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Sample records for temporal bone pneumatization

  1. Statistical model estimating the occurrence of otitis media from temporal bone pneumatization

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Rasmussen, N

    1994-01-01

    In order to investigate the relationship between the pneumatization of temporal bones and the occurrence of otitis media in Greenlandic Inuit, 36 Greenlandic Inuit were examined by radiography of the temporal bones. The pneumatized cell area was measured planimetrically. All subjects answered...

  2. Cranial base morphology and temporal bone pneumatization in Asian Homo erectus.

    Science.gov (United States)

    Balzeau, Antoine; Grimaud-Hervé, Dominique

    2006-10-01

    The external morphological features of the temporal bone are used frequently to determine taxonomic affinities of fossils of the genus Homo. Temporal bone pneumatization has been widely studied in great apes and in early hominids. However, this feature is rarely examined in the later hominids, particularly in Asian Homo erectus. We provide a comparative morphological and quantitative analysis of Asian Homo erectus from the sites of Ngandong, Sambungmacan, and Zhoukoudian, and of Neandertals and anatomically modern Homo sapiens in order to discuss causes and modalities of temporal bone pneumatization during hominid evolution. The evolution of temporal bone pneumatization in the genus Homo is more complex than previously described. Indeed, the Zhoukoudian fossils have a unique pattern of temporal bone pneumatization, whereas Ngandong and Sambungmacan fossils, as well as the Neandertals, more closely resemble the modern human pattern. Moreover, these Chinese fossils are characterized by a wide midvault and a relatively narrow occipital bone. Our results support the point of view that cell development does not play an active role in determining cranial base morphology. Instead, pneumatization is related to available space and to temporal bone morphology, and its development is related to correlated morphology and the relative disposition of the bones and cerebral lobes. Because variation in pneumatization is extensive within the same species, the phyletic implications of pneumatization are limited in the taxa considered here.

  3. Pneumatization of the Temporal Bones in a Greenlandic Inuit Anthropological Material

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N

    1991-01-01

    The degree of pneumatization of the temporal bones correlates with exposure during childhood and adolescence to infectious middle ear diseases (IMED), both acute and chronic. The pneumatized area as seen on cranial X-rays can be measured. This was applied to an anthropological material in order...

  4. Classification of temporal bone pneumatization based on sigmoid sinus using computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Han, S.-J. [Department of Otorhinolaryngology, National Health Insurance Corporation Ilsan Hospital, Seoul (Korea, Republic of); Song, M.H. [Department of Otorhinolaryngology, Yonsei University College of Medicine, Kang-nam Gu, Do-gok Dong, 146-92, Seoul, Republic of Korea 135-720 (Korea, Republic of); Kim, J. [Department of Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, W.-S. [Department of Otorhinolaryngology, Yonsei University College of Medicine, Kang-nam Gu, Do-gok Dong, 146-92, Seoul, Republic of Korea 135-720 (Korea, Republic of); Lee, H.-K. [Department of Otorhinolaryngology, Yonsei University College of Medicine, Kang-nam Gu, Do-gok Dong, 146-92, Seoul, Republic of Korea 135-720 (Korea, Republic of)], E-mail: hoki@yuhs.ac

    2007-11-15

    Aim: To analyse several reference structures using axial computed tomography (CT) imaging of the temporal bone, which may reflect pneumatization of the entire temporal bone by statistical correlation to the actual volume of the temporal bone measured using three-dimensional reconstruction. Materials and methods: One hundred and sixteen temporal bones were studied, comprising 48 with normal findings and 68 sides showing chronic otitis media or temporal bone fracture. After measuring the volume of temporal bone air cells by the volume rendering technique using three-dimensional reconstruction images, classification of temporal bone pneumatization was performed using various reference structures on axial images to determine whether significant differences in the volume of temporal bone air cells could be found between the groups. Results: When the sigmoid sinus at the level of the malleoincudal complex was used in the classification, there were statistically significant differences between the groups that correlated with the entire volume of the temporal bone. Grouping based on the labyrinth and the ascending carotid artery showed insignificant differences in volume. Furthermore, there was no significant correlation between the cross-sectional area of the antrum and the entire volume of the temporal bone. Conclusion: The degree of pneumatization of temporal bone can be estimated easily by the evaluation of the air cells around the sigmoid sinus on axial CT images.

  5. Pneumatization of the zygomatic process of temporal bone on computed tomograms

    Directory of Open Access Journals (Sweden)

    Friedrich, Reinhard E.

    2016-06-01

    Full Text Available Purpose: Zygomatic air cells (ZAC are a variant of temporal bone pneumatization that needs no treatment. However, ZAC can have an impact on surgical procedures in the temporo-mandibular joint region. Recent reports suggest that computed tomography will disclose more ZAC than can be diagnosed on panoramic radiography. The aim of this study was to analyze ZAC prevalence on CT in a population that was not pre-selected by admission to a dental clinic. Furthermore, an extensive literature review was performed to assess the prevalence of ZAC and to address the impact of imaging technique on the definition of the item.Material and methods: Digitalized cranial CTs of 2007 patients were retrospectively analyzed. The Frankfort horizontal was used to define a ZAC on sagittal CTs. Results: In this study group, 806 were female (40.16% and 1,201 were male (59.84%. Mean age was 49.96 years in the whole group (female: 55.83 years, male: 46.01 years. A ZAC was diagnosed in 152 patients (female: 66, male: 86. Unilateral ZAC surpasses bilateral findings (115 vs. 37 patients. ZAC were diagnosed in children 5 years of age and older. Sectional imaging techniques show a better visualization of the region of interest. However, presently an increase of ZAC prevalence attributable to imaging technique cannot conclusively be derived from the current literature. The normal finding of a ZAC on radiograms is a sharply defined homogenous transparent lesion restricted to the zygomatic process of the temporal bone that has no volume effect on the shape of the process.Conclusion: ZAC is an anatomical variant of the temporal bone that has come into focus of maxillofacial radiology due to its noticeable aspect on panoramic radiograms. The harmless variant can be expected in about one in thirteen individuals undergoing facial radiology. Panoramic radiograms appear to be sufficient to present ZAC of relevant size. However, in preparation for surgical procedures affecting the

  6. Complications of occipital bone pneumatization

    International Nuclear Information System (INIS)

    Moss, Mary; Roche, Jim; Biggs, Michael; Forer, Martin; Fagan, Paul; Davis, Martin

    2004-01-01

    Four cases of occipital bone pneumatization and subsequent complications are described, which include a pathological fracture of C 1 and the occipital bone, spontaneous subcutaneous emphysema and pneumatocele formation. Reviews of the published literature and possible aetiological factors have been discussed Copyright (2004) Blackwell Publishing Asia Pty Ltd

  7. Evaluation of temporal bone pneumatization on high resolution CT (HRCT) measurements of the temporal bone in normal and otitis media group and their correlation to measurements of internal auditory meatus, vestibular or cochlear aqueduct

    International Nuclear Information System (INIS)

    Nakamura, Miyako

    1988-01-01

    High resolution CT axial scans were made at the three levels of the temoral bone 91 cases. These cases consisted of 109 sides of normal pneumatization (NR group) and 73 of poor pneumatization resulted by chronic otitis (OM group). NR group included sensorineural hearing loss cases and/or sudden deafness on the side. Three levels of continuous slicing were chosen at the internal auditory meatus, the vestibular and the cochlear aqueduct, respectively. In each slice two sagittal and two horizontal measurements were done on the outer contour of the temporal bone. At the proper level, diameter as well as length of the internal acoustic meatus, the vestibular or the cochlear aqueduct were measured. Measurements of the temporal bone showed statistically significant difference between NR and OM groups. Correlation of both diameter and length of the internal auditory meatus to the temporal bone measurements were statistically significant. Neither of measurements on the vestibular or the cochlear aqueduct showed any significant correlation to that of the temporal bone. (author)

  8. Otosclerosis: Temporal Bone Pathology.

    Science.gov (United States)

    Quesnel, Alicia M; Ishai, Reuven; McKenna, Michael J

    2018-04-01

    Otosclerosis is pathologically characterized by abnormal bony remodeling, which includes bone resorption, new bone deposition, and vascular proliferation in the temporal bone. Sensorineural hearing loss in otosclerosis is associated with extension of otosclerosis to the cochlear endosteum and deposition of collagen throughout the spiral ligament. Persistent or recurrent conductive hearing loss after stapedectomy has been associated with incomplete footplate fenestration, poor incus-prosthesis connection, and incus resorption in temporal bone specimens. Human temporal bone pathology has helped to define the role of computed tomography imaging for otosclerosis, confirming that computed tomography is highly sensitive for diagnosis, yet limited in assessing cochlear endosteal involvement. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. SHEEP TEMPORAL BONE

    Directory of Open Access Journals (Sweden)

    Kesavan

    2016-03-01

    Full Text Available INTRODUCTION Human temporal bones are difficult to procure now a days due to various ethical issues. Sheep temporal bone is a good alternative due to morphological similarities, easy to procure and less cost. Many middle ear exercises can be done easily and handling of instruments is done in the procedures like myringoplasty, tympanoplasty, stapedotomy, facial nerve dissection and some middle ear implants. This is useful for resident training programme.

  10. Chondroblastoma of temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    Tanohta, K.; Noda, M.; Katoh, H.; Okazaki, A.; Sugiyama, S.; Maehara, T.; Onishi, S.; Tanida, T.

    1986-07-01

    The case of a 55-year-old female with chondroblastoma arising from the left temporal bone is presented. Although 10 cases of temporal chondroblastoma have been reported, this is the first in which plain radiography, pluridirectional tomography, computed tomography (CT) and angiography were performed. We discuss the clinical and radiological aspects of this rare tumor.

  11. Chondroblastoma of temporal bone

    International Nuclear Information System (INIS)

    Tanohta, K.; Noda, M.; Katoh, H.; Okazaki, A.; Sugiyama, S.; Maehara, T.; Onishi, S.; Tanida, T.

    1986-01-01

    The case of a 55-year-old female with chondroblastoma arising from the left temporal bone is presented. Although 10 cases of temporal chondroblastoma have been reported, this is the first in which plain radiography, pluridirectional tomography, computed tomography (CT) and angiography were performed. We discuss the clinical and radiological aspects of this rare tumor. (orig.)

  12. CT-scanning of ancient Greenlandic Inuit temporal bones

    International Nuclear Information System (INIS)

    Homoe, P.; Videbaek, H.

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones. (13 refs., 10 figs.)

  13. CT-scanning of ancient Greenlandic Inuit temporal bones

    Energy Technology Data Exchange (ETDEWEB)

    Homoe, P [Copenhagen Univ. (Denmark). Lab. of Biological Anthropology and Dept. of Otolaryngology, Head and Neck Surgery; Lynnerup, N [Copenhagen Univ., Lab. of Biological Anthropology and Univ. Inst. of Ferensic Medicine, Copenhagen (Denmark); Videbaek, H [Hvidovre Univ. Hospital, Copenhagen (Denmark). Dept. of Radiology

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal bones. The CT-scans showed sclerosing and obliteration of the air cells and even destruction of the cellular septae, and a high degree of irregularity of the cells. Sclerosing of the surrounding bone tissue was also found. The findings in one cranium were dubious and could both be regarded as a congenital malformation or an infection in infanthood. CT-scan confirms and even adds to the results of conventional X-ray of temporal bones making hypotheses of paleopathology more reliable. The findings also support the environmental theory of pneumatization of the air cell system in the temporal bones. (13 refs., 10 figs.).

  14. Aneurysmal bone cyst of the temporal bone

    International Nuclear Information System (INIS)

    Buxi, Tarvinder; Sud Seema; Vohra, Rakesh; Sud, Aditi; Singh, Satnam

    2004-01-01

    Aneurysmal bone cyst (ABC) of the temporal bone is rare. The nature of the underlying disorder that converted into the ABC might, however, be difficult to ascertain on imaging as well as on histopathology. The unusual CT and MRI findings in a case of ABC of the temporal bone are presented. This had transdural intracerebral spread with a large component of solid enhancing matrix but no peripheral calcific rim. The patient was an adult of 45 years with a history of headache for more than 1 year Copyright (2004) Blackwell Publishing Asia Pty Ltd

  15. Temporal bone trauma and imaging

    International Nuclear Information System (INIS)

    Turetschek, K.; Czerny, C.; Wunderbaldinger, P.; Steiner, E.

    1997-01-01

    Fractures of the temporal bone result from direct trauma to the temporal bone or occur as one component of a severe craniocerebral injury. Complications of temporal trauma are hemotympanon, facial nerve paralysis, conductive or sensorineur hearing loss, and leakage of cerebrospinal fluid. Erly recognition and an appropiate therapy may improve or prevent permanent deficits related to such complications. Only 20-30% of temporal bone fractures can be visualized by plain films. CT has displaced plain radiography in the investigation of the otological trauma because subtle bony details are best evaluated by CT which even can be reformatted in multiple projections, regardless of the original plane of scanning. Associated epidural, subdural, and intracerebral hemorrhagic lesions are better defined by MRI. (orig.) [de

  16. [Computed tomography of the temporal bone in diagnosis of chronic exudative otitis media].

    Science.gov (United States)

    Zelikovich, E I

    2005-01-01

    Computed tomography (CT) of the temporal bone was made in 37 patients aged 2 to 55 years with chronic exudative otitis media (CEOM). In 21 of them the pathology was bilateral. The analysis of 58 CT images has identified CT signs of chronic exudative otitis media. They include partial (17 temporary bones) or complete (38 temporal bones) block of the bone opening of the auditory tube, pneumatic defects of the tympanic cavity (58 temporal bones), pneumatic defects of the mastoid process and antrum (47 temporal bones), pathologic retraction of the tympanic membrane. The examination of the temporal bone detected both CT-signs of CEOM and other causes of hearing disorders in 14 patients (26 temporal bones) with CEOM symptoms and inadequately high hypoacusis. Among these causes were malformation of the auditory ossicula (n=5), malformation of the labynthine window (n=2), malformation of the middle and internal ear (n=4), a wide aqueduct of the vestibule, labyrinthine anomaly of Mondini's type (n=1), cochlear hypoplasia (n=4), stenosis of the internal acoustic meatuses (n=2). Sclerotic fibrous dysplasia was suggested in 2 temporal bones (by CT data). CT was repeated after surgical treatment of 10 patients (14 temporal bones) and visual assessment of tympanostomy results was made.

  17. Erythropoietic bone marrow in the pigeon: Development of its distribution and volume during growth and pneumatization of bones

    International Nuclear Information System (INIS)

    Schepelmann, K.

    1990-01-01

    During postnatal development of the pigeon, a large portion of the skeleton becomes pneumatized, displacing the hemopoietic bone marrow. The consequences of pneumatization on distribution and quantity of bone marrow as well as the availability of other sites for hemopoiesis have been investigated. Hemopoietic marrow of differently aged pigeons divided into five groups from 1 week posthatching (p.h.) up to 6 months p.h. was labeled with Fe-59 and examined by serial whole-body sections. Autoradiography and morphometry as well as scintillation counts of single bones and organs were also carried out. No sign of a reactivation of embryonic sites of erythropoiesis was found. Bone marrow weight and its proportion of whole-body weight increased during the first 4 weeks p.h. from 0.54% to 2.44% and decreased in the following months to about 1.0%. The developing bone marrow showed a progressive distribution during the first months of life, eventually being distributed proportionally over the entire skeleton, except for the skull. At the age of 6 months p.h. bone marrow had been displaced, its volume decreasing in correlation to increasing pneumaticity and conversion to fatty marrow. This generates the characteristic pattern of bone marrow distribution in adult pigeons, which shows hemopoietic bone marrow in ulna, radius, femur, tibiotarsus, scapula, furcula, and the caudal vertebrae

  18. Osteoradionecrosis of the temporal bone

    International Nuclear Information System (INIS)

    Fujimori, Masato; Koyama, Yukiko; Enomoto, Fuyuki; Ichikawa, Ginichiro

    2002-01-01

    We report a case of temporal bone necrosis that emerged after radiotherapy for epipharyngeal carcinoma performed 13 years ago. The patient was a 51-year-old male. His major complaint was left facial swelling. The patient underwent chemotherapy and radiotherapy (Co 60, 6120 rad), as the treatment of that period, for epipharyngeal carcinoma from September 30, 1986 to January 31, 1987. He also underwent lobectomy of the left temporal lobe in brain surgery for left temporal lobe necrosis in August, 1989. After that operation, we saw constriction in his left external acoustic meatus and continued the follow-up. On October 22, 1999 he felt a left facial swelling. We found skin defects and ulcer formation in the front part of his left ear. Although we administered an antiseptic and antibiotic to the diseased area, his condition did not improve. He was hospitalized for the purpose of undergoing medical treatment on January 6, 2000. We found extensive skin necrosis and defects in his left auricular area. The corrupted temporal bone reached the zygomatic, the bone department external acoustic meatus and the mastoid process was exposing. We performed debridement of the diseased area on January 19, 2000. On February 23, we performed reconstruction by left trapezius muscle flap after debridement once again. One year after the operation, the flap was completely incorporated. (author)

  19. Osteoradionecrosis of the temporal bone

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    Fujimori, Masato; Koyama, Yukiko; Enomoto, Fuyuki; Ichikawa, Ginichiro [Juntendo Univ., Tokyo (Japan). School of Medicine

    2002-08-01

    We report a case of temporal bone necrosis that emerged after radiotherapy for epipharyngeal carcinoma performed 13 years ago. The patient was a 51-year-old male. His major complaint was left facial swelling. The patient underwent chemotherapy and radiotherapy (Co 60, 6120 rad), as the treatment of that period, for epipharyngeal carcinoma from September 30, 1986 to January 31, 1987. He also underwent lobectomy of the left temporal lobe in brain surgery for left temporal lobe necrosis in August, 1989. After that operation, we saw constriction in his left external acoustic meatus and continued the follow-up. On October 22, 1999 he felt a left facial swelling. We found skin defects and ulcer formation in the front part of his left ear. Although we administered an antiseptic and antibiotic to the diseased area, his condition did not improve. He was hospitalized for the purpose of undergoing medical treatment on January 6, 2000. We found extensive skin necrosis and defects in his left auricular area. The corrupted temporal bone reached the zygomatic, the bone department external acoustic meatus and the mastoid process was exposing. We performed debridement of the diseased area on January 19, 2000. On February 23, we performed reconstruction by left trapezius muscle flap after debridement once again. One year after the operation, the flap was completely incorporated. (author)

  20. Air Space Proportion in Pterosaur Limb Bones Using Computed Tomography and Its Implications for Previous Estimates of Pneumaticity

    Science.gov (United States)

    Martin, Elizabeth G.; Palmer, Colin

    2014-01-01

    Air Space Proportion (ASP) is a measure of how much air is present within a bone, which allows for a quantifiable comparison of pneumaticity between specimens and species. Measured from zero to one, higher ASP means more air and less bone. Conventionally, it is estimated from measurements of the internal and external bone diameter, or by analyzing cross-sections. To date, the only pterosaur ASP study has been carried out by visual inspection of sectioned bones within matrix. Here, computed tomography (CT) scans are used to calculate ASP in a small sample of pterosaur wing bones (mainly phalanges) and to assess how the values change throughout the bone. These results show higher ASPs than previous pterosaur pneumaticity studies, and more significantly, higher ASP values in the heads of wing bones than the shaft. This suggests that pneumaticity has been underestimated previously in pterosaurs, birds, and other archosaurs when shaft cross-sections are used to estimate ASP. Furthermore, ASP in pterosaurs is higher than those found in birds and most sauropod dinosaurs, giving them among the highest ASP values of animals studied so far, supporting the view that pterosaurs were some of the most pneumatized animals to have lived. The high degree of pneumaticity found in pterosaurs is proposed to be a response to the wing bone bending stiffness requirements of flight rather than a means to reduce mass, as is often suggested. Mass reduction may be a secondary result of pneumaticity that subsequently aids flight. PMID:24817312

  1. Chondroblastoma of the temporal bone

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    Kobayashi, Yuko; Murakami, Ryusuke; Toba, Masahiro; Ichikawa, Taro [Dept. of Radiology, Nippon Medical School, Tokyo (Japan); Kanazawa, Ryuzaburo; Sanno, Naoko; Shimura, Toshiro [Dept. of Neurosurgery, Nippon Medical School, Tokyo (Japan); Sawada, Namie; Hosone, Masaru [Dept. of Pathology, Nippon Medical School, Tokyo (Japan); Kumazaki, Tatsuo [Dept. of Radiology, Nippon Medical School, Tokyo (Japan)

    2001-12-01

    A rare case of chondroblastoma arising from the temporal bone that occurred in a 60-year-old woman is reported. The tumor appeared well demarcated and osteolytic on the radiographs. CT scan clearly depicted marginal and central calcification in the tumor. MR imaging demonstrated two components in the tumor: a solid component with predominantly low signal intensities on both T1- and T2-weighted sequences, and a multilocular cystic component with T1- and T2-elongation and fluid-fluid levels on the T2-weighted images. Postcontrast MR imaging revealed marked enhancement in the solid component and the septa of the cystic component. (orig.)

  2. Schneiderian papilloma of the temporal bone

    NARCIS (Netherlands)

    van der Putten, L.; Bloemena, E.; Merkus, P.; Hensen, E.F.

    2013-01-01

    Temporal bone Schneiderian papilloma may present as a primary tumour originating from the middle ear and mastoid process, or an extension from sinonasal disease. Both forms are rare, this being only the 18th case of primary temporal bone Schneiderian papilloma described to date. Although the current

  3. Cerebrospinal otorrhoea--a temporal bone report.

    Science.gov (United States)

    Walby, A P

    1988-05-01

    Spontaneous cerebrospinal otorrhoea is a rare complication of a cholesteatoma. The histological findings in a temporal bone from such a case are reported. The cholesteatoma had eroded deeply through the vestibule into the internal auditory meatus.

  4. Giant osteoblastoma of temporal bone: case report

    Directory of Open Access Journals (Sweden)

    FIGUEIREDO EBERVAL GADELHA

    1998-01-01

    Full Text Available Benign osteoblastoma is an uncommon bone tumor accounting for approximately 1% of all bone tumors. There are only 35 cases of skull osteoblastoma reported in the literature. We describe the case of a 23 year old male with a giant osteoblastoma of temporal bone submitted to a total removal of the tumor after an effective embolization of all external carotid branches. The authors discuss diagnostic and management aspects of this uncommon skull tumor.

  5. Development of femoral bone fracture model simulating muscular contraction force by pneumatic rubber actuator.

    Science.gov (United States)

    Sen, Shin; Ando, Takehiro; Kobayashi, Etsuko; Miyamoto, Hideaki; Ohashi, Satoru; Tanaka, Sakae; Joung, Sanghyun; Park, Il-Hyung; Sakuma, Ichiro

    2014-01-01

    In femoral fracture reduction, orthopedic surgeons must pull distal bone fragments with great traction force and return them to their correct positions, by referring to 2D-fluoroscopic images. Since this method is physically burdensome, the introduction of robotic assistance is desirable. While such robots have been developed, adequate control methods have not yet been established because of the lack of experimental data. It is difficult to obtain accurate data using cadavers or animals because they are different from the living human body's muscle characteristics and anatomy. Therefore, an experimental model for simulating human femoral characteristics is required. In this research, human muscles are reproduced using a McKibben-type pneumatic rubber actuator (artificial muscle) to develop a model that simulates typical femur muscles using artificial muscles.

  6. High resolution CT of temporal bone trauma

    International Nuclear Information System (INIS)

    Youn, Eun Kyung

    1986-01-01

    Radiographic studies of the temporal bone following head trauma are indicated when there is cerebrospinal fluid otorrhea or rhinorrhoea, hearing loss, or facial nerve paralysis. Plain radiography displays only 17-30% of temporal bone fractures and pluridirectional tomography is both difficult to perform, particularly in the acutely ill patient, and less satisfactory for the demonstration of fine fractures. Consequently, high resolution CT is the imaging method of choice for the investigation of suspected temporal bone trauma and allows special resolution of fine bony detail comparable to that attainable by conventional tomography. Eight cases of temporal bone trauma examined at Korea General Hospital April 1985 through May 1986. The results were as follows: Seven patients (87%) suffered longitudinal fractures. In 6 patients who had purely conductive hearing loss, CT revealed various ossicular chain abnormality. In one patient who had neuro sensory hearing loss, CT demonstrated intract ossicular with a fracture nearing lateral wall of the lateral semicircular canal. In one patient who had mixed hearing loss, CT showed complex fracture.

  7. CT-scanning of ancient Greenlandic Inuit temporal bones

    DEFF Research Database (Denmark)

    Homøe, P; Lynnerup, N; Videbaek, H

    1992-01-01

    Additional morphological evidence of former infectious middle ear disease (IMED) was found by CT-scanning in 5 of 6 Greenlandic Inuit crania strongly suspected for former IMED due to earlier examination revealing either bilateral hypocellularity or asymmetry of the pneumatized area of the temporal...

  8. 3D Printed Pediatric Temporal Bone: A Novel Training Model.

    Science.gov (United States)

    Longfield, Evan A; Brickman, Todd M; Jeyakumar, Anita

    2015-06-01

    Temporal bone dissection is a fundamental element of otologic training. Cadaveric temporal bones (CTB) are the gold standard surgical training model; however, many institutions do not have ready access to them and their cost can be significant: $300 to $500. Furthermore, pediatric cadaveric temporal bones are not readily available. Our objective is to develop a pediatric temporal bone model. Temporal bone model. Tertiary Children's Hospital. Pediatric patient model. We describe the novel use of a 3D printer for the generation of a plaster training model from a pediatric high- resolution CT temporal bone scan of a normal pediatric temporal bone. Three models were produced and were evaluated. The models utilized multiple colors (white for bone, yellow for the facial nerve) and were of high quality. Two models were drilled as a proof of concept and found to be an acceptable facsimile of the patient's anatomy, rendering all necessary surgical landmarks accurately. The only negative comments pertaining to the 3D printed temporal bone as a training model were the lack of variation in hardness between cortical and cancellous bone, noting a tactile variation from cadaveric temporal bones. Our novel pediatric 3D temporal bone training model is a viable, low-cost training option for previously inaccessible pediatric temporal bone training. Our hope is that, as 3D printers become commonplace, these models could be rapidly reproduced, allowing for trainees to print models of patients before performing surgery on the living patient.

  9. Establishing a temporal bone laboratory: considerations for ENT specialist training.

    LENUS (Irish Health Repository)

    Fennessy, B G

    2012-02-01

    Cadaveric temporal bone dissection in a temporal bone laboratory is a vital component in training safe, competent otorhinolaryngologists. Recent controversies pertaining to organ retention have resulted in a more limited supply of temporal bones. Consequently, current trainees are dissecting far fewer bones than their consultants. We discuss the establishment of a temporal bone laboratory in the Department of Anatomy in the University College Cork, from the timely preparation and preservation of the tissue to its disposal. Comparisons are drawn between our experience and that of the United States training schemes. The temporal bone laboratory in Cork is the only one in existence in Ireland. The exposure and experience obtained by registrars rotating through Cork, has resulted in noticeable improvements in their operative abilities. The temporal bone laboratory remains a core component to training. It is hoped that this article may facilitate other units overcoming obstacles to establish a temporal bone laboratory.

  10. Temporal bone radiography using the orthopantomograph

    International Nuclear Information System (INIS)

    Tatezawa, T.

    1981-01-01

    Temporal bone radiographs obtained with an Orthopantomograph were compared with conventional radiographs. In acoustic neurinoma, cholesteatoma, otitis media, and middle fossa tumors, both methods demonstrated the abnormalities well. In two cases with lesions extending beyond the range of conventional projections, the broad orthopantomographic coverage was very valuable. Mastoid air cells, the mastoid process, petrous ridge, and internal auditory meatus were well demonstrated by both techniques. Orthopantomography was found to be superior in the demonstration of the petrous apex, while the superior semicircular canal was better demonstrated on the conventional views. Bilateral symmetry was particularly good and because of fewer films, radiation exposure was considerably less with orthopantomography. For many applications, orthopantomography is an adequate convenient substitute for conventional methods of examining the temporal bones

  11. CT of temporal bone - IV. inner ear

    International Nuclear Information System (INIS)

    Kwon, Jae Yoon; Sung, Kyu Bo; Youn, Eun Kyoung; Park, Youn Kyeung; Lee, Young Uk

    1990-01-01

    Temporal bone CT was done in 697 patients from April 1985 to October 1989. The abnormal findings were seen in 453 patients, which were chronic otitis media in 355 patients, fracture in 49 patients and congenital anomaly in 44 patients, etc. The abnormal findings of inner ear were observed on 46 patients. The results were summarized as follows : 1. The incidence of inner ear involvement by chronic otitis media was 7.3% (26/355 : labyrinthine fistula in 17 patients, labyrinthitis ossificans in 9 patients). Labyrinthine fistula was most commonly located on lateral semicircular canal (15/17, 88.2%). 2. Fusion of vestibule with lateral semicircular canal and formation of common cavity was demonstrated incidentally in 5 patients (0.7% of total number of temporal bone CT), and bilateral in 3 patients. 3. The incidence of inner ear anomaly in congenital ear anomaly was 11.4% (5/44). All cases were bilateral and three patients showed associated middle ear anomaly. 4. The incidence of involvement of bony labyrinth in temporal bone fracture was 10.2% (5/49). Labyrinthine fracture was seen all patients of transverse(3) and mixed fracture(1). In longitudinal fracture, labyrinthine fracture was seen in 2.2% (1/45). 5. Others were traumatic labyrinthitis ossificans(1), intracanalicular acoustic neuroma(3) and facial nerve neuroma(1)

  12. CT-diagnosis of temporal bone trauma

    Energy Technology Data Exchange (ETDEWEB)

    Valavanis, A.; Stuckmann, G.; Antonucci, F.; Schubiger, O.

    1986-02-01

    73 patients with 78 fractures of the temporal bone were examined by high-resolution computed tomography (CT). Analysis of the CT-findings disclosed 55 longitudinal, 12 transverse, 8 combined and 3 atypical fractures. For determination of the fracture type, axial sections usually proved sufficient. However, for precise topographic analysis of the course of the fracture additional coronal sections were necessary in most of the cases. In the radiologic evaluation of temporal bone fractures detection of associated. Complications is clinically important since these can be surgically corrected. In this series 20 lesions of the ossicular chain were demonstrated by the combined performance of axial and coronal sections and sagittal reformations. High resolution CT demonstrated a lesion of the facial nerve canal in 79% of a patient group with traumatic facial nerve palsy. The most frequent site of injury of the facial nerve canal was the region of the geniculate ganglion. With the use of metrizaminde-CT-cisternography the site of cerebrospinal fluid leakage was demonstrated in 7 of 9 patients with liquorrhea. It is concluded that high-resolution CT is the radiologic method of choice for both topographic evaluation of temporal bone fractures and detection and precise localization of fracture-complications. (orig.).

  13. Study of a temporal bone of Homo heildelbergensis.

    Science.gov (United States)

    Urquiza, Rafael; Botella, Miguel; Ciges, Miguel

    2005-05-01

    The characteristic features of the Hh specimen conformed to those of other Pleistocene human fossils, indicating strong cranial structures and a heavy mandible. The mastoid was large and suggested a powerful sternocleidomastoid muscle. The inner ear and tympanic cavities were similar in size and orientation, suggesting that their functions were probably similar. Our observations suggest that the left ear of this Hh specimen was healthy. The large canaliculo-fenestral angle confirms that this ancestor was bipedal. It also strongly suggests that Hh individuals were predisposed to develop certain pathologies of the labyrinth capsule associated with bipedalism, in particular otosclerosis. We studied a temporal bone of Homo heidelbergensis (Hh) in order to investigate the clinical and physiological implications of certain morphological features, especially those associated with the evolutionary reorganization of the inner ear. The bone, found in a breach of a cave near MAáaga in southern Spain, together with Middle Upper Pleistocene faunal remains, is >300000 years old. Four analytical methods were employed. A 3D high-resolution surface laser scan was used for anatomical measurements. For the sectional analysis of the middle and inner ears of Hh we used high-resolution CT, simultaneously studying a normal temporal bone from Homo sapiens sapiens (Hss). To study the middle and inner ear spaces we used 3D reconstruction CT preceded by an intra-bone air shielding technique. To examine the tympanic cavities and measure the canaliculo fenestral angle, we used a special minimally invasive endoscopic procedure. The surface, sectional and 3D CT examinations showed that the Hh specimen was generally more robust and larger than the Hss specimen. It had a large glenoid fossa. The external meatus was wide and deep. The middle ear, and especially the mastoid, was large and widely pneumatized. There were no appreciable differences in the position and size of the labyrinthine spaces

  14. Sclerosteosis involving the temporal bone: histopathologic aspects.

    Science.gov (United States)

    Nager, G T; Hamersma, H

    1986-01-01

    Sclerosteosis is a rare, potentially lethal, autosomal recessive, progressive craniotubular sclerosing bone dysplasia with characteristic facial and skeletal features. The temporal bone changes include a marked increase in overall size, extensive sclerosis, narrowing of the external auditory canal, and severe constriction of the internal auditory meatus, fallopian canal, eustachian tube, and middle ear cleft. Attenuation of the bony canals of the 9th, 10th, and 11th cranial nerves, reduction in size of the internal carotid artery, and severe obliteration of the sigmoid sinus and jugular bulb also occur. Loss of hearing, generally bilateral, is a frequent symptom. It often manifests in early childhood and initially is expressed as sound conduction impairment. Later, a sensorineural hearing loss and loss of vestibular nerve function often develop. Impairment of facial nerve function is another feature occasionally present at birth. In the beginning, a unilateral intermittent facial weakness may occur which eventually progresses to a bilateral permanent facial paresis. The histologic examination of the temporal bones from a patient with sclerosteosis explains the mechanisms involved in the progressive impairment of sound conduction and loss of cochlear, vestibular, and facial nerve function. There is a decrease of the arterial blood supply to the brain and an obstruction of the venous drainage from it. The histopathology reveals the obstacles to decompression of the middle ear cleft, ossicular chain, internal auditory and facial canals, and the risks, and in many instances the contraindications, to such procedures. On the other hand, decompression of the sigmoid sinus and jugular bulb should be considered as an additional life-saving procedure in conjunction with the prophylactic craniotomy recommended in all adult patients.

  15. Computed tomography of temporal bone fractures and temporal region anatomy in horses.

    Science.gov (United States)

    Pownder, S; Scrivani, P V; Bezuidenhout, A; Divers, T J; Ducharme, N G

    2010-01-01

    In people, specific classifications of temporal bone fractures are associated with clinical signs and prognosis. In horses, similar classifications have not been evaluated and might be useful establishing prognosis or understanding pathogenesis of certain types of trauma. We hypothesized associations between temporal bone fracture location and orientation in horses detected during computed tomography (CT) and frequency of facial nerve (CN7) deficit, vestibulocochlear nerve (CN8) deficit, or temporohyoid osteoarthropathy (THO). Complex temporal region anatomy may confound fracture identification, and consequently a description of normal anatomy was included. All horses undergoing temporal region CT at our hospital between July 1998 and May 2008. Data were collected retrospectively, examiners were blinded, and relationships were investigated among temporal bone fractures, ipsilateral THO, ipsilateral CN7, or ipsilateral CN8 deficits by Chi-square or Fischer's exact tests. Seventy-nine horses had CT examinations of the temporal region (158 temporal bones). Sixteen temporal bone fractures were detected in 14 horses. Cranial nerve deficits were seen with fractures in all parts of the temporal bone (petrosal, squamous, and temporal) and, temporal bone fractures were associated with CN7 and CN8 deficits and THO. No investigated fracture classification scheme, however, was associated with specific cranial nerve deficits. Without knowledge of the regional anatomy, normal structures may be mistaken for a temporal bone fracture or vice versa. Although no fracture classification scheme was associated with the assessed clinical signs, simple descriptive terminology (location and orientation) is recommended for reporting and facilitating future comparisons.

  16. European status on temporal bone training

    DEFF Research Database (Denmark)

    Frithioff, Andreas; Sørensen, Mads Sølvsten; Andersen, Steven Arild Wuyts

    2018-01-01

    laboratory facilities for training seems to be decreasing. Alternatives to traditional training can consist of drilling artificial models made of plaster or plastic but also virtual reality (VR) simulation. Nevertheless, the integration and availability of these alternatives into specialist training programs...... training modality. CONCLUSIONS: VR simulation and artificial models are reported to be used at many leading training departments already. Decreasing availability of cadavers, lower costs of VR simulation and artificial models, in addition to established evidence for a positive effect on the trainees......' competency, were reported as the main reasons. Most remaining departments expect to implement VR simulation and artificial models for temporal bone training into their residency programs in the near future....

  17. Pneumatically-powered hand tool used for cutting bolts during bone-fixing in surgery

    NARCIS (Netherlands)

    Cool, J.C.; Rijnsaardt, K.A.

    1996-01-01

    Abstract of NL 1000849 (C2) The tool has at least one pneumatic motor (1a, 1b), transmission (2) and regulator. The motor(s) can be of the piston and cylinder type producing reciprocating motion or of the rotary type. The tool is powered by a commercially-available gas cylinder containing 16g of CO2

  18. Chemodectomas arising in temporal bone structures

    International Nuclear Information System (INIS)

    Dickens, W.J.; Million, R.R.; Cassisi, N.J.; Singleton, G.T.

    1982-01-01

    Eighteen patients with chemodectomas arising in temporal bone structures were evaluated and treated at the University of Florida. Seventeen patients have each been followed a minimum of 3 years. Patients were retrospectively staged as having ''local'' or ''advanced'' disease, depending on the presence or absence of bone destruction and/or cranial nerve involvement. Fourteen of the patients received radiation therapy as all or part of their therapy; 6 patients were treated with radiation therapy alone, 3 patients were irradiated immediately postoperatively for residual disease, and 5 patients had radiation therapy for recurrence after operation. They were treated with cobalt-60 radiation with doses ranging from 3760 to 5640 rad. All irradiated patients demonstrated evidence of tumor regression, and none have had tumor recurrence with followup of 3-12 years. Of the 8 patients with cranial nerve paralysis prior to therapy, 5 had return of function of 1 or more cranial nerves. One of 6 patients treated initially with radiation therapy had a complication, while 6 of 8 patients irradiated postoperatively had complications. None of the complications were fatal. Three patients treated by operation for early disease limited to the hypotympanum had the disease controlled for 11-12 years. Guidelines for the selection of initial therapy are discussed

  19. Radiation injury to the temporal bone

    International Nuclear Information System (INIS)

    Guida, R.A.; Finn, D.G.; Buchalter, I.H.; Brookler, K.H.; Kimmelman, C.P.

    1990-01-01

    Osteoradionecrosis of the temporal bone is an unusual sequela of radiation therapy to the head and neck. Symptoms occur many years after the radiation is administered, and progression of the disease is insidious. Hearing loss (sensorineural, conductive, or mixed), otalgia, otorrhea, and even gross tissue extrusion herald this condition. Later, intracranial complications such as meningitis, temporal lobe or cerebellar abscess, and cranial neuropathies may occur. Reported here are five cases of this rare malady representing varying degrees of the disease process. They include a case of radiation-induced necrosis of the tympanic ring with persistent squamous debris in the external auditory canal and middle ear. Another case demonstrates the progression of radiation otitis media to mastoiditis with bony sequestration. Further progression of the disease process is seen in a third case that evolved into multiple cranial neuropathies from skull base destruction. Treatment includes systemic antibiotics, local wound care, and debridement in cases of localized tissue involvement. More extensive debridement with removal of sequestrations, abscess drainage, reconstruction with vascularized tissue from regional flaps, and mastoid obliteration may be warranted for severe cases. Hyperbaric oxygen therapy has provided limited benefit

  20. Chondrosarcoma of the temporal bone: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Park, Man Soo; Lee, Sang Youl; Chung, Jae Gul; Lee, Deok Hee; Jung, Seung Mun; Ryu, Dae Sik [Kang Nung Hospital, Ulsan Univ. Kangnung (Korea, Republic of)

    2001-07-01

    Chondrosarcoma of the temporal bone is a rare lesion. Clinically it has been confused with chordoma, glomus jugulare tumor and meningioma, among other conditions, and due to its anatomic location, cranial nerve palsy is frequently observed. We report a case involving a 50-year-old woman with chondrosarcoma of the temporal bone.

  1. Chondrosarcoma of the temporal bone: a case report

    International Nuclear Information System (INIS)

    Park, Man Soo; Lee, Sang Youl; Chung, Jae Gul; Lee, Deok Hee; Jung, Seung Mun; Ryu, Dae Sik

    2001-01-01

    Chondrosarcoma of the temporal bone is a rare lesion. Clinically it has been confused with chordoma, glomus jugulare tumor and meningioma, among other conditions, and due to its anatomic location, cranial nerve palsy is frequently observed. We report a case involving a 50-year-old woman with chondrosarcoma of the temporal bone

  2. Temporal Bone Fracture Causing Superior Semicircular Canal Dehiscence

    Directory of Open Access Journals (Sweden)

    Kevin A. Peng

    2014-01-01

    Full Text Available Importance. Superior semicircular canal dehiscence (SCD is a third window lesion of the inner ear causing symptoms of vertigo, autophony, tinnitus, and hearing loss. A “two-hit” hypothesis has traditionally been proposed, whereby thinly developed bone overlying the superior canal is disrupted by a sudden change in intracranial pressure. Although the symptoms of SCD may be precipitated by head injury, no previous reports have described a temporal bone fracture directly causing SCD. Observations. Two patients sustained temporal bone fractures after closed head trauma, and developed unilateral otologic symptoms consistent with SCD. In each instance, computed tomography imaging revealed fractures extending through the bony roof of the superior semicircular canal. Conclusions and Relevance. Temporal bone fractures, which are largely treated nonoperatively, have not previously been reported to cause SCD. As it is a potentially treatable entity, SCD resulting from temporal bone fracture must be recognized as a possibility and diagnosed promptly if present.

