring designs and statistical tools should be used to measure and determine ecological response; (7) responses should be measured within timeframes that are relevant to the indicator(s); (8) watering events should be treated as replicates of a larger experiment; (9) environmental flow outcomes should be reported using a standard suite of metadata. Incorporating these attributes into future monitoring programs should ensure their outcomes are transferable and measured with high scientific credibility.

Intensive insulin treatment improves forearm blood flow in critically ill patients: a randomized parallel design clinical trial.

Science.gov (United States)

Žuran, Ivan; Poredos, Pavel; Skale, Rafael; Voga, Gorazd; Gabrscek, Lucija; Pareznik, Roman

2009-01-01

Intensive insulin treatment of critically ill patients was seen as a promising method of treatment, though recent studies showed that reducing the blood glucose level below 6 mmol/l had a detrimental outcome. The mechanisms of the effects of insulin in the critically ill are not completely understood. The purpose of the study was to test the hypothesis that intensive insulin treatment may influence forearm blood flow independently of global hemodynamic indicators. The study encompassed 29 patients of both sexes who were admitted to the intensive care unit due to sepsis and required artificial ventilation as the result of acute respiratory failure. 14 patients were randomly selected for intensive insulin treatment (Group 1; blood glucose concentration 4.4-6.1 mmol/l), and 15 were selected for conventional insulin treatment (Group 2; blood glucose level 7.0 mmol/l-11.0 mmol/l). At the start of the study (t0, beginning up to 48 hours after admittance and the commencement of artificial ventilation), at 2 hours (t1), 24 hours (t2), and 72 hours (t3) flow in the forearm was measured for 60 minutes using the strain-gauge plethysmography method. Student's t-test of independent samples was used for comparisons between the two groups, and Mann-Whitney's U-test where appropriate. Linear regression analysis and the Pearson correlation coefficient were used to determine the levels of correlation. The difference in 60-minute forearm flow at the start of the study (t0) was not statistically significant between groups, while at t2 and t3 significantly higher values were recorded in Group 1 (t2; Group 1: 420.6 +/- 188.8 ml/100 ml tissue; Group 2: 266.1 +/- 122.2 ml/100 ml tissue (95% CI 30.9-278.0, P = 0.02); t3; Group 1: 369.9 +/- 150.3 ml/100 ml tissue; Group 2: 272.6 +/- 85.7 ml/100 ml tissue (95% CI 5.4-190.0, P = 0.04). At t1 a trend towards significantly higher values in Group 1 was noted (P = 0.05). The level of forearm flow was related to the amount of insulin infusion (r

Improving Patient Safety: Improving Communication.

Science.gov (United States)

Bittner-Fagan, Heather; Davis, Joshua; Savoy, Margot

2017-12-01

Communication among physicians, staff, and patients is a critical element in patient safety. Effective communication skills can be taught and improved through training and awareness. The practice of family medicine allows for long-term relationships with patients, which affords opportunities for ongoing, high-quality communication. There are many barriers to effective communication, including patient factors, clinician factors, and system factors, but tools and strategies exist to address these barriers, improve communication, and engage patients in their care. Use of universal precautions for health literacy, appropriate medical interpreters, and shared decision-making are evidence-based tools that improve communication and increase patient safety. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

Methods and Models for Capacity and Patient Flow Analysis in Hospital Sector

DEFF Research Database (Denmark)

Kozlowski, Dawid

at a private hospital in Denmark or at a hospital abroad if the public healthcare system is unable to provide treatment within the stated maximum waiting time guarantee. A queue modelling approach is used to analyse the potential negative consequences of the policy on the utilization of public hospital......This thesis is concerned about the novel applications of operations research methods for capacity and flow analysis within hospital sector. The first part of the thesis presents a detailed Discrete-Event Simulation (DES) model that has been developed as an analytical tool designed to facilitate...... by an improved patient flow. The specially developed structure of the model facilitates its reuse at different units, with no advanced modelling skills required in day-to-day use. This feature amplifies the usefulness of DES in conducting comprehensive patient flow analyses at any department with emergency...

High-flow nasal cannula therapy for adult patients

Science.gov (United States)

Zhang, Jian; Lin, Ling; Pan, Konghan; Zhou, Jiancang

2016-01-01

High-flow nasal cannula (HFNC) oxygen therapy has several physiological advantages over traditional oxygen therapy devices, including decreased nasopharyngeal resistance, washing out of the nasopharyngeal dead space, generation of positive pressure in the pharynx, increasing alveolar recruitment in the lungs, humidification of the airways, increased fraction of inspired oxygen and improved mucociliary clearance. Recently, the use of HFNC in treating adult critical illness patients has significantly increased, and it is now being used in many patients with a range of different disease conditions. However, there are no established guidelines to direct the safe and effective use of HFNC for these patients. This review article summarizes the available published literature on the positive physiological effects, mechanisms of action, and the clinical applications of HFNC, compared with traditional oxygen therapy devices. The available literature suggests that HFNC oxygen therapy is an effective modality for the early treatment of critically adult patients. PMID:27698207

Abnormality in cerebellar blood flow in solo vertigo patients

Energy Technology Data Exchange (ETDEWEB)

Nagahori, Takeshi [Shakaihoken Takaoka Hospital, Toyama (Japan); Nishijima, Michiharu; Endo, Shunro; Takaku, Akira

1997-03-01

Little is known about the blood flow of the vertebrobasilar system as a cause of vertigo and dizziness. We used Xe-CT to study cerebellar blood flow in 53 patients who ranged in age from 35 to 85 years. The patients were divided into two groups. One of them was the vertigo group that comprised 28 patients with rotatory sensation, and the other, the non-vertigo group of 25 patients with a sensation other than rotation. At the stage of severe symptoms, there was decreased cerebellar blood flow in all patients of both, the vertigo and the non-vertigo groups, and a decrease in the bilateral cerebellar hemisphere was observed in five patients and in a unilateral hemisphere in three patients of the vertigo group. By comparison, in the non-vertigo group, unilateral decrease of cerebellar blood flow was observed in only one patient, and a bilateral decrease in five. At the stage of severe symptoms, the mean regional cerebellar blood flow was 40.5{+-}8.0 ml/100 g/min (n=16 sides) in the vertigo group and 45.3{+-}9.5 ml/100 g/min (n=12 sides) in the non-vertigo group. At the stage of moderate symptoms, blood flow image was normal in four of 14 vertigo patients and in seven of 12 non-vertigo patients. The mean regional blood flow was 47.8{+-}8.6 ml/100 g/min (n=28 sides) in the vertigo group and 47.1{+-}5.1 ml/100 g/min (n=24 sides) in the non-vertigo group. At the asymptomatic stage, a high proportion of normal blood flow images (nine of 16 vertigo patients and 10 of 10 non-vertigo patients) was observed. The mean regional cerebellar blood flow was 51.6{+-}10.7 ml/100 g/min (n=32 sides) in the vertigo group and 52.8{+-}8.5 ml/100 g/min (n=20 sides) in the non-vertigo group. This study demonstrates that a unilateral or bilateral decrease in blood flow of the vertebrobasilar system may cause vertigo and dizziness. It also shows that Xe-CT of the cerebellum may be a valuable examination modality for the diagnosis and treatment of vertigo and dizziness. (author)

Abnormality in cerebellar blood flow in solo vertigo patients

International Nuclear Information System (INIS)

Nagahori, Takeshi; Nishijima, Michiharu; Endo, Shunro; Takaku, Akira

1997-01-01

Little is known about the blood flow of the vertebrobasilar system as a cause of vertigo and dizziness. We used Xe-CT to study cerebellar blood flow in 53 patients who ranged in age from 35 to 85 years. The patients were divided into two groups. One of them was the vertigo group that comprised 28 patients with rotatory sensation, and the other, the non-vertigo group of 25 patients with a sensation other than rotation. At the stage of severe symptoms, there was decreased cerebellar blood flow in all patients of both, the vertigo and the non-vertigo groups, and a decrease in the bilateral cerebellar hemisphere was observed in five patients and in a unilateral hemisphere in three patients of the vertigo group. By comparison, in the non-vertigo group, unilateral decrease of cerebellar blood flow was observed in only one patient, and a bilateral decrease in five. At the stage of severe symptoms, the mean regional cerebellar blood flow was 40.5±8.0 ml/100 g/min (n=16 sides) in the vertigo group and 45.3±9.5 ml/100 g/min (n=12 sides) in the non-vertigo group. At the stage of moderate symptoms, blood flow image was normal in four of 14 vertigo patients and in seven of 12 non-vertigo patients. The mean regional blood flow was 47.8±8.6 ml/100 g/min (n=28 sides) in the vertigo group and 47.1±5.1 ml/100 g/min (n=24 sides) in the non-vertigo group. At the asymptomatic stage, a high proportion of normal blood flow images (nine of 16 vertigo patients and 10 of 10 non-vertigo patients) was observed. The mean regional cerebellar blood flow was 51.6±10.7 ml/100 g/min (n=32 sides) in the vertigo group and 52.8±8.5 ml/100 g/min (n=20 sides) in the non-vertigo group. This study demonstrates that a unilateral or bilateral decrease in blood flow of the vertebrobasilar system may cause vertigo and dizziness. It also shows that Xe-CT of the cerebellum may be a valuable examination modality for the diagnosis and treatment of vertigo and dizziness. (author)

Electronic patient journey boards a vital piece of the puzzle in patient flow.

Science.gov (United States)

Clark, Kevin W; Moller, Susan; O'Brien, Lauri

2014-06-01

Internationally, there is growing interest in the applicability of visual management in healthcare, although little is known about the extent of its effectiveness. In the past 5 years technical advances have permitted the integration of all relevant data into a singular display that can improve staff efficiency, accelerate decisions, streamline workflow processes and reduce oversights and errors in clinical practice. The aim of the case study is to describe the features and application of electronic patient journey boards (EPJBs) as an enabler to accelerate patient flow that has been demonstrated and evaluated in Queensland Health hospitals. In 2012 and 2013 we collected ward-specific data that was sourced from the Queensland Hospital Admitted Patient Data Collection, determining the top 10 overnight diagnostic-related groups (DRGs) for each ward participating in the pilots. The Statistical Output Unit within Queensland Health then provided data and analysis on the ALOS for each of these DRGs for the period following an EPJB installation, along with the ALOS for the same DRGs for the corresponding period in the previous year. Patient length of stay reduced and display of estimated discharge dates improved with the introduction of EPJBs along with improved communication and information management resulting in time savings from 20 min per staff member per shift to 2.5h per ward a day. Queensland and South Australian Health systems have succeeded in 'making the hospital patient journey visible' through an innovative combination of information management and prominent display of key information related to patient care portrayed on large liquid crystal display (LCD) screens in hospital wards.

Educate patients on billing policies to improve your bottom line.

Science.gov (United States)

May, Jonathan

2006-01-01

In no other industry are the consumers of goods or services so unaware and uninvolved in the reimbursement for the goods or services received. The United States healthcare industry has created and allowed to perpetuate a "hands-off" compensation approach that has created a consumer mentality proving quite difficult to change. In this article, the author describes the origin of this outdated approach and suggests a restructured office and clear communication with patients as starting points to change this deep-rooted mind-set. He describes how an up-front approach to patients' financial responsibilities and proactive staff can help reduce miscommunication between provider, patient, and insurance carrier and improve your practice's cash flow. The author also suggests that the patient's financial burden will continue to increase and offers tips to maintain positive patient relationships, improve your accounts receivable management, and protect you financially.

Flow improvers for water injection based on surfactants

Energy Technology Data Exchange (ETDEWEB)

Oskarsson, H.; Uneback, I.; Hellsten, M.

2006-03-15

In many cases it is desirable to increase the flow of injection water when an oil well deteriorates. It is very costly in offshore operation to lay down an additional water pipe to the injection site. Flow improvers for the injection water will thus be the most cost-effective way to increase the flow rate. During the last years water-soluble polymers have also been applied for this purpose. These drag-reducing polymers are however only slowly biodegraded which has been an incentive for the development of readily biodegradable surfactants as flow improvers for injection water. A combination of a zwitterionic and an anionic surfactant has been tested in a 5.5 inch, 700 m long flow loop containing sulphate brine with salinity similar to sea water. A drag reduction between 75 and 80% was achieved with 119 ppm in solution of the surfactant blend at an average velocity of 1.9 m/s and between 50 and 55% at 2.9 m/s. The surfactants in this formulation were also found to be readily biodegradable in sea water and low bio accumulating which means they have an improved environmental profile compared to the polymers used today. Due to the self-healing properties of the drag-reducing structures formed by surfactants, these may be added before the pump section - contrary to polymers which are permanently destroyed by high shear forces. (Author)

Improved choked flow model for MARS code

International Nuclear Information System (INIS)

Chung, Moon Sun; Lee, Won Jae; Ha, Kwi Seok; Hwang, Moon Kyu

2002-01-01

Choked flow calculation is improved by using a new sound speed criterion for bubbly flow that is derived by the characteristic analysis of hyperbolic two-fluid model. This model was based on the notion of surface tension for the interfacial pressure jump terms in the momentum equations. Real eigenvalues obtained as the closed-form solution of characteristic polynomial represent the sound speed in the bubbly flow regime that agrees well with the existing experimental data. The present sound speed shows more reasonable result in the extreme case than the Nguyens did. The present choked flow criterion derived by the present sound speed is employed in the MARS code and assessed by using the Marviken choked flow tests. The assessment results without any adjustment made by some discharge coefficients demonstrate more accurate predictions of choked flow rate in the bubbly flow regime than those of the earlier choked flow calculations. By calculating the Typical PWR (SBLOCA) problem, we make sure that the present model can reproduce the reasonable transients of integral reactor system

Improving flow distribution in influent channels using computational fluid dynamics.

Science.gov (United States)

Park, No-Suk; Yoon, Sukmin; Jeong, Woochang; Lee, Seungjae

2016-10-01

Although the flow distribution in an influent channel where the inflow is split into each treatment process in a wastewater treatment plant greatly affects the efficiency of the process, and a weir is the typical structure for the flow distribution, to the authors' knowledge, there is a paucity of research on the flow distribution in an open channel with a weir. In this study, the influent channel of a real-scale wastewater treatment plant was used, installing a suppressed rectangular weir that has a horizontal crest to cross the full channel width. The flow distribution in the influent channel was analyzed using a validated computational fluid dynamics model to investigate (1) the comparison of single-phase and two-phase simulation, (2) the improved procedure of the prototype channel, and (3) the effect of the inflow rate on flow distribution. The results show that two-phase simulation is more reliable due to the description of the free-surface fluctuations. It should first be considered for improving flow distribution to prevent a short-circuit flow, and the difference in the kinetic energy with the inflow rate makes flow distribution trends different. The authors believe that this case study is helpful for improving flow distribution in an influent channel.

Luteal blood flow in patients undergoing GnRH agonist long protocol

Directory of Open Access Journals (Sweden)

Takasaki Akihisa

2011-01-01

Full Text Available Abstract Background Blood flow in the corpus luteum (CL is closely related to luteal function. It is unclear how luteal blood flow is regulated. Standardized ovarian-stimulation protocol with a gonadotropin-releasing hormone agonist (GnRHa long protocol causes luteal phase defect because it drastically suppresses serum LH levels. Examining luteal blood flow in the patient undergoing GnRHa long protocol may be useful to know whether luteal blood flow is regulated by LH. Methods Twenty-four infertile women undergoing GnRHa long protocol were divided into 3 groups dependent on luteal supports; 9 women were given ethinylestradiol plus norgestrel (Planovar orally throughout the luteal phase (control group; 8 women were given HCG 2,000 IU on days 2 and 4 day after ovulation induction in addition to Planovar (HCG group; 7 women were given vitamin E (600 mg/day orally throughout the luteal phase in addition to Planovar (vitamin E group. Blood flow impedance was measured in each CL during the mid-luteal phase by transvaginal color-pulsed-Doppler-ultrasonography and was expressed as a CL-resistance index (CL-RI. Results Serum LH levels were remarkably suppressed in all the groups. CL-RI in the control group was more than the cutoff value (0.51, and only 2 out of 9 women had CL-RI values Conclusion Patients undergoing GnRHa long protocol had high luteal blood flow impedance with very low serum LH levels. HCG administration improved luteal blood flow impedance. This suggests that luteal blood flow is regulated by LH.

Modification of Aortic Cannula With an Inlet Chamber to Induce Spiral Flow and Improve Outlet Flow.

Science.gov (United States)

Darlis, Nofrizalidris; Osman, Kahar; Padzillah, Muhamad Hasbullah; Dillon, Jeswant; Md Khudzari, Ahmad Zahran

2018-05-01

Physiologically, blood ejected from the left ventricle in systole exhibited spiral flow characteristics. This spiral flow has been proven to have several advantages such as lateral reduction of directed forces and thrombus formation, while it also appears to be clinically beneficial in suppressing neurological complications. In order to deliver spiral flow characteristics during cardiopulmonary bypass operation, several modifications have been made on an aortic cannula either at the internal or at the outflow tip; these modifications have proven to yield better hemodynamic performances compared to standard cannula. However, there is no modification done at the inlet part of the aortic cannula for inducing spiral flow so far. This study was carried out by attaching a spiral inducer at the inlet of an aortic cannula. Then, the hemodynamic performances of the new cannula were compared with the standard straight tip end-hole cannula. This is achieved by modeling the cannula and attaching the cannula at a patient-specific aorta model. Numerical approach was utilized to evaluate the hemodynamic performance, and a water jet impact experiment was used to demonstrate the jet force generated by the cannula. The new spiral flow aortic cannula has shown some improvements by reducing approximately 21% of impinging velocity near to the aortic wall, and more than 58% reduction on total force generated as compared to standard cannula. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Quantification of hepatic flow distribution using particle tracking for patient specific virtual Fontan surgery

Science.gov (United States)

Yang, Weiguang; Vignon-Clementel, Irene; Troianowski, Guillaume; Shadden, Shawn; Mohhan Reddy, V.; Feinstein, Jeffrey; Marsden, Alison

2010-11-01

The Fontan surgery is the third and final stage in a palliative series to treat children with single ventricle heart defects. In the extracardiac Fontan procedure, the inferior vena cava (IVC) is connected to the pulmonary arteries via a tube-shaped Gore-tex graft. Clinical observations have shown that the absence of a hepatic factor, carried in the IVC flow, can cause pulmonary arteriovenous malformations. Although it is clear that hepatic flow distribution is an important determinant of Fontan performance, few studies have quantified its relation to Fontan design. In this study, we virtually implanted three types of grafts (T-junction, offset and Y-graft) into 5 patient specific models of the Glenn (stage 2) anatomy. We then performed 3D time-dependent simulations and systematically compared the IVC flow distribution, energy loss, and pressure levels in different surgical designs. A robustness test is performed to evaluate the sensitivity of hepatic distribution to pulmonary flow split. Results show that the Y-graft design effectively improves the IVC flow distribution, compared to traditional designs and that surgical designs could be customized on a patient-by-patient basis.

Improved flow cytometric assessment reveals distinct microvesicle (cell-derived microparticle signatures in joint diseases.

Directory of Open Access Journals (Sweden)

Bence György

Full Text Available INTRODUCTION: Microvesicles (MVs, earlier referred to as microparticles, represent a major type of extracellular vesicles currently considered as novel biomarkers in various clinical settings such as autoimmune disorders. However, the analysis of MVs in body fluids has not been fully standardized yet, and there are numerous pitfalls that hinder the correct assessment of these structures. METHODS: In this study, we analyzed synovial fluid (SF samples of patients with osteoarthritis (OA, rheumatoid arthritis (RA and juvenile idiopathic arthritis (JIA. To assess factors that may confound MV detection in joint diseases, we used electron microscopy (EM, Nanoparticle Tracking Analysis (NTA and mass spectrometry (MS. For flow cytometry, a method commonly used for phenotyping and enumeration of MVs, we combined recent advances in the field, and used a novel approach of differential detergent lysis for the exclusion of MV-mimicking non-vesicular signals. RESULTS: EM and NTA showed that substantial amounts of particles other than MVs were present in SF samples. Beyond known MV-associated proteins, MS analysis also revealed abundant plasma- and immune complex-related proteins in MV preparations. Applying improved flow cytometric analysis, we demonstrate for the first time that CD3(+ and CD8(+ T-cell derived SF MVs are highly elevated in patients with RA compared to OA patients (p=0.027 and p=0.009, respectively, after Bonferroni corrections. In JIA, we identified reduced numbers of B cell-derived MVs (p=0.009, after Bonferroni correction. CONCLUSIONS: Our results suggest that improved flow cytometric assessment of MVs facilitates the detection of previously unrecognized disease-associated vesicular signatures.

Effectiveness of treatment with donepezil hydrochloride and changes in regional cerebral blood flow in patients with Alzheimer's disease

International Nuclear Information System (INIS)

Yoshida, Tsunetaka; Ha-Kawa, S.; Yoshimura, Masafumi; Nobuhara, Kenji; Kinoshita, Toshihiko; Sawada, Satoshi

2007-01-01

The objective of this study was to elucidate the relationship between the effects of donepezil hydrochloride (donepezil) and cerebral blood flow, and to evaluate the usefulness of cerebral blood flow imaging in assessing and predicting treatment effectiveness. The subjects were 29 outpatients (12 men and 17 women; age 50-82 years; mean age 69.2 years), who had received a diagnosis of Alzheimer's disease (AD). Efficacy was evaluated before donepezil administration; after 1 month, 3 months, and 6 months of drug administration; and at 1 year after completion of administration using the Japanese version of the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog), as a measure of cognitive function. The ADAS-cog has been frequently used to evaluate cognitive function in AD patients. Patients whose ADAS-cog scores improved by 3 or more points during the observation period were classified as responders, and those with no improvement were classified as nonresponders. 123 I-iofetamine (IMP) was used for single photon emission computed tomography cerebral blood flow scintigraphy. On the basis of ADAS-cog score improvement, 22 of the 29 patients were responders (7 men and 15 women; age 50-82 years; mean age 69.0 years) and seven were nonresponders (5 men and 2 women; age 61-80 years; mean age 70.0 years). The results indicate that a difference in cerebral blood flow responsiveness after 1 month of treatment distinguishes responders from nonresponders. After 1 month, blood flow was significantly decreased in all regions of nonresponders, whereas significant increases in blood flow were seen in the anterior frontal lobe and parietal lobe of responders. At that time point, blood flow in the basal ganglion differed significantly between the two groups, indicating that this difference in responsiveness after 1 month of treatment may distinguish responders from nonresponders. In cognitive function testing, the group that exhibited a complete response showed

Xerostomia, Hyposalivation, and Salivary Flow in Diabetes Patients.

Science.gov (United States)

López-Pintor, Rosa María; Casañas, Elisabeth; González-Serrano, José; Serrano, Julia; Ramírez, Lucía; de Arriba, Lorenzo; Hernández, Gonzalo

2016-01-01

The presence of xerostomia and hyposalivation is frequent among diabetes mellitus (DM) patients. It is not clear if the presence of xerostomia and hyposalivation is greater in DM than non-DM patients. The aims of this systematic review are (1) to compare the prevalence rates of xerostomia, (2) to evaluate the salivary flow rate, and (3) to compare the prevalence rates of hyposalivation in DM versus non-DM population. This systematic review was conducted according to the PRISMA group guidelines by performing systematic literature searches in biomedical databases from 1970 until January 18th, 2016. All studies showed higher prevalence of xerostomia in DM patients in relation to non-DM population, 12.5%-53.5% versus 0-30%. Studies that analyzed the quantity of saliva in DM population in relation to non-DM patients reported higher flow rates in non-DM than in DM patients. The variation flow rate among different studies in each group (DM/CG) is very large. Only one existing study showed higher hyposalivation prevalence in DM than non-DM patients (45% versus 2.5%). In addition, quality assessment showed the low quality of the existing studies. We recommend new studies that use more precise and current definitions concerning the determination and diagnosis of DM patients and salivary flow collection.

Improved modeling techniques for turbomachinery flow fields

Energy Technology Data Exchange (ETDEWEB)

Lakshminarayana, B. [Pennsylvania State Univ., University Park, PA (United States); Fagan, J.R. Jr. [Allison Engine Company, Indianapolis, IN (United States)

1995-10-01

This program has the objective of developing an improved methodology for modeling turbomachinery flow fields, including the prediction of losses and efficiency. Specifically, the program addresses the treatment of the mixing stress tensor terms attributed to deterministic flow field mechanisms required in steady-state Computational Fluid Dynamic (CFD) models for turbo-machinery flow fields. These mixing stress tensors arise due to spatial and temporal fluctuations (in an absolute frame of reference) caused by rotor-stator interaction due to various blade rows and by blade-to-blade variation of flow properties. These tasks include the acquisition of previously unavailable experimental data in a high-speed turbomachinery environment, the use of advanced techniques to analyze the data, and the development of a methodology to treat the deterministic component of the mixing stress tensor. Penn State will lead the effort to make direct measurements of the momentum and thermal mixing stress tensors in high-speed multistage compressor flow field in the turbomachinery laboratory at Penn State. They will also process the data by both conventional and conditional spectrum analysis to derive momentum and thermal mixing stress tensors due to blade-to-blade periodic and aperiodic components, revolution periodic and aperiodic components arising from various blade rows and non-deterministic (which includes random components) correlations. The modeling results from this program will be publicly available and generally applicable to steady-state Navier-Stokes solvers used for turbomachinery component (compressor or turbine) flow field predictions. These models will lead to improved methodology, including loss and efficiency prediction, for the design of high-efficiency turbomachinery and drastically reduce the time required for the design and development cycle of turbomachinery.

An Improved Ghost-cell Immersed Boundary Method for Compressible Inviscid Flow Simulations

KAUST Repository

Chi, Cheng

2015-05-01

This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary described using a level-set method to farther image points, incorporating a higher-order extra/interpolation scheme for the ghost cell values. In addition, a shock sensor is in- troduced to deal with image points near the discontinuities in the flow field. Adaptive mesh refinement (AMR) is used to improve the representation of the geometry efficiently. The improved ghost-cell method is validated against five test cases: (a) double Mach reflections on a ramp, (b) supersonic flows in a wind tunnel with a forward- facing step, (c) supersonic flows over a circular cylinder, (d) smooth Prandtl-Meyer expansion flows, and (e) steady shock-induced combustion over a wedge. It is demonstrated that the improved ghost-cell method can reach the accuracy of second order in L1 norm and higher than first order in L∞ norm. Direct comparisons against the cut-cell method demonstrate that the improved ghost-cell method is almost equally accurate with better efficiency for boundary representation in high-fidelity compressible flow simulations. Implementation of the improved ghost-cell method in reacting Euler flows further validates its general applicability for compressible flow simulations.

An improved ghost-cell immersed boundary method for compressible flow simulations

KAUST Repository

Chi, Cheng

2016-05-20

This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary described using a level-set method to farther image points, incorporating a higher-order extra/interpolation scheme for the ghost cell values. A sensor is introduced to deal with image points near the discontinuities in the flow field. Adaptive mesh refinement (AMR) is used to improve the representation of the geometry efficiently in the Cartesian grid system. The improved ghost-cell method is validated against four test cases: (a) double Mach reflections on a ramp, (b) smooth Prandtl-Meyer expansion flows, (c) supersonic flows in a wind tunnel with a forward-facing step, and (d) supersonic flows over a circular cylinder. It is demonstrated that the improved ghost-cell method can reach the accuracy of second order in L1 norm and higher than first order in L∞ norm. Direct comparisons against the cut-cell method demonstrate that the improved ghost-cell method is almost equally accurate with better efficiency for boundary representation in high-fidelity compressible flow simulations. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of mouthwash interventions on xerostomia and unstimulated whole saliva flow rate among hemodialysis patients: A randomized controlled study.

Science.gov (United States)

Yu, I-Chen; Tsai, Yun-Fang; Fang, Ji-Tseng; Yeh, Mei-Ming; Fang, Jia-You; Liu, Chieh-Yu

2016-11-01

Dry mouth (xerostomia) is a common symptom in hemodialysis patients, which is associated with a reduced salivary flow. Xerostomia affects patients' oral health and quality of life. The aim of this study was to investigate using a mouthwash as a means to reduce xerostomia and improve saliva flow rates in hemodialysis patients. A randomized controlled trial. Three dialysis centers in Northern Taiwan served as the study sites. Patients were purposively sampled from three hemodialysis centers in Taiwan and randomly assigned to one of three groups: pure water mouthwash; n=41, licorice mouthwash; n=44, or no mouthwash (control); n=37. The Summated Xerostomia Inventory, and unstimulated whole salivary flow rate measured dry mouth and salivary flow, respectively. Data was collected at baseline, dialysis Day 5 and Day 10. One hundred twenty-two patients participated in this study. Baselines were adjusted for any imbalances in variables and generalized estimating equations analysed the data. Compared to control, a pure water mouthwash resulted in an increase in the unstimulated salivary flow rate of 25.85×10 -3 mL/min and 25.78×10 -3 mL/min (pXerostomia Inventory scores. The licorice mouthwash also significantly improved the unstimulated salivary flow rates to 114.92×10 -3 mL/min, and 131.61×10 -3 mL/min at Day 5 and Day 10, respectively (pXerostomia Inventory (pxerostomia. This suggests the use of a licorice mouthwash may effectively relieve feelings of dry mouth in hemodialysis patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Xerostomia, Hyposalivation, and Salivary Flow in Diabetes Patients

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Rosa María López-Pintor

2016-01-01

Full Text Available The presence of xerostomia and hyposalivation is frequent among diabetes mellitus (DM patients. It is not clear if the presence of xerostomia and hyposalivation is greater in DM than non-DM patients. The aims of this systematic review are (1 to compare the prevalence rates of xerostomia, (2 to evaluate the salivary flow rate, and (3 to compare the prevalence rates of hyposalivation in DM versus non-DM population. This systematic review was conducted according to the PRISMA group guidelines by performing systematic literature searches in biomedical databases from 1970 until January 18th, 2016. All studies showed higher prevalence of xerostomia in DM patients in relation to non-DM population, 12.5%–53.5% versus 0–30%. Studies that analyzed the quantity of saliva in DM population in relation to non-DM patients reported higher flow rates in non-DM than in DM patients. The variation flow rate among different studies in each group (DM/CG is very large. Only one existing study showed higher hyposalivation prevalence in DM than non-DM patients (45% versus 2.5%. In addition, quality assessment showed the low quality of the existing studies. We recommend new studies that use more precise and current definitions concerning the determination and diagnosis of DM patients and salivary flow collection.

The effect of blood cell count on coronary flow in patients with coronary slow flow phenomenon.

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Soylu, Korhan; Gulel, Okan; Yucel, Huriye; Yuksel, Serkan; Aksan, Gokhan; Soylu, Ayşegül İdil; Demircan, Sabri; Yılmaz, Ozcan; Sahin, Mahmut

2014-09-01

The coronary slow flow phenomenon (CSFP) is a coronary artery disease with a benign course, but its pathological mechanisms are not yet fully understood.The purpose of this controlled study was to investigate the cellular content of blood in patients diagnosed with CSFP and the relationship of this with coronary flow rates. Selective coronary angiographies of 3368 patients were analyzed to assess Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) values. Seventy eight of them had CSFP, and their demographic and laboratory findings were compared with 61 patients with normal coronary flow. Patients' demographic characteristics were similar in both groups. Mean corrected TFC (cTFC) values were significantly elevated in CSFP patients (p<0.001). Furthermore, hematocrit and hemoglobin values, and eosinophil and basophil counts of the CSFP patients were significantly elevated compared to the values obtained in the control group (p=0.005, p=0.047, p=0.001 and p=0.002, respectively). The increase observed in hematocrit and eosinophil levels showed significant correlations with increased TFC values (r=0.288 and r=0.217, respectively). Significant changes have been observed in the cellular composition of blood in patients diagnosed with CSFP as compared to the patients with normal coronary blood flow. The increases in hematocrit levels and in the eosinophil and basophil counts may have direct or indirect effects on the rate of coronary blood flow.

Forecasting the Emergency Department Patients Flow.

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Afilal, Mohamed; Yalaoui, Farouk; Dugardin, Frédéric; Amodeo, Lionel; Laplanche, David; Blua, Philippe

2016-07-01

Emergency department (ED) have become the patient's main point of entrance in modern hospitals causing it frequent overcrowding, thus hospital managers are increasingly paying attention to the ED in order to provide better quality service for patients. One of the key elements for a good management strategy is demand forecasting. In this case, forecasting patients flow, which will help decision makers to optimize human (doctors, nurses…) and material(beds, boxs…) resources allocation. The main interest of this research is forecasting daily attendance at an emergency department. The study was conducted on the Emergency Department of Troyes city hospital center, France, in which we propose a new practical ED patients classification that consolidate the CCMU and GEMSA categories into one category and innovative time-series based models to forecast long and short term daily attendance. The models we developed for this case study shows very good performances (up to 91,24 % for the annual Total flow forecast) and robustness to epidemic periods.

A proactive transfer policy for critical patient flow management.

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González, Jaime; Ferrer, Juan-Carlos; Cataldo, Alejandro; Rojas, Luis

2018-02-17

Hospital emergency departments are often overcrowded, resulting in long wait times and a public perception of poor attention. Delays in transferring patients needing further treatment increases emergency department congestion, has negative impacts on their health and may increase their mortality rates. A model built around a Markov decision process is proposed to improve the efficiency of patient flows between the emergency department and other hospital units. With each day divided into time periods, the formulation estimates bed demand for the next period as the basis for determining a proactive rather than reactive transfer decision policy. Due to the high dimensionality of the optimization problem involved, an approximate dynamic programming approach is used to derive an approximation of the optimal decision policy, which indicates that a certain number of beds should be kept free in the different units as a function of the next period demand estimate. Testing the model on two instances of different sizes demonstrates that the optimal number of patient transfers between units changes when the emergency patient arrival rate for transfer to other units changes at a single unit, but remains stable if the change is proportionally the same for all units. In a simulation using real data for a hospital in Chile, significant improvements are achieved by the model in key emergency department performance indicators such as patient wait times (reduction higher than 50%), patient capacity (21% increase) and queue abandonment (from 7% down to less than 1%).

Reinventing Emergency Department Flow via Healthcare Delivery Science.

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DeFlitch, Christopher; Geeting, Glenn; Paz, Harold L

2015-01-01

Healthcare system flow resulting in emergency departments (EDs) crowding is a quality and access problem. This case study examines an overcrowded academic health center ED with increasing patient volumes and limited physical space for expansion. ED capacity and efficiency improved via engineering principles application, addressing patient and staffing flows, and reinventing the delivery model. Using operational data and staff input, patient and staff flow models were created, identifying bottlenecks (points of inefficiency). A new flow model of emergency care delivery, physician-directed queuing, was developed. Expanding upon physicians in triage, providers passively evaluate all patients upon arrival, actively manage patients requiring fewer resources, and direct patients requiring complex resources to further evaluation in ED areas. Sustained over time, ED efficiency improved as measured by near elimination of "left without being seen" patients and waiting times with improvement in door to doctor, patient satisfaction, and total length of stay. All improvements were in the setting on increased patient volume and no increase in physician staffing. Our experience suggests that practical application of healthcare delivery science can be used to improve ED efficiency. © The Author(s) 2015.

Queueing network model for obstetric patient flow in a hospital.

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Takagi, Hideaki; Kanai, Yuta; Misue, Kazuo

2016-03-03

A queueing network is used to model the flow of patients in a hospital using the observed admission rate of patients and the histogram for the length of stay for patients in each ward. A complete log of orders for every movement of all patients from room to room covering two years was provided to us by the Medical Information Department of the University of Tsukuba Hospital in Japan. We focused on obstetric patients, who are generally hospitalized at random times throughout the year, and we analyzed the patient flow probabilistically. On admission, each obstetric patient is assigned to a bed in one of the two wards: one for normal delivery and the other for high-risk delivery. Then, the patient may be transferred between the two wards before discharge. We confirm Little's law of queueing theory for the patient flow in each ward. Next, we propose a new network model of M/G/ ∞ and M/M/ m queues to represent the flow of these patients, which is used to predict the probability distribution for the number of patients staying in each ward at the nightly census time. Although our model is a very rough and simplistic approximation of the real patient flow, the predicted probability distribution shows good agreement with the observed data. The proposed method can be used for capacity planning of hospital wards to predict future patient load in each ward.

Implementation of hospital-wide reform at improving access and flow: Impact on time to antibiotics in the emergency department.

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Roman, Cristina P; Poole, Susan G; Dooley, Michael J; Smit, De Villiers; Mitra, Biswadev

2016-04-01

ED overcrowding has been associated with increased mortality, morbidity and delays to essential treatment. It was hypothesised that hospital-wide reforms designed to improve patient access and flow, in addition to improving ED overcrowding, would impact on clinically important processes within the ED, such as timely delivery of antibiotics. A single pre-implementation and post-implementation prospective cohort study was conducted prior to and after a hospital-wide reform (Timely Quality Care (TQC)). Among patients who had intravenous antibiotics prescribed in the ED, data were prospectively collected on times of presentation, prescription and administration of antibiotics. Demographics and discharge diagnoses were retrospectively extracted. There were 380 cases included with 179 cases prior to introduction of the TQC model and 201 cases after its introduction. Time from presentation to administration of antibiotics improved significantly from 192 (99-320) min to 142 (81-209) min (P antibiotics were significantly reduced. These findings suggest that improved quality of care in this area may be achieved with processes aimed at improved hospital access and flow. Ongoing evaluation and vigilance is necessary to ensure sustainability and drive further improvements. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Effects of exercise training on calf muscle oxygen extraction and blood flow in patients with peripheral artery disease.

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Baker, Wesley B; Li, Zhe; Schenkel, Steven S; Chandra, Malavika; Busch, David R; Englund, Erin K; Schmitz, Kathryn H; Yodh, Arjun G; Floyd, Thomas F; Mohler, Emile R

2017-12-01

We employed near-infrared optical techniques, diffuse correlation spectroscopy (DCS), and frequency-domain near-infrared spectroscopy (FD-NIRS) to test the hypothesis that supervised exercise training increases skeletal muscle microvascular blood flow and oxygen extraction in patients with peripheral artery disease (PAD) who experience claudication. PAD patients ( n = 64) were randomly assigned to exercise and control groups. Patients in the exercise group received 3 mo of supervised exercise training. Calf muscle blood flow and oxygen extraction were optically monitored before, during, and after performance of a graded treadmill protocol at baseline and at 3 mo in both groups. Additionally, measurements of the ankle-brachial index (ABI) and peak walking time (PWT) to maximal claudication were made during each patient visit. Supervised exercise training was found to increase the maximal calf muscle blood flow and oxygen extraction levels during treadmill exercise by 29% (13%, 50%) and 8% (1%, 12%), respectively [ P group population were significantly higher than corresponding changes in the control group ( P training also increased PWT by 49% (18%, 101%) ( P = 0.01). However, within statistical error, the ABI, resting calf muscle blood flow and oxygen extraction, and the recovery half-time for hemoglobin\\myoglobin desaturation following cessation of maximal exercise were not altered by exercise training. The concurrent monitoring of both blood flow and oxygen extraction with the hybrid DCS/FD-NIRS instrument revealed enhanced muscle oxidative metabolism during physical activity from exercise training, which could be an underlying mechanism for the observed improvement in PWT. NEW & NOTEWORTHY We report on noninvasive optical measurements of skeletal muscle blood flow and oxygen extraction dynamics before/during/after treadmill exercise in peripheral artery disease patients who experience claudication. The measurements tracked the effects of a 3-mo supervised

Improved electrolyte for zinc-bromine flow batteries

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Wu, M. C.; Zhao, T. S.; Wei, L.; Jiang, H. R.; Zhang, R. H.

2018-04-01

Conventional zinc bromide electrolytes offer low ionic conductivity and often trigger severe zinc dendrite growth in zinc-bromine flow batteries. Here we report an improved electrolyte modified with methanesulfonic acid, which not only improves the electrolyte conductivity but also ameliorates zinc dendrite. Experimental results also reveal that the kinetics and reversibility of Zn2+/Zn and Br2/Br- are improved in this modified electrolyte. Moreover, the battery's internal resistance is significantly reduced from 4.9 to 2.0 Ω cm2 after adding 1 M methanesulfonic acid, thus leading to an improved energy efficiency from 64% to 75% at a current density of 40 mA cm-2. More impressively, the battery is capable of delivering an energy efficiency of about 78% at a current density of as high as 80 mA cm-2 when the electrode is replaced by a thermally treated one. Additionally, zinc dendrite growth is found to be effectively suppressed in methanesulfonic acid supported media, which, as a result, enables the battery to be operated for 50 cycles without degradation, whereas the one without methanesulfonic acid suffers from significant decay after only 40 cycles, primarily due to severe zinc dendrite growth. These superior results indicate methanesulfonic acid is a promising supporting electrolyte for zinc-bromine flow batteries.

Physically consistent data assimilation method based on feedback control for patient-specific blood flow analysis.

Science.gov (United States)

Ii, Satoshi; Adib, Mohd Azrul Hisham Mohd; Watanabe, Yoshiyuki; Wada, Shigeo

2018-01-01

This paper presents a novel data assimilation method for patient-specific blood flow analysis based on feedback control theory called the physically consistent feedback control-based data assimilation (PFC-DA) method. In the PFC-DA method, the signal, which is the residual error term of the velocity when comparing the numerical and reference measurement data, is cast as a source term in a Poisson equation for the scalar potential field that induces flow in a closed system. The pressure values at the inlet and outlet boundaries are recursively calculated by this scalar potential field. Hence, the flow field is physically consistent because it is driven by the calculated inlet and outlet pressures, without any artificial body forces. As compared with existing variational approaches, although this PFC-DA method does not guarantee the optimal solution, only one additional Poisson equation for the scalar potential field is required, providing a remarkable improvement for such a small additional computational cost at every iteration. Through numerical examples for 2D and 3D exact flow fields, with both noise-free and noisy reference data as well as a blood flow analysis on a cerebral aneurysm using actual patient data, the robustness and accuracy of this approach is shown. Moreover, the feasibility of a patient-specific practical blood flow analysis is demonstrated. Copyright © 2017 John Wiley & Sons, Ltd.

Symptomatic relief precedes improvement of myocardial blood flow in patients under spinal cord stimulation

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Koulousakis Athanassios

2005-05-01

Full Text Available Abstract Background Spinal cord electrical stimulation (SCS has shown to be a treatment option for patients suffering from angina pectoris CCS III-IV although being on optimal medication and not suitable for conventional treatment strategies, e.g. CABG or PTCA. Although many studies demonstrated a clear symptomatic relief under SCS therapy, there are only a few short-term studies that investigated alterations in cardiac ischemia. Therefore doubts remain whether SCS has a direct effect on myocardial perfusion. Methods A prospective study to investigate the short- and long-term effect of spinal cord stimulation (SCS on myocardial ischemia in patients with refractory angina pectoris and coronary multivessel disease was designed. Myocardial ischemia was measured by MIBI-SPECT scintigraphy 3 months and 12 months after the beginning of neurostimulation. To further examine the relation between cardiac perfusion and functional status of the patients we measured exercise capacity (bicycle ergometry and 6-minute walk test, symptoms and quality of life (Seattle Angina Questionnaire [SAQ], as well. Results 31 patients (65 ± 11 SEM years; 25 male, 6 female were included into the study. The average consumption of short acting nitrates (SAN decreased rapidly from 12 ± 1.6 times to 3 ± 1 times per week. The walking distance and the maximum workload increased from 143 ± 22 to 225 ± 24 meters and 68 ± 7 to 96 ± 12 watt after 3 months. Quality of life increased (SAQ significantly after 3 month compared to baseline, as well. No further improvement was observed after one year of treament. Despite the symptomatic relief and the improvement in maximal workload computer based analysis (Emory Cardiac Toolbox of the MIBI-SPECT studies after 3 months of treatment did not show significant alterations of myocardial ischemia compared to baseline (16 patients idem, 7 with increase and 6 with decrease of ischemia, 2 patients dropped out during initial test phase

Respiratory mechanics by least squares fitting in mechanically ventilated patients: application on flow-limited COPD patients.

Science.gov (United States)

Volta, Carlo A; Marangoni, Elisabetta; Alvisi, Valentina; Capuzzo, Maurizia; Ragazzi, Riccardo; Pavanelli, Lina; Alvisi, Raffaele

2002-01-01

Although computerized methods of analyzing respiratory system mechanics such as the least squares fitting method have been used in various patient populations, no conclusive data are available in patients with chronic obstructive pulmonary disease (COPD), probably because they may develop expiratory flow limitation (EFL). This suggests that respiratory mechanics be determined only during inspiration. Eight-bed multidisciplinary ICU of a teaching hospital. Eight non-flow-limited postvascular surgery patients and eight flow-limited COPD patients. Patients were sedated, paralyzed for diagnostic purposes, and ventilated in volume control ventilation with constant inspiratory flow rate. Data on resistance, compliance, and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn) obtained by applying the least squares fitting method during inspiration, expiration, and the overall breathing cycle were compared with those obtained by the traditional method (constant flow, end-inspiratory occlusion method). Our results indicate that (a) the presence of EFL markedly decreases the precision of resistance and compliance values measured by the LSF method, (b) the determination of respiratory variables during inspiration allows the calculation of respiratory mechanics in flow limited COPD patients, and (c) the LSF method is able to detect the presence of PEEPi,dyn if only inspiratory data are used.

Quality initiatives: improving patient flow for a bone densitometry practice: results from a Mayo Clinic radiology quality initiative.

Science.gov (United States)

Aakre, Kenneth T; Valley, Timothy B; O'Connor, Michael K

2010-03-01

Lean Six Sigma process improvement methodologies have been used in manufacturing for some time. However, Lean Six Sigma process improvement methodologies also are applicable to radiology as a way to identify opportunities for improvement in patient care delivery settings. A multidisciplinary team of physicians and staff conducted a 100-day quality improvement project with the guidance of a quality advisor. By using the framework of DMAIC (define, measure, analyze, improve, and control), time studies were performed for all aspects of patient and technologist involvement. From these studies, value stream maps for the current state and for the future were developed, and tests of change were implemented. Comprehensive value stream maps showed that before implementation of process changes, an average time of 20.95 minutes was required for completion of a bone densitometry study. Two process changes (ie, tests of change) were undertaken. First, the location for completion of a patient assessment form was moved from inside the imaging room to the waiting area, enabling patients to complete the form while waiting for the technologist. Second, the patient was instructed to sit in a waiting area immediately outside the imaging rooms, rather than in the main reception area, which is far removed from the imaging area. Realignment of these process steps, with reduced technologist travel distances, resulted in a 3-minute average decrease in the patient cycle time. This represented a 15% reduction in the initial patient cycle time with no change in staff or costs. Radiology process improvement projects can yield positive results despite small incremental changes.

Interplay of Proximal Flow Confluence and Distal Flow Divergence in Patient-Specific Vertebrobasilar System.

Directory of Open Access Journals (Sweden)

Xiaoping Yin

Full Text Available Approximately one-quarter of ischemic strokes involve the vertebrobasilar arterial system that includes the upstream flow confluence and downstream flow divergence. A patient-specific hemodynamic analysis is needed to understand the posterior circulation. The objective of this study is to determine the distribution of hemodynamic parameters in the vertebrobasilar system, based on computer tomography angiography images. Here, the interplay of upstream flow confluence and downstream flow divergence was hypothesized to be a determinant factor for the hemodynamic distribution in the vertebrobasilar system. A computational fluid dynamics model was used to compute the flow fields in patient-specific vertebrobasilar models (n = 6. The inlet and outlet boundary conditions were the aortic pressure waveform and flow resistances, respectively. A 50% reduction of total outlet area was found to induce a ten-fold increase in surface area ratio of low time-averaged wall shear stress (i.e., TAWSS ≤ 4 dynes/cm2. This study enhances our understanding of the posterior circulation associated with the incidence of atherosclerotic plaques.

A single LipiFlow® Thermal Pulsation System treatment improves meibomian gland function and reduces dry eye symptoms for 9 months.

Science.gov (United States)

Greiner, Jack V

2012-04-01

To evaluate the effect of a single treatment with the LipiFlow(®) Thermal Pulsation System on signs of meibomian gland dysfunction (MGD) and dry eye symptoms over a 9-month period. Patients (n = 42 eyes, 21 subjects) diagnosed with MGD and dry eye symptoms were recruited for a non-significant risk, prospective, open-label, 1-month clinical trial. Patients received a single 12-minute treatment using the LipiFlow(®) Thermal Pulsation System on each eye. The LipiFlow(®) device applies heat to the conjunctival surfaces of the upper and lower inner eyelids while simultaneously applying pulsatile pressure to the outer eyelid surfaces to express the meibomian glands. Patient symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Standard Patient Evaluation for Eye Dryness (SPEED) dry eye questionnaires; tear break-up time was measured with the dry eye test (DET™); and meibomian gland function was evaluated using a standardized diagnostic expression technique. Data are presented for patient's pre-treatment (baseline) and at 1-month and 9-month post-treatment. Meibomian gland secretion scores improved significantly from baseline (4.4 ± 4.0) to 1-month post-treatment (11.3 ± 6.2; p dry eye disease, the LipiFlow(®) Thermal Pulsation System offers a technological advancement for the treatment of dry eye disease secondary to meibomian gland dysfunction. A single 12-minute LipiFlow(®) treatment results in up to 9 months of sustained improvement of meibomian gland function, tear break-up time and dry eye symptoms that are unparalleled with current dry eye treatments.