  3. Cadaveric Temporal Bone Dissection: Is It Obsolete Today?

    Directory of Open Access Journals (Sweden)

    Naik, Sulabha M.

    2014-01-01

    Full Text Available Introduction Traditionally, surgical training in otology, is imparted by dissecting harvested human cadaveric temporal bones. However, maintenance of a cadaveric temporal bone laboratory is expensive and carries risk of exposure to infection. In recent times, other modalities of training are gaining ground and are likely to eventually replace cadaveric temporal bone dissection altogether. Objectives Other alternative methods of training are emerging. New technology like simulation and virtual reality as high-fidelity, safer alternatives, are making rapid strides as teaching tools. Other options are the use of animal temporal bones as teaching tools. The advantages of these are compared. Data Synthesis None of these modalities can replicate the innumerable anatomical variations which are a characteristic feature of the human temporal bone. A novice surgeon not only needs exposure to surgical anatomy and it's variations but also needs to develop hand-eye coordination skills to gain expertise. Conclusion Deliberate practice on human cadaveric temporal bones only, will confer both mastery in anatomy and surgical technique. The human cadaveric temporal bone is ideal simulator for training in otology.

  4. CT features of fibrous dysplasia of the temporal bone

    International Nuclear Information System (INIS)

    Charrada-Ben Farhat, L.; Bourkhis, S.; Ben Yaacoub, I.; Dali, N.; Askri, A.; Hendaoui, L.

    2006-01-01

    Fibrous dysplasia is characterized by a progressive replacement of normal bone elements by fibrous tissue. The temporal bone is rarely involved. In this location, complications such as facial deformity, conductive hearing loss and facial peripheral neural involvement can occur. Positive diagnosis can be established with computerized tomography which also enables assessment of extension and detection of complications. We report a case of a 27-year-old man with extensive fibrous dysplasia of the right temporal bone presenting with conductive hearing loss secondary to progressive stenosis of the external auditory canal. Computerized tomography of the temporal region was performed. (authors)

  5. The relationship between presbycusis and mastoid pneumatization.

    Science.gov (United States)

    Pata, Yavuz Selim; Akbaş, Yucel; Unal, Murat; Duce, Meltem Nass; Akbaş, Tugana; Micozkadioğlu, Deniz

    2004-02-29

    Presbycusis is defined as the natural hearing loss accompanying aging, caused by degenerative changes in the inner ear. The etiology of presbycusis is uncertain. However, it would appear that a complex genetic cause is most likely. The determinants of mastoid size continue to be controversial. One of the pneumatization theories is the hereditary theory. In this study, the possible relationship between presbycusis and the extent of mastoid pneumatization was investigated. This study was carried out on 21 patients with presbycusis and 21 normal subjects of similar ages. The pneumatized volume was measured by computerized tomography. The temporal bone was scanned at 2 mm thickness intervals. Exposure (kV 130, mA105). The scan plane was parallel to the orbitomeatal line and the CT images covered the entire mastoid region. The average mastoid pneumatization in presbycusis group was 6.08 +/- 2.52 cm(3) in the right ear and 6.19 +/- 2.93 cm(3) in the left ear. However, in the control group it was 4.69 +/- 3.17 cm(3) in the right ear (p=0.12) and 5.10 +/- 3.49 cm(3) in the left ear (p=0.28). No significant difference was found between the presbycusis patients and normal subjects in terms of the volume of mastoid pneumatization.

  6. Bone scintigraphy in the diagnosis of fracture and infection of the temporal bone

    International Nuclear Information System (INIS)

    Djupesland, G.; Nakken, K.F.; Mueller, C.; Skjoerten, F.; Roehrt, T.; Eldevik, P.

    1983-01-01

    The sensivit of Tc99m-MDP-bone-scintiscanning in the diagnosis of temporal bone fracture was found to that of conventional radiography if the patients were examined 10 days after the trauma. Temporal bone osteomyelitis with concomitant moderate osteosclerosis was demonstrated by bone scintigraphy in 5 cases of mastoiditis with atypical symptoms. A case of apicitis was for the first time demonstrated by scintigraphy. A low sensivity of 67 Ga-scintigraphy was demonstrated by positive Tc99m-bone-scintigraphy and negative 67 Ga-scintigraphy in a patient with atypical mastoiditis. Tc99m-scintigraphy was negative in 5 cases of otitis media suppurative and in 3 cases of otitis media chronica cum cholesteatoma, all with slight degree of osteosclerosis in the mastoid. The sensitivity of Tc99m-bone-scintigraphy in fracture and osteomyelitis of the temporal bone seems to be a function of the amount of reactive new bone formed. (Authors)

  7. Temporal bone paragangliomas: 15 years experience

    Directory of Open Access Journals (Sweden)

    Mehmet Düzlü

    Full Text Available Abstract Introduction Temporal bone paragangliomas (TBPs are benign tumors arising from neural crest cells located along the jugular bulbus and the tympanic plexus. In general surgical excision, radiotherapy and wait-and-scan protocols are the main management modalities for TBPs. Objective In this paper we aim to present our clinical experience with TBPs and to review literature data. Methods The patients who were operated for tympanomastoid paraganglioma (TMP or tympanojugular paraganglioma (TJP in our clinic in the last 15 years were enrolled in the study. A detailed patient's charts review was performed retrospectively. Results There were 18 (52.9% cases with TMPs and 16 (47.1% cases with TJPs, a total of 34 patients operated for TBPs in this time period. The mean age was 50.3 ± 11.7 (range 25-71 years. The most common presenting symptoms were tinnitus and hearing loss for both TMPs and TJPs. Gross total tumor resection was achieved in 17 (94.4% and 10 (62.5% cases for TMPs and TJPs, respectively. Five patients (31.2% with TJP experienced facial palsy following the operation. For all the patients the mean follow-up period was 25.8 months (range 4-108 months. Conclusion In conclusion, based on our findings and literature review, total surgical excision alone or with preoperative embolization is the main treatment modality for TBPs. However radiotherapy, observation protocol and subtotal resection must be considered in cases of preoperative functioning cranial nerves, large tumors and advanced age.

  8. Temporal bone paragangliomas: 15 years experience.

    Science.gov (United States)

    Düzlü, Mehmet; Tutar, Hakan; Karamert, Recep; Karaloğlu, Furkan; Şahin, Muammer Melih; Göcek, Mehmet; Uğur, Mehmet Birol; Göksu, Nebil

    2016-12-08

    Temporal bone paragangliomas (TBPs) are benign tumors arising from neural crest cells located along the jugular bulbus and the tympanic plexus. In general surgical excision, radiotherapy and wait-and-scan protocols are the main management modalities for TBPs. In this paper we aim to present our clinical experience with TBPs and to review literature data. The patients who were operated for tympanomastoid paraganglioma (TMP) or tympanojugular paraganglioma (TJP) in our clinic in the last 15 years were enrolled in the study. A detailed patient's charts review was performed retrospectively. There were 18 (52.9%) cases with TMPs and 16 (47.1%) cases with TJPs, a total of 34 patients operated for TBPs in this time period. The mean age was 50.3± 11.7 (range 25-71 years). The most common presenting symptoms were tinnitus and hearing loss for both TMPs and TJPs. Gross total tumor resection was achieved in 17 (94.4%) and 10 (62.5%) cases for TMPs and TJPs, respectively. Five patients (31.2%) with TJP experienced facial palsy following the operation. For all the patients the mean follow-up period was 25.8 months (range 4-108 months). In conclusion, based on our findings and literature review, total surgical excision alone or with preoperative embolization is the main treatment modality for TBPs. However radiotherapy, observation protocol and subtotal resection must be considered in cases of preoperative functioning cranial nerves, large tumors and advanced age. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  9. Post traumatic facial nerve palsy without temporal bone fracture

    International Nuclear Information System (INIS)

    Scuotto, A.; Cappabianca, S.; Capasso, R.; Porto, A.; D'Oria, S.; Rotondo, M.

    2016-01-01

    Facial nerve injury following head trauma is a frequent event with or without temporal bone fractures. Computed tomography is the imaging modality of choice for assessing the possible bone disruption of the facial nerve canal. Magnetic resonance is helpful in presence of a facial nerve paralysis, unexplained by computed tomography findings. We present a case of delayed post-traumatic facial nerve palsy without radiological evidence of temporal bone fractures, in which magnetic resonance was crucial for diagnosing the nerve impairment. Radiological findings in accordance both with electrodiagnostic tests and clinical presentation suggested the successful conservative management. - Highlights: • Facial nerve is more prone to damage than any other cranial nerve after trauma. • Facial nerve trauma is usually associated with temporal bone fractures. • MRI is mandatory in case of no evidence of bone disruption at CT.

  10. Surgical anatomy of the temporal bone: an atlas

    International Nuclear Information System (INIS)

    Chan, L.L.; Manolidis, S.; Taber, K.H.; Hayman, L.A.

    2001-01-01

    This atlas demonstrates the usefulness of reconstructed high-resolution CT for planning temporal bone surgery. The first part focuses on a sagittal plane, the second on a rotated longitudinal plane, and the third on a rotated transverse plane. We believe knowledge of temporal bone anatomy in these planes facilitates surgical planning by showing anatomic relationships and providing a customized map for each patient. This decreases the likelihood of surgical mishap and improves teaching. (orig.)

  11. Congenital external auditory canal atresia and stenosis: temporal bone CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Hoon; Kim, Bum Soo; Jung, So Lyung; Kim, Young Joo; Chun, Ho Jong; Choi, Kyu Ho; Park, Shi Nae [College of Medicine, Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2002-04-01

    To determine the computed tomographic (CT) findings of atresia and stenosis of the external auditory canal (EAC), and to describe associated abnormalities in surrounding structures. We retrospectively reviewed the axial and coronal CT images of the temporal bone in 15 patients (M:F=8:7;mean age, 15.8 years) with 16 cases of EAC atresia (unilateral n=11, bilateral n=1) and EAC stenosis (unilateral n=3). Associated abnormalities of the EAC, tympanic cavity, ossicles, mastoid air cells, eustachian tube, facial nerve course, mandibular condyle and condylar fossa, sigmoid sinus and jugular bulb, and the base of the middle cranial fossa were evaluated. Thirteen cases of bony EAC atresia (one bilateral), with an atretic bony plate, were noted, and one case of unilateral membranous atresia, in which a soft tissue the EAC. A unilateral lesion occurred more frequently on the right temporal bone (n=8, 73%). Associated abnormalities included a small tympanic cavity (n=8, 62%), decreased mastoid pneumatization (n=8, 62%), displacement of the mandibular condyle and the posterior wall of the condylar fossa (n=7, 54%), dilatation of the Eustachian tube (n=7, 54%), and inferior displacement of the temporal fossa base (n=8, 62%). Abnormalities of ossicles were noted in the malleolus (n=12, 92%), incus (n=10, 77%) and stapes (n=6, 46%). The course of the facial nerve was abnormal in four cases, and abnormality of the auditory canal was noted in one. Among three cases of EAC stenosis, ossicular aplasia was observed in one, and in another the location of the mandibular condyle and condylar fossa was abnormal. In the remaining case there was no associated abnormality. Atresia of the EAC is frequently accompanied by abnormalities of the middle ear cavity, ossicles, and adjacent structures other than the inner ear. For patients with atresia and stenosis of this canal, CT of the temporal bone is essentially helpful in evaluating these associated abnormalities.

  12. IgG4-Related Disease of Bilateral Temporal Bones.

    Science.gov (United States)

    Li, Lilun; Ward, Bryan; Cocks, Margaret; Kheradmand, Amir; Francis, Howard W

    2017-03-01

    IgG4-related disease (IgG4-RD) is an idiopathic inflammatory condition that causes pseudotumor formation in single or multiple organs, including those of the head and neck. Temporal bone involvement is rare, with only 3 cases of unilateral temporal bone IgG4-RD described in the literature. We report the first known case of IgG4-RD of bilateral temporal bones and describe its clinical presentation, diagnosis, and treatment. The patient was a 52-year-old man with latent tuberculosis (TB) who presented with a 10-year history of bilateral profound hearing loss and vestibular dysfunction. Computed tomography and magnetic resonance imaging demonstrated bilateral labyrinthine destruction with invasion of the posterior fossa. Immunoglobulin level testing showed elevated total serum IgG levels with normal IgG4 levels. Bilateral mastoidectomies were performed, with biopsy samples demonstrating IgG4 staining with IgG4-positive plasma cells up to 40/HPF (high power field) on the right and 20/HPF on the left, consistent with bilateral IgG4-RD. IgG4-RD of bilateral temporal bones presents with chronic and progressive bilateral hearing loss and vestibular dysfunction. Clinical presentation and radiologic findings are nonspecific, and definitive diagnosis must be made with histopathology and immunostaining. Corticosteroids are therapeutic, but surgical resection may be necessary for temporal bone IgG4-RD to improve long-term remission.

  13. Anatomical study of the pigs temporal bone by microdissection.

    Science.gov (United States)

    Garcia, Leandro de Borborema; Andrade, José Santos Cruz de; Testa, José Ricardo Gurgel

    2014-01-01

    Initial study of the pig`s temporal bone anatomy in order to enable a new experimental model in ear surgery. Dissection of five temporal bones of Sus scrofa pigs obtained from UNIFESP - Surgical Skills Laboratory, removed with hole saw to avoid any injury and stored in formaldehyde 10% for better conservation. The microdissection in all five temporal bone had the following steps: inspection of the outer part, external canal and tympanic membrane microscopy, mastoidectomy, removal of external ear canal and tympanic membrane, inspection of ossicular chain and middle ear. Anatomically it is located at the same position than in humans. Some landmarks usually found in humans are missing. The tympanic membrane of the pig showed to be very similar to the human, separating the external and the middle ear. The middle ear`s appearance is very similar than in humans. The ossicular chain is almost exactly the same, as well as the facial nerve, showing the same relationship with the lateral semicircular canal. The temporal bone of the pigs can be used as an alternative for training in ear surgery, especially due the facility to find it and its similarity with temporal bone of the humans.

  14. Intra-temporal facial nerve centerline segmentation for navigated temporal bone surgery

    NARCIS (Netherlands)

    Voormolen, E.H.J.; Stralen, van M.; Woerdeman, P.A.; Pluim, J.P.W.; Noordmans, H.J.; Regli, L.; Berkelbach van der Sprenkel, J.W.; Viergever, M.A.; Wong, K.H.; Holmes III, D.R.

    2011-01-01

    Approaches through the temporal bone require surgeons to drill away bone to expose a target skull base lesion while evading vital structures contained within it, such as the sigmoid sinus, jugular bulb, and facial nerve. We hypothesize that an augmented neuronavigation system that continuously

  15. A case of osteoradionecrosis of the temporal bone

    International Nuclear Information System (INIS)

    Okuno, Hideji; Saito, Yozo; Katori, Kimiaki; Hata, Yuko

    1983-01-01

    A case of osteoradionecrosis of the temporal bone was described. The patient had received radiotherapy for her nasopharyngeal cancer. Her symptoms of osteoradionecrosis of the temporal bone, otorrhea and earache, first appeared 5 years after her radiotherapy. Since then, conservative therapy was continued for 5 years, but her symptoms were not controlled with it. Ten years after her radiotherapy, the symptoms worsened rapidly, and the pain became intolerable, which necessitated mastoidectomy. After this surgery, she was free of symptoms until now. Based on this case, we discussed the pathologic, diagnostic and therapeutic aspects of osteoradionecrosis of the temporal bone. Emphasis was placed on the possibility of the occurence of this pathologic condition among all the patients who have received radiotherapy for malignant tumors of the head and neck or brain. (author)

  16. Massive Cerebrospinal Fluid Leak of the Temporal Bone

    Directory of Open Access Journals (Sweden)

    Giannicola Iannella

    2016-01-01

    Full Text Available Cerebrospinal fluid (CSF leakage of the temporal bone region is defined as abnormal communications between the subarachnoidal space and the air-containing spaces of the temporal bone. CSF leak remains one of the most frequent complications after VS surgery. Radiotherapy is considered a predisposing factor for development of temporal bone CSF leak because it may impair dural repair mechanisms, thus causing inadequate dural sealing. The authors describe the case of a 47-year-old man with a massive effusion of CSF which extended from the posterior and lateral skull base to the first cervical vertebrae; this complication appeared after a partial enucleation of a vestibular schwannoma (VS with subsequent radiation treatment and second operation with total VS resection.

  17. Conventional diagnostic imaging of the temporal bone. A historical review

    International Nuclear Information System (INIS)

    Canigiani, G.

    1997-01-01

    The Viennese Medical School played an important role in the development of radiological examinations and signs of the temporal bone with conventional X-rays. Famous pioneers include E.G. Mayer (1893-1969) and L. Psenner (1910-1986). Nowadays conventional X-rays and tomography have lost their important role in diagnostic radiology of the temporal bone, but the basic principles established in those early years of radiology are still used now. This statement is correct not only for conventional X-rays, but particularly for 'poly'-tomography in comparison with CT. (orig.) [de

  18. Bone Density Development of the Temporal Bone Assessed by Computed Tomography.

    Science.gov (United States)

    Takahashi, Kuniyuki; Morita, Yuka; Ohshima, Shinsuke; Izumi, Shuji; Kubota, Yamato; Horii, Arata

    2017-12-01

    The temporal bone shows regional differences in bone development. The spreading pattern of acute mastoiditis shows age-related differences. In infants, it spreads laterally and causes retroauricular swelling, whereas in older children, it tends to spread medially and causes intracranial complications. We hypothesized that bone maturation may influence the spreading pattern of acute mastoiditis. Eighty participants with normal hearing, aged 3 months to 42 years, participated in this study. Computed tomography (CT) values (Hounsfield unit [HU]) in various regions of the temporal bone, such as the otic capsule (OC), lateral surface of the mastoid cavity (LS), posterior cranial fossa (PCF), and middle cranial fossa (MCF), were measured as markers of bone density. Bone density development curves, wherein CT values were plotted against age, were created for each region. The age at which the CT value exceeded 1000 HU, which is used as an indicator of bone maturation, was calculated from the development curves and compared between the regions. The OC showed mature bone at birth, whereas the LS, PCF, and MCF showed rapid maturation in early childhood. However, there were significant regional differences in the ages of maturation: 1.7, 3.9, and 10.8 years for the LS, PCF, and MCF, respectively. To our knowledge, this is the first report to show regional differences in the maturation of temporal bone, which could partly account for the differences in the spreading pattern of acute mastoiditis in individuals of different ages.

  19. A Novel Temporal Bone Simulation Model Using 3D Printing Techniques.

    Science.gov (United States)

    Mowry, Sarah E; Jammal, Hachem; Myer, Charles; Solares, Clementino Arturo; Weinberger, Paul

    2015-09-01

    An inexpensive temporal bone model for use in a temporal bone dissection laboratory setting can be made using a commercially available, consumer-grade 3D printer. Several models for a simulated temporal bone have been described but use commercial-grade printers and materials to produce these models. The goal of this project was to produce a plastic simulated temporal bone on an inexpensive 3D printer that recreates the visual and haptic experience associated with drilling a human temporal bone. Images from a high-resolution CT of a normal temporal bone were converted into stereolithography files via commercially available software, with image conversion and print settings adjusted to achieve optimal print quality. The temporal bone model was printed using acrylonitrile butadiene styrene (ABS) plastic filament on a MakerBot 2x 3D printer. Simulated temporal bones were drilled by seven expert temporal bone surgeons, assessing the fidelity of the model as compared with a human cadaveric temporal bone. Using a four-point scale, the simulated bones were assessed for haptic experience and recreation of the temporal bone anatomy. The created model was felt to be an accurate representation of a human temporal bone. All raters felt strongly this would be a good training model for junior residents or to simulate difficult surgical anatomy. Material cost for each model was $1.92. A realistic, inexpensive, and easily reproducible temporal bone model can be created on a consumer-grade desktop 3D printer.

  20. Papercraft temporal bone in the first step of anatomy education.

    Science.gov (United States)

    Hiraumi, Harukazu; Sato, Hiroaki; Ito, Juichi

    2017-06-01

    (1) To compare temporal bone anatomy comprehension taught to speech therapy students with or without a papercraft model. (2) To explore the effect of papercraft simulation on the understanding of surgical approaches in first-year residents. (1) One-hundred and ten speech therapy students were divided into three classes. The first class was taught with a lecture only. The students in the second class were given a lecture and a papercraft modeling task without instruction. The third class modeled a papercraft with instruction after the lecture. The students were tested on their understanding of temporal bone anatomy. (2) A questionnaire on the understanding of surgical approaches was completed by 10 residents before and after the papercraft modeling. The papercraft models were cut with scissors to simulate surgical approaches. (1) The average scores were 4.4/8 for the first class, 4.3/8 for the second class, and 6.3/8 for the third class. The third class had significantly better results than the other classes (ppapercraft modeling and cutting were 2.6/7 and 4.9/7, respectively. The numerical rating scale score significantly improved (ppapercraft temporal bone model is effective in the first step of learning temporal bone anatomy and surgical approaches. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Craniofacial and temporal bone CT findings in cleidocranial dysplasia

    International Nuclear Information System (INIS)

    Gonzalez, Guido E.; Caruso, Paul A.; Curtin, Hugh D.; Small, Juan E.; Jyung, Robert W.; Troulis, Maria J.

    2008-01-01

    Cleidocranial dysplasia (CCD) is a multistructural polyostotic genetic disorder that results from mutation of the CBFA1 gene. Hearing loss is a frequent finding in CCD. We describe the CT craniofacial findings in CCD and provide a comprehensive discussion of the CT temporal bone findings in these patients. (orig.)

  2. Temporal bone dissection simulator for training pediatric otolaryngology surgeons

    Science.gov (United States)

    Tabrizi, Pooneh R.; Sang, Hongqiang; Talari, Hadi F.; Preciado, Diego; Monfaredi, Reza; Reilly, Brian; Arikatla, Sreekanth; Enquobahrie, Andinet; Cleary, Kevin

    2017-03-01

    Cochlear implantation is the standard of care for infants born with severe hearing loss. Current guidelines approve the surgical placement of implants as early as 12 months of age. Implantation at a younger age poses a greater surgical challenge since the underdeveloped mastoid tip, along with thin calvarial bone, creates less room for surgical navigation and can result in increased surgical risk. We have been developing a temporal bone dissection simulator based on actual clinical cases for training otolaryngology fellows in this delicate procedure. The simulator system is based on pre-procedure CT (Computed Tomography) images from pediatric infant cases (hospital. The simulator includes: (1) simulation engine to provide the virtual reality of the temporal bone surgery environment, (2) a newly developed haptic interface for holding the surgical drill, (3) an Oculus Rift to provide a microscopic-like view of the temporal bone surgery, and (4) user interface to interact with the simulator through the Oculus Rift and the haptic device. To evaluate the system, we have collected 10 representative CT data sets and segmented the key structures: cochlea, round window, facial nerve, and ossicles. The simulator will present these key structures to the user and warn the user if needed by continuously calculating the distances between the tip of surgical drill and the key structures.

  3. Cholesterol granuloma of temporal bone: CT and MR findings

    International Nuclear Information System (INIS)

    Ruiz Jauriguizuria, J.C.; Ferrero Collado, A.; Ereno Ealo, M.J.; Grande Icaran, D.

    1994-01-01

    Three cases of cholesterol granuloma of the left temporal bone are presented, two located in the petrous apex and the other at the otomastoid level. One of the patients had a history of mastoid surgery and the other surgery of the bone ridge. The three cases were confirmed histologically following surgical resection. The etiopathogenesis of the lesion is discussed, as are the clinical, histological and radiological features, with a broad description of the computed tomography and magnetic resonance findings. The differential diagnosis is also dealt with. (Author)

  4. Pneumatic control technology

    International Nuclear Information System (INIS)

    Tae, Seong Gil; Kim, Won Hoe; Nam, Dae Hyun

    1993-03-01

    This book contains property of pneumatic pressure drive, pneumatic pressure device like air cleaning, pressure control, lubricators, air pressure pipe, kinds and function of pneumatic pressure equipment like pneumatic cylinders, pneumatic motor, flow control valve, direction control valve, design of pneumatic control circuit, pneumatic system design, cause and measurement of pneumatic circuit failure, PLC and pneumatic control like introduction and system application and method of PLC programing.

  5. Intra-temporal facial nerve centerline segmentation for navigated temporal bone surgery

    Science.gov (United States)

    Voormolen, Eduard H. J.; van Stralen, Marijn; Woerdeman, Peter A.; Pluim, Josien P. W.; Noordmans, Herke J.; Regli, Luca; Berkelbach van der Sprenkel, Jan W.; Viergever, Max A.

    2011-03-01

    Approaches through the temporal bone require surgeons to drill away bone to expose a target skull base lesion while evading vital structures contained within it, such as the sigmoid sinus, jugular bulb, and facial nerve. We hypothesize that an augmented neuronavigation system that continuously calculates the distance to these structures and warns if the surgeon drills too close, will aid in making safe surgical approaches. Contemporary image guidance systems are lacking an automated method to segment the inhomogeneous and complexly curved facial nerve. Therefore, we developed a segmentation method to delineate the intra-temporal facial nerve centerline from clinically available temporal bone CT images semi-automatically. Our method requires the user to provide the start- and end-point of the facial nerve in a patient's CT scan, after which it iteratively matches an active appearance model based on the shape and texture of forty facial nerves. Its performance was evaluated on 20 patients by comparison to our gold standard: manually segmented facial nerve centerlines. Our segmentation method delineates facial nerve centerlines with a maximum error along its whole trajectory of 0.40+/-0.20 mm (mean+/-standard deviation). These results demonstrate that our model-based segmentation method can robustly segment facial nerve centerlines. Next, we can investigate whether integration of this automated facial nerve delineation with a distance calculating neuronavigation interface results in a system that can adequately warn surgeons during temporal bone drilling, and effectively diminishes risks of iatrogenic facial nerve palsy.

  6. Temporal bone trauma and complications: computed tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ana Maria Doffemond; Gaiotti, Juliana Oggioni; Couto, Caroline Laurita Batista; Gomes, Natalia Delage; Diniz, Renata Lopes Furletti Caldeira; Motta, Emilia Guerra Pinto Coelho, E-mail: anadoffemond@yahoo.com.br [Hospital Mater Dei, Belo Horizonte, MG (Brazil). Unit of Radiology and Imaging Diagnosis

    2013-03-15

    Most temporal bone fractures result from high-energy blunt head trauma, and are frequently related to other skull fractures or to polytrauma. Fractures and displacements of ossicular chain in the middle ear represent some of the main complications of temporal bone injury, and hence they will be more deeply approached in the present article. Other types of injuries include labyrinthine fractures, dural fistula, facial nerve paralysis and extension into the carotid canal. Computed tomography plays a fundamental role in the initial evaluation of polytrauma patients, as it can help to identify important structural injuries that may lead to severe complications such as sensorineural hearing loss, conductive hearing loss, dizziness and balance dysfunction, perilymphatic fistulas, facial nerve paralysis, vascular injury and others. (author)

  7. Temporal bone trauma and complications: computed tomography findings

    International Nuclear Information System (INIS)

    Costa, Ana Maria Doffemond; Gaiotti, Juliana Oggioni; Couto, Caroline Laurita Batista; Gomes, Natalia Delage; Diniz, Renata Lopes Furletti Caldeira; Motta, Emilia Guerra Pinto Coelho

    2013-01-01

    Most temporal bone fractures result from high-energy blunt head trauma, and are frequently related to other skull fractures or to polytrauma. Fractures and displacements of ossicular chain in the middle ear represent some of the main complications of temporal bone injury, and hence they will be more deeply approached in the present article. Other types of injuries include labyrinthine fractures, dural fistula, facial nerve paralysis and extension into the carotid canal. Computed tomography plays a fundamental role in the initial evaluation of polytrauma patients, as it can help to identify important structural injuries that may lead to severe complications such as sensorineural hearing loss, conductive hearing loss, dizziness and balance dysfunction, perilymphatic fistulas, facial nerve paralysis, vascular injury and others. (author)

  8. X-ray diagnosis in temporal bone anomalies

    International Nuclear Information System (INIS)

    Schratter, M.; Canigiani, G.; Swoboda, H.; Brunner, E.

    1988-01-01

    The X-ray findings in temporal bone anomalies are reviewed. Radiological procedure and examination technique are presented, as are symptoms of important anomalies. The methods available are plain film X-ray of temporal bone, multi-directional tomography, and high-resolution CT. Although some of the abnormalities are visible even in plain films, consistent use of conventional tomography or CT is necessary for correct diagnosis. This procedure is indicated not only when an abnormality is clinically obvious, but also in all cases of unexplained hearing loss without evidence of acquired disease. The advantage of CT over conventional tomography is that soft tissue anomalies, such as primary cholesteatoma or tumor simulating vascular abnormalities, can be demonstrated. In these cases CT is obligatory. (orig.) [de

  9. Three cases of temporal bone osteoradionecrosis after nasopharyngeal carcinoma treatment

    International Nuclear Information System (INIS)

    Yamatodani, Takashi; Mizuta, Kunihiro; Nakanishi, Hiroshi; Takizawa, Yoshinori; Hosokawa, Kumiko; Hosokawa, Seiji; Mineta, Hiroyuki

    2012-01-01

    Osteoradionecrosis is most commonly caused by radiation-induced injury. We report on 3 cases of temporal bone necrosis that occurred after chemoradiotherapy for nasopharyngeal carcinoma performed more than 10 years previously. Case 1 was a 42-year-old woman who had nasopharyngeal carcinoma in 1991. The patient underwent chemoradiotherapy (70 Gy total) in 1991, and gamma knife irradiation (20 Gy) in 1998 for local recurrence. The bone in the posterior wall of the left external auditory canal began to be exposed in 2003. Otorrhea from the left ear increased and we found a skin defect and ulcer formation in the postauricular region. We performed radical mastoidectomy and debridement on April, 2010. The area of the defect was covered and filled in with a pedicle musculoperiosteal flap. The intra-aural skin became dry in 6 months, however, she lost consciousness due to a temporal lobe abscess and underwent an emergency operation on April, 2011. After operation, the patient recovered with no neurological symptoms and infections up to the present date. Case 2 was a 58-year-old man who had nasopharyngeal carcinoma in 2001. The patient underwent chemoradiotherapy (66 Gy total) in 2001, and X knife irradiation (15 Gy) 3 months later due to the remaining tumor. The left posterior ear canal wall collapsed and the tympanic membrane retracted with pooling epithelial debris appearing in 2007. Left facial nerve palsy was seen in December 2010. We performed a mastoidectomy on January, 2011. Cholesteatoma and necrotic granuloma with fragile bone filled the mastoid cavity, and a facial canal bone defect was seen. Bone necrosis with cholesteatoma and inflammatory granuloma was revealed by the pathological examination. The facial palsy improved after the operation. Case 3 was a 59-year-old man who had left abducens palsy with nasopharyngeal carcinoma invading the clivus. The patient underwent chemoradiotherapy (60 Gy total) in 2001, and X knife irradiation (24 Gy) 4 months later for

  10. A metastatic glomus jugulare tumor. A temporal bone report

    International Nuclear Information System (INIS)

    El Fiky, F.M.; Paparella, M.M.

    1984-01-01

    The clinicopathologic findings in the temporal bone of a patient with a highly malignant metastasizing glomus jugulare tumor are reported. The patient exhibited all the symptoms of primary malignant tumors of the ear, including facial paralysis, otorrhea, pain, hearing loss, tinnitus, dizziness, and vertigo. He was treated with cobalt irradiation followed by radium implant in the ear canal for a residual tumor; then a left-sided radical mastoidectomy was performed

  11. Primary Ewing's Sarcoma of the temporal bone in an infant.

    Science.gov (United States)

    Goudarzipour, Kourosh; Shamsian, Shahin; Alavi, Samin; Nourbakhsh, Kazem; Aghakhani, Roxana; Eydian, Zahra; Arzanian, Mohammad Taghi

    2015-04-01

    Introduction : Ewing's sarcoma is the second most common primary malignant tumor of bone found in children after Osteosarcoma. It accounts for 4-9% of primary malignant bone tumors and it affects bones of the skull or face in only 1-4% of cases. Hence it rarely affects the head and neck. Subject and Method : In this case report, we describe a case of primary Ewing's sarcoma occurring in the temporal bone. The tumor was surgically excised, and the patient underwent chemotherapy for ten months. Results : Neither recurrence nor distant metastasis was noted in these 10 months after surgery but about 18 months after surgery our patient was expired. Conclusion : Although the prognosis of Ewing's sarcoma is generally poor because of early metastasis to the lungs and to other bones, a review of the article suggested that Ewing's sarcoma occurring in the skull can often be successfully managed by intensive therapy with radical excision and chemotherapy. This result was supported by the case reported here.

  12. Development of a robot for surgery of temporal bone

    International Nuclear Information System (INIS)

    Komune, Shizuo

    2011-01-01

    Described was development of a robot for drill-outing the mastoid process, the first essential step purposing such otologic surgery of temporal bone as tympanoplasty, cochlear implantation and tumor resection of auditory nerve, etc. A model of the bone prototyped by CT 3D data (Ono and Co., Ltd., Tokyo) was used for getting the trace of the drill-outing procedure by an expert, and information of the trace and bone position was registered by STAMP (surface template-assisted marker positioning), which was then integrated with a navigation system 3D slicer (a free, open source software) with use of data from position sensors of optical Polaris (NDI, Canada) and magnetic Aurora (NDI) on the drill tip. The sensors were also usable for recording the trace after the surgery as a log by MRI. The robot system was made to have thus 3 parts of drill-outing, operative navigation and control unit based on anatomical information. The drill-outing mechanic was made to have 6 degrees of freedom. Comparison of logs of the procedure conducted in the phantom bone by the robot and by an otologic operator gave agreement within error of 0.9 mm. More mechanical preciseness was thought desirable for reproducible operation. (author)

  13. Mixed reality temporal bone surgical dissector: mechanical design.

    Science.gov (United States)

    Hochman, Jordan Brent; Sepehri, Nariman; Rampersad, Vivek; Kraut, Jay; Khazraee, Milad; Pisa, Justyn; Unger, Bertram

    2014-08-08

    The Development of a Novel Mixed Reality (MR) Simulation. An evolving training environment emphasizes the importance of simulation. Current haptic temporal bone simulators have difficulty representing realistic contact forces and while 3D printed models convincingly represent vibrational properties of bone, they cannot reproduce soft tissue. This paper introduces a mixed reality model, where the effective elements of both simulations are combined; haptic rendering of soft tissue directly interacts with a printed bone model. This paper addresses one aspect in a series of challenges, specifically the mechanical merger of a haptic device with an otic drill. This further necessitates gravity cancelation of the work assembly gripper mechanism. In this system, the haptic end-effector is replaced by a high-speed drill and the virtual contact forces need to be repositioned to the drill tip from the mid wand. Previous publications detail generation of both the requisite printed and haptic simulations. Custom software was developed to reposition the haptic interaction point to the drill tip. A custom fitting, to hold the otic drill, was developed and its weight was offset using the haptic device. The robustness of the system to disturbances and its stable performance during drilling were tested. The experiments were performed on a mixed reality model consisting of two drillable rapid-prototyped layers separated by a free-space. Within the free-space, a linear virtual force model is applied to simulate drill contact with soft tissue. Testing illustrated the effectiveness of gravity cancellation. Additionally, the system exhibited excellent performance given random inputs and during the drill's passage between real and virtual components of the model. No issues with registration at model boundaries were encountered. These tests provide a proof of concept for the initial stages in the development of a novel mixed-reality temporal bone simulator.

  14. Repair of Temporal Bone Encephalocele following Canal Wall Down Mastoidectomy

    Directory of Open Access Journals (Sweden)

    Sarantis Blioskas

    2014-01-01

    Full Text Available We report a rare case of a temporal bone encephalocele after a canal wall down mastoidectomy performed to treat chronic otitis media with cholesteatoma. The patient was treated successfully via an intracranial approach. An enhanced layer-by-layer repair of the encephalocele and skull base deficit was achieved from intradurally to extradurally, using temporalis fascia, nasal septum cartilage, and artificial dural graft. After a 22-month follow-up period the patient remains symptom free and no recurrence is noted.

  15. Practical pneumatics

    CERN Document Server

    Stacey, Chris

    2012-01-01

    Pneumatic power is ideal for the ever increasing range of 'light' applications in which a cheap, clean, adaptable source of power is needed. Used in conjunction with microprocessor control it forms the basis of manufacturing automation from basic conveying and handling lines to complex robotic assembly systems. Training courses and books aimed at the technician have not kept pace with these developments. This book is written to cover the British Fluid Power Association Pneumatics Certificate, which is also awarded as part of CGLI scheme 2340, and is in the process of NVQ accreditation at level

  16. Transmastoid approach to temporal bone cerebrospinal fluid leaks.

    Science.gov (United States)

    Oliaei, Sepehr; Mahboubi, Hossein; Djalilian, Hamid R

    2012-01-01

    The aim of the study was to evaluate various presentations and treatment options for spontaneous cerebrospinal fluid (CSF) leakage originating in the temporal bone. Clinical data and imaging results for 18 ears (15 patients) presenting with spontaneous CSF leakage originating in the temporal bone were reviewed. Average follow-up period was 13.5 months. The main outcome measure was presence of persistent CSF leak postoperatively. A standard postauricular mastoidectomy was performed. Fifteen patients diagnosed with spontaneous CSF leakage over an 8-year period including 3 treated for bilateral disease were included in the study. The age ranged between 33 and 83 years. Presenting symptoms included serous otitis media (44%), persistent otorrhea after tympanostomy tube placement (28%), and meningitis (28%). Preoperative diagnosis was made using imaging studies and was substantiated by observation of CSF leakage and dural herniation intraoperatively. Treatment was eustachian tube plugging (5%), mastoidectomy with fat obliteration (61%), middle fossa approach with extradural (17%), intradural repair (5%), or combined middle fossa and transmastoid (TM) approach (11%). Successful treatment was obtained in 17 of the 18 cases. The last 9 patients in the series underwent TM approach alone for repair with no treatment failures. Repair of defects in tegmen mastoideum and posterior fossa can be successfully achieved on an outpatient basis without regard to size and multitude of defects via TM approach. This approach obviates the need for a craniotomy or lumbar drain. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Osteoradionecrosis of the temporal bone with cancer of the middle ear. A case report

    International Nuclear Information System (INIS)

    Ishida, Katsunori; Sakai, Makoto; Shinkawa, Atsushi

    1999-01-01

    Osteoradionecrosis of the temporal bone may occur as a result of radiation therapy for head and neck carcinomas or brain tumors. A 64-year-old female received radiation therapy for squamous cell carcinoma of the middle ear 20 years ago, and then she developed osteoradionecrosis of the temporal bone. The patient underwent extensive debridement with removal of sequestrations in the temporal bone and adjacent areas, and abscess drainage. Her postoperative course was satisfactory and there was no progression of the disease. (author)

  18. A case of a temporal bone meningioma presenting as a serous otitis media

    International Nuclear Information System (INIS)

    Nicolay, Simon; De Foer, Bert; Bernaerts, Anja; Van Dinther, Joost; Parizel, Paul M

    2014-01-01

    We report the imaging features of a case of a temporal bone meningioma extending into the middle ear cavity and clinically presenting as a serous otitis media. Temporal bone meningioma extending in the mastoid or the middle ear cavity, however, is very rare. In case of unexplained or therapy-resistant serous otitis media and a nasopharyngeal tumor being ruled out, a temporal bone computed tomography (CT) should be performed. If CT findings are suggestive of a temporal bone meningioma, a magnetic resonance imaging (MRI) examination with gadolinium will confirm diagnosis and show the exact extension of the lesion

  19. Multi-material 3D Models for Temporal Bone Surgical Simulation.

    Science.gov (United States)

    Rose, Austin S; Kimbell, Julia S; Webster, Caroline E; Harrysson, Ola L A; Formeister, Eric J; Buchman, Craig A

    2015-07-01

    A simulated, multicolor, multi-material temporal bone model can be created using 3-dimensional (3D) printing that will prove both safe and beneficial in training for actual temporal bone surgical cases. As the process of additive manufacturing, or 3D printing, has become more practical and affordable, a number of applications for the technology in the field of Otolaryngology-Head and Neck Surgery have been considered. One area of promise is temporal bone surgical simulation. Three-dimensional representations of human temporal bones were created from temporal bone computed tomography (CT) scans using biomedical image processing software. Multi-material models were then printed and dissected in a temporal bone laboratory by attending and resident otolaryngologists. A 5-point Likert scale was used to grade the models for their anatomical accuracy and suitability as a simulation of cadaveric and operative temporal bone drilling. The models produced for this study demonstrate significant anatomic detail and a likeness to human cadaver specimens for drilling and dissection. Simulated temporal bones created by this process have potential benefit in surgical training, preoperative simulation for challenging otologic cases, and the standardized testing of temporal bone surgical skills. © The Author(s) 2015.

  20. Evaluation on temporal bone CT findings of cholesteatoma

    International Nuclear Information System (INIS)

    Lee, Kun Won; Lee, Nam Joon; Kang, Eun Young; Chung, Kyoo Byung; Suh, Won Hyuck

    1989-01-01

    Cholesteatomas are thought to result from ingrowth of keratinizing squamous epithelium from external ear to middle ear. The cholesteatomas are usually diagnosed by clinical symptoms and signs, otoscopy, and plain radiograms. But various view points are emphasized radiologically before operation, leading to examine by computed tomography (CT), especially in complicated cases. We retrospectively reviewed the CT findings of cholesteatomas in 25 surgically proven cases during the period from May, 1983 to Aug, 1988. The results were as follows: 1. Most cholesteatomas showed soft tissue mass and bony erosion of ossicles (88%), attic wall and mastoid antrum (84%) on temporal bone CT scan. 2. The CT members of cholesteatomas ranged from 25 to 50 HU (avg. 33 HU). 3. Involved sites were attic (16%), antrum (28%), and both attic and antrum (56%). Other sites were middle ear cavity and external auditory canal. 4. Extra-tympanomastoid extension of cholesteatoma was intracranial abscess (8%), exposure of dural sinus (8%), and extension along with neck (4%)

  1. Three-dimensional measurement of temporal bone by using personal computer

    International Nuclear Information System (INIS)

    Kimura, Hiroki; Murata, Kiyotaka; Isono, Michio; Azuma, Hiroji; Itou, Akihiko

    1996-01-01

    Measurement of anatomical indices in human temporal bone has been reported only sporadically using high resolution CT. We developed a method for measuring such indices by computer assisted processing of images obtained by high resolusion CT. Intensive measurement of distances between all anatomical points in the entire temporal bone structure became possible with this method. (author)

  2. Anatomic and Quantitative Temporal Bone CT for Preoperative Assessment of Branchio-Oto-Renal Syndrome.

    Science.gov (United States)

    Ginat, D T; Ferro, L; Gluth, M B

    2016-12-01

    We describe the temporal bone computed tomography (CT) findings of an unusual case of branchio-oto-renal syndrome with ectopic ossicles that are partially located in the middle cranial fossa. We also describe quantitative temporal bone CT assessment pertaining to cochlear implantation in the setting of anomalous cochlear anatomy associated with this syndrome.

  3. Histology of sheep temporal bone A histologia do osso temporal do ovino

    Directory of Open Access Journals (Sweden)

    Hormy Biavatti Soares

    2011-06-01

    Full Text Available Previous studies suggest that there is an excellent correlation between the morphology and dimensions of ear structures in sheep and human beings. AIM: To analyze and describe the histology of structures inside the temporal bone in sheep. MATERIAL AND METHODS: A total of 307 slides obtained from vertical and horizontal sections of the temporal bone of eight sheep were analyzed. Structures were classified as similar or not similar to human structures, based on cellularity and histological architecture parameters. STUDY DESIGN: Experimental. RESULTS: The study revealed similarities between sheep and humans in terms of type of epithelium, bone component, spaces in the auditory meatus, in addition to a marked histological resemblance of cellularity and that of the structures surrounding the ear. The main differences observed were the presence of an anatomic bulla, the absence of aeration in the mastoid and the inferior opening of the hypotympanum into the bulla in sheep. CONCLUSION: Based on these observations, it is possible to conclude that sheep represent an adequate option for training and research in otologic surgery.Resultados prévios apontam para uma ótima correlação entre a morfologia e as dimensões das estruturas anatômicas de ovelhas e seres humanos. OBJETIVO: Analisar e descrever a histologia das estruturas que compõem o osso temporal do ovino. MATERIAL E MÉTODO: Um total de 307 lâminas obtidas a partir de secções verticais e horizontais do osso temporal de oito ovelhas foi analisado. As estruturas foram caracterizadas como semelhantes ou não semelhantes às do ser humano, com base na celularidade e na arquitetura histológica das estruturas. DESENHO CIENTÍFICO: Experimental. RESULTADOS: Constatou-se semelhança quanto ao tipo de epitélio, componente ósseo, espaços da fenda auditiva e arquitetura, além da semelhança, em nível histológico, tanto dos componentes celulares como das estruturas contíguas ao ouvido. As

  4. Primary pericranial Ewing's sarcoma on the temporal bone: A case report.

    Science.gov (United States)

    Kawano, Hiroto; Nitta, Naoki; Ishida, Mitsuaki; Fukami, Tadateru; Nozaki, Kazuhiko

    2016-01-01

    Primary Ewing's sarcoma originating in the pericranium is an extremely rare disease entity. A 9-year-old female patient was admitted to our department due to a left temporal subcutaneous mass. The mass was localized under the left temporal muscle and attached to the surface of the temporal bone. Head computed tomography revealed a mass with bony spicule formation on the temporal bone, however, it did not show bone destruction or intracranial invasion. F-18 fluorodeoxyglucose positron emission tomography showed no lesions other than the mass on the temporal bone. Magnetic resonance imaging showed that the mass was located between the temporal bone and the pericranium. The mass was completely resected with the underlying temporal bone and the overlying deep layer of temporal muscle, and was diagnosed as primary Ewing's sarcoma. Because the tumor was located in the subpericranium, we created a new classification, "pericranial Ewing's sarcoma," and diagnosed the present tumor as pericranial Ewing's sarcoma. We herein present an extremely rare case of primary pericranial Ewing's sarcoma that developed on the temporal bone.

  5. Vertebral Pneumaticity in the Ornithomimosaur Archaeornithomimus (Dinosauria: Theropoda Revealed by Computed Tomography Imaging and Reappraisal of Axial Pneumaticity in Ornithomimosauria.

    Directory of Open Access Journals (Sweden)

    Akinobu Watanabe

    Full Text Available Among extant vertebrates, pneumatization of postcranial bones is unique to birds, with few known exceptions in other groups. Through reduction in bone mass, this feature is thought to benefit flight capacity in modern birds, but its prevalence in non-avian dinosaurs of variable sizes has generated competing hypotheses on the initial adaptive significance of postcranial pneumaticity. To better understand the evolutionary history of postcranial pneumaticity, studies have surveyed its distribution among non-avian dinosaurs. Nevertheless, the degree of pneumaticity in the basal coelurosaurian group Ornithomimosauria remains poorly known, despite their potential to greatly enhance our understanding of the early evolution of pneumatic bones along the lineage leading to birds. Historically, the identification of postcranial pneumaticity in non-avian dinosaurs has been based on examination of external morphology, and few studies thus far have focused on the internal architecture of pneumatic structures inside the bones. Here, we describe the vertebral pneumaticity of the ornithomimosaur Archaeornithomimus with the aid of X-ray computed tomography (CT imaging. Complementary examination of external and internal osteology reveals (1 highly pneumatized cervical vertebrae with an elaborate configuration of interconnected chambers within the neural arch and the centrum; (2 anterior dorsal vertebrae with pneumatic chambers inside the neural arch; (3 apneumatic sacral vertebrae; and (4 a subset of proximal caudal vertebrae with limited pneumatic invasion into the neural arch. Comparisons with other theropod dinosaurs suggest that ornithomimosaurs primitively exhibited a plesiomorphic theropod condition for axial pneumaticity that was extended among later taxa, such as Archaeornithomimus and large bodied Deinocheirus. This finding corroborates the notion that evolutionary increases in vertebral pneumaticity occurred in parallel among independent lineages of bird

  6. Endolymphatic Sac Tumors and Papillary Adenocarcinoma of the Temporal Bone:Role of MRI and CT

    OpenAIRE

    Mahmood F. Mafee; Hemant Shah

    2003-01-01

    Adenomatous Tumors of the temporal bone are rare. Benign adenomatous neoplasms (adenoma) of the middle ear are a distinctive benign tumor based on histological and clinical observations. Papillary adenocarcinomas of the temporal bone are invasive tumors. Although, the exact site of origin of these neoplasms is not identified, owing to the local bone destruction (usually centered at posterior petromastoid plate), the general consensus favors the endolymphatic sac as being the origin of these t...

  7. Primary Ewing's Sarcoma of the Temporal Bone: A Rare Case Report and Literature Review.

    Science.gov (United States)

    Gupta, Divya; Gulati, Achal; Purnima

    2017-09-01

    Ewing's sarcoma is a malignant, round cell tumor arising from the bones and primarily affecting children and adolescent, accounting for 3 % of all childhood malignancies. Although the long bones and the trunk are typically affected, rare cases of it involving isolated bones throughout the body have been reported. Involvement of the skull bones is rare, constituting 1-6 % of the total Ewing's sarcoma cases but those affecting the cranial bones are rarer still, constituting only 1 %. We describe an 8 months old infant having Ewing sarcoma, of the petrous and mastoid parts of temporal bone along with the occipital bone, whose clinical presentation mimicked mastoiditis with facial nerve palsy. We discuss the clinical and therapeutic course of an extensive primary Ewing sarcoma of the temporal bone, which was treated without performing surgery and review this entity's literature in detail.

  8. Assessment of skills using a virtual reality temporal bone surgery simulator.

    Science.gov (United States)

    Linke, R; Leichtle, A; Sheikh, F; Schmidt, C; Frenzel, H; Graefe, H; Wollenberg, B; Meyer, J E

    2013-08-01

    Surgery on the temporal bone is technically challenging due to its complex anatomy. Precise anatomical dissection of the human temporal bone is essential and is fundamental for middle ear surgery. We assessed the possible application of a virtual reality temporal bone surgery simulator to the education of ear surgeons. Seventeen ENT physicians with different levels of surgical training and 20 medical students performed an antrotomy with a computer-based virtual temporal bone surgery simulator. The ease, accuracy and timing of the simulated temporal bone surgery were assessed using the automatic assessment software provided by the simulator device and additionally with a modified Final Product Analysis Scale. Trained ENT surgeons, physicians without temporal bone surgical training and medical students were all able to perform the antrotomy. However, the highly trained ENT surgeons were able to complete the surgery in approximately half the time, with better handling and accuracy as assessed by the significant reduction in injury to important middle ear structures. Trained ENT surgeons achieved significantly higher scores using both dissection analysis methods. Surprisingly, there were no significant differences in the results between medical students and physicians without experience in ear surgery. The virtual temporal bone training system can stratify users of known levels of experience. This system can be used not only to improve the surgical skills of trained ENT surgeons for more successful and injury-free surgeries, but also to train inexperienced physicians/medical students in developing their surgical skills for the ear.

  9. Facial nerve paralysis associated with temporal bone masses.

    Science.gov (United States)

    Nishijima, Hironobu; Kondo, Kenji; Kagoya, Ryoji; Iwamura, Hitoshi; Yasuhara, Kazuo; Yamasoba, Tatsuya

    2017-10-01

    To investigate the clinical and electrophysiological features of facial nerve paralysis (FNP) due to benign temporal bone masses (TBMs) and elucidate its differences as compared with Bell's palsy. FNP assessed by the House-Brackmann (HB) grading system and by electroneurography (ENoG) were compared retrospectively. We reviewed 914 patient records and identified 31 patients with FNP due to benign TBMs. Moderate FNP (HB Grades II-IV) was dominant for facial nerve schwannoma (FNS) (n=15), whereas severe FNP (Grades V and VI) was dominant for cholesteatomas (n=8) and hemangiomas (n=3). The average ENoG value was 19.8% for FNS, 15.6% for cholesteatoma, and 0% for hemangioma. Analysis of the correlation between HB grade and ENoG value for FNP due to TBMs and Bell's palsy revealed that given the same ENoG value, the corresponding HB grade was better for FNS, followed by cholesteatoma, and worst in Bell's palsy. Facial nerve damage caused by benign TBMs could depend on the underlying pathology. Facial movement and ENoG values did not correlate when comparing TBMs and Bell's palsy. When the HB grade is found to be unexpectedly better than the ENoG value, TBMs should be included in the differential diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Differential Intracochlear Sound Pressure Measurements in Normal Human Temporal Bones

    Science.gov (United States)

    Nakajima, Hideko Heidi; Dong, Wei; Olson, Elizabeth S.; Merchant, Saumil N.; Ravicz, Michael E.; Rosowski, John J.

    2009-02-01

    We present the first simultaneous sound pressure measurements in scala vestibuli and scala tympani of the cochlea in human cadaveric temporal bones. Micro-scale fiberoptic pressure sensors enabled the study of differential sound pressure at the cochlear base. This differential pressure is the input to the cochlear partition, driving cochlear waves and auditory transduction. Results showed that: pressure of scala vestibuli was much greater than scala tympani except at low and high frequencies where scala tympani pressure affects the input to the cochlea; the differential pressure proved to be an excellent measure of normal ossicular transduction of sound (shown to decrease 30-50 dB with ossicular disarticulation, whereas the individual scala pressures were significantly affected by non-ossicular conduction of sound at high frequencies); the middle-ear gain and differential pressure were generally bandpass in frequency dependence; and the middle-ear delay in the human was over twice that of the gerbil. Concurrent stapes velocity measurements allowed determination of the differential impedance across the partition and round-window impedance. The differential impedance was generally resistive, while the round-window impedance was consistent with a compliance in conjunction with distributed inertia and damping. Our techniques can be used to study inner-ear conductive pathologies (e.g., semicircular dehiscence), as well as non-ossicular cochlear stimulation (e.g., round-window stimulation) - situations that cannot be completely quantified by measurements of stapes velocity or scala-vestibuli pressure by themselves.

  11. Developing effective automated feedback in temporal bone surgery simulation.

    Science.gov (United States)

    Wijewickrema, Sudanthi; Piromchai, Patorn; Zhou, Yun; Ioannou, Ioanna; Bailey, James; Kennedy, Gregor; O'Leary, Stephen

    2015-06-01

    We aim to test the effectiveness, accuracy, and usefulness of an automated feedback system in facilitating skill acquisition in virtual reality surgery. We evaluate the performance of the feedback system through a randomized controlled trial of 24 students allocated to feedback and nonfeedback groups. The feedback system was based on the Melbourne University temporal bone surgery simulator. The study was conducted at the simulation laboratory of the Royal Victorian Eye and Ear Hospital, Melbourne. The study participants were medical students from the University of Melbourne, who were asked to perform virtual cortical mastoidectomy on the simulator. The extent to which the drilling behavior of the feedback and nonfeedback groups differed was used to evaluate the effectiveness of the system. Its accuracy was determined through a postexperiment observational assessment of recordings made during the experiment by an expert surgeon. Its usability was evaluated using students' self-reports of their impressions of the system. A Friedman's test showed that there was a significant improvement in the drilling performance of the feedback group, χ(2)(1) = 14.450, P feedback (when trainee behavior was detected) 88.6% of the time and appropriate feedback (accurate advice) 84.2% of the time. Participants' opinions about the usefulness of the system were highly positive. The automated feedback system was observed to be effective in improving surgical technique, and the provided feedback was found to be accurate and useful. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  12. Computed tomography of the temporal bone and orbit

    International Nuclear Information System (INIS)

    Zonneveld, F.W.

    1987-01-01

    The basis for this dissertation is the combination of the best set of high-resolution CT scanning parameters, on the one hand, and the technique of scanning perpendicular to the tissue interface, or parallel to an elongated anatomical structure (direct multiplanar CT technique) on the other. Although this technique yields better visualization of a number of anatomical details, the problem remains that the radiologist is as yet unfamiliar with these alternative cross-sectional planes. For this reason, a technique for cryosectioning fresh frozen specimens was selected and improved to create cross-sectional images that can be correlated with the direct multiplanar CT scans. The selection of special scan planes, the positioning, preparation and examination of the patient, and the CT and correlative anatomy are discussed separately for the temporal bone and the orbit. A few clinical applications are discussed. In the orbit, the value of high-resolution CT is demonstrated in the establishment of the relationship between space-occupying lesions and the optic nerve, and in the management of fractures of the orbital floor. 548 refs.; 253 figs.; 24 tabs

  13. Utility of 3D printed temporal bones in pre-surgical planning for complex BoneBridge cases.

    Science.gov (United States)

    Mukherjee, Payal; Cheng, Kai; Flanagan, Sean; Greenberg, Simon

    2017-08-01

    With the advent of single-sided hearing loss increasingly being treated with cochlear implantation, bone conduction implants are reserved for cases of conductive and mixed hearing loss with greater complexity. The BoneBridge (BB, MED-EL, Innsbruck, Austria) is an active fully implantable device with no attenuation of sound energy through soft tissue. However, the floating mass transducer (FMT) part of the device is very bulky, which limits insertion in complicated ears. In this study, 3D printed temporal bones of patients were used to study its utility in preoperative planning on complicated cases. Computed tomography (CT) scans of 16 ears were used to 3D print their temporal bones. Three otologists graded the use of routine preoperative planning provided by MED-EL and that of operating on the 3D printed bone of the patient. Data were collated to assess the advantage and disadvantage of the technology. There was a statistically significant benefit in using 3D printed temporal bones to plan surgery for difficult cases of BoneBridge surgery compared to the current standard. Surgeons preferred to have the printed bones in theatre to plan their drill sites and make the transition of the planning to the patient's operation more precise. 3D printing is an innovative use of technology in the use of preoperative planning for complex ear surgery. Surgical planning can be done on the patient's own anatomy which may help to decrease operating time, reduce cost, increase surgical precision and thus reduce complications.

  14. Pre-operative simulation of pediatric mastoid surgery with 3D-printed temporal bone models.

    Science.gov (United States)

    Rose, Austin S; Webster, Caroline E; Harrysson, Ola L A; Formeister, Eric J; Rawal, Rounak B; Iseli, Claire E

    2015-05-01

    As the process of additive manufacturing, or three-dimensional (3D) printing, has become more practical and affordable, a number of applications for the technology in the field of pediatric otolaryngology have been considered. One area of promise is temporal bone surgical simulation. Having previously developed a model for temporal bone surgical training using 3D printing, we sought to produce a patient-specific model for pre-operative simulation in pediatric otologic surgery. Our hypothesis was that the creation and pre-operative dissection of such a model was possible, and would demonstrate potential benefits in cases of abnormal temporal bone anatomy. In the case presented, an 11-year-old boy underwent a planned canal-wall-down (CWD) tympano-mastoidectomy for recurrent cholesteatoma preceded by a pre-operative surgical simulation using 3D-printed models of the temporal bone. The models were based on the child's pre-operative clinical CT scan and printed using multiple materials to simulate both bone and soft tissue structures. To help confirm the models as accurate representations of the child's anatomy, distances between various anatomic landmarks were measured and compared to the temporal bone CT scan and the 3D model. The simulation allowed the surgical team to appreciate the child's unusual temporal bone anatomy as well as any challenges that might arise in the safety of the temporal bone laboratory, prior to actual surgery in the operating room (OR). There was minimal variability, in terms of absolute distance (mm) and relative distance (%), in measurements between anatomic landmarks obtained from the patient intra-operatively, the pre-operative CT scan and the 3D-printed models. Accurate 3D temporal bone models can be rapidly produced based on clinical CT scans for pre-operative simulation of specific challenging otologic cases in children, potentially reducing medical errors and improving patient safety. Copyright © 2015 Elsevier Ireland Ltd. All rights

  15. Evaluation of CT-scanning of the temporal bone in the diagnosis of ear diseases

    International Nuclear Information System (INIS)

    Murata, Kiyotaka; Isono, Michio; Nishimae, Tadahide; Tamaki, Katsuhiko; Hosoi, Hiroshi; Ohta, Fumihiko

    1983-01-01

    CT-scanning of 96 temporal bones was carried out to reveal the extension of cholesteatoma, periossicular drainage, fracture lines, enlarged internal acoustic meatus and anomalies of labyrinthine capsules and ossicles. The clinical aspects of CT-scanning of the temporal bone (CTTB) were as follows: 1) Inner ear anomalies were observed in 17 temporal bones of unilateral deafness, high tone loss from unknown origin and fluctuant hearing loss. CTTB may explain the pathology of deafness from unknown origin. 2) Inner ear anomalies may be classified into more detailed groups than before. 3) The extension of cholesteatoma, localization and size of labyrinthine fistula can be estimated prior to surgery. 4) Cholesteatoma in a mastoidectomy cavity may be detected. 5) The malleus and incus may be visualized, although the stapes can hardly be found. 6) Fracture lines of a temporal bone, destruction of the internal acoustic meatus may be clearly detected. (author)

  16. Locating the scala media in the fixed human temporal bone for therapeutic access: a preliminary study.

    Science.gov (United States)

    Pau, H; Fagan, P; Oleskevich, S

    2006-11-01

    To investigate the location of the scala media in relation to the round window niche in human temporal bones. Ten human temporal bones were investigated by radical mastoidectomy and promontory drill-out. Temporal bone laboratory. The distance from the scala media to the anterior edge of the round window niche, measured by Fisch's stapedectomy measuring cylinders. The scala media was identified at the transection point of a vertical line 1.6 to 2.2 mm (mean=1.8 mm; standard deviation=0.2) anterior to the anterior edge of the round window niche and a horizontal line 0.2 mm inferior to the lower border of the oval window. This report demonstrates the point of entry into the scala media via the promontory in fixed temporal bone models, which may provide a site of entry for stem cells and gene therapy insertion.

  17. High-resolution computed tomography of the temporal bone. Part 2.: pathology

    International Nuclear Information System (INIS)

    Grzegorzewski, M.; Boron, Z.; Burzynska-Makuch, M.

    1995-01-01

    Selected cases of the temporal bone pathology on high resolution CT were demonstrated. Transverse and coronal sections of the cases were selected from 68 patients with various otological diseases. (author)

  18. la dysplasie fibreuse du rocher fibrous dysplasia of the temporal bone

    African Journals Online (AJOL)

    view of the disease and its manifestations in the temporal bone. Ann. OtolRhinolLaryngol 1982;92(Suppl.): 1–52. 5- Papadakis CE, Skoulakis CE, Propakapis EP, et al. Fibrous dyspla- sia of the temporal bone: report of a case and review of its characteris- tics. Ear Nose Throat J, 2000;79:52–57. 6- Yang H, Chen S, Zheng Y, ...

  19. Inflammatory Pseudotumor of the Temporal Bone: Three Cases and a Review of the Literature

    Directory of Open Access Journals (Sweden)

    Huiqin Tian

    2013-01-01

    Full Text Available Inflammatory pseudotumor (IP is a clinically aggressive but histologically benign condition of unknown cause. Its appearance in the temporal bone is uncommon. We present clinical, radiological, and histopathologic findings of three cases originating in the temporal bone. In the first case, a simultaneous IP of the temporal bone and parotid gland was found with histopathologic confirmation. In the second case, an enlarged cervical node, which was also believed to be related to IP, was observed accompanied with the temporal lesion. While the third case presented with chronic suppurative otitis media. Two of them were treated by surgery alone with complete resolve of the diseases. Another one underwent tympanomastoidectomy in combination with oral steroids, radiation, and chemotherapy, but the IP still recurred. A comprehensive review of the literature on clinical features of the temporal pseudotumor was conducted.

  20. A review of simulation platforms in surgery of the temporal bone.

    Science.gov (United States)

    Bhutta, M F

    2016-10-01

    Surgery of the temporal bone is a high-risk activity in an anatomically complex area. Simulation enables rehearsal of such surgery. The traditional simulation platform is the cadaveric temporal bone, but in recent years other simulation platforms have been created, including plastic and virtual reality platforms. To undertake a review of simulation platforms for temporal bone surgery, specifically assessing their educational value in terms of validity and in enabling transition to surgery. Systematic qualitative review. Search of the Pubmed, CINAHL, BEI and ERIC databases. Assessment of reported outcomes in terms of educational value. A total of 49 articles were included, covering cadaveric, animal, plastic and virtual simulation platforms. Cadaveric simulation is highly rated as an educational tool, but there may be a ceiling effect on educational outcomes after drilling 8-10 temporal bones. Animal models show significant anatomical variation from man. Plastic temporal bone models offer much potential, but at present lack sufficient anatomical or haptic validity. Similarly, virtual reality platforms lack sufficient anatomical or haptic validity, but with technological improvements they are advancing rapidly. At present, cadaveric simulation remains the best platform for training in temporal bone surgery. Technological advances enabling improved materials or modelling mean that in the future plastic or virtual platforms may become comparable to cadaveric platforms, and also offer additional functionality including patient-specific simulation from CT data. © 2015 John Wiley & Sons Ltd.

  1. Human multipotent mesenchymal stromal cells in the treatment of postoperative temporal bone defect: an animal model

    Czech Academy of Sciences Publication Activity Database

    Školoudík, L.; Chrobok, V.; Kalfert, D.; Kočí, Zuzana; Syková, Eva; Chumak, Tetyana; Popelář, Jiří; Syka, Josef; Laco, J.; Dědková, J.; Dayanithi, Govindan; Filip, S.

    2016-01-01

    Roč. 25, č. 7 (2016), s. 1405-1414 ISSN 0963-6897 R&D Projects: GA MŠk(CZ) LO1309 Institutional support: RVO:68378041 Keywords : Human bone marrow * Human mesenchymal stromal cells (hMSCs) * Middle ear surgery * Temporal bone Subject RIV: FP - Other Medical Disciplines Impact factor: 3.006, year: 2016

  2. Content Validity of Temporal Bone Models Printed Via Inexpensive Methods and Materials.

    Science.gov (United States)

    Bone, T Michael; Mowry, Sarah E

    2016-09-01

    Computed tomographic (CT) scans of the 3-D printed temporal bone models will be within 15% accuracy of the CT scans of the cadaveric temporal bones. Previous studies have evaluated the face validity of 3-D-printed temporal bone models designed to train otolaryngology residents. The purpose of the study was to determine the content validity of temporal bone models printed using inexpensive printers and materials. Four cadaveric temporal bones were randomly selected and clinical temporal bone CT scans were obtained. Models were generated using previously described methods in acrylonitrile butadiene styrene (ABS) plastic using the Makerbot Replicator 2× and Hyrel printers. Models were radiographically scanned using the same protocol as the cadaveric bones. Four images from each cadaveric CT series and four corresponding images from the model CT series were selected, and voxel values were normalized to black or white. Scan slices were compared using PixelDiff software. Gross anatomic structures were evaluated in the model scans by four board certified otolaryngologists on a 4-point scale. Mean pixel difference between the cadaver and model scans was 14.25 ± 2.30% at the four selected CT slices. Mean cortical bone width difference and mean external auditory canal width difference were 0.58 ± 0.66 mm and 0.55 ± 0.46 mm, respectively. Expert raters felt the mastoid air cells were well represented (2.5 ± 0.5), while middle ear and otic capsule structures were not accurately rendered (all averaged bones for training residents in cortical mastoidectomies, but less effective for middle ear procedures.

  3. Correlations of External Landmarks With Internal Structures of the Temporal Bone.

    Science.gov (United States)

    Piromchai, Patorn; Wijewickrema, Sudanthi; Smeds, Henrik; Kennedy, Gregor; O'Leary, Stephen

    2015-09-01

    The internal anatomy of a temporal bone could be inferred from external landmarks. Mastoid surgery is an important skill that ENT surgeons need to acquire. Surgeons commonly use CT scans as a guide to understanding anatomical variations before surgery. Conversely, in cases where CT scans are not available, or in the temporal bone laboratory where residents are usually not provided with CT scans, it would be beneficial if the internal anatomy of a temporal bone could be inferred from external landmarks. We explored correlations between internal anatomical variations and metrics established to quantify the position of external landmarks that are commonly exposed in the operating room, or the temporal bone laboratory, before commencement of drilling. Mathematical models were developed to predict internal anatomy based on external structures. From an operating room view, the distances between the following external landmarks were observed to have statistically significant correlations with the internal anatomy of a temporal bone: temporal line, external auditory canal, mastoid tip, occipitomastoid suture, and Henle's spine. These structures can be used to infer a low lying dura mater (p = 0.002), an anteriorly located sigmoid sinus (p = 0.006), and a more lateral course of the facial nerve (p external landmarks. The distances between these two landmarks and the operating view external structures were able to further infer the laterality of the facial nerve (p internal structures with a high level of accuracy: the distance from the sigmoid sinus to the posterior external auditory canal (p external landmarks found on the temporal bone. These relationships could be used as a guideline to predict challenges during drilling and choosing appropriate temporal bones for dissection.

  4. Anatomia do osso temporal de ovelhas sob aspectos didáticos Lambs' temporal bone anatomy under didactic aspects

    Directory of Open Access Journals (Sweden)

    André Gurr

    2011-02-01

    Full Text Available É difícil encontrar ossos temporais humanos para o ensino de cirurgia otológica. Ossos temporais de ovelhas podem representar uma possível alternativa. MATERIAIS E MÉTODOS: Os ossos temporais de ovelhas foram dissecados em um programa convencional de dissecação de osso temporal no laboratório. Incluímos mastoidectomia, abordagens endaurais, mas também analisamos a aparência externa, o meato acústico externo e o hipotímpano. Algumas etapas são diferentes das preparações de ossos humanos. Os resultados morfométricos foram comparados à anatomia conhecida de humanos para verificar se o osso temporal de ovelhas seria utilizável para o ensino de cirurgia otológica. RESULTADOS: O osso temporal de ovelhas parece menor do que o humano. Encontramos uma área bolhosa se estendendo ao hipotímpano abaixo do meato acústico externo. A membrana timpânica é muito semelhante à humana. O meato acústico externo é menor e mais curto. A cadeia ossicular exibe analogias para com a humana. DISCUSSÃO: Esse estudo mostra que especificamente o ouvido médio, a membrana timpânica e o conduto auditivo externo são morfologicamente semelhantes às suas contrapartidas encontradas nos ossos temporais humanos. A ovelha parece ser um modelo viável para o ensino da anatomia do ouvido. A menor escala de algumas estruturas, especialmente dos componentes externos do osso temporal representa uma desvantagem. CONCLUSÕES: A ovelha parece representar uma alternativa viável no ensino de cirurgia otológica.Human temporal bones in teaching ear surgery are rare. The lamb's temporal bone might be a possible alternative. MATERIAL AND METHODS: Temporal bones of the lamb were dissected with a typical temporal bone lab drilling program. We included a mastoidectomy, endaural approaches, but also analyzed the outer appearance, the external ear canal and the hypotympanon. Some steps differed from preparation done in humans. The morphometric results were compared to

  5. Aggressive osteoblastoma in mastoid process of temporal bone with facial palsy

    Directory of Open Access Journals (Sweden)

    Manoj Jain

    2013-01-01

    Full Text Available Osteoblastoma is an uncommon primary bone tumor with a predilection for posterior elements of spine. Its occurrence in temporal bone and middle ear is extremely rare. Clinical symptoms are non-specific and cranial nerve involvement is uncommon. The cytomorphological features of osteoblastoma are not very well defined and the experience is limited to only few reports. We report an interesting and rare case of aggressive osteoblastoma, with progressive hearing loss and facial palsy, involving the mastoid process of temporal bone and middle ear along with the description of cyto-morphological features.

  6. Tympanic plate fractures in temporal bone trauma: prevalence and associated injuries.

    Science.gov (United States)

    Wood, C P; Hunt, C H; Bergen, D C; Carlson, M L; Diehn, F E; Schwartz, K M; McKenzie, G A; Morreale, R F; Lane, J I

    2014-01-01

    The prevalence of tympanic plate fractures, which are associated with an increased risk of external auditory canal stenosis following temporal bone trauma, is unknown. A review of posttraumatic high-resolution CT temporal bone examinations was performed to determine the prevalence of tympanic plate fractures and to identify any associated temporal bone injuries. A retrospective review was performed to evaluate patients with head trauma who underwent emergent high-resolution CT examinations of the temporal bone from July 2006 to March 2012. Fractures were identified and assessed for orientation; involvement of the tympanic plate, scutum, bony labyrinth, facial nerve canal, and temporomandibular joint; and ossicular chain disruption. Thirty-nine patients (41.3 ± 17.2 years of age) had a total of 46 temporal bone fractures (7 bilateral). Tympanic plate fractures were identified in 27 (58.7%) of these 46 fractures. Ossicular disruption occurred in 17 (37.0%). Fractures involving the scutum occurred in 25 (54.4%). None of the 46 fractured temporal bones had a mandibular condyle dislocation or fracture. Of the 27 cases of tympanic plate fractures, 14 (51.8%) had ossicular disruption (P = .016) and 18 (66.6%) had a fracture of the scutum (P = .044). Temporomandibular joint gas was seen in 15 (33%) but was not statistically associated with tympanic plate fracture (P = .21). Tympanic plate fractures are commonly seen on high-resolution CT performed for evaluation of temporal bone trauma. It is important to recognize these fractures to avoid the preventable complication of external auditory canal stenosis and the potential for conductive hearing loss due to a fracture involving the scutum or ossicular chain.

  7. Face and content validation of a virtual reality temporal bone simulator.

    Science.gov (United States)

    Arora, Asit; Khemani, Sam; Tolley, Neil; Singh, Arvind; Budge, James; Varela, David A Diaz Voss; Francis, Howard W; Darzi, Ara; Bhatti, Nasir I

    2012-03-01

    To validate the VOXEL-MAN TempoSurg simulator for temporal bone dissection. Prospective international study. Otolaryngology departments of 2 academic health care institutions in the United Kingdom and United States. Eighty-five subjects were recruited consisting of an experienced and referent group. Participants performed a standardized familiarization session and temporal bone dissection task. Realism, training effectiveness, and global impressions were evaluated across 21 domains using a 5-point Likert-type scale. A score of 4 was the minimum threshold for acceptability. The experienced group comprised 25 otolaryngology trainers who had performed 150 mastoid operations. The referent group comprised 60 trainees (mean otolaryngology experience of 2.9 years). Familiarization took longer in the experienced group (P = .01). User-friendliness was positively rated (mean score 4.1). Seventy percent of participants rated anatomical appearance as acceptable. Trainers rated drill ergonomics worse than did trainees (P = .01). Simulation temporal bone training scored highly (mean score 4.3). Surgical anatomy, drill navigation, and hand-eye coordination accounted for this. Trainees were more likely to recommend temporal bone simulation to a colleague than were trainers (P = .01). Transferability of skills to the operating room was undecided (mean score 3.5). Realism of the VOXEL-MAN virtual reality temporal bone simulator is suboptimal in its current version. Nonetheless, it represents a useful adjunct to existing training methods and is particularly beneficial for novice surgeons before performing cadaveric temporal bone dissection. Improvements in realism, specifically drill ergonomics and visual-spatial perception during deeper temporal bone dissection, are warranted.

  8. TEMPORAL MODELING OF DNA DEGRADATION IN BONE REMAINS

    Directory of Open Access Journals (Sweden)

    Andrei Stefan

    2012-06-01

    Full Text Available The aim of this study is to follow the changes that occur, in time, at DNA level and to establish an efficient and reliable protocol for ancestral DNA extraction from bones found in archaeological sites. To test whether the protocol is efficient and capable of yielding good quality DNA, extraction was first performed on fresh bones. The material consists of fresh pig (Sus scrofa and cow (Bos taurus bones that were grounded by using a drill operating at low speed. The bone powder was then incubated in lysis buffer in the presence of proteinase K. DNA isolation and purification were done by using the phenol:chloroform protocol and DNA was precipitated with absolute ethanol stored at -20oC. The extractions were carried out once every month for a total of four extractions

  9. Transparent model of temporal bone and vestibulocochlear organ made by 3D printing.

    Science.gov (United States)

    Suzuki, Ryoji; Taniguchi, Naoto; Uchida, Fujio; Ishizawa, Akimitsu; Kanatsu, Yoshinori; Zhou, Ming; Funakoshi, Kodai; Akashi, Hideo; Abe, Hiroshi

    2018-01-01

    The vestibulocochlear organ is composed of tiny complex structures embedded in the petrous part of the temporal bone. Landmarks on the temporal bone surface provide the only orientation guide for dissection, but these need to be removed during the course of dissection, making it difficult to grasp the underlying three-dimensional structures, especially for beginners during gross anatomy classes. We report herein an attempt to produce a transparent three-dimensional-printed model of the human ear. En bloc samples of the temporal bone from donated cadavers were subjected to computed tomography (CT) scanning, and on the basis of the data, the surface temporal bone was reconstructed with transparent resin and the vestibulocochlear organ with white resin to create a 1:1.5 scale model. The carotid canal was stuffed with red cotton, and the sigmoid sinus and internal jugular vein were filled with blue clay. In the inner ear, the internal acoustic meatus, cochlea, and semicircular canals were well reconstructed in detail with white resin. The three-dimensional relationships of the semicircular canals, spiral turns of the cochlea, and internal acoustic meatus were well recognizable from every direction through the transparent surface resin. The anterior semicircular canal was obvious immediately beneath the arcuate eminence, and the topographical relationships of the vestibulocochlear organ and adjacent great vessels were easily discernible. We consider that this transparent temporal bone model will be a very useful aid for better understanding of the gross anatomy of the vestibulocochlear organ.

  10. Temporal Bone Osteomyelitis: The Relationship with Malignant Otitis Externa, the Diagnostic Dilemma, and Changing Trends

    Directory of Open Access Journals (Sweden)

    Jia-Cheng Chen

    2014-01-01

    Full Text Available Fifty-five patients hospitalized for osteomyelitis of the temporal bone between 1990 and 2011 were divided into two study groups: group 1 was patients collected from 1990 to 2001 and group 2 was composed of patients between 2002 and 2011. Clinical diagnostic criteria and epidemiologic data were analyzed to illustrate the altering features of osteomyelitis of the temporal bone. Group 1 patients were characterized by high prevalence of diabetes and more commonly suffered from otalgia, otitis externa and granulation tissue in the external auditory canal and higher positive culture for Pseudomonas aeruginosa. Noticeable changing trends were found between both groups, including declining prevalence of diabetes, fewer patients complaining of pain or presenting with otitis externa, and canal granulation, and increased variety of pathogens in group 2. We should highlight the index of clinical suspicion for osteomyelitis of the temporal bone, even in nondiabetic or immunocompetent patients. Painless otorrhea patients were also at risk of osteomyelitis of the temporal bone, especially patients with previous otologic operation. Increased multiplicity of pathogens amplified the difficulty of diagnosis for osteomyelitis of the temporal bone.

  11. Evaluation of a haptics-based virtual reality temporal bone simulator for anatomy and surgery training.

    Science.gov (United States)

    Fang, Te-Yung; Wang, Pa-Chun; Liu, Chih-Hsien; Su, Mu-Chun; Yeh, Shih-Ching

    2014-02-01

    Virtual reality simulation training may improve knowledge of anatomy and surgical skills. We evaluated a 3-dimensional, haptic, virtual reality temporal bone simulator for dissection training. The subjects were 7 otolaryngology residents (3 training sessions each) and 7 medical students (1 training session each). The virtual reality temporal bone simulation station included a computer with software that was linked to a force-feedback hand stylus, and the system recorded performance and collisions with vital anatomic structures. Subjects performed virtual reality dissections and completed questionnaires after the training sessions. Residents and students had favorable responses to most questions of the technology acceptance model (TAM) questionnaire. The average TAM scores were above neutral for residents and medical students in all domains, and the average TAM score for residents was significantly higher for the usefulness domain and lower for the playful domain than students. The average satisfaction questionnaire for residents showed that residents had greater overall satisfaction with cadaver temporal bone dissection training than training with the virtual reality simulator or plastic temporal bone. For medical students, the average comprehension score was significantly increased from before to after training for all anatomic structures. Medical students had significantly more collisions with the dura than residents. The residents had similar mean performance scores after the first and third training sessions for all dissection procedures. The virtual reality temporal bone simulator provided satisfactory training for otolaryngology residents and medical students. Copyright © 2013. Published by Elsevier Ireland Ltd.

  12. Evaluating the Effect of Virtual Reality Temporal Bone Simulation on Mastoidectomy Performance: A Meta-analysis.

    Science.gov (United States)

    Lui, Justin T; Hoy, Monica Y

    2017-06-01

    Background The increasing prevalence of virtual reality simulation in temporal bone surgery warrants an investigation to assess training effectiveness. Objectives To determine if temporal bone simulator use improves mastoidectomy performance. Data Sources Ovid Medline, Embase, and PubMed databases were systematically searched per the PRISMA guidelines. Review Methods Inclusion criteria were peer-reviewed publications that utilized quantitative data of mastoidectomy performance following the use of a temporal bone simulator. The search was restricted to human studies published in English. Studies were excluded if they were in non-peer-reviewed format, were descriptive in nature, or failed to provide surgical performance outcomes. Meta-analysis calculations were then performed. Results A meta-analysis based on the random-effects model revealed an improvement in overall mastoidectomy performance following training on the temporal bone simulator. A standardized mean difference of 0.87 (95% CI, 0.38-1.35) was generated in the setting of a heterogeneous study population ( I 2 = 64.3%, P virtual reality simulation temporal bone surgery studies, meta-analysis calculations demonstrate an improvement in trainee mastoidectomy performance with virtual simulation training.

  13. Unbiased Stereologic Estimation of the Spatial Distribution of Paget’s Disease in the Human Temporal Bone

    DEFF Research Database (Denmark)

    Bloch, Sune Land; Sørensen, Mads Sølvsten

    2014-01-01

    remodeling around the inner ear space and to compare it with that of otosclerosis in a contemporary context of temporal bone dynamics. MATERIALS AND METHODS: From the temporal bone collection of Massachusetts Eye and Ear Infirmary, 15 of 29 temporal bones with Paget's disease were selected to obtain...... an independent sample. All volume distributions were obtained along the normal axis of capsular bone remodeling activity by the use of vector-based stereology. RESULTS: Pagetic bone remodeling was distributed centrifugally around the inner ear space at the individual and the general level. This pattern...