Patient Specific Multiscale Simulations of Blood Flow in Coronary Artery Bypass Surgery

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Bangalore Ramachandra, Abhay; Sankaran, Sethuraman; Kahn, Andrew M.; Marsden, Alison L.

2013-11-01

Coronary artery bypass surgery is performed to revascularize blocked coronary arteries in roughly 400,000 patients per year in the US.While arterial grafts offer superior patency, vein grafts are used in more than 70% of procedures, as most patients require multiple grafts. Vein graft failure (approx. 50% within 10 years) remains a major clinical issue. Mounting evidence suggests that hemodynamics plays a key role as a mechano-biological stimulus contributing to graft failure. However, quantifying relevant hemodynamic quantities (e.g. wall shear stress) invivo is not possible directly using clinical imaging techniques. We numerically compute graft hemodynamics in a cohort of 3-D patient specific models using a stabilized finite element method. The 3D flow domain is coupled to a 0D lumped parameter circulatory model. Boundary conditions are tuned to match patient specific blood pressures, stroke volumes & heart rates. Results reproduce clinically observed coronary flow waveforms. We quantify differences in multiple hemodynamic quantities between arterial & venous grafts & discuss possible correlations between graft hemodynamics & clinically observed graft failure.Such correlations will provide further insight into mechanisms of graft failure and may lead to improved clinical outcomes.

4D-MR flow analysis in patients after repair for tetralogy of Fallot

International Nuclear Information System (INIS)

Geiger, J.; Markl, M.; Jung, B.; Langer, M.; Grohmann, J.; Stiller, B.; Arnold, R.

2011-01-01

Comprehensive analysis of haemodynamics by 3D flow visualisation and retrospective flow quantification in patients after repair of tetralogy of Fallot (TOF). Time-resolved flow-sensitive 4D MRI (spatial resolution ∝ 2.5 mm, temporal resolution = 38.4 ms) was acquired in ten patients after repair of TOF and in four healthy controls. Data analysis included the evaluation of haemodynamics in the aorta, the pulmonary trunk (TP) and left (lPA) and right (rPA) pulmonary arteries by 3D blood flow visualisation using particle traces, and quantitative measurements of flow velocity. 3D visualisation of whole heart haemodynamics provided a comprehensive overview on flow pattern changes in TOF patients, mainly alterations in flow velocity, retrograde flow and pathological vortices. There was consistently higher blood flow in the rPA of the patients (rPA/lPA flow ratio: 2.6 ± 2.5 vs. 1.1 ± 0.1 in controls). Systolic peak velocity in the TP was higher in patients (1.9 m/s ± 0.7 m/s) than controls (0.9 m/s ± 0.1 m/s). 4D flow-sensitive MRI permits the comprehensive evaluation of blood flow characteristics in patients after repair of TOF. Altered flow patterns for different surgical techniques in the small patient cohort may indicate its value for patient monitoring and potentially identifying optimal surgical strategies. (orig.)

4D-MR flow analysis in patients after repair for tetralogy of Fallot

Energy Technology Data Exchange (ETDEWEB)

Geiger, J.; Markl, M.; Jung, B.; Langer, M. [University Hospital Freiburg, Department of Radiology, Medical Physics, Freiburg (Germany); Grohmann, J.; Stiller, B.; Arnold, R. [University Hospital Freiburg, Department of Congenital Heart Disease and Pediatric Cardiology, Freiburg (Germany)

2011-08-15

Comprehensive analysis of haemodynamics by 3D flow visualisation and retrospective flow quantification in patients after repair of tetralogy of Fallot (TOF). Time-resolved flow-sensitive 4D MRI (spatial resolution {proportional_to} 2.5 mm, temporal resolution = 38.4 ms) was acquired in ten patients after repair of TOF and in four healthy controls. Data analysis included the evaluation of haemodynamics in the aorta, the pulmonary trunk (TP) and left (lPA) and right (rPA) pulmonary arteries by 3D blood flow visualisation using particle traces, and quantitative measurements of flow velocity. 3D visualisation of whole heart haemodynamics provided a comprehensive overview on flow pattern changes in TOF patients, mainly alterations in flow velocity, retrograde flow and pathological vortices. There was consistently higher blood flow in the rPA of the patients (rPA/lPA flow ratio: 2.6 {+-} 2.5 vs. 1.1 {+-} 0.1 in controls). Systolic peak velocity in the TP was higher in patients (1.9 m/s {+-} 0.7 m/s) than controls (0.9 m/s {+-} 0.1 m/s). 4D flow-sensitive MRI permits the comprehensive evaluation of blood flow characteristics in patients after repair of TOF. Altered flow patterns for different surgical techniques in the small patient cohort may indicate its value for patient monitoring and potentially identifying optimal surgical strategies. (orig.)

Numerical convergence improvements for porflow unsaturated flow simulations

Energy Technology Data Exchange (ETDEWEB)

Flach, Greg [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-14

Section 3.6 of SRNL (2016) discusses various PORFLOW code improvements to increase modeling efficiency, in preparation for the next E-Area Performance Assessment (WSRC 2008) revision. This memorandum documents interaction with Analytic & Computational Research, Inc. (http://www.acricfd.com/default.htm) to improve numerical convergence efficiency using PORFLOW version 6.42 for unsaturated flow simulations.

Successful percutaneous coronary intervention significantly improves coronary sinus blood flow as assessed by transthoracic echocardiography.

Science.gov (United States)

Lyubarova, Radmila; Boden, William E; Fein, Steven A; Schulman-Marcus, Joshua; Torosoff, Mikhail

2018-06-01

Transthoracic echocardiography (TTE) has been used to assess coronary sinus blood flow (CSBF), which reflects total coronary arterial blood flow. Successful angioplasty is expected to improve coronary arterial blood flow. Changes in CSBF after percutaneous coronary intervention (PCI), as assessed by TTE, have not been systematically evaluated. TTE can be utilized to reflect increased CSBF after a successful, clinically indicated PCI. The study cohort included 31 patients (18 females, 62 ± 11 years old) referred for diagnostic cardiac catheterization for suspected coronary artery disease and possible PCI, when clinically indicated. All performed PCIs were successful, with good angiographic outcome. CSBF per cardiac cycle (mL/beat) was measured using transthoracic two-dimensional and Doppler flow imaging as the product of coronary sinus (CS) area and CS flow time-velocity integral. CSBF per minute (mL/min) was calculated as the product of heart rate and CSBF per cardiac cycle. In each patient, CSBF was assessed prospectively, before and after cardiac catheterization with and without clinically indicated PCI. Within- and between-group differences in CSBF before and after PCI were assessed using repeated measures analysis of variance. Technically adequate CSBF measurements were obtained in 24 patients (77%). In patients who did not undergo PCI, there was no significant change in CSBF (278.1 ± 344.1 versus 342.7 ± 248.5, p = 0.36). By contrast, among patients who underwent PCI, CSBF increased significantly (254.3 ± 194.7 versus 618.3 ± 358.5 mL/min, p < 0.01, p-interaction = 0.03). Other hemodynamic and echocardiographic parameters did not change significantly before and after cardiac catheterization in either treatment group. Transthoracic echocardiographic assessment can be employed to document CSBF changes after angioplasty. Future studies are needed to explore the clinical utility of this noninvasive metric.

Coronary physiological assessment combining fractional flow reserve and index of microcirculatory resistance in patients undergoing elective percutaneous coronary intervention with grey zone fractional flow reserve.

Science.gov (United States)

Niida, Takayuki; Murai, Tadashi; Yonetsu, Taishi; Kanaji, Yoshihisa; Usui, Eisuke; Matsuda, Junji; Hoshino, Masahiro; Araki, Makoto; Yamaguchi, Masao; Hada, Masahiro; Ichijyo, Sadamitsu; Hamaya, Rikuta; Kanno, Yoshinori; Isobe, Mitsuaki; Kakuta, Tsunekazu

2018-03-08

The aim of this study is to investigate the association between fractional flow reserve (FFR) values and change in coronary physiological indices after elective percutaneous coronary intervention (PCI). Decision making for revascularization when FFR is 0.75-0.80 is controversial. A retrospective analysis was performed of 296 patients with stable angina pectoris who underwent physiological examinations before and after PCI. To investigate the differences of coronary flow improvement between territories with low-FFR (zone FFR (0.75-0.80), serial changes in physiological indices including mean transit time (Tmn), coronary flow reserve (CFR), and index of microcirculatory resistance (IMR) were compared between these two groups. Compared to low-FFR territories, grey-zone FFR territories showed significantly lower prevalence of Tmn shortening, CFR improvement, and decrease in IMR (Tmn shorting, 63.9% vs. 87.0%, P 51.3% vs. 63.3%, P = .040) and lower extent of their absolute changes (Tmn shorting, 0.06 (-0.03 to 0.16) vs. 0.22 (0.07-0.45), P zone FFR. Physiological assessment combining FFR and IMR may help identify patients who may benefit by PCI, particularly those in the grey zone. © 2018 Wiley Periodicals, Inc.

An improved mechanistic critical heat flux model for subcooled flow boiling

Energy Technology Data Exchange (ETDEWEB)

Kwon, Young Min [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1998-12-31

Based on the bubble coalescence adjacent to the heated wall as a flow structure for CHF condition, Chang and Lee developed a mechanistic critical heat flux (CHF) model for subcooled flow boiling. In this paper, improvements of Chang-Lee model are implemented with more solid theoretical bases for subcooled and low-quality flow boiling in tubes. Nedderman-Shearer`s equations for the skin friction factor and universal velocity profile models are employed. Slip effect of movable bubbly layer is implemented to improve the predictability of low mass flow. Also, mechanistic subcooled flow boiling model is used to predict the flow quality and void fraction. The performance of the present model is verified using the KAIST CHF database of water in uniformly heated tubes. It is found that the present model can give a satisfactory agreement with experimental data within less than 9% RMS error. 9 refs., 5 figs. (Author)

An improved mechanistic critical heat flux model for subcooled flow boiling

Energy Technology Data Exchange (ETDEWEB)

Kwon, Young Min [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1997-12-31

Based on the bubble coalescence adjacent to the heated wall as a flow structure for CHF condition, Chang and Lee developed a mechanistic critical heat flux (CHF) model for subcooled flow boiling. In this paper, improvements of Chang-Lee model are implemented with more solid theoretical bases for subcooled and low-quality flow boiling in tubes. Nedderman-Shearer`s equations for the skin friction factor and universal velocity profile models are employed. Slip effect of movable bubbly layer is implemented to improve the predictability of low mass flow. Also, mechanistic subcooled flow boiling model is used to predict the flow quality and void fraction. The performance of the present model is verified using the KAIST CHF database of water in uniformly heated tubes. It is found that the present model can give a satisfactory agreement with experimental data within less than 9% RMS error. 9 refs., 5 figs. (Author)

Guiding Inspiratory Flow: Development of the In-Check DIAL G16, a Tool for Improving Inhaler Technique

Directory of Open Access Journals (Sweden)

Mark Jeremy Sanders

2017-01-01

Full Text Available Portable inhalers are divisible into those that deliver medication by patient triggering (pMDIs: a gentle slow inhalation and those that use the patient’s inspiratory effort as the force for deaggregation and delivery (DPIs: a stronger deeper inspiratory effort. Patient confusion and poor technique are commonplace. The use of training tools has become standard practice, and unique amongst these is an inspiratory flow meter (In-Check which is able to simulate the resistance characteristics of different inhalers and, thereby, guide the patient to the correct effort. In-Check’s origins lie in the 1960s peak expiratory flow meters, the development of the Mini-Wright peak flow meter, and inspiratory flow assessment via the nose during the 1970s–1980s. The current device (In-Check DIAL G16 is the third iteration of the original 1998 training tool, with detailed and ongoing assessments of all common inhaler resistances (including combination and breath-actuated inhaler types summarised into resistance ranges that are preset within the device. The device works by interpolating one of six ranges with the inspiratory effort. Use of the tool has been shown to be contributory to significant improvements in asthma care and control, and it is being advocated for assessment and training in irreversible lung disease.

Improving sensitivity in micro-free flow electrophoresis using signal averaging

Science.gov (United States)

Turgeon, Ryan T.; Bowser, Michael T.

2009-01-01

Microfluidic free-flow electrophoresis (μFFE) is a separation technique that separates continuous streams of analytes as they travel through an electric field in a planar flow channel. The continuous nature of the μFFE separation suggests that approaches more commonly applied in spectroscopy and imaging may be effective in improving sensitivity. The current paper describes the S/N improvements that can be achieved by simply averaging multiple images of a μFFE separation; 20–24-fold improvements in S/N were observed by averaging the signal from 500 images recorded for over 2 min. Up to an 80-fold improvement in S/N was observed by averaging 6500 images. Detection limits as low as 14 pM were achieved for fluorescein, which is impressive considering the non-ideal optical set-up used in these experiments. The limitation to this signal averaging approach was the stability of the μFFE separation. At separation times longer than 20 min bubbles began to form at the electrodes, which disrupted the flow profile through the device, giving rise to erratic peak positions. PMID:19319908

Interprofessional simulation to improve patient participation in transitional care.

Science.gov (United States)

Dyrstad, Dagrunn Nåden; Storm, Marianne

2017-06-01

Educating and training healthcare professionals is known to improve the quality of transitional care for older adults. Arranging interprofessional meetings for healthcare professionals might be useful to improve patient participation skills in transitional care. To describe the learning activities used in The Meeting Point programme, focusing on patient participation in transitional care, and assess whether they increase healthcare professionals' awareness of and competencies relating to patient participation in the transitional care of older patients. Data were collected as part of an educational intervention programme, The Meeting Point, including three seminars on 'Patient participation in the transitional care of older patients' and four follow-up meetings. Participants were nurses, care assistants, doctors, physiotherapists, patient coordinators and administrative personnel from hospital, nursing homes and home-based care services. The Meeting Point was organised around four pillars: introduction, teaching session, group work activity and plenary discussion. Qualitative data included log reports, summaries of meetings, notes from group work activities, and reports from participants and from follow-up meetings. Feedback from participants shows that they were satisfied with meeting healthcare professionals from other units of care. A film scenario was perceived relevant for group work activity and useful in focusing participants' attention to patient participation. Follow-up meetings show that some nursing home wards, the emergency department and one medical ward at the hospital continued with ongoing work to improve quality of care. Efforts included implementation of an observational waiting room with comfortable chairs, planning for discharge in hospital admission, a daily patient flow registration system and motivational interviewing during admission to nursing home. The description of the learning activities used at The Meeting Point seminars shows that they

IMPROVING PATIENT SAFETY:

DEFF Research Database (Denmark)

Bagger, Bettan; Taylor Kelly, Hélène; Hørdam, Britta

Improving patient safety is both a national and international priority as millions of patients Worldwide suffer injury or death every year due to unsafe care. University College Zealand employs innovative pedagogical approaches in educational design. Regional challenges related to geographic......, social and cultural factors have resulted in a greater emphasis upon digital technology. Attempts to improve patient safety by optimizing students’ competencies in relation to the reporting of clinical errors, has resulted in the development of an interdisciplinary e-learning concept. The program makes...

Introduction of a Surgical Navigator in the Perioperative Process Improves Patient Satisfaction

Directory of Open Access Journals (Sweden)

Brett G Marshall

2017-03-01

Full Text Available Background: Patients who had received surgical services at Bellin Hospital reported anxiety with the surgical flow. This study tested the hypothesis that the introduction of a surgical navigator, someone who guided the patient and their accompanying others throughout the surgical process, would improve patient satisfaction. Methods: Ambulatory surgical patients were randomized to control and study groups. The study group patients were assigned a surgical navigator. Prior to discharge from the hospital, patients were asked to complete a patient satisfaction survey. Results: The study group had significantly higher mean scores (P value ≤ 0.026, top box scores (P value ≤ 0.021, and positive comments. Conclusion: The addition of a surgical navigator to the perioperative process significantly enhanced patient satisfaction in ambulatory surgical patients.

A protective role of early collateral blood flow in patients with ST-segment elevation myocardial infarction.

Science.gov (United States)

Kim, Eun Kyoung; Choi, Jin-Ho; Song, Young Bin; Hahn, Joo-Yong; Chang, Sung-A; Park, Sung-Ji; Lee, Sang-Chol; Choi, Seung-Hyuk; Choe, Yeon Hyeon; Park, Seung Woo; Gwon, Hyeon-Cheol

2016-01-01

Conflict persists regarding whether the presence of early collateral blood flow to the infarct-related artery has an effective role in reducing infarct size and improving myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate the impact of the collateral circulation on myocardial salvage and infarct size in STEMI patients. In 306 patients who were diagnosed with STEMI and underwent cardiac magnetic resonance within 1 week after revascularization, initial collateral flow to the infarct-related artery was assessed by coronary angiography. Using cardiac magnetic resonance imaging, myocardial infarct size and salvage were measured. Among 247 patients with preprocedural Thrombolysis in Myocardial Infarction flow 0/1, 54 (22%) patients had good collaterals (Rentrop grade ≥ 2, Collateral Connection Score ≥ 2). Infarct size and area at risk were significantly smaller in patients with good collaterals than those with poor collaterals (infarct size: 17.1 ± 10.1 %LV vs 21.8 ± 10.5 %LV, P = .003, area at risk: 33.8 ± 16.8 %LV vs 38.8 ± 15.5 %LV, P = .039). There was a significant difference of myocardial salvage index between 2 groups (50.9% ± 15.0% vs 43.8% ± 18.5%, P = .005). Poor collateralization was an independent predictor for large infarct size (odd ratio 2.48 [1.28-4.80], P = .007). In patients with STEMI, the presence of well-developed collaterals to occluded coronary artery from the noninfarct vessel and its extent were independently associated with reduced infarct burden and improved myocardial salvage. Our results help explain why MI patients with well-developed collateralization have reduced mortality and morbidity. Copyright © 2015 Elsevier Inc. All rights reserved.

Do water-saving technologies improve environmental flows?

Science.gov (United States)

Batchelor, Charles; Reddy, V. Ratna; Linstead, Conor; Dhar, Murli; Roy, Sumit; May, Rebecca

2014-10-01

Water saving and conservation technologies (WCTs) have been promoted widely in India as a practical means of improving the water use efficiency and freeing up water for other uses (e.g. for maintaining environmental flows in river systems). However, there is increasing evidence that, somewhat paradoxically, WCTs often contribute to intensification of water use by irrigated and rainfed farming systems. This occurs when: (1) Increased crop yields are coupled with increased consumptive water use and/or (2) Improved efficiency, productivity and profitability encourages farmers to increase the area cropped and/or to adopt multiple cropping systems. In both cases, the net effect is an increase in annual evapotranspiration that, particularly in areas of increasing water scarcity, can have the trade-off of reduced environmental flows. Recognition is also increasing that the claimed water savings of many WCTs may have been overstated. The root cause of this problem lies in confusion over what constitutes real water saving at the system or basin scales. The simple fact is that some of the water that is claimed to be ‘saved’ by WCTs would have percolated into the groundwater from where it can be and often is accessed and reused. Similarly, some of the “saved” runoff can be used downstream by, for example, farmers or freshwater ecosystems. This paper concludes that, particularly in areas facing increasing water scarcity, environmental flows will only be restored and maintained if they are given explicit (rather than theoretical or notional) attention. With this in mind, a simple methodology is proposed for deciding when and where WCTs may have detrimental impacts on environmental flows.

Sub-piexl methods for improving vector quality in echo PIV flow, imaging technology.

Science.gov (United States)

Niu, Lili; Wang, Jing; Qian, Ming; Zheng, Hairong

2009-01-01

Developments of many cardiovascular problems have been shown to have a close relationship with arterial flow conditions. An ultrasound-based particle image velocimetry technique(Echo PIV) was recently developed to measure multi-component velocity vectors and local shear rates in arteries and opaque fluid flows by identifying and tracking flow tracers (ultrasound contrast microbubbles) within these flow fields. To improve the measurement accuracy, sub-pixel calculation method was adopted in this paper to maximize the ultrasound RF signal and B mode image correlation accuracy and increase the image spatial resolution. This algorithm is employed in processing both computer-generated particle image patterns and the B-mode images of microbubbles in rotating flows obtained by a high frame rate (up to 1000 frames per second) ultrasound imaging system. The results show the correlation of particle patterns and individual flow vector quality are improved and the overall flow mappings are also improved significantly. This would help the Echo PIV system to provide better multi-component velocity accuracy.

Improved sensitivity and limit-of-detection of lateral flow devices using spatial constrictions of the flow-path.

Science.gov (United States)

Katis, Ioannis N; He, Peijun J W; Eason, Robert W; Sones, Collin L

2018-05-03

We report on the use of a laser-direct write (LDW) technique that allows the fabrication of lateral flow devices with enhanced sensitivity and limit of detection. This manufacturing technique comprises the dispensing of a liquid photopolymer at specific regions of a nitrocellulose membrane and its subsequent photopolymerisation to create impermeable walls inside the volume of the membrane. These polymerised structures are intentionally designed to create fluidic channels which are constricted over a specific length that spans the test zone within which the sample interacts with pre-deposited reagents. Experiments were conducted to show how these constrictions alter the fluid flow rate and the test zone area within the constricted channel geometries. The slower flow rate and smaller test zone area result in the increased sensitivity and lowered limit of detection for these devices. We have quantified these via the improved performance of a C-Reactive Protein (CRP) sandwich assay on our lateral flow devices with constricted flow paths which demonstrate an improvement in its sensitivity by 62x and in its limit of detection by 30x when compared to a standard lateral flow CRP device. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

LEAN SIX SIGMA TECHNIQUES TO IMPROVE OPHTHALMOLOGY CLINIC EFFICIENCY.

Science.gov (United States)

Ciulla, Thomas A; Tatikonda, Mohan V; ElMaraghi, Yehya A; Hussain, Rehan M; Hill, Amanda L; Clary, Julie M; Hattab, Eyas

2017-07-18

Ophthalmologists serve an increasing volume of a growing elderly population undergoing increasingly complex outpatient medical care, including extensive diagnostic testing and treatment. The resulting prolonged patient visit times ("patient flow times") limit quality, patient and employee satisfaction, and represent waste. Lean Six Sigma process improvement was used in a vitreoretinal practice to decrease patient flow time, demonstrating that this approach can yield significant improvement in health care. Process flow maps were created to determine the most common care pathways within clinic. Three months' visits from the electronic medical record system, which tracks patient task times at each process step in the office were collected. Care tasks and care pathways consuming the greatest time and variation were identified and modified. Follow-up analysis from 6 weeks' visits was conducted to assess improvement. Nearly all patients took one of five paths through the office. Patient flow was redesigned to reduce waiting room time by having staff members immediately start patients into one of those five paths; staffing was adjusted to address high demand tasks, and scheduling was optimized around derived predictors of patient flow times. Follow-up analysis revealed a statistically significant decline in mean patient flow time by 18% and inpatient flow time SD by 4.6%. Patient and employee satisfaction scores improved. Manufacturing industry techniques, such as Lean and Six Sigma, can be used to improve patient care, minimize waste, and enhance patient and staff satisfaction in outpatient clinics.

Cavitation performance improvement of high specific speed mixed-flow pump

International Nuclear Information System (INIS)

Chen, T; Sun, Y B; Wu, D Z; Wang, L Q

2012-01-01

Cavitation performance improvement of large hydraulic machinery such as pump and turbine has been a hot topic for decades. During the design process of the pumps, in order to minimize size, weight and cost centrifugal and mixed-flow pump impellers are required to operate at the highest possible rotational speed. The rotational speed is limited by the phenomenon of cavitation. The hydraulic model of high-speed mixed-flow pump with large flow rate and high pumping head, which was designed based on the traditional method, always involves poor cavitation performance. In this paper, on the basis of the same hydraulic design parameters, two hydraulic models of high-speed mixed-flow pump were designed by using different methods, in order to investigate the cavitation and hydraulic performance of the two models, the method of computational fluid dynamics (CFD) was adopted for internal flow simulation of the high specific speed mixed-flow pump. Based on the results of numerical simulation, the influences of impeller parameters and three-dimensional configuration on pressure distribution of the blades' suction surfaces were analyzed. The numerical simulation results shows a better pressure distribution and lower pressure drop around the leading edge of the improved model. The research results could provide references to the design and optimization of the anti-cavitation blade.

Improving patient access to an interventional US clinic.

Science.gov (United States)

Steele, Joseph R; Clarke, Ryan K; Terrell, John A; Brightmon, Tonya R

2014-01-01

A continuous quality improvement project was conducted to increase patient access to a neurointerventional ultrasonography (US) clinic. The clinic was experiencing major scheduling delays because of an increasing patient volume. A multidisciplinary team was formed that included schedulers, medical assistants, nurses, technologists, and physicians. The team created an Ishikawa diagram of the possible causes of the long wait time to the next available appointment and developed a flowchart of the steps involved in scheduling and completing a diagnostic US examination and biopsy. The team then implemented a staged intervention that included adjustments to staffing and room use (stage 1); new procedures for scheduling same-day add-on appointments (stage 2); and a lead technician rotation to optimize patient flow, staffing, and workflow (stage 3). Six months after initiation of the intervention, the mean time to the next available appointment had decreased from 25 days at baseline to 1 day, and the number of available daily appointments had increased from 38 to 55. These improvements resulted from a coordinated provider effort and had a net present value of more than $275,000. This project demonstrates that structural changes in staffing, workflow, and room use can substantially reduce scheduling delays for critical imaging procedures. © RSNA, 2014.

Altered doppler flow patterns in cirrhosis patients: An overview

Energy Technology Data Exchange (ETDEWEB)

Iranpour, Pooya; Lall, Chandana; Houshyar, Roozbeh; Helmy, Mohammad; Yang, Albert; Ward, Garrett; Goodwin, Scott C. [Dept. of Radiology, University of California Irvine, Orange (United States); Choi, Joon Il [Dept. of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

2016-01-15

Doppler ultrasonography of the hepatic vasculature is an integral part of evaluating precirrhotic and cirrhotic patients. While the reversal of the portal venous flow is a well-recognized phenomenon, other flow patterns, although not as easily understood, may play an important role in assessing the disease status. This article discusses the different characteristic flow patterns observed from the portal vein, hepatic artery, and hepatic vein in patients with liver cirrhosis or related complications and procedures. Knowledge of these different flow patterns provides additional information that may reinforce the diagnosis of cirrhosis, help in staging, and offer prognostic information for determining the direction of therapy. Doppler ultrasonography is invaluable when liver transplantation is being considered and aids in the diagnosis of cirrhosis and portal hypertension.

The Akzo-Fina cold flow improvement process

Energy Technology Data Exchange (ETDEWEB)

Free, H.W.H.; Schockaert, T.; Sonnemans, J.W.M. (Akzo Chemicals B.V., Amersfoort (Netherlands). Hydroprocessing Catalysts)

1993-09-01

The Akzo-Fina CFI process is a very flexible process in which improvement of cold flow properties, desulfurization and hydroconversion are achieved. One of the main characteristics is the dewaxing obtained by the selective hydrocracking of normal paraffins combined with hydro-desulfurization and hydroconversion. Since its introduction in 1988, five licenses have been sold. The units currently run for heavy gasoil upgrading show an excellent performance and reach pour point improvements of over 50[degree]C, long cycle lengths and product sulfur levels well below 0.05 wt%. 2 figs., 2 tabs.

Researchers' Roles in Patient Safety Improvement.

Science.gov (United States)

Pietikäinen, Elina; Reiman, Teemu; Heikkilä, Jouko; Macchi, Luigi

2016-03-01

In this article, we explore how researchers can contribute to patient safety improvement. We aim to expand the instrumental role researchers have often occupied in relation to patient safety improvement. We reflect on our own improvement model and experiences as patient safety researchers in an ongoing Finnish multi-actor innovation project through self-reflective narration. Our own patient safety improvement model can be described as systemic. Based on the purpose of the innovation project, our improvement model, and the improvement models of the other actors in the project, we have carried out a wide range of activities. Our activities can be summarized in 8 overlapping patient safety improvement roles: modeler, influencer, supplier, producer, ideator, reflector, facilitator, and negotiator. When working side by side with "practice," researchers are offered and engage in several different activities. The way researchers contribute to patient safety improvement and balance between different roles depends on the purpose of the study, as well as on the underlying patient safety improvement models. Different patient safety research paradigms seem to emphasize different improvement roles, and thus, they also face different challenges. Open reflection on the underlying improvement models and roles can help researchers with different backgrounds-as well as other actors involved in patient safety improvement-in structuring their work and collaborating productively.

Improving urban wind flow predictions through data assimilation

Science.gov (United States)

Sousa, Jorge; Gorle, Catherine

2017-11-01

Computational fluid dynamic is fundamentally important to several aspects in the design of sustainable and resilient urban environments. The prediction of the flow pattern for example can help to determine pedestrian wind comfort, air quality, optimal building ventilation strategies, and wind loading on buildings. However, the significant variability and uncertainty in the boundary conditions poses a challenge when interpreting results as a basis for design decisions. To improve our understanding of the uncertainties in the models and develop better predictive tools, we started a pilot field measurement campaign on Stanford University's campus combined with a detailed numerical prediction of the wind flow. The experimental data is being used to investigate the potential use of data assimilation and inverse techniques to better characterize the uncertainty in the results and improve the confidence in current wind flow predictions. We consider the incoming wind direction and magnitude as unknown parameters and perform a set of Reynolds-averaged Navier-Stokes simulations to build a polynomial chaos expansion response surface at each sensor location. We subsequently use an inverse ensemble Kalman filter to retrieve an estimate for the probabilistic density function of the inflow parameters. Once these distributions are obtained, the forward analysis is repeated to obtain predictions for the flow field in the entire urban canopy and the results are compared with the experimental data. We would like to acknowledge high-performance computing support from Yellowstone (ark:/85065/d7wd3xhc) provided by NCAR.

Method and apparatus for improved melt flow during continuous strip casting

Science.gov (United States)

Follstaedt, Donald W.; King, Edward L.; Schneider, Ken C.

1991-11-12

The continuous casting of metal strip using the melt overflow process is improved by controlling the weir conditions in the nozzle to provide a more uniform flow of molten metal across the width of the nozzle and reducing the tendency for freezing of metal along the interface with refractory surfaces. A weir design having a sloped rear wall and tapered sidewalls and critical gap controls beneath the weir has resulted in the drastic reduction in edge tearing and a significant improvement in strip uniformity. The floor of the container vessel is preferably sloped and the gap between the nozzle and the rotating substrate is critically controlled. The resulting flow patterns observed with the improved casting process have reduced thermal gradients in the bath, contained surface slag and eliminated undesirable solidification near the discharge area by increasing the flow rates at those points.

Patients Provide Recommendations for Improving Patient Satisfaction.

Science.gov (United States)

Moore, Angelo D; Hamilton, Jill B; Krusel, Jessica L; Moore, LeeAntoinette G; Pierre-Louis, Bosny J

2016-04-01

National Committee for Quality Assurance recommends patient-centered medical homes incorporate input from patient populations; however, many health care organizations do not. This qualitative study used two open-ended questions from 148 active duty Army Soldiers and their family members to illicit recommendations for primary care providers and clinic leadership that would improve their health care experiences. Content analysis and descriptive statistics were used to analyze responses. Participant responses were related to four major themes: Access to Care, Interpersonal Interaction, Satisfaction of Care, and Quality of Care. Participants were overall satisfied with their care; however, spending less time waiting for appointments and to see the provider or specialist were the most frequently requested improvements related to Access to Care. For Interpersonal Interaction, 82% of the responses recommended that providers be more attentive listeners, courteous, patient, caring, and respectful. Decreasing wait times and improving interpersonal skills would improve health care experiences and patient satisfaction. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Increasing Throughput: Results from a 42-Hospital Collaborative to Improve Emergency Department Flow.

Science.gov (United States)

Zocchi, Mark S; McClelland, Mark S; Pines, Jesse M

2015-12-01

An 18-month collaborative in 42 hospitals across 16 communities in the United States to improve emergency department (ED) flow was conducted from October 2010 through March 2012. Hospitals were invited to participate through the Aligning Forces for Quality (AF4Q) program. Each participating hospital identified one or more interventions to improve ED flow and submitted data on four measures of ED flow: discharged length of stay (LOS), admitted LOS, boarding time, and left without being seen (LWBS) rates. Participating hospitals also provided quarterly progress reports on challenges encountered and lessons learned. Univariate linear regression was used to assess the effectiveness of interventions at the hospital level, where an improvement was defined as a negative slope in one or more of the throughput indicators. Challenges and lessons learned were tabulated and described. A total of 172 interventions were implemented across the 42 hospitals. Two thirds (n = 28) demonstrated improvement on at least one measure of ED flow. Among hospitals demonstrating improvement, the average reduction in discharged LOS was 26 minutes (95% confidence interval [CI] 11 to 41); admitted LOS, 36.5 minutes (95% CI 20 to 53), boarding time, 20.9 minutes (95% CI 12 to 30), and LWBS seen rates decreased by 1.4 absolute percentage points (95% CI 0.2 to 2.7). Teams were frequently challenged by issues related to leadership, staff buy-in, and resource constraints. The majority of hospitals in this collaborative improved on one or more ED flow measures. Many challenges were shared across hospitals, demonstrating that successful approaches to ED flow improvement require certain fundamental elements, including engaged leadership and staff, and sufficient resources.

Renal embolic protection devices improve blood flow after stenting for atherosclerotic renal artery stenosis.

Science.gov (United States)

Paul, Timir K; Lee, John H; White, Christopher J

2012-11-15

We sought to measure angiographic renal frame counts (RFC), as a quantitative angiographic assessment of renal blood flow, to evaluate microvascular compromise due to atheroembolism associated with RAS. Atheroembolism associated with renal artery stenting (RAS) has been implicated as a cause for worsening renal function following successful intervention. Use of a distal embolic protection device (EPD) during RAS has been shown to be safe with debris capture in a high percentage of cases. However, objective benefit for renal function with EPD has been difficult to demonstrate. A control group of 30 consecutive patients (33 kidneys) who underwent RAS without EPD were compared with 33 consecutive patients (33 kidneys) who underwent RAS with EPD using RFC measurement. The prestent and poststent mean RFC for the control group was 30.4 ± 12.1 vs. 23.7 ± 9.9 (P = 0.002) and for the EPD group it was 42.6 ± 12.6 vs. 28.3 ± 9.2 (P renal blood flow, manifested by a greater reduction of the RFC (Δ RFC) 14.2 ± 15.2 vs. 6.7 ± 11.7 (P = 0.03) compared with the control group. The use of an EPD was associated with a much larger improvement in renal blood flow (lower RFC) following RAS. This suggests that EPD's may be effective in preventing renal atheroembolic injury and that a controlled trial measuring the impact of EPD's on renal blood flow following RAS should be performed. Copyright © 2012 Wiley Periodicals, Inc.

[Effects of therapeutic complexes including balneoradonokinesitherapy, electromyostimulation and low-frequency magnetotherapy on regional blood flow in patients with postrraumatic gonarthritis].

Science.gov (United States)

Raspopova, E A; Udartsev, E Iu

2006-01-01

Balneoradonokinesitherapy alone and its combination with electrostimulation and low-frequency magnetotherapy were used for the treatment of regional blood flow disorders in 76 patients with posttraumatic gonarthritis. Balneoradonokinesitherapy in combination with electromyostimulation improved blood circulation. When low-frequency magnetotherapy was added to the latter complex, the regress of regional blood flow disorders of a damaged extremity was most significant.

Use of high-flow nasal cannula in obese patients receiving colonoscopy under intravenous propofol sedation: A case series

Directory of Open Access Journals (Sweden)

Chi Chan Lee

Full Text Available Intravenous sedation during colonoscopy has become the standard practice in the United States given its higher patient satisfaction and procedural quality. This practice is not free of side effects as a significant proportion of patients undergoing this procedure tend to have respiratory depression and desaturation events. Obesity, as it relates to higher levels of body mass index (BMI has a positive correlation with the incidence of hypoxemia. During colonoscopy High flow nasal cannula (HFNC may potentially improve oxygen performance in patients receiving colonoscopy under intravenous sedation. Here we present 3 cases of patients undergoing adjunctive oxygen therapy with HFNC during colonoscopy with intravenous sedation. We found patients to have lower number of desaturation events and were satisfied with their experience. Keywords: High BMI (body mass index, HFNC (high-flow nasal cannula, Colonoscopy, Intravenous sedation, Obesity

Restructuring patient flow logistics around patient care needs: implications and practicalities from three critical cases.

Science.gov (United States)

Villa, Stefano; Barbieri, Marta; Lega, Federico

2009-06-01

To make hospitals more patient-centered it is necessary to intervene on patient flow logistics. The study analyzes three innovative redesign projects implemented at three Italian hospitals. The three hospitals have reorganized patient flow logistics around patient care needs using, as proxies, the expected length of stay and the level of nursing assistance. In order to do this, they have extensively revised their logistical configuration changing: (1) the organization of wards, (2) the hospital's physical lay-out, (3) the capacity planning system, and (4) the organizational roles supporting the patient flow management. The study describes the changes implemented as well as the results achieved and draws some general lessons that provide useful hints for those other hospitals involved in such type of redesign projects. The paper ends by discussing some policy implications. In fact, the results achieved in the three cases investigated provide interesting material for further discussion on clinical, operational, and economic issues.

Improvements in Low-cost Ultrasonic Measurements of Blood Flow in "by-passes" Using Narrow & Broad Band Transit-time Procedures

Science.gov (United States)

Ramos, A.; Calas, H.; Diez, L.; Moreno, E.; Prohías, J.; Villar, A.; Carrillo, E.; Jiménez, A.; Pereira, W. C. A.; Von Krüger, M. A.

The cardio-pathology by ischemia is an important cause of death, but the re-vascularization of coronary arteries (by-pass operation) is an useful solution to reduce associated morbidity improving quality of life in patients. During these surgeries, the flow in coronary vessels must be measured, using non-invasive ultrasonic methods, known as transit time flow measurements (TTFM), which are the most accurate option nowadays. TTFM is a common intra-operative tool, in conjunction with classic Doppler velocimetry, to check the quality of these surgery processes for implanting grafts in parallel with the coronary arteries. This work shows important improvements achieved in flow-metering, obtained in our research laboratories (CSIC, ICIMAF, COPPE) and tested under real surgical conditions in Cardiocentro-HHA, for both narrowband NB and broadband BB regimes, by applying results of a CYTED multinational project (Ultrasonic & computational systems for cardiovascular diagnostics). mathematical models and phantoms were created to evaluate accurately flow measurements, in laboratory conditions, before our new electronic designs and low-cost implementations, improving previous ttfm systems, which include analogic detection, acquisition & post-processing, and a portable PC. Both regimes (NB and BB), with complementary performances for different conditions, were considered. Finally, specific software was developed to offer facilities to surgeons in their interventions.

Efficacy of high-flow oxygen by nasal cannula with active humidification in a patient with acute respiratory failure of neuromuscular origin.

Science.gov (United States)

Díaz-Lobato, Salvador; Folgado, Miguel Angel; Chapa, Angel; Mayoralas Alises, Sagrario

2013-12-01

The treatment of choice for patients with respiratory failure of neuromuscular origin, especially in patients with hypercapnic respiratory acidosis, is noninvasive ventilation (NIV). Endotracheal intubation and invasive ventilation are indicated for patients with severe respiratory compromise or failure of NIV. In recent years, high-flow oxygen therapy and active humidification devices have been introduced, and emerging evidence suggests that high-flow oxygen may be effective in various clinical settings, such as acute respiratory failure, after cardiac surgery, during sedation and analgesia, in acute heart failure, in hypoxemic respiratory distress, in do-not-intubate patients, in patients with chronic cough and copious secretions, pulmonary fibrosis, or cancer, in critical areas and the emergency department. We report on a patient with amyotrophic lateral sclerosis who arrived at the emergency department with acute hypercapnic respiratory failure. She did not tolerate NIV and refused intubation, but was treated successfully with heated, humidified oxygen via high-flow nasal cannula. Arterial blood analysis after an hour on high-flow nasal cannula showed improved pH, P(aCO2), and awareness. The respiratory acidosis was corrected, and she was discharged after 5 days of hospitalization. Her response to high-flow nasal cannula was similar to that expected with NIV. We discuss the mechanisms of action of heated, humidified high-flow oxygen therapy.

A universal deep learning approach for modeling the flow of patients under different severities.

Science.gov (United States)

Jiang, Shancheng; Chin, Kwai-Sang; Tsui, Kwok L

2018-02-01

The Accident and Emergency Department (A&ED) is the frontline for providing emergency care in hospitals. Unfortunately, relative A&ED resources have failed to keep up with continuously increasing demand in recent years, which leads to overcrowding in A&ED. Knowing the fluctuation of patient arrival volume in advance is a significant premise to relieve this pressure. Based on this motivation, the objective of this study is to explore an integrated framework with high accuracy for predicting A&ED patient flow under different triage levels, by combining a novel feature selection process with deep neural networks. Administrative data is collected from an actual A&ED and categorized into five groups based on different triage levels. A genetic algorithm (GA)-based feature selection algorithm is improved and implemented as a pre-processing step for this time-series prediction problem, in order to explore key features affecting patient flow. In our improved GA, a fitness-based crossover is proposed to maintain the joint information of multiple features during iterative process, instead of traditional point-based crossover. Deep neural networks (DNN) is employed as the prediction model to utilize their universal adaptability and high flexibility. In the model-training process, the learning algorithm is well-configured based on a parallel stochastic gradient descent algorithm. Two effective regularization strategies are integrated in one DNN framework to avoid overfitting. All introduced hyper-parameters are optimized efficiently by grid-search in one pass. As for feature selection, our improved GA-based feature selection algorithm has outperformed a typical GA and four state-of-the-art feature selection algorithms (mRMR, SAFS, VIFR, and CFR). As for the prediction accuracy of proposed integrated framework, compared with other frequently used statistical models (GLM, seasonal-ARIMA, ARIMAX, and ANN) and modern machine models (SVM-RBF, SVM-linear, RF, and R-LASSO), the

Effect of STA-proximal MCA bypass. Improvement of cerebral blood flow and metabolism and neuropsychological function

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Akira; Funayama, Masayuki; Miura, Kazuyuki; Ogasawara, Kuniaki; Suzuki, Michiyasu; Kuroda, Kiyoshi; Sasaki, Toshiaki [Iwate Medical Univ., Morioka (Japan). School of Medicine

1998-11-01

We investigated cerebral blood flow (CBF) and metabolism in patients with hemodynamic ischemia by positron emission tomography (PET) and thermal diffusion flow meter. We also studied neuropsychological functions to evaluate the effects of surgical revascularization. Bypass surgery of the superficial temporal artery to the proximal middle cerebral artery was performed on 26 patients satisfying the following categories: stenosis or occlusive lesion in main cerebral arteries; no marked focus of infarction on CT or MRI. PET was performed before and 1 month after the operation, and CBF, the cerebral metabolic rate of oxygen (CMRO{sub 2}) and oxygen extraction fraction (OEF) were analyzed. Cerebrovascular reserve capacity (CVRC) was also calculated after acetazolamide challenge. CBF during the operation was continuously measured with a thermal diffusion flow meter. CO{sub 2} response of CBF was analyzed before and after anastomosis. Neuropsychological functions were evaluated by Hasegawa dementia scale revised (HDS-R), mini-mental state examination (MMSE) and Wechsler adult intelligence scale revised (WAIS-R). Before the operation, increase in OEF accorded with the decrease in CBF, and a significant relationship between both CBF and CVRC, and OEF and CVRC was found. A decrease in CVRC was noted prior to a decrease in CBF and elevation of OEF. CVRC caused by acetazolamide might reflect CO{sub 2} reactivity. Significant improvement of CBF and CVRC, and normalization of OEF were observed after the operation. Also, significant improvement of neuropsychological function was observed by HDS-R and WAIS-R. Disturbance in neuropsychological function might reflect elevation of OEF. (author)

Effect of STA-proximal MCA bypass. Improvement of cerebral blood flow and metabolism and neuropsychological function

International Nuclear Information System (INIS)

Ogawa, Akira; Funayama, Masayuki; Miura, Kazuyuki; Ogasawara, Kuniaki; Suzuki, Michiyasu; Kuroda, Kiyoshi; Sasaki, Toshiaki

1998-01-01

We investigated cerebral blood flow (CBF) and metabolism in patients with hemodynamic ischemia by positron emission tomography (PET) and thermal diffusion flow meter. We also studied neuropsychological functions to evaluate the effects of surgical revascularization. Bypass surgery of the superficial temporal artery to the proximal middle cerebral artery was performed on 26 patients satisfying the following categories: stenosis or occlusive lesion in main cerebral arteries; no marked focus of infarction on CT or MRI. PET was performed before and 1 month after the operation, and CBF, the cerebral metabolic rate of oxygen (CMRO 2 ) and oxygen extraction fraction (OEF) were analyzed. Cerebrovascular reserve capacity (CVRC) was also calculated after acetazolamide challenge. CBF during the operation was continuously measured with a thermal diffusion flow meter. CO 2 response of CBF was analyzed before and after anastomosis. Neuropsychological functions were evaluated by Hasegawa dementia scale revised (HDS-R), mini-mental state examination (MMSE) and Wechsler adult intelligence scale revised (WAIS-R). Before the operation, increase in OEF accorded with the decrease in CBF, and a significant relationship between both CBF and CVRC, and OEF and CVRC was found. A decrease in CVRC was noted prior to a decrease in CBF and elevation of OEF. CVRC caused by acetazolamide might reflect CO 2 reactivity. Significant improvement of CBF and CVRC, and normalization of OEF were observed after the operation. Also, significant improvement of neuropsychological function was observed by HDS-R and WAIS-R. Disturbance in neuropsychological function might reflect elevation of OEF. (author)

Peak expiratory flow as a predictor for the effectiveness of sport for patients with COPD.

Science.gov (United States)

Jungblut, S; Frickmann, H; Klingler, J; Zimmermann, B; Bargon, Joachim

2006-01-31

This study intended to find simple parameters that were able to determine the increase in physical performance as a result of sport in a group of patients with COPD (lung sport). We regularly investigated pulse, oxygenation and peak expiratory flow in participants with COPD of a "lung sport group", who participated in a structured weekly training program under professional supervision. Ten volunteers (7 females, 3 males, median of age = 69) with COPD (grade II-III) took part in the study. - The relative changes after 3 and 6 months were compared with the values of the first month of exercise. Measurements were carried out before exercise, after stamina training and at the end of the program. - Pulse and oxygenation did not show any changes. However, there was a significant improvement of peak flow after 6 months. - These peak flow changes represent further evidence of positive effects of sport in COPD and provide a parameter which allows the patients themselves to measure and evaluate the success of their physical activity.

Collateral Flow and White Matter Disease in Patients with Internal Carotid Artery Occlusion.

Science.gov (United States)

Ishikawa, Mami; Sugawara, Hitoshi; Nagai, Mutsumi; Kusaka, Gen; Tanaka, Yuichi; Naritaka, Heiji

2017-01-01

When an internal carotid artery (ICA) occludes, a patient may develop cerebral infarction (CI). We investigated whether CI caused by ICA occlusion (ICAO) is associated with collateral flow through the anterior and posterior communicating arteries (ACoA and PCoA). In 100 patients with ICAO, we investigated CI and white matter disease by performing an MRI and the anatomy of the ACoA and PCoA were investigated by performing magnetic resonance angiography. All patients were divided into the symptomatic CI group or the no-CI group. The collateral flow pathway was estimated by the anterior cerebral artery (ACA)-PCoA score and the collateral flow volume after ICAO was estimated by the middle cerebral artery (MCA) flow score, based on how well the MCA was visualized. Of 100 patients with ICAO, the symptomatic CI group included 36 patients. ACA-PCoA score and white matter disease grades were significantly higher in the CI group (indicating poor collateral flow). More than 80% of patients with an ACA-PCoA score of 4 (poor collateral) experienced symptomatic CI. Thirty-one symptomatic CI patients (86%) had an MCA flow score of 1 or 2 (decreased MCA flow). The ACA-PCoA score and white matter disease grade may suggest an increased risk of CI following ICAO. © 2016 S. Karger AG, Basel.

Lower urinary tract symptoms and urinary flow rates in female patients with hyperthyroidism.

Science.gov (United States)

Ho, Chen-Hsun; Chang, Tien-Chun; Guo, Ya-Jun; Chen, Shyh-Chyan; Yu, Hong-Jeng; Huang, Kuo-How

2011-01-01

To investigate lower urinary tract symptoms (LUTS) and voiding function in a cohort of hyperthyroid women. The autonomic nervous system (ANS) imbalance has been thought to cause LUTS in hyperthyroidism. Between January 2008 and December 2008, 65 newly diagnosed, untreated female hyperthyroid patients were enrolled in this study. Another 62 age-matched healthy women were enrolled as a control group. Demographics, LUTS, urinary flow rates, hyperthyroid symptoms, and serum levels of thyroid hormones were recorded before and after the medical treatment for hyperthyroidism. Compared with the control group, the hyperthyroid patients had a higher mean symptom score of frequency (1.15 ± 1.75 vs 0.31 ± 1.05, P = .01), incomplete emptying (0.91 ± 1.47 vs 0.29 ± 1.12, P = .02), straining (1.05 ± 0.85 vs 0.27 ± 0.51, P Hyperthyroid women demonstrated a lower mean peak flow rate (25.0 ± 5.3 vs 28.6 ± 6.1 mL/s, P = .02). After treatment, both LUTS and flow rates improved significantly. The severity of LUTS was associated with neither serum levels of thyroid hormone nor other hyperthyroid symptoms. Hyperthyroid women have worse LUTS and lower peak flow rates than healthy controls. However, the severity of LUTS is only mild (IPSS hyperthyroidism. The exact mechanisms of LUTS and/or lower urinary tract dysfunction in hyperthyroidism require further investigation. Copyright © 2011 Elsevier Inc. All rights reserved.

Fractional flow reserve versus angiography for guidance of PCI in patients with multivessel coronary artery disease (FAME)

DEFF Research Database (Denmark)

van Nunen, Lokien X; Zimmermann, Frederik M; Tonino, Pim A L

2015-01-01

BACKGROUND: In the Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) improved outcome compared with angiography-guided PCI for up to 2 years of follow-up. The aim in this study...... was to investigate whether the favourable clinical outcome with the FFR-guided PCI in the FAME study persisted over a 5-year follow-up. METHODS: The FAME study was a multicentre trial done in Belgium, Denmark, Germany, the Netherlands, Sweden, the UK, and the USA. Patients (aged ≥ 18 years) with multivessel coronary...... artery disease were randomly assigned to undergo angiography-guided PCI or FFR-guided PCI. Before randomisation, stenoses requiring PCI were identified on the angiogram. Patients allocated to angiography-guided PCI had revascularisation of all identified stenoses. Patients allocated to FFR-guided PCI had...

Hemodynamic, biological, and right ventricular functional changes following intraatrial shunt repair in patients with flow-induced pulmonary hypertension.

Science.gov (United States)

Hsu, Chih-Hsin; Roan, Jun-Neng; Wang, Jieh-Neng; Huang, Chien-Chi; Shih, Chao-Jung; Chen, Jyh-Hong; Wu, Jing-Ming; Lam, Chen-Fuh

2017-07-01

Atrial septal defects may result in pulmonary hypertension and right heart remodeling. We analyzed improvements in patients with flow-induced pulmonary hypertension and the activation of endothelial progenitor cells after flow reduction. This prospective cohort study included 37 patients who were admitted for an occluder implantation. Blood samples were collected before and after the procedure. We determined the number of endothelial progenitor cells in outgrowth colonies and serum Hsp27 concentrations. Daily performance and cardiothoracic ratio were reevaluated later. Closure of the defect significantly reduced the pulmonary pressure and B-type natriuretic peptide levels. The cardiothoracic ratio and daily performance status also improved. The number of endothelial progenitor cell outgrowth colony-forming units significantly increased and was positively correlated with daily performance. In patients with enhanced colony formation, Hsp27 levels were significantly increased. The implantation of an occluder successfully improved hemodynamic, right ventricular, and daily performance. Qualitative enhancement of colony formation for endothelial progenitor cells was also noted and positively correlated with daily performance. Closure of defects may serve as a valid, reliable model to obtain a deeper understanding of the modulation of endothelial progenitor cell activity and its relationship with pulmonary hypertension prognosis. © 2017 Wiley Periodicals, Inc.

Improvement of Measurement Accuracy of Coolant Flow in a Test Loop

Energy Technology Data Exchange (ETDEWEB)

Hong, Jintae; Kim, Jong-Bum; Joung, Chang-Young; Ahn, Sung-Ho; Heo, Sung-Ho; Jang, Seoyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In this study, to improve the measurement accuracy of coolant flow in a coolant flow simulator, elimination of external noise are enhanced by adding ground pattern in the control panel and earth around signal cables. In addition, a heating unit is added to strengthen the fluctuation signal by heating the coolant because the source of signals are heat energy. Experimental results using the improved system shows good agreement with the reference flow rate. The measurement error is reduced dramatically compared with the previous measurement accuracy and it will help to analyze the performance of nuclear fuels. For further works, out of pile test will be carried out by fabricating a test rig mockup and inspect the feasibility of the developed system. To verify the performance of a newly developed nuclear fuel, irradiation test needs to be carried out in the research reactor and measure the irradiation behavior such as fuel temperature, fission gas release, neutron dose, coolant temperature, and coolant flow rate. In particular, the heat generation rate of nuclear fuels can be measured indirectly by measuring temperature variation of coolant which passes by the fuel rod and its flow rate. However, it is very difficult to measure the flow rate of coolant at the fuel rod owing to the narrow gap between components of the test rig. In nuclear fields, noise analysis using thermocouples in the test rig has been applied to measure the flow velocity of coolant which circulates through the test loop.

Relationship between spontaneous expiratory flow-volume curve pattern and air-flow obstruction in elderly COPD patients.

Science.gov (United States)

Nozoe, Masafumi; Mase, Kyoshi; Murakami, Shigefumi; Okada, Makoto; Ogino, Tomoyuki; Matsushita, Kazuhiro; Takashima, Sachie; Yamamoto, Noriyasu; Fukuda, Yoshihiro; Domen, Kazuhisa

2013-10-01

Assessment of the degree of air-flow obstruction is important for determining the treatment strategy in COPD patients. However, in some elderly COPD patients, measuring FVC is impossible because of cognitive dysfunction or severe dyspnea. In such patients a simple test of airways obstruction requiring only a short run of tidal breathing would be useful. We studied whether the spontaneous expiratory flow-volume (SEFV) curve pattern reflects the degree of air-flow obstruction in elderly COPD patients. In 34 elderly subjects (mean ± SD age 80 ± 7 y) with stable COPD (percent-of-predicted FEV(1) 39.0 ± 18.5%), and 12 age-matched healthy subjects, we measured FVC and recorded flow-volume curves during quiet breathing. We studied the SEFV curve patterns (concavity/convexity), spirometry results, breathing patterns, and demographics. The SEFV curve concavity/convexity prediction accuracy was examined by calculating the receiver operating characteristic curves, cutoff values, area under the curve, sensitivity, and specificity. Fourteen subjects with COPD had a concave SEFV curve. All the healthy subjects had convex SEFV curves. The COPD subjects who had concave SEFV curves often had very severe airway obstruction. The percent-of-predicted FEV(1)% (32.4%) was the most powerful SEFV curve concavity predictor (area under the curve 0.92, 95% CI 0.83-1.00), and had the highest sensitivity (0.93) and specificity (0.88). Concavity of the SEFV curve obtained during tidal breathing may be a useful test for determining the presence of very severe obstruction in elderly patients unable to perform a satisfactory FVC maneuver.

Recent improvements of the French liquid micro-flow reference facility

Science.gov (United States)

Florestan, Ogheard; Sandy, Margot; Julien, Savary

2018-02-01

According to the mission of the national reference laboratory, LNE-CETIAT achieved in 2012 the construction and accreditation of a modern and innovative calibration laboratory based on the gravimetric method. The measurement capabilities cover a flow rate range for liquid from 10 kg · h-1 down to 1 g · h-1 with expanded relative uncertainties from 0.1% to 0.6% (k  =  2). Since 2012, several theoretical and experimental studies have allowed a better knowledge and control over uncertainty sources and have decreased calibration time. When dealing with liquid micro-flow using a reference method such as the gravimetric method, several difficulties have to be overcome. The main improvements described in this paper relate to the enhancement of the evaporation trap system, the merging of the four dedicated measurement lines into one, and the implementation of a gravimetric dynamic ‘flying’ method for the calculation of the reference flow rate. The evaporation-avoiding system has been replaced by an oil layer in order to remove the possibility of condensation of water on both the weighed vessel and the immersed capillary. The article describes the experimental method used to quantify the effect of surface tension of water/oil/air interfaces on the weighed mass. The traditional static gravimetric method has been upgraded by a dynamic ‘flying’ gravimetric method. The article presents the newly implemented method, its validation and its advantages compared to the static method. The four dedicated weighing devices, dispatched over four sub-ranges of flow rate, have been merged leading to the use of only one weighing scale with the same uncertainties on the reference flow rate. The article discusses the new uncertainty budget over the full flow rate range capability. Finally, the article discusses the improvements still under development and the general prospects of liquid micro-flow metrology.

Domiciliary humidification improves lung mucociliary clearance in patients with bronchiectasis.

Science.gov (United States)

Hasani, A; Chapman, T H; McCool, D; Smith, R E; Dilworth, J P; Agnew, J E

2008-01-01

Inspired air humidification has been reported to show some benefit in bronchiectatic patients. We have investigated the possibility that one effect might be to enhance mucociliary clearance. Such enhancement might, if it occurs, help to lessen the risks of recurrent infective episodes. Using a radioaerosol technique, we measured lung mucociliary clearance before and after 7 days of domiciliary humidification. Patients inhaled high flow saturated air at 37 degrees C via a patient-operated humidification nasal inhalation system for 3 h per day. We assessed tracheobronchial mucociliary clearance from the retention of (99m)Tc-labelled polystyrene tracer particles monitored for 6 h, with a follow-up 24-h reading. Ten out of 14 initially recruited patients (age 37-75 years; seven females) completed the study (two withdrew after their initial screening and two prior to the initial clearance test). Seven patients studied were non-smokers; three were ex-smokers (1-9 pack-years). Initial tracer radioaerosol distribution was closely similar between pre- and post-treatment. Following humidification, lung mucociliary clearance significantly improved, the area under the tracheobronchial retention curve decreased from 319 +/- 50 to 271 +/- 46%h (p humidification treatment improved lung mucociliary clearance in our bronchiectatic patients. Given this finding plus increasing laboratory and clinical interest in humidification mechanisms and effects, we believe further clinical trials of humidification therapy are desirable, coupled with analysis of humidification effects on mucus properties and transport.

MR evaluation of cervical CSF flow. An examination in patients with spinal canal stenosis

Energy Technology Data Exchange (ETDEWEB)

Iida, Makoto [Miyoshi General Hospital, Hiroshima (Japan); Kajima, Toshio; Miyasaka, Kenji; Nakanishi, Tadashi; Ono, Chiaki; Ito, Katsuhide

1999-06-01

To evaluate the flow dynamics of cerebrospinal fluid (CSF) throughout the cervical spine, 18 healthy controls and 14 patients with spinal canal stenosis were examined by phase-contrast cine MR. MR imaging was performed using a sagittal technique that is flow-sensitive in the craniocaudal direction. Flow encoding depicted craniocaudal flow as high intensity and caudocranial flow as low intensity. In this technique, either retrospective cardiac or peripheral gating was used to cover the complete cardiac cycle. This pulse sequence yielded 16 quantitative flow-encoded images per cardiac cycle. Using a region-of-interest cursor at each vertebral level, the graphs of flow-velocity versus time were generated. The recorded CSF at each vertebral level in the controls showed almost the same pattern in the change of flow in the craniocaudal direction, indicating that the onset of craniocaudal CSF flow was synchronous with the onset of cardiac systole in these subjects. At all vertebral levels, flow-velocity time curves showed the same variation in pattern. CSF flow was significantly lower in patients than in controls at each vertebral level (p<0.01). In addition, the flow patterns of the patients with spinal canal stenosis differed at each vertebral level. As a results, the total sum of the difference in velocity between graphs of two serial vertebrae at all sampling points (the area between the curves: ABC) per mean velocity amplitude in the patients was significantly higher than controls (p<0.05). Furthermore, the ABC per mean velocity amplitude at the stenotic level was significantly larger in the patients than that at the non-stenotic level (p<0.01). These data suggest that turbulent CSF flow occurs at the stenotic level. Thus, assessment of CSF flow dynamics is a useful adjunct to routine MRI in patients with spinal canal stenosis. (author)

Train flow chaos analysis based on an improved cellular automata model

International Nuclear Information System (INIS)

Meng, Xuelei; Xiang, Wanli; Jia, Limin; Xu, Jie

2015-01-01

To control the chaos in the railway traffic flow and offer valuable information for the dispatchers of the railway system, an improved cellular model is presented to detect and analyze the chaos in the traffic flow. We first introduce the working mechanism of moving block system, analyzing the train flow movement characteristics. Then we improve the cellular model on the evolution rules to adjust the train flow movement. We give the train operation steps from three cases: the trains running on a railway section, a train will arrive in a station and a train will departure from a station. We simulate 4 trains to run on a high speed section fixed with moving block system and record the distances between the neighbor trains and draw the Poincare section to analyze the chaos in the train operation. It is concluded that there is not only chaos but order in the train operation system with moving blocking system and they can interconvert to each other. The findings have the potential value in train dispatching system construction and offer supporting information for the daily dispatching work.

Using Six Sigma and Lean methodologies to improve OR throughput.

Science.gov (United States)

Fairbanks, Catharine B

2007-07-01

Improving patient flow in the perioperative environment is challenging, but it has positive implications for both staff members and for the facility. One facility in vermont improved patient throughput by incorporating Six Sigma and Lean methodologies for patients undergoing elective procedures. The results of the project were significantly improved patient flow and increased teamwork and pride among perioperative staff members. (c) AORN, Inc, 2007.

Coronary grafts flow and cardiac pacing modalities: how to improve perioperative myocardial perfusion.

LENUS (Irish Health Repository)

D'Ancona, Giuseppe

2012-02-03

OBJECTIVE: Aim of this study was to investigate modifications of coronary grafts flow during different pacing modalities after CABG. MATERIALS AND METHODS: Two separate prospective studies were conducted in patients undergoing CABG and requiring intraoperative epicardial pacing. In a first study (22 patients) coronary grafts flows were measured during dual chamber pacing (DDD) and during ventricular pacing (VVI). In a second study (10 patients) flows were measured during DDD pacing at different atrio-ventricular (A-V) delay periods. A-V delay was adjusted in 25 ms increments from 25 to 250 ms and flow measurements were performed for each A-V delay increment. A transit time flowmeter was used for the measurements. RESULTS: An average of 3.4 grafts\\/patient were performed. In the first study, average coronary graft flow was 47.4+\\/-20.8 ml\\/min during DDD pacing and 41.8+\\/-18.2 ml\\/min during VVI pacing (P = 0.0004). Furthermore average systolic pressure was 94.3+\\/-10.1 mmHg during DDD pacing and 89.6+\\/-12.2 mmHg during VVV pacing (P = 0.0007). No significant differences in diastolic pressure were recorded during the two different pacing modalities. In the second study, maximal flows were achieved during DDD pacing with an A-V delay of 175 ms (54+\\/-9.6 ml\\/min) and minimal flows were detected at 25 ms A-V delay (38.1+\\/-4.7 ml\\/min) (P=ns). No significant differences in systolic or diastolic blood pressure were noticed during the different A-V delays. CONCLUSION: Grafts flowmetry provides an extra tool to direct supportive measures such as cardiac pacing after CABG. DDD mode with A-V delay around 175 ms. should be preferred to allow for maximal myocardial perfusion via the grafts.

[Assessment of maternal cerebral blood flow in patients with preeclampsia].

Science.gov (United States)

Mandić, Vesna; Miković, Zeljko; Dukić, Milan; Vasiljević, Mladenko; Filimonović, Dejan; Bogavac, Mirjana

2005-01-01

Systemic vasoconstriction in preeclamptic patients increases vascular resistance, and is manifested by increased arterial blood flow velocity. The aim of the study is to evaluate if there is a change of Doppler indices in maternal medial cerbral artery (MCA) in severe preeclampsia due to: 1) severity of clinical symptoms, 2) the begining of eclamptic attack and 3) the application of anticonvulsive therapy. A prospective clinical study included 92 pregnant women, gestational age 28-36 weeks. They were divided into three groups: normotensive (n=30), mild preeclampsia (n=33), and severe preeclampsia (n=29). We investigated maternal cerebral circulation by assessing the MCA. We registrated: pulsatility index (Pi), resistance index (Ri), systolic/diastolic ratio (S/D), and the maximum systolic, end diastolic and medium velocity. Patients with severe preeclampsia were divided into two subgroups. subgroup 1 included patients without symptoms of threatening eclampsia (n=18; 62.06%); while subgroup 2 included those with symptoms of preeclampsia (n=11; 37.94%). All patients with severe preeclampsia were treated with magnesium sulfate (MgSO4), and cerebral blood flow was measured before and after the treatment. Statistical analysis was done by oneway ANOVA, Student t-test and t-paired sample test. The difference was considered to be significant if ppreclampsia we found increased velocity values, Pi and Ri, especially in patients with signs of threatened eclampsia, suggesting that blood vessels changes are most prominent in severe preeclampsia. Cerebral blood flow meassurements can be used as a clinical test for the prediction of eclampsia. Magnesium-sulfate (MgSO4) has a signifficant role in prophylaxis and treatment of eclampsia, and, therefore, positive influence on reduction of cerebral ishemic lesions can be expected. We can conclude that changes of the cerebral blood flow can be evaluated by evaluating blood flow velocities in the medial cerebral artery. Velocities tend

Improvements to TRAC models of condensing stratified flow. Pt. 1

International Nuclear Information System (INIS)

Zhang, Q.; Leslie, D.C.

1991-12-01

Direct contact condensation in stratified flow is an important phenomenon in LOCA analyses. In this report, the TRAC interfacial heat transfer model for stratified condensing flow has been assessed against the Bankoff experiments. A rectangular channel option has been added to the code to represent the experimental geometry. In almost all cases the TRAC heat transfer coefficient (HTC) over-predicts the condensation rates and in some cases it is so high that the predicted steam is sucked in from the normal outlet in order to conserve mass. Based on their cocurrent and countercurrent condensing flow experiments, Bankoff and his students (Lim 1981, Kim 1985) developed HTC models from the two cases. The replacement of the TRAC HTC with either of Bankoff's models greatly improves the predictions of condensation rates in the experiment with cocurrent condensing flow. However, the Bankoff HTC for countercurrent flow is preferable because it is based only on the local quantities rather than on the quantities averaged from the inlet. (author)

Fractional Flow Reserve-Guided Complete Revascularization Improves the Prognosis in Patients With ST-Segment-Elevation Myocardial Infarction and Severe Nonculprit Disease

DEFF Research Database (Denmark)

Lønborg, Jacob; Engstrøm, Thomas; Kelbæk, Henning

2017-01-01

, and severity of the noninfarct-related stenosis on the effect of fractional flow reserve-guided complete revascularization. METHODS AND RESULTS: In the DANAMI-3-PRIMULTI study (Primary PCI in Patients With ST-Elevation Myocardial Infarction and Multivessel Disease: Treatment of Culprit Lesion Only or Complete...

Topiramate improves neurovascular function, epidermal nerve fiber morphology, and metabolism in patients with type 2 diabetes mellitus

Directory of Open Access Journals (Sweden)

Boyd A

2010-12-01

Full Text Available Amanda L Boyd, Patricia M Barlow, Gary L Pittenger, Kathryn F Simmons, Aaron I VinikDepartment of Internal Medicine, Eastern Virginia Medical School, Norfolk, VA, USAPurpose: To assess the effects of topiramate on C-fiber function, nerve fiber morphology, and metabolism (including insulin sensitivity, obesity, and dyslipidemia in type 2 diabetes.Patients and methods: We conducted an 18-week, open-label trial treating patients with topiramate. Twenty subjects with type 2 diabetes and neuropathy (61.5 ± 1.29 years; 15 male, 5 female were enrolled and completed the trial. Neuropathy was evaluated by total neuropathy scores, nerve conduction studies, quantitative sensory tests, laser Doppler skin blood flow, and intraepidermal nerve fibers in skin biopsies.Results: Topiramate treatment improved symptoms compatible with C-fiber dysfunction. Weight, blood pressure, and hemoglobin A1c also improved. Laser Doppler skin blood flow improved significantly after 12 weeks of treatment, but returned to baseline at 18 weeks. After 18 weeks of treatment there was a significant increase in intraepidermal nerve fiber length at the forearm, thigh, and proximal leg. Intraepidermal nerve fiber density was significantly increased by topiramate in the proximal leg.Conclusion: This study is the first to demonstrate that it is possible to induce skin intraepidermal nerve fiber regeneration accompanied by enhancement of neurovascular function, translating into improved symptoms as well as sensory nerve function. The simultaneous improvement of selective metabolic indices may play a role in this effect, but this remains to be determined.Keywords: diabetic neuropathy, skin blood flow, skin biopsy, diabetes

Regional cerebral blood flow study with 123I-IMP in patients with degenerative dementia

International Nuclear Information System (INIS)

Ohnishi, T.; Hoshi, H.; Nagamachi, S.; Jinnouchi, S.; Futami, S.; Watanabe, K.; Mitsuyama, Y.

1991-01-01

Regional cerebral blood flow was evaluated by single-photon emission CT (SPECT) with 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) in 11 patients with dementia of the Alzheimer type, three patients with progressive dementia and motor neuron disease, and eight healthy control subjects. Regional blood flow measurements in the bilateral frontal, parietal association, and temporal cortices were lower in the Alzheimer dementia patients than in controls. Flow deficits in the parietal association cortex were demonstrated in all patients with Alzheimer-type dementia; these deficits were correlated with the severity of disease. Lateral hemispheric asymmetry was seen in nine of 11 patients with Alzheimer-type dementia. In all three patients with progressive dementia and motor neuron disease, flow deficits were demonstrated in the bilateral frontal and temporal cortices, but no flow deficits were seen in the parietal association cortex. Brain SPECT with 123I-IMP may be useful in the differential diagnosis and evaluation of the severity of degenerative dementia

Methods of measurement of myocardial blood flow in patients: a critical review

International Nuclear Information System (INIS)

Marcus, M.L.; Wilson, R.F.; White, C.W.

1987-01-01

During the past decade, major progress has been made in the evolution of technology directed toward the accurate measurement of regional myocardial perfusion in patients. The deficiencies of some of the older methods (thermodilution and gas clearance) are better appreciated and improved approaches (Doppler catheters, positron-emission tomography, and digital subtraction angiography) have been developed. The new approaches should play a major role in research and for most applications the older methods will gradually be replaced. Efforts to bring these new methods to community hospitals and practicing cardiologists should be stimulated. Doppler catheters, positron-emission tomography, and digital-subtraction angiography are commercially available and Doppler catheters and digital-subtraction angiography could be easily incorporated into routine cardiac catheterization procedures. The Doppler catheter is the most inexpensive and probably the simplest to apply. In our opinion, routine measurements of coronary flow reserve will significantly improve the care of patients with coronary obstructive disease and other diseases that impair myocardial perfusion. If coronary reserve measurements are used frequently, patient selection for coronary angioplasty and bypass surgery will no longer depend entirely on visual assessment of percent diameter stenosis, a very poor criterion in many situations. Also, patients with chest pain syndromes, normal coronary vessels, and impaired coronary reserve will be identified and perhaps some effective treatment for this condition will be devised. 77 references

Information flow to assess cardiorespiratory interactions in patients on weaning trials.

Science.gov (United States)

Vallverdú, M; Tibaduisa, O; Clariá, F; Hoyer, D; Giraldo, B; Benito, S; Caminal, P

2006-01-01

Nonlinear processes of the autonomic nervous system (ANS) can produce breath-to-breath variability in the pattern of breathing. In order to provide assess to these nonlinear processes, nonlinear statistical dependencies between heart rate variability and respiratory pattern variability are analyzed. In this way, auto-mutual information and cross-mutual information concepts are applied. This information flow analysis is presented as a short-term non linear analysis method to investigate the information flow interactions in patients on weaning trials. 78 patients from mechanical ventilation were studied: Group A of 28 patients that failed to maintain spontaneous breathing and were reconnected; Group B of 50 patients with successful trials. The results show lower complexity with an increase of information flow in group A than in group B. Furthermore, a more (weakly) coupled nonlinear oscillator behavior is observed in the series of group A than in B.

Uranium Dioxide Powder Flow ability Improvement Using Sol-Gel

International Nuclear Information System (INIS)

Juanda, D.; Sambodo Daru, G.

1998-01-01

The improvement of flow ability characteristics of uranium dioxide powder has been done using sol-gel process. To anticipate a pellet mass production with uniform pellet dimension, the uranium dioxide powder must be have a spherical form. Uranium dioxide spherical powder has been diluted in acid transformed into sol colloidal solution. To obtain uranium dioxide spherical form, the uranium sol-colloidal solution has been dropped in a hot paraffin ( at the temperature of 90 0 C) to form gelatinous colloid and then dried at 800 0 C, and sintered at the temperature of 1700 0 C. The flow ability of spherical uranium dioxide powder has been examined by using Flowmeter Hall (ASTM. B. 213-46T). The measurement result reveals that the spherical uranium dioxide powder has a flow ability twice than that of unprocessed uranium dioxide powder

The clinical study of cerebral blood flow imaging in patients with early syphilis

International Nuclear Information System (INIS)

Liu Zengli; Shi Xin; Wu Jinchang; Tang Jun; Zhong Jijun

2003-01-01

Objective: To study the clinical value of cerebral blood flow imaging for evaluation of patients with early syphilis. Methods: Fifty-three patients with early syphilis underwent cerebral blood flow imaging using 99 Tc m -ethylenecysteinate dimer(ECD). Regional cerebral blood flow (rCBF) changes were analyzed. Results: The acquired images of 53 patients were graded as 5 types. The rCBF was significantly depressed in 48 of 53 patients mainly in the areas dominated by anterior cerebral artery and middle cerebral artery. Conclusion: Treponema pallidum (TP) could start invading central nervous system at the early stage of infection

Ultrasonic particle image velocimetry for improved flow gradient imaging: algorithms, methodology and validation

International Nuclear Information System (INIS)

Niu Lili; Qian Ming; Yu Wentao; Jin Qiaofeng; Ling Tao; Zheng Hairong; Wan Kun; Gao Shen

2010-01-01

This paper presents a new algorithm for ultrasonic particle image velocimetry (Echo PIV) for improving the flow velocity measurement accuracy and efficiency in regions with high velocity gradients. The conventional Echo PIV algorithm has been modified by incorporating a multiple iterative algorithm, sub-pixel method, filter and interpolation method, and spurious vector elimination algorithm. The new algorithms' performance is assessed by analyzing simulated images with known displacements, and ultrasonic B-mode images of in vitro laminar pipe flow, rotational flow and in vivo rat carotid arterial flow. Results of the simulated images show that the new algorithm produces much smaller bias from the known displacements. For laminar flow, the new algorithm results in 1.1% deviation from the analytically derived value, and 8.8% for the conventional algorithm. The vector quality evaluation for the rotational flow imaging shows that the new algorithm produces better velocity vectors. For in vivo rat carotid arterial flow imaging, the results from the new algorithm deviate 6.6% from the Doppler-measured peak velocities averagely compared to 15% of that from the conventional algorithm. The new Echo PIV algorithm is able to effectively improve the measurement accuracy in imaging flow fields with high velocity gradients.

Coronary flow response to remote ischemic preconditioning is preserved in old cardiac patients.

Science.gov (United States)

Santillo, Elpidio; Migale, Monica; Balestrini, Fabrizio; Postacchini, Demetrio; Bustacchini, Silvia; Lattanzio, Fabrizia; Antonelli-Incalzi, Raffaele

2017-10-20

The effect of remote ischemic preconditioning (RIPC) on coronary flow in elderly cardiac patients has not been investigated yet. Thus, we aimed to study the change of coronary flow subsequent to RIPC in old patients with heart diseases and to identify its main correlates. Ninety-five elderly patients (aged ≥ 65 years) accessing cardiac rehabilitation ward underwent transthoracic ultrasound evaluation of peak diastolic flow velocity of left anterior descending artery. Measurements of coronary flow velocity were performed on baseline and after an RIPC protocol (three cycles of 5 min ischemia of right arm alternating 5 min reperfusion). Differences between subjects with coronary flow velocity change over or equal the 75° percentile (high-responders) and subjects with a coronary flow velocity change under the 75° percentile (low-responders) were assessed. In enrolled elderly heart patients, coronary flow velocity significantly augmented from baseline after RIPC [0.23 m/s (0.18-0.28) vs 0.27 m/s (0.22-0.36); p < 0.001 by Wilcoxon test]. High-responders to RIPC were significantly younger and in better functional status than low-responders. Heart failure resulted as the main variable associated with impairment of RIPC responsiveness (R 2  = 0.202; p = 0.002)]. Our sample of old cardiac patients presented a significant median increment of coronary flow velocity after RIPC. The magnitude of the observed change of coronary flow velocity was comparable to that previously described in healthy subjects. The coronary response to RIPC was attenuated by heart failure. Further research should define whether such RIPC responsiveness is associated with cardioprotection and carries prognostic implications.

Evaluation of Marfan patients status post valve-sparing aortic root replacement with 4D flow.

Science.gov (United States)

Hope, Thomas A; Kvitting, John-Peder Escobar; Hope, Michael D; Miller, D Craig; Markl, Michael; Herfkens, Robert J

2013-11-01

Over the past two decades elective valve-sparing aortic root replacement (V-SARR) has become more common in the treatment of patients with aortic root and ascending aortic aneurysms. Currently there are little data available to predict complications in the post-operative population. The study goal was to determine if altered flow patterns in the thoracic aorta, as measured by MRI, are associated with complications after V-SARR. Time-resolved three-dimensional phase-contrast MRI (4D flow) was used to image 12 patients with Marfan syndrome after V-SARR. The patients were followed up for an average of 5.8 years after imaging and 8.2 years after surgery. Additionally 5 volunteers were imaged for comparison. Flow profiles were visualized during peak systole using streamlines. Wall shear stress estimates and normalized flow displacement were evaluated at multiple planes in the thoracic aorta. During the follow-up period, a single patient developed a Stanford Type B aortic dissection. At initial imaging, prior to the development of the dissection, the patient had altered flow patterns, wall shear stress estimates, and increased normalized flow displacement in the thoracic aorta in comparison to the remaining V-SARR patients and volunteers. This is the first follow-up study of patients after 4D flow imaging. An aortic dissection developed in one patient with altered flow patterns and hemodynamic stresses in the thoracic aorta. These results suggest that flow and altered hemodynamics may play a role in the development of post-operative intramural hematomas and dissections. Copyright © 2013 Elsevier Inc. All rights reserved.

The use of high-flow nasal oxygen in COPD patients

Directory of Open Access Journals (Sweden)

Silva Santos P

2016-09-01

Full Text Available Pedro Silva Santos,1 Antonio M Esquinas21Pulmonology Unit, Centro Hospitalar e Universitário de Coimbra – Hospitais da Universidade de Coimbra, Coimbra, Portugal; 2Internsive Care Unit, Hospital Morales Meseguer, Múrcia, SpainHigh-flow nasal cannula (HFNC oxygen therapy is an innovative and useful mode for the treatment of patients with respiratory failure.1–3 It delivers heated and humidified air providing higher and more expected gas flow rates and fraction inspired oxygen (FiO2 than traditional oxygen therapy.2     We read the article by Bräunlich et al1 carefully and congratulate the authors on their study about the use of nasal high-flow therapy in COPD patients. There are, however, some limitations to the study that need to be considered.    First, this study has a small number of patients, particularly in groups A and B, which in our opinion will affect the comparison of data with the group C that contains a greater variety of patients with more severe outcomes, including forced expiratory volume in 1 second and forced vital capacity. Second, as a study on mean airway pressure, it would be interesting to evaluate partial pressure of CO2 with higher flows.    Third, one of the aims of this study was to characterize changes in hypercapnia, so it is not correct to include nonhypercapnic patients. Fourth, it would be interesting to know the FiO2 that was given and whether the patients had domiciliary oxygen or noninvasive ventilation, as most of them are hypercapnic patients. Finally, regarding comfort and dyspnea scale, HFNC showed better results, which may increase its use when intolerant to noninvasive ventilation.    In short, HFNC is an interesting mode for the future treatment of COPD patients with respiratory failure, which may lead to larger and randomized trials to confirm this indication.View original paper by Bräunlich et al.

Assessment of intracardiac flow and vorticity in the right heart of patients after repair of tetralogy of Fallot by flow-sensitive 4D MRI

Energy Technology Data Exchange (ETDEWEB)

Hirtler, Daniel [University Hospital Freiburg, Department of Congenital Heart Defects and Pediatric Cardiology (Heart Center, University of Freiburg), Freiburg (Germany); Garcia, Julio; Barker, Alex J. [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Geiger, Julia [University Childrens' Hospital Zurich, Department of Radiology, Zurich (Switzerland)

2016-10-15

To comprehensively and quantitatively analyse flow and vorticity in the right heart of patients after repair of tetralogy of Fallot (rTOF) compared with healthy volunteers. Time-resolved flow-sensitive 4D MRI was acquired in 24 rTOF patients and 12 volunteers. Qualitative flow evaluation was based on consensus reading of two observers. Quantitative analysis included segmentation of the right atrium (RA) and ventricle (RV) in a four-chamber view to extract volumes and regional haemodynamic information for computation of regional mean and peak vorticity. Right heart intra-atrial, intraventricular and outflow tract flow patterns differed considerably between rTOF patients and volunteers. Peak RA and mean RV vorticity was significantly higher in patients (p = 0.02/0.05). Significant negative correlations were found between patients' maximum and mean RV and RA vorticity and ventricular volumes (p < 0.05). The main pulmonary artery (MPA) regurgitant flow was associated with higher RA and RV vorticity, which was significant for RA maximum and RV mean vorticity (p = 0.01/0.03). The calculation of vorticity based on 4D flow data is an alternative approach to assess intracardiac flow changes in rTOF patients compared with qualitative flow visualization. Alterations in intracardiac vorticity could be relevant with regard to the development of RV dilation and impaired function. (orig.)

Assessment of intracardiac flow and vorticity in the right heart of patients after repair of tetralogy of Fallot by flow-sensitive 4D MRI

International Nuclear Information System (INIS)

Hirtler, Daniel; Garcia, Julio; Barker, Alex J.; Geiger, Julia

2016-01-01

To comprehensively and quantitatively analyse flow and vorticity in the right heart of patients after repair of tetralogy of Fallot (rTOF) compared with healthy volunteers. Time-resolved flow-sensitive 4D MRI was acquired in 24 rTOF patients and 12 volunteers. Qualitative flow evaluation was based on consensus reading of two observers. Quantitative analysis included segmentation of the right atrium (RA) and ventricle (RV) in a four-chamber view to extract volumes and regional haemodynamic information for computation of regional mean and peak vorticity. Right heart intra-atrial, intraventricular and outflow tract flow patterns differed considerably between rTOF patients and volunteers. Peak RA and mean RV vorticity was significantly higher in patients (p = 0.02/0.05). Significant negative correlations were found between patients' maximum and mean RV and RA vorticity and ventricular volumes (p < 0.05). The main pulmonary artery (MPA) regurgitant flow was associated with higher RA and RV vorticity, which was significant for RA maximum and RV mean vorticity (p = 0.01/0.03). The calculation of vorticity based on 4D flow data is an alternative approach to assess intracardiac flow changes in rTOF patients compared with qualitative flow visualization. Alterations in intracardiac vorticity could be relevant with regard to the development of RV dilation and impaired function. (orig.)

Improvement of quantum efficiency in green light-emitting diodes with pre-TMIn flow treatment

International Nuclear Information System (INIS)

Lee, Ya-Ju; Chen, Yi-Ching; Lu, Tien-Chang

2011-01-01

The effects of pre-trimethlyindium (TMIn) flow on the improved electrical characteristics and highly stable temperature properties of InGaN green light-emitting diodes (LEDs) are discussed. For the LED sample with a pre-TMIn flow treatment, the tunnelling of injected carriers associated with threading defects is significantly reduced, which promotes the diffusion-recombination of injected carriers, as well as the overall emission efficiency of the LED. In addition, the pre-TMIn flow treatment evidently reduces the dependence of external quantum efficiency on temperature and efficiency droop of green LEDs. As a result, we conclude that the pre-TMIn flow treatment is a promising scheme for the improvement of output performance of InGaN-based green LEDs.

Heliox delivered by high flow nasal cannula improves oxygenation in infants with respiratory syncytial virus acute bronchiolitis

Directory of Open Access Journals (Sweden)

Wael Seliem

Full Text Available Abstract Objective: The objective of this study is to evaluate the hypothesis that use of heliox would result in improvement of gas exchange when used with high flow nasal cannula in infants with RSV acute bronchiolitis. Methods: All patients that met the inclusion criteria were randomized to either heliox (70:30 or air-oxygen mixture 30% via high flow nasal cannula at 8 L/min for a continuous 24 h. Measurements were taken at baseline, after 2 h, and at the end of the 24 h. Results: This prospective study included 48 patients. After 2 h of treatment with heliox, the oxygen saturation and PaO2 significantly improved when compared with the air-oxygen group, 98.3% vs. 92.9%, 62.0 mmHg vs. 43.6 mmHg (p = 0.04 and 0.01, respectively. Furthermore, PaO2/FiO2 ratio was significantly higher in the heliox group when compared with the air-oxygen group, 206.7 vs. 145.3. Nevertheless, CO2 showed better elimination when heliox was used, without significance. MWCA score dropped significantly in the heliox group, 2.2 points vs. 4.0 points in air-oxygen (p = 0.04, 2 h after starting the therapy. Conclusion: Transient improvement of oxygenation in infants with RSV acute bronchiolitis during the initial phase of the therapy is associated with heliox when provided with HFNC, may provide a precious time for other therapeutic agents to work or for the disease to resolve naturally, avoiding other aggressive interventions.

Nocturnal foot blood flow in patients with arterial insufficiency

DEFF Research Database (Denmark)

Jelnes, Rolf; Tønnesen, K H

1984-01-01

Twenty-four hour continuous recording of xenon (133Xe) wash-out from the forefoot was performed on patients with normal circulations (n = 10) and on patients with different degrees of arterial insufficiency (n = 36). During day hours the calculated subcutaneous blood flow in the forefoot was on a...

Improved simulation of peak flows under climate change: post-processing or composite opjective calibration?

NARCIS (Netherlands)

Zhang, Xujie; Booij, Martijn J.; Xu, YuePing

2015-01-01

Climate change is expected to have large impacts on peak flows. However, there may be bias in the simulation of peak flows by hydrological models. This study aims to improve the simulation of peak flows under climate change in Lanjiang catchment, east China, by comparing two approaches:

Improved oxygen-activation method for determining water flow behind casing

International Nuclear Information System (INIS)

McKeon, D.C.; Scott, H.D.; Olesen, J.R.; Patton, G.L.; Mitchell, R.J.

1991-01-01

This paper reports on impulse activation which is a new oxygen-activation technique developed to detect vertical water flow and to provide a quantitative measure of water flow velocity and flow rate. Flow-loop measurements made over a wide range of water velocities are in good agreement with theoretical predictions. Measurements of up- and downward channel flow were made at the U.S. Environmental Protection Agency (EPA) leak test well in Ada, OK, to demonstrate the technique in a controlled environment and to confirm that EPA requirements have been met. A major advantage of this method over previous procedures is that a measurement is a known zero-flow zone is not required. The impulse-activation technique has improved sensitivity to both low and high flow rates. In the EPA leak test well, the technique successfully discriminated between 0- and 1.4 ft/min flow conditions. The lowest quantified velocity was 1.8 ft/min or 10 BWPD, significantly below the EPA requirement of 3 ft/min. The upper limit of detection has not been determined by exceeds 137 ft/min. The water flow log (WFL SM ) measurement uses the impulse-activation technique and a Dual-Bust SM , thermal-decay-time (TDT SM ) tool to detect water flow behind casing. An important application of this measurement is testing for fluid migration in the wellbore as part of the mechanical integrity testing process for Class I and II disposal wells. The new oxygen-activation measurement was used in numerous production wells to identify the presence of water flow behind casing. Additional applications include the identification of open fractures in horizontal wells and the quantification of water flow in the tubing/casing annulus in injection and production wells

Differential visceral blood flow in the hyperdynamic circulation of patients with liver cirrhosis.

Science.gov (United States)

McAvoy, N C; Semple, S; Richards, J M J; Robson, A J; Patel, D; Jardine, A G M; Leyland, K; Cooper, A S; Newby, D E; Hayes, P C

2016-05-01

With advancing liver disease and the development of portal hypertension, there are major alterations in somatic and visceral blood flow. Using phase-contrast magnetic resonance angiography, we characterised alterations in blood flow within the hepatic, splanchnic and extra-splanchnic circulations of patients with established liver cirrhosis. To compare blood flow in splanchnic and extra-splanchnic circulations in patients with varying degrees of cirrhosis and healthy controls. In a single-centre prospective study, 21 healthy volunteers and 19 patients with established liver disease (Child's stage B and C) underwent electrocardiogram-gated phase-contrast-enhanced 3T magnetic resonance angiography of the aorta, hepatic artery, portal vein, superior mesenteric artery, and the renal and common carotid arteries. In comparison to healthy volunteers, resting blood flow in the descending thoracic aorta was increased by 43% in patients with liver disease (4.31 ± 1.47 vs. 3.31 ± 0.80 L/min, P = 0.011). While portal vein flow was similar (0.83 ± 0.38 vs. 0.77 ± 0.35 L/min, P = 0.649), hepatic artery flow doubled (0.50 ± 0.46 vs. 0.25 ± 0.15 L/min, P = 0.021) and consequently total liver blood flow increased by 30% (1.33 ± 0.84 vs. 1.027 ± 0.5 L/min, P = 0.043). In patients with liver disease, superior mesenteric artery flow was threefold higher (0.65 ± 0.35 vs. 0.22 ± 0.13 L/min, P phenomenon. These circulatory disturbances may underlie many of the manifestations of advanced liver disease. © 2016 John Wiley & Sons Ltd.

[Value of fractional flow reserve measurement in endovascular therapy for patients with Stanford B type aortic dissection complicated with renal blood flow injury].

Science.gov (United States)

Guo, Xi; Li, Peng; Liu, Guangrui; Huang, Xiaoyong; Yong, Qiang; Wang, Guoqin; Huang, Lianjun

2015-10-01

To analyze the value of fractional flow reserve (FFR) measurement on endovascular therapy for patients with renal artery stenosis. Clinical data of 12 patients with Stanford B type aortic dissection complicated with renal blood flow injury in Anzhen hospital hospitalized from May 2013 to February 2014 were retrospectively analyzed. Renal artery angiography was performed and fractional flow reserve (FFR) was measured before Thoracic endovascular aortic repair. After operation, renal artery FFR was measured again, and renal artery stenting was performed in patients with FFR ≤ 0.90 or average pressure difference between proximal and distal of renal artery > 20 mmHg (1 mmHg = 0.133 kPa) and not applied for patients with FFR > 0.90.The patients were then subsequently followed up clinically. Kidney function were measured after 1 month, and contrast-enhanced ultrasonography data were obtained at 1 and 3 months later, respectively. The FFR of 1 patient was 0.90, while the FFR of other patients were less than 0.90 before thoracic endovascular aortic repair. After the procedure,the angiography showed that the blood flow of renal artery in 8 patients were fluency, and the FFR index was over 0.90. There were 4 patients with FFR less than 0.90. After renal artery stenting, the FFR of these 4 patients were all above 0.90. Compared with pre-procedure, blood urea nitrogen ((8.84 ± 3.99) mmol/L vs. (5.18 ± 1.69) mmol/L, P = 0.011) and uric acid ((359.3 ± 77.3) µmol/L vs. (276.9 ± 108.3) µmol/L, P = 0.008) decreased significantly after 1 month, and there was no significant difference in serum creatinine (P = 0.760). Contrast-enhanced ultrasonography results showed that blood flow of renal artery were fluency after 1 month and 3 months. In patients with aortic dissection complicating renal blood flow injury, the FFR measurement is meaningful in evaluating the blood flow status of target organs and guide the endovascular revascularization.

Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

Directory of Open Access Journals (Sweden)

Yong-liang LU

2014-09-01

Full Text Available The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice (Chunjiang 016 and Xiushui 09, two inbred indica rice (Zhongzu 14 and Zhongzao 22, two indica hybrid rice (Zhongzheyou 1 and Guodao 1, and one weedy indica rice (Taizhou weedy rice. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows: weedy rice > Chunjiang 016 > Xiushui 09 and Zhongzu 14 > Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and

Enhancing sedimentation by improving flow conditions using parallel retrofit baffles.

Science.gov (United States)

He, Cheng; Scott, Eric; Rochfort, Quintin

2015-09-01

In this study, placing parallel-connected baffles in the vicinity of the inlet was proposed to improve hydraulic conditions for enhancing TSS (total suspended solids) removal. The purpose of the retrofit baffle design is to divide the large and fast inflow into smaller and slower flows to increase flow uniformity. This avoids short-circuiting and increases residence time in the sedimentation basin. The newly proposed parallel-connected baffle configuration was assessed in the laboratory by comparing its TSS removal performance and the optimal flow residence time with those from the widely used series-connected baffles. The experimental results showed that the parallel-connected baffles outperformed the series-connected baffles because it could disperse flow faster and in less space by splitting the large inflow into many small branches instead of solely depending on flow internal friction over a longer flow path, as was the case under the series-connected baffles. Being able to dampen faster flow before entering the sedimentation basin is critical to reducing the possibility of disturbing any settled particles, especially under high inflow conditions. Also, for a large sedimentation basin, it may be more economically feasible to deploy the proposed parallel retrofit baffle in the vicinity of the inlet than series-connected baffles throughout the entire settling basin. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Optimizing resource allocation and patient flow: process analysis and reorganization in three chemotherapy outpatient clinics.

Science.gov (United States)

Holmes, Morgan; Bodie, Kelly; Porter, Geoffrey; Sullivan, Victoria; Tarasuk, Joy; Trembley, Jodie; Trudeau, Maureen

2010-01-01

Optimizing human and physical resources is a major concern for cancer care decision-makers and practitioners. This issue is particularly acute in the context of ambulatory out patient chemotherapy clinics, especially when - as is the case almost everywhere in the industrialized world - the number of people requiring systemic therapy is increasing while budgets, staffing and physical space remain static. Recent initiatives at three hospital-based chemotherapy units - in Halifax, Toronto and Kingston - shed light on the value of process analysis and reorganization for using existing human and physical resources to their full potential, improving patient flow and enhancing patient satisfaction. The steps taken in these settings are broadly applicable to other healthcare settings and would likely result in similar benefits in those environments.

Clinic flow for STI, HIV, and TB patients in an urban infectious disease clinic offering point-of-care testing services in Durban, South Africa.

Science.gov (United States)

Stime, Katrina J; Garrett, Nigel; Sookrajh, Yukteshwar; Dorward, Jienchi; Dlamini, Ntuthu; Olowolagba, Ayo; Sharma, Monisha; Barnabas, Ruanne V; Drain, Paul K

2018-05-11

Many clinics in Southern Africa have long waiting times. The implementation of point-of-care (POC) tests to accelerate diagnosis and improve clinical management in resource-limited settings may improve or worsen clinic flow and waiting times. The objective of this study was to describe clinic flow with special emphasis on the impact of POC testing at a large urban public healthcare clinic in Durban, South Africa. We used time and motion methods to directly observe patients and practitioners. We created patient flow maps and recorded individual patient waiting and consultation times for patients seeking STI, TB, or HIV care. We conducted semi-structured interviews with 20 clinic staff to ascertain staff opinions on clinic flow and POC test implementation. Among 121 observed patients, the total number of queues ranged from 4 to 7 and total visit times ranged from 0:14 (hours:minutes) to 7:38. Patients waited a mean of 2:05 for standard-of-care STI management, and approximately 4:56 for STI POC diagnostic testing. Stable HIV patients who collected antiretroviral therapy refills waited a mean of 2:42 in the standard queue and 2:26 in the fast-track queue. A rapid TB test on a small sample of patients with the Xpert MTB/RIF assay and treatment initiation took a mean of 6:56, and 40% of patients presenting with TB-related symptoms were asked to return for an additional clinic visit to obtain test results. For all groups, the mean clinical assessment time with a nurse or physician was 7 to 9 min, which accounted for 2 to 6% of total visit time. Staff identified poor clinic flow and personnel shortages as areas of concern that may pose challenges to expanding POC tests in the current clinic environment. This busy urban clinic had multiple patient queues, long clinical visits, and short clinical encounters. Although POC testing ensured patients received a diagnosis sooner, it more than doubled the time STI patients spent at the clinic and did not result in same

Teleophthalmology: improving patient outcomes?

Directory of Open Access Journals (Sweden)

Sreelatha OK

2016-02-01

Full Text Available Omana Kesary Sreelatha,1 Sathyamangalam VenkataSubbu Ramesh2 1Ophthalmology Department, Sultan Qaboos University Hospital, Muscat, Oman; 2Department of Optometry, School of Allied Health Sciences, Manipal University, Manipal, India Abstract: Teleophthalmology is gaining importance as an effective eye care delivery modality worldwide. In many developing countries, teleophthalmology is being utilized to provide quality eye care to the underserved urban population and the unserved remote rural population. Over the years, technological innovations have led to improvement in evidence and teleophthalmology has evolved from a research tool to a clinical tool. The majority of the current teleophthalmology services concentrate on patient screening and appropriate referral to experts. Specialty care using teleophthalmology services for the pediatric group includes screening as well as providing timely care for retinopathy of prematurity (ROP. Among geriatric eye diseases, specialty teleophthalmology care is focused toward screening and referral for diabetic retinopathy (DR, glaucoma, age-related macular degeneration (ARMD, and other sight-threatening conditions. Comprehensive vision screening and refractive error services are generally covered as part of most of the teleophthalmology methods. Over the past decades, outcome assessment of health care system includes patients’ assessments on their health, care, and services they receive. Outcomes, by and large, remain the ultimate validators of the effectiveness and quality of medical care. Teleophthalmology produces the same desired clinical outcome as the traditional system. Remote portals allow specialists to provide care over a larger region, thereby improving health outcomes and increasing accessibility of specialty care to a larger population. A high satisfaction level and acceptance is reported in the majority of the studies because of increased accessibility and reduced traveling cost and time

Performance Improvement Of Cross-Flow Filtration For High Level Waste Treatment

International Nuclear Information System (INIS)

Duignan, M.; Nash, C.; Poirier, M.