  14. Bilateral Facial Paralysis Caused by Bilateral Temporal Bone Fracture: A Case Report and a Literature Review

    Directory of Open Access Journals (Sweden)

    Sultan Şevik Eliçora

    2015-01-01

    Full Text Available Bilateral facial paralysis caused by bilateral temporal bone fracture is a rare clinical entity, with seven cases reported in the literature to date. In this paper, we describe a 40-year-old male patient with bilateral facial paralysis and hearing loss that developed after an occupational accident. On physical examination, House-Brackmann (HB facial paralysis of grade 6 was observed on the right side and HB grade 5 paralysis on the left. Upon temporal bone computed tomography (CT examination, a fracture line exhibiting transverse progression was observed in both petrous temporal bones. Our patient underwent transmastoid facial decompression surgery of the right ear. The patient refused a left-side operation. Such patients require extensive monitoring in intensive care units because the presence of multiple injuries means that facial functions are often very difficult to evaluate. Therefore, delays may ensue in both diagnosis and treatment of bilateral facial paralysis.

  15. Cetuximab with radiotherapy as an alternative treatment for advanced squamous cell carcinoma of the temporal bone.

    Science.gov (United States)

    Ebisumoto, Koji; Okami, Kenji; Hamada, Masashi; Maki, Daisuke; Sakai, Akihiro; Saito, Kosuke; Shimizu, Fukuko; Kaneda, Shoji; Iida, Masahiro

    2018-06-01

    The prognosis of advanced temporal bone cancer is poor, because complete surgical resection is difficult to achieve. Chemoradiotherapy is one of the available curative treatment options; however, its systemic effects on the patient restrict the use of this treatment. A 69-year-old female (who needed peritoneal dialysis) presented at our clinic with T4 left external auditory canal cancer and was treated with cetuximab plus radiotherapy (RT). The primary lesion showed complete response. The patient is currently alive with no evidence of disease two years after completion of the treatment and does not show any late toxicity. This is the first advanced temporal bone cancer patient treated with RT plus cetuximab. Cetuximab plus RT might be a treatment alternative for patients with advanced temporal bone cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. CT diagnosis and differential diagnosis of otodystrophic lesions of the temporal bone

    International Nuclear Information System (INIS)

    D'Archambeau, O.; Parizel, P.M.; Schepper, A.M. De; Koekelkoren, E.; Van De Heyning, P.

    1990-01-01

    The purpose of this study was to assess the diagnostic and differential diagnostic value of high-resolution computed tomography in the evaluation of temporal-bone dystrophies. The study group included 55 patients with osseous abnormalities of the temporal bone in general, and the labyrinthine capsule in particular. In 27 patients the CT scan revealed evidence of otodystrophic lesions. The CT findings in patients with otosclerosis (21 patients), osteogenesis imperfecta (two patients), fibrous dysplasia (one patient). Paget's disease (one patient) and osteoporosis (two patients) are described. The CT scans of 17 patients revealed secondary osseous lesions due to metastasis (five patients), post-inflammatory changes (10 patients) or labyrinthitis ossificans (two patients). Normal variants and congenital mineralization defects were diagnosed in nine patients, Down's syndrome in two. Our results indicate the importance of high-resolution computed tomography as the primary imaging modality in evaluating osseous lesions of the temporal bone and labyrinth. (author). 14 refs.; 13 figs; 2 tabs

  17. Spatial and temporal variations of the callus mechanical properties during bone transport

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Macias, J.; Reina-Romo, E.; Pajares, A.; Miranda, P.; Dominguez, J.

    2016-07-01

    Nanoindentation allows obtaining the elastic modulus and the hardness of materials point by point. This technique has been used to assess the mechanical propeties of the callus during fracture healing. However, as fas as the authors know, the evaluation of mechanical properties by this technique of the distraction and the docking-site calluses generated during bone transport have not been reported yet. Therefore, the aim of this work is using nanoindentation to assess the spatial and temporal variation of the elastic modulus of the woven bone generated during bone transport. Nanoindentation measurements were carried out using 6 samples from sheep sacrificed at different stages of the bone transport experiments. The results obtained show an important heterogeneity of the elastic modulus of the woven bone without spatial trends. In the case of temporal variation, a clear increase of the mean elastic modulus with time after surgery was observed (from 7±2GPa 35 days after surgery to 14±2GPa 525 days after surgery in the distraction callus and a similar increase in the docking site callus). Comparison with the evolution of the elastic modulus in the woven bone generated during fracture healing shows that mechanical properties increase slower in the case of the woven bone generated during bone transport. (Author)

  18. Facial nerve palsy associated with a cystic lesion of the temporal bone.

    Science.gov (United States)

    Kim, Na Hyun; Shin, Seung-Ho

    2014-03-01

    Facial nerve palsy results in the loss of facial expression and is most commonly caused by a benign, self-limiting inflammatory condition known as Bell palsy. However, there are other conditions that may cause facial paralysis, such as neoplastic conditions of the facial nerve, traumatic nerve injury, and temporal bone lesions. We present a case of facial nerve palsy concurrent with a benign cystic lesion of the temporal bone, adjacent to the tympanic segment of the facial nerve. The patient's symptoms subsided after facial nerve decompression via a transmastoid approach.

  19. Temporal bone fracture following blunt trauma caused by a flying fish.

    Science.gov (United States)

    Goldenberg, D; Karam, M; Danino, J; Flax-Goldenberg, R; Joachims, H Z

    1998-10-01

    Blunt trauma to the temporal region can cause fracture of the skull base, loss of hearing, vestibular symptoms and otorrhoea. The most common causes of blunt trauma to the ear and surrounding area are motor vehicle accidents, violent encounters, and sports-related accidents. We present an obscure case of a man who was struck in the ear by a flying fish while wading in the sea with resulting temporal bone fracture, sudden deafness, vertigo, cerebrospinal fluid otorrhoea, and pneumocephalus.

  20. Validation of exposure visualization and audible distance emission for navigated temporal bone drilling in phantoms.

    Directory of Open Access Journals (Sweden)

    Eduard H J Voormolen

    Full Text Available BACKGROUND: A neuronavigation interface with extended function as compared with current systems was developed to aid during temporal bone surgery. The interface, named EVADE, updates the prior anatomical image and visualizes the bone drilling process virtually in real-time without need for intra-operative imaging. Furthermore, EVADE continuously calculates the distance from the drill tip to segmented temporal bone critical structures (e.g. the sigmoid sinus and facial nerve and produces audiovisual warnings if the surgeon drills in too close vicinity. The aim of this study was to evaluate the accuracy and surgical utility of EVADE in physical phantoms. METHODOLOGY/PRINCIPAL FINDINGS: We performed 228 measurements assessing the position accuracy of tracking a navigated drill in the operating theatre. A mean target registration error of 1.33±0.61 mm with a maximum error of 3.04 mm was found. Five neurosurgeons each drilled two temporal bone phantoms, once using EVADE, and once using a standard neuronavigation interface. While using standard neuronavigation the surgeons damaged three modeled temporal bone critical structures. No structure was hit by surgeons utilizing EVADE. Surgeons felt better orientated and thought they had improved tumor exposure with EVADE. Furthermore, we compared the distances between surface meshes of the virtual drill cavities created by EVADE to actual drill cavities: average maximum errors of 2.54±0.49 mm and -2.70±0.48 mm were found. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that EVADE gives accurate feedback which reduces risks of harming modeled critical structures compared to a standard neuronavigation interface during temporal bone phantom drilling.

  1. Displasia fibrosa do osso temporal: relato de dois casos Fibrous dysplasia of the temporal bone: report of two cases

    Directory of Open Access Journals (Sweden)

    Roberto Claudio B. Oliveira

    2004-10-01

    Full Text Available A displasia fibrosa do osso temporal é uma doença de etiologia ainda controversa, manifestando-se principalmente por estenose progressiva do conduto auditivo externo e pela perda condutiva da audição. Outras manifestações incluem abaulamento na região temporal ou retroauricular, otorréia, otalgia e disacusia sensório-neural. A incidência é maior no sexo masculino e acomete principalmente a raça branca. O exame radiológico característico demonstra um aspecto de "vidro-fosco" homogêneo envolvido por uma concha de tecido cortical denso, embora existam outros padrões radiológicos desta enfermidade. O exame microscópico demonstra um trabeculado ósseo semelhante aos caracteres chineses. Este estudo relata dois casos de displasia fibrosa do osso temporal que se destacam, pois ultrapassaram o osso temporal, acometendo a região zigomática, sendo que no segundo caso houve também comprometimento do osso esfenóide e o pterigóide. Os pacientes foram submetidos à mastoidectomia radical modificada e tiveram boa evolução.Fibrous dysplasia of the temporal bone (FDTB is a disorder which etiology is still controversial. Its main clinical feature is a progressive narrowing of the external auditory canal following by conductive hearing loss. Temporal or retroauricular enlargement, ear discharge, otalgia, and sensorineural hearing loss are additional findings. Women and Caucasians are more affected. The prominent finding is a homogeneous radiodense "grounded glass" like image shell surrounded by dense cortical tissue. However, other radiological patterns of this disease may be displayed. Microscopically, a trabecular of bone in "Chinese letter" configuration is found. The two cases of FDTB herein reported are particularly special for a far beyond temporal commitment reaching the zygomatic area in the first case and sphenoid and pterygoid bones in the second one. This infrequent clinical feature with unusual radiological findings made these

  2. Linear pneumatic actuator

    Directory of Open Access Journals (Sweden)

    Avram Mihai

    2017-01-01

    Full Text Available The paper presents a linear pneumatic actuator with short working stroke. It consists of a pneumatic motor (a simple stroke cylinder or a membrane chamber, two 2/2 pneumatic distributors “all or nothing” electrically commanded for controlling the intake/outtake flow to/from the active chamber of the motor, a position transducer and a microcontroller. There is also presented the theoretical analysis (mathematical modelling and numerical simulation accomplished.

  3. Linear pneumatic actuator

    OpenAIRE

    Avram Mihai; Niţu Constantin; Bucşan Constantin; Grămescu Bogdan

    2017-01-01

    The paper presents a linear pneumatic actuator with short working stroke. It consists of a pneumatic motor (a simple stroke cylinder or a membrane chamber), two 2/2 pneumatic distributors “all or nothing” electrically commanded for controlling the intake/outtake flow to/from the active chamber of the motor, a position transducer and a microcontroller. There is also presented the theoretical analysis (mathematical modelling and numerical simulation) accomplished.

  4. Laser-cutting pneumatics

    OpenAIRE

    Groenhuis, Vincent; Stramigioli, Stefano

    2016-01-01

    Pneumatic devices require tight tolerances to keep them leak-free. Specialized companies offer various off-the-shelf devices, while these work well for many applications, there are also situations where custom design and production of pneumatic parts are desired. Cost efficiency, design flexibility, rapid prototyping, and MRI compatibility requirements are reasons why we investigated a method to design and produce different pneumatic devices using a laser cutter from acrylic, acetal, and rubb...

  5. Face and content validation of a novel three-dimensional printed temporal bone for surgical skills development.

    Science.gov (United States)

    Da Cruz, M J; Francis, H W

    2015-07-01

    To assess the face and content validity of a novel synthetic, three-dimensional printed temporal bone for surgical skills development and training. A synthetic temporal bone was printed using composite materials and three-dimensional printing technology. Surgical trainees were asked to complete three structured temporal bone dissection exercises. Attitudes and impressions were then assessed using a semi-structured questionnaire. Previous cadaver and real operating experiences were used as a reference. Trainees' experiences of the synthetic temporal bone were analysed in terms of four domains: anatomical realism, usefulness as a training tool, task-based usefulness and overall reactions. Responses across all domains indicated a high degree of acceptance, suggesting that the three-dimensional printed temporal bone was a useful tool in skills development. A sophisticated three-dimensional printed temporal bone that demonstrates face and content validity was developed. The efficiency in cost savings coupled with low associated biohazards make it likely that the printed temporal bone will be incorporated into traditional temporal bone skills development programmes in the near future.

  6. Incidental internal carotid artery calcifications on temporal bone CT in children

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Bernadette; Jones, Blaise [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Blackham, Aaron [University of Cincinnati College of Medicine, Cincinnati, OH (United States)

    2007-02-15

    Incidental internal carotid artery (ICA) calcifications are occasionally noted on CT images of the brain and temporal bone. In adults, incidental calcifications have been correlated with increased incidence of hypercholesterolemia, cardiac disease, diabetes and carotid stenosis. To determine the incidence of incidental calcifications of the carotid siphon on temporal bone CT in children. We retrospectively reviewed 24 months of consecutive temporal bone CT examinations in children aged 18 years and younger. CT examinations on 663 patients were reviewed and the presence or absence of ICA calcifications was ranked as absent, questionable or definitive. In patients in whom definitive calcifications were identified, hospital charts were reviewed for evidence of diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, hyperlipidemia and chronic renal disease as potential causes of early atherosclerosis. Of the 663 patients, 25% had definitive calcifications within the wall of the ICA: 6% of children younger than 2 years and 28% of children 12-19 years of age. Incidentally noted ICA calcifications are a common finding on temporal bone CT in children, most likely a physiologic response to turbulent flow at natural bends in the artery rather than secondary to underlying disease predisposing to early atherosclerotic calcification. (orig.)

  7. Anatomic variations of the cochlea and relations to other temporal bone structures

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, P.; Muren, C. (Akademiska Sjukhuset, Uppsala (Sweden). Dept. of Diagnostic Radiology Sabbatsberg' s Sjukhus, Stockholm (Sweden). Dept. of Diagnostic Radiology)

    1990-09-01

    The size and shape of the human cochlea and the normal ranges of variation of its dimensions were evaluated in 95 plastic casts, prepared from temporal bone specimens. The normal range of variation is fairly small, and is not age-dependent. Obvious digression from this range, associated with pertinent clinical symptoms, indicates an abnormality. (orig./MG).

  8. High-resolution CT of temporal bone trauma: review of 38 cases

    International Nuclear Information System (INIS)

    Hiroual, M.R.; Zougarhi, A.; Cherif Idrissi El Ganouni, N.; Essadki, O.; Ousehal, A.; Tijani Adil, O.; Maliki, O.; Aderdour, L.; Raji, A.

    2010-01-01

    Purpose Temporal bone trauma is frequent but difficult to assess due to the diversity of clinical presentations and complex anatomy. We have sought to assess the different types of fractures and complications on high-resolution CT. Materials and methods Descriptive retrospective study over a 24 month period performed in the ENT radiology section of the Mohammed 6 university medical center in Marrakech. A total of 38 cases of temporal bone trauma were reviewed. All patients underwent ENT evaluation and high-resolution CT of the temporal bone using 1 mm axial and coronal sections. Results Mean patient age was 33 years (range: 14-55 years) with male predominance (sex ratio: 36/2). Clinical symptoms were mainly otorrhagia and conductive hearing loss. Oblique extra-labyrinthine fractures were most frequent. Two cases of pneumo-labyrinth were noted. Management was conservative in most cases with deafness in 3 cases. Conclusion High-resolution CT of the temporal bone provides accurate depiction of lesions explaining the clinical symptoms and helps guide management. MRI is complimentary to further assess the labyrinth and VII-VIII nerve complex. (author)

  9. Interactive atlas using web browser: CT and MRI of the temporal bone

    International Nuclear Information System (INIS)

    Chung, Eun Chul; Youn, Eun Kyung; Lee, Young Uk

    2000-01-01

    The purposes of this study were to construct an interactive atlas of the temporal bone using a web-browser and to provide a template for web-based teaching files, using free and shared applets and scripts on the internet. HRCT and MR images of the temporal bone including its normal anatomy, tumors, trauma, inflammation, anomalies and vascular diseases were used in this study. Acquired radiologic images were transformed to GIF/JPG formats and to achieve appropriate image quality, were retouched. Text and image files of normal anatomy and diseases were written by HTML. JavaScript and applets were inserted in the HTML files for the interactive display of images and texts. In order to review anatomic features and diseases, a search index was also attached to the last part of the file. Using interactive images and text, temporal bone anatomy and disorders were displayed. Scripts and applets were also useful for indicating specific points of interest when a mouse was placed over the anatomic sites. The atlas may be viewed in the form of a CD-ROM, or via the internet using any computer platform or web-browser. This web-based teaching file of the temporal bone offers dynamic and interactive education. It can be usefully employed as a template for the production of interactive educational materials, offering JavaScript and providing suitable input for classes. It can replace texts and imaging contents. (author)

  10. Incidental internal carotid artery calcifications on temporal bone CT in children

    International Nuclear Information System (INIS)

    Koch, Bernadette; Jones, Blaise; Blackham, Aaron

    2007-01-01

    Incidental internal carotid artery (ICA) calcifications are occasionally noted on CT images of the brain and temporal bone. In adults, incidental calcifications have been correlated with increased incidence of hypercholesterolemia, cardiac disease, diabetes and carotid stenosis. To determine the incidence of incidental calcifications of the carotid siphon on temporal bone CT in children. We retrospectively reviewed 24 months of consecutive temporal bone CT examinations in children aged 18 years and younger. CT examinations on 663 patients were reviewed and the presence or absence of ICA calcifications was ranked as absent, questionable or definitive. In patients in whom definitive calcifications were identified, hospital charts were reviewed for evidence of diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, hyperlipidemia and chronic renal disease as potential causes of early atherosclerosis. Of the 663 patients, 25% had definitive calcifications within the wall of the ICA: 6% of children younger than 2 years and 28% of children 12-19 years of age. Incidentally noted ICA calcifications are a common finding on temporal bone CT in children, most likely a physiologic response to turbulent flow at natural bends in the artery rather than secondary to underlying disease predisposing to early atherosclerotic calcification. (orig.)

  11. Determination of a facial nerve safety zone for navigated temporal bone surgery

    NARCIS (Netherlands)

    Voormolen, E.H.J.; Stralen, van M.; Woerdeman, P.A.; Pluim, J.P.W.; Noordmans, H.J.; Viergever, M.A.; Regli, L.; Berkelbach van der Sprenkel, J.W.

    2012-01-01

    Transtemporal approaches require surgeons to drill the temporal bone to expose target lesions while avoiding the critical structures within it, such as the facial nerve and other neurovascular structures. We envision a novel protective neuronavigation system that continuously calculates the drill

  12. High-resolution computed tomography of the temporal bone. Part 1.: normal anatomy

    International Nuclear Information System (INIS)

    Grzegorzewski, M.; Boron, Z.; Burzynska-Makuch, M.

    1995-01-01

    Normal anatomy of the temporal bone in transverse and coronal sections was presented. CT studies were performed using high-resolution program. The images of an asymptomatic ear of 2 patients were selected from 68 cases examined on account of various otological diseases. All the sections showed as many as 68 anatomic structures. (author)

  13. Transverse axial plane anatomy of the temporal bone employing high spatial resolution computed tomography

    International Nuclear Information System (INIS)

    Russell, E.J.; Koslow, M.; Lasjaunias, P.; Bergeron, R.T.; Chase, N.

    1982-01-01

    Anatomical relationships of temporal bone structures are demonstrated by thin section edge detection computed tomography. Many otic structures are best appreciated in axial view, but reorientation to anatomy as seen in this plane is needed for optimal diagnosis. A level by level review of key structure is presented toward this end. The limitations and advantages of computed tomography are discussed. (orig.)

  14. Benign osteoblastoma of the temporal bone: case report and literature review

    Directory of Open Access Journals (Sweden)

    Yoo, Hea Jung

    2008-09-01

    Full Text Available Introduction: Osteoblastoma is defined as a lesion of bone, which is rich in osteoblasts, well-vascularized, and affects mainly the spinal cord. Although it is benign, it presents malignant features and simulates osteosarcoma. It affects mainly young adults between 20 and 40 years old. It rarely compromises the temporal bone. Objective: To present a rare case in the temporal bone with clinical malignant features whose the anatomopathological study has revealed to be a benign tumor. Method: The patient presented a tumor which affected the middle ear cleft, the mastoid, and the right middle fossa. The patient underwent a surgery and, in association with otorhinolaryngology, the tumor was completely dried out from the middle fossa and the middle ear. Fascia lata was used to repair the dural impairment and an acrylic plate was used to cover the bone impairment. Result: Post-surgery evolved positively, however the acrylic plate has moved itself and has stenosed the right external acoustic meato, which had to be removed 3 years later. The patient has had a good followup, which is still being carried through. Conclusion: Osteoblastoma is a multiform tumor that might affect the temporal bone with malignant features, which simulates osteosarcoma, but, in histological terms, it does not present any malignant signals. However, there is a need for a long post-surgery follow-up.

  15. Creation of a 3D printed temporal bone model from clinical CT data.

    Science.gov (United States)

    Cohen, Joss; Reyes, Samuel A

    2015-01-01

    Generate and describe the process of creating a 3D printed, rapid prototype temporal bone model from clinical quality CT images. We describe a technique to create an accurate, alterable, and reproducible rapid prototype temporal bone model using freely available software to segment clinical CT data and generate three different 3D models composed of ABS plastic. Each model was evaluated based on the appearance and size of anatomical structures and response to surgical drilling. Mastoid air cells had retained scaffolding material in the initial versions. This required modifying the model to allow drainage of the scaffolding material. External auditory canal dimensions were similar to those measured from the clinical data. Malleus, incus, oval window, round window, promontory, horizontal semicircular canal, and mastoid segment of the facial nerve canal were identified in all models. The stapes was only partially formed in two models and absent in the third. Qualitative feel of the ABS plastic was softer than bone. The pate produced by drilling was similar to bone dust when appropriate irrigation was used. We present a rapid prototype temporal bone model made based on clinical CT data using 3D printing technology. The model can be made quickly and inexpensively enough to have potential applications for educational training. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Theoretical analysis of the spatio-temporal structure of bone multicellular units

    International Nuclear Information System (INIS)

    Buenzli, P R; Pivonka, P; Gardiner, B S; Smith, D W; Dunstan, C R; Mundy, G R

    2010-01-01

    Bone multicellular units (BMUs) maintain the viability of the skeletal tissue by coordinating locally the sequence of bone resorption and bone formation performed by cells of the osteoclastic and osteoblastic lineage. Understanding the emergence and the net bone balance of such structured microsystems out of the complex network of biochemical interactions between bone cells is fundamental for many bone-related diseases and the evaluation of fracture risk. Based on current experimental knowledge, we propose a spatio-temporal continuum model describing the interactions of osteoblastic and osteoclastic cells. We show that this model admits travelling-wave-like solutions with well-confined cell profiles upon specifying external conditions mimicking the environment encountered in cortical bone remodelling. The shapes of the various cell concentration profiles within this travelling structure are intrinsically linked to the parameters of the model such as differentiation, proliferation, and apoptosis rates of bone cells. The internal structure of BMUs is reproduced, allowing for experimental calibration. The spatial distribution of the key regulatory factors can also be exhibited, which in diseased states could give hints as to the biochemical agent most accountable for the disorder.

  17. Temporal Bone Fractures and its Classification: Retrospective Study of Incidence, Causes, Clinical Features, Complications and Outcome

    Directory of Open Access Journals (Sweden)

    Umamaheshwari Basavaraju

    2017-10-01

    Full Text Available Introduction: Temporal bone fracture is usually associated with high energy head injury and can cause potentially severe complications. Immediate detection of temporal bone fracture and its complications helps in providing early and effective treatment, which if left untreated can have drastic consequences. Aim: The main objective of the study is to document the frequency and most prevalent type of temporal bone fracture, co-existing complications and to establish association between them. Materials and Methods: One year (2015-2016 retrospective study of head injured patients presented to the Emergency Department, Mysore Medical College And Research Institute was conducted. Age and gender distribution, cause of injury, radiological findings, otorhinolaryngological clinical presentations and treatment given were analyzed. The results were tabulated and were evaluated by Microsoft Excel 2013. Results: Out of 1450 patients evaluated for head injury 154 patients were positive for temporal bone fracture. Incidence of the study was 10.6%. Majority of the patients were male (66.2% and were between 30 to 40 years (50.1%. The major cause of injury was motor vehicle accidents (84.48%. Right side was involved (58.4% more than the left side (41.5%. Most common clinical presentation was otorrhea 68.8%, followed by otalgia (35.04% and otorhinorrhea (24.67%. Longitudinal type fracture was most frequent 56.25%. Otic capsule involvement was present in 35.93%. Most of the fractures were managed conservatively whereas surgery was required in 12 patients (7.7%. Conclusion: Temporal bone fractures were frequently associated with severe traumatic brain injury leading to serious long term morbidity and sequelae. CT-scan is of utmost importance in detection of fractures and its complications.

  18. Successful Function-Preserving Therapy for Chondroblastoma of the Temporal Bone Involving the Temporomandibular Joint

    Directory of Open Access Journals (Sweden)

    Junkichi Yokoyama

    2011-02-01

    Full Text Available We present a case involving a late diagnosis of chondroblastoma of the temporal skull base involving the temporomandibular joint (TMJ. Following an initial misdiagnosis and unsuccessful treatment over a period of 5 years, the patient was referred to our department for further evaluation and possible surgical intervention for occlusal abnormalities, trismus, clicking of the TMJ, and hearing impairment. Based on preoperative immunochemical studies showing positive reaction of multinucleated giant cells for S-100 protein, the final diagnosis was chondroblastoma. The surgical approach – postauricular incision and total parotidectomy, with complete removal of the temporal bone, including the TMJ via the extended middle fossa – was successful in preserving facial nerves and diminishing clinical manifestations. This study highlights a misdiagnosed case in an effort to underline the importance of medical examinations and accurate differential diagnosis in cases involving any tumor mass in the temporal bone.

  19. Rotary pneumatic valve

    Science.gov (United States)

    Hardee, Harry C.

    1991-01-01

    A rotary pneumatic valve which is thrust balanced and the pneumatic pressure developed produces only radial loads on the valve cylinder producing negligible resistance and thus minimal torque on the bearings of the valve. The valve is multiplexed such that at least two complete switching cycles occur for each revolution of the cylinder spindle.

  20. Laser-cutting pneumatics

    NARCIS (Netherlands)

    Groenhuis, Vincent; Stramigioli, Stefano

    Pneumatic devices require tight tolerances to keep them leak-free. Specialized companies offer various off-the-shelf devices, while these work well for many applications, there are also situations where custom design and production of pneumatic parts are desired. Cost efficiency, design flexibility,

  1. Large capillary hemangioma of the temporal bone with a dural tail sign: A case report

    KAUST Repository

    YANG, GUANG

    2014-05-13

    The present study reports a rare case of large capillary hemangioma of the temporal bone with a dural tail sign. A 57-year-old female presented with pulsatile tinnitus and episodic vertigo associated with a ten-year history of an intermittent faint headache. Magnetic resonance imaging revealed a mass in the right petrous bone, which was hypointense on T1-weighted images and heterogeneously hyperintense on T2-weighted images, and showed a dural tail sign following gadolinium administration. Pre-operatively, this tumor was believed to be a meningioma. During surgery, the vascular tumor was removed by a modified pterional approach. A histopathological examination indicated that the tumor was a capillary hemangioma. Although intraosseous capillary hemangiomas are rare, they most frequently affect the temporal bone. Hemangiomas of the temporal bone may mimic other more common basal tumors. The diagnosis is most often made during surgical resection. The dural tail sign is not specific for meningioma, as it also occurs in other intracranial or extracranial tumors. The treatment of intratemporal hemangiomas is complete surgical excision, with radiotherapy used for unresectable lesions. To the best of our knowledge, the present study is the fourth case of intraosseous intracranial capillary hemangioma, but the largest intratemporal hemangioma to be reported in the literature to date.

  2. Large capillary hemangioma of the temporal bone with a dural tail sign: A case report

    KAUST Repository

    YANG, GUANG; LI, CHENGUANG; CHEN, XIN; LIU, YAOHUA; HAN, DAYONG; Gao, Xin; KAWAMOTO, KEIJI; ZHAO, SHIGUANG

    2014-01-01

    The present study reports a rare case of large capillary hemangioma of the temporal bone with a dural tail sign. A 57-year-old female presented with pulsatile tinnitus and episodic vertigo associated with a ten-year history of an intermittent faint headache. Magnetic resonance imaging revealed a mass in the right petrous bone, which was hypointense on T1-weighted images and heterogeneously hyperintense on T2-weighted images, and showed a dural tail sign following gadolinium administration. Pre-operatively, this tumor was believed to be a meningioma. During surgery, the vascular tumor was removed by a modified pterional approach. A histopathological examination indicated that the tumor was a capillary hemangioma. Although intraosseous capillary hemangiomas are rare, they most frequently affect the temporal bone. Hemangiomas of the temporal bone may mimic other more common basal tumors. The diagnosis is most often made during surgical resection. The dural tail sign is not specific for meningioma, as it also occurs in other intracranial or extracranial tumors. The treatment of intratemporal hemangiomas is complete surgical excision, with radiotherapy used for unresectable lesions. To the best of our knowledge, the present study is the fourth case of intraosseous intracranial capillary hemangioma, but the largest intratemporal hemangioma to be reported in the literature to date.

  3. Case analysis of temporal bone lesions with facial paralysis as main manifestation and literature review.

    Science.gov (United States)

    Chen, Wen-Jing; Ye, Jing-Ying; Li, Xin; Xu, Jia; Yi, Hai-Jin

    2017-08-23

    This study aims to discuss clinical characteristics, image manifestation and treatment methods of temporal bone lesions with facial paralysis as the main manifestation for deepening the understanding of such type of lesions and reducing erroneous and missed diagnosis. The clinical data of 16 patients with temporal bone lesions and facial paralysis as main manifestation, who were diagnosed and treated from 2009 to 2016, were retrospectively analyzed. Among these patients, six patients had congenital petrous bone cholesteatoma (PBC), nine patients had facial nerve schwannoma, and one patient had facial nerve hemangioma. All the patients had an experience of long-term erroneous diagnosis. The lesions were completely excised by surgery. PBC and primary facial nerve tumors were pathologically confirmed. Facial-hypoglossal nerve anastomosis was performed on two patients. HB grade VI was recovered to HB grade V in one patient. The anastomosis failed due to severe facial nerve fibrosis in one patient. Hence, HB remained at grade VI. Postoperative recovery was good for all patients. No lesion recurrence was observed after 1-6 years of follow-up. For the patients with progressive or complete facial paralysis, imaging examination should be perfected in a timely manner. Furthermore, PBC, primary facial nerve tumors and other temporal bone space-occupying lesions should be eliminated. Lesions should be timely detected and proper intervention should be conducted, in order to reduce operation difficulty and complications, and increase the opportunity of facial nerve function reconstruction.

  4. The clinical significance of temporal bone CT with regard to hearing preservation in acoustic neurinoma removal

    International Nuclear Information System (INIS)

    Umezu, Hiromichi; Seki, Yojirou; Aiba, Tadashi

    1988-01-01

    Since Rand and Kurze discussed the possibility of the anatomic preservation of the cochlear nerve via the posterior fossa transmeatal approach for the acoustic neurinoma, there have been increasingly many reports on the preservation of cochlear nerve function. With recent advances in diagnostic tools, today's neurosurgeon is able to make an earlier and more precise diagnosis of acoustic neurinomas even when the patient has good hearing. If useful hearing is to be kept, the cochlear nerve and blood supply of the labyrinth have to be preserved. In addition, surgical entry into the labyrinth, upon the removal of the posterior wall of the internal auditory canal, must be avoided, since it is likely to result in permanent hearing loss. Because of its superior contrast and spatial resolution, thin-section and high-resolution computed tomography of the temporal bone has the great advantage of demonstrating the exact relationship of the internal auditory canal to the posterior semicircular canal, the vestibule, and the common crus. In this study, thin-section, high-resolution computed tomography of the temporal bone was performed in 11 cases of acoustic neurinoma pre- and postoperatively. At operation, the lateral limit of the bone removal of the posterior internal auditory canal was determined on the basis of preoperative computed tomography of the temporal bone. As a result, inadvertent entry into the labyrinth was avoided, and useful hearing was preserved in 8 cases. In order to preserve useful hearing following total tumor removal, it is essential to plan the operative strategy meticulously on the basis of the findings of the preoperative investigation, Including temporal bone CT. (author)

  5. Clinical significance of temporal bone CT with regard to hearing preservation in acoustic neurinoma removal

    Energy Technology Data Exchange (ETDEWEB)

    Umezu, Hiromichi; Seki, Yojirou; Aiba, Tadashi

    1988-02-01

    Since Rand and Kurze discussed the possibility of the anatomic preservation of the cochlear nerve via the posterior fossa transmeatal approach for the acoustic neurinoma, there have been increasingly many reports on the preservation of cochlear nerve function. With recent advances in diagnostic tools, today's neurosurgeon is able to make an earlier and more precise diagnosis of acoustic neurinomas even when the patient has good hearing. If useful hearing is to be kept, the cochlear nerve and blood supply of the labyrinth have to be preserved. In addition, surgical entry into the labyrinth, upon the removal of the posterior wall of the internal auditory canal, must be avoided, since it is likely to result in permanent hearing loss. Because of its superior contrast and spatial resolution, thin-section and high-resolution computed tomography of the temporal bone has the great advantage of demonstrating the exact relationship of the internal auditory canal to the posterior semicircular canal, the vestibule, and the common crus. In this study, thin-section, high-resolution computed tomography of the temporal bone was performed in 11 cases of acoustic neurinoma pre- and postoperatively. At operation, the lateral limit of the bone removal of the posterior internal auditory canal was determined on the basis of preoperative computed tomography of the temporal bone. As a result, inadvertent entry into the labyrinth was avoided, and useful hearing was preserved in 8 cases. In order to preserve useful hearing following total tumor removal, it is essential to plan the operative strategy meticulously on the basis of the findings of the preoperative investigation, Including temporal bone CT.

  6. CT and MRI characteristica of tumours of the temporal bone and the cerebello-pontine angle

    International Nuclear Information System (INIS)

    Imhof, H.; Henk, C.B.; Dirisamer, A.; Czerny, C.; Gstoettner, W.

    2003-01-01

    Tumours lesions of the temporal bone and of the cerebello-pontine angle are rare.This tumours can be separated into benign and malignant lesions. In this paper the CT and MRI characteristica of tumours of the temporal bone and the cerebello-pontane angle will be demonstrated. High resolution CT (HRCT) as usually performed in the axial plane are using a high resolution bone window level setting, coronal planes are the reconstructed from the axial data set or will be obtained directly. With the MRI FLAIR sequence in the axial plane the whole brain will be scanned either to depict or exclude a tumour invasion into the brain. After this,T2-weighted fast spin echo sequences or fatsuppressed inversion recovery sequences in high resolution technique in the axial plane will be obtained from the temporal bone and axial T1-weighted spinecho sequences before and after the intravenous application of contrast material will be obtained of this region. Finally T1-weighted spinecho sequences in high resolution technique with fatsuppression after the intravenous application of contrast material will be performed in the coronal plane. HRCT and MRI are both used to depict the most exact tumorous borders. HRCT excellently depicts the osseous changes for example exostosis of the external auditory canal, while also with HRCT osseous changes maybe characterized into more benign or malignant types. MRI has a very high soft tissue contrast and may therefore either characterize vascular space-occupying lesions for example glomus jugulare tumours or may differentiate between more benign or malignant lesions. In conclusion HRCT and MRI of the temporal bone are excellent methods to depict and mostly characterize tumour lesions and can help to differentiate between benign and malignant lesion. These imaging methods shall be used complementary and may have a great impact for the therapeutic planning. (orig.) [de

  7. Fracture of the temporal bone in patients with traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Secchi, Myrian Marajó Dal

    2012-01-01

    Full Text Available Introduction: The fractures in the temporal bone are lesions that are observed in patients with traumatic brain injury (TBI. The computed tomography of high-resolution (CT allows evaluating the fracture and the complications. Objective: Evaluate patients with TBI and temporal bone fracture. Way of study: Retrospective study. Method: Were evaluated 28 patients interned by TBI with clinical evidence and/or radiologic from temporal bone fractures. Results: The age ranged from 3 to 75 years. The most affected side was the right side 50% (n=14, left side 36% (n=10 and both sides 14% (n=4. The etiology of the trauma was the falling 25% (n=7, accidents with motorcycles and bicycles 21% (n=6, physical aggression 14% (n=4, running over 11% (n=3, fall of object 4% (n=1 and other causes 25% (n=7. The clinical signs were: Otorrhagia 78%, otalgia 11% (n=3, otorrhea 7% (n=2, facial paralysis 7% (n=2 and hearing loss 7% (n=2. The otoscopic findings: otorrhagia 57% (n=16, laceration of external auditory canal 36% (n=10, hemotympanum 11% (n=3, normal 7% (n=2 and Battle signal 7% (n=2. The findings for CT of skull were: with no alterations 54% (n=15 and temporal fracture 7% (n=2 and the CT of temporal bones were: line of fracture 71% (n=20, opacification of the mastoid 25% (n=7, glenoid cavity air 14% (n=1, dislocation of the ossicular chain 7% (n=2 and veiling of the middle ear 4% (n=1. Conclusion: Patients with TBI must be submitted to the otorhinolaryngological evaluation and imaging, for the early diagnosis of the complications and treatment.

  8. CT-MR image data fusion for computer assisted navigated neurosurgery of temporal bone tumors

    International Nuclear Information System (INIS)

    Nemec, Stefan Franz; Donat, Markus Alexander; Mehrain, Sheida; Friedrich, Klaus; Krestan, Christian; Matula, Christian; Imhof, Herwig; Czerny, Christian

    2007-01-01

    Purpose: To demonstrate the value of multi detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative work up of temporal bone tumors and to present, especially, CT and MR image fusion for surgical planning and performance in computer assisted navigated neurosurgery of temporal bone tumors. Materials and methods: Fifteen patients with temporal bone tumors underwent MDCT and MRI. MDCT was performed in high-resolution bone window level setting in axial plane. The reconstructed MDCT slice thickness was 0.8 mm. MRI was performed in axial and coronal plane with T2-weighted fast spin-echo (FSE) sequences, un-enhanced and contrast-enhanced T1-weighted spin-echo (SE) sequences, and coronal T1-weighted SE sequences with fat suppression and with 3D T1-weighted gradient-echo (GE) contrast-enhanced sequences in axial plane. The 3D T1-weighted GE sequence had a slice thickness of 1 mm. Image data sets of CT and 3D T1-weighted GE sequences were merged utilizing a workstation to create CT-MR fusion images. MDCT and MR images were separately used to depict and characterize lesions. The fusion images were utilized for interventional planning and intraoperative image guidance. The intraoperative accuracy of the navigation unit was measured, defined as the deviation between the same landmark in the navigation image and the patient. Results: Tumorous lesions of bone and soft tissue were well delineated and characterized by CT and MR images. The images played a crucial role in the differentiation of benign and malignant pathologies, which consisted of 13 benign and 2 malignant tumors. The CT-MR fusion images supported the surgeon in preoperative planning and improved surgical performance. The mean intraoperative accuracy of the navigation system was 1.25 mm. Conclusion: CT and MRI are essential in the preoperative work up of temporal bone tumors. CT-MR image data fusion presents an accurate tool for planning the correct surgical procedure and is a

  9. Semicircular canal dehiscence: Frequency and distribution on temporal bone CT and its relationship with the clinical outcomes

    International Nuclear Information System (INIS)

    Elmali, Muzaffer; Polat, Ahmet Veysel; Kucuk, Harun; Atmaca, Sinan; Aksoy, Ahmet

    2013-01-01

    Purpose: In this study, we aimed to investigate the frequency of SCD and its distribution and relationship with clinical outcomes on thin-section CT of the temporal bone. Materials and methods: Digital temporal bone CT images of 850 consecutive patients (1700 temporal bone CTs, 5100 SCs) who presented with a range of complaints such as vertigo, deafness, ear pain, fullness, and discharge between January 2008 and December 2011 were re-evaluated. Axial and oblique coronal reconstruction images of the temporal bone were made with a reconstruction thickness of 0.5 mm. Additionally, superior SC was evaluated in two perpendicular planes. Results: Out of 850 patients, 70 had completely normal temporal bone CT. Ninety-three patients had at least one SCD. In the temporal bone-based evaluation, 119 (26 bilateral, 67 unilateral) of 1700 temporal bones (7%) showed dehiscence. The SC-based evaluation revealed 125 SCD (2.5%) in 5100 SCs. The total number and rates of SCD were as follows: superior 103 (82.4%), posterior 13 (10.4%), and lateral nine (7.2%). Twenty of the 93 patients with SCD (21.5%) revealed no other findings on their temporal bone CTs. We determined a significant correlation between vestibular complaints, conductive hearing loss and SCD but there was no correlation between mixed, sensorineural hearing loss and SCD. Conclusion: We determined the frequency of SCD in 11% of patients and 7% of temporal bones. With regards to the distribution, the superior SC showed the highest dehiscence rate (82.4%). We found a significant correlation between vestibular symptoms, conductive hearing loss and SCD

  10. Semicircular canal dehiscence: Frequency and distribution on temporal bone CT and its relationship with the clinical outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Elmali, Muzaffer, E-mail: muzafel@yahoo.com.tr [Department of Radiology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Polat, Ahmet Veysel, E-mail: veyselp@hotmail.com [Department of Radiology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Kucuk, Harun, E-mail: hardrmd@yahoo.com [Department of Otorhinolaryngology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Atmaca, Sinan, E-mail: sinanatmaca@yahoo.com [Department of Otorhinolaryngology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey); Aksoy, Ahmet, E-mail: toxocara47@hotmail.com [Department of Otorhinolaryngology, Ondokuz Mayis University, Faculty of Medicine, Samsun (Turkey)

    2013-10-01

    Purpose: In this study, we aimed to investigate the frequency of SCD and its distribution and relationship with clinical outcomes on thin-section CT of the temporal bone. Materials and methods: Digital temporal bone CT images of 850 consecutive patients (1700 temporal bone CTs, 5100 SCs) who presented with a range of complaints such as vertigo, deafness, ear pain, fullness, and discharge between January 2008 and December 2011 were re-evaluated. Axial and oblique coronal reconstruction images of the temporal bone were made with a reconstruction thickness of 0.5 mm. Additionally, superior SC was evaluated in two perpendicular planes. Results: Out of 850 patients, 70 had completely normal temporal bone CT. Ninety-three patients had at least one SCD. In the temporal bone-based evaluation, 119 (26 bilateral, 67 unilateral) of 1700 temporal bones (7%) showed dehiscence. The SC-based evaluation revealed 125 SCD (2.5%) in 5100 SCs. The total number and rates of SCD were as follows: superior 103 (82.4%), posterior 13 (10.4%), and lateral nine (7.2%). Twenty of the 93 patients with SCD (21.5%) revealed no other findings on their temporal bone CTs. We determined a significant correlation between vestibular complaints, conductive hearing loss and SCD but there was no correlation between mixed, sensorineural hearing loss and SCD. Conclusion: We determined the frequency of SCD in 11% of patients and 7% of temporal bones. With regards to the distribution, the superior SC showed the highest dehiscence rate (82.4%). We found a significant correlation between vestibular symptoms, conductive hearing loss and SCD.