2011-01-01

In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT

Energy Technology Data Exchange (ETDEWEB)

Duignan, M.; Nash, C.; Poirier, M.

2011-01-12

In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed

Developing models for patient flow and daily surge capacity research.

Science.gov (United States)

Asplin, Brent R; Flottemesch, Thomas J; Gordon, Bradley D

2006-11-01

Between 1993 and 2003, visits to U.S. emergency departments (EDs) increased by 26%, to a total of 114 million visits annually. At the same time, the number of U.S. EDs decreased by more than 400, and almost 200,000 inpatient hospital beds were taken out of service. In this context, the adequacy of daily surge capacity within the system is clearly an important issue. However, the research agenda on surge capacity thus far has focused primarily on large-scale disasters, such as pandemic influenza or a serious bioterrorism event. The concept of daily surge capacity and its relationship to the broader research agenda on patient flow is a relatively new area of investigation. In this article, the authors begin by describing the overlap between the research agendas on daily surge capacity and patient flow. Next, they propose two models that have potential applications for both daily surge capacity and hospitalwide patient-flow research. Finally, they identify potential research questions that are based on applications of the proposed research models.

Assessment of intracardiac flow and vorticity in the right heart of patients after repair of tetralogy of Fallot by flow-sensitive 4D MRI.

Science.gov (United States)

Hirtler, Daniel; Garcia, Julio; Barker, Alex J; Geiger, Julia

2016-10-01

To comprehensively and quantitatively analyse flow and vorticity in the right heart of patients after repair of tetralogy of Fallot (rTOF) compared with healthy volunteers. Time-resolved flow-sensitive 4D MRI was acquired in 24 rTOF patients and 12 volunteers. Qualitative flow evaluation was based on consensus reading of two observers. Quantitative analysis included segmentation of the right atrium (RA) and ventricle (RV) in a four-chamber view to extract volumes and regional haemodynamic information for computation of regional mean and peak vorticity. Right heart intra-atrial, intraventricular and outflow tract flow patterns differed considerably between rTOF patients and volunteers. Peak RA and mean RV vorticity was significantly higher in patients (p = 0.02/0.05). Significant negative correlations were found between patients' maximum and mean RV and RA vorticity and ventricular volumes (p tetralogy of Fallot. • Regurgitant flow in the main pulmonary artery is associated with higher right heart vorticity.

Requirements and benefits of flow forecasting for improving hydropower generation

NARCIS (Netherlands)

Dong, Xiaohua; Vrijling, J.K.; Dohmen-Janssen, Catarine M.; Ruigh, E.; Booij, Martijn J.; Stalenberg, B.; Hulscher, Suzanne J.M.H.; van Gelder, P.H.A.J.M.; Verlaan, M.; Zijderveld, A.; Waarts, P.

2005-01-01

This paper presents a methodology to identify the required lead time and accuracy of flow forecasting for improving hydropower generation of a reservoir, by simulating the benefits (in terms of electricity generated) obtained from the forecasting with varying lead times and accuracies. The

Cerebrospinal fluid flow abnormalities in patients with neoplastic meningitis. An evaluation using 111In-DTPA ventriculography

International Nuclear Information System (INIS)

Grossman, S.A.; Trump, D.L.; Chen, D.C.; Thompson, G.; Camargo, E.E.

1982-01-01

Cerebrospinal fluid flow dynamics were evaluated by 111 In-diethylenetriamine pentaacetic acid ( 111 In-DTPA) ventriculography in 27 patients with neoplastic meningitis. Nineteen patients (70 percent) had evidence of cerebrospinal fluid flow disturbances. These occurred as ventricular outlet obstructions, abnormalities of flow in the spinal canal, or flow distrubances over the cortical convexities. Tumor histology, physical examination, cerebrospinal fluid analysis, myelograms, and computerized axial tomographic scans were not sufficient to predict cerebrospinal fluid flow patterns. These data indicate that cerebrospinal fluid flow abnormalities are common in patients with neoplastic meningitis and that 111 In-DTPA cerebrospinal fluid flow imaging is useful in characterizing these abnormalities. This technique provides insight into the distribution of intraventricularly administered chemotherapy and may provide explanations for treatment failure and drug-induced neurotoxicity in patients with neoplastic meningitis

Long-term, regular remote ischemic preconditioning improves endothelial function in patients with coronary heart disease

Energy Technology Data Exchange (ETDEWEB)

Liang, Y.; Li, Y.P.; He, F.; Liu, X.Q.; Zhang, J.Y. [Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou (China)

2015-04-28

Remote ischemic preconditioning (RIPre) can prevent myocardial injury. The purpose of this study was to assess the beneficial effects of long-term regular RIPre on human arteries. Forty patients scheduled for coronary artery bypass graft (CABG) surgery were assigned randomly to a RIPre group (n=20) or coronary heart disease (CHD) group (n=20). Twenty patients scheduled for mastectomy were enrolled as a control group. RIPre was achieved by occluding arterial blood flow 5 min with a mercury sphygmomanometer followed by a 5-min reperfusion period, and this was repeated 4 times. The RIPre procedure was repeated 3 times a day for 20 days. In all patients, arterial fragments discarded during surgery were collected to evaluate endothelial function by flow-mediated dilation (FMD), CD34{sup +} monocyte count, and endothelial nitric oxide synthase (eNOS expression). Phosphorylation levels of STAT-3 and Akt were also assayed to explore the underlying mechanisms. Compared with the CHD group, long-term regular RIPre significantly improved FMD after 20 days (8.5±2.4 vs 4.9±4.2%, P<0.05) and significantly reduced troponin after CABG surgery (0.72±0.31 and 1.64±0.19, P<0.05). RIPre activated STAT-3 and increased CD34{sup +} endothelial progenitor cell counts found in arteries. Long-term, regular RIPre improved endothelial function in patients with CHD, possibly due to STAT-3 activation, and this may have led to an increase in endothelial progenitor cells.

Prevalence of xerostomia and the salivary flow rate in diabetic patients.

Science.gov (United States)

Malicka, Barbara; Kaczmarek, Urszula; Skośkiewicz-Malinowska, Katarzyna

2014-01-01

Diabetes is a metabolic disease characterized by hyperglycemia, which results from relative or absolute insulin deficiency. One of the first oral symptoms of diabetes is xerostomia. The aim of the study was to determine the prevalence of the xerostomia symptoms and salivary flow rate in diabetic patients according to the type of diabetes, the level of metabolic control and the duration of the disease. The study involved 156 adult patients of both sexes including 34 patients with diabetes type 1 (group C1), 59 with diabetes type 2 (group C2), and 63 generally healthy individuals as two control groups, sex- and age-matched to the diabetic group. The patients suffering from both types of diabetes were additionally subdivided according to the level of metabolic control and the duration of the disease. Xerostomia was diagnosed with the use of a specially prepared questionnaire and Fox's test. Moreover, the salivary flow rate of resting mixed saliva was measured. In type 1 diabetics, a significantly lower salivary flow rate in comparison to the age-matched control group (0.38 ± 0.19 mL/min vs. 0.53 ± 0.20 mL/min, p diabetics, a slight lower salivary flow rate was noticed (on average, 20% lower). Dry mouth was far more frequently diagnosed in type 1 diabetics than in the control group. In type 1 diabetics, in comparison to healthy subjects, a significantly lower resting flow rate of saliva and significantly higher prevalence of xerosomia were observed, but in type 2 diabetics, only a trend of such variability was observed.

Coronary blood flow and coronary stenosis correlations in ischemic heart patients

International Nuclear Information System (INIS)

Manukov, I.

2003-01-01

The aim of the study is the assessment of the methodology for the C-TIMI frame count by Gibson for easy and fast determination of the coronary blood flow during a selective coronary angiography. 75 patient have been studied with one-branch affection of the coronary arteries. The criteria for exclusion are: myocardial hypertrophy, valve lesions, myocardial infarction and dyslipidemia. Depending of the characteristics of the coronary stenotic changes, the patients have been divided into two groups: 1) Patients with 'ordinary' stenosis of the coronary artery and 2) Patients with 'complex' stenosis. The severity of the stenotic changes in percents is the same for the two groups - 78%±13% vs 81±12%, respectively. In the first group a pronounced correlation is observed between the severity of the coronary stenosis and the slowing of the coronary blood flow. The 'threshold' stenotic level is 89%. In the second group the lowest value of the coronary stenosis is 73% (p>0.01 vs group 1). No correlation is observed between the severity of the coronary stenosis and the slowing of the coronary blood flow. A conclusion is made that the Gibson method for the assessment of the blood flow is convenient for the daily practice not only for the assessment of the significance of the coronary changes, but also for fast analysis of the achieved reconstruction of the coronary arteries after angioplasty. Additional studies of the significance of the different signs of 'complexity' of the coronary stenosis for the slowing of the blood flow are necessary

Low regional cerebral blood flow in burning mouth syndrome patients with depression.

Science.gov (United States)

Liu, B-L; Yao, H; Zheng, X-J; Du, G-H; Shen, X-M; Zhou, Y-M; Tang, G-Y

2015-07-01

The main aims of this study were to (i) investigate the emotional disorder status of patients with burning mouth syndrome (BMS) and (ii) detect regional cerebral blood flow in BMS patients with the application of combined single-photon emission computed tomography and computed tomography (SPECT/CT). The degree of pain was measured using the visual analysis scale, and emotional disorder with the self-rating anxiety scale, self-rating depression scale, and Hamilton depression rating scale in 29 patients with BMS and 10 healthy controls. SPECT/CT was performed in 29 patients with BMS and 10 healthy controls, and statistical parametric mapping method was used for between-group analyses. The incidence rate of depression in patients with BMS was 31.0%. Compared to the control group, patients with BMS displayed significantly different depression and anxiety scales (P < 0.05). Significantly lower regional cerebral blood flow in the left parietal and left temporal lobes was recorded for BMS patients with depression (P < 0.05). Patients with BMS experience more depression and anxious emotion. Moreover, depression in patients with BMS may be associated with lower regional cerebral blood flow in the left temporal and left parietal lobes. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Improving Value for Patients with Eczema.

Science.gov (United States)

Block, Julie

2018-04-01

Chronic diseases now represent a cost majority in the United States health care system. Contributing factors to rising costs include expensive novel and emerging therapies, under-treatment of disease, under-management of comorbidities, and patient dissatisfaction with care results. Critical to identifying replicable improvement methods is a reliable model to measure value. If we understand value within healthcare consumerism to be equal to a patient's health outcome improvement over costs associated with care (Value=Outcomes/Costs), we can use this equation to measure the improvement of value. Research and literature show that patient activation-the skills and confidence that equip patients to become actively engaged in their health care-impact health outcomes, costs, and patient experience. Reaching patient activation through engagement methods including shared decision-making (SDM) lead to improved value of care received. The National Eczema Association (NEA) Shared Decision-Making Resource Center can be a transformative strategy to measure and evaluate value of health care interventions for eczema patients to advance a value-driven health care system in the United States. Through this Resource Center, NEA will measure patient value through their own perceptions using validated PRO instruments and other patient-generated health data. Assessment of this data will reveal findings that can assist researchers in evaluating the impact this care framework on patient-perceived value across other chronic diseases. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Neuropsychological improvement in patients with cervical spondylotic myelopathy after posterior decompression surgery

International Nuclear Information System (INIS)

Hoshimaru, Minoru

2010-01-01

Patients with cervical spondylotic myelopathy sometimes complain of cognitive dysfunction, which may be coincidence. However, cognitive dysfunction may be related to disorders of the cervical spine and/or spinal cord. This study investigated cognitive dysfunction in patients with cervical spinal disorders. A total of 79 patients with cervical spondylotic myelopathy (40 women and 39 men, mean age 61.2 years) underwent cervical laminoplasty between January 2006 and July 2007. Ten of these 79 patients (7 women and 3 men, mean age 65.2 years) complained of moderate to severe memory disturbances. These 10 patients underwent neuroimaging studies and a battery of neuropsychological tests consisting of the mini-mental state examination, Kohs Block Design Test, Miyake Memory Test, Benton Visual Retention Test (BVRT), and 'kana-hiroi' test before and 3 months after surgery. Brain magnetic resonance imaging showed no organic brain lesions in the 10 patients, but single photon emission computed tomography demonstrated reduced regional cerebral blood flow in the posterior cortical areas in eight patients before surgery. Neuropsychological test scores showed statistically significant improvement after surgery in the Kohs Block Design Test and the BVRT, which measure visuospatial perception and reflect the function of the parietal and/or occipital lobes (p<0.05). The practice effect may have contributed to the neuropsychological improvements, but this study suggests that cervical spinal disorders may affect cognitive functions and that surgical treatment can ameliorate such effects. (author)

Effect of strict metabolic control on regulation of subcutaneous blood flow in insulin-dependent diabetic patients

DEFF Research Database (Denmark)

Kastrup, J; Mathiesen, E R; Saurbrey, Nina

1987-01-01

washout technique. Mean arterial blood pressure was reduced by a maximum of 23 mmHg by elevating the limb above heart level and elevated to a maximum of 65 mmHg by head-up tilt; in the latter position venous pressure was kept constantly low by activation of the leg muscle vein pump (heel raising......The effect of 10 weeks of improved metabolic control on the impaired autoregulation of the subcutaneous blood flow was studied at the level of the lateral malleolus in eight long-term insulin-dependent diabetic patients with clinical microangiopathy. Blood flow was measured by the local 133-Xenon......). Improved metabolic control was achieved using either continuous subcutaneous insulin infusion or multiple insulin injections. The blood glucose concentration declined from (median) 12.7 to 6.8 mmol/l and the HbA1C level from 10.1 to 7.5% during strict metabolic control (p less than 0.01 and p less than 0...

Efficacy of blood flow restriction exercise during dialysis for end stage kidney disease patients: protocol of a randomised controlled trial.

Science.gov (United States)

Clarkson, Matthew J; Fraser, Steve F; Bennett, Paul N; McMahon, Lawrence P; Brumby, Catherine; Warmington, Stuart A

2017-09-11

Exercise during haemodialysis improves strength and physical function. However, both patients and clinicians are time poor, and current exercise recommendations add an excessive time burden making exercise a rare addition to standard care. Hypothetically, blood flow restriction exercise performed during haemodialysis can provide greater value for time spent exercising, reducing this time burden while producing similar or greater outcomes. This study will explore the efficacy of blood flow restriction exercise for enhancing strength and physical function among haemodialysis patients. This is a randomised controlled trial design. A total of 75 participants will be recruited from haemodialysis clinics. Participants will be allocated to a blood flow restriction cycling group, traditional cycling group or usual care control group. Both exercising groups will complete 3 months of cycling exercise, performed intradialytically, three times per week. The blood flow restriction cycling group will complete two 10-min cycling bouts separated by a 20-min rest at a subjective effort of 15 on a 6 to 20 rating scale. This will be done with pressurised cuffs fitted proximally on the active limbs during exercise at 50% of a pre-determined limb occlusion pressure. The traditional cycling group will perform a continuous 20-min bout of exercise at a subjective effort of 12 on the same subjective effort scale. These workloads and volumes are equivalent and allow for comparison of a common blood flow restriction aerobic exercise prescription and a traditional aerobic exercise prescription. The primary outcome measures are lower limb strength, assessed by a three repetition maximum leg extension test, as well as objective measures of physical function: six-minute walk test, 30-s sit to stand, and timed up and go. Secondary outcome measures include thigh muscle cross sectional area, body composition, routine pathology, quality of life, and physical activity engagement. This study will

The effect of combined treatment with transcranial direct current stimulation on cerebral blood flow in patients with cerebral palsy

Directory of Open Access Journals (Sweden)

K. V. Yatsenko

2017-02-01

Full Text Available There is a close link between the activity of the brain and cerebral blood supply. Transcranial direct current stimulation (tDCS modulates the activity of the cerebral cortex and thus affects the cerebral blood flow. The aim of the study was to investigate the effect of combined treatment with tDCS on cerebral blood flow in patients with cerebral palsy (CP. Materials and Methods. 60 patients with various forms of cerebral palsy were examined and received the course of treatment. The comparison group was formed from 30 children who received the course of basic medical and rehabilitation procedures. The main group included 30 children who, in addition to the same therapy, received a course of tDCS. A transcranial Doppler ultrasound examination of head blood vessels was used for the study of cerebral hemodynamics in children with cerebral palsy before and after combined treatment with tDCS. Results. tDCS reduced asymmetry coefficient of blood flow velocity in the middle cerebral arteries (MCA by 12.3 %, whereas in the comparison group only by 2.5 %; in the anterior cerebral artery (ACA – 9.5 %, while in the comparison group – 0.8 %. tDCS significantly reduced the high mean blood flow velocity per cycle (MFV in the basilar artery (BA, MCA and ACA (21.7 %, 18.3 % and 7.8 %, respectively; in the comparison group no statistically significant positive dynamics was observed. tDCS significantly increased the low MVF in the BA, MCA and ACA (29.7 %, 21.2 % and 9.7 % respectively; a statistically significant increase of MVF by 9.9 % was only in the CMA in the comparison group of patients. Conclusions. Our data indicate that the use of tDCS in the combined treatment of CP patients improves cerebral hemodynamics in 87 % of patients, in contrast to 52 % in the comparison group. The addition of transcranial direct current stimulation method to the complex treatment of patients with cerebral palsy improves the effectiveness of treatment and may also

Reduction in exhaled nitric oxide tracks improved patient inhaler compliance in difficult asthma-a case study.

Science.gov (United States)

Hunt, Eoin; Flynn, Deirdre; MacHale, Elaine; Costello, Richard W; Murphy, Desmond M

2017-12-26

Exhaled nitric oxide is believed be a useful surrogate for airways inflammation while non-adherence with therapy is known to be associated with worsening of asthma control. We present the case of a 49-year-old female with steroid-dependent asthma and an exacerbation rate of >20/year. She was enrolled in a 3-month-long prospective study using a validated diagnostic inhaler device that provided objective evidence of inhaler compliance. Fractional exhaled nitric oxide (FeNO), peak expiratory flow rates, asthma control questionnaires were measured throughout the study period. Peripheral eosinophil count was obtained prior to the study, during the study, and immediately afterwards. Improvement in compliance at the end of the study led to significant improvements in lung function peak expiratory flow rate (PEFR), and objective scores of asthma. There was an observed improvement in PEFR after 4 weeks, with an associated decrease in FeNO from 92 to 9 ppb that plateaued over the remainder of the study. Her eosinophil count was 0.79 × 10 9 /litre prior to starting in the study, 0.37 × 10 9 /litre after 2 months, and 0.1 × 10 9 /litre at the end of the study. We believe that this is the first case study to objectively prove that improvements in compliance can lead to dramatic reductions in the overall inflammatory airway response and in particular that improvements in patient compliance are mirrored by marked reduction in FeNO levels. These changes occurred in tandem with an observed clinical improvement in our patient.

Cerebral blood flow and metabolism of the patients with a carotid stenosis evaluated by SPECT and 1H-MRS

International Nuclear Information System (INIS)

Uno, Masaaki; Nishi, Kyouko; Shinno, Kiyohito; Nagahiro, Shinji; Ohtsuka, Hideki; Harada, Masafumi

1998-01-01

We examined cerebral blood flow (CBF) and metabolic states in patients with a severe carotid stenosis by SPECT and proton MRS ( 1 H-MRS). SPECT using 99m Tc-HMPAO and 1 H-MRS were performed in twenty five patients with over 70% carotid stenosis. Moreover, 10 patients were evaluated by these methods after carotid endarterectomy (CEA). N-acetyl-aspartate (NAA) on the ipsilateral side was reduced in 17 patients (Group A) while NAA of other 8 patients was not reduced (Group B). In Group A, although regional CBF was reduced in only 4 of 17 patients, 11 patients showed decline of cerebral vasoreactivity evaluated by acetazolamide injection. Concentration of NAA and regional CBF showed significant correlations. After CEA, ipsilateral NAA was increased significantly compared to preoperative NAA level. In 6 of 7 patients in Group A, cerebral vasoreactivity also improved postoperatively. These results indicated that ipsilatereal NAA metabolism and cerebral vasoreactivity can be improved after CEA. SPECT and 1 H-MRS were useful to evaluate CBF and metabolism in patients with carotid stenosis. (author)

Regional cerebral flows in hypertensive patients

International Nuclear Information System (INIS)

Britton, K.E.; Granowska, M.; Lee, T.Y.; Nimmon, C.C.; Rutland, M.

1978-01-01

The aim of this study is to develop a method for assessing the natural history of cerebrovascular disease in patients with hypertension in order that the effects of controlling hypertension may be judged. By developing a quantitative noninvasive method for measuring regional cerebral flow and internal carotid appearance times it is hoped that drugs intended to inhibit the continued formation of atheroma and drugs intended to aid the dissolution of atheroma, may be objectively evaluated. (Auth.)

Fractional flow reserve guided percutaneous coronary intervention results in reduced ischemic myocardium and improved outcomes.

Science.gov (United States)

Sawant, Abhishek C; Bhardwaj, Aishwarya; Banerjee, Kinjal; Jobanputra, Yash; Kumar, Arnav; Parikh, Parth; Kandregula, Krishna C; Poddar, Kanhaiya; Ellis, Stephen G; Nair, Ravi; Corbelli, John; Kapadia, Samir

2018-02-06

To determine if fractional flow reserve guided percutaneous coronary intervention (FFR-guided PCI) is associated with reduced ischemic myocardium compared with angiography-guided PCI. Although FFR-guided PCI has been shown to improve outcomes, it remains unclear if it reduces the extent of ischemic myocardium at risk compared with angiography-guided PCI. We evaluated 380 patients (190 FFR-guided PCI cases and 190 propensity-matched controls) who underwent PCI from 2009 to 2014. Clinical, laboratory, angiographic, stress testing, and major adverse cardiac events [MACE] (all-cause mortality, recurrence of MI requiring PCI, stroke) data were collected. Mean age was 63 ± 11 years; the majority of patients were males (76%) and Caucasian (77%). Median duration of follow up was 3.4 [Range: 1.9, 5.0] years. Procedural complications including coronary dissection (2% vs. 0%, P = .12) and perforation (0% vs. 0%, P = 1.00) were similar between FFR-guided and angiography-guided PCI patients. FFR-guided PCI patients had lower unadjusted (14.7% vs. 23.2%, P = .04) and adjusted [OR = 0.58 (95% CI: 0.34-0.98)] risk of repeat revascularization at one year. FFR-guided PCI patients were less likely (23% vs. 32%, P = .02) to have ischemia and had lower (5.9% vs. 21.1%, P guided PCI, FFR-guided PCI results in less repeat revascularization and a lower incidence of post PCI ischemia translating into improved survival, without an increase in complications. © 2018 Wiley Periodicals, Inc.

Improved Design of PECS to reduce Flow Instability for EU-APR1400

International Nuclear Information System (INIS)

Hwang, Do Hyun; Lee, Keunsung

2014-01-01

For EU-APR1400, PECS (Passive Ex-vessel corium retaining and Cooling System), so-called core catcher, was adopted to keep the integrity of basemat in containment by preventing MCCI (Molten Core Concrete Interaction) through retaining core debris and cooling corium outside the reactor vessel. In this paper, the improved design of PECS is presented to increase coolability by reducing flow instability in the region of cooling channel. In this paper, flow instability analysis was carried out using CFD code to find out the most improved design of PECS, which is to increase coolability by reducing bubble entrainment in the region of cooling channel. The reduction of bubble entrainment in the downcomer facilitates higher mass flow rates in the downcomer. Among presented four designed for the downcomer of PECS, the superstep design shows the highest mass flow rate and the lowest gas holdup in the downcomer as well as in the cooling channel. Compared with the existing design, the elimination of the horizontal part and the addition of an extra space above the vertical entrance to the downcomer seem to help the separation of the vapor

Determination of pump flow rate during cardiopulmonary bypass in obese patients avoiding hemodilution.

Science.gov (United States)

Santambrogio, Luisa; Leva, Cristian; Musazzi, Giorgio; Bruno, Piergiorgio; Vailati, Andrea; Zecchillo, Franco; Di Credico, Germano

2009-01-01

During cardiopulmonary bypass the pump flow is usually set on 2.4 L/min/m(2) of body surface area (BSA) to guarantee adequate tissue perfusion without differences for patient constitutional type. The present study attempts to evaluate the adequacy of pump flow rate in obese patients, considering the ideal weight instead of the real one, avoiding the overflow side effects and hemodilution. Obese patients with body mass index (BMI) > 30 presented for cardiac surgery were randomized in two groups: in one the cardiopulmonary bypass was led traditionally, in the other, pump flow rate was calculated on ideal BMI of 25. Demographics, preoperative tests, and monitoring data were registered. Mortality at hospital discharge and 30 days after were analyzed. The pump flow rate between the groups was different (4.46 vs. 4.87; p = 0.004); there were no differences in organ perfusion (SvO(2); diuresis) and mortality, but the study group presented fewer complications and blood transfusions. The BSA is widely used as the biometric unit to normalize physiologic parameters included pump flow rate, but it is disputable if this practice is correct also in obese patients. The study group, in which pump flow rate was set on ideal BSA, presented no difference in diuresis and mixed venous saturation but fewer complications and fewer perioperative blood transfusions.

Cine-MR imaging aqueductal CSF flow in normal pressure hydrocephalus syndrome before and after CSF shunt

International Nuclear Information System (INIS)

Mascalchi, M.; Arnetoli, G.; Inzitari, D.; Dal Pozzo, G.; Lolli, F.; Caramella, D.; Bartolozzi, C.

1993-01-01

Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction. (orig.)

Improvements to a Flow Sensor for Liquid Bismuth-Fed Hall Thrusters

Science.gov (United States)

Bonds, Kevin; Polzin, Kurt A.

2010-01-01

Recently, there has been significant interest in using bismuth metal as a propellant in Hall Thrusters [1, 2]. Bismuth offers some considerable cost, weight, and space savings over the traditional propellant--xenon. Quantifying the performance of liquid metal-fed Hall thrusters requires a very precise measure of the low propellant flow rates [1, 2]. The low flow rates (10 mg/sec) and the temperature at which free flowing liquid bismuth exists (above 300 C) preclude the use of off-the-shelf flow sensing equipment [3]. Therefore a new type of sensor is required. The hotspot bismuth flow sensor, described in Refs. [1-5] is designed to perform a flow rate measurement by measuring the velocity at which a thermal feature moves through a flow chamber. The mass flow rate can be determined from the time of flight of the thermal peak, [4, 5]. Previous research and testing has been concerned mainly with the generation of the thermal peak and it's subsequent detection. In this paper, we present design improvements to the sensor concept; and the results of testing conducted to verify the functionality of these improvements. A ceramic material is required for the sensor body (see Fig. 1), which must allow for active heating of the bismuth flow channel to keep the propellant in a liquid state. The material must be compatible with bismuth and must be bonded to conductive elements to allow for conduction of current into the liquid metal and measurement of the temperature in the flow. The new sensor requires fabrication techniques that will allow for a very small diameter flow chamber, which is required to produce useful measurements. Testing of various materials has revealed several that are potentially compatible with liquid bismuth. Of primary concern in the fabrication and testing of a robust, working prototype, is the compatibility of the selected materials with one another. Specifically, the thermal expansion rates of the materials relative to the ceramic body cannot expand so

Performance evaluation of FlowCytomix assays to quantify cytokines in patients with rheumatoid arthritis

Science.gov (United States)

Wang, Xuefeng; Dong, Liyang; Liang, Yong; Ni, Hongchang; Tang, Jun; Xu, Chengcheng; Zhou, Yuepeng; Su, Yuting; Wang, Jun; Chen, Deyu; Mao, Chaoming

2015-01-01

Objectives: To compare the cytokine profile in RA patients and healthy control by using two methods-FlowCytomix assay and traditional ELISA. Methods: Cytokine levels were evaluated by FlowCytomix assay and ELISA in serum and supernatants of peripheral blood mononuclear cells (PBMC) cultures with and without stimulation by phytohaemagglutinin (PHA). Results: The levels of IL-6, IL-1β, and TNF-α were significantly higher in sera of RA patients than those of healthy controls. The levels of IL-22, IL-6, IL-1β, TNF-α, and IL-10 were higher in unstimulated PBMC culture supernatant of RA patients than those of healthy controls. PHA stimulation significantly increased the production of proinflammatory cytokines from PBMC with RA patients. Compared with detectable cytokine levels in sera, cytokine concentration in the supernatant of PBMCs was remarkably higher. FlowCytomix and ELISA showed significant correlation in detecting cytokines. However, the FlowCytomix assay detected more cytokines than ELISA. Conclusion: The supernatant of PBMCs provide a fine condition for the study of cytokine production because of the lack of interference factors in sera. The FlowCytomix assay is more sensitive than ELISA in detecting cytokines from RA patients. Multiple cytokine signatures using FlowCytomix assay may represent a more realistic approach in the future of personalized medicine in RA. PMID:26629129

Improved dynamic CT angiography visualization by flow territory masking

Directory of Open Access Journals (Sweden)

Søren Christensen

2015-01-01

Full Text Available Backgound and Purpose: Computerized tomography (CT perfusion (or CTP source images from CT scanners with small detector widths can be used to create a dynamic CT angiogram (CTA similar to digital subtraction angiography (DSA. Because CTP studies use a single intravenous injection, all arterial territories enhance simultaneously, and individual arterial territories [i.e., anterior cerebral artery (ACA, middle cerebral artery (MCA, and posterior cerebral artery (PCA] cannot be delineated. This limits the ability to assess collateral flow patterns on dynamic CTAs. The aim of this study was to devise and test a postprocessing method to selectively color-label the major arterial territories on dynamic CTA. Materials and Methods: We identified 22 acute-stroke patients who underwent CTP on a 320-slice CT scanner within 6 h from symptom onset. For each case, two investigators independently generated an arterial territory map from CTP bolus arrival maps using a semiautomated method. The volumes of the arterial territories were calculated for each map and the average relative difference between these volumes was calculated for each case as a measure of interrater agreement. Arterial territory maps were superimposed on the dynamic CTA to create a vessel-selective dynamic CTA with color-coding of the main arterial territories. Two experts rated the arterial territory maps and the color-coded CTAs for consistency with expected arterial territories on a 3-point scale (excellent, moderate, poor. Results: Arterial territory maps were generated for all 22 patients. The median difference in arterial territory volumes between investigators was 2.2% [interquartile range (IQR 0.6-8.5%]. Based on expert review, the arterial territory maps and the vessel-selective dynamic CTAs showed excellent consistency with the expected arterial territories in 18 of 22 patients, moderate consistency in 2 patients, and poor consistency in another 2 patients. Conclusion: Using a

Validation of Patient-Specific Cerebral Blood Flow Simulation Using Transcranial Doppler Measurements

Directory of Open Access Journals (Sweden)

Derek Groen

2018-06-01

Full Text Available We present a validation study comparing results from a patient-specific lattice-Boltzmann simulation to transcranial Doppler (TCD velocity measurements in four different planes of the middle cerebral artery (MCA. As part of the study, we compared simulations using a Newtonian and a Carreau-Yasuda rheology model. We also investigated the viability of using downscaled velocities to reduce the required resolution. Simulations with unscaled velocities predict the maximum flow velocity with an error of less than 9%, independent of the rheology model chosen. The accuracy of the simulation predictions worsens considerably when simulations are run at reduced velocity, as is for example the case when inflow velocities from healthy individuals are used on a vascular model of a stroke patient. Our results demonstrate the importance of using directly measured and patient-specific inflow velocities when simulating blood flow in MCAs. We conclude that localized TCD measurements together with predictive simulations can be used to obtain flow estimates with high fidelity over a larger region, and reduce the need for more invasive flow measurement procedures.

An improved ghost-cell immersed boundary method for compressible flow simulations

KAUST Repository

Chi, Cheng; Lee, Bok Jik; Im, Hong G.

2016-01-01

This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary

Xerostomia, Hyposalivation, and Salivary Flow in Diabetes Patients

OpenAIRE

L?pez-Pintor, Rosa Mar?a; Casa?as, Elisabeth; Gonz?lez-Serrano, Jos?; Serrano, Julia; Ram?rez, Luc?a; de Arriba, Lorenzo; Hern?ndez, Gonzalo

2016-01-01

The presence of xerostomia and hyposalivation is frequent among diabetes mellitus (DM) patients. It is not clear if the presence of xerostomia and hyposalivation is greater in DM than non-DM patients. The aims of this systematic review are (1) to compare the prevalence rates of xerostomia, (2) to evaluate the salivary flow rate, and (3) to compare the prevalence rates of hyposalivation in DM versus non-DM population. This systematic review was conducted according to the PRISMA group guideline...

Salivary flow and xerostomia in older patients with type 2 diabetes mellitus.

Science.gov (United States)

Lima, Danilo Lopes Ferreira; Carneiro, Sandro Dias Rocha Mendes; Barbosa, Fladia Taciana de Sousa; Saintrain, Maria Vieira de Lima; Moizan, Jean André Hervé; Doucet, Jean

2017-01-01

To assess salivary flow in older patients with type 2 diabetes mellitus (DM2) and its association with xerostomia. Cross-sectional clinical study conducted with older patients diagnosed with type 2 diabetes for at least one year receiving treatment at the Integrated Center for Diabetes and Hypertension of Ceará (CIHD) in the city of Fortaleza, Ceará, Northeastern Brazil. Oral clinical examination was carried out to assess the decayed, missing and filled teeth index (DMFT). Perception of the presence of xerostomia/dry mouth was assessed using the Visual Analogue Scale. Stimulated salivary flow was measured and samples were obtained using an extra-soft silicone device. 120 older patients with diabetes (60 insulin-dependent and 60 non-insulin-dependent) aged 65-91 years, with a mean age of 72.26 ± 6.53 years, were assessed. Of these, 111 (92.5%) presented a decrease in salivary flow while 59 (49.2%) reported moderate to severe xerostomia/dry mouth. The DMFT Index presented a mean of 27.53 ± 4.86 teeth. Reduced salivary flow was found in the group assessed in the present research; however, this finding is not in accordance with the perception of xerostomia/dry mouth reported by the patients.

Salivary flow and xerostomia in older patients with type 2 diabetes mellitus.

Directory of Open Access Journals (Sweden)

Danilo Lopes Ferreira Lima

Full Text Available To assess salivary flow in older patients with type 2 diabetes mellitus (DM2 and its association with xerostomia.Cross-sectional clinical study conducted with older patients diagnosed with type 2 diabetes for at least one year receiving treatment at the Integrated Center for Diabetes and Hypertension of Ceará (CIHD in the city of Fortaleza, Ceará, Northeastern Brazil. Oral clinical examination was carried out to assess the decayed, missing and filled teeth index (DMFT. Perception of the presence of xerostomia/dry mouth was assessed using the Visual Analogue Scale. Stimulated salivary flow was measured and samples were obtained using an extra-soft silicone device.120 older patients with diabetes (60 insulin-dependent and 60 non-insulin-dependent aged 65-91 years, with a mean age of 72.26 ± 6.53 years, were assessed. Of these, 111 (92.5% presented a decrease in salivary flow while 59 (49.2% reported moderate to severe xerostomia/dry mouth. The DMFT Index presented a mean of 27.53 ± 4.86 teeth.Reduced salivary flow was found in the group assessed in the present research; however, this finding is not in accordance with the perception of xerostomia/dry mouth reported by the patients.

Mortality in patients with TIMI 3 flow after PCI in relation to time delay to reperfusion.

Science.gov (United States)

Vichova, Teodora; Maly, Marek; Ulman, Jaroslav; Motovska, Zuzana

2016-03-01

Percutaneous coronary intervention (PCI) performed within 12 h from symptom onset enables complete blood flow restoration in infarct-related artery in 90% of patients. Nevertheless, even with complete restoration of epicardial blood flow in culprit vessel (postprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade 3), myocardial perfusion at tissue level may be insufficient. We hypothesized that the outcome of patients with STEMI/bundle branch block (BBB)-myocardial infarction and post-PCI TIMI 3 flow is related to the time to reperfusion. Observational study based on a retrospective analysis of population of 635 consecutive patients with STEMI/BBB-MI and post-PCI TIMI 3 flow from January 2009 to December 2011 (mean age 63 years, 69.6% males). Mortality of patients was evaluated in relation to the time from symptom onset to reperfusion. A total of 83 patients (13.07%) with postprocedural TIMI 3 flow after PCI had died at 1-year follow-up. Median TD in patients who survived was 3.92 h (iqr 5.43), in patients who died 6.0 h (iqr 11.42), P = 0.004. Multiple logistic regression analysis identified time delay ≥ 9 h as significantly related to 1-year mortality of patients with STEMI/BBB-MI and post-PCI TIMI 3 flow (OR 1.958, P = 0.026). Other significant variables associated with mortality in multivariate regression analysis were: left ventricle ejection fraction 65 years (P 2 (P PCI.

Using screen-based simulation of inhaled anaesthetic delivery to improve patient care.

Science.gov (United States)

Philip, J H

2015-12-01

Screen-based simulation can improve patient care by giving novices and experienced clinicians insight into drug behaviour. Gas Man(®) is a screen-based simulation program that depicts pictorially and graphically the anaesthetic gas and vapour tension from the vaporizer to the site of action, namely the brain and spinal cord. The gases and vapours depicted are desflurane, enflurane, ether, halothane, isoflurane, nitrogen, nitrous oxide, sevoflurane, and xenon. Multiple agents can be administered simultaneously or individually and the results shown on an overlay graph. Practice exercises provide in-depth knowledge of the subject matter. Experienced clinicians can simulate anaesthesia occurrences and practices for application to their clinical practice, and publish the results to benefit others to improve patient care. Published studies using this screen-based simulation have led to a number of findings, as follows: changing from isoflurane to desflurane toward the end of anaesthesia does not accelerate recovery in humans; vital capacity induction can produce loss of consciousness in 45 s; simulated context-sensitive decrement times explain recovery profiles; hyperventilation does not dramatically speed emergence; high fresh gas flow is wasteful; fresh gas flow and not the vaporizer setting should be reduced during intubation; re-anaesthetization can occur with severe hypoventilation after extubation; and in re-anaesthetization, the anaesthetic redistributes from skeletal muscle. Researchers using screen-based simulations can study fewer subjects to reach valid conclusions that impact clinical care. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

International Nuclear Information System (INIS)

Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D'Ippolito, Giuseppe; Colleoni, Ramiro

2008-01-01

Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

Portal blood flow volume measurement in schistosomal patients: evaluation of Doppler ultrasonography reproducibility

Energy Technology Data Exchange (ETDEWEB)

Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; Shigueoka, David Carlos; D' Ippolito, Giuseppe [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Diagnostico por Imagem]. E-mail: ar.leao@uol.com.br; Colleoni, Ramiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Escola Paulista de Medicina. Dept. de Gastroenterologia

2008-09-15

Objective: To evaluate the reproducibility of Doppler ultrasonography in the measurement of portal blood flow volume in schistosomal patients. Materials and methods: Prospective, transversal, observational and self-paired study evaluating 21 patients with hepatosplenic schistosomiasis submitted to Doppler ultrasonography performed by three independent observers for measurement of portal blood flow. Pairwise interobserver agreement was calculated by means of the intraclass correlation coefficient, paired t-test and Pearson's correlation coefficient. Results: Interobserver agreement was excellent. Intraclass correlation ranged from 80.6% to 93.0% (IC at 95% [65.3% ; 95.8%]), with the Pearson's correlation coefficient ranging between 81.6% and 92.7% with no statistically significant interobserver difference regarding the mean portal blood flow volume measured by Doppler ultrasonography (p = 0.954 / 0.758 / 0.749). Conclusion: Doppler ultrasonography has demonstrated to be a reliable method for measuring the portal blood flow volume in patients with portal hypertension secondary to schistosomiasis, with a good interobserver agreement. (author)

Does hyperbaric oxygen treatment have the potential to increase salivary flow rate and reduce xerostomia in previously irradiated head and neck cancer patients? A pilot study

DEFF Research Database (Denmark)

Forner, Lone; Hansen, Ole Hyldegaard; von Brockdorff, Annet Schack

2011-01-01

in irradiated head and neck cancer patients. Eighty patients eligible for HBO treatment on the indication of prevention/treatment of osteoradionecrosis or soft tissue radiation injury were consecutively sampled, of whom 45 had hyposalivation (i.e. unstimulated whole saliva (UWS) flow rate......Irradiated head and neck cancer survivors treated in the Hyperbaric Oxygen (HBO) Unit, Copenhagen University Hospital, spontaneously reported improvement of radiation-induced dry mouth feeling. The aim of this pilot study was to evaluate salivary flow rate and xerostomia before and after HBO...

Salivary flow and its relationship to oral signs and symptoms in patients with dry eyes.

Science.gov (United States)

Koseki, M; Maki, Y; Matsukubo, T; Ohashi, Y; Tsubota, K

2004-03-01

The aim of this study was to investigate oral symptoms and clinical parameters in dry eye patients. Subjective reports of the sensation of a dry mouth, salivary flow rates, and clinical parameters of oral disease related to three different types of dry eye patients were examined. There were 224 individuals, including dry eye patients and control subjects. The dry eye patients were classified into three types: patients with Sjögren's syndrome (SS-DE), patients without SS-DE (non-SS-DE), and patients with Stevens-Johnson syndrome (SJS-DE). Salivary flow rates were measured using two kinds of sialometry. Subjective and objective oral symptoms and signs were also examined. Over half of the dry eye patients complained of a dry mouth. The flow rates of their stimulated whole saliva and parotid saliva were significantly lower than those of the control groups (P Candida frequently occurred in dry eye patients.

Characterization of cardiac flow in heart disease patients by computational fluid dynamics and 4D flow MRI

Science.gov (United States)

Lantz, Jonas; Gupta, Vikas; Henriksson, Lilian; Karlsson, Matts; Persson, Ander; Carhall, Carljohan; Ebbers, Tino

2017-11-01

In this study, cardiac blood flow was simulated using Computational Fluid Dynamics and compared to in vivo flow measurements by 4D Flow MRI. In total, nine patients with various heart diseases were studied. Geometry and heart wall motion for the simulations were obtained from clinical CT measurements, with 0.3x0.3x0.3 mm spatial resolution and 20 time frames covering one heartbeat. The CFD simulations included pulmonary veins, left atrium and ventricle, mitral and aortic valve, and ascending aorta. Mesh sizes were on the order of 6-16 million cells, depending on the size of the heart, in order to resolve both papillary muscles and trabeculae. The computed flow field agreed visually very well with 4D Flow MRI, with characteristic vortices and flow structures seen in both techniques. Regression analysis showed that peak flow rate as well as stroke volume had an excellent agreement for the two techniques. We demonstrated the feasibility, and more importantly, fidelity of cardiac flow simulations by comparing CFD results to in vivo measurements. Both qualitative and quantitative results agreed well with the 4D Flow MRI measurements. Also, the developed simulation methodology enables ``what if'' scenarios, such as optimization of valve replacement and other surgical procedures. Funded by the Wallenberg Foundation.

Analytical Tools to Improve Optimization Procedures for Lateral Flow Assays

Directory of Open Access Journals (Sweden)

Helen V. Hsieh

2017-05-01

Full Text Available Immunochromatographic or lateral flow assays (LFAs are inexpensive, easy to use, point-of-care medical diagnostic tests that are found in arenas ranging from a doctor’s office in Manhattan to a rural medical clinic in low resource settings. The simplicity in the LFA itself belies the complex task of optimization required to make the test sensitive, rapid and easy to use. Currently, the manufacturers develop LFAs by empirical optimization of material components (e.g., analytical membranes, conjugate pads and sample pads, biological reagents (e.g., antibodies, blocking reagents and buffers and the design of delivery geometry. In this paper, we will review conventional optimization and then focus on the latter and outline analytical tools, such as dynamic light scattering and optical biosensors, as well as methods, such as microfluidic flow design and mechanistic models. We are applying these tools to find non-obvious optima of lateral flow assays for improved sensitivity, specificity and manufacturing robustness.

Effect of breathing fluctuations on cerebral blood flow in demented patients and its correction method using end-tidal CO/sub 2/ concentration

Energy Technology Data Exchange (ETDEWEB)

Komatani, Akio; Yamaguchi, Koichi; Kera, Masahiro; Takanashi, Toshiyasu; Shinohara, Masao; Kawakatsu, Shinobu; Yazaki, Mitsuyasu

1989-02-01

During mouthpiece respiration of Xe-133 for a measurement of regional cerebral blood flow (rCBF), the breathing pattern of patients fluctuated and it caused a change of end-tidal CO/sub 2/ concentration that had an excellent correlation with PaCO/sub 2/ in patients without respiratory disease. The end-tidal CO/sub 2/ concentration of demented patients varied within lower ranges than senile control group. The range of fluctuation on the end-tidal CO/sub 2/ concentration was dependent on the type and the degree of dementia, and it fluctuated most widely at the middle stage of Alzheimer disease. Mean cerebral blood flow increased by 13.9% for each l% increase in end-tidal CO/sub 2/ concentration (3.6%/mmHg PaCO/sub 2/) in the case of demented patients without cerebrovascular disease. To improve the reliability of rCBF in demented patients, especially in Alzheimer disease, the correction of rCBF data for end-tidal CO/sub 2/ concentration should be performed.

Improved CFD Model to Predict Flow and Temperature Distributions in a Blast Furnace Hearth

Science.gov (United States)

Komiyama, Keisuke M.; Guo, Bao-Yu; Zughbi, Habib; Zulli, Paul; Yu, Ai-Bing

2014-10-01

The campaign life of a blast furnace is limited by the erosion of hearth refractories. Flow and temperature distributions of the liquid iron have a significant influence on the erosion mechanism. In this work, an improved three-dimensional computational fluid dynamics model is developed to simulate the flow and heat transfer phenomena in the hearth of BlueScope's Port Kembla No. 5 Blast Furnace. Model improvements feature more justified input parameters in turbulence modeling, buoyancy modeling, wall boundary conditions, material properties, and modeling of the solidification of iron. The model is validated by comparing the calculated temperatures with the thermocouple data available, where agreements are established within ±3 pct. The flow distribution in the hearth is discussed for intact and eroded hearth profiles, for sitting and floating coke bed states. It is shown that natural convection affects the flow in several ways: for example, the formation of (a) stagnant zones preventing hearth bottom from eroding or (b) the downward jetting of molten liquid promoting side wall erosion, or (c) at times, a vortex-like peripheral flow, promoting the "elephant foot" type erosion. A significant influence of coke bed permeability on the macroscopic flow pattern and the refractory temperature is observed.

Interface flow process audit: using the patient's career as a tracer of quality of care and of system organisation

Directory of Open Access Journals (Sweden)

Jean-Pierre Unger

2004-05-01

Full Text Available Objectives: This case study aims to demonstrate the method's feasibility and capacity to improve quality of care. Several drawbacks attached to tracer condition and selected procedure audits oblige clinicians to rely on external evaluators. Interface flow process audit is an alternative method, which also favours integration of health care across institutions divide. Methods: An action research study was carried out to test the feasibility of interface flow process audit and its impact on quality improvement. An anonymous questionnaire was carried out to assess the participants' perception of the process. Results: In this study, interface flow process audit brought together general practitioners and hospital doctors to analyse the co-ordination of their activities across the primary-secondary interface. Human factors and organisational characteristics had a clear influence on implementation of the solutions. In general, the participants confirmed that the interface flow process audit helped them to analyse the quality of case management both at primary and secondary care level. Conclusions: The interface flow process audit appears a useful method for regular in-service self-evaluation. Its practice enabled to address a wide scope of clinical, managerial and economical problems. Bridging the primary-secondary care gap, interface flow process audit's focus on the patient's career combined with the broad scope of problems that can be analysed are particularly powerful features. The methodology would benefit from an evaluation of its practice on larger scale.

Influence of ammonia flow rate for improving properties of polycrystalline GaN

Science.gov (United States)

Ariff, A.; Ahmad, M. A.; Hassan, Z.; Zainal, N.

2018-06-01

Post-annealing treatment in ammonia ambient is widely accepted for GaN material, but less works have been done to investigate the influence of the ammonia (NH3) flow rate for reducing the N-deficiency as well as improving the quality of the material. In this work, we investigated the influence of NH3 flow rate at 1, 2, 3, and 4 slm in improving properties of a ∼1 μm thick polycrystalline GaN layer. Our simulation work suggested that the uniformity of temperature and pressure gradient of the NH3 gas did not lead to the reduction of N-deficiency of the polycrystalline GaN layer. Instead, it was found that the mitigation of the N-deficiency was strongly influenced by the fluid velocity of the NH3 gas, which had passed over the layer. Either at lower or higher fluid velocity, the chance for the active N atoms to incorporate into the GaN lattice structure was low. Therefore, the N-deficiency on the polycrystalline GaN layer could not be minimized under these conditions. As measured by EDX, the N atoms incorporation was the most effective when the NH3 flow rate at 3 slm, suggesting the flow rate significantly improved the N-deficiency of the polycrystalline GaN layer. Furthermore, it favored the formation of larger hexagonal faceted grains, with the smallest FWHM of XRD peaks from the GaN diffractions in (10 1 bar 0), (0002) and (10 1 bar 1) orientations, while allowing the polycrystalline GaN layer to show sharp and intense emissions peak of NBE in a PL spectrum.

Efficiency improvements of electromagnetic flow control

International Nuclear Information System (INIS)

Spong, E.; Reizes, J.A.; Leonardi, E.

2005-01-01

In turbulent flow, frictional resistance and heat transfer are controlled to a large degree by the intensity of the turbulence fluctuations in the near vicinity of a surface. In the case of a weak electrically conducting fluid, such as seawater, turbulence intensity can be controlled by subjecting the fluid to electromagnetic fields. This technique, known as Electro-magneto-hydro-dynamic (EMHD) flow control, has been shown to have promise as a means of reducing the turbulence intensity, and hence heat transfer or frictional drag of turbulent boundary layers. Unfortunately EMHD flow control currently suffers from poor efficiency due to the high energy requirements of the electromagnetic field. A numerical study has been conducted in which a new electromagnetic actuator design has been developed to provide a more efficient spatial distribution of the electromagnetic forces. The new actuator design has then been coupled to an ideal flow sensor. A flow control subroutine, embedded in the numerical model, uses the velocity information from the ideal sensor to determine the appropriate actuating force to apply to the flow at each time step. The new actuator design has been shown to be capable of successfully attenuating a sequence of artificial low speed streaks in a simplified model of a low Reynolds number turbulent boundary layer. Thus, a potential solution to the poor efficiency of EMHD flow control has been offered by providing the means whereby the expensive electromagnetic forces can be strategically and sparingly applied to the flow

Integrating Flow, Form, and Function for Improved Environmental Water Management

Science.gov (United States)

Albin Lane, Belize Arela

Rivers are complex, dynamic natural systems. The performance of river ecosystem functions, such as habitat availability and sediment transport, depends on the interplay of hydrologic dynamics (flow) and geomorphic settings (form). However, most river restoration studies evaluate the role of either flow or form without regard for their dynamic interactions. Despite substantial recent interest in quantifying environmental water requirements to support integrated water management efforts, the absence of quantitative, transferable relationships between river flow, form, and ecosystem functions remains a major limitation. This research proposes a novel, process-driven methodology for evaluating river flow-form-function linkages in support of basin-scale environmental water management. This methodology utilizes publically available geospatial and time-series data and targeted field data collection to improve basic understanding of river systems with limited data and resource requirements. First, a hydrologic classification system is developed to characterize natural hydrologic variability across a highly altered, physio-climatically diverse landscape. Next, a statistical analysis is used to characterize reach-scale geomorphic variability and to investigate the utility of topographic variability attributes (TVAs, subreach-scale undulations in channel width and depth), alongside traditional reach-averaged attributes, for distinguishing dominant geomorphic forms and processes across a hydroscape. Finally, the interacting roles of flow (hydrologic regime, water year type, and hydrologic impairment) and form (channel morphology) are quantitatively evaluated with respect to ecosystem functions related to hydrogeomorphic processes, aquatic habitat, and riparian habitat. Synthetic river corridor generation is used to evaluate and isolate the role of distinct geomorphic attributes without the need for intensive topographic surveying. This three-part methodology was successfully

Regional cerebral blood flow and the effects of nicardipine, a new cerebral vasodilator, in patients with neuropsychiatric symptoms

International Nuclear Information System (INIS)

Toyoda, Katsuhiro; Motomura, Naoyasu; Murata, Koen; Sakai, Toshiaki; Yoshioka, Michio; Tsutsumi, Shigetoshi.

1984-01-01

Regional cerebral blood flow (rCBF) was determined by 133 Xe inhalation method in 22 neuropsychiatric patients with an average age of 65.8 years -- 14 patients having cerebrovascular disturbance (Group 1) and 8 patients having endogenous or organic psychosis or neurological lesions (Group 2). Furthermore, nicardipine was orally administered to the patients and its effects on rCBF and on neuropsychiatric symptoms were examined. Regarding the mean and abnormal decrease of rCBF in the bilateral hemispheres and the frequency of ischemic foci, there was no significant difference between the groups. However, regional ischemic focus was more frequently observed in Group 1 than in Group 2. Long-term serial administration of nicardipine increased the rCBF and improved psychiatric symptoms in some of the patients in Group 1. (Namekawa, K.)

Doppler Flow Wire Evaluation of Renal Blood Flow Reserve in Hypertensive Patients with Normal Renal Arteries

International Nuclear Information System (INIS)

Beregi, Jean-Paul; Mounier-Vehier, Claire; Devos, Patrick; Gautier, Corinne; Libersa, Christian; McFadden, Eugene P.; Carre, Alain

2000-01-01

Purpose: To study the vasomotor responses of the renal microcirculation in patients with essential hypertension.Methods: We studied the reactivity of the renal microcirculation to papaverine, with intraarterial Doppler and quantitative arteriography, in 34 renal arteries of 19 hypertensive patients without significant renal artery stenosis. Isosorbide dinitrate was given to maximally dilate proximal renal arteries. APV (average peak blood flow velocity) was used as an index of renal blood flow.Results: Kidneys could be divided into two distinct subgroups based on their response to papaverine. An increase in APV of up to 55% occurred in 21 kidneys, an increase > 55% in 13 kidneys. Within each group the values were normally distributed. Both baseline APV and the effect of papaverine on mean velocity differed significantly between groups.Conclusion: There seems to be a subgroup of patients with essential hypertension that has an impaired reactivity to papaverine, consistent with a functional impairment of the renal microcirculation. Further studies are required to determine whether this abnormality contributes to or results from elevated blood pressure

Measurement plans for process flow improvement in services and health care

NARCIS (Netherlands)

Kemper, B.; de Mast, J.

2013-01-01

The discussion of performance measurement is often on a conceptual, not operational, level; advice on the operational and practical matters of obtaining data for process flow improvement is scarce. We define a measurement plan and study four measurement study designs and corresponding methods and

Improvement of the characteristics of a diagonal-flow fan in low flow range with casing-bleed-holes; Keshingu kiko ni yoru sharyu sofuki no teiryu ryoiki tokusei no kaizen

Energy Technology Data Exchange (ETDEWEB)

Ando, Yoichi; Sasaki, Kazuto; Yamaguchi, Sumio; Yamashita, Shoji; Shimada, Taichiro

1999-09-01

Generally, a high specific speed diagonal flow fan with a small pressure rise coefficient has a slight positive gradient part of the pressure rise - flow rate characteristics. In addition, the pressure fall is small, between the flow rate at which the impeller stall in the throttle closer and the stalling flow rate. In the case, Kaneko et al. suggest a way of improvement on performance characteristics by an inlet annular wing which removes a low-momentum fluid from a rotor tip region. However, in case of a fan that has a sharp drop of pressure rise in the stall characteristics, it is not clear that the stall characteristics can be improved by this way. In this study, in order to improve the unstable characteristics of a high pressure rise coefficient diagonal flow fan, Tip clearance flow has been investigated on five rotor-casings with various holes to bleed low-momentum fluid in the range of flow rate from design point to stall point. (author)

A computational procedure to improve airfoil performance considering shape and flow interactions

International Nuclear Information System (INIS)

Darbandi, M.; Taghvaey, M.J.; Schneider, G.E.

2004-01-01

Despite remarkable progress in shape design issue, there is still room to work on this topic considering different flow field conditions and specific aerodynamic applications. Today, the optimization techniques are known as a major tool to reach the best possible aerodynamic shape for some specific conditions. In general direct optimization techniques, the optimization process is started from choosing a suitable primitive shape and the shape is improved by suitable considerations of the design objectives and constraints. In a similar attempt, we develop a new optimization strategy to improve the airfoil shape for specified applications. The strategy involves several stages. It includes to determine the flow conditions and design parameters, to establish the objective function, to select a suitable primitive shape, to generate a mechanism for inserting gradual shape changes, to generate grids around each defined shape, to solve the flow field for each separate shape, to collect the solution data, to change the discrete data to the continuous distribution functions, to construct the objective function, and to minimize the objective function using the steepest descent approach. No constraint function is incorporated into the constructed objective function. The cruise flight of an aircraft at an specified altitude is supposed to be the flow field conditions around the proposed airfoil. Nevertheless, the flow field is assumed to be viscous and compressible as well as turbulent. The procedure is tested starting from two generic airfoil shapes with and without camber. The developed algorithm works well for both cases; however, it may not converge to identical shapes if the primitive shapes are not identical. (author)

A computational procedure to improve airfoil performance considering shape and flow interactions

Energy Technology Data Exchange (ETDEWEB)

Darbandi, M.; Taghvaey, M.J. [Sharif Univ. of Technology, Dept. of Aerospace Engineering, Tehran (Iran, Islamic Republic of)]. E-mail: darbandi@sharif.edu; Schneider, G.E. [Univ. of Waterloo, Dept. of Mechanical Engineering, Waterloo, Ontario (Canada)

2004-07-01

Despite remarkable progress in shape design issue, there is still room to work on this topic considering different flow field conditions and specific aerodynamic applications. Today, the optimization techniques are known as a major tool to reach the best possible aerodynamic shape for some specific conditions. In general direct optimization techniques, the optimization process is started from choosing a suitable primitive shape and the shape is improved by suitable considerations of the design objectives and constraints. In a similar attempt, we develop a new optimization strategy to improve the airfoil shape for specified applications. The strategy involves several stages. It includes to determine the flow conditions and design parameters, to establish the objective function, to select a suitable primitive shape, to generate a mechanism for inserting gradual shape changes, to generate grids around each defined shape, to solve the flow field for each separate shape, to collect the solution data, to change the discrete data to the continuous distribution functions, to construct the objective function, and to minimize the objective function using the steepest descent approach. No constraint function is incorporated into the constructed objective function. The cruise flight of an aircraft at an specified altitude is supposed to be the flow field conditions around the proposed airfoil. Nevertheless, the flow field is assumed to be viscous and compressible as well as turbulent. The procedure is tested starting from two generic airfoil shapes with and without camber. The developed algorithm works well for both cases; however, it may not converge to identical shapes if the primitive shapes are not identical. (author)

Occult CSF flow disturbance of patients with Alzheimer type dementia and vascular dementia

International Nuclear Information System (INIS)

Kono, Kazuhiko; Sugita, Yasuko; Funaki, Chiaki

1994-01-01

We report results of Iotrolan CT-cisternography on 41 demented patients (13 males and 28 females) to find 'occult normal pressure hydrocephalus'. These patients were suspected to have CSF flow disturbance from clinical symptoms and simple brain CT scan findings. Their average age, duration of dementia, and score of Hasegawa's dementia scale (HDS) were 76.2 years, 5.9 years, 9.5/32.5,respectively. Before performing CT-cisternography, clinical diagnosis for their dementia were vascular dementia in 18 patients. Alzheimer type dementia in 12, suspect of NPH in 5, and other diagnoses in 6. From the results of cisternography, we found 13 patients with CSF flow disturbance (contrast material remained in the ventricle more than 48 hours after injection), and 17 patients with normal CSF flow. The former showed lower scores of HDS, higher urinary incontinence scores and smaller areas of the interhemispheric fissure on CT scan than the latter. But the former showed no significant difference from the latter in the average age, duration of dementia and width of the ventricles. (author)

Linking Six Sigma to simulation: a new roadmap to improve the quality of patient care.

Science.gov (United States)

Celano, Giovanni; Costa, Antonio; Fichera, Sergio; Tringali, Giuseppe

2012-01-01

Improving the quality of patient care is a challenge that calls for a multidisciplinary approach, embedding a broad spectrum of knowledge and involving healthcare professionals from diverse backgrounds. The purpose of this paper is to present an innovative approach that implements discrete-event simulation (DES) as a decision-supporting tool in the management of Six Sigma quality improvement projects. A roadmap is designed to assist quality practitioners and health care professionals in the design and successful implementation of simulation models within the define-measure-analyse-design-verify (DMADV) or define-measure-analyse-improve-control (DMAIC) Six Sigma procedures. A case regarding the reorganisation of the flow of emergency patients affected by vertigo symptoms was developed in a large town hospital as a preliminary test of the roadmap. The positive feedback from professionals carrying out the project looks promising and encourages further roadmap testing in other clinical settings. The roadmap is a structured procedure that people involved in quality improvement can implement to manage projects based on the analysis and comparison of alternative scenarios. The role of Six Sigma philosophy in improvement of the quality of healthcare services is recognised both by researchers and by quality practitioners; discrete-event simulation models are commonly used to improve the key performance measures of patient care delivery. The two approaches are seldom referenced and implemented together; however, they could be successfully integrated to carry out quality improvement programs. This paper proposes an innovative approach to bridge the gap and enrich the Six Sigma toolbox of quality improvement procedures with DES.

Architecture for improved mass transport and system performance in redox flow batteries

Science.gov (United States)

Houser, Jacob; Pezeshki, Alan; Clement, Jason T.; Aaron, Douglas; Mench, Matthew M.

2017-05-01

In this work, electrochemical performance and parasitic losses are combined in an overall system-level efficiency metric for a high performance, all-vanadium redox flow battery. It was found that pressure drop and parasitic pumping losses are relatively negligible for high performance cells, i.e., those capable of operating at a high current density while at a low flow rate. Through this finding, the Equal Path Length (EPL) flow field architecture was proposed and evaluated. This design has superior mass transport characteristics in comparison with the standard serpentine and interdigitated designs at the expense of increased pressure drop. An Aspect Ratio (AR) design is discussed and evaluated, which demonstrates decreased pressure drop compared to the EPL design, while maintaining similar electrochemical performance under most conditions. This AR design is capable of leading to improved system energy efficiency for flow batteries of all chemistries.

Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position.

Science.gov (United States)

Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

2016-01-01

The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pstate index values (T1-T4) showed no significant change; however, comparing only T1 and T2 resulted in a statically significant decrease in patient state index. There was a significant decrease in cerebral blood flow after beach chair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position].

Science.gov (United States)

Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

2016-01-01

The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pstate index values (T1-T4) showed no significant change; however, comparing only T1 and T2 resulted in a statically significant decrease in patient state index. There was a significant decrease in cerebral blood flow after beach chair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Significant Improvements in Pyranometer Nighttime Offsets Using High-Flow DC Ventilation

Energy Technology Data Exchange (ETDEWEB)

Kutchenreiter, Mark; Michalski, J.J.; Long, C.N.; Habte, Aron

2017-05-22

Accurate solar radiation measurements using pyranometers are required to understand radiative impacts on the Earth's energy budget, solar energy production, and to validate radiative transfer models. Ventilators of pyranometers, which are used to keep the domes clean and dry, also affect instrument thermal offset accuracy. This poster presents a high-level overview of the ventilators for single-black-detector pyranometers and black-and-white pyranometers. For single-black-detector pyranometers with ventilators, high-flow-rate (50-CFM and higher), 12-V DC fans lower the offsets, lower the scatter, and improve the predictability of nighttime offsets compared to lower-flow-rate (35-CFM), 120-V AC fans operated in the same type of environmental setup. Black-and-white pyranometers, which are used to measure diffuse horizontal irradiance, sometimes show minor improvement with DC fan ventilation, but their offsets are always small, usually no more than 1 W/m2, whether AC- or DC-ventilated.

High Flow Nasal Cannula Therapy for Improving Obstructive Sleep Apnea: A Case Report

Directory of Open Access Journals (Sweden)

Se Joong Kim

2015-06-01

Full Text Available Although continuous positive airway pressure is the treatment of choice for obstructive sleep apnea, its compliance is low. Therefore, alternative therapeutic strategies are often required. High flow nasal cannula therapy uses an air compressor to deliver a constant flow of oxygen via the nasal cannula at a maximum of 60 L/m. It can produce positive end expiratory pressure and increase end expiratory pharyngeal pressure, which can help to alleviate upper airway obstruction. This is a case report of high flow nasal cannula therapy for a 71 year-old man. He had an obstructive sleep apnea and severe desaturation but failed to use continuous positive airway pressure. He underwent titration with high flow nasal cannula under polysomnography. Using high flow nasal cannula at an airflow of 45 L/m, his apnea-hypopnea, respiratory arousal and oxygen desaturation were improved. Importantly, he is very compliant with high flow nasal cannula therapy.

Improved brachial artery shear patterns and increased flow-mediated dilation after low-volume high-intensity interval training in type 2 diabetes.

Science.gov (United States)

Ghardashi Afousi, Alireza; Izadi, Mohammad Reza; Rakhshan, Kamran; Mafi, Farnoosh; Biglari, Soheil; Gandomkar Bagheri, Habibalah

2018-06-22

What is the central question of this study? Endothelial function is impaired because of increased oscillatory and retrograde shear in patients with type 2 diabetes. It is unclear whether low-volume high-intensity interval training and continuous moderate intensity exercise can modulate oscillatory and retrograde shear, blood flow and flow-mediated arterial dilation in these patients. What is the main finding and its importance? We found that low-volume high-intensity interval training, by increasing anterograde shear and decreasing retrograde shear and oscillatory index, can increase nitric oxide production and consequently result in increased flow-mediated dilation and outward arterial remodelling in patients with type 2 diabetes. Atherosclerosis in patients with type 2 diabetes is characterized by endothelial dysfunction associated with impaired flow-mediated dilation (FMD) and increases retrograde and oscillatory shear. The present study investigated endothelium-dependent vasodilation and shear rate in patients with type 2 diabetes at baseline and follow-up after 12 weeks of low-volume high-intensity interval training (LV-HIIT) or continuous moderate intensity training (CMIT). Seventy five sedentary patients with type 2 diabetes and untreated pre- or stage I hypertension were randomly divided into LV-HIIT, CMIT and control groups. The LV-HIIT group intervention was 12 intervals of 1.5 min at 85%-90% HR max and 2 min at 55%-60% HR max . The CMIT group intervention was 42 min of exercise at 70% HR max for 3 sessions per week during 12 weeks. High-resolution Doppler ultrasound was used to measure FMD, arterial diameter, anterograde and retrograde blood flow and shear rate patterns. Brachial artery FMD increased significantly in the LV-HIIT group (3.83 ± 1.13 baseline, 7.39 ± 3.6% follow-up), whereas there were no significant increase in the CMIT group (3.45 ± 0.97 baseline, 4.81 ± 2.36% follow-up) compared to the control group (3.16 ± 0

Studies on the hepatic hemodynamics of the patients with fatty liver by hepatic blood flow mapping

International Nuclear Information System (INIS)

Kubo, Shuichi; Okajima, Tugio; Yamazaki, Yasurou

1991-01-01

To investigate intrahepatic hemodynamics of the patients with fatty liver, the time to reach maximal enhancement (PT) of every 3 x 3 pixel was depicted by a gray scale throughout an area of maximal horizontal slice of CT of the liver to obtain blood flow mapping of the liver, and compared with those of normal, chronic hepatitis and cirrhosis. Mottles of deep gray, light gray or black pixels were distributed throughout the liver slice of fatty liver. Although the mean PT of a ROI of fatty liver was longer than normal and shorter than that of cirrhosis and the same as that of chronic hepatitis, the map of fatty liver was different from that of chronic hepatitis. When the distribution of PT was expressed by their histogram, it was known that PT of fatty liver had a wider range than that of chronic hepatitis. The range was the same as that of cirrhosis. In one case of fatty liver, the deep gray pixels was increased when fatty infiltration of the liver was improved. It was concluded that the intrahepatic blood flow of fatty liver was impaired in a way not similar to chronic hepatitis or liver cirrhosis, which could be clearly seen by hepatic blood flow mapping, and which seemed to be reversible with the improvement of fatty liver. (author)

Salivary flow and corono-radicular caries in elderly patients

OpenAIRE

Campodónico Reategui, Carlos; Chein Villacampa, Sylvia; Benavente Lipa, Lourdes; Delgadillo Avila, Juana; Alvarez Paucar, Maria Angelica; Espinoza Escajadillo, Sofia; Vidal Goñi, Raúl; Ventocilla Huasupoma, Maria; Evaristo Chiyong, Teresa

2014-01-01

The aim of this study was to determine the correlation between hypo-salivation and corono-radicular caries in older adult patients, which analyzed the physicochemical properties of saliva (flow, pH), the frequency and location of the corono-radicular caries. Was selected a sample of 45 persons, adult patients over 60 years and another 18 to 26 years (control group), from service centers, hospitals and universities. The technique of collection of saliva, consisted of making chewing a piece of ...

Postoperative Reverse Remodeling and Symptomatic Improvement in Normal-Flow Low-Gradient Aortic Stenosis After Aortic Valve Replacement.

Science.gov (United States)

Carter-Storch, Rasmus; Møller, Jacob E; Christensen, Nicolaj L; Irmukhadenov, Akhmadjon; Rasmussen, Lars M; Pecini, Redi; Øvrehus, Kristian A; Søndergård, Eva V; Marcussen, Niels; Dahl, Jordi S

2017-12-01

Severe aortic stenosis (AS) most often presents with reduced aortic valve area (gradient (≥40 mm Hg; normal-flow high-gradient AS) or low mean gradient (normal-flow low-gradient [NFLG] AS). The benefit of aortic valve replacement (AVR) among NFLG patients is controversial. We compared the impact of NFLG condition on preoperative left ventricular (LV) remodeling and myocardial fibrosis and postoperative remodeling and symptomatic benefit. Eighty-seven consecutive patients with reduced aortic valve area and normal stroke volume index undergoing AVR underwent echocardiography, magnetic resonance imaging, a 6-minute walk test, and measurement of natriuretic peptides before and 1 year after AVR. Myocardial fibrosis was assessed from magnetic resonance imaging. Patients were stratified as NFLG or normal-flow high-gradient. In total, 33 patients (38%) had NFLG. Before AVR, they were characterized by similar symptom burden but less severe AS measured by aortic valve area index (0.50±0.09 versus 0.40±0.08 cm 2 /m 2 ; P gradient condition independently predicted change in LV mass index. Patients with NFLG had less severe AS and LV remodeling than patients with normal-flow high-gradient. Furthermore, NFLG patients experienced less reverse remodeling but the same symptomatic benefit. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02316587. © 2017 American Heart Association, Inc.

Cerebral blood flow and cerebrovascular response to acetazolamide in patients with chronic alcoholism

OpenAIRE

Oishi, M; Mochizuki, Y; Takasu, T

1997-01-01

Cerebral blood flow and cerebrovascular response to acetazolamide were studied in 12 patients with chronic alcoholism and 12 age matched healthy controls. Blood flows in the cerebral cortex, thalamus, and putamen were significantly lower in the chronic alcoholic group than in the healthy control group. The increase in blood flow caused by acetazolamide did not show any significant difference between the two groups. These findings suggest that the decreased cerebral blood flow i...

Improving patient safety culture in Saudi Arabia (2012-2015): trending, improvement and benchmarking.

Science.gov (United States)

Alswat, Khalid; Abdalla, Rawia Ahmad Mustafa; Titi, Maher Abdelraheim; Bakash, Maram; Mehmood, Faiza; Zubairi, Beena; Jamal, Diana; El-Jardali, Fadi

2017-08-02

Measuring patient safety culture can provide insight into areas for improvement and help monitor changes over time. This study details the findings of a re-assessment of patient safety culture in a multi-site Medical City in Riyadh, Kingdom of Saudi Arabia (KSA). Results were compared to an earlier assessment conducted in 2012 and benchmarked with regional and international studies. Such assessments can provide hospital leadership with insight on how their hospital is performing on patient safety culture composites as a result of quality improvement plans. This paper also explored the association between patient safety culture predictors and patient safety grade, perception of patient safety, frequency of events reported and number of events reported. We utilized a customized version of the patient safety culture survey developed by the Agency for Healthcare Research and Quality. The Medical City is a tertiary care teaching facility composed of two sites (total capacity of 904 beds). Data was analyzed using SPSS 24 at a significance level of 0.05. A t-Test was used to compare results from the 2012 survey to that conducted in 2015. Two adopted Generalized Estimating Equations in addition to two linear models were used to assess the association between composites and patient safety culture outcomes. Results were also benchmarked against similar initiatives in Lebanon, Palestine and USA. Areas of strength in 2015 included Teamwork within units, and Organizational Learning-Continuous Improvement; areas requiring improvement included Non-Punitive Response to Error, and Staffing. Comparing results to the 2012 survey revealed improvement on some areas but non-punitive response to error and Staffing remained the lowest scoring composites in 2015. Regression highlighted significant association between managerial support, organizational learning and feedback and improved survey outcomes. Comparison to international benchmarks revealed that the hospital is performing at or

Relationship between preoperative radial artery and postoperative arteriovenous fistula blood flow in hemodialysis patients.

Science.gov (United States)

Sato, Michiko; Io, Hiroaki; Tanimoto, Mitsuo; Shimizu, Yoshio; Fukui, Mitsumine; Hamada, Chieko; Horikoshi, Satoshi; Tomino, Yasuhiko

2012-01-01

It is recommended that arteriovenous fistula (AVF) blood flow should be more than 425 ml/min before cannulation. However, the relationship between preoperative radial artery flow (RAF) and postoperative AVF blood flow has still not been examined. Sixty-one patients with end-stage kidney disease (ESKD) were examined. They had an AVF prepared at Juntendo University Hospital from July 2006 through August 2007. Preoperative RAF and postoperative AVF blood flows were measured by ultrasonography. AVF blood flow gradually increased after the operation. AVF blood flow was significantly correlated with preoperative RAF. When preoperative RAF exceeded 21.4 ml/min, AVF blood flow rose to more than 425 ml/min. The postoperative AVF blood flow in the group with RAF of more than 20 ml/min was significantly higher than that in those with less than 20 ml/min. Preoperative RAF of less than 20 ml/min had a significantly high risk of primary AVF failure within 8 months compared with that of more than 20 ml/min. It appears that measurement of RAF by ultrasonography is useful for estimating AVF blood flow postoperatively and can predict the risk of complications in ESKD patients.

Improving Ambient Wind Environments of a Cross-flow Wind Turbine near a Structure by using an Inlet Guide Structure and a Flow Deflector

Institute of Scientific and Technical Information of China (English)

Tadakazu TANINO; Shinichiro NAKAO; Genki UEBAYASHI

2005-01-01

A cross-flow wind turbine near a structure was tested for the performance. The results showed that the performance of a cross-flow wind turbine near a structure was up to 30% higher than the one without a structure.In addition, we tried to get higher performance of a cross-flow wind turbine by using an Inlet Guide Structure and a Flow Deflector. An Inlet Guide Structure was placed on the edge of a structure and a Flow Deflector was set near a cross-flow wind turbine and can improve ambient wind environments of the wind turbine, the maximum power coefficients were about 15 to 40% higher and the tip speed ratio range showing the high power coefficient was wide and the positive gradients were steep apparently.

A comparison of dobutamine and levosimendan on hepatic blood flow in patients with a low cardiac output state after cardiac surgery: a randomised controlled study.

Science.gov (United States)

Alvarez, J; Baluja, A; Selas, S; Otero, P; Rial, M; Veiras, S; Caruezo, V; Taboada, M; Rodriguez, I; Castroagudin, J; Tome, S; Rodriguez, A; Rodriguez, J

2013-11-01

Liver dysfunction due to a low cardiac output state after cardiac surgery is associated with a poor prognosis, but whether one inotrope is superior to another in improving hepatic perfusion remains uncertain. This study compared the systemic and hepatic haemodynamic effects of levosimendan to dobutamine in patients with a low cardiac output state (cardiac index flow (ml/min): 614.0±124.7, 585.9±144.8; pulsatility index: 2.02±0,28, 2.98±0.27 versus the levosimendan group: cardiac index: 3.02± 0.27, 2.98± 0.30; portal vein flow: 723.0± 143.5, 702.9±117.8; pulsatility index: 1.71±0.26, 1.73±0.27). The improvement in portal vein blood flow at 48 hours was significantly better after levosimendan than dobutamine (41% vs. 11% increment from baseline, Pflow through both the hepatic artery and portal venous system, whereas dobutamine can only improve the portal venous blood flow without vasodilating the hepatic artery.

Patient Education May Improve Perioperative Safety.

NARCIS (Netherlands)

de Haan, L.S.; Calsbeek, H; Wolff, André

2016-01-01

Importance: There is a growing interest in enabling ways for patients to participate in their own care to improve perioperative safety, but little is known about the effectiveness of interventions enhancing an active patient role. Objective: To evaluate the effect of patient participation on

An Improved Ghost-cell Immersed Boundary Method for Compressible Inviscid Flow Simulations

KAUST Repository

Chi, Cheng

2015-01-01

This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary

Leukocyte and platelet depletion improves blood flow and function in a renal transplant model.

Science.gov (United States)

Yates, Phillip J; Hosgood, Sarah A; Nicholson, Michael L

2012-01-01

Donation after cardiac death (DCD) donors are an important source of organs for transplantation. Due to warm and cold ischemic injury, DCD kidneys undergo a significant reperfusion insult when transplanted. This is manifested clinically as a high incidence of delayed graft function (DGF) and primary non-function (PNF). The importance of leukocytes in the generation of reperfusion injury is pivotal. Using an ex vivo porcine model of kidney transplantation, the effects of reperfusion with leukocyte and platelet depleted blood (LDB) and whole blood (WB) on renal blood flow and function were compared. Hemodynamic measurements were recorded, and biochemical, hematological, and histologic samples taken at set time-points. Reperfusion with LDB improved renal blood flow significantly compared with WB reperfusion. In addition, there was a significant improvement in creatinine clearance and renal oxygen consumption, but not fractional excretion of sodium, acid-base homeostasis, urinary nitric oxide (NO), or 8-isoprostane levels. This study represents a good model for the initial reperfusion period in renal transplantation. Improvement in only some functional markers and neither urinary NO nor 8-isoprostane levels indicates that improved blood flow alone is not sufficient to reverse the severe ischemic insult endured by DCD kidneys. Copyright © 2012 Elsevier Inc. All rights reserved.

The feasibility of measuring renal blood flow using transesophageal echocardiography in patients undergoing cardiac surgery.

Science.gov (United States)

Yang, Ping-Liang; Wong, David T; Dai, Shuang-Bo; Song, Hai-Bo; Ye, Ling; Liu, Jin; Liu, Bin

2009-05-01

There is no reliable method to monitor renal blood flow intraoperatively. In this study, we evaluated the feasibility and reproducibility of left renal blood flow measurements using transesophageal echocardiography during cardiac surgery. In this prospective noninterventional study, left renal blood flow was measured with transesophageal echocardiography during three time points (pre-, intra-, and postcardiopulmonary bypass) in 60 patients undergoing cardiac surgery. Sonograms from 6 subjects were interpreted by 2 blinded independent assessors at the time of acquisition and 6 mo later. Interobserver and intraobserver reproducibility were quantified by calculating variability and intraclass correlation coefficients. Patients with Doppler angles of >30 degrees (20 of 60 subjects) were eliminated from renal blood flow measurements. Left renal blood flow was successfully measured and analyzed in 36 of 60 (60%) subjects. Both interobserver and intraobserver variability were renal blood flow measurements were good to excellent (intraclass correlation coefficients 0.604-0.999). Left renal arterial luminal diameter for the pre, intra, and postcardiopulmonary bypass phases, ranged from 3.8 to 4.1 mm, renal arterial velocity from 25 to 35 cm/s, and left renal blood flow from 192 to 299 mL/min. In patients undergoing cardiac surgery, it was feasible in 60% of the subjects to measure left renal blood flow using intraoperative transesophageal echocardiography. The interobserver and intraobserver reproducibility of renal blood flow measurements was good to excellent.

Improved Performance of Personalized Ventilation by Control of the Convection Flow around Occupant Body

DEFF Research Database (Denmark)

Bolashikov, Zhecho Dimitrov; Melikov, Arsen Krikor; Krenek, Miroslav

2009-01-01

This paper reports on methods of control of the free convection flow around human body aiming at improvement of inhaled air quality for occupants at workstations with personalized ventilation (PV). Two methods of control were developed and explored: passive - blocking the free convection developm......This paper reports on methods of control of the free convection flow around human body aiming at improvement of inhaled air quality for occupants at workstations with personalized ventilation (PV). Two methods of control were developed and explored: passive - blocking the free convection......-scale test room with background mixing ventilation. Thermal manikin with realistic free convection flow was used. The PV supplied air from front/above towards the face. All measurements were performed under isothermal conditions at 20 °C and 26 °C. The air in the test room was mixed with tracer gas, while...

Improved crystalline quality of AlN epitaxial layer on sapphire by introducing TMGa pulse flow into the nucleation stage

Science.gov (United States)

Wu, Hualong; Wang, Hailong; Chen, Yingda; Zhang, Lingxia; Chen, Zimin; Wu, Zhisheng; Wang, Gang; Jiang, Hao

2018-05-01

The crystalline quality of AlN epitaxial layers on sapphire substrates was improved by introducing trimethylgallium (TMGa) pulse flow into the growth of AlN nucleation layers. It was found that the density of both screw- and edge-type threading dislocations could be significantly reduced by introducing the TMGa pulse flow. With increasing TMGa pulse flow times, the lateral correlation length (i.e. the grain size) increases and the strain in the AlN epilayers changes from tensile state to compressive state. Unstrained AlN with the least dislocations and a smooth surface was obtained by introducing 2-times TMGa pulse flow. The crystalline improvement is attributed to enhanced lateral growth and improved crystalline orientation by the TMGa pulse flow.

Performance improvement of a cross-flow hydro turbine by air layer effect

International Nuclear Information System (INIS)

Choi, Y D; Yoon, H Y; Inagaki, M; Ooike, S; Kim, Y J; Lee, Y H

2010-01-01

The purpose of this study is not only to investigate the effects of air layer in the turbine chamber on the performance and internal flow of the cross-flow turbine, but also to suggest a newly developed air supply method. Field test is performed in order to measure the output power of the turbine by a new air supply method. CFD analysis on the performance and internal flow of the turbine is conducted by an unsteady state calculation using a two-phase flow model in order to embody the air layer effect on the turbine performance effectively.The result shows that air layer effect on the performance of the turbine is considerable. The air layer located in the turbine runner passage plays the role of preventing a shock loss at the runner axis and suppressing a recirculation flow in the runner. The location of air suction hole on the chamber wall is very important factor for the performance improvement. Moreover, the ratio between air from suction pipe and water from turbine inlet is also significant factor of the turbine performance.

Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block

International Nuclear Information System (INIS)

Falcao, Andrea; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares Junior, Jose; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto; Meneghetti, Jose C.

2015-01-01

Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. Objective: we sought to investigate rubidium-82 ( 82 Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Methods: thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress 82 Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal 82 Rb-positron emission tomography studies and without left bundle branch block (GII). Results: stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p>0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). Conclusion: the data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by 82 Rb-positron emission tomography imaging may be useful in identifying coronary artery disease in patients

Renal transplantant blood flow in patients with acute tubular necrosis

Energy Technology Data Exchange (ETDEWEB)

Huic, D; Crnkovic, S; Bubic-Filipi, L J; Grosev, D; Dodig, P; Porapat, M; Puretic, Z [Univ. Hospital Rebro, Zagreb (Croatia)

1997-09-01

The aim of this study was to investigate the quantity of renal transport blood flow in patients affected by acute tubular necrosis (ATN). During the four years period two hundred and thirty-three studies were performed using {sup 99m}Tc pertechnetate and {sup 131}I - OIH. Renal blood flow was calculated from the first-pass time activity curves generated over the kidney and aorta and expressed as a percentage of cardiac output (RBF/CO). Renal transplant blood flow is clearly diminished in ATN, similar as in acute rejection, and significantly related to the graft function, what means that RBF/CO value could potentially serve as a prognostic factor in the graft function recovery from ATN.

Remote ischemic conditioning improves coronary microcirculation in healthy subjects and patients with heart failure

Directory of Open Access Journals (Sweden)

Kono Y

2014-08-01

Full Text Available Yasushi Kono,1 Shota Fukuda,1 Akihisa Hanatani,2 Koki Nakanishi,2 Kenichiro Otsuka,2 Haruyuki Taguchi,1 Kenei Shimada2 1Department of Medicine, Osaka Ekisaikai Hospital, Osaka, Japan; 2Department of Internal Medicine and Cardiology, Osaka City University School of Medicine, Osaka, Japan Background: Remote ischemic conditioning (RIC is a treatment modality that suppresses inflammation and improves endothelial function, which are factors involved in the pathogenesis of heart failure (HF with reduced left ventricular ejection fraction. Coronary flow reserve (CFR is a physiological index of coronary microcirculation and is noninvasively measured by transthoracic Doppler echocardiography (TTDE. This study aimed to investigate the effects of RIC on CFR in healthy subjects and patients with HF, through the assessment by TTDE. Methods: Ten patients with HF with left ventricular ejection fraction of less than 40%, and ten healthy volunteers were enrolled in this study. RIC treatment was performed twice a day for 1 week. Our custom-made RIC device was programmed to automatically conduct 4 cycles of 5 minutes inflation and 5 minutes deflation of a blood pressure cuff to create intermittent arm ischemia. CFR measurements and laboratory tests were examined before, and after 1 week of RIC treatment. Results: One week of RIC treatment was well tolerated in both groups. RIC treatment increased CFR from 4.0±0.9 to 4.6±1.3 (mean ± standard deviation in healthy subjects (P=0.02, and from 1.9±0.4 to 2.3±0.7 in patients with HF (P=0.03, respectively. Systolic blood pressure in healthy subjects, and heart rate in HF patients decreased after RIC treatment (both P<0.01. Conclusion: This study demonstrated that a 1 week course of RIC treatment improved coronary microcirculation in healthy subjects and patients with HF associated with reduced left ventricular ejection fraction. Keyword: echocardiography, coronary flow reserve, heart failure, preconditioning

Blood flow in the forearm in patients with Rheumatoid arthritis and healthy subjects under local thermotherapy

Directory of Open Access Journals (Sweden)

C. Mucha

2002-02-01

Full Text Available Objectives: Muscle blood flow in the forearm of patients with rheuma-toid arthritis and healthy volunteers following treatment with temperature increasingarm baths, mudpacks and short- or decimeter-wave diathermy was studied in thisinvestigation. The aim of the study was to find out the difference of reactive hyperemia between the different temperature methods as well as the influence on theconsensual reaction. Subjects: Eighty patients with rheumatoid arthritis, stage 3 according toSteinbrocker, as well as 80 healthy human subjects had been assigned numerically in the four therapy- and controlgroups. Patients with diseases influencing the peripheral blood flow were excluded. Design: Blood flow was measured by venous occlusion plethysmography in both forearms with the subjects lyingsupine. The application of the local heat therapies had been excluded on the left forearm. The forearm blood flow wasmonitored before heat therapy, directly after as well as in two further 10 minutes intervals. An analysis of variancewas used to determine the influence on blood flow of the response to the heat therapies in patients with rheumatoidarthritis and healthy subjects.Results: Under homogeneous starting conditions and a statistically uniformed high blood flow in rest the reactive values of blood flow on the left-hand side of application and the right consensual side showed high significant differencesbetween all methods of therapy. Differences between the patients and the healthy subjects only showed tendencies withpartially lower reactions, concerning the patients with rheumatoid arthritis. All methods of heat therapy caused a statistically provable consensual reaction that turned out smaller after diathermic methods. Here the post therapeuticreaction of the blood flow on the side of application was also lower or rather shorter. Conclusion: Greater differences of the blood flow in rest between the patients with rheumatoid arthritis and healthysubjects

Flow stagnation volume and abdominal aortic aneurysm growth: Insights from patient-specific computational flow dynamics of Lagrangian-coherent structures.

Science.gov (United States)

Joly, Florian; Soulez, Gilles; Garcia, Damien; Lessard, Simon; Kauffmann, Claude

2018-01-01

Abdominal aortic aneurysms (AAA) are localized, commonly-occurring dilations of the aorta. When equilibrium between blood pressure (loading) and wall mechanical resistance is lost, rupture ensues, and patient death follows, if not treated immediately. Experimental and numerical analyses of flow patterns in arteries show direct correlations between wall shear stress and wall mechano-adaptation with the development of zones prone to thrombus formation. For further insights into AAA flow topology/growth interaction, a workout of patient-specific computational flow dynamics (CFD) is proposed to compute finite-time Lyapunov exponents and extract Lagrangian-coherent structures (LCS). This computational model was first compared with 4-D phase-contrast magnetic resonance imaging (MRI) in 5 patients. To better understand the impact of flow topology and transport on AAA growth, hyperbolic, repelling LCS were computed in 1 patient during 8-year follow-up, including 9 volumetric morphologic AAA measures by computed tomography-angiography (CTA). LCS defined barriers to Lagrangian jet cores entering AAA. Domains enclosed between LCS and the aortic wall were considered to be stagnation zones. Their evolution was studied during AAA growth. Good correlation - 2-D cross-correlation coefficients of 0.65, 0.86 and 0.082 (min, max, SD) - was obtained between numerical simulations and 4-D MRI acquisitions in 6 specific cross-sections from 4 patients. In follow-up study, LCS divided AAA lumens into 3 dynamically-isolated zones: 2 stagnation volumes lying in dilated portions of the AAA, and circulating volume connecting the inlet to the outlet. The volume of each zone was tracked over time. Although circulating volume remained unchanged during 8-year follow-up, the AAA lumen and main stagnation zones grew significantly (8 cm 3 /year and 6 cm 3 /year, respectively). This study reveals that transient transport topology can be quantified in patient-specific AAA during disease progression

Measurement of vascular flow in the brain with the xenon/CT method

International Nuclear Information System (INIS)

Wist, A.O.; Cothran, A.; Fatouros, P.P.; Kishore, P.R.S.

1988-01-01

The authors are proposing a modification of the xenon/CT method that allows measurement of the flow in the different brain vessels. Based on an improved stable xenon/CT method, they developed several additional algorithms to differentiate the vessel flow from tissue flow and from artifacts and noise, which are based on the height, steepness, and other parameters of the detected flow values. The vessel flow maps, together with the tissue flow maps and new composite flow maps of recent patients, demonstrate that the stable xenon/CT technique can be extended to quantify vascular flow in the brain. The diagnostic capability of this method can be further improved by removing the vessel flow from the flow maps

Regional cerebral blood flow in the patient with brain tumor

International Nuclear Information System (INIS)

Tsuchida, Shohei

1993-01-01

Regional cerebral blood flow (rCBF) was measured with xenon-enhanced CT (Xe-CT) in 21 cases of intracranial tumors (13 meningiomas, 5 gliomas, 3 metastatic brain tumors). Peritumoral edema was graded as mild, moderate or severe based on the extent of edema on CT and MRI. According to intratumoral blood flow distribution patterns, three patterns were classified as central type with relatively high blood flow at the center of the tumor, homogeneous type with an almost homogeneous blood flow distribution, and marginal type with relatively high blood flow at the periphery of the tumor. High grade astrocytoma and metastatic brain tumor showed marginal type blood flow and moderate or severe edema except in one case. Five meningiomas with severe peritumoral edema revealed marginal type blood flow and four with mild peritumoral edema showed central type blood flow, except for one case. No correlation was found between the extent of peritumoral edema and histological subtype, tumor size, location, duration of clinical history, vascularization on angiogram, and mean blood flow in the tumor. These results suggest that blood flow distribution patterns within the tumor may affect the extension of peritumoral edema. Pre- and postoperative rCBFs were evaluated with Xe-CT and IMP-SPECT in 7 cases, mean rCBF of peritumoral edema was 6.2 ml/100 g/min preoperatively, and discrepancy between rCBF on Xe-CT and that on IMP-SPECT was shown in the remote cortical region ipsilateral to the tumor. Postoperative rCBF revealed an improved blood flow in both adjacent and remote areas, suggesting that the decreased blood flow associated with brain tumors might be relieved after surgery. (author) 53 refs

Regional cerebral blood flow during mechanical hyperventilation in patients with acute bacterial meningitis

DEFF Research Database (Denmark)

Møller, Kirsten; Høgh, Peter; Larsen, Fin Stolze

2000-01-01

Mechanical hyperventilation is often instituted in patients with acute bacterial meningitis when increased intracranial pressure is suspected. However, the effect on regional cerebral blood flow (CBF) is unknown. In this study, we measured regional CBF (rCBF) in patients with acute bacterial...... meningitis before and during short-term hyperventilation. In 17 patients with acute bacterial meningitis, absolute rCBF (in ml/100 g min-1) was measured during baseline ventilation and hyperventilation by single-photon emission computed tomography (SPECT) using intravenous 133Xe bolus injection. Intravenous...... in the frontal and parietal cortex as well as in the basal ganglia. Focal perfusion abnormalities were present in 10 of 12 patients. Regional cerebral blood flow abnormalities are frequent in patients with acute bacterial meningitis. Short-term hyperventilation does not enhance these abnormalities....

Characterization of esophageal pressure-flow abnormalities in patients with non-obstructive dysphagia and normal manometry findings.

Science.gov (United States)

Chen, Chien-Lin; Yi, Chih-Hsun; Liu, Tso-Tsai; Hsu, Ching-Sheng; Omari, Taher I

2013-06-01

Patients with non-obstructive dysphagia (NOD) report symptoms of impaired esophageal bolus transit without evidence of bolus stasis. In such patients, manometric investigation may diagnose esophageal motility disorders; however, many have normal motor patterns. We hypothesized that patients with NOD would demonstrate evidence of high flow-resistance during bolus passage which in turn would relate to the reporting of bolus hold up perception. Esophageal pressure-impedance recordings of 5 mL liquid and viscous swallows from 18 NOD patients (11 male; 19-71 years) and 17 control subjects (9 male; 25-60 years) were analyzed. The relationship between intrabolus pressure and bolus flow timing in the esophagus was assessed using the pressure flow index (PFI). Bolus perception was assessed swallow by swallow using standardized descriptors. NOD patients were characterized by a higher PFI than controls. The PFI defined a pressure-flow abnormality in all patients who appeared normal based on the assessment esophageal motor patterns and bolus clearance. The PFI was higher for individual swallows during which subjects reported perception of bolus passage. Bolus flow-resistance is higher in NOD patients compared with controls as well as higher in relation to perception of bolus transit, suggesting the presence of an esophageal motility disorder despite normal findings on conventional analysis. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Improving patient handover between teams using a business improvement model: PDSA cycle.

Science.gov (United States)

Luther, Vishal; Hammersley, Daniel; Chekairi, Ahmed

2014-01-01

Medical admission units are continuously under pressure to move patients off the unit to outlying medical wards and allow for new admissions. In a typical district general hospital, doctors working in these medical wards reported that, on average, three patients each week arrived from the medical admission unit before any handover was received, and a further two patients arrived without any handover at all. A quality improvement project was therefore conducted using a 'Plan, Do, Study, Act' cycle model for improvement to address this issue. P - Plan: as there was no framework to support doctors with handover, a series of standard handover procedures were designed. D - Do: the procedures were disseminated to all staff, and championed by key stakeholders, including the clinical director and matron of the medical admission unit. S - STUDY: Measurements were repeated 3 months later and showed no change in the primary end points. A - ACT: The post take ward round sheet was redesigned, creating a checkbox for a medical admission unit doctor to document that handover had occurred. Nursing staff were prohibited from moving the patient off the ward until this had been completed. This later evolved into a separate handover sheet. Six months later, a repeat study revealed that only one patient each week was arriving before or without a verbal handover. Using a 'Plan, Do, Study, Act' business improvement tool helped to improve patient care.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

Science.gov (United States)

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Berenstein, Laura Diaz; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2016-01-01

Objective Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. Methods 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3–9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. Results A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=−0.67–−0.70 for all patients on room air, p<0.01 and R=−0.49–−0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. Conclusions There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. Trial Registration Number NCT02135081. PMID:26048877

[Saw palmetto fruit extract improves LUTS in type ⅢA prostatitis patients].

Science.gov (United States)

Shao, Yun-Peng; Xue, Hao-Liang; Shen, Bai-Xin; Ding, Liu-Cheng; Chen, Zheng-Seng; Wei, Zhong-Qing

2017-05-01

To assess the clinical efficacy of the saw palmetto fruit extract (SPFE) in the treatment of lower urinary tract symptoms (LUTS) in patients with type ⅢA prostatitis. This retrospective study included 54 cases of type ⅢA prostatitis treated in the Outpatient Department of our hospital from January to December 2015. The patients were aged 35.06 ± 5.85 years, with a mean disease course of 3.8 ± 2.1 years, and all received oral medication of SPFE Capsules at the dose of 320 mg qd for 12 weeks. We assessed the therapeutic effects by comparing the NIH-chronic prostatitis symptom indexes (NIH-CPSI), voiding diary, International Prostate Symptom Scores (IPSS), and results of urodynamic examination before and after treatment. Compared with the baseline, both NIH-CPSI and IPSS were significantly decreased after medication (27.61 ± 3.76 vs 18.6 ± 5.34, P <0.01; 20.44 ± 4.51 vs 10.96±4.62, P <0.01), and urodynamic examination and voiding diary showed dramatic post-medication improvement in the average urinary flow rate (［8.05±1.42］ vs ［12.05±2.60］ ml/s, P <0.01 ), maximum urinary flow rate (［14.22±1.74］ vs ［21.32±4.51］ ml/s, P <0.01), residual urine volume (［46.15±16.57］ vs ［14.55±10.21］ ml, P <0.01), maximum urethral closure pressure (［76.52±3.53］ vs ［65.32±4.75］ cm H2O, P <0.01), mean urinary volume (［124.63±40.55］ vs ［285.93±58.68］ ml, P <0.01), urination frequency (16.96±4.17 vs 8.96±2.50, P <0.01), and nocturia frequency (8.94±3.23 vs 3.15±1.90, P <0.01). No apparent adverse reactions were observed in any of the patients. SPFE Capsules can safely and effectively improve LUTS and thus the quality of life of patients with type ⅢA prostatitis.