  11. Pneumatic conveying design guide

    CERN Document Server

    Mills, David

    1990-01-01

    Pneumatic Conveying Design Guide is a guide for the design of pneumatic conveying systems and includes detailed data and information on the conveying characteristics of a number of materials with a wide range of properties. This book includes logic diagrams for design procedures and scaling parameters for the conveying line configuration. It also explains how to improve the performance of pneumatic conveyors by optimizing, uprating, and extending the system or adapting it for a change of material. This book consists of 15 chapters divided into three sections and opens with an overview of the s

  12. Aspects of temporal bone anatomy and pathology in conjunction with cochlear implant surgery

    Energy Technology Data Exchange (ETDEWEB)

    Stjernholm, Christina [Karolinska Inst., Stockholm (Sweden). Soedersjukhuset

    2003-07-01

    Cochlear implantation is a treatment for patients with severe sensorineural hearing loss/deafness, who get no help from ordinary hearing aids. The cochlear implant is surgically placed under the skin near the ear and a very thin electrode array is introduced into the cochlea of the inner ear, where it stimulates the remaining nerve fibers. The operation is complicated; it is performed with the aid of a microscope, and involves drilling very close to vital vessels and important nerves. High resolution computed tomography (CT) of the temporal bone is a part of the preoperative evaluation preceding cochlear implantation. It is a method for visualizing the bony structures of the middle and inner ear - to diagnose pathology and to describe the anatomy. The first work concerns CT of the temporal bone and cochlear implant surgery in children with CHARGE association. This is a rare condition with multiple congenital abnormalities, sometimes lethal. Children with CHARGE have different combinations of disabilities, of which impairments of vision and hearing, as well as balance problems and facial palsy can lead to developmental delay. There have been few reports of radiological temporal bone changes and none of cochlear implant surgery for this group. The work includes a report of the findings on preoperative CT and at surgery, as well as postimplant results in two children. A review of the latest diagnostic criteria of CHARGE and the temporal bone changes found in international literature is also included. The conclusion was that certain combinations of temporal bone changes in CHARGE are, if not specific, at least extremely rare in other materials. CT can visualize these changes and be used as a diagnostic tool. This is important, since some of the associated disabilities are not so obvious from the start. Early treatment is vital for the child's development. This work also shows that cochlear implantation may help some of these often very isolated children to

  13. Aspects of temporal bone anatomy and pathology in conjunction with cochlear implant surgery

    International Nuclear Information System (INIS)

    Stjernholm, Christina

    2003-01-01

    Cochlear implantation is a treatment for patients with severe sensorineural hearing loss/deafness, who get no help from ordinary hearing aids. The cochlear implant is surgically placed under the skin near the ear and a very thin electrode array is introduced into the cochlea of the inner ear, where it stimulates the remaining nerve fibers. The operation is complicated; it is performed with the aid of a microscope, and involves drilling very close to vital vessels and important nerves. High resolution computed tomography (CT) of the temporal bone is a part of the preoperative evaluation preceding cochlear implantation. It is a method for visualizing the bony structures of the middle and inner ear - to diagnose pathology and to describe the anatomy. The first work concerns CT of the temporal bone and cochlear implant surgery in children with CHARGE association. This is a rare condition with multiple congenital abnormalities, sometimes lethal. Children with CHARGE have different combinations of disabilities, of which impairments of vision and hearing, as well as balance problems and facial palsy can lead to developmental delay. There have been few reports of radiological temporal bone changes and none of cochlear implant surgery for this group. The work includes a report of the findings on preoperative CT and at surgery, as well as postimplant results in two children. A review of the latest diagnostic criteria of CHARGE and the temporal bone changes found in international literature is also included. The conclusion was that certain combinations of temporal bone changes in CHARGE are, if not specific, at least extremely rare in other materials. CT can visualize these changes and be used as a diagnostic tool. This is important, since some of the associated disabilities are not so obvious from the start. Early treatment is vital for the child's development. This work also shows that cochlear implantation may help some of these often very isolated children to communicate

  14. Neutrophil Extracellular Traps and Fibrin in Otitis Media: Analysis of Human and Chinchilla Temporal Bones.

    Science.gov (United States)

    Schachern, Patricia A; Kwon, Geeyoun; Briles, David E; Ferrieri, Patricia; Juhn, Steven; Cureoglu, Sebahattin; Paparella, Michael M; Tsuprun, Vladimir

    2017-10-01

    Bacterial resistance in acute otitis can result in bacterial persistence and biofilm formation, triggering chronic and recurrent infections. To investigate the middle ear inflammatory response to bacterial infection in human and chinchilla temporal bones. Six chinchillas underwent intrabullar inoculations with 0.5 mL of 106 colony-forming units (CFUs) of Streptococcus pneumoniae, serotype 2. Two days later, we counted bacteria in middle ear effusions postmortem. One ear from each chinchilla was processed in paraffin and sectioned at 5 µm. The opposite ear was embedded in epoxy resin, sectioned at a thickness of 1 µm, and stained with toluidine blue. In addition, we examined human temporal bones from 2 deceased donors with clinical histories of otitis media (1 with acute onset otitis media, 1 with recurrent infection). Temporal bones had been previously removed at autopsy, processed, embedded in celloidin, and cut at a thickness of 20 µm. Sections of temporal bones from both chinchillas and humans were stained with hematoxylin-eosin and immunolabeled with antifibrin and antihistone H4 antibodies. Histopatological and imminohistochemical changes owing to otitis media. Bacterial counts in chinchilla middle ear effusions 2 days after inoculation were approximately 2 logs above initial inoculum counts. Both human and chinchilla middle ear effusions contained bacteria embedded in a fibrous matrix. Some fibers in the matrix showed positive staining with antifibrin antibody, others with antihistone H4 antibody. In acute and recurrent otitis media, fibrin and neutrophil extracellular traps (NETs) are part of the host inflammatory response to bacterial infection. In the early stages of otitis media the host defense system uses fibrin to entrap bacteria, and NETs function to eliminate bacteria. In chronic otitis media, fibrin and NETs appear to persist.

  15. Diagnosis of temporal bone diseases using three-dimensional images with multislice CT

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Yoshihiro; Togami, Taro; Murota, Makiko; Fukunaga, Kotaro; Hino, Ichiro; Sato, Katashi; Ohkawa, Motoomi [Kagawa Medical Univ., Miki (Japan)

    2001-08-01

    We evaluated the usefulness of three-dimensional images with multislice CT in the temporal bone diseases. Fifty-nine cases (26 with medial otitis, 8 choresteatoma, 10 congenital malformation, 3 high jugular bulb, 2 otosclerosis, and 10 others) were included in this study. In the ossicular and inner ear lesions, oblique multiplanar images of the long axis of each ossicle was useful the detection of abnormality. Structural deformity of ossicles and bony labyrinth were clearly delineated by surface rendering images. (author)

  16. Does microtia predict severity of temporal bone CT abnormalities in children with persistent conductive hearing loss?

    Science.gov (United States)

    Tekes, Aylin; Ishman, Stacey L; Baugher, Katherine M; Brown, David J; Lin, Sandra Y; Tunkel, David E; Unalp-Arida, Aynur; Huisman, Thierry A G M

    2013-07-01

    This study aimed to determine the spectrum of temporal bone computed tomography (CT) abnormalities in children with conductive hearing loss (CHL) with and without microtia. From 1993 to 2008, a total of 3396 pediatric records including CHL were reviewed at our institution and revealed 180 cases of persistent CHL, 46 of whom had diagnostic temporal bone CT examinations. All of these examinations were systematically reviewed by two pediatric neuroradiologists, working in consensus, who had 5 and 18 years, respectively, of dedicated pediatric neuroradiology experience. Of the 46 children, 16 were boys and 30 were girls (age: 0.2-16 years; mean: 5 years). Also, 21 (46%) children had microtia and 25 (54%) children did not, as determined by clinical evaluation. External auditory canal atresia/stenosis (EAC-A/S) was the most common anomaly in both microtia and non-microtia groups. Two or more anomalies were observed in 18/21 children with microtia. The frequency of EAC-A/S was greater in children with microtia versus those without it (86% versus 32%, respectively; P = 0.0003). Syndromic diagnoses were also significantly more frequently made in children with microtia versus those without microtia (76% versus 20%, respectively; P = 0.0001). Temporal bone CT scans were normal in 10 children (22%) with persistent CHL. Microtia is an important finding in children with CHL. EAC and middle ear/ossicle anomalies were significantly more frequently seen in children with microtia, and multiple anomalies and bilateral microtia were more common in children with syndromic associations. These findings highlight the importance of understanding the embryological development of the temporal bone. The presence of one anomaly should raise suspicion of the possibility of other anomalies, especially in the setting of microtia. Bilateral microtia and multiple anomalies should also raise suspicion of genetic syndromes. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  17. Visualization of subtle temporal bone structures. Comparison of cone beam CT and MDCT

    International Nuclear Information System (INIS)

    Pein, M.K.; Plontke, S.K.; Brandt, S.; Koesling, S.

    2014-01-01

    The purpose of this study was to compare the visualization of subtle, non-pathological temporal bone structures on cone beam computed tomography (CBCT) and multi-detector computed tomography (MDCT) in vivo. Temporal bone studies of images from 38 patients archived in the picture archiving and communication system (PACS) were analyzed (slice thickness MDCT 0.6 mm and CBCT 0.125 mm) of which 23 were imaged by MDCT and 15 by CBCT using optimized standard protocols. Inclusion criteria were normal radiological findings, absence of previous surgery and anatomical variants. Images were evaluated blind by three trained observers. Using a five-point scale the visualization of ten subtle structures of the temporal bone was analyzed. Subtle middle ear structures showed a tendency to be more easily distinguishable by CBCT with significantly better visualization of the tendon of the stapedius muscle and the crura of the stapes on CBCT (p = 0.003 and p = 0.033, respectively). In contrast, inner ear components, such as the osseus spiral lamina and the modiolus tended to be better detectable on MDCT, showing significant differences for the osseous spiral lamina (p = 0.001). The interrater reliability was 0.73 (Cohen's kappa coefficient) and intraobserver reliability was 0.89. The use of CBCT and MDCT allows equivalent and excellent imaging results if optimized protocols are chosen. With both imaging techniques subtle temporal bone structures could be visualized with a similar degree of definition. In vivo differences do not seem to be as large as suggested in several previous studies. (orig.) [de

  18. CT diagnosis and differential diagnosis of otodystrophic lesions of the temporal bone

    Energy Technology Data Exchange (ETDEWEB)

    D' Archambeau, O.; Parizel, P.M.; Schepper, A.M. De (Antwerp University Hospital (Belgium). Department of Radiology); Koekelkoren, E.; Van De Heyning, P. (Antwerp University Hospital (Belgium). Department of E.N.T.)

    The purpose of this study was to assess the diagnostic and differential diagnostic value of high-resolution computed tomography in the evaluation of temporal-bone dystrophies. The study group included 55 patients with osseous abnormalities of the temporal bone in general, and the labyrinthine capsule in particular. In 27 patients the CT scan revealed evidence of otodystrophic lesions. The CT findings in patients with otosclerosis (21 patients), osteogenesis imperfecta (two patients), fibrous dysplasia (one patient). Paget's disease (one patient) and osteoporosis (two patients) are described. The CT scans of 17 patients revealed secondary osseous lesions due to metastasis (five patients), post-inflammatory changes (10 patients) or labyrinthitis ossificans (two patients). Normal variants and congenital mineralization defects were diagnosed in nine patients, Down's syndrome in two. Our results indicate the importance of high-resolution computed tomography as the primary imaging modality in evaluating osseous lesions of the temporal bone and labyrinth. (author). 14 refs.; 13 figs; 2 tabs.

  19. Inflammation and tumors of the temporal bone; Entzuendungen und Tumoren des Schlaefenbeins

    Energy Technology Data Exchange (ETDEWEB)

    Burian, M. [Universitaetsklinik fuer Hals-, Nasen- und Ohrenkrankheiten, Allgemeines Krankenhaus, Wien (Austria)

    1997-12-01

    The term `inflammation of the middle ear` covers a couple of deseases which range from the acute otitis media to the middle ear cholesteatoma. However, a clear characterization of a certain pathology is essential for any further treatment. Therefore this article presents a short overview about the different types of infections and their clinical manifestation. The tumors of the temporal bone show a great variety in their incidence. Even if tumors like the acoustic neurinoma or the paraganglioma are compareable common, the chondroblastoma of the temporal bone is absolutely rare. In spite of these differences the individual temporal bone neoplasias are shortly mentioned herein. (orig.) [Deutsch] Der Begriff Mittelohrentzuendung umfasst ein weites Spektrum von Krankheiten welches von der akuten Mittelohrentzuendung bis hin zum Cholesteatom reicht. Es soll in diesem Artikel eine kurze Uebersicht ueber die verschiedenen Entzuendungen gegeben werden, wobei vor allem auf eine klare Begriffsdefinition der einzelnen Entzuendungsformen und deren klinisches Erscheinungsbild geachtet wurde. Bei den Tumoren des Schlaefenbeins ist ein grosser Unterschied in der Inzidenz der einzelnen Tumoren gegeben. Waehrend Neubildungen wie das Akustikusneurinom oder das Paragangliom vergleichsweise haeufig im klinischen Alltag zu sehen sind, stellen Veraenderungen wie das Chondroblastom eine Raritaet dar. Trotz dieses Unterschieds im Vorkommen der verschiedenen Tumoren, wurde versucht, einen kurzen Gesamtueberblick ueber die Tumore des Mittel- und Innenohres zu geben. (orig.)

  20. Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics

    Science.gov (United States)

    Lockwood, Charles A; Lynch, John M; Kimbel, William H

    2002-01-01

    The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade. PMID:12489757

  1. Bilateral Non-Hodgkin’s Lymphoma of the Temporal Bone: A Rare and Unusual Presentation

    Directory of Open Access Journals (Sweden)

    Sanjay Vaid

    2016-01-01

    Full Text Available Primary lymphoma of the temporal bone is an unusual finding in clinical practice and bilateral affection is even more rare. To the best of our knowledge, there are no reports of bilateral primary temporal bone lymphoma without middle ear involvement in the English medical literature so far. We report, for the first time, a case of primary lymphoma involving both temporal bones which presented with left-sided infranuclear facial palsy. A combination of contrast enhanced magnetic resonance imaging (MRI and high resolution computed tomography (HRCT was used to characterize and to map the extent of the lesion, as well as to identify the exact site of facial nerve affection. An excision biopsy and immunohistochemistry revealed diffuse large B-cell non-Hodgkin’s lymphoma (DLBCL. Whole body fluorodeoxyglucose (FDG positron emission tomography-computed tomography study (PET-CT was performed to stage the disease. The patient was treated with chemotherapy and radiation therapy and is now on regular follow-up. The patient is alive and asymptomatic without disease progression for the last twenty months after initial diagnosis.

  2. Morphometrical Study of the Temporal Bone and Auditory Ossicles in Guinea Pig

    Directory of Open Access Journals (Sweden)

    Ahmadali Mohammadpour

    2011-03-01

    Full Text Available In this research, anatomical descriptions of the structure of the temporal bone and auditory ossicles have been performed based on dissection of ten guinea pigs. The results showed that, in guinea pig temporal bone was similar to other animals and had three parts; squamous, tympanic and petrous .The tympanic part was much better developed and consisted of oval shaped tympanic bulla with many recesses in tympanic cavity. The auditory ossicles of guinea pig concluded of three small bones; malleus, incus and stapes but the head of the malleus and the body of incus were fused and forming a malleoincudal complex. The average of morphometric parameters showed that the malleus was 3.53 ± 0.22 mm in total length. In addition to head and handle, the malleus had two distinct process; lateral and muscular. The incus had a total length 1.23 ± 0.02mm. It had long and short crus although the long crus was developed better than short crus. The lenticular bone was a round bone that articulated with the long crus of incus. The stapes had a total length 1.38 ± 0.04mm. The anterior crus(0.86 ± 0.08mm was larger than posterior crus (0.76 ± 0.08mm. It is concluded that, in the guinea pig, the malleus and the incus are fused, forming a junction called incus-malleus, while in the other animals these are separate bones. The stapes is larger and has a triangular shape and the anterior and posterior crus are thicker than other rodents. Therefore, for otological studies, the guinea pig is a good lab animal.

  3. Pneumatic Muscle Actuator Control

    National Research Council Canada - National Science Library

    Lilly, John

    2000-01-01

    This research is relevant to the Air Fore mission because pneumatic muscle actuation devices arc advantageous for certain types of robotics as well as for strength and/or mobility assistance for humans...

  4. Pneumatic transfer systems

    International Nuclear Information System (INIS)

    Bichler, H.; Boeck, H.; Hammer, J.; Buchtela, K.

    1988-11-01

    A pneumatic transfer system for research reactors, including a sample changer system and to be used for neutron activation analysis, is described. The system can be obtained commercially from the Atominstitut. 2 figs. (qui)

  5. Fibrous Dysplasia of the Temporal Bone with External Auditory Canal Stenosis and Secondary Cholesteatoma.

    Science.gov (United States)

    Liu, Yu-Hsi; Chang, Kuo-Ping

    2016-04-01

    Fibrous dysplasia is a slowly progressive benign fibro-osseous disease, rarely occurring in temporal bones. In these cases, most bony lesions developed from the bony part of the external auditory canals, causing otalgia, hearing impairment, otorrhea, and ear hygiene blockade and probably leading to secondary cholesteatoma. We presented the medical history of a 24-year-old woman with temporal monostotic fibrous dysplasia with secondary cholesteatoma. The initial presentation was unilateral conductive hearing loss. A hard external canal tumor contributing to canal stenosis and a near-absent tympanic membrane were found. Canaloplasty and type I tympanoplasty were performed, but the symptoms recurred after 5 years. She received canal wall down tympanomastoidectomy with ossciculoplasty at the second time, and secondary cholesteatoma in the middle ear was diagnosed. Fifteen years later, left otorrhea recurred again and transcanal endoscopic surgery was performed for middle ear clearance. Currently, revision surgeries provide a stable auditory condition, but her monostotic temporal fibrous dysplasia is still in place.

  6. Mastoid pneumatisation of the temporal bone in human in radiographic and anthropometric studies

    International Nuclear Information System (INIS)

    Czerwinski, F.; Badowicz, B.; Teul, I.; Zbiec, K.

    1993-01-01

    Correlation between the three chosen anthropometric indexes of neurocranium and the degree of mastoid pneumatization has been investigated in 100 male adult skulls. Anthropometric data of the neurocranium have been collected and the three anthropometric indexes have been counted. Radiographs of every mastoid were taken in the Schuller lateral projection. No notable correlation between the three chosen anthropometric indexes of neurocranium and the degree of mastoid pneumatization has been observed. (author)

  7. Direct radiocarbon dating and DNA analysis of the Darra-i-Kur (Afghanistan) human temporal bone.

    Science.gov (United States)

    Douka, Katerina; Slon, Viviane; Stringer, Chris; Potts, Richard; Hübner, Alexander; Meyer, Matthias; Spoor, Fred; Pääbo, Svante; Higham, Tom

    2017-06-01

    The temporal bone discovered in the 1960s from the Darra-i-Kur cave in Afghanistan is often cited as one of the very few Pleistocene human fossils from Central Asia. Here we report the first direct radiocarbon date for the specimen and the genetic analyses of DNA extracted and sequenced from two areas of the bone. The new radiocarbon determination places the find to ∼4500 cal BP (∼2500 BCE) contradicting an assumed Palaeolithic age of ∼30,000 years, as originally suggested. The DNA retrieved from the specimen originates from a male individual who carried mitochondrial DNA of the modern human type. The petrous part yielded more endogenous ancient DNA molecules than the squamous part of the same bone. Molecular dating of the Darra-i-Kur mitochondrial DNA sequence corroborates the radiocarbon date and suggests that the specimen is younger than previously thought. Taken together, the results consolidate the fact that the human bone is not associated with the Pleistocene-age deposits of Darra-i-Kur; instead it is intrusive, possibly re-deposited from upper levels dating to much later periods (Neolithic). Despite its Holocene age, the Darra-i-Kur specimen is, so far, the first and only ancient human from Afghanistan whose DNA has been sequenced. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The temporal bones from Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain). A phylogenetic approach.

    Science.gov (United States)

    Martínez, I; Arsuaga, J L

    1997-01-01

    Three well-preserved crania and 22 temporal bones were recovered from the Sima de los Huesos Middle Pleistocene site up to and including the 1994 field season. This is the largest sample of hominid temporal bones known from a single Middle Pleistocene site and it offers the chance to characterize the temporal bone morphology of an European Middle Pleistocene population and to study the phylogenetic relationships of the SH sample with other Upper and Middle Pleistocene hominids. We have carried out a cladistic analysis based on nine traits commonly used in phylogenetic analysis of Middle and Late Pleistocene hominids: shape of the temporal squama superior border, articular eminence morphology, contribution of the sphenoid bone to the median glenoid wall, postglenoid process projection, tympanic plate orientation, presence of the styloid process, mastoid process projection, digastric groove morphology and anterior mastoid tubercle. We have found two autapomorphies on the Home erectus temporal bone: strong reduction of the postglenoid process and absence of the styloid process. Modern humans, Neandertals and the Middle Pleistocene fossils from Europe and Africa constitute a clade characterized by a convex superior border of the temporal squama. The European Middle Pleistocene fossils from Sima de los Huesos, Petralona, Steinheim, Bilzingsleben and Castel di Guido share a Neandertal apomorphy: a relatively flat articular eminence. The fossils from Ehringsdorf, La Chaise Suardi and Biache-Saint-Vaast also display another Neandertal derived trait: an anteriorly obliterated digastric groove. Modern humans and the African Middle Pleistocene fossils share a synapomorphy: a sagittally orientated tympanic plate.

  9. Intraoperative cone-beam computed tomography and multi-slice computed tomography in temporal bone imaging for surgical treatment.

    Science.gov (United States)

    Erovic, Boban M; Chan, Harley H L; Daly, Michael J; Pothier, David D; Yu, Eugene; Coulson, Chris; Lai, Philip; Irish, Jonathan C

    2014-01-01

    Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens. Cross-sectional study. University tertiary care facility. Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures. CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus. CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.

  10. Three dimensional CT of stapes. Stapedial imagings in dry temporal bone and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Edamatsu, Hideo; Kubota, Osamu; Yamashita, Koichi [Kanazawa Medical Univ., Ishikawa (Japan)

    1995-03-01

    This study was performed to evaluate the usefulness and limitations of three dimensional (3-D) imagings of stapes in the middle ear by high speed helical CT. One dissected human temporal bone, ten normal and diseased ears were scanned with a slice of 1.0 mm and reconstructed in a thickness of 0.2-0.5 mm. Every specimen of 3-D can be observed in any plane and from any direction. Ossicular imagings of the temporal bone in 3-D were reconstructed as if the malleus, incus and stapes were observed under microscope. The whole structure of stapes was impossible to be represented by two dimensional CT heretofore in use, but 3-D in our study showed the head, crus and foot plate of the stapes in detail. Stapedial imagings of 3-D CT in normal ears showed the same findings as those recorded in temporal bone. Preoperative diagnostic findings of ossicles in the affected ears were very useful. Especially in ossicular anomalies, 3-D CT was positive in diagnosis and its accuracies were confirmed with operative observation. For the postoperative evaluation concerning the ossicular reconstruction, i.e. TORP and PORP, 3-D CT was also important method. It could present an anatomical relation between those prosthesis and the oval window. High speed helical CT can scan an object more quickly and clearly than formerly used CT, and its biological damage for human is less than that of the others. 3-D CT can be more clearly reconstructed with helical CT than former CT. (author).

  11. Accuracy of linear drilling in temporal bone using drill press system for minimally invasive cochlear implantation.

    Science.gov (United States)

    Dillon, Neal P; Balachandran, Ramya; Labadie, Robert F

    2016-03-01

    A minimally invasive approach for cochlear implantation involves drilling a narrow linear path through the temporal bone from the skull surface directly to the cochlea for insertion of the electrode array without the need for an invasive mastoidectomy. Potential drill positioning errors must be accounted for to predict the effectiveness and safety of the procedure. The drilling accuracy of a system used for this procedure was evaluated in bone surrogate material under a range of clinically relevant parameters. Additional experiments were performed to isolate the error at various points along the path to better understand why deflections occur. An experimental setup to precisely position the drill press over a target was used. Custom bone surrogate test blocks were manufactured to resemble the mastoid region of the temporal bone. The drilling error was measured by creating divots in plastic sheets before and after drilling and using a microscope to localize the divots. The drilling error was within the tolerance needed to avoid vital structures and ensure accurate placement of the electrode; however, some parameter sets yielded errors that may impact the effectiveness of the procedure when combined with other error sources. The error increases when the lateral stage of the path terminates in an air cell and when the guide bushings are positioned further from the skull surface. At contact points due to air cells along the trajectory, higher errors were found for impact angles of [Formula: see text] and higher as well as longer cantilevered drill lengths. The results of these experiments can be used to define more accurate and safe drill trajectories for this minimally invasive surgical procedure.

  12. Mucous retention cyst of temporal bone: a mimic of cholesteatoma on DW-MRI.

    Science.gov (United States)

    Karandikar, Amit; Goh, Julian; Loke, Siu Cheng; Yeo, Seng Beng; Tan, Tiong Yong

    2013-01-01

    Non-EPI DW imaging is increasingly being used as a sensitive sequence in detecting cholesteatomas especially if CT findings are not confirmatory. Cholesteatoma appears as a hyperintense focus on DWI. We present two cases of mucous retention cysts in the mastoid temporal bone/middle ear cavity, which present as hyperintense on non-EPI DWI and potentially may mimic cholesteatomas. Differentiating between the two conditions is important, as surgery can be avoided in mucous retention cysts. We have also discussed ways to differentiate between these two conditions on MRI. To our knowledge, this entity is not reported previously. © 2013 Elsevier Inc. All rights reserved.

  13. Destructive, granulating lesion in the temporal bone after elevated plasma homocysteine

    DEFF Research Database (Denmark)

    Bonding, Per; Skriver, Elisabeth; Helin, Pekka

    2004-01-01

    lesion in the left temporal bone was discovered; repeated histologic examination only showed simple granulation tissue. After 6 months, a part of the bony cochlea was extruded. With approximately 8 months' delay and after the patient had had postoperative lung embolism, plasma homocysteine was found...... to be significantly elevated, a condition known as an independent risk factor for thromboembolic lesions. In the acquired form, it is most often caused by nutritional deficiency of vitamin B cofactors. Accordingly, the patient was treated with folic acid, which rapidly normalized plasma homocysteine. Subsequently...

  14. Bilateral cochlear implantation in a patient with bilateral temporal bone fractures.

    Science.gov (United States)

    Chung, Jae Ho; Shin, Myung Chul; Min, Hyun Jung; Park, Chul Won; Lee, Seung Hwan

    2011-01-01

    With the emphasis on bilateral hearing nowadays, bilateral cochlear implantation has been tried out for bilateral aural rehabilitation. Bilateral sensorineural hearing loss caused by head trauma can get help from cochlear implantation. We present the case of a 44-year-old man with bilateral otic capsule violating temporal bone fractures due to head trauma. The patient demonstrated much improved audiometric and psychoacoustic performance after bilateral cochlear implantation. We believe bilateral cochlear implantation in such patient can be a very effective tool for rehabilitation. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Modifications to a 3D-printed temporal bone model for augmented stapes fixation surgery teaching.

    Science.gov (United States)

    Nguyen, Yann; Mamelle, Elisabeth; De Seta, Daniele; Sterkers, Olivier; Bernardeschi, Daniele; Torres, Renato

    2017-07-01

    Functional outcomes and complications in otosclerosis surgery are governed by the surgeon's experience. Thus, teaching the procedure to residents to guide them through the learning process as quickly as possible is challenging. Artificial 3D-printed temporal bones are replacing cadaver specimens in many institutions to learn mastoidectomy, but these are not suitable for middle ear surgery training. The goal of this work was to adapt such an artificial temporal bone to aid the teaching of otosclerosis surgery and to evaluate this tool. We have modified a commercially available 3D-printed temporal bone by replacing the incus and stapes of the model with in-house 3D-printed ossicles. The incus could be attached to a 6-axis force sensor. The stapes footplate was fenestrated and attached to a 1-axis force sensor. Six junior surgeons (residents) and seven senior surgeons (fellows or consultants) were enrolled to perform piston prosthesis placement and crimping as performed during otosclerosis surgery. The time required to perform the tasks and the forces applied to the incus and stapes were collected and analyzed. No statistically significant differences were observed between the junior and senior groups for time taken to perform the tasks and the forces applied to the incus during crimping and placement of the prosthesis. However, significantly lower forces were applied to the stapes by the senior surgeons in comparison with the junior surgeons during prosthesis placement (junior vs senior group, 328 ± 202.9 vs 80 ± 99.6 mN, p = 0.008) and during prosthesis crimping (junior vs senior group, 565 ± 233 vs 66 ± 48.6 mN, p = 0.02). We have described a new teaching tool for otosclerosis surgery based on the modification of a 3D-printed temporal bone to implement force sensors on the incus and stapes. This tool could be used as a training tool to help the residents to self-evaluate their progress with recording of objective measurements.

  16. Petrified ears in a patient with Keutel syndrome: temporal bone CT findings

    International Nuclear Information System (INIS)

    Parmar, Hemant; Blaser, Susan; Yoo, Shi-Joon; Unger, Sheila; Papsin, Blake

    2006-01-01

    We present unusual imaging findings of petrified ears in a 9-year-old girl with Keutel syndrome. The patient presented for a temporal bone study for hearing loss. CT scan showed middle and inner ear abnormalities along with extensive and unsuspected calcification of the external ears and ossicular ligaments. On further investigation, the patient was found to have diffuse cartilage calcification in the larynx and tracheobronchial tree, brachytelephalangism and peripheral pulmonary stenosis suggestive of Keutel syndrome. Confirmation was obtained by mutation analysis. (orig.)

  17. Primary chondroid chordoma arising from the petrous temporal bone: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Uk; Youn, Eun Kyung [Koryo General Hospital, Seoul (Korea, Republic of)

    1991-01-15

    Chordomas are uncommon tumors which arise from remnants of the primitive notochord. They are situated chiefly in the anterior spinal axis with a predilection for the sacrococcygeal region and the basiocciput. About 50% of chordomas are sacrococcygeal, 35% are intracranial, and 15% arise from a vertebral body. As a histologic variant of chordoma, /chondroid chordoma' was first described by Heffelfinger et al. We present a rare case of primary chondroid chordoma arising from the petrous temporal bone. To our knowledge, only two other cases of this type have been reported earlier.

  18. Primary chondroid chordoma arising from the petrous temporal bone: a case report

    International Nuclear Information System (INIS)

    Lee, Young Uk; Youn, Eun Kyung

    1991-01-01

    Chordomas are uncommon tumors which arise from remnants of the primitive notochord. They are situated chiefly in the anterior spinal axis with a predilection for the sacrococcygeal region and the basiocciput. About 50% of chordomas are sacrococcygeal, 35% are intracranial, and 15% arise from a vertebral body. As a histologic variant of chordoma, /chondroid chordoma' was first described by Heffelfinger et al. We present a rare case of primary chondroid chordoma arising from the petrous temporal bone. To our knowledge, only two other cases of this type have been reported earlier

  19. Comparison of cadaveric and isomorphic three-dimensional printed models in temporal bone education.

    Science.gov (United States)

    Hochman, Jordan B; Rhodes, Charlotte; Wong, Dana; Kraut, Jay; Pisa, Justyn; Unger, Bertram

    2015-10-01

    Current three-dimensional (3D) printed simulations are complicated by insufficient void spaces and inconsistent density. We describe a novel simulation with focus on internal anatomic fidelity and evaluate against template/identical cadaveric education. Research ethics board-approved prospective cohort study. Generation of a 3D printed temporal bone was performed using a proprietary algorithm that deconstructs the digital model into slices prior to printing. This supplemental process facilitates removal of residual material from air-containing spaces and permits requisite infiltrative access to the all regions of the model. Ten otolaryngology trainees dissected a cadaveric temporal bone (CTB) followed by a matched/isomorphic 3D printed bone model (PBM), based on derivative micro-computed tomography data. Participants rated 1) physical characteristics, 2) specific anatomic constructs, 3) usefulness in skill development, and 4) perceived educational value. The survey instrument employed a seven-point Likert scale. Trainees felt physical characteristics of the PBM were quite similar to CTB, with highly ranked cortical (5.5 ± 1.5) and trabecular (5.2 ± 1.3) bone drill quality. The overall model was considered comparable to CTB (5.9 ± 0.74), with respectable air cell reproduction (6.1 ± 1.1). Internal constructs were rated as satisfactory (range, 4.9-6.2). The simulation was considered a beneficial training tool for all types of mastoidectomy (range, 5.9-6.6), posterior tympanotomy (6.5 ± 0.71), and skull base approaches (range, 6-6.5). Participants believed the model to be an effective training instrument (6.7 ± 0.68), which should be incorporated into the temporal bone lab (7.0 ± 0.0). The PBM was thought to improve confidence (6.7 ± 0.68) and operative performance (6.7 ± 0.48). Study participants found the PBM to be an effective platform that compared favorably to CTB. The model was considered a valuable adjunctive

  20. Pneumatic soil removal tool

    International Nuclear Information System (INIS)

    Neuhaus, J.E.

    1992-01-01

    A soil removal tool is provided for removing radioactive soil, rock and other debris from the bottom of an excavation, while permitting the operator to be located outside of a containment for that excavation. The tool includes a fixed jaw, secured to one end of an elongate pipe, which cooperates with a movable jaw pivotably mounted on the pipe. Movement of the movable jaw is controlled by a pneumatic cylinder mounted on the pipe. The actuator rod of the pneumatic cylinder is connected to a collar which is slidably mounted on the pipe and forms part of the pivotable mounting assembly for the movable jaw. Air is supplied to the pneumatic cylinder through a handle connected to the pipe, under the control of an actuator valve mounted on the handle, to provide movement of the movable jaw. 3 figs

  1. Pneumatic soil removal tool

    Science.gov (United States)

    Neuhaus, John E.

    1992-01-01

    A soil removal tool is provided for removing radioactive soil, rock and other debris from the bottom of an excavation, while permitting the operator to be located outside of a containment for that excavation. The tool includes a fixed jaw, secured to one end of an elongate pipe, which cooperates with a movable jaw pivotably mounted on the pipe. Movement of the movable jaw is controlled by a pneumatic cylinder mounted on the pipe. The actuator rod of the pneumatic cylinder is connected to a collar which is slidably mounted on the pipe and forms part of the pivotable mounting assembly for the movable jaw. Air is supplied to the pneumatic cylinder through a handle connected to the pipe, under the control of an actuator valve mounted on the handle, to provide movement of the movable jaw.

  2. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew

    2006-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  3. Differential diagnosis between chronic otitis media with and without cholesteatoma by temporal bone CT: focus on bone change and mass effect

    International Nuclear Information System (INIS)

    Jung, Cheol Kyu; Park, Dong Woo; Seong, Jin Yong; Lee, Kak Soo; Park Choong Ki; Lee, Seung Ro; Hahm, Chang Kok

    2000-01-01

    In order to determine specific differences, we compared the temporal bone CT findings of chronic otitis media (COM) with and without cholesteatoma, focusing on bone change. Between 1997 and 1998, 82 patients (84 cases) underwent temporal bone CT and were shown to have COM, with or without cholesteatoma after mastoidectomy and tympanoplasty. There were 36 cases of COM with cholesteatoma (26 patients, M:F =3D 11:15; age range, 16-61 (mean, 36,2) years), and 58 cases without chlesteatoma (56 patients, M:F =3D 25:31, age range, 15-61 (mean, 36.2) years). The findings of temporal bone CT were analysed at the point of bony changes including erosion and medial displacement of ossicles (malleus, incus, and stapes), erosion or destruction of the scutum, tegmen, facial canal, and lateral semicircular canal, and ballooning of the tympanic cavity and mastoid antrum. In addition, the soft tissue changes seen on temporal bone CT were analyzed at the site of lateral bulging of soft tissue in Prussak's space, perforation of the pars flaccida, tympanic membrane retraction, and tympanosclerosis. We retrospectively compared the findings of temporal bone CT with the surgical findings, and to assess statistical significance, the Chi-square test was used. Bone erosion or destruction was seen in 36.2% of COM cases without cholesteatoma, and in 96.2% of cases with cholesteatoma. Comparing COM with and without cholesteatoma, the erosion of ossicles including the malleus (81%, 24%), incus (88%, 14%), stapes (58%, 10%), scutum (88%, 10%), facial canal (8%, 0%), and lateral semicircular canal (8%, 0%), was more common in COM with cholesteatoma (p-value less than 0.05), with the exception of erosion of the tegmen (8%, 3%). Other bony changes including medial displacement of ossicles (27%, 3%), ballooning of tympanic cavity and mastoid antrum (96%, 16%), and the soft tissue changes including lateral bulging of soft tissue in Prussak's space (58%, 14%) and perforation of the pars flaccida (35

  4. Differential diagnosis between chronic otitis media with and without cholesteatoma by temporal bone CT: focus on bone change and mass effect

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Cheol Kyu; Park, Dong Woo; Seong, Jin Yong; Lee, Kak Soo; Park Choong Ki; Lee, Seung Ro; Hahm, Chang Kok [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2000-01-01

    In order to determine specific differences, we compared the temporal bone CT findings of chronic otitis media (COM) with and without cholesteatoma, focusing on bone change. Between 1997 and 1998, 82 patients (84 cases) underwent temporal bone CT and were shown to have COM, with or without cholesteatoma after mastoidectomy and tympanoplasty. There were 36 cases of COM with cholesteatoma (26 patients, M:F =3D 11:15; age range, 16-61 (mean, 36,2) years), and 58 cases without chlesteatoma (56 patients, M:F =3D 25:31, age range, 15-61 (mean, 36.2) years). The findings of temporal bone CT were analysed at the point of bony changes including erosion and medial displacement of ossicles (malleus, incus, and stapes), erosion or destruction of the scutum, tegmen, facial canal, and lateral semicircular canal, and ballooning of the tympanic cavity and mastoid antrum. In addition, the soft tissue changes seen on temporal bone CT were analyzed at the site of lateral bulging of soft tissue in Prussak's space, perforation of the pars flaccida, tympanic membrane retraction, and tympanosclerosis. We retrospectively compared the findings of temporal bone CT with the surgical findings, and to assess statistical significance, the Chi-square test was used. Bone erosion or destruction was seen in 36.2% of COM cases without cholesteatoma, and in 96.2% of cases with cholesteatoma. Comparing COM with and without cholesteatoma, the erosion of ossicles including the malleus (81%, 24%), incus (88%, 14%), stapes (58%, 10%), scutum (88%, 10%), facial canal (8%, 0%), and lateral semicircular canal (8%, 0%), was more common in COM with cholesteatoma (p-value less than 0.05), with the exception of erosion of the tegmen (8%, 3%). Other bony changes including medial displacement of ossicles (27%, 3%), ballooning of tympanic cavity and mastoid antrum (96%, 16%), and the soft tissue changes including lateral bulging of soft tissue in Prussak's space (58%, 14%) and perforation of the pars

  5. Three-dimensional assessment of the temporal bone and mandible deformations in patients with congenital aural atresia.