Effects of Bacillus subtilis var. natto products on symptoms caused by blood flow disturbance in female patients with lifestyle diseases

Science.gov (United States)

Hitosugi, Masahito; Hamada, Katsuo; Misaka, Kazutaka

2015-01-01

The fermented soybean product natto is a popular traditional food in Japan and is considered a health supplement. NKCP®, a natto-derived dietary food supplement whose main component is bacillopeptidase F, has antithrombotic, fibrinolytic, and blood pressure-lowering effects. We examined whether daily intake of NKCP® effectively improves subjective symptoms in patients with lifestyle diseases in this cross-over, double-blind study. Fermented soya extract with subtilisin NAT (nattokinase) as the main component was used as an active placebo. A 4-week course of NKCP® significantly decreased the visual analog scale (VAS) score for shoulder stiffness from 42.3 to 32.4 (P=0.009), the VAS score for low back pain from 25.5 to 18.8 (P=0.02), and the VAS score for coldness of the extremities from 33.1 to 25.7 (P=0.002). However, no significant difference was found in the VAS score for headache. After a 4-week course of active placebo, no significant changes in the VAS score were found for any symptoms. The significant improvement in the symptoms secondary to blood flow disturbance was caused by the improvement in blood flow by NKCP®. The use of dietary supplements based on the Japanese traditional food natto helps to relieve subjective symptoms for patients with lifestyle diseases receiving medical care. PMID:25653551

Glaucoma patients demonstrate faulty autoregulation of ocular blood flow during posture change

Science.gov (United States)

Evans, D.; Harris, A.; Garrett, M.; Chung, H. S.; Kagemann, L.

1999-01-01

BACKGROUND/AIMS—Autoregulation of blood flow during posture change is important to ensure consistent organ circulation. The purpose of this study was to compare the change in retrobulbar ocular blood flow in glaucoma patients with normal subjects during supine and upright posture.
METHODS—20 open angle glaucoma patients and 20 normal subjects, similar in age and sex distribution, were evaluated. Blood pressure, intraocular pressure, and retrobulbar blood velocity were tested after 30 minutes of sitting and again after 30 minutes of lying. Retrobulbar haemodynamic measures of peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were obtained in the ophthalmic and central retinal arteries using colour Doppler imaging (CDI).
RESULTS—When changing from the upright to supine posture, normal subjects demonstrated a significant increase in OA EDV (p = 0.016) and significant decrease in OA RI (p = 0.0006) and CRA RI (p = 0.016). Glaucoma patients demonstrated similar changes in OA measures of EDV (p = 0.02) and RI (p = 0.04), but no change in CRA measures.
CONCLUSION—Glaucoma patients exhibit faulty autoregulation of central retinal artery blood flow during posture change.

 PMID:10381668

Advanced porous electrodes with flow channels for vanadium redox flow battery

Science.gov (United States)

Bhattarai, Arjun; Wai, Nyunt; Schweiss, Ruediger; Whitehead, Adam; Lim, Tuti M.; Hng, Huey Hoon

2017-02-01

Improving the overall energy efficiency by reducing pumping power and improving flow distribution of electrolyte, is a major challenge for developers of flow batteries. The use of suitable channels can improve flow distribution through the electrodes and reduce flow resistance, hence reducing the energy consumption of the pumps. Although several studies of vanadium redox flow battery have proposed the use of bipolar plates with flow channels, similar to fuel cell designs, this paper presents the use of flow channels in the porous electrode as an alternative approach. Four types of electrodes with channels: rectangular open channel, interdigitated open cut channel, interdigitated circular poked channel and cross poked circular channels, are studied and compared with a conventional electrode without channels. Our study shows that interdigitated open channels can improve the overall energy efficiency up to 2.7% due to improvement in flow distribution and pump power reduction while interdigitated poked channel can improve up to 2.5% due to improvement in flow distribution.

Fractional flow reserve versus angiography for guiding percutaneous coronary intervention

DEFF Research Database (Denmark)

Tonino, Pim A L; De Bruyne, Bernard; Pijls, Nico H J

2009-01-01

of maximal blood flow in a stenotic artery to normal maximal flow), in addition to angiography, improves outcomes. METHODS: In 20 medical centers in the United States and Europe, we randomly assigned 1005 patients with multivessel coronary artery disease to undergo PCI with implantation of drug......BACKGROUND: In patients with multivessel coronary artery disease who are undergoing percutaneous coronary intervention (PCI), coronary angiography is the standard method for guiding the placement of the stent. It is unclear whether routine measurement of fractional flow reserve (FFR; the ratio...

Hemichorea in a diabetes mellitus patient following acute ischemic stroke with changes in regional cerebral blood flow

Directory of Open Access Journals (Sweden)

Yutaka Suzuki

2015-03-01

Full Text Available It is not unusual to observe hemichorea in patients with diabetes mellitus, with origins attributable to recent ischemia. Our patient was a 66-year-old female with diabetes mellitus who suddenly developed right hemichorea, mild muscle weakness of the right upper extremity, ideational apraxia, and acalculia. Her blood glucose was 600 mg/dL, and HbA1c was 13.3%. After the patient underwent head magnetic resonance imaging (MRI, a new cerebral infarction was observed in the left frontal lobe, and treatment was started with edaravone and cilostazol. At the same time, insulin treatment was also started for hyperglycemia. The acalculia and ideational apraxia improved approximately 1 week after treatment initiated, and the hemichorea also decreased. ECD-SPECT was performed on admission, and it was observed that blood flow was decreased in the left frontal lobe and striatum, but increased in the thalamus; two weeks later on follow-up ECD-SPECT, blood flow had increased slightly in the left forebrain and striatum, while it had decreased slightly in the thalamus. This suggests that the cause of hemichorea was related to ischemia. When the activity of the pallidum is impaired, it is presumed that the inhibitory activity towards the thalamus weakens and the thalamic cells become over-excited, causing chorea.

Pilot Study of Flow and Meaningfulness as Psychological Learning Concepts in Patient Education: A Short Report

DEFF Research Database (Denmark)

Nicic, Sara; Nørby, Karina; Bruun Johansen, Clea

2014-01-01

of this study was to investigate the applicability of these concepts of positive psychological theory in a patient education setting. Methods: This pilot study combines participating observation of group based patient education and 8 qualitative interviews with 4 patients with type 2 diabetes. Meaning......Abstract Background: The aim of this pilot study was to explore patient experiences of meaningfulness and flow related to group based patient education in type 2 diabetes. Meaningfulness and flow are underexposed as psychological learning concepts in patient education, and the ambition...

Cross-flow turbines: physical and numerical model studies towards improved array simulations

Science.gov (United States)

Wosnik, M.; Bachant, P.

2015-12-01

Cross-flow, or vertical-axis turbines, show potential in marine hydrokinetic (MHK) and wind energy applications. As turbine designs mature, the research focus is shifting from individual devices towards improving turbine array layouts for maximizing overall power output, i.e., minimizing wake interference for axial-flow turbines, or taking advantage of constructive wake interaction for cross-flow turbines. Numerical simulations are generally better suited to explore the turbine array design parameter space, as physical model studies of large arrays at large model scale would be expensive. However, since the computing power available today is not sufficient to conduct simulations of the flow in and around large arrays of turbines with fully resolved turbine geometries, the turbines' interaction with the energy resource needs to be parameterized, or modeled. Most models in use today, e.g. actuator disk, are not able to predict the unique wake structure generated by cross-flow turbines. Experiments were carried out using a high-resolution turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier--Stokes models. The ALM predicts turbine loading with the blade element method combined with sub-models for dynamic stall and flow curvature. The open-source software is written as an extension library for the OpenFOAM CFD package, which allows the ALM body force to be applied to their standard RANS and LES solvers. Turbine forcing is also applied to volume of fluid (VOF) models, e.g., for predicting free surface effects on submerged MHK devices. An

Ocular Perfusion Pressure and Pulsatile Ocular Blood Flow in Normal and Systemic Hypertensive Patients.

Science.gov (United States)

Kanadani, Fabio N; Figueiredo, Carlos R; Miranda, Rafaela Morais; Cunha, Patricia Lt; M Kanadani, Tereza Cristina; Dorairaj, Syril

2015-01-01

Glaucomatous neuropathy can be a consequence of insufficient blood supply, increase in intraocular pressure (IOP), or other risk factors that diminish the ocular blood flow. To determine the ocular perfusion pressure (OPP) in normal and systemic hypertensive patients. One hundred and twenty-one patients were enrolled in this prospective and comparative study and underwent a complete ophthalmologic examination including slit lamp examination, Goldmann applanation tonometry, stereoscopic fundus examination, and pulsatile ocular blood flow (POBF) measurements. The OPP was calculated as being the medium systemic arterial pressure (MAP) less the IOP. Only right eye values were considered for calculations using Student's t-test. The mean age of the patients was 57.5 years (36-78), and 68.5% were women. There was a statistically significant difference in the OPP of the normal and systemic hypertensive patients (p cite this article: Kanadani FN, Figueiredo CR, Miranda RM, Cunha PLT, Kanadani TCM, Dorairaj S. Ocular Perfusion Pressure and Pulsatile Ocular Blood Flow in Normal and Systemic Hypertensive Patients. J Curr Glaucoma Pract 2015;9(1):16-19.

Improving patient-centredness in partnership with female patients: a cluster RCT in fertility care

NARCIS (Netherlands)

Huppelschoten, A.G.; Nelen, W.L.D.M.; Westert, G.P.; Golde, R.J.T. van; Adang, E.M.M.; Kremer, J.A.M.

2015-01-01

QUESTION: What is the effect of a multifaceted intervention with participation of patients on improvement of patient-centredness in fertility care? SUMMARY ANSWER: A multifaceted intervention with participation of patients did not improve total patient-centredness scores provided by women in

Magnetic Resonance Imaging Measurement of Left Ventricular Blood Flow and Coronary Flow Reserve in Patients with Chronic Heart Failure due to Coronary Artery Disease

International Nuclear Information System (INIS)

Aras, A.; Anik, Y.; Demirci, A.; Balci, N.C.; Kozdag, G.; Ural, D.; Komsuogl u, B.

2007-01-01

Background: Coronary sinus flow reflects global cardiac perfusion and has been used for the assessment of myocardial flow reserve, which is reduced in chronic heart failure (CHF). Coronary flow reserve (CFR) can be measured by using phase-contrast (PC) velocity-encoded cine (VEC) magnetic resonance imaging (MRI). Purpose: To quantify and compare global left ventricular (LV) perfusion and CFR in patients with CHF and in a healthy control group by measuring coronary sinus flow with PC VEC MRI, and to correlate this with global LV perfusion, segmental first-pass perfusion, and viability in the same patients. Material and Methods: Cardiac MRI was performed in 20 patients with CHF of ischemic origin and in a control group of healthy subjects (n 11) at rest and after pharmacological stress induced by i.v. dipyridamole. The MRI protocol included cine MRI, VEC MRI, first-pass perfusion, and delayed contrast-enhanced MRI for viability. Global LV perfusion was quantified by measuring coronary sinus flow on VEC MRI at rest in all subjects. CFR was determined as the ratio of global LV perfusion before and after pharmacologic stress. Results: At rest, global LV perfusion was not significantly different in patients with CHF and the control group. After administration of dipyridamole, global LV perfusion and CFR were significantly lower in patients with CHF compared to the control group (P<0.001). An inverse correlation was observed between CFR and the number of infarcted and/or ischemic segments (P = 0.083, P 0.037). Conclusion: A combined cardiac MRI protocol including function and perfusion techniques together with VEC MRI can be used to evaluate global LV perfusion and CFR in patients with CHF. Global LV perfusion and CFR measurements may have potential in the monitoring of CHF. Impaired CFR may contribute to progressive decline in LV function in patients with CHF

Magnetic Resonance Imaging Measurement of Left Ventricular Blood Flow and Coronary Flow Reserve in Patients with Chronic Heart Failure due to Coronary Artery Disease

Energy Technology Data Exchange (ETDEWEB)

Aras, A.; Anik, Y.; Demirci, A.; Balci, N.C.; Kozdag, G.; Ural, D.; Komsuoglu, B. (Radiology Dept. and Cardiology Dept., Kocaeli Univ. School of Medicine, Kocaeli (Turkey))

2007-11-15

Background: Coronary sinus flow reflects global cardiac perfusion and has been used for the assessment of myocardial flow reserve, which is reduced in chronic heart failure (CHF). Coronary flow reserve (CFR) can be measured by using phase-contrast (PC) velocity-encoded cine (VEC) magnetic resonance imaging (MRI). Purpose: To quantify and compare global left ventricular (LV) perfusion and CFR in patients with CHF and in a healthy control group by measuring coronary sinus flow with PC VEC MRI, and to correlate this with global LV perfusion, segmental first-pass perfusion, and viability in the same patients. Material and Methods: Cardiac MRI was performed in 20 patients with CHF of ischemic origin and in a control group of healthy subjects (n 11) at rest and after pharmacological stress induced by i.v. dipyridamole. The MRI protocol included cine MRI, VEC MRI, first-pass perfusion, and delayed contrast-enhanced MRI for viability. Global LV perfusion was quantified by measuring coronary sinus flow on VEC MRI at rest in all subjects. CFR was determined as the ratio of global LV perfusion before and after pharmacologic stress. Results: At rest, global LV perfusion was not significantly different in patients with CHF and the control group. After administration of dipyridamole, global LV perfusion and CFR were significantly lower in patients with CHF compared to the control group (P<0.001). An inverse correlation was observed between CFR and the number of infarcted and/or ischemic segments (P = 0.083, P = 0.037). Conclusion: A combined cardiac MRI protocol including function and perfusion techniques together with VEC MRI can be used to evaluate global LV perfusion and CFR in patients with CHF. Global LV perfusion and CFR measurements may have potential in the monitoring of CHF. Impaired CFR may contribute to progressive decline in LV function in patients with CHF

Hypogonadotropic hypogonadism: new identification of testicular blood flow and varicocele after treatment with gonadotropins.

Science.gov (United States)

ur Rehman, Khaleeq; Shahid, Khubaib; Humayun, Hina

2014-09-01

To investigate testicular changes in patients with hypogonadotropic hypogonadism (HH) after treatment with gonadotropins. Patients with HH were investigated and followed before and after treatment. Urology and andrology clinic of a teaching hospital. Consecutive male patients with diagnosed HH. All patients were treated with gonadotropins during the study period and later. The hormonal status and scrotal color Doppler ultrasound (CDUS) of patients was recorded before and after treatment. Twenty-six patients with HH (ages 18-43 years) were followed for 8-29 months. After treatment, serum T and secondary sex characters improved in all and spermatogenesis developed in 61.5% of patients. Before treatment, testicular (intraparenchymal blood flow) was undetectable in all and barely detectable in three patients. This improved significantly to 4.53±5.44 and 4.27±4.97 cm/second, respectively, after treatment. Subcapsular arterial flow and testicular size also improved significantly. Similarly, after treatment, transverse epididymal diameter (TED) increased significantly. At baseline, no patient had detectable varicocele on CDUS. After treatment, varicocele was demonstrable in 23% of patients. This finding was further evaluated retrospectively from our 76 HH patient files. None of them had varicocele before treatment, but after treatment 19.73% were found to have varicocele. Patients with HH responded to gonadotropins by improvement in testicular blood flow and increase in TED. In some patients, varicocele was found to develop after treatment. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

An improved approach for flow-based cloud point extraction.

Science.gov (United States)

Frizzarin, Rejane M; Rocha, Fábio R P

2014-04-11

Novel strategies are proposed to circumvent the main drawbacks of flow-based cloud point extraction (CPE). The surfactant-rich phase (SRP) was directly retained into the optical path of the spectrophotometric cell, thus avoiding its dilution previously to the measurement and yielding higher sensitivity. Solenoid micro-pumps were exploited to improve mixing by the pulsed flow and also to modulate the flow-rate for retention and removal of the SRP, thus avoiding the elution step, often carried out with organic solvents. The heat released and the increase of the salt concentration provided by an on-line neutralization reaction were exploited to induce the cloud point without an external heating device. These innovations were demonstrated by the spectrophotometric determination of iron, yielding a linear response from 10 to 200 μg L(-1) with a coefficient of variation of 2.3% (n=7). Detection limit and sampling rate were estimated at 5 μg L(-1) (95% confidence level) and 26 samples per hour, respectively. The enrichment factor was 8.9 and the procedure consumed only 6 μg of TAN and 390 μg of Triton X-114 per determination. At the 95% confidence level, the results obtained for freshwater samples agreed with the reference procedure and those obtained for digests of bovine muscle, rice flour, brown bread and tort lobster agreed with the certified reference values. The proposed procedure thus shows advantages in relation to previously proposed approaches for flow-based CPE, being a fast and environmental friendly alternative for on-line separation and pre-concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

Involving patients in care decisions improves satisfaction: an outcomes-based quality improvement project.

Science.gov (United States)

Leff, Ellen W

2004-05-01

A home care agency used quality improvement processes to improve patient satisfaction survey ratings. The focus was on involving patients in decisions about their care. A multidisciplinary team developed creative strategies to increase staff awareness and enhance customer service skills, which had dramatic results.

Evaluation of plasma eosinophil count and mean platelet volume in patients with coronary slow flow

Directory of Open Access Journals (Sweden)

Mehmet Demir

2014-01-01

Full Text Available OBJECTIVE: The pathophysiology of coronary slow flow has not been clearly defined, although multiple abnormalities including arteritis, endothelial dysfunction, and atherothrombosis, have been reported. It is known that eosinophils play an important role in inflammation, endothelial dysfunction, and thrombosis. We aimed to compare the eosinophil counts of coronary slow flow patients versus healthy controls. METHODS: This study included 50 coronary slow flow patients (19 males, mean age 65.6±13.7 years and 30 healthy controls (10 males, mean age 57.86±11.6 years. These participants were evaluated using concurrent routine biochemical tests as well as neutrophil, lymphocyte, and eosinophil counts and mean platelet volume (MPV, which were obtained from the whole blood count. These parameters were compared between groups. RESULTS: The baseline characteristics of the study groups were comparable. The coronary slow flow patients had a higher mean platelet volume and eosinophil count than the control group (8.38±0.86 vs 6.28±1.6 fL and 0.31±0.42 vs 0.09±0.05; p<0.001 and 0.008, respectively. CONCLUSION: Our study demonstrated a relationship between eosinophil count and MPV in patients with coronary slow flow.

Application of the Novel Ventilation Mode FLow-Controlled EXpiration (FLEX): A Crossover Proof-of-Principle Study in Lung-Healthy Patients.

Science.gov (United States)

Wirth, Steffen; Springer, Sebastian; Spaeth, Johannes; Borgmann, Silke; Goebel, Ulrich; Schumann, Stefan

2017-10-01

Traditionally, mechanical ventilation is achieved via active lung inflation during inspiration and passive lung emptying during expiration. By contrast, the novel FLEX (FLow-controlled EXpiration) ventilator mode actively decreases the rate of lung emptying. We investigated whether FLEX can be used during intraoperative mechanical ventilation of lung-healthy patients. In 30 adult patients scheduled for neurosurgical procedures, we studied respiratory system mechanics, regional ventilation, oxygenation, and hemodynamics during ventilation with and without FLEX at positive end-expiratory pressure (PEEP) of 5 and 7 cm H2O. The FLEX system was integrated into the expiratory limb and modified the expiratory flow profile by continuously changing expiratory resistance according to a computer-controlled algorithm. Mean airway pressure increased with PEEP by 1.9 cm H2O and with FLEX by 1 cm H2O (all P ventilated during general anesthesia. FLEX improves the homogeneous distribution of ventilation in the lungs.

Network analysis of patient flow in two UK acute care hospitals identifies key sub-networks for A&E performance.

Science.gov (United States)

Bean, Daniel M; Stringer, Clive; Beeknoo, Neeraj; Teo, James; Dobson, Richard J B

2017-01-01

The topology of the patient flow network in a hospital is complex, comprising hundreds of overlapping patient journeys, and is a determinant of operational efficiency. To understand the network architecture of patient flow, we performed a data-driven network analysis of patient flow through two acute hospital sites of King's College Hospital NHS Foundation Trust. Administration databases were queried for all intra-hospital patient transfers in an 18-month period and modelled as a dynamic weighted directed graph. A 'core' subnetwork containing only 13-17% of all edges channelled 83-90% of the patient flow, while an 'ephemeral' network constituted the remainder. Unsupervised cluster analysis and differential network analysis identified sub-networks where traffic is most associated with A&E performance. Increased flow to clinical decision units was associated with the best A&E performance in both sites. The component analysis also detected a weekend effect on patient transfers which was not associated with performance. We have performed the first data-driven hypothesis-free analysis of patient flow which can enhance understanding of whole healthcare systems. Such analysis can drive transformation in healthcare as it has in industries such as manufacturing.

Improvement of Power Flow Calculation with Optimization Factor Based on Current Injection Method

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Lei Wang

2014-01-01

Full Text Available This paper presents an improvement in power flow calculation based on current injection method by introducing optimization factor. In the method proposed by this paper, the PQ buses are represented by current mismatches while the PV buses are represented by power mismatches. It is different from the representations in conventional current injection power flow equations. By using the combined power and current injection mismatches method, the number of the equations required can be decreased to only one for each PV bus. The optimization factor is used to improve the iteration process and to ensure the effectiveness of the improved method proposed when the system is ill-conditioned. To verify the effectiveness of the method, the IEEE test systems are tested by conventional current injection method and the improved method proposed separately. Then the results are compared. The comparisons show that the optimization factor improves the convergence character effectively, especially that when the system is at high loading level and R/X ratio, the iteration number is one or two times less than the conventional current injection method. When the overloading condition of the system is serious, the iteration number in this paper appears 4 times less than the conventional current injection method.

Long-term effects of oxygen-enriched high-flow nasal cannula treatment in COPD patients with chronic hypoxemic respiratory failure

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Storgaard LH

2018-04-01

Full Text Available Line Hust Storgaard,1 Hans-Ulrich Hockey,2 Birgitte Schantz Laursen,3,4 Ulla Møller Weinreich1,3 1Department of Respiratory Diseases, Aalborg University Hospital, Aalborg, Denmark; 2Biometrics Matters Limited, Hamilton, New Zealand; 3Department of Clinical Medicine, Aalborg University, Aalborg, Denmark; 4Clinical Nursing Research Unit, Aalborg University Hospital, Aalborg, Denmark Background: This study investigated the long-term effects of humidified high-flow nasal cannula (HFNC in COPD patients with chronic hypoxemic respiratory failure treated with long-term oxygen therapy (LTOT.Patients and methods: A total of 200 patients were randomized into usual care ± HFNC. At inclusion, acute exacerbation of COPD (AECOPD and hospital admissions 1 year before inclusion, modified Medical Research Council (mMRC score, St George’s Respiratory Questionnaire (SGRQ, forced expiratory volume in 1 second (FEV1, 6-minute walk test (6MWT and arterial carbon dioxide (PaCO2 were recorded. Patients completed phone interviews at 1, 3 and 9 months assessing mMRC score and AECOPD since the last contact. At on-site visits (6 and 12 months, mMRC, number of AECOPD since last contact and SGRQ were registered and FEV1, FEV1%, PaCO2 and, at 12 months, 6MWT were reassessed. Hospital admissions during the study period were obtained from hospital records. Hours of the use of HFNC were retrieved from the high-flow device.Results: The average daily use of HFNC was 6 hours/day. The HFNC group had a lower AECOPD rate (3.12 versus 4.95/patient/year, p<0.001. Modeled hospital admission rates were 0.79 versus 1.39/patient/year for 12- versus 1-month use of HFNC, respectively (p<0.001. The HFNC group had improved mMRC scores from 3 months onward (p<0.001 and improved SGRQ at 6 and 12 months (p=0.002, p=0.033 and PaCO2 (p=0.005 and 6MWT (p=0.005 at 12 months. There was no difference in all-cause mortality.Conclusion: HFNC treatment reduced AECOPD, hospital admissions and

The use of high-flow nasal cannula in the pediatric emergency department

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Katherine N. Slain

Full Text Available Abstract Objectives: To summarize the current literature describing high-flow nasal cannula use in children, the components and mechanisms of action of a high-flow nasal cannula system, the appropriate clinical applications, and its role in the pediatric emergency department. Sources: A computer-based search of PubMed/MEDLINE and Google Scholar for literature on high-flow nasal cannula use in children was performed. Data summary: High-flow nasal cannula, a non-invasive respiratory support modality, provides heated and fully humidified gas mixtures to patients via a nasal cannula interface. High-flow nasal cannula likely supports respiration though reduced inspiratory resistance, washout of the nasopharyngeal dead space, reduced metabolic work related to gas conditioning, improved airway conductance and mucociliary clearance, and provision of low levels of positive airway pressure. Most data describing high-flow nasal cannula use in children focuses on those with bronchiolitis, although high-flow nasal cannula has been used in children with other respiratory diseases. Introduction of high-flow nasal cannula into clinical practice, including in the emergency department, has been associated with decreased rates of endotracheal intubation. Limited prospective interventional data suggest that high-flow nasal cannula may be similarly efficacious as continuous positive airway pressure and more efficacious than standard oxygen therapy for some patients. Patient characteristics, such as improved tachycardia and tachypnea, have been associated with a lack of progression to endotracheal intubation. Reported adverse effects are rare. Conclusions: High-flow nasal cannula should be considered for pediatric emergency department patients with respiratory distress not requiring immediate endotracheal intubation; prospective, pediatric emergency department-specific trials are needed to better determine responsive patient populations, ideal high-flow nasal cannula

An Improved Scale-Adaptive Simulation Model for Massively Separated Flows

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Yue Liu

2018-01-01

Full Text Available A new hybrid modelling method termed improved scale-adaptive simulation (ISAS is proposed by introducing the von Karman operator into the dissipation term of the turbulence scale equation, proper derivation as well as constant calibration of which is presented, and the typical circular cylinder flow at Re = 3900 is selected for validation. As expected, the proposed ISAS approach with the concept of scale-adaptive appears more efficient than the original SAS method in obtaining a convergent resolution, meanwhile, comparable with DES in visually capturing the fine-scale unsteadiness. Furthermore, the grid sensitivity issue of DES is encouragingly remedied benefiting from the local-adjusted limiter. The ISAS simulation turns out to attractively represent the development of the shear layers and the flow profiles of the recirculation region, and thus, the focused statistical quantities such as the recirculation length and drag coefficient are closer to the available measurements than DES and SAS outputs. In general, the new modelling method, combining the features of DES and SAS concepts, is capable to simulate turbulent structures down to the grid limit in a simple and effective way, which is practically valuable for engineering flows.

Impact of pacing modality and biventricular pacing on cardiac output and coronary conduit flow in the post-cardiotomy patient.

LENUS (Irish Health Repository)

Healy, David G

2012-02-03

We have previously demonstrated the role of univentricular pacing modalities in influencing coronary conduit flow in the immediate post-operative period in the cardiac surgery patient. We wanted to determine the mechanism of this improved coronary conduit and, in addition, to explore the possible benefits with biventricular pacing. Sixteen patients undergoing first time elective coronary artery bypass grafting who required pacing following surgery were recruited. Comparison of cardiac output and coronary conduit flow was performed between VVI and DDD pacing with a single right ventricular lead and biventricular pacing lead placement. Cardiac output was measured using arterial pulse waveform analysis while conduit flow was measured using ultrasonic transit time methodology. Cardiac output was greatest with DDD pacing using right ventricular lead placement only [DDD-univentricular 5.42 l (0.7), DDD-biventricular 5.33 l (0.8), VVI-univentricular 4.71 l (0.8), VVI-biventricular 4.68 l (0.6)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.023) and VVI-biventricular pacing (P=0.001) but there was no significant advantage to DDD-biventricular pacing (P=0.45). In relation to coronary conduit flow, DDD pacing again had the highest flow [DDD-univentricular 55 ml\\/min (24), DDD-biventricular 52 ml\\/min (25), VVI-univentricular 47 ml\\/min (23), VVI-biventricular 50 ml\\/min (26)]. DDD-univentricular pacing was significantly better than VVI-univentricular (P=0.006) pacing but not significantly different to VVI-biventricular pacing (P=0.109) or DDD-biventricular pacing (P=0.171). Pacing with a DDD modality offers the optimal coronary conduit flow by maximising cardiac output. Biventricular lead placement offered no significant benefit to coronary conduit flow or cardiac output.

Demand dynamic bio-girdling in heart failure: improved efficacy of dynamic cardiomyoplasty by LD contraction during aortic out-flow.

Science.gov (United States)

Carraro, U; Rigatelli, G; Rossini, K; Barbiero, M; Rigatelli, G

2003-03-01

The value of dynamic cardiomyoplasty has been brought into question by the disappointing results produced by slow contraction-relaxation cycle and possibly degeneration of the latissimus dorsi muscle (LD) secondary to temporary tenotomy and chronic daily electrical stimulation. Objective of our study is to determine whether daily periods of rest introduced by demand stimulation in the continuous contraction protocol produce systolic assistance and improve clinical results. Twelve dynamic cardiomyoplasty patients (mean age 58.2 +/- 5.8 years, M/F=11/1, sinus rhythm/atrial fibrillation=11/1) with dilated myocardiopathy were enrolled in an unrandomized trial of Demand Dynamic Heart Bio-Girdling in a public regional teaching hospital. Periods of LD inactivity, each lasting several hours, were introduced daily on a heart rate-based demand regime. To avoid full transformation of LD, fewer impulses per day were delivered, daily providing the LD with long periods of rest (Demand light stimulation). The contractile properties were measured by transcutaneous non-invasive LD tensiomyogram interrogation (LD tensiomyogram). Bio-Girdle activation was synchronized to heart beat by combining tensiomyogram and echocardiography. Clinical, echocardiographic and hemodynamic records, as well as aortic flow measurements by Doppler aortic flow wire were taken during the follow-up. Mean duration of the demand stimulation follow-up was 40.2+13.8 months. At five years, "Demand stimulation" shows: 1) no operative death; 2) 83% actuarial survival; 3) highly significant 47.4% decrease of the NYHA class (from 3.17 +/- 0.38 to 1.67 +/- 0.77, p=0.0001); 4) 41.6% improvement of LVEF (from 22.6 +/- 4.38 to 32.0 +/- 7.0, p=0.001); 5) 7.5 +/- 3.0% increase in aortic flow velocity peak in assisted vs. unassisted beats, and 6) preservation of LD from slowness (TFF value 33 +/- 7.86 at follow-up versus 15.8 +/- 11.1 Hz just before switching from continuous to demand stimulation, p=0.0001) and muscle

Orthogeriatric care: improving patient outcomes

Directory of Open Access Journals (Sweden)

Tarazona-Santabalbina FJ

2016-06-01

Full Text Available Francisco José Tarazona-Santabalbina,1,2 Ángel Belenguer-Varea,1,2 Eduardo Rovira,1,2 David Cuesta-Peredó1,21Geriatric Medicine Unit, Internal Medicine Department, Hospital Universitario de la Ribera, 2Medical School, Universidad Católica de Valencia San vicente Mártir, Valencia, SpainAbstract: Hip fractures are a very serious socio-economic problem in western countries. Since the 1950s, orthogeriatric units have introduced improvements in the care of geriatric patients admitted to hospital because of hip fractures. During this period, these units have reduced mean hospital stays, number of complications, and both in-hospital mortality and mortality over the middle term after hospital discharge, along with improvements in the quality of care and a reduction in costs. Likewise, a recent clinical trial has reported greater functional gains among the affected patients. Studies in this field have identified the prognostic factors present upon admission or manifesting themselves during admission and that increase the risk of patient mortality or disability. In addition, improved care afforded by orthogeriatric units has proved to reduce costs. Nevertheless, a number of management issues remain to be clarified, such as the optimum anesthetic, analgesic, and thromboprophylactic protocols; the type of diagnostic and therapeutic approach best suited to patients with cognitive problems; or the efficiency of the programs used in convalescence units or in home rehabilitation care. Randomized clinical trials are needed to consolidate the evidence in this regard. Keywords: hip fractures, geriatric assessment, orthogeriatric care, recovery of function, mortality

Myocardial blood flow assessment with {sup 82}rubidium-PET imaging in patients with left bundle branch block

Energy Technology Data Exchange (ETDEWEB)

Falcao, Andrea; Chalela, William; Giorgi, Maria Clementina; Imada, Rodrigo; Soares Junior, Jose; Do Val, Renata; Oliveira, Marco Antonio; Izaki, Marisa; Kalil Filho, Roberto; Meneghetti, Jose C., E-mail: andrea.falcao@incor.usp.br [Universidade de Sao Paulo (InCor/USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Instituto do Coracao

2015-11-15

Objectives: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. Objective: we sought to investigate rubidium-82 ({sup 82}Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. Methods: thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress {sup 82}Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal {sup 82}Rb-positron emission tomography studies and without left bundle branch block (GII). Results: stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p>0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). Conclusion: the data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by {sup 82}Rb-positron emission tomography imaging may be useful in identifying coronary artery

Evaluation of salivary glucose, IgA and flow rate in diabetic patients: a case-control study.

Science.gov (United States)

Bakianian Vaziri, P; Vahedi, M; Mortazavi, H; Abdollahzadeh, Sh; Hajilooi, M

2010-01-01

An association between diabetes mellitus and alterations in the oral cavity has been noted. In this study, we evaluated differences between salivary IgA, glucose and flow rate in diabetic patients compared with healthy controls. Forty patients with type 1 diabetes, 40 patients with type 2 diabetes and 40 healthy controls were selected. Whole unstimulated saliva samples were collected by the standard method and the salivary flow rate was determined. Nephelometric and Pars method were used to measure salivary IgA and salivary glucose concentrations, respectively. Statistical analysis was performed by Chi-square and t test. There were no significant differences in salivary IgA and glucose concentrations between type 1 and type 2 diabetic patients and their matched control subjects (P>0.05). Salivary flow rate was significantly lower in diabetic patients (Pdiabetic patients than the controls. Determination of salivary constituents may be useful in the description and management of oral findings in diabetic patients.

An improved anisotropy-resolving subgrid-scale model for flows in laminar–turbulent transition region

International Nuclear Information System (INIS)

Inagaki, Masahide; Abe, Ken-ichi

2017-01-01

Highlights: • An anisotropy-resolving subgrid-scale model, covering a wide range of grid resolutions, is improved. • The new model enhances its applicability to flows in the laminar-turbulent transition region. • A mixed-timescale subgrid-scale model is used as the eddy viscosity model. • The proposed model successfully predicts the channel flows at transitional Reynolds numbers. • The influence of the definition of the grid-filter width is also investigated. - Abstract: Some types of mixed subgrid-scale (SGS) models combining an isotropic eddy-viscosity model and a scale-similarity model can be used to effectively improve the accuracy of large eddy simulation (LES) in predicting wall turbulence. Abe (2013) has recently proposed a stabilized mixed model that maintains its computational stability through a unique procedure that prevents the energy transfer between the grid-scale (GS) and SGS components induced by the scale-similarity term. At the same time, since this model can successfully predict the anisotropy of the SGS stress, the predictive performance, particularly at coarse grid resolutions, is remarkably improved in comparison with other mixed models. However, since the stabilized anisotropy-resolving SGS model includes a transport equation of the SGS turbulence energy, k SGS , containing a production term proportional to the square root of k SGS , its applicability to flows with both laminar and turbulent regions is not so high. This is because such a production term causes k SGS to self-reproduce. Consequently, the laminar–turbulent transition region predicted by this model depends on the inflow or initial condition of k SGS . To resolve these issues, in the present study, the mixed-timescale (MTS) SGS model proposed by Inagaki et al. (2005) is introduced into the stabilized mixed model as the isotropic eddy-viscosity part and the production term in the k SGS transport equation. In the MTS model, the SGS turbulence energy, k es , estimated by

Assessment of cerebral blood flow reserve using blood oxygen level-dependent echo planar imaging after acetazolamide administration in patients post-STA-MCA anastomosis surgery

International Nuclear Information System (INIS)

Zenke, Kiichiro; Kusunoki, Katsusuke; Saito, Masahiro; Sadamoto, Kazuhiko; Ohta, Shinsuke; Kumon, Yoshiaki; Sakaki, Saburo; Nagasawa, Kiyoshi

1998-01-01

Recently, blood oxygen level-dependent (BOLD) echo planar imaging (EPI) has been used to estimate blood flow changes. Theoretically, a relative decrement of deoxyhemoglobin in cerebral blood supply induces a MR signal change after neuronal stimulation. In the present study, we have attempted to evaluate CBF reserve capacity by the BOLD EPI in patients who had undergone STA-MCA anastomosis surgery. Then, we compared with the signal intensity changes obtained by this procedure with the CBF changes by Xe-SPECT after acetazolamide administration. Six patients, post-STA-MCA anastomosis surgery, were studied. Pre-operatively, MR signal intensity and CBF, by Xe-SPECT, were increased in the intact side after acetazolamide administration in all patients, and MR signal intensities were decreased in low flow regions after acetazolamide administration in all four patients in whom so-called steal phenomenon was demonstrated by Xe-SPECT study. Post-operatively, poor response was shown after acetazolamide administration with both Xe-SPECT and BOLD EPI in the two patients who had unsuccessful anastomoses. In the successfully anastomosed patients, improved vascular reactivity was demonstrated on BOLD EPI after acetazolamide administration in 3 of 4 patients in whom an improvement of vascular reactivity was demonstrated on Xe-SPECT. In one patient, MRI studies were considered to have technical artifacts, because the MR signal intensity did not increase, even in the intact side after acetazolamide administration. In conclusion, BOLD EPI after acetazolamide administration is an useful procedure for the pre- and post-operative of vascular reserve in patients with ischemic stroke. (author)

Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome

DEFF Research Database (Denmark)

Storgaard, Filip Holst; Pedersen, Christina Gravgaard; Jensen, Majbritt Lykke

Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome.......Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome....

Effect of perturbations and a meal on superior mesenteric artery flow in patients with orthostatic hypotension

Science.gov (United States)

Fujimura, J.; Camilleri, M.; Low, P. A.; Novak, V.; Novak, P.; Opfer-Gehrking, T. L.

1997-01-01

Our aims were to evaluate to role of superior mesenteric blood flow in the pathophysiology of orthostatic hypotension in patients with generalized autonomic failure. METHODS: Twelve patients with symptomatic neurogenic orthostatic hypotension and 12 healthy controls underwent superior mesenteric artery flow measurements using Doppler ultrasonography during head-up tilt and tilt plus meal ingestion. Autonomic failure was assessed using standard tests of the function of the sympathetic adrenergic, cardiovagal and postganglionic sympathetic sudomotor function. RESULTS: Superior mesenteric flow volume and time-averaged velocity were similar in patients and controls at supine rest; however, responses to cold pressor test and upright tilt were attenuated (p stress can be significantly attenuated by reducing the splanchnic-mesenteric volume increase in response to food. Evaluation of mesenteric flow in response to eating and head-up tilt provide important information on intra-abdominal sympathetic adrenergic function, and the ability of the patient to cope with orthostatic stress.

Using optical fibers with different modes to improve the signal-to-noise ratio of diffuse correlation spectroscopy flow-oximeter measurements

Science.gov (United States)

He, Lian; Lin, Yu; Shang, Yu; Shelton, Brent J.; Yu, Guoqiang

2013-03-01

The dual-wavelength diffuse correlation spectroscopy (DCS) flow-oximeter is an emerging technique enabling simultaneous measurements of blood flow and blood oxygenation changes in deep tissues. High signal-to-noise ratio (SNR) is crucial when applying DCS technologies in the study of human tissues where the detected signals are usually very weak. In this study, single-mode, few-mode, and multimode fibers are compared to explore the possibility of improving the SNR of DCS flow-oximeter measurements. Experiments on liquid phantom solutions and in vivo muscle tissues show only slight improvements in flow measurements when using the few-mode fiber compared with using the single-mode fiber. However, light intensities detected by the few-mode and multimode fibers are increased, leading to significant SNR improvements in detections of phantom optical property and tissue blood oxygenation. The outcomes from this study provide useful guidance for the selection of optical fibers to improve DCS flow-oximeter measurements.

Correlation between voluntary cough and laryngeal cough reflex flows in patients with traumatic brain injury.

Science.gov (United States)

Lee, Sang Chul; Kang, Seong-Woong; Kim, Min Tae; Kim, Yong Kyun; Chang, Won Hyuk; Im, Sang Hee

2013-08-01

To correlate voluntary cough and laryngeal cough reflex (LCR) flows in patients with traumatic brain injury (TBI). Cross-sectional study. University rehabilitation hospital. Patients with TBI (n=25) and healthy controls (n=48). Not applicable. Peak cough flows (PCFs) and LCR flows were measured using a peak flow meter at the oral-nasal interface. The largest value of 3 attempts was recorded for PCF and LCR, respectively. LCR was elicited by 20% solution of pharmaceutic-grade citric acid dissolved in sterile .15M NaCl solution that was inhaled from a nebulizer. PCF was 447.4 ± 99.0 L/min in the control group and 211.7 ± 58.2 L/min in the patient group. LCR was 209.2 ± 63.8L/min in the control group and 170.0 ± 59.7 L/min in the patient group. Both PCF (P=.000) and LCR (P=.013) were significantly reduced in patients with TBI compared to that of the control group. LCR was strongly related to the PCF in both control (R=.645; P=.000) and patient (R=.711; P=.000) groups. As LCR can be measured as a numerical value and significantly correlates with PCF, LCR can be used to estimate cough ability of patients with TBI who cannot cooperate with PCF measurement. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Critical transport issues for improving the performance of aqueous redox flow batteries

Science.gov (United States)

Zhou, X. L.; Zhao, T. S.; An, L.; Zeng, Y. K.; Wei, L.

2017-01-01

As the fraction of electricity generated from intermittent renewable sources (such as solar and wind) grows, developing reliable energy storage technologies to store electrical energy in large scale is of increasing importance. Redox flow batteries are now enjoying a renaissance and regarded as a leading technology in providing a well-balanced solution for current daunting challenges. In this article, state-of-the-art studies of the complex multicomponent transport phenomena in aqueous redox flow batteries, with a special emphasis on all-vanadium redox flow batteries, are reviewed and summarized. Rather than elaborating on the details of previous experimental and numerical investigations, this article highlights: i) the key transport issues in each battery's component that need to be tackled so that the rate capability and cycling stability of flow batteries can be significantly improved, ii) the basic mechanisms that control the active species/ion/electron transport behaviors in each battery's component, and iii) the key experimental and numerical findings regarding the correlations between the multicomponent transport processes and battery performance.

Regional cerebral blood flow in diabetic patients

International Nuclear Information System (INIS)

Nagamachi, Shigeki; Ono, Shinnichi; Nishikawa, Takushi

1993-01-01

N-isopropyl-p- 123 I-iodoamphetamine (IMP) was used to quantify the regional cerebral blood flow (r-CBF) in 11 diabetic patients (average age; 67.9 years) and 12 non-diabetic subjects (average age; 67.4 years), none of whom had (cerebrovascular disease (CVD) on CT studies. A reference sampling method by continuous arterial blood sampling was used to quantify r-CBF. There were no significant differences in physiological or laboratory data between diabetic and non-diabetic groups except for fasting plasma glucose and HbA 1c levels. The average of r-CBF in each region of cerebrum and cerebellum was significantly lower in diabetic group than that in the control group (p<0.01). These observations show that r-CBF of diabetic patients is reduced, even in the absence of findings of CVD on a CT study. (author)

Developing patient-centred care: an ethnographic study of patient perceptions and influence on quality improvement.

Science.gov (United States)

Renedo, Alicia; Marston, Cicely

2015-04-23

Understanding quality improvement from a patient perspective is important for delivering patient-centred care. Yet the ways patients define quality improvement remains unexplored with patients often excluded from improvement work. We examine how patients construct ideas of 'quality improvement' when collaborating with healthcare professionals in improvement work, and how they use these understandings when attempting to improve the quality of their local services. We used in-depth interviews with 23 'patient participants' (patients involved in quality improvement work) and observations in several sites in London as part of a four-year ethnographic study of patient and public involvement (PPI) activities run by Collaborations for Leadership in Applied Health Research and Care for Northwest London. We took an iterative, thematic and discursive analytical approach. When patient participants tried to influence quality improvement or discussed different dimensions of quality improvement their accounts and actions frequently started with talk about improvement as dependent on collective action (e.g. multidisciplinary healthcare professionals and the public), but usually quickly shifted away from that towards a neoliberal discourse emphasising the role of individual patients. Neoliberal ideals about individual responsibility were taken up in their accounts moving them away from the idea of state and healthcare providers being held accountable for upholding patients' rights to quality care, and towards the idea of citizens needing to work on self-improvement. Participants portrayed themselves as governed by self-discipline and personal effort in their PPI work, and in doing so provided examples of how neoliberal appeals for self-regulation and self-determination also permeated their own identity positions. When including patient voices in measuring and defining 'quality', governments and public health practitioners should be aware of how neoliberal rationalities at the

Three-dimensional flow analysis and improvement of slip factor model for forward-curved blades centrifugal fan

International Nuclear Information System (INIS)

Guo, En Min; Kim, Kwang Yong

2004-01-01

This work developed improved slip factor model and correction method to predict flow through impeller in forward-curved centrifugal fan. Both steady and unsteady three-dimensional CFD analyses were performed to validate the slip factor model and the correction method. The results show that the improved slip factor model presented in this paper could provide more accurate predictions for forward-curved centrifugal impeller than the other slip factor models since the present model takes into account the effect of blade curvature. The correction method is provided to predict mass-averaged absolute circumferential velocity at the exit of impeller by taking account of blockage effects induced by the large-scale backflow near the front plate and flow separation within blade passage. The comparison with CFD results also shows that the improved slip factor model coupled with the present correction method provides accurate predictions for mass-averaged absolute circumferential velocity at the exit of impeller near and above the flow rate of peak total pressure coefficient

Improved patient-reported health impact of multiple sclerosis

DEFF Research Database (Denmark)

Macdonell, Richard; Nagels, Guy; Laplaud, David-Axel

2016-01-01

BACKGROUND: Multiple sclerosis (MS) is a debilitating disease that negatively impacts patients' lives. OBJECTIVE: ENABLE assessed the effect of long-term prolonged-release (PR) fampridine (dalfampridine extended release in the United States) treatment on patient-perceived health impact in patients...... with MS with walking impairment. METHODS: ENABLE was a 48-week, open-label, Phase 4 study of PR-fampridine 10 mg twice daily. Patients who showed any improvement in Timed 25-Foot Walk walking speed at weeks 2 and 4 and any improvement in 12-item MS Walking Scale score at week 4 remained on treatment....... The primary endpoint was change from baseline in 36-Item Short-Form Health Survey (SF-36) physical component summary (PCS) score. RESULTS: At week 4, 707/901 (78.5%) patients met the criteria to remain on treatment. Patients on treatment demonstrated significant and clinically meaningful improvements in SF-36...

Fast-flow lingual vascular anomalies in the young patient: is imaging diagnostic?

International Nuclear Information System (INIS)

Khong, Pek-Lan; Burrows, Patricia E.; Kozakewich, Harry P.; Mulliken, John B.

2003-01-01

To describe the imaging findings (MR imaging and angiography) of high-flow vascular anomalies of the tongue, hemangiomas and arteriovenous malformations (AVMs), with emphasis on the discrepant imaging findings in lingual AVMs. Retrospective review of clinical records, histologic reports and imaging studies of five consecutive patients with high-flow lingual vascular anomalies. One patient had hemangioma (aged 1 month) and four patients had AVMs (aged 15 months, 6, 24, and 33 years). Diagnosis was made on the basis of histology in four lesions and was based on typical clinical history in one lesion. MR imaging and angiographic findings of the hemangioma were typical, but similar findings of focal hyperintense mass on T2-weighted images and angiographic stain were seen in three AVMs (patients aged 15 months, 6 and 33 years). On angiography, there was no nidus or direct arteriovenous (AV) shunting in one AVM (patient aged 15 months). The fourth AVM had typical MR imaging and angiographic findings. The imaging findings in lingual AVMs can be atypical or inconclusive and can mimic hemangiomas, especially in the young patient. Since treatment depends on accurate diagnosis, biopsy may be necessary for lesions with inconclusive imaging findings. (orig.)

Effect of High-Flow Nasal Cannula versus Conventional Oxygen Therapy for Patients with Thoracoscopic Lobectomy after Extubation

Directory of Open Access Journals (Sweden)

Yuetian Yu

2017-01-01

Full Text Available Objective. To investigate whether high-flow nasal cannula (HFNC oxygen therapy is superior to conventional oxygen therapy for reducing hypoxemia and postoperative pulmonary complications (PPC in patients with thoracoscopic lobectomy after extubation. Methods. Patients with intermediate to high risk for PPC were enrolled in this study. Subjects were randomly assigned to HFNC group (HFNCG or conventional oxygen group (COG following extubation. Arterial blood samples were collected after extubation at 1, 2, 6, 12, 24, 48, and 72 h. Patients with postoperative hypoxemia and PPC were recorded. Adverse events were also documented. Results. Totally 110 patients were randomly assigned to HFNCG (n=56 and COG (n=54. The occurrence rate of hypoxemia in COG was twice more than that in HFNCG (29.62% versus 12.51%, P0.05. Adverse effects as throat and nasal pain occurred more frequently in COG. Conclusions. HFNC application improves oxygenation and reduces the risk of reintubation following thoracoscopic lobectomy but cannot decrease the incidence of PPC.