    Science.gov (United States)

    Fu, Yaoyao; Li, Chenlong; Dai, Peidong; Zhang, Tianyu

    2017-10-01

    To investigate the deformations of temporal bone and mandible combined with congenital aural atresia. A total of 158 patients with congenital aural atresia were included in the study. The raw CT data of the temporal bone was imported into MIMICS v 12 and threshold dissection, region growing and three-dimensional (3D) calculation were used to calculate 3D models. The 3D characteristics of the temporal bone and upper part of mandible were assessed. The tympanic part of the temporal bone was all undeveloped. Of all the patients included, 14 patients were found to have severe maxillofacial malformations. Among them, 2 cases have floating arch, 4 cases have interrupted arch, 5 cases have mandibular processes hypoplasia and 3 cases have interrupted arch combined with severe maxillary malformation. Ten of the 14 patients were suffered from dysplasia of the mastoid part of the temporal bone as well. Maxillofacial malformations may sometimes coexist with congenital aural atresia. Otolaryngologists should not neglect the coexisted maxillofacial malformations and give timely referral to maxillofacial surgeons. Copyright © 2017. Published by Elsevier B.V.

  6. Insertion forces and intracochlear trauma in temporal bone specimens implanted with a straight atraumatic electrode array.

    Science.gov (United States)

    Mirsalehi, Marjan; Rau, Thomas S; Harbach, Lenka; Hügl, Silke; Mohebbi, Saleh; Lenarz, Thomas; Majdani, Omid

    2017-05-01

    The aim of the study was to evaluate insertion forces during manual insertion of a straight atraumatic electrode in human temporal bones, and post-implantation histologic evaluation of the samples to determine whether violation of intracochlear structures is related to insertion forces. In order to minimize intracochlear trauma and preserve residual hearing during cochlear implantation, knowledge of the insertion forces is necessary. Ten fresh frozen human temporal bones were prepared with canal wall down mastoidectomy. All samples were mounted on a one-axis force sensor. Insertion of a 16-mm straight atraumatic electrode was performed from different angles to induce "traumatic" insertion. Histologic evaluation was performed in order to evaluate intracochlear trauma. In 4 of 10 samples, dislocation of the electrode into scala vestibuli was observed. The mean insertion force for all 10 procedures was 0.003 ± 0.005 N. Insertion forces measured around the site of dislocation to scala vestibuli in 3 of 4 samples were significantly higher than insertion forces at the same location of the cochleae measured in samples without trauma (p straight atraumatic electrode is lower than reported by other studies using longer electrodes. Based on our study, insertion forces leading to basilar membrane trauma may be lower than the previously reported direct rupture forces.

  7. Creating an Optimal 3D Printed Model for Temporal Bone Dissection Training.

    Science.gov (United States)

    Takahashi, Kuniyuki; Morita, Yuka; Ohshima, Shinsuke; Izumi, Shuji; Kubota, Yamato; Yamamoto, Yutaka; Takahashi, Sugata; Horii, Arata

    2017-07-01

    Making a 3-dimensional (3D) temporal bone model is simple using a plaster powder bed and an inkjet printer. However, it is difficult to reproduce air-containing spaces and precise middle ear structures. The objective of this study was to overcome these problems and create a temporal bone model that would be useful both as a training tool and for preoperative simulation. Drainage holes were made to remove excess materials from air-containing spaces, ossicle ligaments were manually changed to bony structures, and small and/or soft tissue structures were colored differently while designing the 3D models. The outcomes were evaluated by 3 procedures: macroscopic and endoscopic inspection of the model, comparison of computed tomography (CT) images of the model to the original CT, and assessment of tactile sensation and reproducibility by 20 surgeons performing surgery on the model. Macroscopic and endoscopic inspection, CT images, and assessment by surgeons were in agreement in terms of reproducibility of model structures. Most structures could be reproduced, but the stapes, tympanic sinus, and mastoid air cells were unsatisfactory. Perioperative tactile sensation of the model was excellent. Although this model still does not embody perfect reproducibility, it proved sufficiently practical for use in surgical training.

  8. Simplified Summative Temporal Bone Dissection Scale Demonstrates Equivalence to Existing Measures.

    Science.gov (United States)

    Pisa, Justyn; Gousseau, Michael; Mowat, Stephanie; Westerberg, Brian; Unger, Bert; Hochman, Jordan B

    2018-01-01

    Emphasis on patient safety has created the need for quality assessment of fundamental surgical skills. Existing temporal bone rating scales are laborious, subject to evaluator fatigue, and contain inconsistencies when conferring points. To address these deficiencies, a novel binary assessment tool was designed and validated against a well-established rating scale. Residents completed a mastoidectomy with posterior tympanotomy on identical 3D-printed temporal bone models. Four neurotologists evaluated each specimen using a validated scale (Welling) and a newly developed "CanadaWest" scale, with scoring repeated after a 4-week interval. Nineteen participants were clustered into junior, intermediate, and senior cohorts. An ANOVA found significant differences between performance of the junior-intermediate and junior-senior cohorts for both Welling and CanadaWest scales ( P .05). Cohen's kappa found strong intrarater reliability (0.711) with a high degree of interrater reliability of (0.858) for the CanadaWest scale, similar to scores on the Welling scale of (0.713) and (0.917), respectively. The CanadaWest scale was facile and delineated performance by experience level with strong intrarater reliability. Comparable to the validated Welling Scale, it distinguished junior from senior trainees but was challenged in differentiating intermediate and senior trainee performance.

  9. Middle cranial fossa approach to repair tegmen defects assisted by three-dimensionally printed temporal bone models.

    Science.gov (United States)

    Ahmed, Sameer; VanKoevering, Kyle K; Kline, Stephanie; Green, Glenn E; Arts, H Alexander

    2017-10-01

    To explore the perioperative utility of three-dimensionally (3D)-printed temporal bone models of patients undergoing repair of lateral skull base defects and spontaneous cerebrospinal fluid leaks with the middle cranial fossa approach. Case series. 3D-printed temporal bone models-based on patient-specific, high-resolution computed tomographic imaging-were constructed using inexpensive polymer materials. Preoperatively, the models demonstrated the extent of temporal lobe retraction necessary to visualize the proposed defects in the lateral skull base. Also preoperatively, Silastic sheeting was arranged across the modeled tegmen, marked, and cut to cover all of the proposed defect sites. The Silastic sheeting was then sterilized and subsequently served as a precise intraoperative template for a synthetic dural replacement graft. Of note, these grafts were customized without needing to retract the temporal lobe. Five patients underwent the middle cranial fossa approach assisted by 3D-printed temporal bone models to repair tegmen defects and spontaneous cerebrospinal fluid leaks. No complications were encountered. The prefabricated dural repair grafts were easily placed and fit precisely onto the middle fossa floor without any additional modifications. All defects were covered as predicted by the 3D temporal bone models. At their postoperative visits, all five patients maintained resolution of their spontaneous cerebrospinal fluid leaks. Inexpensive 3D-printed temporal bone models of tegmen defects can serve as beneficial adjuncts during lateral skull base repair. The models provide a panoramic preoperative view of all tegmen defects and allow for custom templating of dural grafts without temporal lobe retraction. 4 Laryngoscope, 127:2347-2351, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  10. Mechanical implications of pneumatic neck vertebrae in sauropod dinosaurs

    Science.gov (United States)

    Schwarz-Wings, Daniela; Meyer, Christian A.; Frey, Eberhard; Manz-Steiner, Hans-Rudolf; Schumacher, Ralf

    2010-01-01

    The pre-sacral vertebrae of most sauropod dinosaurs were surrounded by interconnected, air-filled diverticula, penetrating into the bones and creating an intricate internal cavity system within the vertebrae. Computational finite-element models of two sauropod cervical vertebrae now demonstrate the mechanical reason for vertebral pneumaticity. The analyses show that the structure of the cervical vertebrae leads to an even distribution of all occurring stress fields along the vertebrae, concentrated mainly on their external surface and the vertebral laminae. The regions between vertebral laminae and the interior part of the vertebral body including thin bony struts and septa are mostly unloaded and pneumatic structures are positioned in these regions of minimal stress. The morphology of sauropod cervical vertebrae was influenced by strongly segmented axial neck muscles, which require only small attachment areas on each vertebra, and pneumatic epithelia that are able to resorb bone that is not mechanically loaded. The interaction of these soft tissues with the bony tissue of the vertebrae produced lightweight, air-filled vertebrae in which most stresses were borne by the external cortical bone. Cervical pneumaticity was therefore an important prerequisite for neck enlargement in sauropods. Thus, we expect that vertebral pneumaticity in other parts of the body to have a similar role in enabling gigantism. PMID:19801376

  11. CT and MRI findings of temporal bone anomaly in patients with tinnitus

    International Nuclear Information System (INIS)

    Wang Bing; Xian Junfang; Wang Zhenchang; Liu Zhaohui

    2011-01-01

    Objective: To study high resolution CT (HRCT) and MRI findings of temporal hone anomaly in patients with tinnitus and identify the optimal examination method in the detection of the anomaly. Methods: The HRCT and MRI data were analyzed retrospectively in 1015 patients including 145 patients with pulsatile tinnitus (PT) and 870 patients with nonpulsatile tinnitus (NPT). The positive rates of HRCT and MRI in the identification of temporal bone anomaly were analyzed and the efficiency of various examination methods was compared in revealing the anomaly. Data were tested by Chi-square test analysis. Results: Among 1015 patients, anomaly was seen in 767 cases (75.57%). High jugular bulb was found in 414 patients, accounting for 40.79%. Sigmoid sinus anomaly was detected in 387 patients (38.13%), while otitis media was found in 148 cases (14.58%), and low middle cranial fossa in 70 cases (6.90%). The positive rate of HRCT in the detection of high jugular bulb was 54.89% (365/665), which was significantly higher than those of other methods (P 2 =56.537, P<0.01). The fast imaging employing steady-state acquisition (FIESTA) sequence was the best examination method in displaying the vessel within the internal auditory canal (42/42,100%). Conclusions: High jugular bulb and sigmoid sinus anomaly were the most frequent abnormal findings of temporal bone in patients with tinnitus. Enhanced HRCT was the choice of modality in patients with PT. Plain HRCT was recommended for NPT. FIESTA sequence was the best in the evaluation of the vessel within the internal auditory canal. (authors)

  12. Evaluation of the utility of temporal subtraction images in successive whole-body bone scans: a prospective clinical study

    International Nuclear Information System (INIS)

    Shiraishi, J.; Appelbaum, D.; Pu, Y.; Engelmann, R.; Li Qiang; Doi, K.

    2007-01-01

    We have begun a prospective clinical study for evaluating the clinical utility of temporal subtraction images in successive whole-body bone scans. The computerized temporal subtraction technique has been developed in order to highlight interval changes of abnormal lesions due to skeletal metastases, primary bone tumors, osteomyelitis, and fractures. In our initial preliminary results of the prospective study which was started on November 22, 2006 in our hospital, radiologists reported some interval changes which were not recognized in the initial standard readings, but were obvious when temporal subtraction images were viewed. The usefulness of the temporal subtraction images will be investigated in terms of its clinical utility by the prospective clinical study. (orig.)

  13. The relation between mastoid pneumatization and sigmoid sinus position in chronic otomastoiditis

    International Nuclear Information System (INIS)

    Yang, Kee Hyuk; Park, Dong Woo; Lee, Seung Ro; Joo, Kyung Bin

    2001-01-01

    If significantly influenced by chronic otomastoiditis(COM), mastoid pneumatization and the position of the sigmoid sinus affect the operative procedure and postoperative complications in middle ear surgery. We evaluated mastoid pneumatization and sigmoid sinus position, and their relationship in COM, especially its during onset. Using temporal bone CT and referring to any relevant medical records, we retrospectively analyzed 107 cases of COM and 49 cases of normal ear. The total case load comprised an adult group, aged above 16 years [100 cases of COM (M:F=46:54, mean age = 45 years), and 42 cases of normal ear, (M:F=20:22, mean age = 44 years)], and a childhood group, aged less than 16 years [7 cases of COM (M:F=4:3, mean age = 8.4 years), and 7 cases of normal ear (M:F=4:3, mean age = 7 years)]. We determined the thickness of the mastoid bone by measuring the shortest distance between the outer cortex of this bone and the deepest border of the sigmoid sinus; the depth of the sigmoid sinus; and the degree of mastoid pneumatization and sclerosis. Fifty-three patients whose medical history clearly included the onset of otomastoiditis were divided into a child-onset group and an adult-onset group, and the relationship between the onset of otomastoiditis and the thickness of the mastoid bone was compared between the two groups. The mean axial thickness of the mastoid bone was 9.672±2.745 mm in COM and 12.430±3.027 mm in normal ear. The difference was statisfically significant (ρ < 0.0001). The mean depth of the sigmoid sinus was 7.557±1.868 mm in COM and 7.591±2.315 mm in normal ear, with no statistically significant difference. In the childhood group, the mean axial thickness of the mastoid bone was 8.672±2.978 mm in COM and 11.778±3.087 mm in normal ear. This difference was statistically significant (ρ < 0.05). In the adult group, the corresponding figures were 9.742±2.731 mm in COM and 12.538±3.041 mm in normal ear, a difference which was also

  14. Decolonizing Straight Temporality Through Genre Trouble in Edwidge Danticat's The Farming of Bones

    Directory of Open Access Journals (Sweden)

    Eliana de Souza Ávila

    2014-12-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2014n67p21 Framing genre trouble (McKenzie 2006 as a decolonial methodology, this paper considers the relevance of Edwidge Danticat’s The Farming of Bones (1998 for reading migrant texts against the grain of straight temporality which sustains the coloniality of power (Lugones 2007. Scrutinizing historiographic suppression, Danticat’s migrant text interrupts the chrononormative portrayal of the Trujillo genocide of Haitian workers in the Dominican Republic as a reality pertaining to an obsolete past and to the geocultural margins alone. Read in the aftermath of the testimonio controversy, it may thus decenter the ongoing deflection of attention from Rigoberta Menchú’s impact on the geocultural structures that sanction ongoing military intervention and genocide by refocusing on historiography as a terrain of relentless decolonial contestation rather than prescriptive narrative closure.

  15. Chondrosarcoma of the temporal bone. Diagnosis and treatment of 13 cases and review of the literature

    International Nuclear Information System (INIS)

    Coltrera, M.D.; Googe, P.B.; Harrist, T.J.; Hyams, V.J.; Schiller, A.L.; Goodman, M.L.

    1986-01-01

    Chondrosarcoma of the temporal bone is a rare lesion. Clinically it has been confused with multiple sclerosis, glomus jugulare tumors, meningioma, and chordomas. The cranial nerve palsies frequently observed with the tumors are related to the anatomic locations of the tumors. Thirteen patients with this entity are presented and the eleven other cases in the literature are reviewed. Histologically the tumors are low grade and exhibit myxoid features. The myxoid features must be differentiated from chordoma and chondroid chordoma. The tumor locations preclude surgical excision and conventional radiation therapy can cause unacceptable neurologic sequelae. Proton beam therapy has been effective in short-term results and appears capable of avoiding serious neurologic side effects

  16. Temporal bone trauma: correlative study between CT findings and clinical manifestations

    International Nuclear Information System (INIS)

    Kim, Jung Hee; Kim, Hyung Jin; Kim, Jae Hyoung

    1994-01-01

    To assess how accurately computed tomography (CT) can demonstrate the abnormal findings which are believed to cause the clinical signs and symptoms of hearing loss (HL), vertigo and facial paralysis (FP) in patients with temporal bone trauma. The authors studied CT scans of 39 ears in 35 patients with temporal bone trauma. CT scans were performed with 1-1.5 mm slice thickness and table incrementation. Both axial and coronal scans were obtained in 32 patients and in three patients only axial scans were obtained. We analyzed CT with special reference to the structural abnormalities of the external auditory canal, middle ear cavity, bony labyrinth, and facial nerve canal, and correlated these findings with the actual clinical signs and symptoms. As to hearing loss, we evaluated 32 ears in which pure tone audiometry or brainstem evoked response audiometry had been performed. With respect to the specific types of HL, CT accurately showed the abnormalities in 84% (16/19) in conductive HL, 100% (2/2) in sensorineural HL, and 25% (2/8) for mixed HL. When we categorized HL simply as conductive and sensorineural, assuming that mixed be the result of combined conductive and sensorineural HL, CT demonstrated the abnormalities in 89% (24/27) for conductive HL and 50% (5/10) for sensorineural HL. Concerning vertigo and FP, CT demonstrated abnormalities in 67%(4/6), and 29% (4/14), respectively. Except for conductive HL, CT seems to have a variable degree of limitation for the demonstration of the structural abnormalities resulting sensorineural HL, vertigo or facial paralysis. It is imperative to correlate the CT findings with the signs and symptoms in those clinical settings

  17. Temporal bone trauma: correlative study between CT findings and clinical manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hee; Kim, Hyung Jin; Kim, Jae Hyoung [College of Medicine, Gyeongsang National University, Jinju (Korea, Republic of)

    1994-11-15

    To assess how accurately computed tomography (CT) can demonstrate the abnormal findings which are believed to cause the clinical signs and symptoms of hearing loss (HL), vertigo and facial paralysis (FP) in patients with temporal bone trauma. The authors studied CT scans of 39 ears in 35 patients with temporal bone trauma. CT scans were performed with 1-1.5 mm slice thickness and table incrementation. Both axial and coronal scans were obtained in 32 patients and in three patients only axial scans were obtained. We analyzed CT with special reference to the structural abnormalities of the external auditory canal, middle ear cavity, bony labyrinth, and facial nerve canal, and correlated these findings with the actual clinical signs and symptoms. As to hearing loss, we evaluated 32 ears in which pure tone audiometry or brainstem evoked response audiometry had been performed. With respect to the specific types of HL, CT accurately showed the abnormalities in 84% (16/19) in conductive HL, 100% (2/2) in sensorineural HL, and 25% (2/8) for mixed HL. When we categorized HL simply as conductive and sensorineural, assuming that mixed be the result of combined conductive and sensorineural HL, CT demonstrated the abnormalities in 89% (24/27) for conductive HL and 50% (5/10) for sensorineural HL. Concerning vertigo and FP, CT demonstrated abnormalities in 67%(4/6), and 29% (4/14), respectively. Except for conductive HL, CT seems to have a variable degree of limitation for the demonstration of the structural abnormalities resulting sensorineural HL, vertigo or facial paralysis. It is imperative to correlate the CT findings with the signs and symptoms in those clinical settings.

  18. Differentiating levels of surgical experience on a virtual reality temporal bone simulator.

    Science.gov (United States)

    Zhao, Yi C; Kennedy, Gregor; Hall, Richard; O'Leary, Stephen

    2010-11-01

    Virtual reality simulation is increasingly being incorporated into surgical training and may have a role in temporal bone surgical education. Here we test whether metrics generated by a virtual reality surgical simulation can differentiate between three levels of experience, namely novices, otolaryngology residents, and experienced qualified surgeons. Cohort study. Royal Victorian Eye and Ear Hospital. Twenty-seven participants were recruited. There were 12 experts, six residents, and nine novices. After orientation, participants were asked to perform a modified radical mastoidectomy on the simulator. Comparisons of time taken, injury to structures, and forces exerted were made between the groups to determine which specific metrics would discriminate experience levels. Experts completed the simulated task in significantly shorter time than the other two groups (experts 22 minutes, residents 36 minutes, and novices 46 minutes; P = 0.001). Novices exerted significantly higher average forces when dissecting close to vital structures compared with experts (0.24 Newton [N] vs 0.13 N, P = 0.002). Novices were also more likely to injure structures such as dura compared to experts (23 injuries vs 3 injuries, P = 0.001). Compared with residents, the experts modulated their force between initial cortex dissection and dissection close to vital structures. Using the combination of these metrics, we were able to correctly classify the participants' level of experience 90 percent of the time. This preliminary study shows that measurements of performance obtained from within a virtual reality simulator can differentiate between levels of users' experience. These results suggest that simulator training may have a role in temporal bone training beyond foundational training. Copyright © 2010 American Academy of Otolaryngology–Head and Neck Surgery Foundation. Published by Mosby, Inc. All rights reserved.

  19. 3D-CT of the temporal bone area with high-speed processing

    International Nuclear Information System (INIS)

    Hattori, Taku

    1994-01-01

    Three-dimentional (3D)-CT was introduced to represent abnormal findings in the temporal bone area utilizing a SOMATOM DRH CT scanner with accessory 3D reconstruction software and an exclusive high-speed 3D processing system, VOXEL FLINGER. In a patient with eosinophilic granuloma, a defect in the squamous part of the temporal bone was demonstrated suggesting exposure of the dura mater during surgery. In a patient with a normal ear, well-developed mastoid cavity, a part of the handle and the head of the malleus, the incudomalleal joint, the short limb, body and a part of the long limb of the incus and the round window niche were demonstrated. In a case of chronic otitis media, poorly developed mastoid cavity and a possible defect of the tip of the long limb of the incus were demonstrated, in contrast to the patient with the normal ear. 3D-CT yields objective and solid images which are useful for diagnosis, treatment planning and explanation of the pathology to patients and their family. To obtain convincing 3D images, physicians themselves have to choose exact rotation angles. It is not adequate to reconstruct original CT data using a CT computer with accessory 3D software whose processing capability is not good enough for this purpose. The conclusion is as follows: 1) it is necessary and effective to transfer original CT data into the memory of the exclusive high-speed 3D processing system and 2) process the data by the voxel memory method to establish a clinically valuable 3D-CT imaging system. (author)

  20. Primary giant myxoma of the temporal bone with major intracranial extension: presenting with hearing impairment and ear polyp

    Directory of Open Access Journals (Sweden)

    Satyarthee Guru Dutta

    2016-12-01

    Full Text Available Myxomas are mesenchymal origin, benign tumor, constituting approximately half of the benign cardiac tumors. Occasionally, it may also occurs at other locations, though the intracranial location of a myxoma is considered exceptionally rare. Only isolated few cases of intracranial myxoma are reported in the literature, almost all were locally confined within the originating bone. The extensive Pubmed and Medline search yielded only eight cases of primary myxoma arising in the temporal bone with extension into intracranial compartment. However intracranial extension is limited as early detection, however, Osterdock et al reported a case also arising from temporal bone with extensive intracranial extension. Author report an interesting case of intracranial myxoma in 27- year- old- male, involving the temporal bone associated with extensive bony erosion and also extending into infratemporal fossa, mastoid, and frontoparietal region and a polypoidal mass protruding into external ear. To the best of knowledge of authors, temporal myxoma presenting with external ear polypoidal mass, which underwent successful surgical excision is not reported and represent first case in the world literature.

  1. Analysis of Vibrant Soundbridge placement against the round window membrane in a human cadaveric temporal bone model.

    NARCIS (Netherlands)

    Pennings, R.J.E.; Ho, A.; Brown, J.; Wijhe, R.G. van; Bance, M.

    2010-01-01

    OBJECTIVE: To evaluate optimal placement of the Floating Mass Transducer of the Vibrant Soundbridge (Med-El, Innsbruck, Austria) against the round window membrane, particularly the impact of interposed coupling fascia and of covering materials. METHOD: : Six fresh human cadaveric temporal bones were

  2. Dual-time-point FDG-PET/CT Imaging of Temporal Bone Chondroblastoma: A Report of Two Cases

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    Akira Toriihara

    2015-07-01

    Full Text Available Temporal bone chondroblastoma is an extremely rare benign bone tumor. We encountered two cases showing similar imaging findings on computed tomography (CT, magnetic resonance imaging (MRI, and dual-time-point 18F-fluorodeoxyglucose (18F-FDG positron emission tomography (PET/CT. In both cases, CT images revealed temporal bone defects and sclerotic changes around the tumor. Most parts of the tumor showed low signal intensity on T2- weighted MRI images and non-uniform enhancement on gadolinium contrast-enhanced T1-weighted images. No increase in signal intensity was noted in diffusion-weighted images. Dual-time-point PET/CT showed markedly elevated 18F-FDG uptake, which increased from the early to delayed phase. Nevertheless, immunohistochemical analysis of the resected tumor tissue revealed weak expression of glucose transporter-1 and hexokinase II in both tumors. Temporal bone tumors, showing markedly elevated 18F-FDG uptake, which increases from the early to delayed phase on PET/CT images, may be diagnosed as malignant bone tumors. Therefore, the differential diagnosis should include chondroblastoma in combination with its characteristic findings on CT and MRI.

  3. Variation and diversity in Homo erectus: a 3D geometric morphometric analysis of the temporal bone.

    Science.gov (United States)

    Terhune, Claire E; Kimbel, William H; Lockwood, Charles A

    2007-07-01

    Although the level of taxonomic diversity within the fossil hominin species Homo erectus (sensu lato) is continually debated, there have been relatively few studies aiming to quantify the morphology of this species. Instead, most researchers have relied on qualitative descriptions or the evaluation of nonmetric characters, which in many cases display continuous variation. Also, only a few studies have used quantitative data to formally test hypotheses regarding the taxonomic composition of the "erectus" hypodigm. Despite these previous analyses, however, and perhaps in part due to these varied approaches for assessing variation within specimens typically referred to H. erectus (sensu lato) and the general lack of rigorous statistical testing of how variation within this taxon is partitioned, there is currently little consensus regarding whether this group is a single species, or whether it should instead be split into separate temporal or geographically delimited taxa. In order to evaluate possible explanations for variation within H. erectus, we tested the general hypothesis that variation within the temporal bone morphology of H. erectus is consistent with that of a single species, using great apes and humans as comparative taxa. Eighteen three-dimensional (3D) landmarks of the temporal bone were digitized on a total of 520 extant and fossil hominid crania. Landmarks were registered by Generalized Procrustes Analysis, and Procrustes distances were calculated for comparisons of individuals within and between the extant taxa. Distances between fossil specimens and between a priori groupings of fossils were then compared to the distances calculated within the extant taxa to assess the variation within the H. erectus sample relative to that of known species, subspecies, and populations. Results of these analyses indicate that shape variation within the entire H. erectus sample is generally higher than extant hominid intraspecific variation, and putative H. ergaster

  4. CT and MRI findings of temporal bone anomaly in patients with tinnitus

    Energy Technology Data Exchange (ETDEWEB)

    Bing, Wang; Junfang, Xian; Zhenchang, Wang; Zhaohui, Liu [Department of Radiology, Beijing Tongren Hospital, Capital Medical University (China)

    2011-03-15

    Objective: To study high resolution CT (HRCT) and MRI findings of temporal hone anomaly in patients with tinnitus and identify the optimal examination method in the detection of the anomaly. Methods: The HRCT and MRI data were analyzed retrospectively in 1015 patients including 145 patients with pulsatile tinnitus (PT) and 870 patients with nonpulsatile tinnitus (NPT). The positive rates of HRCT and MRI in the identification of temporal bone anomaly were analyzed and the efficiency of various examination methods was compared in revealing the anomaly. Data were tested by Chi-square test analysis. Results: Among 1015 patients, anomaly was seen in 767 cases (75.57%). High jugular bulb was found in 414 patients, accounting for 40.79%. Sigmoid sinus anomaly was detected in 387 patients (38.13%), while otitis media was found in 148 cases (14.58%), and low middle cranial fossa in 70 cases (6.90%). The positive rate of HRCT in the detection of high jugular bulb was 54.89% (365/665), which was significantly higher than those of other methods (P<0.05). The positive rate of enhanced HRCT in showing sigmoid sinus anomaly was 73.68% (56/76), which was significantly higher than those of other methods (P<0.05). Sigmoid sinus anomaly was the most frequent finding in patients with PT, accounting for 66.21% (96/145). The incidence of sigmoid sinus anomaly was higher in PT than in NPT (291/870, 33.45%; χ{sup 2}=56.537, P<0.01). The fast imaging employing steady-state acquisition (FIESTA) sequence was the best examination method in displaying the vessel within the internal auditory canal (42/42,100%). Conclusions: High jugular bulb and sigmoid sinus anomaly were the most frequent abnormal findings of temporal bone in patients with tinnitus. Enhanced HRCT was the choice of modality in patients with PT. Plain HRCT was recommended for NPT. FIESTA sequence was the best in the evaluation of the vessel within the internal auditory canal. (authors)

  5. Microsurgical and Endoscopic Anatomy for Intradural Temporal Bone Drilling and Applications of the Electromagnetic Navigation System: Various Extensions of the Retrosigmoid Approach.

    Science.gov (United States)

    Matsushima, Ken; Komune, Noritaka; Matsuo, Satoshi; Kohno, Michihiro

    2017-07-01

    The use of the retrosigmoid approach has recently been expanded by several modifications, including the suprameatal, transmeatal, suprajugular, and inframeatal extensions. Intradural temporal bone drilling without damaging vital structures inside or beside the bone, such as the internal carotid artery and jugular bulb, is a key step for these extensions. This study aimed to examine the microsurgical and endoscopic anatomy of the extensions of the retrosigmoid approach and to evaluate the clinical feasibility of an electromagnetic navigation system during intradural temporal bone drilling. Five temporal bones and 8 cadaveric cerebellopontine angles were examined to clarify the anatomy of retrosigmoid intradural temporal bone drilling. Twenty additional cerebellopontine angles were dissected in a clinical setting with an electromagnetic navigation system while measuring the target registration errors at 8 surgical landmarks on and inside the temporal bone. Retrosigmoid intradural temporal bone drilling expanded the surgical exposure to allow access to the petroclival and parasellar regions (suprameatal), internal acoustic meatus (transmeatal), upper jugular foramen (suprajugular), and petrous apex (inframeatal). The electromagnetic navigation continuously guided the drilling without line of sight limitation, and its small devices were easily manipulated in the deep and narrow surgical field in the posterior fossa. Mean target registration error was less than 0.50 mm during these procedures. The combination of endoscopic and microsurgical techniques aids in achieving optimal exposure for retrosigmoid intradural temporal bone drilling. The electromagnetic navigation system had clear advantages with acceptable accuracy including the usability of small devices without line of sight limitation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Rigidified pneumatic composites

    Science.gov (United States)

    van Dessel, Steven

    2000-10-01

    The overall objective of the research presented in this dissertation was to address global issues of adequate housing for all and the need for more sustainable human settlement. In order to address these, the emerging technology of rigidified pneumatic composites was investigated. Rigidified pneumatic composites (RPC) are defined as thin flexible membrane structures that are pneumatically deployed. After deployment, these structures harden due to chemical or physical change of the membrane. Because of this change, these structures do no longer require pneumatic pressure to maintain their shape. For the first time, a systematic listing of the various means available to develop polymeric materials useful in RPC technology is presented. With the aim to reduce the cost of RPC structures, a new material was proposed, developed, and evaluated. This material involved the formation of a semi-interpenetrating polymer network based on poly vinyl chloride and an acrylate based reactive plasticizer. The economical and environmental performances of RPC structures using this new material were assessed by means of a case study. In this study, the performance of RPC technology was compared with that of a typical wood light frame structure in the application of a small single-family house. The study indicated that the cost of ownership in present day value for the RPC structure was approximately 33% less than the cost of a comparable wood light frame structure. The study also indicated that significant environmental benefits exist with the use of RPC structures. It was found that the RPC structure used significantly less resources compared to the wood light frame structure. About 3.5 times less materials coming from non-renewable fossil resources, about 2.5 times less materials coming from trees, and about 19 times less materials coming from inorganic resources was used in the RPC structure relative to the wood light frame structure. The study concluded with pointing out various

  7. Identification of photoacoustic transients during pulsed laser ablation of the human temporal bone: an experimental model.

    Science.gov (United States)

    Wong, B J; Dickinson, M R; Berns, M W; Neev, J

    1996-12-01

    Laser ablation of hard tissues during neurotologic operations has been accomplished with continuous-wave (CW) lasers in the visible and midinfrared spectrum. The mechanism of ablation at these wavelengths is secondary to photothermal-induced tissue destruction. As a result, significant thermal damage to surrounding tissue may occur. Pulsed ultraviolet (UV) lasers have been suggested as an alternative to the argon, KTP-532, and CO2 lasers currently used in clinical practice. The pulse length of Excimer lasers are considerably shorter than the thermal diffusion time of bone tissue, and as a consequence thermal injury is minimal. This makes pulsed lasers an attractive tool for tissue ablation in the ear: in essence a "cold knife." However, the short pulse width of Excimer lasers (typically 10-150 ns) can create large thermoelastic stresses in the ablation specimen. This study identifies the presence of these photoacoustic waves during the Excimer laser treatment of the cadaveric human temporal bone. A XeCl (lambda = 308 nm, tau p = 12 ns) excimer laser was used to ablate hard tissue surrounding the oval window and facial ridge with energies of 75, 45, 25, and 12 mJ/pulse. Spot size was estimated to be 0.5 mm2. Custom high-frequency polyvinyldifluoride (PVDF) piezoelectric film transducers were fabricated and attached to the promontory, round window niche, and facial ridges. The signals were amplified using a low-noise preamplifier and recorded on a digitizing oscilloscope. Photoacoustic waves were clearly identified. Notably, large acoustic waves were measured on the promontory and on both sides of the facial ridge. The implications and clinical relevance of these findings is discussed and compared to findings obtained from a model system.

  8. Temporal variation and lack of host specificity among bacterial endosymbionts of Osedax bone worms (Polychaeta: Siboglinidae

    Directory of Open Access Journals (Sweden)

    Salathé Rahel M

    2012-09-01

    Full Text Available Abstract Background Osedax worms use a proliferative root system to extract nutrients from the bones of sunken vertebrate carcasses. The roots contain bacterial endosymbionts that contribute to the nutrition of these mouthless and gutless worms. The worms acquire these essential endosymbionts locally from the environment in which their larvae settle. Here we report on the temporal dynamics of endosymbiont diversity hosted by nine Osedax species sampled during a three-year investigation of an experimental whale fall at 1820-m depth in the Monterey Bay, California. The host species were identified by their unique mitochondrial COI haplotypes. The endosymbionts were identified by ribotyping with PCR primers specifically designed to target Oceanospirillales. Results Thirty-two endosymbiont ribotypes associated with these worms clustered into two distinct bacterial ribospecies that together comprise a monophyletic group, mostly restricted to deep waters (>1000 m. Statistical analyses confirmed significant changes in the relative abundances of host species and the two dominant endosymbiont ribospecies during the three-year sampling period. Bone type (whale vs. cow also had a significant effect on host species, but not on the two dominant symbiont ribospecies. No statistically significant association existed between the host species and endosymbiont ribospecies. Conclusions Standard PCR and direct sequencing proved to be an efficient method for ribotyping the numerically dominant endosymbiont strains infecting a large sample of host individuals; however, this method did not adequately represent the frequency of mixed infections, which appears to be the rule rather than an exception for Osedax individuals. Through cloning and the use of experimental dilution series, we determined that minority ribotypes constituting less than 30% of a mixture would not likely be detected, leading to underestimates of the frequency of multiple infections in host

  9. Temporal variation and lack of host specificity among bacterial endosymbionts of Osedax bone worms (Polychaeta: Siboglinidae)

    Science.gov (United States)

    2012-01-01

    Background Osedax worms use a proliferative root system to extract nutrients from the bones of sunken vertebrate carcasses. The roots contain bacterial endosymbionts that contribute to the nutrition of these mouthless and gutless worms. The worms acquire these essential endosymbionts locally from the environment in which their larvae settle. Here we report on the temporal dynamics of endosymbiont diversity hosted by nine Osedax species sampled during a three-year investigation of an experimental whale fall at 1820-m depth in the Monterey Bay, California. The host species were identified by their unique mitochondrial COI haplotypes. The endosymbionts were identified by ribotyping with PCR primers specifically designed to target Oceanospirillales. Results Thirty-two endosymbiont ribotypes associated with these worms clustered into two distinct bacterial ribospecies that together comprise a monophyletic group, mostly restricted to deep waters (>1000 m). Statistical analyses confirmed significant changes in the relative abundances of host species and the two dominant endosymbiont ribospecies during the three-year sampling period. Bone type (whale vs. cow) also had a significant effect on host species, but not on the two dominant symbiont ribospecies. No statistically significant association existed between the host species and endosymbiont ribospecies. Conclusions Standard PCR and direct sequencing proved to be an efficient method for ribotyping the numerically dominant endosymbiont strains infecting a large sample of host individuals; however, this method did not adequately represent the frequency of mixed infections, which appears to be the rule rather than an exception for Osedax individuals. Through cloning and the use of experimental dilution series, we determined that minority ribotypes constituting less than 30% of a mixture would not likely be detected, leading to underestimates of the frequency of multiple infections in host individuals. PMID:23006795

  10. Spectrum of temporal bone abnormalities in patients with Waardenburg syndrome and SOX10 mutations.

    Science.gov (United States)

    Elmaleh-Bergès, M; Baumann, C; Noël-Pétroff, N; Sekkal, A; Couloigner, V; Devriendt, K; Wilson, M; Marlin, S; Sebag, G; Pingault, V

    2013-01-01

    Waardenburg syndrome, characterized by deafness and pigmentation abnormalities, is clinically and genetically heterogeneous, consisting of 4 distinct subtypes and involving several genes. SOX10 mutations have been found both in types 2 and 4 Waardenburg syndrome and neurologic variants. The purpose of this study was to evaluate both the full spectrum and relative frequencies of inner ear malformations in these patients. Fifteen patients with Waardenburg syndrome and different SOX10 mutations were studied retrospectively. Imaging was performed between February 2000 and March 2010 for cochlear implant work-up, diagnosis of hearing loss, and/or evaluation of neurologic impairment. Eleven patients had both CT and MR imaging examinations, 3 had MR imaging only, and 1 had CT only. Temporal bone abnormalities were bilateral. The most frequent pattern associated agenesis or hypoplasia of ≥1 semicircular canal, an enlarged vestibule, and a cochlea with a reduced size and occasionally an abnormal shape, but with normal partition in the 13/15 cases that could be analyzed. Three patients lacked a cochlear nerve, bilaterally in 2 patients. In addition, associated abnormalities were found when adequate MR imaging sequences were available: agenesis of the olfactory bulbs (7/8), hypoplastic or absent lacrimal glands (11/14), hypoplastic parotid glands (12/14), and white matter signal anomalies (7/13). In the appropriate clinical context, bilateral agenesis or hypoplasia of the semicircular canals or both, associated with an enlarged vestibule and a cochlear deformity, strongly suggests a diagnosis of Waardenburg syndrome linked to a SOX10 mutation.

  11. The new mid-scala electrode array: a radiologic and histologic study in human temporal bones.

    Science.gov (United States)

    Hassepass, Frederike; Bulla, Stefan; Maier, Wolfgang; Laszig, Roland; Arndt, Susan; Beck, Rainer; Traser, Lousia; Aschendorff, Antje

    2014-09-01

    To analyze the quality of insertion of the newly developed midscala (MS) electrode, which targets a midscalar electrode position to reduce the risk of trauma to the lateral wall and the modiolus. Modern cochlear implant surgery aims for a safe intracochlear placement of electrode arrays with an ongoing debate regarding cochleostomy or round window (RW) insertion and the use of lateral wall or perimodiolar electrode placement. Intracochlear trauma after insertion of different electrodes depends on insertion mode and electrode design and may result in trauma to the delicate structures of the cochlear. We performed a temporal bone (TB) trial with insertion of the MS electrode in n = 20 TB's after a mastoidectomy and posterior tympanotomy. Insertion was performed either via the RW or a cochleostomy. Electrode positioning, length of insertion, and angle of insertion were analyzed with rotational tomography (RT). TBs were histologically analyzed. Results of RT and histology were compared. Scala tympani (ST) insertion could be accomplished reliably by both RW and via a cochleostomy approach. In 20 TBs, 1 scala vestibuli insertion, 1 incomplete (ST), and 1 elevation of basilar membrane were depicted. No trauma was found in 94.7% of all ST insertions. RT allowed determination of the intracochlear electrode position, which was specified by histologic sectioning. The new MS electrode seems to fulfill reliable atraumatic intracochlear placement via RW and cochleostomy approaches. RT is available for evaluation of intracochlear electrode position, serving as a potential quality control instrument in human implantation.

  12. Usefulness of temporal bone prototype for drilling training: A prospective study.

    Science.gov (United States)

    Aussedat, C; Venail, F; Nguyen, Y; Lescanne, E; Marx, M; Bakhos, D

    2017-12-01

    Dissection of cadaveric temporal bones (TBs) is considered the gold standard for surgical training in otology. For many reasons, access to the anatomical laboratory and cadaveric TBs is difficult for some facilities. The aim of this prospective and comparative study was to evaluate the usefulness of a physical TB prototype for drilling training in residency. Prospective study. Tertiary referral centre. Thirty-four residents were included. Seventeen residents (mean age 26.7±1.6) drilled on only cadaveric TBs ("traditional" group), in the traditional training method, while seventeen residents (mean age 26.5±1.7) drilled first on a prototype and then on a cadaveric TB ("prototype" group). Drilling performance was assessed using a validated scale. Residents completed a mastoid image before and after each drilling to enable evaluation of mental representations of the mastoidectomy. No differences were observed between the groups with respect to age, drilling experience and level of residency. Regarding drilling performance, we found a significant difference across the groups, with a better score in the prototype group (P=.0007). For mental representation, the score was statistically improved (P=.0003) after drilling in both groups, suggesting that TB drilling improves the mental representation of the mastoidectomy whether prototype or cadaveric TB is used. The TB prototype improves the drilling performance and mental representation of the mastoidectomy in the young resident population. A drilling simulation with virtual or physical systems seems to be a beneficial tool to improve TB drilling. © 2017 John Wiley & Sons Ltd.

  13. Operative findings of conductive hearing loss with intact tympanic membrane and normal temporal bone computed tomography.