Evaluation of approaches for improving diesel cold flow properties

Energy Technology Data Exchange (ETDEWEB)

Sharafutdinov, Ilshat; Stratiev, Dicho; Dinkov, Rossen [Lukoil Neftochim Bourgas AD, Bourgas (Bulgaria); Bachvarov, Assen [Edinburgh Univ. (United Kingdom); Petkov, Petko [Bourgas Univ. ' ' Assen Zlatarov' ' (Bulgaria)

2012-06-15

Four heavy diesel fractions (FBP according to ASTM D-2887 of about 420 C), one lower boilingmiddle distillate fraction (FBP according to ASTM D-2887 of 310 C) and kerosene fraction (FBP according to ASTM D-2887 of 271 C) obtained from the Lukoil Neftochim Burgas (LNB) process units during the processing of Russian Export Crude Blend (REBCO) along with four heavy diesel fractions (FBP according to ASTM D-2887 of about 370 C) obtained by fractionation of four crudes: Oil Blend, REBCO, Siberian Light Crude Oil (SLCO) and CPC (Caspian Consortium Pipeline) were investigated for their cold flow properties. It was found that undercutting diesel improves cloud point (CP) and cold filter plugging point (CFPP) by 4 C/10 C cut point. Blending of kerosene improves CP and CFPP by about 2 C/10% added kerosene. The treatment with CP depressants may improve CP by about 2 C if the proper combination diesel - depressant is selected and the improvement can reach up to 6 C for a definite diesel. The treatment with CFPP depressant is much more efficient achieving an improvement of 18 C. By assuming definite fuel prices (Platts) and by applying the LNB linear programming model using Honeywell's RPMS software it was found that catalytic dewaxing is the most efficient approach for producing diesel with improved cold flowproperties if the diesel yield from the dewaxing process is higher than 90%. (orig.)

Patients with migraine with aura have increased flow mediated dilation

Directory of Open Access Journals (Sweden)

Altamura Claudia

2010-03-01

Full Text Available Abstract Background Endothelium-derived nitric oxide (NO mediates the arterial dilation following a flow increase (i.e. flow-mediated dilation, FMD, easily assessed in the brachial artery. NO is also involved in cerebral hemodynamics and it is supposed to trigger vascular changes occurring during migraine. This study aimed at investigating whether migraine patients present an altered response to NO also in the peripheral artery system. Methods We enrolled 21 migraineurs (10 with aura [MwA], 11 without aura [MwoA], and 13 controls. FMD was evaluated with ultrasound in all subjects by measuring the percentage increase of the brachial artery diameter induced by hyperaemia reactive to sustained cuff inflation around the arm above systolic pressure. FMD values were then normalized for shear stress. Results Normalized FMD values were higher in patients with MwA (28.5 10-2%.s than in controls (9.0 10-2%.s and patients with MwoA (13.7 10-2%.s (p Conclusions Migraineurs with aura present an excessive arterial response to hyperaemia, likely as an effect of an increased sensitivity to endothelium-derived nitric oxide. This phenomenon observed peripherally might reflect similar characteristics in the cerebral circulation.

Flow cytometry of duodenal intraepithelial lymphocytes improves diagnosis of celiac disease in difficult cases.

Science.gov (United States)

Valle, Julio; Morgado, José Mario T; Ruiz-Martín, Juan; Guardiola, Antonio; Lopes-Nogueras, Miriam; García-Vela, Almudena; Martín-Sacristán, Beatriz; Sánchez-Muñoz, Laura

2017-10-01

Diagnosis of celiac disease is difficult when the combined results of serology and histology are inconclusive. Studies using flow cytometry of intraepithelial lymphocytes (IELs) have found that celiac patients have increased numbers of γδ IELs, along with a decrease in CD3-CD103 + IELs. The objective of this article is to assess the role of flow cytometric analysis of IELs in the diagnosis of celiac disease in difficult cases. A total of 312 patients with suspicion of celiac disease were included in the study. Duodenal biopsy samples were used for histological assessment and for flow cytometric analysis of IELs. In 46 out of 312 cases (14.7%) the combination of serology and histology did not allow the confirmation or exclusion of celiac disease. HLA typing had been performed in 42 of these difficult cases. Taking into account HLA typing and the response to a gluten-free diet, celiac disease was excluded in 30 of these cases and confirmed in the remaining 12. Flow cytometric analysis of IELs allowed a correct diagnosis in 39 out of 42 difficult cases (92.8%) and had a sensitivity of 91.7% (95% CI: 61.5% to 99.8%) and a specificity of 93.3% (95% CI: 77.9% to 99.2%) for the diagnosis of celiac disease in this setting. Flow cytometric analysis of IELs is useful for the diagnosis of celiac disease in difficult cases.

The value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure

Directory of Open Access Journals (Sweden)

Hong-Zhuan Song

Full Text Available OBJECTIVE: To investigate the value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure. METHODS: A single-center, prospective, randomized, controlled pilot trial was conducted between January 2013 and December 2014. Sixty enrolled patients were randomized immediately after extubation into either a high-flow nasal cannula group (n=30 or an air entrainment mask group (n=30 at a fixed inspired oxygen fraction (40%. The success rate of oxygen therapy, respiratory and hemodynamic parameters and subjective discomfort (using a visual analogue scale were assessed at 24h after extubation. RESULTS: The two groups were comparable at extubation. A total of 46 patients were successfully treated including 27 patients in the high-flow nasal cannula group and 19 patients in the air entrainment mask group. Compared to the air entrainment mask group, the success rate of oxygen therapy and the partial pressure of arterial oxygen were significantly higher and the respiratory rate was lower in the high-flow nasal cannula group. In addition, less discomfort related to interface displacement and airway dryness was observed in the high-flow nasal cannula group than in the air entrainment mask group. CONCLUSIONS: At a fixed inspired oxygen fraction, the application of a high-flow nasal cannula after extubation achieves a higher success rate of oxygen therapy and less discomfort at 24h than an air entrainment mask in patients with acute respiratory failure.

Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

International Nuclear Information System (INIS)

Seeters, Tom van; Velthuis, Birgitta K.; Biessels, Geert Jan; Kappelle, L.J.; Graaf, Yolanda van der

2016-01-01

Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the relation between leptomeningeal collateral flow and clinical outcome. We included 484 patients from the Dutch acute stroke study (DUST) with a middle cerebral artery (MCA) occlusion. The determinants of poor leptomeningeal collateral flow (≤50 % collateral filling) were identified with logistic regression. We calculated the relative risk (RR) of poor leptomeningeal collateral flow in relation to poor clinical outcome (90-day modified Rankin Scale 3-6) using Poisson regression and assessed whether the determinants of leptomeningeal collateral flow affected this relation. Leptomeningeal collateral flow was poor in 142 patients (29 %). In multivariable analyses, higher admission glucose level (odds ratio (OR) 1.1 per mmol/L increase (95 % CI 1.0-1.2)), a proximal MCA occlusion (OR 1.9 (95 % CI 1.3-3.0)), and an incomplete posterior circle of Willis (OR 1.7 (95 % CI 1.1-2.6)) were independently related to poor leptomeningeal collateral flow. Poor leptomeningeal collateral flow was related to poor clinical outcome (unadjusted RR 1.7 (95 % CI 1.4-2.0)), and this relation was not affected by the determinants of leptomeningeal collateral flow. Our study shows that admission glucose level, a proximal MCA occlusion, and an incomplete ipsilateral posterior circle of Willis are determinants of leptomeningeal collateral flow that represent a combination of congenital, acquired, and acute factors. After adjustment for these determinants, leptomeningeal collateral flow remains related to clinical outcome. (orig.)

Determinants of leptomeningeal collateral flow in stroke patients with a middle cerebral artery occlusion

Energy Technology Data Exchange (ETDEWEB)

Seeters, Tom van; Velthuis, Birgitta K. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Biessels, Geert Jan; Kappelle, L.J. [University Medical Center Utrecht, Department of Neurology, Brain Center Rudolf Magnus, Utrecht (Netherlands); Graaf, Yolanda van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Collaboration: on behalf of the Dutch acute stroke study (DUST) investigators

2016-10-15

Poor leptomeningeal collateral flow is related to worse clinical outcome in acute ischemic stroke, but the factors that determine leptomeningeal collateral patency are largely unknown. We explored the determinants of leptomeningeal collateral flow and assessed their effect on the relation between leptomeningeal collateral flow and clinical outcome. We included 484 patients from the Dutch acute stroke study (DUST) with a middle cerebral artery (MCA) occlusion. The determinants of poor leptomeningeal collateral flow (≤50 % collateral filling) were identified with logistic regression. We calculated the relative risk (RR) of poor leptomeningeal collateral flow in relation to poor clinical outcome (90-day modified Rankin Scale 3-6) using Poisson regression and assessed whether the determinants of leptomeningeal collateral flow affected this relation. Leptomeningeal collateral flow was poor in 142 patients (29 %). In multivariable analyses, higher admission glucose level (odds ratio (OR) 1.1 per mmol/L increase (95 % CI 1.0-1.2)), a proximal MCA occlusion (OR 1.9 (95 % CI 1.3-3.0)), and an incomplete posterior circle of Willis (OR 1.7 (95 % CI 1.1-2.6)) were independently related to poor leptomeningeal collateral flow. Poor leptomeningeal collateral flow was related to poor clinical outcome (unadjusted RR 1.7 (95 % CI 1.4-2.0)), and this relation was not affected by the determinants of leptomeningeal collateral flow. Our study shows that admission glucose level, a proximal MCA occlusion, and an incomplete ipsilateral posterior circle of Willis are determinants of leptomeningeal collateral flow that represent a combination of congenital, acquired, and acute factors. After adjustment for these determinants, leptomeningeal collateral flow remains related to clinical outcome. (orig.)

Design optimization of axial flow hydraulic turbine runner: Part I - an improved Q3D inverse method

Science.gov (United States)

Peng, Guoyi; Cao, Shuliang; Ishizuka, Masaru; Hayama, Shinji

2002-06-01

With the aim of constructing a comprehensive design optimization procedure of axial flow hydraulic turbine, an improved quasi-three-dimensional inverse method has been proposed from the viewpoint of system and a set of rotational flow governing equations as well as a blade geometry design equation has been derived. The computation domain is firstly taken from the inlet of guide vane to the far outlet of runner blade in the inverse method and flows in different regions are solved simultaneously. So the influence of wicket gate parameters on the runner blade design can be considered and the difficulty to define the flow condition at the runner blade inlet is surmounted. As a pre-computation of initial blade design on S2m surface is newly adopted, the iteration of S1 and S2m surfaces has been reduced greatly and the convergence of inverse computation has been improved. The present model has been applied to the inverse computation of a Kaplan turbine runner. Experimental results and the direct flow analysis have proved the validation of inverse computation. Numerical investigations show that a proper enlargement of guide vane distribution diameter is advantageous to improve the performance of axial hydraulic turbine runner. Copyright

Renal blood flow and metabolism after cold ischaemia: peroperative measurements in patients with calculi

DEFF Research Database (Denmark)

Petersen, H K; Henriksen, Jens Henrik Sahl

1984-01-01

Peroperative measurements of renal blood flow (RBF), renal O2-uptake, and renal venous lactate/pyruvate (L/P) ratio were performed before and after a period of 30-71 min of hypothermic (10-15 degrees C) renal ischaemia in nine patients, undergoing surgery for renal calculi. Before ischaemia, RBF.......01) immediately after re-established perfusion and 36% (P less than 0.02) 30 min later. In one additional patient, who had a short warm ischaemia (8 min), the flow pattern was the same. As arterial pressure remained constant, the reduced RBF signifies an increased renal vascular resistance. Renal O2-uptake...... and renal venous L/P ratio were almost constant, indicating no significant anaerobic processes being involved in the flow response. None of the patients showed any signs of reactive hyperaemia. It is concluded that hypothermic renal ischaemia may be followed by an increased renal vascular resistance even...

Availability improvement of layer 2 seamless networks using OpenFlow.

Science.gov (United States)

Molina, Elias; Jacob, Eduardo; Matias, Jon; Moreira, Naiara; Astarloa, Armando

2015-01-01

The network robustness and reliability are strongly influenced by the implementation of redundancy and its ability of reacting to changes. In situations where packet loss or maximum latency requirements are critical, replication of resources and information may become the optimal technique. To this end, the IEC 62439-3 Parallel Redundancy Protocol (PRP) provides seamless recovery in layer 2 networks by delegating the redundancy management to the end-nodes. In this paper, we present a combination of the Software-Defined Networking (SDN) approach and PRP topologies to establish a higher level of redundancy and thereby, through several active paths provisioned via the OpenFlow protocol, the global reliability is increased, as well as data flows are managed efficiently. Hence, the experiments with multiple failure scenarios, which have been run over the Mininet network emulator, show the improvement in the availability and responsiveness over other traditional technologies based on a single active path.

Salivary flow rate and xerostomia in patients with type I and II diabetes mellitus.

Science.gov (United States)

Hoseini, Amineh; Mirzapour, Ali; Bijani, Ali; Shirzad, Atena

2017-09-01

Diabetes mellitus is one of the most prevalent metabolic diseases, with complications such as decreased salivary flow rate and xerostomia. This study aimed to determine the salivary flow rate and xerostomia in type I and II diabetic patients in comparison with healthy controls. This case-control study was performed on diabetic patients of a private office in Babol, Iran, between May 2015 and October 2016. This study involved two study groups (type I and II diabetes, with 40 in each group) and two control groups (control I and II, with 35 in each group) which were age- and sex-matched with the related study groups. They were all selected through simple sampling. Unstimulated whole saliva was collected through Navazesh method and the salivary flow rate was measured (ml/min). Xerostomia was evaluated via Fox's test. Moreover, the patients' data were recorded including age, sex, disease duration, type of diabetes, fasting blood glucose (FBG) and HbA1C. The obtained data were statistically analyzed by using SPSS version 17. Independent-samples t-test, Chi-square, Pearson correlation and multiple comparison post-hoc tests were employed as appropriated. psalivary flow rate in type I diabetics (0.35±0.11 ml/min) was lower than that in control I (0.50±0.07 ml/min) (p=0.01). The same difference was observed between type II diabetics (0.37±0.13 ml/min) and control II groups (0.47±0.11 ml/min) (p=0.01). No significant difference was observed in the salivary flow rate between type I and II diabetics (p=0.345). Furthermore, xerostomia was higher in type I (2.70±2.50, 1.17±1.60) and II (2.65±2.20-1.62±1.50) diabetics compared with the related control groups (p=0.01), (p=0.02). Type I, II diabetic patients revealed lower salivary flow rate and higher xerostomia compared with healthy controls. The salivary flow rate and xerostomia had inverse correlation.

Improved Diffuse Fluorescence Flow Cytometer Prototype for High Sensitivity Detection of Rare Circulating Cells In Vivo

Science.gov (United States)

Pestana, Noah Benjamin

Accurate quantification of circulating cell populations is important in many areas of pre-clinical and clinical biomedical research, for example, in the study of cancer metastasis or the immune response following tissue and organ transplants. Normally this is done "ex-vivo" by drawing and purifying a small volume of blood and then analyzing it with flow cytometry, hemocytometry or microfludic devices, but the sensitivity of these techniques are poor and the process of handling samples has been shown to affect cell viability and behavior. More recently "in vivo flow cytometry" (IVFC) techniques have been developed where fluorescently-labeled cells flowing in a small blood vessel in the ear or retina are analyzed, but the sensitivity is generally poor due to the small sampling volume. To address this, our group recently developed a method known as "Diffuse Fluorescence Flow Cytometry" (DFFC) that allows detection and counting of rare circulating cells with diffuse photons, offering extremely high single cell counting sensitivity. In this thesis, an improved DFFC prototype was designed and validated. The chief improvements were three-fold, i) improved optical collection efficiency, ii) improved detection electronics, and iii) development of a method to mitigate motion artifacts during in vivo measurements. In combination, these improvements yielded an overall instrument detection sensitivity better than 1 cell/mL in vivo, which is the most sensitive IVFC system reported to date. Second, development and validation of a low-cost microfluidic device reader for analysis of ocular fluids is described. We demonstrate that this device has equivalent or better sensitivity and accuracy compared a fluorescence microscope, but at an order-of-magnitude reduced cost with simplified operation. Future improvements to both instruments are also discussed.

Predicting changes in flow category in patients with severe aortic stenosis and preserved left ventricular ejection fraction on medical therapy.

Science.gov (United States)

Ngiam, Jinghao Nicholas; Kuntjoro, Ivandito; Tan, Benjamin Y Q; Sim, Hui-Wen; Kong, William K F; Yeo, Tiong-Cheng; Poh, Kian-Keong

2017-11-01

Controversy surrounds the prognosis and management of patients with paradoxical low-flow severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF). It was not certain if patients in a particular flow category remained in the same category as disease progressed. We investigated whether there were switches in categories and if so, their predictors. Consecutive subjects (n = 203) with isolated severe AS and paired echocardiography (>180 days apart) were studied. They were divided into 4 groups, based on their flow categories and if they progressed on subsequent echocardiography to switch or remain in the same flow category. Univariate analyses of clinical and echocardiographic parameters identified predictors of these changes in flow category. One hundred eighteen were normal flow (SVI ≥ 35 mL/m 2 ), while 85 were low flow on index echocardiography. In the patients with normal flow, 33% switched to low flow. This was associated with higher valvuloarterial impedance (Zva, P 4.77 mm Hg/mL/m 2 , AUC = 0.81 [95% CI:0.75-0.87, P < .001]). In patients with low flow, 25% switched to normal flow, which was associated with lower Zva and higher SAC and the switch was predicted by a higher initial mean transaortic pressure gradient. A significant number of patients switched flow categories in severe AS with preserved LVEF on subsequent echocardiography. Changes in flow were reflected by respective changes in Zva and SAC. Identifying echocardiographic predictors of a switch in category may guide prognostication and management of such patients. © 2017, Wiley Periodicals, Inc.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles.

Science.gov (United States)

Fogel, Mark A; Li, Christine; Wilson, Felice; Pawlowski, Tom; Nicolson, Susan C; Montenegro, Lisa M; Diaz Berenstein, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Clancy, Robert; Elci, Okan; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2015-08-01

Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3-9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was pflow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=-0.67--0.70 for all patients on room air, pflow was higher prior to BDG than in other stages. There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. NCT02135081. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Carotid Artery Stenting in a Patient With a Continuous-Flow Left Ventricular Assist Device.

Science.gov (United States)

Piazza, Michele; Squizzato, Francesco; Grego, Franco; Bottio, Tommaso; Gerosa, Gino; Antonello, Michele

2016-08-01

To demonstrate the safety and feasibility of carotid artery stenting (CAS) in a patient with a continuous-flow left ventricular assist device (LVAD). A 54-year-old woman with a LVAD was referred for a 90% stenosis of the right internal carotid artery (ICA). The patient was offered CAS, and oral anticoagulant was not discontinued in the periprocedural period. Because of absent arterial pulses, percutaneous transfemoral access was obtained under ultrasound guidance. Particular attention was paid to cannulation of the innominate artery; a 7-F guiding catheter was advanced from the descending aorta into the innominate artery under road-mapping, avoiding maneuvers in the ascending aorta where the outflow Dacron graft of the LVAD was anastomosed. To avoid cerebral flow modifications, the Angioguard RX was used as the cerebral protection device rather than other devices such as the flow reversal or flow-clamping systems. At this point, CAS was performed in a standard fashion using the 7×30-mm Precise ProRX stent. The computed tomography angiogram at 6 months showed patency of the stented right ICA. With adequate planning, CAS appears feasible in patients with a LVAD. © The Author(s) 2016.

Myocardial blood flow in patients with coronary disease while in active employment

International Nuclear Information System (INIS)

Kahn, P.; Heeger, H.; Aldor, E.; Hanuschkrankenhaus, Vienna

1975-01-01

In the course of coronary angiographies the blood flow of the right and the left coronary artery was determined by the 133 Xe lavage method in 89 patients with coronary heart disease. There was a statistically significant difference between the flow values of the LCA and RCA, while there was none between the blood flow values of blue- and white-collar workers suffering from coronary artery disease. Also a significantly better blood circulation of the right as well as of the left coronary artery was found in female employees in comparison to male employees. (orig.) [de

Integrative practices in hospitals and their impact on patient flow

NARCIS (Netherlands)

Drupsteen, J.; van der Vaart, T.; van Donk, D.P.

2013-01-01

Purpose - The aim of this paper is to investigate which integrative planning and control practices are used in hospitals and what their effects are on patient flow. Design/methodology/approach - The study is based on a three-hospital multi-case study carried out in The Netherlands. The main findings

Evaluation of Salivary Glucose, IgA and Flow Rate in Diabetic Patients: A Case-Control Study

OpenAIRE

Bakianian Vaziri, P.; Vahedi, M.; Mortazavi, H.; Abdollahzadeh, Sh.; Hajilooi, M.

2010-01-01

Objective: An association between diabetes mellitus and alterations in the oral cavity has been noted. In this study, we evaluated differences between salivary IgA, glucose and flow rate in diabetic patients compared with healthy controls. Materials and Methods: Forty patients with type 1 diabetes, 40 patients with type 2 diabetes and 40 healthy controls were selected. Whole unstimulated saliva samples were collected by the standard method and the salivary flow rate was determined. Nephelomet...

Development of a Streamlined Work Flow for Handling Patients' Genetic Testing Insurance Authorizations.

Science.gov (United States)

Uhlmann, Wendy R; Schwalm, Katie; Raymond, Victoria M

2017-08-01

Obtaining genetic testing insurance authorizations for patients is a complex, time-involved process often requiring genetic counselor (GC) and physician involvement. In an effort to mitigate this complexity and meet the increasing number of genetic testing insurance authorization requests, GCs formed a novel partnership with an industrial engineer (IE) and a patient services associate (PSA) to develop a streamlined work flow. Eight genetics clinics and five specialty clinics at the University of Michigan were surveyed to obtain benchmarking data. Tasks needed for genetic testing insurance authorization were outlined and time-saving work flow changes were introduced including 1) creation of an Excel password-protected shared database between GCs and PSAs, used for initiating insurance authorization requests, tracking and follow-up 2) instituting the PSAs sending GCs a pre-clinic email noting each patients' genetic testing insurance coverage 3) inclusion of test medical necessity documentation in the clinic visit summary note instead of writing a separate insurance letter and 4) PSAs development of a manual with insurance providers and genetic testing laboratories information. These work flow changes made it more efficient to request and track genetic testing insurance authorizations for patients, enhanced GCs and PSAs communication, and reduced tasks done by clinicians.

Evaluation of Salivary Glucose, IgA and Flow Rate in Diabetic Patients: A Case-Control Study

Directory of Open Access Journals (Sweden)

P. Bakianian Vaziri

2010-03-01

Full Text Available Objective: An association between diabetes mellitus and alterations in the oral cavity has been noted. In this study, we evaluated differences between salivary IgA, glucose and flow rate in diabetic patients compared with healthy controls.Materials and Methods: Forty patients with type 1 diabetes, 40 patients with type 2 diabetes and 40 healthy controls were selected. Whole unstimulated saliva samples were collected by the standard method and the salivary flow rate was determined. Nephelometricand Pars method were used to measure salivary IgA and salivary glucose concentrations,respectively. Statistical analysis was performed by Chi-square and t test.Results: There were no significant differences in salivary IgA and glucose concentrations between type 1 and type 2 diabetic patients and their matched control subjects (P>0.05.Salivary flow rate was significantly lower in diabetic patients (P<0.05. In addition,DMFT was higher in diabetic patients than the controls.Conclusion: Determination of salivary constituents may be useful in the description and management of oral findings in diabetic patients.

Landscape and flow metrics affecting the distribution of a federally-threatened fish: Improving management, model fit, and model transferability

Science.gov (United States)

Worthington, Thomas A.; Zhang, T.; Logue, Daniel R.; Mittelstet, Aaron R.; Brewer, Shannon K.

2016-01-01

Truncated distributions of pelagophilic fishes have been observed across the Great Plains of North America, with water use and landscape fragmentation implicated as contributing factors. Developing conservation strategies for these species is hindered by the existence of multiple competing flow regime hypotheses related to species persistence. Our primary study objective was to compare the predicted distributions of one pelagophil, the Arkansas River Shiner Notropis girardi, constructed using different flow regime metrics. Further, we investigated different approaches for improving temporal transferability of the species distribution model (SDM). We compared four hypotheses: mean annual flow (a baseline), the 75th percentile of daily flow, the number of zero-flow days, and the number of days above 55th percentile flows, to examine the relative importance of flows during the spawning period. Building on an earlier SDM, we added covariates that quantified wells in each catchment, point source discharges, and non-native species presence to a structured variable framework. We assessed the effects on model transferability and fit by reducing multicollinearity using Spearman’s rank correlations, variance inflation factors, and principal component analysis, as well as altering the regularization coefficient (β) within MaxEnt. The 75th percentile of daily flow was the most important flow metric related to structuring the species distribution. The number of wells and point source discharges were also highly ranked. At the default level of β, model transferability was improved using all methods to reduce collinearity; however, at higher levels of β, the correlation method performed best. Using β = 5 provided the best model transferability, while retaining the majority of variables that contributed 95% to the model. This study provides a workflow for improving model transferability and also presents water-management options that may be considered to improve the

Improving medication adherence in patients with hypertension

DEFF Research Database (Denmark)

Hedegaard, Ulla; Kjeldsen, Lene Juel; Pottegård, Anton

2015-01-01

BACKGROUND: and Purpose: In patients with hypertension, medication adherence is often suboptimal, thereby increasing the risk of ischemic heart disease and stroke. In a randomized trial, we investigated the effectiveness of a multifaceted pharmacist intervention in a hospital setting to improve...... medication adherence in hypertensive patients. Motivational interviewing was a key element of the intervention. METHODS: Patients (N=532) were recruited from 3 hospital outpatient clinics and randomized to usual care or a 6-month pharmacist intervention comprising collaborative care, medication review...... for persistence, blood pressure or hospital admission. CONCLUSIONS: A multifaceted pharmacist intervention in a hospital setting led to a sustained improvement in medication adherence for patients with hypertension. The intervention had no significant impact on blood pressure and secondary clinical outcomes....

Interim Columbia and Snake rivers flow improvement measures for salmon: Final Supplemental Environmental Impact Statement (SEIS)

Energy Technology Data Exchange (ETDEWEB)

1993-03-01

Public comments are sought on this final SEIS, which supplements the 1992 Columbia River Salmon Flow Measures Options Analysis (OA)/Environmental Impact Statement (EIS). The Corps of Engineers, in cooperation with the Bonneville Power Administration and the Bureau of Reclamation proposes five alternatives to improve flows of water in the lower Columbia-Snake rivers in 1993 and future years to assist the migration of juvenile and adult anadromous fish past eight hydropower dams. These are: (1) Without Project (no action) Alternative, (2) the 1992 Operation, (3) the 1992 Operation with Libby/Hungry Horse Sensitivity, (4) a Modified 1992 Operation with Improvements to Salmon Flows from Dworshak, and (5) a Modified 1992 Operation with Upper Snake Sensitivity. Alternative 4, Modified 1992 Operations, has been identified as the preferred alternative.

Cerebrospinal fluid flow and production in patients with normal pressure hydrocephalus studied by MRI

DEFF Research Database (Denmark)

Gideon, P; Ståhlberg, F; Thomsen, C

1994-01-01

An interleaved velocity-sensitised fast low-angle shot pulse sequence was used to study cerebrospinal fluid (CSF) flow in the cerebral aqueduct, and supratentorial CSF production in 9 patients with normal pressure hydrocephalus (NPH) and 9 healthy volunteers. The peak aqueduct CSF flow, both caudal...

Cerebral blood flow response to hypoglycemia is altered in patients with type 1 diabetes and impaired awareness of hypoglycemia.

Science.gov (United States)

Wiegers, Evita C; Becker, Kirsten M; Rooijackers, Hanne M; von Samson-Himmelstjerna, Federico C; Tack, Cees J; Heerschap, Arend; de Galan, Bastiaan E; van der Graaf, Marinette

2017-06-01

It is unclear whether cerebral blood flow responses to hypoglycemia are altered in people with type 1 diabetes and impaired awareness of hypoglycemia. The aim of this study was to investigate the effect of hypoglycemia on both global and regional cerebral blood flow in type 1 diabetes patients with impaired awareness of hypoglycemia, type 1 diabetes patients with normal awareness of hypoglycemia and healthy controls ( n = 7 per group). The subjects underwent a hyperinsulinemic euglycemic-hypoglycemic glucose clamp in a 3 T MR system. Global and regional changes in cerebral blood flow were determined by arterial spin labeling magnetic resonance imaging, at the end of both glycemic phases. Hypoglycemia generated typical symptoms in patients with type 1 diabetes and normal awareness of hypoglycemia and healthy controls, but not in patients with impaired awareness of hypoglycemia. Conversely, hypoglycemia increased global cerebral blood flow in patients with impaired awareness of hypoglycemia, which was not observed in the other two groups. Regionally, hypoglycemia caused a redistribution of cerebral blood flow towards the thalamus of both patients with normal awareness of hypoglycemia and healthy controls, consistent with activation of brain regions associated with the autonomic response to hypoglycemia. No such redistribution was found in the patients with impaired awareness of hypoglycemia. An increase in global cerebral blood flow may enhance nutrient supply to the brain, hence suppressing symptomatic awareness of hypoglycemia. Altogether these results suggest that changes in cerebral blood flow during hypoglycemia contribute to impaired awareness of hypoglycemia.

Effectiveness of Electrostimulation on Whole Salivary Flow Among Patients with Type 2 Diabetes Mellitus.

Science.gov (United States)

Dyasnoor, Sujatha; Kamath, Shwetha; Khader, Nishat Fatima Abdul

2017-01-01

Xerostomia and hyposalivation are associated with diabetes. Research is sparse regarding electrostimulation as a mainstream therapy for salivary gland hypofunction. To clinically evaluate the effectiveness of transcutaneous electric nerve stimulation (TENS) therapy in stimulating whole salivary flow among patients with xerostomia and hyposalivation caused by diabetes mellitus. Forty patients between age 30 to 75 years with diabetes mellitus categorized as controlled or uncontrolled who had subjective symptoms of xerostomia and an objective sign of hyposalivation were included in a prospective study. Unstimulated saliva through the "low forced spitting" method and stimulated saliva collection using TENS were assessed and compared. Longer-term effects of TENS application were evaluated by recalling the patient 24 hours later. A statistically significant increase in stimulated whole saliva after TENS application in continuous mode (p diabetes. Burst mode inferred a statistically significant decrease in salivary flow (p diabetes with xerostomia and hyposalivation, TENS was highly effective in stimulating whole salivary flow.

How benchmarking can improve patient nutrition.

Science.gov (United States)

Ellis, Jane

Benchmarking is a tool that originated in business to enable organisations to compare their services with industry-wide best practice. Early last year the Department of Health published The Essence of Care, a benchmarking toolkit adapted for use in health care. It focuses on eight elements of care that are crucial to patients' experiences. Nurses and other health care professionals at a London NHS trust have begun a trust-wide benchmarking project. The aim is to improve patients' experiences of health care by sharing and comparing information, and by identifying examples of good practice and areas for improvement. The project began with two of the eight elements of The Essence of Care, with the intention of covering the rest later. This article describes the benchmarking process for nutrition and some of the consequent improvements in care.

Comparison of the effectiveness of high flow nasal oxygen cannula vs. standard non-rebreather oxygen face mask in post-extubation intensive care unit patients.

Science.gov (United States)

Brotfain, Evgeni; Zlotnik, Alexander; Schwartz, Andrei; Frenkel, Amit; Koyfman, Leonid; Gruenbaum, Shaun E; Klein, Moti

2014-11-01

Optimal oxygen supply is the cornerstone of the management of critically ill patients after extubation, especially in patients at high risk for extubation failure. In recent years, high flow oxygen system devices have offered an appropriate alternative to standard oxygen therapy devices such as conventional face masks and nasal prongs. To assess the clinical effects of high flow nasal cannula (HFNC) compared with standard oxygen face masks in Intensive Care Unit (ICU) patients after extubation. We retrospectively analyzed 67 consecutive ventilated critical care patients in the ICU over a period of 1 year. The patients were allocated to two treatment groups: HFNC (34 patients, group 1) and non-rebreathing oxygen face mask (NRB) (33 patients, group 2). Vital respiratory and hemodynamic parameters were assessed prior to extubation and 6 hours after extubation. The primary clinical outcomes measured were improvement in oxygenation, ventilation-free days, re-intubation, ICU length of stay, and mortality. The two groups demonstrated similar hemodynamic patterns before and after extubation. The respiratory rate was slightly elevated in both groups after extubation with no differences observed between groups. There were no statistically significant clinical differences in PaCO2. However, the use of HFNC resulted in improved PaO2/FiO2 post-extubation (P < 0.05). There were more ventilator-free days in the HFNC group (P< 0.05) and fewer patients required reintubation (1 vs. 6). There were no differences in ICU length of stay or mortality. This study demonstrated better oxygenation for patients treated with HFNC compared with NRB after extubation. HFNC may be more effective than standard oxygen supply devices for oxygenation in the post-extubation period.

A study of complications affecting surgery performance: an ISM-based roadmap to patient flow.

Science.gov (United States)

Dev, Navin K; Shankar, Ravi; Arvind, Kamal

2013-01-01

The aim of this study is to highlight the value of the success rate performance of a surgery while planning patient flow within a supply chain of a health care organization/hospital. The paper has considered one of the common surgeries, cataract, and the complications that subsequently result from this surgery. The study employs interpretive structural modeling (ISM) approach to draw a roadmap to study various complications causing cataract that subsequently help in planning and coordination of patient flow. The study finds that there is a hierarchy of causes and certain complications, the persistence of which gives a higher success rate performance in cataract surgery as compared to others. The paper provides leverage to the decision maker while organizing the patient flow depending upon the information of hierarchy of complication of a disease, and accordingly ensures the availability of resources to the patient. The study is of value in identifying the degree of complications from cataract surgery. Given the degree of complication, the patient logistics can be planned myopically in a health care organization which largely depends upon the degree of success rate. The paper attempts to suggest that the hierarchy obtained through ISM can be implemented in the modules of an enterprise resource planning (ERP) set up.

Patient-Centered Prescription Model to improve therapeutic adherence in patients with multimorbidity

Directory of Open Access Journals (Sweden)

Javier González-Bueno

2018-05-01

Full Text Available To date, interventions to improve medication adherence in patients with multimorbidity have shown modest and inconsistent efficacy among available studies. Thereby, we should define new approaches aimed at improving medication adherence tailored to effective prescribing, with a multidisciplinary approach and patient-centered. In this regard, the Patient-Centered Prescription Model has shown its usefulness on improving appropriateness of drug treatments in patients with clinical complexity. For that, this strategy addresses the following four steps: 1 Patient-Centered assessment; 2 Diagnosis-Centered assessment; 3 Medication-Centered assessment; and 4 Therapeutic Plan. We propose through a clinical case an adaptation of the Patient-Centered Prescription Model to enhance both appropriateness and medication adherence in patients with multimorbidity. To this end, we have included on its first step the Spanish version of a cross-culturally adapted scale for the multidimensional assessment of medication adherence. Furthermore, we suggest a set of interventions to be applied in the three remaining steps of the model. These interventions were firstly identified by an overview of systematic reviews and then selected by a panel of experts based on Delphi methodology. All of these elements have been considered appropriate in patients with multimorbidity according to three criteria: strength of their supporting evidence, usefulness in the target population and feasibility of implementation in clinical practice. The proposed approach intends to lay the foundations for an innovative way in tackling medication adherence in patients with multimorbidity.

Improving Patient Satisfaction with Waiting Time

Science.gov (United States)

Eilers, Gayleen M.

2004-01-01

Waiting times are a significant component of patient satisfaction. A patient satisfaction survey performed in the author's health center showed that students rated waiting time lowest of the listed categories--A ratings of 58% overall, 63% for scheduled appointments, and 41% for the walk-in clinic. The center used a quality improvement process and…

Investigating the use of patient involvement and patient experience in quality improvement in Norway

DEFF Research Database (Denmark)

Wiig, Siri; Storm, Marianne; Aase, Karina

2013-01-01

-fold: 1) to describe and analyze how governmental organizations expect acute hospitals to incorporate patient involvement and patient experiences into their quality improvement (QI) efforts and 2) to analyze how patient involvement and patient experiences are used by hospitals to try to improve...... the quality of care they provide. METHODS: This multi-level case study combines analysis of national policy documents and regulations at the macro level with semi-structured interviews and non-participant observation of key meetings and shadowing of staff at the meso and micro levels in two purposively...... in hospitals. The expectations span from systematic collection of patients' and family members' experiences for the purpose of improving service quality through establishing patient-oriented arenas for ongoing collaboration with staff to the support of individual involvement in decision making. However...

Automated structure and flow measurement - a promising tool in nailfold capillaroscopy.

Science.gov (United States)

Berks, Michael; Dinsdale, Graham; Murray, Andrea; Moore, Tonia; Manning, Joanne; Taylor, Chris; Herrick, Ariane L

2018-07-01

Despite increasing interest in nailfold capillaroscopy, objective measures of capillary structure and blood flow have been little studied. We aimed to test the hypothesis that structural measurements, capillary flow, and a combined measure have the predictive power to separate patients with systemic sclerosis (SSc) from those with primary Raynaud's phenomenon (PRP) and healthy controls (HC). 50 patients with SSc, 12 with PRP, and 50 HC were imaged using a novel capillaroscopy system that generates high-quality nailfold images and provides fully-automated measurements of capillary structure and blood flow (capillary density, mean width, maximum width, shape score, derangement and mean flow velocity). Population statistics summarise the differences between the three groups. Areas under ROC curves (A Z ) were used to measure classification accuracy when assigning individuals to SSc and HC/PRP groups. Statistically significant differences in group means were found between patients with SSc and both HC and patients with PRP, for all measurements, e.g. mean width (μm) ± SE: 15.0 ± 0.71, 12.7 ± 0.74 and 11.8 ± 0.23 for SSc, PRP and HC respectively. Combining the five structural measurements gave better classification (A Z  = 0.919 ± 0.026) than the best single measurement (mean width, A Z  = 0.874 ± 0.043), whilst adding flow further improved classification (A Z  = 0.930 ± 0.024). Structural and blood flow measurements are both able to distinguish patients with SSc from those with PRP/HC. Importantly, these hold promise as clinical trial outcome measures for treatments aimed at improving finger blood flow or microvascular remodelling. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Beyond consent--improving understanding in surgical patients.

LENUS (Irish Health Repository)

Mulsow, Jürgen J W

2012-01-01

Little is known of the actual understanding that underlies patient choices with regard to their surgical treatment. This review explores current knowledge of patient understanding and techniques that may be used to improve this understanding.

Relationship between segmental thallium-201 uptake and regional myocardial blood flow in patients with coronary artery disease

International Nuclear Information System (INIS)

Nichols, A.B.; Weiss, M.B.; Sciacca, R.R.; Cannon, P.J.; Blood, D.K.

1983-01-01

The relationship between the spatial distribution of thallium-201 in myocardial perfusion scintigrams and the distribution of left ventricular regional myocardial blood flow was examined in 25 patients undergoing coronary arteriography. Thallium-201 myocardial scintigrams were obtained after symptom-limited exercise and after a 4 hr delay. Regional myocardial blood flow was measured by the xenon-133 clearance method in patients at rest and during rapid atrial pacing to a double product comparable with that achieved during exercise stress testing. Patterns of regional thallium-201 activity and regional myocardial blood flow, recorded in similar left anterior oblique projections, were compared for left ventricular segments supplied by the left anterior descending (LAD) and left circumflex (CIRC) arteries. In 11 patients without significant lesions of the left coronary artery (group 1), thallium-201 was homogeneously distributed in the LAD and CIRC distributions in scintigrams taken during peak exercise; these scintigrams correspond to homogeneous regional myocardial blood flow in the LAD and CIRC regions during pacing-induced stress. In 14 patients with significant lesions of the left coronary artery (group 2), ratios of regional thallium-201 activity in the LAD and CIRC distributions of exercise scintigrams correlated well (r . .84) with ratios of regional myocardial blood flow measured during rapid pacing. Background subtraction altered the relationship between relative thallium-201 uptake and regional myocardial blood flow, causing overestimation of the magnitude of flow reduction on exercise scintigrams

Effect of Metoclopramide on Portal Blood Flow in Patients with Liver Cirrhosis: Evaluation by the Pulsed Doppler System

International Nuclear Information System (INIS)

Baik, Soon Koo; Lee, Yong Gyu; Hong, Sa Joon; Lee, Seong Wu; Lee, Dong Ki; Kwong, Sang Ok

1994-01-01

Metoclopramide is known to lower the intravariceal flow by raising the lower esophageal sphincter pressure and consequently decreases the portal blood flow. So we designed this study to assess the effect of metoclopramide on portal blood flow in cirrhotic patients using pulsed Doppler system. By using pulsed Doppler ultrasound, portal blood velocity, diameter of the portal vein, portal blood flow, blood pressure and pulse rate were measured at 15, 30 and 60 minutes after administration of 20mg metoclopramide in 16cirrhotic patients and compared with the basal values. In order 10 cirrhotic patients, normal saline was administrated, and the above mentioned parameters were measured. Wothin 15 minutes after intravenous administration of 20mg metoclopramide, portal blood velocity and portal blood flow decreased significantly, from 12.45+2.64 to 11.80+2.55cm/sec and from 1006.3+407.1 to 974.4+414.7ml/min, respectively(P<0.05). In placebo group,there was no significant change in measured parameters after administration of normal saline. These results support the hypothesis that metoclopramide significantly decreases the portal blood flow transiently in cirrhotic patients with portal hypertension

Improving patients' and staff's experiences of acute care.

Science.gov (United States)

Chaplin, Rob; Crawshaw, Jacob; Hood, Chloe

2015-03-01

The aim of this audit was to assess the effect of the Quality Mark programme on the quality of acute care received by older patients by comparing the experiences of staff and older adults before and after the programme. Data from 31 wards in 12 acute hospitals were collected over two stages. Patients and staff completed questionnaires on the perceived quality of care on the ward. Patients rated improved experiences of nutrition, staff availability and dignity. Staff received an increase in training and reported better access to support, increased time and skill to deliver care and improved morale, leadership and teamwork. Problems remained with ward comfort and mealtimes. Overall, results indicated an improvement in ratings of care quality in most domains during Quality Mark data collection. Further audits need to explore ways of improving ward comfort and mealtime experience.

Prediction of effectiveness of shunting in patients with normal pressure hydrocephalus by cerebral blood flow measurement and computed tomography cisternography

Energy Technology Data Exchange (ETDEWEB)

Chang, Chia-Cheng; Kuwana, Nobumasa; Ito, Susumu; Ikegami, Tadashi [Yokohama Minami Kyosai Hospital (Japan)

1999-11-01

Measurement of cerebral blood flow (CBF) and computed tomography (CT) cisternography were performed in 37 patients with a tentative diagnosis of normal pressure hydrocephalus (NPH) to predict their surgical outcome. The mean CBF of the whole brain was measured quantitatively by single photon emission computed tomography with technetium-99m-hexamethylpropylene amine oxime before surgery. The results of CT cisternography were classified into four patients: type I, no ventricular stasis at 24 hours; type II, no ventricular stasis with delayed clearance of cerebral blush; type III, persistent ventricular stasis with prominent cerebral blush; type IV, persistent ventricular stasis with diminished cerebral blush and/or asymmetrical filling of the sylvian fissures. The mean CBF was significantly lower than that of age-matched controls (p<0.005). Patients with a favorable outcome had a significantly higher mean CBF than patients with an unfavorable outcome (p<0.005). Patients with the type I pattern did not respond to shunting. Some patients with type II and III patterns responded to shunting but improvement was unsatisfactory. Patients with type IV pattern responded well to shunting, and those with a mean CBF of 35 ml/100 g/min or over achieved a favorable outcome. The combination of CBF measurement and CT cisternography can improve the prediction of surgical outcome in patients with suspected NPH. (author)

Prediction of effectiveness of shunting in patients with normal pressure hydrocephalus by cerebral blood flow measurement and computed tomography cisternography

International Nuclear Information System (INIS)

Chang, Chia-Cheng; Kuwana, Nobumasa; Ito, Susumu; Ikegami, Tadashi

1999-01-01

Measurement of cerebral blood flow (CBF) and computed tomography (CT) cisternography were performed in 37 patients with a tentative diagnosis of normal pressure hydrocephalus (NPH) to predict their surgical outcome. The mean CBF of the whole brain was measured quantitatively by single photon emission computed tomography with technetium-99m-hexamethylpropylene amine oxime before surgery. The results of CT cisternography were classified into four patients: type I, no ventricular stasis at 24 hours; type II, no ventricular stasis with delayed clearance of cerebral blush; type III, persistent ventricular stasis with prominent cerebral blush; type IV, persistent ventricular stasis with diminished cerebral blush and/or asymmetrical filling of the sylvian fissures. The mean CBF was significantly lower than that of age-matched controls (p<0.005). Patients with a favorable outcome had a significantly higher mean CBF than patients with an unfavorable outcome (p<0.005). Patients with the type I pattern did not respond to shunting. Some patients with type II and III patterns responded to shunting but improvement was unsatisfactory. Patients with type IV pattern responded well to shunting, and those with a mean CBF of 35 ml/100 g/min or over achieved a favorable outcome. The combination of CBF measurement and CT cisternography can improve the prediction of surgical outcome in patients with suspected NPH. (author)

Diurnal variations in lower leg subcutaneous blood flow rate in patients with chronic venous leg ulcers

DEFF Research Database (Denmark)

Sindrup, J H; Kastrup, J; Kristensen, J K

1991-01-01

The blood flow rate in subcutaneous adipose tissue was measured on the lower legs of 11 patients with chronic lower-leg venous insufficiency and ulceration and in eight age-matched control subjects for 12-20 h, under ambulatory conditions, using the 133Xe wash-out technique with portable Cadmium...... telluride (CdTe(Cl)) detectors. In both groups, the change from an upright to a supine position at the beginning of the night period elicited an instantaneous increment in the blood flow rate of 30-40% with a decrease in the central and local postural sympathetic vasoconstrictor activity. After...... approximately 1 h of sleep, a considerable increase in blood flow rate was seen in both patient and control groups which persisted for nearly 100 min. In the patient group, the mean increase was 137% compared to a mean increase of 68% in the control group (P less than 0.01). The blood flow then returned...

Severe aortic stenosis patients with preserved ejection fraction according to flow and gradient classification: Prevalence and outcomes.

Science.gov (United States)

González Gómez, Ariana; Fernández-Golfín, Covadonga; Monteagudo, Juan Manuel; Izurieta, Carlos; Hinojar, Rocío; García, Ana; Casas, Eduardo; Jiménez-Nacher, José Julio; Moya, José Luis; Ruiz, Soledad; Zamorano, José Luis

2017-12-01

Clinicians often encounter patients with apparently discordant echocardiographic findings, severe aortic stenosis (SAS) defined by aortic valve area (AVA) despite a low mean gradient. A new classification according to flow state and pressure gradient has been proposed. We sought to assess the prevalence, characteristics and outcomes of patients with asymptomatic SAS with preserved left-ventricular ejection fraction (LVEF) according to flow and gradient. In total 442 patients with SAS (AVAigradient (≥ or Gradient (LF/LG): 21.3%(n=94); Normal Flow/Low Gradient (NF/LG): 32.1%(n=142); Low Flow/High Gradient (LF/HG): 6.8%(n=30); Normal Flow/High Gradient (NF/HG): 39,8%(n=176). Mean follow-up time was 20.5months (SD=10.3). Primary combined endpoint was cardiovascular mortality and hospital admission for SAS related symptom, secondary endpoint was aortic valve replacement (AVR), comparing HG group to LF/LG group. During follow-up 17 (18%) of LF/LG patients and 21 (10.2%) of HG patients met the primary endpoint. A lower free of event survival (cardiovascular mortality and hospital admission) was observed in patients with LF/LG AS (Breslow, p=0.002). Significant differences were noted between groups with a lower AVR free survival in the LF/LG group compared to HG groups (Breslow, p=0.002). Our study confirms the high prevalence and worse prognosis of LF/LG SAS. Clinicians must be aware of this entity to ensure appropriate patient management. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

CD4+ LYMPHOCYTES IMPROVE VENOUS BLOOD FLOW IN EXPERIMENTAL ARTERIOVENOUS FISTULAE

Science.gov (United States)

Duque, Juan C.; Martinez, Laisel; Mesa, Annia; Wei, Yuntao; Tabbara, Marwan; Salman, Loay H.; Vazquez-Padron, Roberto I.

2015-01-01

Background The role of immune cells in arteriovenous fistulae (AVF) maturation is poorly understood and has received, until quite recently, little attention. This study examines the role of T lymphocytes in AVF vascular remodeling. Methods Experimental fistulae were created in athymic rnu nude rats lacking mature T lymphocytes and euthymic control animals by anastomosing the left superior epigastric vein to the nearby femoral artery. Blood flow rates, wall morphology and histological changes were assessed in AVF 21 days after creation. The effect of CD4+ lymphocytes on AVF maturation in athymic animals was analyzed by adoptive transfer of cells after fistula creation. Results The absence of T lymphocytes compromised blood flow in experimental fistulae. Histopathological inspection of AVF from athymic rats revealed that T cell immunodeficiency negatively affected venous vascular remodeling, as evidenced by a reduced lumen, a thick muscular layer and a low number of inflammatory cells compared to control animals. Adoptive transfer of CD4+ lymphocytes from euthymic rats into athymic animals before and after fistula creation improved blood flow and reduced intima-media thickness. Conclusion These results point at the protective role of CD4+ lymphocytes in the remodeling of the AVF vascular wall. PMID:25999254

Improving the spatial representation of basin hydrology and flow processes in the SWAT model

OpenAIRE

Rathjens, Hendrik

2014-01-01

This dissertation aims at improving the spatial representation of basin hydrology and flow processes in the SWAT model. Die vorliegende Dissertation stellt die methodischen Grundlage zur räumlich differenzierten Modellierung mit dem Modell SWAT dar.