    Science.gov (United States)

    Kim, Se-Hyung; Cho, Yang-Sun; Kim, Hye Jeong; Kim, Hyung-Jin

    2014-06-01

    Despite recent technological advances in diagnostic methods including imaging technology, it is often difficult to establish a preoperative diagnosis of conductive hearing loss (CHL) in patients with an intact tympanic membrane (TM). Especially, in patients with a normal temporal bone computed tomography (TBCT), preoperative diagnosis is more difficult. We investigated middle ear disorders encountered in patients with CHL involving an intact TM and normal TBCT. We also analyzed the surgical results with special reference to the pathology. We reviewed the medical records of 365 patients with intact TM, who underwent exploratory tympanotomy for CHL. Fifty nine patients (67 ears, eight bilateral surgeries) had a normal preoperative TBCT findings reported by neuro-radiologists. Demographic data, otologic history, TM findings, preoperative imaging findings, intraoperative findings, and pre- and postoperative audiologic data were obtained and analyzed. Exploration was performed most frequently in the second and fifth decades. The most common postoperative diagnosis was stapedial fixation with non-progressive hearing loss. The most commonly performed hearing-restoring procedure was stapedotomy with piston wire prosthesis insertion. Various types of hearing-restoring procedures during exploration resulted in effective hearing improvement, especially with better outcome in the ossicular chain fixation group. In patients with CHL who have intact TM and normal TBCT, we should consider an exploratory tympanotomy for exact diagnosis and hearing improvement. Information of the common operative findings from this study may help in preoperative counseling.

  14. Stria vascularis and cochlear hair cell changes in syphilis: A human temporal bone study.

    Science.gov (United States)

    Hızlı, Ömer; Kaya, Serdar; Hızlı, Pelin; Paparella, Michael M; Cureoglu, Sebahattin

    2016-12-01

    To observe any changes in stria vascularis and cochlear hair cells in patients with syphilis. We examined 13 human temporal bone samples from 8 patients with syphilis (our syphilis group), as well as 12 histopathologically normal samples from 9 age-matched patients without syphilis (our control group). We compared, between the two groups, the mean area of the stria vascularis (measured with conventional light microscopy connected to a personal computer) and the mean percentage of cochlear hair cell loss (obtained from cytocochleograms). In our syphilis group, only 1 (7.7%) of the 13 samples had precipitate in the endolymphatic or perilymphatic spaces; 8 (61.5%) of the samples revealed the presence of endolymphatic hydrops (4 cochlear, 4 saccular). The mean area of the stria vascularis did not significantly differ, in any turn of the cochlea, between the 2 groups (P>0.1). However, we did find significant differences between the 2 groups in the mean percentage of outer hair cells in the apical turn (Psyphilis group, we observed either complete loss of the organ of Corti or a flattened organ of Corti without any cells in addition to the absence of both outer and inner hair cells. In this study, syphilis led either to complete loss of the organ of Corti or to significant loss of cochlear hair cells, in addition to cochleosaccular hydrops. But the area of the stria vascularis did not change. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Differential Intracochlear Sound Pressure Measurements in Human Temporal Bones with an Off-the-Shelf Sensor

    Directory of Open Access Journals (Sweden)

    Martin Grossöhmichen

    2016-01-01

    Full Text Available The standard method to determine the output level of acoustic and mechanical stimulation to the inner ear is measurement of vibration response of the stapes in human cadaveric temporal bones (TBs by laser Doppler vibrometry. However, this method is reliable only if the intact ossicular chain is stimulated. For other stimulation modes an alternative method is needed. The differential intracochlear sound pressure between scala vestibuli (SV and scala tympani (ST is assumed to correlate with excitation. Using a custom-made pressure sensor it has been successfully measured and used to determine the output level of acoustic and mechanical stimulation. To make this method generally accessible, an off-the-shelf pressure sensor (Samba Preclin 420 LP, Samba Sensors was tested here for intracochlear sound pressure measurements. During acoustic stimulation, intracochlear sound pressures were simultaneously measurable in SV and ST between 0.1 and 8 kHz with sufficient signal-to-noise ratios with this sensor. The pressure differences were comparable to results obtained with custom-made sensors. Our results demonstrated that the pressure sensor Samba Preclin 420 LP is usable for measurements of intracochlear sound pressures in SV and ST and for the determination of differential intracochlear sound pressures.

  16. High-fidelity haptic and visual rendering for patient-specific simulation of temporal bone surgery.

    Science.gov (United States)

    Chan, Sonny; Li, Peter; Locketz, Garrett; Salisbury, Kenneth; Blevins, Nikolas H

    2016-12-01

    Medical imaging techniques provide a wealth of information for surgical preparation, but it is still often the case that surgeons are examining three-dimensional pre-operative image data as a series of two-dimensional images. With recent advances in visual computing and interactive technologies, there is much opportunity to provide surgeons an ability to actively manipulate and interpret digital image data in a surgically meaningful way. This article describes the design and initial evaluation of a virtual surgical environment that supports patient-specific simulation of temporal bone surgery using pre-operative medical image data. Computational methods are presented that enable six degree-of-freedom haptic feedback during manipulation, and that simulate virtual dissection according to the mechanical principles of orthogonal cutting and abrasive wear. A highly efficient direct volume renderer simultaneously provides high-fidelity visual feedback during surgical manipulation of the virtual anatomy. The resulting virtual surgical environment was assessed by evaluating its ability to replicate findings in the operating room, using pre-operative imaging of the same patient. Correspondences between surgical exposure, anatomical features, and the locations of pathology were readily observed when comparing intra-operative video with the simulation, indicating the predictive ability of the virtual surgical environment.

  17. Computer tomography in children and adolescents with suspected malformation of the petrous portion of the temporal bone

    International Nuclear Information System (INIS)

    Koesling, S.; Schneider-Moebius, C.; Koenig, E.; Meister, E.F.

    1997-01-01

    Purpose: To demonstrate HRCT findings and their therapeutic relevance in suspected congenital hearing disorders. Material and Methods: It was checked in 96 young patients if HRCT findings of the temporal bone could explain functional findings. Furthermore, the therapeutic consequences were noted. Results: Normal CT and normal functional findings were obtained in 49 temporal bones (TB). In conductive hearing loss (41 TB), dysplasias of the conducting apparatus (37 TB) and inflammatory changes (3 TB) were found. Combined hearing loss (18 TB) was clarified completely or partially in half the cases. There were 22 dysplasias of the inner ear, 3 dysplasias of the middle ear, 1 adandoned examination (2 TB), and 55 normal CT findings in senorineural hearing disorders (82 TB). 1 retardate had a malformation of the inner ear and, contralaterally, inflammatory middle ear. In cases of vestibular disorders (24 TB), 14 malformations of the inner ear were detected. (orig./AJ) [de

  18. Application of digital tomosynthesis to radiographic diagnosis of the temporal bone. Studies on visualization in normal subjects

    International Nuclear Information System (INIS)

    Kawai, Takashi

    1995-01-01

    To examine the usefulness of digital tomosynthesis for conducting radiographic diagnosis of the temporal bone, visualization of various aural structures such as the semicircular canals, cochlea, vestibular apparatus, ossicles of the ear and facial nerve canal was examined in 18 volunteers. The visualization of temporal bone specimens by digital tomosynthesis and CT images (slice thickness: 1.5 mm) was compared. The results showed that this system (Digital Tomosynthesis) produced clear images of bony labyrinthine structures such as the semicircular canals, cochlea, and vestibular apparatus. Visualization of the ossicles was also clear, and their continuity could be comprehended better than on CT images. This system also provided good visualization of the labyrinthine and tympanic parts of the facial nerve canal, although CT images had greater sharpness. Visualization of the lower half of the mastoid part was poor with this system. (author)

  19. Temporal mechanically-induced signaling events in bone and dorsal root ganglion neurons after in vivo bone loading.

    Directory of Open Access Journals (Sweden)

    Jason A Bleedorn

    Full Text Available Mechanical signals play an integral role in the regulation of bone mass and functional adaptation to bone loading. The osteocyte has long been considered the principle mechanosensory cell type in bone, although recent evidence suggests the sensory nervous system may play a role in mechanosensing. The specific signaling pathways responsible for functional adaptation of the skeleton through modeling and remodeling are not clearly defined. In vitro studies suggest involvement of intracellular signaling through mitogen-activated protein kinase (MAPK, phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt, and mammalian target of rapamycin (mTOR. However, anabolic signaling responses to bone loading using a whole animal in vivo model have not been studied in detail. Therefore, we examined mechanically-induced signaling events at five time points from 0 to 24 hours after loading using the rat in vivo ulna end-loading model. Western blot analysis of bone for MAPK's, PI3K/Akt, and mTOR signaling, and quantitative reverse transcription polymerase chain reaction (qRT-PCR to estimate gene expression of calcitonin gene-related protein alpha (CGRP-α, brain-derived neurotrophic factor (BDNF, nerve growth factor (NGF, c-jun, and c-fos in dorsal root ganglion (DRG of the brachial intumescence were performed. There was a significant increase in signaling through MAPK's including extracellular signal-related kinase (ERK and c-Jun N-terminal kinase (JNK in loaded limbs at 15 minutes after mechanical loading. Ulna loading did not significantly influence expression of the genes of interest in DRG neurons. Bone signaling and DRG gene expression from the loaded and contralateral limbs was correlated (SR>0.40, P<0.05. However, bone signaling did not correlate with expression of the genes of interest in DRG neurons. These results suggest that signaling through the MAPK pathway may be involved in load-induced bone formation in vivo. Further characterization of the

  20. Soft, Rotating Pneumatic Actuator.

    Science.gov (United States)

    Ainla, Alar; Verma, Mohit S; Yang, Dian; Whitesides, George M

    2017-09-01

    This article describes a soft pneumatic actuator that generates cyclical motion. The actuator consists of several (three, four, or five) chambers (arranged around the circumference of a circle surrounding a central rod) that can be actuated independently using negative pressure (or partial vacuum). Sequential actuation of the four-chamber device using reduced pressure moves the central rod cyclically in an approximately square path. We characterize the trajectory of the actuator and the force exerted by it, as we vary the material used for fabrication, the number of chambers, and the size of the actuator. We demonstrate two applications of this actuator: to deliver fluid while stirring (by replacing the central rod with a needle) and for locomotion that mimics a reptilian gait (by combining four actuators together).

  1. Improving temporal bone dissection using self-directed virtual reality simulation: results of a randomized blinded control trial.

    Science.gov (United States)

    Zhao, Yi Chen; Kennedy, Gregor; Yukawa, Kumiko; Pyman, Brian; O'Leary, Stephen

    2011-03-01

    A significant benefit of virtual reality (VR) simulation is the ability to provide self-direct learning for trainees. This study aims to determine whether there are any differences in performance of cadaver temporal bone dissections between novices who received traditional teaching methods and those who received unsupervised self-directed learning in a VR temporal bone simulator. Randomized blinded control trial. Royal Victorian Eye and Ear Hospital. Twenty novice trainees. After receiving an hour lecture, participants were randomized into 2 groups to receive an additional 2 hours of training via traditional teaching methods or self-directed learning using a VR simulator with automated guidance. The simulation environment presented participants with structured training tasks, which were accompanied by real-time computer-generated feedback as well as real operative videos and photos. After the training, trainees were asked to perform a cortical mastoidectomy on a cadaveric temporal bone. The dissection was videotaped and assessed by 3 otologists blinded to participants' teaching group. The overall performance scores of the simulator-based training group were significantly higher than those of the traditional training group (67% vs 29%; P < .001), with an intraclass correlation coefficient of 0.93, indicating excellent interrater reliability. Using other assessments of performance, such as injury size, the VR simulator-based training group also performed better than the traditional group. This study indicates that self-directed learning on VR simulators can be used to improve performance on cadaver dissection in novice trainees compared with traditional teaching methods alone.

  2. New total ossicular replacement prostheses with a resilient joint: experimental data from human temporal bones.

    Science.gov (United States)

    Arechvo, Irina; Bornitz, Matthias; Lasurashvili, Nikoloz; Zahnert, Thomas; Beleites, Thomas

    2012-01-01

    New flexible total ossicular prostheses with an integrated microjoint can compensate for large static displacements in the reconstructed ossicular chain. When properly designed, they can mimic the function of the joints of the intact chain and ensure good vibration transfer in both straight and bent conditions. Prosthesis dislocations and extrusions are frequently observed after middle ear surgery. They are mainly related to the altered distance between the coupling points because of large static eardrum displacements. The new prostheses consist of 2 titanium shafts, which are incorporated into a silicone body. The sound transfer function and stapes footplate displacement at static loads were evaluated in human temporal bones after ossicular reconstruction using prostheses with 2 different silicones with different hardness values. The stiffness and bending characteristics of the prostheses were investigated with a quasi-static load. The sound transfer properties of the middle ears with the prostheses inserted under uncompressed conditions were comparable with those of ears with intact ossicular chains. The implant with the soft silicone had improved acoustic transfer characteristics over the implant with the hard silicone in a compressed state. In the quasi-static experiments, the minimum medial footplate displacement was found with the same implant. The bending characteristics depended on the silicone stiffness and correlated closely with the point and angle of the load incidence. The titanium prostheses with a resilient joint that were investigated in this study had good sound transfer characteristics under optimal conditions as well as in a compressed state. As a result of joint bending, the implants compensate for the small changes in length of the ossicular chain that occur under varying middle ear pressure. The implants require a stable support at the stapes footplate to function properly.

  3. Soft Pneumatic Actuators for Rehabilitation

    Directory of Open Access Journals (Sweden)

    Guido Belforte

    2014-05-01

    Full Text Available Pneumatic artificial muscles are pneumatic devices with practical and various applications as common actuators. They, as human muscles, work in agonistic-antagonistic way, giving a traction force only when supplied by compressed air. The state of the art of soft pneumatic actuators is here analyzed: different models of pneumatic muscles are considered and evolution lines are presented. Then, the use of Pneumatic Muscles (PAM in rehabilitation apparatus is described and the general characteristics required in different applications are considered, analyzing the use of proper soft actuators with various technical properties. Therefore, research activity carried out in the Department of Mechanical and Aerospace Engineering in the field of soft and textile actuators is presented here. In particular, pneumatic textile muscles useful for active suits design are described. These components are made of a tubular structure, with an inner layer of latex coated with a deformable outer fabric sewn along the edge. In order to increase pneumatic muscles forces and contractions Braided Pneumatic Muscles are studied. In this paper, new prototypes are presented, based on a fabric construction and various kinds of geometry. Pressure-force-deformation tests results are carried out and analyzed. These actuators are useful for rehabilitation applications. In order to reproduce the whole upper limb movements, new kind of soft actuators are studied, based on the same principle of planar membranes deformation. As an example, the bellows muscle model and worm muscle model are developed and described. In both cases, wide deformations are expected. Another issue for soft actuators is the pressure therapy. Some textile sleeve prototypes developed for massage therapy on patients suffering of lymph edema are analyzed. Different types of fabric and assembly techniques have been tested. In general, these Pressure Soft Actuators are useful for upper/lower limbs treatments

  4. Spatial and temporal changes of subchondral bone proceed to articular cartilage degeneration in rats subjected to knee immobilization.

    Science.gov (United States)

    Xu, Lei; Li, Zhe; Lei, Lei; Zhou, Yue-Zhu; Deng, Song-Yun; He, Yong-Bin; Ni, Guo-Xin

    2016-03-01

    This study was aimed to investigate the spatial and temporal changes of subchondral bone and its overlying articular cartilage in rats following knee immobilization. A total of 36 male Wistar rats (11-13 months old) were assigned randomly and evenly into 3 groups. For each group, knee joints in 6 rats were immobilized unilaterally for 1, 4, or 8 weeks, respectively, while the remaining rats were allowed free activity and served as external control groups. For each animal, femurs at both sides were dissected after sacrificed. The distal part of femur was examined by micro-CT. Subsequently, femoral condyles were collected for further histological observation and analysis. For articular cartilage, significant changes were observed only at 4 and 8 weeks of immobilization. The thickness of articular cartilage and chondrocytes numbers decreased with time. However, significant changes in subchondral bone were defined by micro-CT following immobilization in a time-dependent manner. Immobilization led to a thinner and more porous subchondral bone plate, as well as a reduction in trabecular thickness and separation with a more rod-like architecture. Changes in subchondral bone occurred earlier than in articular cartilage. More importantly, immobilization-induced changes in subchondral bone may contribute, at least partially, to changes in its overlying articular cartilage. © 2016 Wiley Periodicals, Inc.

  5. Mastoiditis and facial paralysis as initial manifestations of temporal bone systemic diseases - the significance of the histopathological examination.

    Science.gov (United States)

    Maniu, Alma Aurelia; Harabagiu, Oana; Damian, Laura Otilia; Ştefănescu, Eugen HoraŢiu; FănuŢă, Bogdan Marius; Cătană, Andreea; Mogoantă, Carmen Aurelia

    2016-01-01

    Several systemic diseases, including granulomatous and infectious processes, tumors, bone disorders, collagen-vascular and other autoimmune diseases may involve the middle ear and temporal bone. These diseases are difficult to diagnose when symptoms mimic acute otomastoiditis. The present report describes our experience with three such cases initially misdiagnosed. Their predominating symptoms were otological with mastoiditis, hearing loss, and subsequently facial nerve palsy. The cases were considered an emergency and the patients underwent tympanomastoidectomy, under the suspicion of otitis media with cholesteatoma, in order to remove a possible abscess and to decompress the facial nerve. The common features were the presence of severe granulation tissue filling the mastoid cavity and middle ear during surgery, without cholesteatoma. The definitive diagnoses was made by means of biopsy of the granulation tissue from the middle ear, revealing granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) in one case, middle ear tuberculosis and diffuse large B-cell lymphoma respectively. After specific associated therapy facial nerve functions improved, and atypical inflammatory states of the ear resolved. As a group, systemic diseases of the middle ear and temporal bone are uncommon, but aggressive lesions. After analyzing these cases and reviewing the literature, we would like to stress upon the importance of microscopic examination of the affected tissue, required for an accurate diagnosis and effective treatment.

  6. Temporal bone CT findings of tuberculous otitis media : comparison with chronic otitis media

    International Nuclear Information System (INIS)

    Chang, Jeong A; Rho, Myung Ho; Kim, Young Min; Lee, Ho Seung; Choi, Pil Yeob; Seong, Young Soon; Kwon, Jae Soo; Lee, Sang Wook; Jung, Keon Sik

    1999-01-01

    To compare the differential findings of tuberculous otitis media(TOM) with those of chronic sup purative otitis media with or without cholesteatoma, as seen on high resolution temporal bone CT. We retrospectively reviewed 14 cases of TOM, 30 cases of chronic suppurative otitis media(CSOM), and 30 cases of chronic otitis media with cholesteatoma(Chole). All had been pathologically confirmed. We evaluated the preservation of mastoid cells without sclerotic change, the location and extension of soft tissue to the external auditary canal, and erosion of ossicles, the tegmen tympani, scutum, bony labyrinth, facial nerve canal and sigmoid sinus, and the presence of intracranial complications. Soft tissue in the mastoid antrum was seen in all cases of TOM(100%), 29 cases of CSOM(96.7%), and 26 cases of Chole(86.7%). In contrast, the soft tissue in the entire middle ear cavity was noted in 13 cases of TOM(92.8%), 7 cases of CSOM(23.3%), and 12 cases of Chole(40%). Soft tissue extended to the superior aspect of the external auditory canal in 4 cases of TOM (28.6%) and 5 cases of Chole (16.7%). Mastoid air cells were seen in 9 cases of TOM (64.3%), 4 cases of CSOM (13.3%), and 3 cases of Chole(10%). Ossicular erosion was noted in 6 cases of TOM (42.9%), 12 cases of CSOM (40%), and 26 cases of Chole(86.7%), while in one case of TOM (7.1%), 5 cases of CSOM (16.7%), and 15 cases of Chole(50%) there was erosion of the scutum. In one case of TOM, follow-up CT study after 9 months of antituberculous medication without surgery revealed complete clearing of previously noted soft tissue in the middle ear cavity. Specific CT findings of TOM were not seen, but if there were findings of soft tissue in the entire middle ear cavity, soft tissue extension to the external auditory canal, preservation of mastoid air cells without sclerotic change, and intact scutum, TOM may be differentiated from other chronic otitis media

  7. Temporal bone CT findings of tuberculous otitis media : comparison with chronic otitis media

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jeong A; Rho, Myung Ho; Kim, Young Min; Lee, Ho Seung; Choi, Pil Yeob; Seong, Young Soon; Kwon, Jae Soo; Lee, Sang Wook [Masan Samsung Hospital, Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of); Jung, Keon Sik [Pohang Sunrin Hospital, Pohang (Korea, Republic of)

    1999-06-01

    To compare the differential findings of tuberculous otitis media(TOM) with those of chronic sup purative otitis media with or without cholesteatoma, as seen on high resolution temporal bone CT. We retrospectively reviewed 14 cases of TOM, 30 cases of chronic suppurative otitis media(CSOM), and 30 cases of chronic otitis media with cholesteatoma(Chole). All had been pathologically confirmed. We evaluated the preservation of mastoid cells without sclerotic change, the location and extension of soft tissue to the external auditary canal, and erosion of ossicles, the tegmen tympani, scutum, bony labyrinth, facial nerve canal and sigmoid sinus, and the presence of intracranial complications. Soft tissue in the mastoid antrum was seen in all cases of TOM(100%), 29 cases of CSOM(96.7%), and 26 cases of Chole(86.7%). In contrast, the soft tissue in the entire middle ear cavity was noted in 13 cases of TOM(92.8%), 7 cases of CSOM(23.3%), and 12 cases of Chole(40%). Soft tissue extended to the superior aspect of the external auditory canal in 4 cases of TOM (28.6%) and 5 cases of Chole (16.7%). Mastoid air cells were seen in 9 cases of TOM (64.3%), 4 cases of CSOM (13.3%), and 3 cases of Chole(10%). Ossicular erosion was noted in 6 cases of TOM (42.9%), 12 cases of CSOM (40%), and 26 cases of Chole(86.7%), while in one case of TOM (7.1%), 5 cases of CSOM (16.7%), and 15 cases of Chole(50%) there was erosion of the scutum. In one case of TOM, follow-up CT study after 9 months of antituberculous medication without surgery revealed complete clearing of previously noted soft tissue in the middle ear cavity. Specific CT findings of TOM were not seen, but if there were findings of soft tissue in the entire middle ear cavity, soft tissue extension to the external auditory canal, preservation of mastoid air cells without sclerotic change, and intact scutum, TOM may be differentiated from other chronic otitis media.

  8. The temporal expression of estrogen receptor alpha-36 and runx2 in human bone marrow derived stromal cells during osteogenesis

    International Nuclear Information System (INIS)

    Francis, W.R.; Owens, S.E.; Wilde, C.; Pallister, I.; Kanamarlapudi, V.; Zou, W.; Xia, Z.

    2014-01-01

    Highlights: • ERα36 is the predominant ERα isoform involved in bone regulation in human BMSC. • ERα36 mRNA is significantly upregulated during the process of osteogenesis. • The pattern of ERα36 and runx2 mRNA expression is similar during osteogenesis. • ERα36 appears to be co-localised with runx2 during osteogenesis. - Abstract: During bone maintenance in vivo, estrogen signals through estrogen receptor (ER)-α. The objectives of this study were to investigate the temporal expression of ERα36 and ascertain its functional relevance during osteogenesis in human bone marrow derived stromal cells (BMSC). This was assessed in relation to runt-related transcription factor-2 (runx2), a main modulatory protein involved in bone formation. ERα36 and runx2 subcellular localisation was assessed using immunocytochemistry, and their mRNA expression levels by real time PCR throughout the process of osteogenesis. The osteogenically induced BMSCs demonstrated a rise in ERα36 mRNA during proliferation followed by a decline in expression at day 10, which represents a change in dynamics within the culture between the proliferative stage and the differentiative stage. The mRNA expression profile of runx2 mirrored that of ERα36 and showed a degree subcellular co-localisation with ERα36. This study suggests that ERα36 is involved in the process of osteogenesis in BMSCs, which has implications in estrogen deficient environments

  9. Does colon cancer ever metastasize to bone first? a temporal analysis of colorectal cancer progression

    International Nuclear Information System (INIS)

    Roth, Eira S; Fetzer, David T; Barron, Bruce J; Joseph, Usha A; Gayed, Isis W; Wan, David Q

    2009-01-01

    It is well recognized that colorectal cancer does not frequently metastasize to bone. The aim of this retrospective study was to establish whether colorectal cancer ever bypasses other organs and metastasizes directly to bone and whether the presence of lung lesions is superior to liver as a better predictor of the likelihood and timing of bone metastasis. We performed a retrospective analysis on patients with a clinical diagnosis of colon cancer referred for staging using whole-body 18 F-FDG PET and CT or PET/CT. We combined PET and CT reports from 252 individuals with information concerning patient history, other imaging modalities, and treatments to analyze disease progression. No patient had isolated osseous metastasis at the time of diagnosis, and none developed isolated bone metastasis without other organ involvement during our survey period. It took significantly longer for colorectal cancer patients to develop metastasis to the lungs (23.3 months) or to bone (21.2 months) than to the liver (9.8 months). Conclusion: Metastasis only to bone without other organ involvement in colorectal cancer patients is extremely rare, perhaps more rare than we previously thought. Our findings suggest that resistant metastasis to the lungs predicts potential disease progression to bone in the colorectal cancer population better than liver metastasis does

  10. The 'temporal effect' in hominids: Reinvestigating the nature of support for a chimp-human clade in bone morphology.

    Science.gov (United States)

    Pearson, Alannah; Groves, Colin; Cardini, Andrea

    2015-11-01

    In 2004, an analysis by Lockwood and colleagues of hard-tissue morphology, using geometric morphometrics on the temporal bone, succeeded in recovering the correct phylogeny of living hominids without resorting to potentially problematic methods for transforming continuous shape variables into meristic characters. That work has increased hope that by using modern analytical methods and phylogenetically informative anatomical data we might one day be able to accurately infer the relationships of hominins, including the closest extinct relatives of modern humans. In the present study, using 3D virtually generated models of the hominid temporal bone and a larger suite of geometric morphometric and comparative techniques, we have re-examined the evidence for a Pan-Homo clade. Despite differences in samples, as well as the type of raw data, the effect of measurement error (and especially landmark digitization by a different operator), but also a broader perspective brought in by our diverse set of approaches, our reanalysis largely supports Lockwood and colleagues' original results. However, by focusing not only mainly on shape (as in the original 2004 analysis) but also on size and 'size-corrected' (non-allometric) shape, we demonstrate that the strong phylogenetic signal in the temporal bone is largely related to similarities in size. Thus, with this study, we are not suggesting the use of a single 'character', such as size, for phylogenetic inference, but we do challenge the common view that shape, with its highly complex and multivariate nature, is necessarily more phylogenetically informative than size and that actually size and size-related shape variation (i.e., allometry) confound phylogenetic inference based on morphology. This perspective may in fact be less generalizable than often believed. Thus, while we confirm the original findings by Lockwood et al., we provide a deep reinterpretation of their nature and potential implications for hominid phylogenetics

  11. Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality.

    Science.gov (United States)

    Nauer, Claude Bertrand; Zubler, Christoph; Weisstanner, Christian; Stieger, Christof; Senn, Pascal; Arnold, Andreas

    2012-03-01

    The purpose of this experimental study was to investigate the effect of tube tension reduction on image contrast and image quality in pediatric temporal bone computed tomography (CT). Seven lamb heads with infant-equivalent sizes were scanned repeatedly, using four tube tensions from 140 to 80 kV while the CT-Dose Index (CTDI) was held constant. Scanning was repeated with four CTDI values from 30 to 3 mGy. Image contrast was calculated for the middle ear as the Hounsfield unit (HU) difference between bone and air and for the inner ear as the HU difference between bone and fluid. The influence of tube tension on high-contrast detail delineation was evaluated using a phantom. The subjective image quality of eight middle and inner ear structures was assessed using a 4-point scale (scores 1-2 = insufficient; scores 3-4 = sufficient). Middle and inner ear contrast showed a near linear increase with tube tension reduction (r = -0.94/-0.88) and was highest at 80 kV. Tube tension had no influence on spatial resolution. Subjective image quality analysis showed significantly better scoring at lower tube tensions, with highest image quality at 80 kV. However, image quality improvement was most relevant for low-dose scans. Image contrast in the temporal bone is significantly higher at low tube tensions, leading to a better subjective image quality. Highest contrast and best quality were found at 80 kV. This image quality improvement might be utilized to further reduce the radiation dose in pediatric low-dose CT protocols.

  12. Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality

    International Nuclear Information System (INIS)

    Nauer, Claude Bertrand; Zubler, Christoph; Weisstanner, Christian; Stieger, Christof; Senn, Pascal; Arnold, Andreas

    2012-01-01

    The purpose of this experimental study was to investigate the effect of tube tension reduction on image contrast and image quality in pediatric temporal bone computed tomography (CT). Seven lamb heads with infant-equivalent sizes were scanned repeatedly, using four tube tensions from 140 to 80 kV while the CT-Dose Index (CTDI) was held constant. Scanning was repeated with four CTDI values from 30 to 3 mGy. Image contrast was calculated for the middle ear as the Hounsfield unit (HU) difference between bone and air and for the inner ear as the HU difference between bone and fluid. The influence of tube tension on high-contrast detail delineation was evaluated using a phantom. The subjective image quality of eight middle and inner ear structures was assessed using a 4-point scale (scores 1-2 = insufficient; scores 3-4 = sufficient). Middle and inner ear contrast showed a near linear increase with tube tension reduction (r = -0.94/-0.88) and was highest at 80 kV. Tube tension had no influence on spatial resolution. Subjective image quality analysis showed significantly better scoring at lower tube tensions, with highest image quality at 80 kV. However, image quality improvement was most relevant for low-dose scans. Image contrast in the temporal bone is significantly higher at low tube tensions, leading to a better subjective image quality. Highest contrast and best quality were found at 80 kV. This image quality improvement might be utilized to further reduce the radiation dose in pediatric low-dose CT protocols. (orig.)

  13. CT examination of the temporal bones for cochlear implantation; Badanie CT kosci skroniowych u osob przygotowanych do operacji wszczepu slimakowego

    Energy Technology Data Exchange (ETDEWEB)

    Szyfter, W.; Szymiec, E.; Pruszewicz, A.; Szmeja, Z.; Paprzycki, W.; Sekula, A.; Przybylska, J. [Klinika Otolaryngologii, Akademia Medyczna, Poznan (Poland)

    1995-12-31

    CT examinations of temporal bones were performed in 31 deaf patients from qualify diagnostic stage prepared for cochlear implants. Essential for surgical treatment anatomic details were estimated, especially canalis spiralis cochleae was paid to attention. In our group, 8 patients had some CT changes (abnormal findings) which corresponded to different stages of obliteration the cochlea. The majority of patients lost the hearing because of meningitis. In 6 implanted patients CT scan was compared with surgical findings. During the operation 1 patient with patent cochlea on CT scan had partially ossified basal turn. (author) 16 refs, 4 figs, 2 tabs

  14. Temporal bone extramedullary hematopoiesis as a causeof pediatric bilateral conductive hearing loss:Case report and review of the literature.

    Science.gov (United States)

    Lanigan, Alexander; Fordham, M Taylor

    2017-06-01

    Extramedullary hematopoiesis occurs in children with hemoglobinopathy and chronic anemia. The liver and spleen are often affected first, but other foci can develop to support erythrocyte demand. We report a case of a nine-year-old with beta thalassemia and temporal bone extramedullary hematopoiesis causing ossicular fixation and bilateral conductive hearing loss. There is only one case in the literature describing this phenomenon in pediatric patients, and this is the first case report of bilateral hearing loss from this physiologic phenomenon. Otolaryngologists should consider this etiology in patients with chronic anemia and conductive hearing loss in the absence of otitis media. Published by Elsevier B.V.

  15. The characteristics of a pneumatic muscle

    OpenAIRE

    Pietrala Dawid

    2017-01-01

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles s...

  16. High strength, biodegradable and cytocompatible alpha tricalcium phosphate-iron composites for temporal reduction of bone fractures.

    Science.gov (United States)

    Montufar, E B; Casas-Luna, M; Horynová, M; Tkachenko, S; Fohlerová, Z; Diaz-de-la-Torre, S; Dvořák, K; Čelko, L; Kaiser, J

    2018-04-01

    In this work alpha tricalcium phosphate (α-TCP)/iron (Fe) composites were developed as a new family of biodegradable, load-bearing and cytocompatible materials. The composites with composition from pure ceramic to pure metallic samples were consolidated by pulsed electric current assisted sintering to minimise processing time and temperature while improving their mechanical performance. The mechanical strength of the composites was increased and controlled with the Fe content, passing from brittle to ductile failure. In particular, the addition of 25 vol% of Fe produced a ceramic matrix composite with elastic modulus much closer to cortical bone than that of titanium or biodegradable magnesium alloys and specific compressive strength above that of stainless steel, chromium-cobalt alloys and pure titanium, currently used in clinic for internal fracture fixation. All the composites studied exhibited higher degradation rate than their individual components, presenting values around 200 μm/year, but also their compressive strength did not show a significant reduction in the period required for bone fracture consolidation. Composites showed preferential degradation of α-TCP areas rather than β-TCP areas, suggesting that α-TCP can produce composites with higher degradation rate. The composites were cytocompatible both in indirect and direct contact with bone cells. Osteoblast-like cells attached and spread on the surface of the composites, presenting proliferation rate similar to cells on tissue culture-grade polystyrene and they showed alkaline phosphatase activity. Therefore, this new family of composites is a potential alternative to produce implants for temporal reduction of bone fractures. Biodegradable alpha-tricalcium phosphate/iron (α-TCP/Fe) composites are promising candidates for the fabrication of temporal osteosynthesis devices. Similar to biodegradable metals, these composites can avoid implant removal after bone fracture healing, particularly in

  17. Two developmentally temporal quantitative trait loci underlie convergent evolution of increased branchial bone length in sticklebacks

    Science.gov (United States)

    Erickson, Priscilla A.; Glazer, Andrew M.; Cleves, Phillip A.; Smith, Alyson S.; Miller, Craig T.

    2014-01-01

    In convergent evolution, similar phenotypes evolve repeatedly in independent populations, often reflecting adaptation to similar environments. Understanding whether convergent evolution proceeds via similar or different genetic and developmental mechanisms offers insight towards the repeatability and predictability of evolution. Oceanic populations of threespine stickleback fish, Gasterosteus aculeatus, have repeatedly colonized countless freshwater lakes and streams, where new diets lead to morphological adaptations related to feeding. Here, we show that heritable increases in branchial bone length have convergently evolved in two independently derived freshwater stickleback populations. In both populations, an increased bone growth rate in juveniles underlies the convergent adult phenotype, and one population also has a longer cartilage template. Using F2 crosses from these two freshwater populations, we show that two quantitative trait loci (QTL) control branchial bone length at distinct points in development. In both populations, a QTL on chromosome 21 controls bone length throughout juvenile development, and a QTL on chromosome 4 controls bone length only in adults. In addition to these similar developmental profiles, these QTL show similar chromosomal locations in both populations. Our results suggest that sticklebacks have convergently evolved longer branchial bones using similar genetic and developmental programmes in two independently derived populations. PMID:24966315

  18. [A temporal bone CT study of the infants with hearing loss referred from universal newborn hearing screening].

    Science.gov (United States)

    Tao, Zheng; Li, Yun; Hou, Zheng; Cheng, Lan

    2007-02-01

    To explore the high resolution CT image of temporal bone in infants with hearing loss, and its value in evaluating the cause of hearing loss. In 2005, 0.12 million newborns have been included in the hearing screening system in Shanghai, and 1077 infants have failed to pass the hearing screening. One hundred and eight four infants were diagnosed as congenital hearing loss from mild to profound. A temporal bone HRCT scanning was performed to these infants. Among the 184 patients with congenital hearing loss, HRCT showed that 26 cases (14.1%) were associated with external ear malformation, and 21 cases (11.4%) were associated with middle ear malformation, 31 cases (16.8%) associated with inner ear malformation. The patients with inner ear malformation included 12 cases with Mondini malformation, 1 case with common cavity malformation, 6 cases with large vestibule malformation, 5 cases with internal auditory canal abnormalities, and 10 cases with vestibule, semicircular canals abnormalities. In addition, there were 20 cases (10.8%) with fluid in middle ear. HRCT image play an important role in the differential diagnosis and treatment of infants with congenital hearing loss.

  19. Temporal trends in obesity, osteoporosis treatment, bone mineral density, and fracture rates: a population-based historical cohort study.

    Science.gov (United States)

    Leslie, William D; Lix, Lisa M; Yogendran, Marina S; Morin, Suzanne N; Metge, Colleen J; Majumdar, Sumit R

    2014-04-01

    Diverging international trends in fracture rates have been observed, with most reports showing that fracture rates have stabilized or decreased in North American and many European populations. We studied two complementary population-based historical cohorts from the Province of Manitoba, Canada (1996-2006) to determine whether declining osteoporotic fracture rates in Canada are attributable to trends in obesity, osteoporosis treatment, or bone mineral density (BMD). The Population Fracture Registry included women aged 50 years and older with major osteoporotic fractures, and was used to assess impact of changes in osteoporosis treatment. The BMD Registry included all women aged 50 years and older undergoing BMD tests, and was used to assess impact of changes in obesity and BMD. Model-based estimates of temporal changes in fracture rates (Fracture Registry) were calculated. Temporal changes in obesity and BMD and their association with fracture rates (BMD Registry) were estimated. In the Fracture Registry (n=27,341), fracture rates declined 1.6% per year (95% confidence interval [CI], 1.3% to 2.0%). Although osteoporosis treatment increased from 5.6% to 17.4%, the decline in fractures was independent of osteoporosis treatment. In the BMD Registry (n=36,587), obesity increased from 12.7% to 27.4%. Femoral neck BMD increased 0.52% per year and lumbar spine BMD increased 0.32% per year after covariate adjustment (pobesity or osteoporosis treatment. © 2014 American Society for Bone and Mineral Research.

  20. The characteristics of a pneumatic muscle

    Directory of Open Access Journals (Sweden)

    Pietrala Dawid

    2017-01-01

    Full Text Available The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics. It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics. It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics. The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  1. The characteristics of a pneumatic muscle

    Science.gov (United States)

    Pietrala, Dawid

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  2. Hypoglossal-facial nerve "side"-to-side neurorrhaphy for facial paralysis resulting from closed temporal bone fractures.

    Science.gov (United States)

    Su, Diya; Li, Dezhi; Wang, Shiwei; Qiao, Hui; Li, Ping; Wang, Binbin; Wan, Hong; Schumacher, Michael; Liu, Song

    2018-06-06

    Closed temporal bone fractures due to cranial trauma often result in facial nerve injury, frequently inducing incomplete facial paralysis. Conventional hypoglossal-facial nerve end-to-end neurorrhaphy may not be suitable for these injuries because sacrifice of the lesioned facial nerve for neurorrhaphy destroys the remnant axons and/or potential spontaneous innervation. we modified the classical method by hypoglossal-facial nerve "side"-to-side neurorrhaphy using an interpositional predegenerated nerve graft to treat these injuries. Five patients who experienced facial paralysis resulting from closed temporal bone fractures due to cranial trauma were treated with the "side"-to-side neurorrhaphy. An additional 4 patients did not receive the neurorrhaphy and served as controls. Before treatment, all patients had suffered House-Brackmann (H-B) grade V or VI facial paralysis for a mean of 5 months. During the 12-30 months of follow-up period, no further detectable deficits were observed, but an improvement in facial nerve function was evidenced over time in the 5 neurorrhaphy-treated patients. At the end of follow-up, the improved facial function reached H-B grade II in 3, grade III in 1 and grade IV in 1 of the 5 patients, consistent with the electrophysiological examinations. In the control group, two patients showed slightly spontaneous innervation with facial function improved from H-B grade VI to V, and the other patients remained unchanged at H-B grade V or VI. We concluded that the hypoglossal-facial nerve "side"-to-side neurorrhaphy can preserve the injured facial nerve and is suitable for treating significant incomplete facial paralysis resulting from closed temporal bone fractures, providing an evident beneficial effect. Moreover, this treatment may be performed earlier after the onset of facial paralysis in order to reduce the unfavorable changes to the injured facial nerve and atrophy of its target muscles due to long-term denervation and allow axonal

  3. Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

    International Nuclear Information System (INIS)

    Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul

    2001-01-01

    To identify and evaluate the normal anatomy of nerve canals in the fundus of the internal auditory canal which can be visualized on high-resolution temporal bone CT. We retrospectively reviewed high-resolution (1 mm thickness and interval contiguous scan) temporal bone CT images of 253 ears in 150 patients who had not suffered trauma or undergone surgery. Those with a history of uncomplicated inflammatory disease were included, but those with symptoms of vertigo, sensorineural hearing loss, or facial nerve palsy were excluded. Three radiologists determined the detectability and location of canals for the labyrinthine segment of the facial, superior vestibular and cochlear nerve, and the saccular branch and posterior ampullary nerve of the inferior vestibular nerve. Five bony canals in the fundus of the internal auditory canal were identified as nerve canals. Four canals were identified on axial CT images in 100% of cases; the so-called singular canal was identified in only 68%. On coronal CT images, canals for the labyrinthine segment of the facial and superior vestibular nerve were seen in 100% of cases, but those for the cochlear nerve, the saccular branch of the inferior vestibular nerve, and the singular canal were seen in 90.1%, 87.4% and 78% of cases, respectiveIy. In all detectable cases, the canal for the labyrinthine segment of the facial nerve was revealed as one which traversed anterolateralIy, from the anterosuperior portion of the fundus of the internal auditory canal. The canal for the cochlear nerve was located just below that for the labyrinthine segment of the facial nerve, while that canal for the superior vestibular nerve was seen at the posterior aspect of these two canals. The canal for the saccular branch of the inferior vestibular nerve was located just below the canal for the superior vestibular nerve, and that for the posterior ampullary nerve, the so-called singular canal, ran laterally or posteolateralIy from the posteroinferior aspect of

  4. Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

    2001-12-01

    To identify and evaluate the normal anatomy of nerve canals in the fundus of the internal auditory canal which can be visualized on high-resolution temporal bone CT. We retrospectively reviewed high-resolution (1 mm thickness and interval contiguous scan) temporal bone CT images of 253 ears in 150 patients who had not suffered trauma or undergone surgery. Those with a history of uncomplicated inflammatory disease were included, but those with symptoms of vertigo, sensorineural hearing loss, or facial nerve palsy were excluded. Three radiologists determined the detectability and location of canals for the labyrinthine segment of the facial, superior vestibular and cochlear nerve, and the saccular branch and posterior ampullary nerve of the inferior vestibular nerve. Five bony canals in the fundus of the internal auditory canal were identified as nerve canals. Four canals were identified on axial CT images in 100% of cases; the so-called singular canal was identified in only 68%. On coronal CT images, canals for the labyrinthine segment of the facial and superior vestibular nerve were seen in 100% of cases, but those for the cochlear nerve, the saccular branch of the inferior vestibular nerve, and the singular canal were seen in 90.1%, 87.4% and 78% of cases, respectiveIy. In all detectable cases, the canal for the labyrinthine segment of the facial nerve was revealed as one which traversed anterolateralIy, from the anterosuperior portion of the fundus of the internal auditory canal. The canal for the cochlear nerve was located just below that for the labyrinthine segment of the facial nerve, while that canal for the superior vestibular nerve was seen at the posterior aspect of these two canals. The canal for the saccular branch of the inferior vestibular nerve was located just below the canal for the superior vestibular nerve, and that for the posterior ampullary nerve, the so-called singular canal, ran laterally or posteolateralIy from the posteroinferior aspect of

  5. Sliding pressure control valve for pneumatic hammer drill

    Science.gov (United States)

    Polsky, Yarom [Albuquerque, NM

    2011-08-30

    A pneumatic device control apparatus and method comprising a ported valve slidably fitted over a feed tube of the pneumatic device, and using a compliant biasing device to constrain motion of the valve to provide asymmetric timing for extended pressurization of a power chamber and reduced pressurization of a return chamber of the pneumatic device. The pneumatic device can be a pneumatic hammer drill.