Quality Improvement Project to Improve Patient Satisfaction With Pain Management: Using Human-Centered Design.

Science.gov (United States)

Trail-Mahan, Tracy; Heisler, Scott; Katica, Mary

2016-01-01

In this quality improvement project, our health system developed a comprehensive, patient-centered approach to improving inpatient pain management and assessed its impact on patient satisfaction across 21 medical centers. Using human-centered design principles, a bundle of 6 individual and team nursing practices was developed. Patient satisfaction with pain management, as measured by the Hospital Consumer Assessment of Healthcare Providers and Systems pain composite score, increased from the 25th to just under the 75th national percentile.

[Does simulator-based team training improve patient safety?].

Science.gov (United States)

Trentzsch, H; Urban, B; Sandmeyer, B; Hammer, T; Strohm, P C; Lazarovici, M

2013-10-01

Patient safety became paramount in medicine as well as in emergency medicine after it was recognized that preventable, adverse events significantly contributed to morbidity and mortality during hospital stay. The underlying errors cannot usually be explained by medical technical inadequacies only but are more due to difficulties in the transition of theoretical knowledge into tasks under the conditions of clinical reality. Crew Resource Management and Human Factors which determine safety and efficiency of humans in complex situations are suitable to control such sources of error. Simulation significantly improved safety in high reliability organizations, such as the aerospace industry.Thus, simulator-based team training has also been proposed for medical areas. As such training is consuming in cost, time and human resources, the question of the cost-benefit ratio obviously arises. This review outlines the effects of simulator-based team training on patient safety. Such course formats are not only capable of creating awareness and improvements in safety culture but also improve technical team performance and emphasize team performance as a clinical competence. A few studies even indicated improvement of patient-centered outcome, such as a reduced rate of adverse events but further studies are required in this respect. In summary, simulator-based team training should be accepted as a suitable strategy to improve patient safety.

Aortopulmonary collateral flow quantification by MR at rest and during continuous submaximal exercise in patients with total cavopulmonary connection.

Science.gov (United States)

Mkrtchyan, Naira; Frank, Yvonne; Steinlechner, Eva; Calavrezos, Lenika; Meierhofer, Christian; Hager, Alfred; Martinoff, Stefan; Ewert, Peter; Stern, Heiko

2017-11-06

Aortopulmonary collateral flow is considered to have significant impact on the outcome of patients with single ventricle circulation and total cavopulmonary connection (TCPC). There is little information on collateral flow during exercise. To quantify aortopulmonary collateral flow at rest and during continuous submaximal exercise in clinical patients doing well with TCPC. Prospective, case controlled. Thirteen patients with TCPC (17 (11-37) years) and 13 age and sex-matched healthy controls (18 (11-38) years). 1.5T; free breathing; phase sensitive gradient echo sequence. Blood flow in the ascending and descending aorta and superior vena cava were measured at rest and during continuous submaximal physical exercise in patients and controls. Systemic blood flow (Q s ) was assumed to be represented by the sum of flow in the superior caval vein (Q svc ) and the descending aorta (Q AoD ) at the diaphragm level. Aortopulmonary collateral flow (Q coll ) was calculated by subtracting Q s from flow in the ascending aorta (Q AoA ). Mann-Whitney U-test and Wilcoxon test for comparison between groups and between rest and exercise. Absolute collateral flow in TCPC patients at rest was 0.4 l/min/m 2 (-0.1-1.2), corresponding to 14% (-2-42) of Q s . Collateral flow did not change during exercise (difference -0.01 (-0.7-1.0) l/min/m 2 , P = 0.97). TCPC patients had significantly lower Q s at rest (2.5 (1.6-4.1) vs. 3.5 (2.6-4.8) l/min/m 2 , P = 0.001) and during submaximal exercise (3.2 (2.0-6.0) vs. 4.8 (3.3-6.9) l/min/m 2 , P = 0.001), compared to healthy controls. The increase in Q s with exercise was also significantly lower in patients than in healthy controls (median 0.6 vs. 1.2 l/min/m 2 , P collateral flow at rest (14% of Q s ) compared to healthy controls, which does not change during submaximal exercise. 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

Effects of oral health care on salivary flow rate in patients with type 2 diabetes: preliminary study.

Science.gov (United States)

Ibayashi, Haruhisa; Nishiyama, Tomohiro; Tanaka, Masayuki; Pham, Truong-Minh; Yano, Junko; Sakai, Kazuyo; Kobayashi, Atsushi; Yakura, Naonori; Matsuda, Shinya

2009-07-01

The purpose of this study is to evaluate the effects of the authors' oral health care program on the stimulated whole salivary flow rate and buffer capacity before and after a 6-month intervention. The authors conducted the intervention study among 25 participants with diabetes. The salivary flow rate and buffer capacity were evaluated before and after this intervention. Overall, the results showed a significant increase in salivary flow rate and no significant change in buffer capacity. Also, it was likely that salivary flow rate significantly increased among patients with more than 20 remaining teeth and patients with well-controlled diabetes. The findings suggest that this program for type 2 diabetes led to an increase in the stimulated whole salivary flow rate.

Brain blood flow studies with single photon emission computed tomography in patients with plateau waves

International Nuclear Information System (INIS)

Hayashi, Minoru; Kobayashi, Hidenori; Kawano, Hirokazu; Handa, Yuji; Noguchi, Yoshiyuki; Shirasaki, Naoki; Hirose, Satoshi

1986-01-01

The authors studied brain blood flow with single photon emission computed tomography (SPECT) in two patients with plateau waves. The intracranial pressure and blood pressure were also monitored continuously in these patients. They included one patient with brain-tumor (rt. sphenoid ridge meningioma) and another with hydrocephalus after subarachnoid hemorrhage due to rupture of lt. internal carotid aneurysm. The intracranial pressure was monitored through an indwelling ventricular catheter attached to a pressure transducer. The blood pressure was recorded through an intraarterial catheter placed in the dorsalis pedis artery. Brain blood flow was studied with Headtome SET-011 (manufactured by Shimazu Co., Ltd.). For this flow measurement study, an intravenous injection of Xenon-133 of about 30 mCi was given via an antecubital vein. The position of the slice for the SPECT was selected so as to obtain information not only from the cerebral hemisphere but also from the brain stem : a cross section 25 deg over the orbito-meatal line, passing through the inferior aspect of the frontal horn, the basal ganglia, the lower recessus of the third ventricle and the brain stem. The results indicated that, in the cerebral hemisphere, plateau waves were accompanied by a decrease in blood flow, whereas, in the brain stem, the blood flow showed little change during plateau waves as compared with the interval phase between two plateau waves. These observations may explain why there is no rise in the blood pressure and why patients are often alert during plateau waves. (author)

Multiplexed lateral flow biosensors: Technological advances for radically improving point-of-care diagnoses.

Science.gov (United States)

Li, Jia; Macdonald, Joanne

2016-09-15

Lateral flow biosensors are a leading technology in point-of-care diagnostics due to their simplicity, rapidness and low cost. Their primacy in this arena continues through technological breakthroughs such as multiplexing: the detection of more than one biomarker in a single assay. Multiplexing capacity is critical for improving diagnostic efficiency, enhancing the diagnostic precision for specific diseases and reducing diagnostic cost. Here we review, for the first time, the various types and strategies employed for creating multiplexed lateral flow biosensors. These are classified into four main categories in terms of specific application or multiplexing level, namely linear, parameter, spatial and conceptual. We describe the practical applications and implications for each approach and compare their advantages and disadvantages. Importantly, multiplexing is still subject to limitations of the traditional lateral flow biosensor, such as sensitivity and specificity. However, by pushing the limitations of the traditional medium into the multiplex arena, several technological breakthroughs are emerging with novel solutions that further expand the utility of lateral flow biosensing for point-of-care applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Cerebral blood flow is reduced in patients with sepsis syndrome

International Nuclear Information System (INIS)

Bowton, D.L.; Bertels, N.H.; Prough, D.S.; Stump, D.A.

1989-01-01

The relationship between sepsis-induced CNS dysfunction and changes in brain blood flow remains unknown, and animal studies examining the influence of sepsis on cerebral blood flow (CBF) do not satisfactorily address that relationship. We measured CBF and cerebrovascular reactivity to CO 2 in nine patients with sepsis syndrome using the 133 Xe clearance technique. Mean CBF was 29.6 +/- 15.8 (SD) ml/100 g.min, significantly lower than the normal age-matched value in this laboratory of 44.9 +/- 6.2 ml/100 g.min (p less than .02). This depression did not correlate with changes in mean arterial pressure. Despite the reduction in CBF, the specific reactivity of the cerebral vasculature to changes in CO 2 was normal, 1.3 +/- 0.9 ml/100 g.min/mm Hg. Brain blood flow is reduced in septic humans; the contribution of this reduction to the metabolic and functional changes observed in sepsis requires further study

The relationship of flow velocities to vessel diameters differs between extracranial carotid and vertebral arteries of stroke patients.

Science.gov (United States)

Owolabi, Mayowa O; Agunloye, Atinuke M; Ogunniyi, Adesola

2014-01-01

Chronic changes in flow rate through arteries produce adjustment of arterial diameters. We compared the relationship between flow velocity and diameter in the carotid and in the vertebral arteries of stroke patients. Using triplex ultrasonography, the internal diameter and flow velocities of the common carotid, internal carotid, and vertebral arteries of 176 consecutive stroke patients were measured. Correlations were examined with Pearson's statistics at an alpha level of 0.05. Mean age of the patients was 59.3 ± 12 years, and 66% had cerebral infarcts. Diameter and blood flow velocities showed significant negative correlations (-0.115 ≥ r ≥ -0.382) in the carotid arteries on both sides, but positive correlations (0.211 ≤ r ≤ 0.320) in the vertebral arteries, even after controlling for age, gender, and blood pressure. Our study demonstrated different diameter/flow relationships in the carotid and the vertebral arteries of stroke patients, which may suggest pathologic changes in the adaptive processes governing vessel diameter and growth, especially in the carotid arteries. Copyright © 2013 Wiley Periodicals, Inc.

Improving patient satisfaction through physician education, feedback, and incentives.

Science.gov (United States)

Banka, Gaurav; Edgington, Sarah; Kyulo, Namgyal; Padilla, Tony; Mosley, Virgie; Afsarmanesh, Nasim; Fonarow, Gregg C; Ong, Michael K

2015-08-01

Patient satisfaction has been associated with improved outcomes and become a focus of reimbursement. Evaluate an intervention to improve patient satisfaction. Nonrandomized, pre-post study that took place from 2011 to 2012. Large tertiary academic medical center. Internal medicine (IM) resident physicians, non-IM resident physicians, and adult patients of the resident physicians. IM resident physicians were provided with patient satisfaction education through a conference, real-time individualized patient satisfaction score feedback, monthly recognition, and incentives for high patient-satisfaction scores. Patient satisfaction on physician-related and overall satisfaction questions on the HCAHPS survey. We conducted a difference-in-differences regression analysis comparing IM and non-IM patient responses, adjusting for differences in patient characteristics. In our regression analysis, the percentage of patients who responded positively to all 3 physician-related Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) questions increased by 8.1% in the IM and 1.5% in the control cohorts (absolute difference 6.6%, P = 0.04). The percentage of patients who would definitely recommend this hospital to friends and family increased by 7.1% in the IM and 1.5% in the control cohorts (absolute difference 5.6%, P = 0.02). The national average for the HCAHPS outcomes studied improved by no more than 3.1%. This study was nonrandomized and was conducted at a single site. To our knowledge, this is the first intervention associated with a significant improvement in HCAHPS scores. This may serve as a model to increase patient satisfaction, hospital revenue, and train resident physicians. © 2015 Society of Hospital Medicine.

An efficient parallel simulation of unsteady blood flows in patient-specific pulmonary artery.

Science.gov (United States)

Kong, Fande; Kheyfets, Vitaly; Finol, Ender; Cai, Xiao-Chuan

2018-04-01

Simulation of blood flows in the pulmonary artery provides some insight into certain diseases by examining the relationship between some continuum metrics, eg, the wall shear stress acting on the vascular endothelium, which responds to flow-induced mechanical forces by releasing vasodilators/constrictors. V. Kheyfets, in his previous work, studies numerically a patient-specific pulmonary circulation to show that decreasing wall shear stress is correlated with increasing pulmonary vascular impedance. In this paper, we develop a scalable parallel algorithm based on domain decomposition methods to investigate an unsteady model with patient-specific pulsatile waveforms as the inlet boundary condition. The unsteady model offers tremendously more information about the dynamic behavior of the flow field, but computationally speaking, the simulation is a lot more expensive since a problem which is similar to the steady-state problem has to be solved many times, and therefore, the traditional sequential approach is not suitable anymore. We show computationally that simulations using the proposed parallel approach with up to 10 000 processor cores can be obtained with much reduced compute time. This makes the technology potentially usable for the routine study of the dynamic behavior of blood flows in the pulmonary artery, in particular, the changes of the blood flows and the wall shear stress in the spatial and temporal dimensions. Copyright © 2017 John Wiley & Sons, Ltd.

Evaluation of coronary blood flow reserve by 13N-NH3 positron emission computed tomography (PET) with dipyridamole in the treatment of hypertension with the ACE inhibitor (Cilazapril)

International Nuclear Information System (INIS)

Masuda, Daisuke; Nohara, Ryuji; Tamaki, Nagara

2000-01-01

The purpose of this study was to evaluate the effect of treatment with an angiotensin-converting enzyme (ACE) inhibitor (Cilazapril) for early hypertensive patients in terms of coronary blood flow reserve evaluated by 13 NH 3 -positron emission tomography (PET). Before and after 12 weeks of ACE inhibitor treatment, 13 NH 3 -PET with dipyridamole provocation test was performed, and definite myocardial perfusion and coronary flow reserve (CFR) were calculated. Compared to our normal subjects previously reported (2.61±0.74), average coronary flow reserve was decreased (1.70±0.64 in hypertensive patients), and improved after treatment (1.77±0.52), but not significantly. Of 12 patients, five (42%) showed improved coronary flow reserve from 1.34 to 1.99 without a significant change in the resting flow. Only one patient (8%) showed deterioration after the ACE inhibitor treatment. The coronary vascular resistance (CVR) after ACE inhibitor treatment of the patients with CFR <2.0 decreased significantly compared with those with CFR ≥2.0 (p<0.03). These results indicate that hypertensive patients at the early stage show decreased coronary flow reserve despite having normal resting flow. Treatment with an ACE inhibitor (Cilazapril) for 12 weeks improved coronary flow reserve in 42% of our patients. The CVR of the patients with CFR <2.0 showed improvement compared to those with CFR ≥2.0. This result indicates that an ACE inhibitor (e.g., Cilazapril) should be one of the choices for improving CFR if hypertensive patients in early stage show signs of ischemia or diastolic dysfunction, which may be one of the sequels of reserve restriction. (author)

Patient handover in orthopaedics, improving safety using Information Technology.

Science.gov (United States)

Pearkes, Tim

2015-01-01

Good inpatient handover ensures patient safety and continuity of care. An adjunct to this is the patient list which is routinely managed by junior doctors. These lists are routinely created and managed within Microsoft Excel or Word. Following the merger of two orthopaedic departments into a single service in a new hospital, it was felt that a number of safety issues within the handover process needed to be addressed. This quality improvement project addressed these issues through the creation and implementation of a new patient database which spanned the department, allowing trouble free, safe, and comprehensive handover. Feedback demonstrated an improved user experience, greater reliability, continuity within the lists and a subsequent improvement in patient safety.

Layout and flow of dermatology clinics: principles from operations management.

Science.gov (United States)

Wang, Jordan V

2018-04-15

Dermatology is a medical specialty that experiences high patient demand and long patient wait times. Dermatology clinics should look for ways to improve efficiency through the incorporation of principles from operations management. Addressing the layout and flow of a clinic can lead to operational efficiency. An ideal layout may lead to increased patient volume, satisfaction, and retention.

Leg blood flow is impaired during small muscle mass exercise in patients with COPD

DEFF Research Database (Denmark)

Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

2017-01-01

to both endothelium-independent (SNP) and endothelium-dependent (ACh) stimulation. The results suggests that leg muscle blood flow is impaired during small muscle mass exercise in patients with COPD possibly due to impaired formation of prostacyclin and increased levels of endothelin-1.......Skeletal muscle blood flow is regulated to match the oxygen demand and dysregulation could contribute to exercise intolerance in patients with COPD. We measured leg hemodynamics and metabolites from vasoactive compounds in muscle interstitial fluid and plasma at rest, during one-legged knee...... the formation of interstitial prostacyclin (vasodilator) was only increased in the controls. There was no difference between groups in the nitrite/nitrate levels (vasodilator) in plasma or interstitial fluid during exercise. Moreover, patients and controls showed similar vasodilatory capacity in response...

Improved adaptive genetic algorithm with sparsity constraint applied to thermal neutron CT reconstruction of two-phase flow

Science.gov (United States)

Yan, Mingfei; Hu, Huasi; Otake, Yoshie; Taketani, Atsushi; Wakabayashi, Yasuo; Yanagimachi, Shinzo; Wang, Sheng; Pan, Ziheng; Hu, Guang

2018-05-01

Thermal neutron computer tomography (CT) is a useful tool for visualizing two-phase flow due to its high imaging contrast and strong penetrability of neutrons for tube walls constructed with metallic material. A novel approach for two-phase flow CT reconstruction based on an improved adaptive genetic algorithm with sparsity constraint (IAGA-SC) is proposed in this paper. In the algorithm, the neighborhood mutation operator is used to ensure the continuity of the reconstructed object. The adaptive crossover probability P c and mutation probability P m are improved to help the adaptive genetic algorithm (AGA) achieve the global optimum. The reconstructed results for projection data, obtained from Monte Carlo simulation, indicate that the comprehensive performance of the IAGA-SC algorithm exceeds the adaptive steepest descent-projection onto convex sets (ASD-POCS) algorithm in restoring typical and complex flow regimes. It especially shows great advantages in restoring the simply connected flow regimes and the shape of object. In addition, the CT experiment for two-phase flow phantoms was conducted on the accelerator-driven neutron source to verify the performance of the developed IAGA-SC algorithm.

Effect of additive renin inhibition with aliskiren on renal blood flow in patients with Chronic Heart Failure and Renal Dysfunction (Additive Renin Inhibition with Aliskiren on renal blood flow and Neurohormonal Activation in patients with Chronic Heart Failure and Renal Dysfunction)

NARCIS (Netherlands)

Schroten, Nicolas F.; Damman, Kevin; Hemmelder, Marc H.; Voors, Adriaan A.; Navis, Gerjan; Gaillard, Carlo A. J. M.; van Veldhuisen, Dirk J.; van Gilst, Wiek H.; Hillege, Hans L.

AIMS: We examined the effect of the renin inhibitor, aliskiren, on renal blood flow (RBF) in patients with heart failure with reduced ejection fraction (HFREF) and decreased glomerular filtration rate (GFR). Renal blood flow is the main determinant of GFR in HFREF patients. Both reduced GFR and RBF

Influence of pre-infarction angina, collateral flow, and pre-procedural TIMI flow on myocardial salvage index by cardiac magnetic resonance in patients with ST-segment elevation myocardial infarction.

Science.gov (United States)

Lønborg, Jacob; Kelbæk, Henning; Vejlstrup, Niels; Bøtker, Hans Erik; Kim, Won Yong; Holmvang, Lene; Jørgensen, Erik; Helqvist, Steffen; Saunamäki, Kari; Thuesen, Leif; Krusell, Lars Romer; Clemmensen, Peter; Engstrøm, Thomas

2012-05-01

In patients with ST-segment elevation myocardial infarction (STEMI) pre-infarction angina, pre-procedural TIMI flow and collateral flow to the myocardium supplied by the infarct related artery are suggested to be cardioprotective. We evaluated the effect of these factors on myocardial salvage index (MSI) and infarct size adjusting for area at risk in patients with STEMI treated with primary percutaneous coronary intervention. Cardiac magnetic resonance (CMR) was used to measure myocardial area at risk within 1-7 days and final infarct size 90 ± 21 days after the STEMI in 200 patients. MSI was calculated as (area-at-risk infarct size) / area-at-risk. Patients with pre-infarction angina had a median MSI of 0.80 (IQR 0.67 to 0.86) versus 0.72 (0.61 to 0.80) in those without pre-infarction angina, P = 0.004). In a regression analysis of the infarct size plotted against the area-at-risk there was a strong trend that the line for the pre-infarction angina group was below the one for the non-angina group (P = 0.05). Patients with pre-procedural TIMI flow 0/1, 2 and 3 had a median MSI of (0.69 (IQR 0.59 to 0.76), 0.78 (0.68 to 0.86) and 0.85 (0.77 to 0.91), respectively (PCollateral flow did not change MSI (P = 0.45) nor area-at-risk (P = 0.40) and no significant difference in infarct size adjusted for area at risk (P = 0.25) was observed. Pre-infarction angina increases MSI in patients with STEMI supporting the theory that pre-infarction angina leads to ischemic preconditioning. As opposed to the presence of angiographically visible collateral flow to the infarct area pre-procedural TIMI flow is strongly associated with MSI.

Leveraging information technology to drive improvement in patient satisfaction.

Science.gov (United States)

Nash, Mary; Pestrue, Justin; Geier, Peter; Sharp, Karen; Helder, Amy; McAlearney, Ann Scheck

2010-01-01

A healthcare organization's commitment to quality and the patient experience requires senior leader involvement in improvement strategies, and accountability for goals. Further, improvement strategies are most effective when driven by data, and in the world of patient satisfaction, evidence is growing that nurse leader rounding and discharge calls are strategic tactics that can improve patient satisfaction. This article describes how The Ohio State University Medical Center (OSUMC) leveraged health information technology (IT) to apply a data-driven strategy execution to improve the patient experience. Specifically, two IT-driven approaches were used: (1) business intelligence reporting tools were used to create a meaningful reporting system including dashboards, scorecards, and tracking reports and (2) an improvement plan was implemented that focused on two high-impact tactics and data to hardwire accountability. Targeted information from the IT systems enabled clinicians and administrators to execute these strategic tactics, and senior leaders to monitor achievement of strategic goals. As a result, OSUMC's inpatient satisfaction scores on the Hospital Consumer Assessment of Healthcare Providers and Systems survey improved from 56% nines and tens in 2006 to 71% in 2009. © 2010 National Association for Healthcare Quality.

Effective management of patients with acute ischemic stroke based on lean production on thrombolytic flow optimization.

Science.gov (United States)

Liang, Zhuoyuan; Ren, Lijie; Wang, Ting; Hu, Huoyou; Li, Weiping; Wang, Yaping; Liu, Dehong; Lie, Yi

2016-12-01

The efficacy of thrombolytic therapy for acute ischemic stroke (AIS) decreases when the administration of tissue plasminogen activator (tPA) is delayed. Derived from Toyota Production System, lean production aims to create top-quality products with high-efficiency procedures, a concept that easily applies to emergency medicine. In this study, we aimed to determine whether applying lean principles to flow optimization could hasten the initiation of thrombolysis. A multidisciplinary team (Stroke Team) was organized to implement an ongoing, continuous loop of lean production that contained the following steps: decomposition, recognition, intervention, reengineering and assessment. The door-to-needle time (DNT) and the percentage of patients with DNT ≤ 60 min before and after the adoption of lean principles were used to evaluate the efficiency of our flow optimization. Thirteen patients with AIS in the pre-lean period and 43 patients with AIS in the lean period (23 in lean period I and 20 patients in lean period II) were consecutively enrolled in our study. After flow optimization, we reduced DNT from 90 to 47 min (p < 0.001 ¤ ). In addition, the percentage of patients treated ≤60 min after hospital arrival increased from 38.46 to 75.0 % (p = 0.015 ¤ ). Adjusted analysis of covariance confirmed a significant influence of optimization on delay of tPA administration (p < 0.001). The patients were more likely to have a good prognosis (mRS ≤ 2 at 90 days) after the flow optimization (30.77-75.00 %, p = 0.012 ¤ ). Our study may offer an effective approach for optimizing the thrombolytic flow in the management of AIS.

Analysis of placenta vascularization in patients with uterine altered artery Doppler flow velocity exams.

Science.gov (United States)

Gilio, Daniel Bruno; Miranda Corrêa, Rosana Rosa; Souza de Oliveira Guimarães, Camila; Peres, Luiz Cesar; Marques Salge, Ana Karina; Cavellani, Camila Lourencini; de Paula Antunes Teixeira, Vicente; Costa da Cunha Castro, Eumenia

2009-08-01

One of the frequent questions in obstetric practice is to determine placental vascular changes that may account for abnormal Doppler flow velocity alterations in maternal uterine vessels from women and fetuses without pregnancy pathology. A retrospective morphometric study was realized using 27 placentas from patients submitted for Doppler flow velocity exam during pregnancy. The placentas were morphologically examined using hematoxylin-eosin staining. Measurements of villi were made with the use of a video camera coupled to a common light microscope and a computer with automatic image analyzing software. Of the 27 placentas, 13 (48%) were of patients showing unaltered Doppler and 14 (52%) showing altered Doppler. The number of stem villi vessels was significantly larger in the placentas of patients with Doppler exam alterations (P = 0.003). This group also presented greater stem villi vessel thickness, although without significant difference. The number of intermediary and terminal villi vessels was greater in the placentas of patients with altered Doppler exams (P < 0.001), and a greater terminal villi area was observed in these cases (P < 0.001). The morphological proof that uterine artery Doppler flow velocity exam alterations are associated with placental vascular alterations demonstrates the importance of this exam during prenatal care, even in the absence of maternal-fetal alterations.

Topical nasal steroid treatment does not improve CPAP compliance in unselected patients with OSAS.

Science.gov (United States)

Strobel, Werner; Schlageter, Manuel; Andersson, Morgan; Miedinger, David; Chhajed, Prashant N; Tamm, Michael; Leuppi, Jörg D

2011-02-01

Continuous positive airways pressure (CPAP) for treatment of obstructive sleep apnea (OSA) can produce troublesome nasal symptoms (i.e. congestion, rhinorrhea) that may reduce the compliance of CPAP. Topical nasal steroids are often prescribed to reduce these side effects, although scientific data are scarce supporting any benefits of this treatment for CPAP-induced nasal side effects. To study whether a topical nasal steroid can reduce CPAP-induced nasal symptoms and improve CPAP adherence during the initial phase of OSA treatment. A randomized, double-blinded, placebo-controlled study with fluticasone propionate 100 μg/nasal cavity twice daily Treatment was started 10 days prior to and continued throughout the first 4 weeks of CPAP. 63 patients who were selected for CPAP treatment participated. Nasal symptoms were recorded, nasal patency was assessed and lung function was measured with a peak flow meter. The patients' adherence to CPAP was recorded by the CPAP device. Total nasal symptoms increased from baseline to 4 wks after CPAP use for both nasal treatments (p < 0.05). No differences in total nasal symptoms between treatments were seen (p = 1), and no differences in nasal peak flow values after treatment were seen (p = 0.11). Moreover, there were no differences in CPAP use between the treatments. Fluticasone propionate as a nasal topical steroid does not reduce CPAP-induced unwanted nasal side effects, and has no beneficial effect on CPAP compliance during the first four weeks of treatment in unselected patients with OSAS. Copyright © 2010 Elsevier Ltd. All rights reserved.

Salivary flow and xerostomia in patients with type 2 diabetes.

Science.gov (United States)

Carramolino-Cuéllar, Esther; Lauritano, Dorina; Silvestre, Francisco-Javier; Carinci, Francesco; Lucchese, Alberta; Silvestre-Rangil, Javier

2018-05-01

Saliva is secreted by the major and minor salivary glands. There are a number of physiological factors that can reduce this secretion such as age, sex, body weight, number of teeth present in the mouth or time of day. This decrease may also be caused by the use of certain drugs, radiotherapy for head and neck cancer, chronic rheumatic diseases such as Sjögren's syndrome and other systemic disorders such as diabetes mellitus (DM). Objective of this study was to investigate the effect of type 2 DM on salivary secretion and its relation to the sensation of xerostomia. Forty-seven patients with type 2 DM and 46 healthy individuals, aged 40-80, participated in the study. Samples of saliva were collected, at rest and after stimulation, at baseline and after the administration of a meal. A questionnaire of 10 items was used to define the patients' sensations of xerostomia. For statistical analysis, the Mann-Whitney test was used to assess the difference in salivary flow between the two groups and the relationship between the response to each of the questions and salivary flow levels. The degree of the patients' sensation of xerostomia was analysed by the Fisher test. There was a significant decrease in total saliva levels at rest in patients with type 2 DM compared to the control group. The study group also experienced higher levels of dryness at night and on waking as well as a greater sensation of lingual burning compared to the control group. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

High-Flow Nasal Oxygen in Patient With Obstructive Sleep Apnea Undergoing Awake Craniotomy: A Case Report.

Science.gov (United States)

Wong, Jaclyn W M; Kong, Amy H S; Lam, Sau Yee; Woo, Peter Y M

2017-12-15

Patients with obstructive sleep apnea are frequently considered unsuitable candidates for awake craniotomy due to anticipated problems with oxygenation, ventilation, and a potentially difficult airway. At present, only a handful of such accounts exist in the literature. Our report describes the novel use of high-flow nasal oxygen therapy for a patient with moderate obstructive sleep apnea who underwent an awake craniotomy under deep sedation. The intraoperative application of high-flow nasal oxygen therapy achieved satisfactory oxygenation, maintained the partial carbon dioxide pressure within a reasonable range even during periods of deep sedation, permitted responsive patient monitoring during mapping, and provided excellent patient and surgeon satisfaction.

Performance improvement of a PEMFC system controlling the cathode outlet air flow

Energy Technology Data Exchange (ETDEWEB)

Feroldi, Diego; Serra, Maria; Riera, Jordi [Institut de Robotica i Informatica Industrial, Universitat Politecnica de Catalunya-Consejo Superior de Investigaciones Cientificas, C. Llorens i Artigas 4, 08028 Barcelona (Spain)

2007-06-10

This paper presents a stationary and dynamic study of the advantages of using a regulating valve for the cathode outlet flow in combination with the compressor motor voltage as manipulated variables in a fuel cell system. At a given load current, the cathode input and output flow rate determine the cathode pressure and stoichiometry, and consequently determine the oxygen partial pressure, the generated voltage and the compressor power consumption. In order to maintain a high efficiency during operation, the cathode output regulating valve has to be adjusted to the operating conditions, specially marked by the current drawn from the stack. Besides, the appropriate valve manipulation produces an improvement in the transient response of the system. The influence of this input variable is exploited by implementing a predictive control strategy based on dynamic matrix control (DMC), using the compressor voltage and the cathode output regulating valve as manipulated variables. The objectives of this control strategy are to regulate both the fuel cell voltage and oxygen excess ratio in the cathode, and thus, to improve the system performance. All the simulation results have been obtained using the MATLAB-Simulink environment. (author)

Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

Directory of Open Access Journals (Sweden)

Serkan Yazıcı

2015-01-01

Full Text Available We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF. 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+, B cells (HLA-DR+, CD19+, and HLA-DR+CD19+, NKT cells (CD3+CD16+CD56+, and NK cells (CD3−CD16+CD56+. The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression.

PROGRESSIVE MUSCLE RELAXATION INCREASE PEAK EXPIRATORY FLOW RATE ON CHRONIC OBSTRUCTIVE PULMONARY DISEASE PATIENTS

Directory of Open Access Journals (Sweden)

Tintin Sukartini

2017-07-01

Full Text Available Introduction: Limited progressive air flow in Chronic Obstructive Pulmonary Disease (COPD can caused by small airway disease (bronchiolitis obstructive and loss of elasticity of the lung (emphysema. Further it can be decreasing the quality of life in COPD patients because dyspnea and uncomfortable in activity. Progressive muscle relaxation (PMR is one of the relaxation technique that can repair pulmonary ventilation by decreasing chronic constriction of the respiratory muscles. The objective of this study was to analyze the effect of progressive muscle relaxation on raised peak expiratory flow rate (PEFR. Method: A pre-experimental one group pre-post test design was used in this study. Population was all of the COPD patients at Pulmonary Specialist Polyclinic Dr Mohamad Soewandhie Surabaya. There were 8 respondents taken by using purposive sampling. PEFR was counted by using peak flow meter every six day. Data were analyzed by using Paired t-Test with significance level  p≤0.05. Result: The result showed that PMR had significance level on increasing of PEFR (p=0.012. Discussion: It can be concluded that PMR has an effect on raise PEFR. Further studies are recommended to measure the effect of PMR on respiratory rate (RR, heart rate (HR subjective dyspnoe symptoms, forced expiration volume on the first minute (FEV1 and mid maximum flow rate (MMFR in COPD patients.

Improving Long-term Post-wildfire hydrologic simulations using ParFlow

Science.gov (United States)

Lopez, S. R.; Kinoshita, A. M.

2015-12-01

Wildfires alter the natural hydrologic processes within a watershed. After vegetation is burned, the combustion of organic material and debris settles into the soil creating a hydrophobic layer beneath the soil surface with varying degree of thickness and depth. Vegetation regrowth rates vary as a function of radiative exposure, burn severity, and precipitation patterns. Hydrologic models used by the Burned Area Emergency Response (BAER) teams use input data and model calibration constraints that are generally either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models estimate runoff measurements at the watershed outlet; however, do not provide a distributed hydrologic simulation at each point within the watershed. This work uses ParFlow, a three-dimensional, distributed hydrologic model to (1) correlate burn severity with hydrophobicity, (2) evaluate vegetation recovery rate on water components, and (3) improve flood prediction for managers to help with resource allocation and management operations in burned watersheds. ParFlow is applied to Devil Canyon (43 km2) in San Bernardino, California, which was 97% burned in the 2003 Old Fire. The model set-up uses a 30m-cell size resolution over a 6.7 km by 6.4 km lateral extent. The subsurface reaches 30 m and is assigned a variable cell thickness. Variable subsurface thickness allows users to explicitly consider the degree of recovery throughout the stages of regrowth. Burn severity maps from remotely sensed imagery are used to assign initial hydrophobic layer parameters and thickness. Vegetation regrowth is represented with satellite an Enhanced Vegetation Index. Pre and post-fire hydrologic response is evaluated using runoff measurements at the watershed outlet, and using water component (overland flow, lateral flow, baseflow) measurements.

Cerebral blood flow and metabolism in patients with aphasia due to basal ganglionic lesion

International Nuclear Information System (INIS)

Kitamura, Shin; Kato, Toshiaki; Ujike, Takashi; Kuroki, Soemu; Terashi, Akiro

1987-01-01

Cerebral blood flow and metabolism in right handed eight patients with subcortical lesion and aphasia were measured to investigate the correlation between aphasia and functional changes in cerebral blood flow (CBF) and cerebral oxygen consumption (CMRO 2 ) in the cortex and the basal ganglionic region. All patients had no lesion in the cortex, but in the basal ganglionic region (putamen, caudate nucleus, internal capsule, and periventricular white matter) on CT images. Patients with bilateral lesion were excluded in this study. Six patients with cerebral infarction in the left basal ganglionic region and two patients with the left putammal hemorrhage were examined. Five patients had non fluent Broca's type speech, two patients had poor comprehension, fluent Wernicke-type speech and one patient was globally aphasic. CBF, CMRO 2 , and oxygen extraction fraction were measured by the positron emission tomography using 15 O 2 , C 15 O 2 inhalation technique. In addition to reduction of CBF and CMRO 2 in the basal ganglionic region, CBF and CMRO 2 decreased in the left frontal cortex especially posterior part in four patients with Broca's aphasia. In two patients with Wernicke type aphasia, CBF and CMRO 2 decreased in the basal ganglionic region and the left temporal cortex. In a globally aphasic patient, marked reduction of CBF and CMRO 2 was observed in the left frontal and temporal cortex, in addition to the basal ganglionic region. These results suggest that dysfunction of cortex as well as that of basal ganglionic region might be related to the occurence of aphasia. However, in one patient with Broca's ahasia, CBF and CMRO 2 were preserved in the cortex and metabolic reduction was observed in only basal ganglia. This case indicates the relation between basal ganglionic lesion and the occurrence of aphasia. These results suggest that measurements of cerebral blood flow and metabolism were necessary to study the responsible lesion for aphasia. (author)

Improved evaluation of the coronary collateral circulation measuring the regional blood flow with 133Xe

International Nuclear Information System (INIS)

Franz, N.; Strangfeld, D.; Romaniuk, P.; Heublein, B.

1988-01-01

In 40 patients with angina pectoris catheter diagnostic measurements of the myocardial flow were carried out after intracoronary application of 133 Xe at rest and after oral application of Curantyl in order to obtain a better evaluation of coronary collaterals. The results show relations between angiographically detected coronary collaterals and the reduced coronary reserve. A quantitative measurement of collaterals from the angiogram facilitates a more precise evaluation of the relation between coronary sclerosis and myocardial flow. (author)

Utilizing a disease management approach to improve ESRD patient outcomes.

Science.gov (United States)

Anand, Shaan; Nissenson, Allen R

2002-01-01

In this era of processes and systems to improve quality, disease management is one methodology to improve care delivery and outcomes for patients with chronic kidney disease (CKD). In most disease management systems a senior renal nurse coordinates all aspects of the patient's care and ensures that the prescribed and necessary care is delivered for both CKD-related and comorbid conditions. The nurse also continually monitors outcomes on quality indicators and key performance measures. These outcome data are then aggregated and analyzed, are compared with local and national benchmarks, and drive the continuous quality improvement (CQI) process. Such a system attempts to centralize the currently fragmented care delivery system, continually improve patient outcomes, and conserve scarce economic resources. Early data suggest a disease management approach may improve both the morbidity and mortality of CKD patients.

Improving treatment in Hispanic/Latino patients.

Science.gov (United States)

Cersosimo, Eugenio; Musi, Nicolas

2011-10-01

The prevalence of type 2 diabetes mellitus is higher in Hispanic/Latino individuals living in the United States compared with their non-Hispanic white counterparts. Many factors contribute to the increased prevalence of type 2 diabetes, including biological characteristics, socioeconomic conditions, and cultural aspects. The contribution of genetics to the risk of type 2 diabetes in Hispanic/Latino patients is becoming increasingly clear, but this inherent risk factor cannot be modified. However, certain socioeconomic and cultural factors, such as reduced access to healthcare, language barriers, cultural beliefs, and lack of cultural competence by the healthcare provider, are modifiable and should be overcome in order to improve the management of type 2 diabetes in Hispanic/Latino patients. At the healthcare system level, policies should be put into place to reduce disparities between Hispanics/Latinos and non-Hispanic whites regarding health insurance coverage and access to healthcare. At the healthcare provider and patient level, cultural beliefs should be taken into consideration when selecting adequate treatment. Overall, type 2 diabetes management should be individualized by identifying the preferred language and level of acculturation for each patient. These considerations are necessary to further improve communication through culturally appropriate educational materials and programs. These strategies may help to overcome the barriers in the treatment of type 2 diabetes in Hispanic/Latino patients. Copyright © 2011 Elsevier Inc. All rights reserved.

Progenitor Hematopoietic Cells Implantation Improves Functional Capacity of End Stage Coronary Artery Disease Patients with Advanced Heart Failure

Directory of Open Access Journals (Sweden)

Yoga Yuniadi

2016-01-01

Full Text Available Background. Proangiogenic Hematopoietic Cells (PHC which comprise diverse mixture of cell types are able to secrete proangiogenic factors and interesting candidate for cell therapy. The aim of this study was to seek for benefit in implantation of PHC on functional improvement in end stage coronary artery disease patients with advanced heart failure. Methods. Patients with symptomatic heart failure despite guideline directed medical therapy and LVEF less than 35% were included. Peripheral blood mononuclear cells were isolated, cultivated for 5 days, and then harvested. Flow cytometry and cell surface markers were used to characterize PHC. The PHC were delivered retrogradely via sinus coronarius. Echocardiography, myocardial perfusion, and clinical and functional data were analyzed up to 1-year observation. Results. Of 30 patients (56.4±7.40 yo preimplant NT proBNP level is 5124.5±4682.50 pmol/L. Harvested cells characterized with CD133, CD34, CD45, and KDR showed 0.87±0.41, 0.63±0.66, 99.00±2.60, and 3.22±3.79%, respectively. LVEF was improved (22±5.68 versus 26.8±7.93, p<0.001 during short and long term observation. Myocardial perfusion significantly improved 6 months after treatment. NYHA Class and six-minute walk test are improved during short term and long term follow-up. Conclusion. Expanded peripheral blood PHC implantation using retrograde delivery approach improved LV systolic function, myocardial perfusion, and functional capacity.

Improving patient care through student leadership in team quality improvement projects.

Science.gov (United States)

Tschannen, Dana; Aebersold, Michelle; Kocan, Mary Jo; Lundy, Francene; Potempa, Kathleen

2015-01-01

In partnership with a major medical center, senior-level nursing students completed a root cause analysis and implementation plan to address a unit-specific quality issue. To evaluate the project, unit leaders were asked their perceptions of the value of the projects and impact on patient care, as well as to provide exemplars depicting how the student root cause analysis work resulted in improved patient outcome and/or unit processes. Liaisons noted benefits of having an RCA team, with positive impact on patient outcomes and care processes.

Effect of additive renin inhibition with aliskiren on renal blood flow in patients with Chronic Heart Failure and Renal Dysfunction (Additive Renin Inhibition with Aliskiren on renal blood flow and Neurohormonal Activation in patients with Chronic Heart Failure and Renal Dysfunction).

Science.gov (United States)

Schroten, Nicolas F; Damman, Kevin; Hemmelder, Marc H; Voors, Adriaan A; Navis, Gerjan; Gaillard, Carlo A J M; van Veldhuisen, Dirk J; Van Gilst, Wiek H; Hillege, Hans L

2015-05-01

We examined the effect of the renin inhibitor, aliskiren, on renal blood flow (RBF) in patients with heart failure with reduced ejection fraction (HFREF) and decreased glomerular filtration rate (GFR). Renal blood flow is the main determinant of GFR in HFREF patients. Both reduced GFR and RBF are associated with increased mortality. Aliskiren can provide additional renin-angiotensin-aldosterone system inhibition and increases RBF in healthy individuals. Patients with left ventricular ejection fraction ≤45% and estimated GFR 30 to 75 mL/min per 1.73 m(2) on optimal medical therapy were randomized 2:1 to receive aliskiren 300 mg once daily or placebo. Renal blood flow and GFR were measured using radioactive-labeled (125)I-iothalamate and (131)I-hippuran at baseline and 26 weeks. After 41 patients were included, the trial was halted based on an interim safety analysis showing futility. Mean age was 68 ± 9 years, 82% male, GFR (49 ± 16 mL/min per 1.73 m(2)), RBF (294 ± 77 mL/min per 1.73 m(2)), and NT-proBNP 999 (435-2040) pg/mL. There was a nonsignificant change in RBF after 26 weeks in the aliskiren group compared with placebo (-7.1 ± 30 vs +14 ± 54 mL/min per 1.73 m(2); P = .16). However, GFR decreased significantly in the aliskiren group compared with placebo (-2.8 ± 6.0 vs +4.4 ± 9.6 mL/min per 1.73 m(2); P = .01) as did filtration fraction (-2.2 ± 3.3 vs +1.1 ± 3.1%; P = .01). There were no significant differences in plasma aldosterone, NT-proBNP, urinary tubular markers, or adverse events. Plasma renin activity was markedly reduced in the aliskiren group versus placebo throughout the treatment phase (P = .007). Adding aliskiren on top of optimal HFREF medical therapy did not improve RBF and was associated with a reduction of GFR and filtration fraction. Copyright © 2015 Mosby, Inc. All rights reserved.

Preliminary studies of regional cerebral blood flow changes in patients with leukoaraiosis

International Nuclear Information System (INIS)

Li Yaming; Ren Yan; He Qiu

1997-01-01

PURPOSE: To investigate changes of regional cerebral blood flow (rCBF) in leukoaraiosis (LA) lesion and cortical regions and analyse the relation between rCBF changes and dementia. METHODS: Regional cerebral blood flow perfusion imaging with SPECT was performed in 49 patients with subcortical multiple cerebral infarction, including 24 cases company LA [LA(+)], 25 cases not company LA[LA(-)] and 10 normal subjects. The relative analysis was made between rCBF changes and cognitive scores. RESULTS: Compared the LA(+) with control, the rCBFs in frontal, parietal, temporal cortexes and LA lesion significantly decreased (P<0.05). The rCBF of frontal, parietal cortexes and LA lesions was also significantly decreased (P<0.05) compared with LA(-) groups. The cognitive scores were significantly related with rCBF changes in frontal cortex and LA lesion (r = 0.765, P<0.01 and r = 0.439, P<0.05). CONCLUSION: In patients with subcortical multiple cerebral infarction company LA lesion, there were extensive ischemic hypoperfusion changes in the cortical regions and LA lesion, which may response to decreased cerebral function and had certain relationship with dementia. The examination with SPECT cerebral blood flow perfusion imaging had unique advantage and value

Improving patient safety: lessons from rock climbing.

Science.gov (United States)

Robertson, Nic

2012-02-01

How to improve patient safety remains an intractable problem, despite large investment and some successes. Academics have argued that the root of the problem is a lack of a comprehensive 'safety culture' in hospitals. Other safety-critical industries such as commercial aviation invest heavily in staff training to develop such a culture, but comparable programmes are almost entirely absent from the health care sector. In rock climbing and many other dangerous activities, the 'buddy system' is used to ensure that safety systems are adhered to despite adverse circumstances. This system involves two or more people using simple checks and clear communication to prevent problems causing harm. Using this system as an example could provide a simple, original and entertaining way of introducing medical students to the idea that human factors are central to ensuring patient safety. Teaching the buddy system may improve understanding and acceptance of other patient safety initiatives, and could also be used by junior doctors as a tool to improve the safety of their practice. © Blackwell Publishing Ltd 2012.

Stability Improvement of High-Pressure-Ratio Turbocharger Centrifugal Compressor by Asymmetric Flow Control-Part I: Non-Axisymmetrical Flow in Centrifugal Compressor.

Science.gov (United States)

Yang, Mingyang; Zheng, Xinqian; Zhang, Yangjun; Bamba, Takahiro; Tamaki, Hideaki; Huenteler, Joern; Li, Zhigang

2013-03-01

This is Part I of a two-part paper documenting the development of a novel asymmetric flow control method to improve the stability of a high-pressure-ratio turbocharger centrifugal compressor. Part I focuses on the nonaxisymmetrical flow in a centrifugal compressor induced by the nonaxisymmetrical geometry of the volute while Part II describes the development of an asymmetric flow control method to avoid the stall on the basis of the characteristic of nonaxisymmetrical flow. To understand the asymmetries, experimental measurements and corresponding numerical simulation were carried out. The static pressure was measured by probes at different circumferential and stream-wise positions to gain insights about the asymmetries. The experimental results show that there is an evident nonaxisymmetrical flow pattern throughout the compressor due to the asymmetric geometry of the overhung volute. The static pressure field in the diffuser is distorted at approximately 90 deg in the rotational direction of the volute tongue throughout the diffuser. The magnitude of this distortion slightly varies with the rotational speed. The magnitude of the static pressure distortion in the impeller is a function of the rotational speed. There is a significant phase shift between the static pressure distributions at the leading edge of the splitter blades and the impeller outlet. The numerical steady state simulation neglects the aforementioned unsteady effects found in the experiments and cannot predict the phase shift, however, a detailed asymmetric flow field structure is obviously obtained.

Improving patient satisfaction with pain management using Six Sigma tools.

Science.gov (United States)

DuPree, Erin; Martin, Lisa; Anderson, Rebecca; Kathuria, Navneet; Reich, David; Porter, Carol; Chassin, Mark R

2009-07-01

Patient satisfaction as a direct and public measure of quality of care is changing the way hospitals address quality improvement. The feasibility of using the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) methodology to improve patient satisfaction as it relates to pain management was evaluated. This project used the DMAIC methodology to improve patients' overall satisfaction with pain management on two inpatient units in an urban academic medical center. Pre- and postintervention patient surveys were conducted. The DMAIC methodology provided a data-driven structure to determine the optimal improvement strategies, as well as a long-term plan for maintaining any improvements. In addition, the Change Acceleration Process (CAP) was used throughout the project's various DMAIC stages to further the work of the team by creating a shared need to meet the objectives of the project. Overall satisfaction with pain management "excellent" ratings increased from 37% to 54%. Both units surpassed the goal of at least 50% of responses in the "excellent" category. Several key drivers of satisfaction with pain management were uncovered in the Analyze phase of the project, and each saw rating increases from the pre-intervention to postintervention surveys. Ongoing monitoring by the hospital inpatient satisfaction survey showed that the pain satisfaction score improved in subsequent quarters as compared with the pre-intervention period. The Six Sigma DMAIC methodology can be used successfully to improve patient satisfaction. The project led to measurable improvements in patient satisfaction with pain management, which have endured past the duration of the Six Sigma project. The Control phase of DMAIC allows the improvements to be incorporated into daily operations.