  6. The usefulness of MR imaging of the temporal bone in the evaluation of patients with facial and audiovestibular dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Uk; Kim, Hyung Jin; Cho, Young Kuk; Lim, Myung Kwan; Kim, Won Hong; Suh, Chang Hae; Lee, Seung Chul [Inha University College of Medicine, Incheon (Korea, Republic of)

    2002-01-01

    To evaluate the clinical utility of MR imaging of the temporal bone in patients with facial and audiovestibular dysfunction with particular emphasis on the importance of contrast enhancement. We retrospectively reviewed the MR images of 179 patients [72 men, 107 women; average age, 44 (range, 1-77) years] who presented with peripheral facial palsy (n=15), audiometrically proven sensorineural hearing loss (n=104), vertigo (n=109), or tinnitus (n=92). Positive MR imaging findings possibly responsible for the patients' clinical manifestations were categorized according to the anatomic sites and presumed etiologies of the lesions. We also assessed the utility of contrast-enhanced MR imaging by analyzing its contribution to the demonstration of lesions which would otherwise not have been apparent. All MR images were interpreted by two neuroradiologists, who reached their conclusions by consensus. MR images demonstrated positive findings, thought to account for the presenting symptoms, in 78 (44%) of 179 patients, including 15 (100%) of 15 with peripheral facial palsy, 43 (41%) of 104 with sensorineural hearing loss, 40 (37%) of 109 with vertigo, and 39 (42%) of 92 with tinnitus. Thirty (38%) of those 78 patients had lesions that could be confidently recognized only at contrast-enhanced MR imaging. Even though its use led to positive findings in less than half of these patients, MR imaging of the temporal bone is a useful diagnostic procedure in the evaluation of those with facial and audiovestibular dysfunction. Because it was only at contrast-enhanced MR imaging that a significant number of patients showed positive imaging findings which explained their clinical manifestations, the use of contrast material is highly recommended.

  7. Anatomy-Specific Virtual Reality Simulation in Temporal Bone Dissection: Perceived Utility and Impact on Surgeon Confidence.

    Science.gov (United States)

    Locketz, Garrett D; Lui, Justin T; Chan, Sonny; Salisbury, Kenneth; Dort, Joseph C; Youngblood, Patricia; Blevins, Nikolas H

    2017-06-01

    Objective To evaluate the effect of anatomy-specific virtual reality (VR) surgical rehearsal on surgeon confidence and temporal bone dissection performance. Study Design Prospective pre- and poststudy of a novel virtual surgical rehearsal platform. Setting Academic otolaryngology-head and neck surgery residency training programs. Subjects and Methods Sixteen otolaryngology-head and neck surgery residents from 2 North American training institutions were recruited. Surveys were administered to assess subjects' baseline confidence in performing 12 subtasks of cortical mastoidectomy with facial recess. A cadaver temporal bone was randomly assigned to each subject. Cadaver specimens were scanned with a clinical computed tomography protocol, allowing the creation of anatomy-specific models for use in a VR surgical rehearsal platform. Subjects then rehearsed a virtual mastoidectomy on data sets derived from their specimens. Surgical confidence surveys were administered again. Subjects then dissected assigned cadaver specimens, which were blindly graded with a modified Welling scale. A final survey assessed the perceived utility of rehearsal on dissection performance. Results Of 16 subjects, 14 (87.5%) reported a significant increase in overall confidence after conducting an anatomy-specific VR rehearsal. A significant correlation existed between perceived utility of rehearsal and confidence improvement. The effect of rehearsal on confidence was dependent on trainee experience and the inherent difficulty of the surgical subtask. Postrehearsal confidence correlated strongly with graded dissection performance. Subjects rated anatomy-specific rehearsal as having a moderate to high contribution to their dissection performance. Conclusion Anatomy-specific virtual rehearsal improves surgeon confidence in performing mastoid dissection, dependent on surgeon experience and task difficulty. The subjective confidence gained through rehearsal correlates positively with subsequent

  8. The usefulness of MR imaging of the temporal bone in the evaluation of patients with facial and audiovestibular dysfunction

    International Nuclear Information System (INIS)

    Park, Sang Uk; Kim, Hyung Jin; Cho, Young Kuk; Lim, Myung Kwan; Kim, Won Hong; Suh, Chang Hae; Lee, Seung Chul

    2002-01-01

    To evaluate the clinical utility of MR imaging of the temporal bone in patients with facial and audiovestibular dysfunction with particular emphasis on the importance of contrast enhancement. We retrospectively reviewed the MR images of 179 patients [72 men, 107 women; average age, 44 (range, 1-77) years] who presented with peripheral facial palsy (n=15), audiometrically proven sensorineural hearing loss (n=104), vertigo (n=109), or tinnitus (n=92). Positive MR imaging findings possibly responsible for the patients' clinical manifestations were categorized according to the anatomic sites and presumed etiologies of the lesions. We also assessed the utility of contrast-enhanced MR imaging by analyzing its contribution to the demonstration of lesions which would otherwise not have been apparent. All MR images were interpreted by two neuroradiologists, who reached their conclusions by consensus. MR images demonstrated positive findings, thought to account for the presenting symptoms, in 78 (44%) of 179 patients, including 15 (100%) of 15 with peripheral facial palsy, 43 (41%) of 104 with sensorineural hearing loss, 40 (37%) of 109 with vertigo, and 39 (42%) of 92 with tinnitus. Thirty (38%) of those 78 patients had lesions that could be confidently recognized only at contrast-enhanced MR imaging. Even though its use led to positive findings in less than half of these patients, MR imaging of the temporal bone is a useful diagnostic procedure in the evaluation of those with facial and audiovestibular dysfunction. Because it was only at contrast-enhanced MR imaging that a significant number of patients showed positive imaging findings which explained their clinical manifestations, the use of contrast material is highly recommended

  9. The usefulness of MR imaging of the temporal bone in the evaluation of patients with facial and audiovestibular dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Uk; Kim, Hyung Jin; Cho, Young Kuk; Lim, Myung Kwan; Kim, Won Hong; Suh, Chang Hae; Lee, Seung Chul [Inha University College of Medicine, Incheon (Korea, Republic of)

    2002-01-01

    To evaluate the clinical utility of MR imaging of the temporal bone in patients with facial and audiovestibular dysfunction with particular emphasis on the importance of contrast enhancement. We retrospectively reviewed the MR images of 179 patients [72 men, 107 women; average age, 44 (range, 1-77) years] who presented with peripheral facial palsy (n=15), audiometrically proven sensorineural hearing loss (n=104), vertigo (n=109), or tinnitus (n=92). Positive MR imaging findings possibly responsible for the patients' clinical manifestations were categorized according to the anatomic sites and presumed etiologies of the lesions. We also assessed the utility of contrast-enhanced MR imaging by analyzing its contribution to the demonstration of lesions which would otherwise not have been apparent. All MR images were interpreted by two neuroradiologists, who reached their conclusions by consensus. MR images demonstrated positive findings, thought to account for the presenting symptoms, in 78 (44%) of 179 patients, including 15 (100%) of 15 with peripheral facial palsy, 43 (41%) of 104 with sensorineural hearing loss, 40 (37%) of 109 with vertigo, and 39 (42%) of 92 with tinnitus. Thirty (38%) of those 78 patients had lesions that could be confidently recognized only at contrast-enhanced MR imaging. Even though its use led to positive findings in less than half of these patients, MR imaging of the temporal bone is a useful diagnostic procedure in the evaluation of those with facial and audiovestibular dysfunction. Because it was only at contrast-enhanced MR imaging that a significant number of patients showed positive imaging findings which explained their clinical manifestations, the use of contrast material is highly recommended.

  10. Pneumatic tourniquets in extremity surgery.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    Pneumatic tourniquets maintain a relatively bloodless field during extremity surgery, minimize blood loss, aid identification of vital structures, and expedite the procedure. However, they may induce an ischemia-reperfusion injury with potentially harmful local and systemic consequences. Modern pneumatic tourniquets are designed with mechanisms to regulate and maintain pressure. Routine maintenance helps ensure that these systems are working properly. The complications of tourniquet use include postoperative swelling, delay of recovery of muscle power, compression neurapraxia, wound hematoma with the potential for infection, vascular injury, tissue necrosis, and compartment syndrome. Systemic complications can also occur. The incidence of complications can be minimized by use of wider tourniquets, careful preoperative patient evaluation, and adherence to accepted principles of tourniquet use.

  11. Model for pneumatic pellet injection

    International Nuclear Information System (INIS)

    Hogan, J.T.; Milora, S.L.; Schuresko, D.D.

    1983-07-01

    A hydrodynamic code has been developed to model the performance of pneumatic pellet injection systems. The code describes one dimensional, unsteady compressible gas dynamics, including gas friction and heat transfer to the walls in a system with variable area. The mass, momentum, and energy equations are solved with an iterated Lax-Wendroff scheme with additional numerical viscosity. The code is described and comparisons with experimental data are presented

  12. A novel framework for the temporal analysis of bone mineral density in metastatic lesions using CT images of the femur

    Science.gov (United States)

    Knoop, Tom H.; Derikx, Loes C.; Verdonschot, Nico; Slump, Cornelis H.

    2015-03-01

    In the progressive stages of cancer, metastatic lesions in often develop in the femur. The accompanying pain and risk of fracture dramatically affect the quality of life of the patient. Radiotherapy is often administered as palliative treatment to relieve pain and restore the bone around the lesion. It is thought to affect the bone mineralization of the treated region, but the quantitative relation between radiation dose and femur remineralization remains unclear. A new framework for the longitudinal analysis of CT-scans of patients receiving radiotherapy is presented to investigate this relationship. The implemented framework is capable of automatic calibration of Hounsfield Units to calcium equivalent values and the estimation of a prediction interval per scan. Other features of the framework are temporal registration of femurs using elastix, transformation of arbitrary Regions Of Interests (ROI), and extraction of metrics for analysis. Build in Matlab, the modular approach aids easy adaptation to the pertinent questions in the explorative phase of the research. For validation purposes, an in-vitro model consisting of a human cadaver femur with a milled hole in the intertrochanteric region was used, representing a femur with a metastatic lesion. The hole was incrementally stacked with plates of PMMA bone cement with variable radiopaqueness. Using a Kolmogorov-Smirnov (KS) test, changes in density distribution due to an increase of the calcium concentration could be discriminated. In a 21 cm3 ROI, changes in 8% of the volume from 888 ± 57mg • ml-1 to 1000 ± 80mg • ml-1 could be statistically proven using the proposed framework. In conclusion, the newly developed framework proved to be a useful and flexible tool for the analysis of longitudinal CT data.

  13. Presbycusis: a human temporal bone study of individuals with flat audiometric patterns of hearing loss using a new method to quantify stria vascularis volume.

    Science.gov (United States)

    Nelson, Erik G; Hinojosa, Raul

    2003-10-01

    The purpose of this study was to determine the prevalence of stria vascularis atrophy in individuals with presbycusis and flat audiometric patterns of hearing loss. Individuals with presbycusis have historically been categorized by the shape of their audiograms, and flat audiometric thresholds have been reported to be associated with atrophy of the stria vascularis. Stria vascularis volume was not measured in these studies. Retrospective case review. Archival human temporal bones from individuals with presbycusis were selected on the basis of strict audiometric criteria for flat audiometric thresholds. Six temporal bones that met these criteria were identified and compared with 10 temporal bones in individuals with normal hearing. A unique quantitative method was developed to measure the stria vascularis volume in these temporal bones. The hair cell and spiral ganglion cell populations also were quantitatively evaluated. Only one of the six individuals with presbycusis and flat audiometric thresholds had significant atrophy of the stria vascularis. This individual with stria vascularis atrophy also had reduced inner hair cell, outer hair cell, and ganglion cell populations. Three of the individuals with presbycusis had spiral ganglion cell loss, three individuals had inner hair cell loss, and all six individuals had outer hair cell loss. The results of this investigation suggest that individuals with presbycusis and flat audiometric patterns of hearing loss infrequently have stria vascularis atrophy. Outer hair cell loss alone or in combination with inner hair cell or ganglion cell loss may be the cause of flat audiometric thresholds in individuals with presbycusis.

  14. Linear pneumatic motors – a comparative study

    Directory of Open Access Journals (Sweden)

    Deaconescu Tudor

    2017-01-01

    Full Text Available The paper presents a comparative study of the performance of single-acting cylinders, diaphragm cylinders and pneumatic muscles, and offers users information that allows the selection of an optimum technical solution. Such a study was necessary, in view of the numerous papers on pneumatic muscle applications found in literature, that assert the superiority of pneumatic muscles over other pneumatic linear motors in relation to quantities like dimensions, mass, developed force or energy-to-mass ratios, however without offering concrete data.

  15. Radiation exposure to the lens of the eye in temporal bone radiography

    International Nuclear Information System (INIS)

    Paix, D.

    1980-01-01

    Both the sensitivity of the eye to radiation cataract and the doses delivered to it in petrous bone examination are ill-defined. However, the following guidelines are suggested: (1) radiation cataract is unlikely to be a contraindication in patients over 50; (2) lens exposure per film when using an AP projection should be about 5m Gy; this may be reduced tenfold when tomographic movements permit the use of eye shields containing 1mm of lead; (3) projections which do not include the eyes in the direct beam should entail lens doses of 0.2m Gy or less; (4) steps should be taken to prevent the accumulated dose to the patient's lens from reaching 300m Gy per year or 15 Gy in all

  16. Skull base, orbits, temporal bone, and cranial nerves: anatomy on MR imaging.

    Science.gov (United States)

    Morani, Ajaykumar C; Ramani, Nisha S; Wesolowski, Jeffrey R

    2011-08-01

    Accurate delineation, diagnosis, and treatment planning of skull base lesions require knowledge of the complex anatomy of the skull base. Because the skull base cannot be directly evaluated, imaging is critical for the diagnosis and management of skull base diseases. Although computed tomography (CT) is excellent for outlining the bony detail, magnetic resonance (MR) imaging provides better soft tissue detail and is helpful for evaluating the adjacent meninges, brain parenchyma, and bone marrow of the skull base. Thus, CT and MR imaging are often used together for evaluating skull base lesions. This article focuses on the radiologic anatomy of the skull base pertinent to MR imaging evaluation. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Buckling Pneumatic Linear Actuators Inspired by Muscle

    OpenAIRE

    Yang, Dian; Verma, Mohit Singh; So, Ju-Hee; Mosadegh, Bobak; Keplinger, Christoph; Lee, Benjamin; Khashai, Fatemeh; Lossner, Elton Garret; Suo, Zhigang; Whitesides, George McClelland

    2016-01-01

    The mechanical features of biological muscles are difficult to reproduce completely in synthetic systems. A new class of soft pneumatic structures (vacuum-actuated muscle-inspired pneumatic structures) is described that combines actuation by negative pressure (vacuum), with cooperative buckling of beams fabricated in a slab of elastomer, to achieve motion and demonstrate many features that are similar to that of mammalian muscle.

  18. Pneumatic pellet injector for JET

    International Nuclear Information System (INIS)

    Andelfinger, C.; Buechl, K.; Jacobi, D.; Sandmann, W.; Schiedeck, J.; Schilling, H.B.; Weber, G.

    1983-07-01

    Pellet injection is a useful tool for plasma diagnostics of tokamaks. Pellets can be applied for investigation of particle, energy and impurity transport, fueling efficiency and magnetic surfaces. Design, operation and control of a single shot pneumatic pellet gun is described in detail including all supplies, the vacuum system and the diagnostics of the pellet. The arrangement of this injector in the torus hall and the interfaces to the JET system and CODAS are considered. A guide tube system for pellet injection is discussed but it will not be recommended for JET. (orig.)

  19. A Study of Gas Economizing Pneumatic Cylinder

    International Nuclear Information System (INIS)

    Li, T C; Wu, H W; Kuo, M J

    2006-01-01

    The pneumatic cylinder is the most typical actuator in the pneumatic equipment, and its mechanism is so simple that it is often used to operate point to point driving without the feedback loop in various automatic machines. But, the energy efficiency of pneumatic system is very poor compared with electrical systems and hydraulic systems. So, it is very important to discuss the energy saving for the pneumatic cylinder systems. In this thesis, we proposed three methods to apply the reduction in the air consumed for pneumatic cylinder systems. An air charge accumulator is used to absorb the exhausted compress air and a boost valve boosted the air to the higher pressure for used again. From the experiments, the direct used cylinder exhaust air may save about 40% of compress air

  20. Pneumatic automation systems in coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Shmatkov, N.A.; Kiklevich, Yu.N.

    1981-04-01

    Giprougleavtomatizatsiya, Avtomatgormash, Dongiprouglemash, VNIIGD and other plants develop 30 new pneumatic systems for mine machines and equipment control each year. The plants produce about 200 types of pneumatic systems. Major pneumatic systems for face systems, machines and equipment are reviewed: Sirena system for remote control of ANShch and AShchM face systems for steep coal seams, UPS control systems for pump stations, PAUZA control system for stowing machines, remote control system of B100-200 drilling machines, PUSK control system for coal cutter loaders with pneumatic drive (A-70, Temp), PUVSh control system for ventilation barriers activated from moving electric locomotives, PAZ control system for skip hoist loading. Specifications of the systems are given. Economic benefit produced by the pneumatic control systems are evaluated (from 1,500 to 40,000 rubles/year). Using the systems increases productivity of face machines and other machines used in black coal mines by 5 to 30%.

  1. Arrested Pneumatization of the Sphenoid Sinus on Large Field-of-View Cone Beam Computed Tomography Studies

    Directory of Open Access Journals (Sweden)

    Mehrnaz Tahmasbi-Arashlow

    2015-05-01

    Full Text Available Arrested pneumatization of the sphenoid sinus is a normal anatomical variant. The aim of this report is to define cone beam computed tomography (CBCT characteristics of arrested pneumatization of sphenoid sinus in an effort to help differentiate it from invasive or lytic skull base lesions. Two cases are presented with incidental findings. Both studies, acquired for other diagnostic purposes, demonstrated unique osseous patterns that were eventually deemed to be anatomic variations in the absence of clinical signs and symptoms although the pattern of bone loss and remodeling was diagnosed as pneumatization of the sphenoid sinus by a panel of medical and maxillofacial radiologists following contrasted advanced imaging. It is important to differentiate arrested pneumatization of the sphenoid sinus from lesions, such as arachnoid granulations, acoustic neuroma, glioma, metastatic lesions, meningioma, or chordoma, to prevent unnecessary biopsies or exploratory surgeries that would consequently reduce treatment costs and alleviate anxiety in patients.

  2. Synthesis of pneumatic controll systems

    Directory of Open Access Journals (Sweden)

    D. Nowak

    2011-04-01

    Full Text Available Currently, the basic tool for automating the production processes are the PLCs. However, in many areas application of the pneumaticcontrol systems may be more reasonable. The main factor determining choice of the control technology are costs. In the case of pneumaticsystems, the costs shall be determined by the number of elements used. Therefore, during the design works it is important to choose anappropriate method for the pneumatic control systems synthesis. The article presents the MTS method, which may be used for a discretetechnological processes modeling and PLC programming, as well as for a pneumatic control systems designing. An important element ofthe MTS method is the network of actions, which graphically presents an algorithm of the implemented process. Based on the actionnetwork and operating machine’s functional diagram, the diagram of different states is determinated, which graphically shows changes ofthe control system’s input and output signals. Analysis of the diagram of different states, makes it easy to determine a schematic equation, which shall be the basis for the control system implementation. Advantage of the MTS method is the lack of restrictions on the number of the control system’s input and output signals. The resulting solution is characterized by a minimum number of elements needed to implement the control system.

  3. Pneumatic Variable Series Elastic Actuator.

    Science.gov (United States)

    Zheng, Hao; Wu, Molei; Shen, Xiangrong

    2016-08-01

    Inspired by human motor control theory, stiffness control is highly effective in manipulation and human-interactive tasks. The implementation of stiffness control in robotic systems, however, has largely been limited to closed-loop control, and suffers from multiple issues such as limited frequency range, potential instability, and lack of contribution to energy efficiency. Variable-stiffness actuator represents a better solution, but the current designs are complex, heavy, and bulky. The approach in this paper seeks to address these issues by using pneumatic actuator as a variable series elastic actuator (VSEA), leveraging the compressibility of the working fluid. In this work, a pneumatic actuator is modeled as an elastic element with controllable stiffness and equilibrium point, both of which are functions of air masses in the two chambers. As such, for the implementation of stiffness control in a robotic system, the desired stiffness/equilibrium point can be converted to the desired chamber air masses, and a predictive pressure control approach is developed to control the timing of valve switching to obtain the desired air mass while minimizing control action. Experimental results showed that the new approach in this paper requires less expensive hardware (on-off valve instead of proportional valve), causes less control action in implementation, and provides good control performance by leveraging the inherent dynamics of the actuator.

  4. Caudal pneumaticity and pneumatic hiatuses in the sauropod dinosaurs Giraffatitan and Apatosaurus.

    Directory of Open Access Journals (Sweden)

    Mathew J Wedel

    Full Text Available Skeletal pneumaticity is found in the presacral vertebrae of most sauropod dinosaurs, but pneumaticity is much less common in the vertebrae of the tail. We describe previously unrecognized pneumatic fossae in the mid-caudal vertebrae of specimens of Giraffatitan and Apatosaurus. In both taxa, the most distal pneumatic vertebrae are separated from other pneumatic vertebrae by sequences of three to seven apneumatic vertebrae. Caudal pneumaticity is not prominent in most individuals of either of these taxa, and its unpredictable development means that it may be more widespread than previously recognised within Sauropoda and elsewhere in Saurischia. The erratic patterns of caudal pneumatization in Giraffatitan and Apatosaurus, including the pneumatic hiatuses, show that pneumatic diverticula were more broadly distributed in the bodies of the living animals than are their traces in the skeleton. Together with recently published evidence of cryptic diverticula--those that leave few or no skeletal traces--in basal sauropodomorphs and in pterosaurs, this is further evidence that pneumatic diverticula were widespread in ornithodirans, both across phylogeny and throughout anatomy.

  5. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging.

    Science.gov (United States)

    Meyer, Mathias; Haubenreisser, Holger; Raupach, Rainer; Schmidt, Bernhard; Lietzmann, Florian; Leidecker, Christianne; Allmendinger, Thomas; Flohr, Thomas; Schad, Lothar R; Schoenberg, Stefan O; Henzler, Thomas

    2015-01-01

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm(2) removes the necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. • Omitting the z-axis-filter allows a reduction in radiation dose of 50% • A smaller focal spot of 0.2 mm (2) significantly improves spatial resolution • Ultra-high-resolution temporal-bone-CT helps to gain diagnostic information of the middle/inner ear.

  6. Synthesis of Servo Pneumatic/Hydraulic Drive

    Directory of Open Access Journals (Sweden)

    K D. Efremova

    2017-01-01

    Full Text Available Servo pneumatic and / or hydraulic drives are widely used in modern engineering and process control. The efficiency of using pneumatic / hydraulic drives depends on their parameters and characteristics. To select the optimal drive parameters, various methods are used, based on finding the minimum of the target (target or criteria function.The objective of this paper was to apply one crucial criterion (target function that provides determination of optimal parameters of the pneumatic / hydraulic drive with the translational motion of the end-effector as well as its use in the synthesis of the servo pneumatic cylinder. The article shows the form of the target function representing a set of drive parameters that do not have direct relationships with each other in a dimensionless form for the pneumatic / hydraulic drive with the translational motion of the end-effector. To calculate the parameters of the servo drive close to the optimal ones, a two-criteria LPτ search was used. As criteria, were used the decisive criterion - the proposed target function, and the power developed by the actuator of the pneumatic / hydraulic drive, which were presented in a dimensionless form. It is shown that the criterion for solution optimality is the minimum distance of the selected point in the space of the normalized criteria from the origin. This point was determined. In addition to the proposed criteria, non-formalised requirements were taken into account: actual and mass-produced components of drive, in terms of which its parameters close to the optimal ones were determined, and the maximum relative error of the obtained useful power value of the servo pneumatic drive was estimated. The paper presents design features of two types of the servo pneumatic drive created, taking into account the proposed target function, implemented according to the schemes "hidden" and "spaced apart". The experimental static characteristic of the servo pneumatic drive is

  7. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging

    International Nuclear Information System (INIS)

    Meyer, Mathias; Haubenreisser, Holger; Schoenberg, Stefan O.; Henzler, Thomas; Raupach, Rainer; Schmidt, Bernhard; Leidecker, Christianne; Allmendinger, Thomas; Flohr, Thomas; Lietzmann, Florian; Schad, Lothar R.

    2015-01-01

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm 2 removesthe necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p < 0.05). Total effective dose was 63 %/39 % lower for the third generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. (orig.)

  8. Freely-available, true-color volume rendering software and cryohistology data sets for virtual exploration of the temporal bone anatomy.

    Science.gov (United States)

    Kahrs, Lüder Alexander; Labadie, Robert Frederick

    2013-01-01

    Cadaveric dissection of temporal bone anatomy is not always possible or feasible in certain educational environments. Volume rendering using CT and/or MRI helps understanding spatial relationships, but they suffer in nonrealistic depictions especially regarding color of anatomical structures. Freely available, nonstained histological data sets and software which are able to render such data sets in realistic color could overcome this limitation and be a very effective teaching tool. With recent availability of specialized public-domain software, volume rendering of true-color, histological data sets is now possible. We present both feasibility as well as step-by-step instructions to allow processing of publicly available data sets (Visible Female Human and Visible Ear) into easily navigable 3-dimensional models using free software. Example renderings are shown to demonstrate the utility of these free methods in virtual exploration of the complex anatomy of the temporal bone. After exploring the data sets, the Visible Ear appears more natural than the Visible Human. We provide directions for an easy-to-use, open-source software in conjunction with freely available histological data sets. This work facilitates self-education of spatial relationships of anatomical structures inside the human temporal bone as well as it allows exploration of surgical approaches prior to cadaveric testing and/or clinical implementation. Copyright © 2013 S. Karger AG, Basel.

  9. Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

    International Nuclear Information System (INIS)

    Hagiwara, Mari; Fatterpekar, Girish; Shaikh, Jamil A.; Fang, Yixin; Roehm, Pamela C.

    2012-01-01

    Previous studies suggest that semicircular canal dehiscences (SCDs) have a developmental origin. We hypothesized that if SCDs originate during development, incidence of radiographic SCDs in young children will be higher than in adults. Thirty-four temporal bone HRCTs of children younger than 2 years and 40 temporal bone HRCTs of patients older than 18 years were reformatted and re-evaluated for presence of SCD or canal thinning. Results were compared with indications for HRCT and clinical information. SCDs were detected in 27.3% of children younger than 2 years of age (superior, 13.8%; posterior, 20%) and in 3% of adults (P < 0.004). Of children with one radiographic dehiscence, 55.6% had multiple and 44% had bilateral SCDs on HRCT. No lateral canal SCDs were present. Thinning of bone overlying the semicircular canals was found in 44% of children younger than 2 years and 2.5% of adults (P < 0.0001). SCDs are more common on HRCTs of very young children. This supports the hypothesis that SCDs originate from discontinuation of bone deposition/maturation. However, SCDs on imaging do not necessarily correlate with canal dehiscence syndrome and should therefore be interpreted carefully. (orig.)

  10. Prevalence of radiographic semicircular canal dehiscence in very young children: an evaluation using high-resolution computed tomography of the temporal bones

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Mari; Fatterpekar, Girish [New York University School of Medicine, Department of Radiology, New York, NY (United States); Shaikh, Jamil A. [New York University School of Medicine, Department of Otolaryngology, New York, NY (United States); Fang, Yixin [New York University School of Medicine, Department of Otolaryngology, New York, NY (United States); New York University School of Medicine, Division of Biostatistics, Department of Environmental Medicine, New York, NY (United States); Roehm, Pamela C. [New York University School of Medicine, Department of Otolaryngology, New York, NY (United States); New York University School of Medicine, Department of Otolaryngology, Division of Otology/Neurotology, New York, NY (United States)

    2012-12-15

    Previous studies suggest that semicircular canal dehiscences (SCDs) have a developmental origin. We hypothesized that if SCDs originate during development, incidence of radiographic SCDs in young children will be higher than in adults. Thirty-four temporal bone HRCTs of children younger than 2 years and 40 temporal bone HRCTs of patients older than 18 years were reformatted and re-evaluated for presence of SCD or canal thinning. Results were compared with indications for HRCT and clinical information. SCDs were detected in 27.3% of children younger than 2 years of age (superior, 13.8%; posterior, 20%) and in 3% of adults (P < 0.004). Of children with one radiographic dehiscence, 55.6% had multiple and 44% had bilateral SCDs on HRCT. No lateral canal SCDs were present. Thinning of bone overlying the semicircular canals was found in 44% of children younger than 2 years and 2.5% of adults (P < 0.0001). SCDs are more common on HRCTs of very young children. This supports the hypothesis that SCDs originate from discontinuation of bone deposition/maturation. However, SCDs on imaging do not necessarily correlate with canal dehiscence syndrome and should therefore be interpreted carefully. (orig.)

  11. The Effect of Scala Tympani Morphology on Basilar Membrane Contact With a Straight Electrode Array: A Human Temporal Bone Study.

    Science.gov (United States)

    Verberne, Juul; Risi, Frank; Campbell, Luke; Chambers, Scott; O'Leary, Stephen

    2017-01-01

    Scala tympani morphology influences the insertion dynamics and intra-scalar position of straight electrode arrays. Hearing preservation is the goal of cochlear implantation with current thin straight electrode arrays. These hug the lateral wall, facilitating full, atraumatic insertions. However, most studies still report some postoperative hearing loss. This study explores the influence of scala tympani morphology on array position relative to the basilar membrane and its possible contribution to postoperative hearing loss. Twenty-six fresh-frozen human temporal bones implanted with a straight electrode array were three-dimensionally reconstructed from micro-photographic histological sections. Insertion depth and the proximity between the array and basilar membrane were recorded. Lateral wall shape was quantified as a curvature ratio. Insertion depths ranged from 233 to 470 degrees. The mean first point of contact between the array and basilar membrane was 185 degrees; arrays tended to remain in contact with the membrane after first contacting it. Eighty-nine and 93% of arrays that reached the upper basal (>240-360 degrees) and second (>360-720 degrees) turns respectively contacted the basilar membrane in these regions. Scalar wall curvature ratio decreased significantly (the wall became steeper) from the basal to second turns. This shift correlated with a reduced distance between the array and basilar membrane. Scala tympani morphology influences the insertion dynamics and intra-scalar position of a straight electrode array. In addition to gross trauma of cochlear structures, contact between the array and basilar membrane and how this impacts membrane function should be considered in hearing preservation cases.

  12. Diagnostic criteria for enlarged vestibular aqueduct (EVA) on CT of the temporal bones. Borderline cases of EVA

    International Nuclear Information System (INIS)

    Matsumoto, Mariko; Hoshino, Tomoyuki; Kikura, Mikino; Kikawada, Keiko; Kikawada, Toru

    2005-01-01

    The objective of this study was to examine measurements of the vestibular aqueduct on axial CT figures and to examine the cases with borderline EVA. The width of the vestibular aqueduct was measured in two places, the midpoint of the duct and the external aperture in the posterior cranial fossa. Criteria was as follow: Enlargement; ≥1.5 mm at the midpoint, ≥2 mm at the aperture, Borderline; 1-1.4 mm at the midpoint, 1.5-1.9 mm at the aperture. Three hundred forty-five cases with CT scans of the temporal bones taken during July 2003 to June 2004 in the secondary ENT referral center. Those patients include sensorinearal, mixed or conductive deafness, vertigo, ear infections and other ear diseases. Enlarged vestibular aqueduct was found in 10 ears with sensorineural deafness (SD) and 2 ears without SD. Borderline measurements were found in 19 ears with SD and 33 ears without SD. The enlarged midpoint measurement was not seen in the cases without SD. More than 1.5 mm of the definition for the enlargement at the midpoint of the vestibular aqueduct seemed to be appropriate in the clinical situation. The measurement at the midpoint of the duct is more reliable than at the external aperture. The conductive component in EVA Syndrome with mixed hearing loss is present only at the lower frequencies (250, 500 Hz), not at the middle and higer frequencies. Long-term follow-up of hearing should be done in the borderline cases with check-up of PDS gene anomaly if necessary. (author)

  13. Pneumatic and hydraulic microactuators: a review

    International Nuclear Information System (INIS)

    De Volder, Michaël; Reynaerts, Dominiek

    2010-01-01

    The development of MEMS actuators is rapidly evolving and continuously new progress in terms of efficiency, power and force output is reported. Pneumatic and hydraulic are an interesting class of microactuators that are easily overlooked. Despite the 20 years of research, and hundreds of publications on this topic, these actuators are only popular in microfluidic systems. In other MEMS applications, pneumatic and hydraulic actuators are rare in comparison with electrostatic, thermal or piezo-electric actuators. However, several studies have shown that hydraulic and pneumatic actuators deliver among the highest force and power densities at microscale. It is believed that this asset is particularly important in modern industrial and medical microsystems, and therefore, pneumatic and hydraulic actuators could start playing an increasingly important role. This paper shows an in-depth overview of the developments in this field ranging from the classic inflatable membrane actuators to more complex piston–cylinder and drag-based microdevices. (topical review)

  14. A survey on pneumatic muscle actuators modeling

    OpenAIRE

    Kelasidi, Eleni; Andrikopoulos, Georgios; Nikolakopoulos, George; Manesis, Stamatis

    2012-01-01

    The aim of this article is to provide a survey on the most popular modeling approaches for Pneumatic Muscle Actuators (PMAs). PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to their advantages such as high strength and small weight, while various types of PMAs with different technical characteristics have been appeared in...

  15. Dust emissions eliminated in pneumatic harvesting

    International Nuclear Information System (INIS)

    Kallio, M.

    1998-01-01

    Pneumatic harvesting is the most efficient milled peat production method in unsteady weather conditions. In good summers, the best contractors harvest more than 1 000 m 3 /ha milled peat from suitable production fields. The greatest problem of the method is caused by dust emissions, in particular in fields close to settled areas. About 15 % of Finland's present peat production is collected using pneumatic harvesters. A pneumatic harvester with smaller dust emissions has been developed by VTT Energy and Vapo Oy. The wagon is based on two-stage separation of peat. The main part of the coarser milled peat is first separated, e.g. in a settling chamber, and fine dry peat dust in correctly dimensioned side by side cyclones. The first series of pneumatic harvesters based on the new separation technology was employed in summer 1996. Besides decreasing the dust emissions the harvesting capacity of the new equipment was increased. The collection capacity of the pneumatic harvester can be made more effective by enlarging the container size, be decreasing the weight, by increasing the driving speed and by developing the suction capacity. Using lighter and durable construction materials combined with advanced design lighter and stronger pneumatic harvesters have been constructed. Nozzles and their mounting have also been developed. In the improvement of nozzles, the former studies with pneumatic simulator of VTT Energy, have been of great help. Studies with the pneumatic simulator and field conditions have been made in collaboration with Turveruukki Oy, Turvemetalli Oy, Raussin Metalli Oy and Vapo Oy, as well as VNIITP of St. Petersburg, Russia

  16. Fractional Order Models of Industrial Pneumatic Controllers

    Directory of Open Access Journals (Sweden)

    Abolhassan Razminia

    2014-01-01

    Full Text Available This paper addresses a new approach for modeling of versatile controllers in industrial automation and process control systems such as pneumatic controllers. Some fractional order dynamical models are developed for pressure and pneumatic systems with bellows-nozzle-flapper configuration. In the light of fractional calculus, a fractional order derivative-derivative (FrDD controller and integral-derivative (FrID are remodeled. Numerical simulations illustrate the application of the obtained theoretical results in simple examples.

  17. High-pressure portable pneumatic drive unit.

    Science.gov (United States)

    Hete, B F; Savage, M; Batur, C; Smith, W A; Golding, L A; Nosé, Y

    1989-12-01

    The left ventricular assist device (LVAD) of the Cleveland Clinic Foundation (CCF) is a single-chamber assist pump, driven by a high-pressure pneumatic cylinder. A low-cost, portable driver that will allow cardiac care patients, with a high-pressure pneumatic ventricle assist, more freedom of movement has been developed. The compact and light-weight configuration can provide periods of 2 h of freedom from a fixed position driver and does not use exotic technology.

  18. Pneumatic pellet injectors for TFTR and JET

    International Nuclear Information System (INIS)

    Combs, S.K.; Milora, S.L.

    1986-01-01

    This paper describes the development of pneumatic hydrogen pellet injectors for plasma fueling applications on the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET). The performance parameters of these injectors represent an extension of previous experience and include pellet sizes in the range 2-6 mm in diameter and speeds approaching 2 km/s. Design features and operating characteristics of these pneumatic injectors are presented

  19. Ground reaction force comparison of bilateral symmetry with pneumatic resistance squat device and free weights - biomed 2009.

    Science.gov (United States)

    Paulus, David C; Schilling, Brian K

    2009-01-01

    The unloading of spaceflight leads to bone and muscle atrophy, and a pneumatic resistance squat exercise countermeasure has the potential to provide optimized controllable resistance in a lightweight and compact configuration. However each end of the barbell in the proposed device is connected to a separate resistance cylinder which could lead to bilaterally asymmetric loading. Therefore, the purpose of the study is to compare the unilateral ground reaction forces (GRF) of the new squat device compared to free weights. Four previously trained men (mean +/- SD; age = 20+/-2 years, body mass = 99+/-18 kg) performed three sets of three repetitions of maximal exertion squat exercises with pneumatically controlled constant resistance and free weights each with a resistance level set to half of the body weight of each subject. Unilateral GRF data for each lifting modality at the negative to positive transition of the squat exercise was measured with a force plate under each foot. The pneumatic resistance GRF (N; mean +/- SD) was 749+/-114 on the left leg and 786+/-123 on the right leg and the free weight GRF was 786+/-114 left and 861+/-111 right resulting in a 5% difference between left and right GRF with pneumatics and 9% difference with free weights. The correlation coefficient between left and right GRF was 0.92 with pneumatics and 0.80 with free weights. Because the pneumatic device elicited more bilaterally symmetric GRF than traditional free weights, the separate resistance cylinders are an acceptable design configuration.

  20. High-resolution T1-weighted 3D real IR imaging of the temporal bone using triple-dose contrast material

    Energy Technology Data Exchange (ETDEWEB)

    Naganawa, Shinji; Koshikawa, Tokiko; Nakamura, Tatsuya; Fukatsu, Hiroshi; Ishigaki, Takeo [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, Shouwa-ku, 466-8550, Nagoya (Japan); Aoki, Ikuo [Medical System Company, Toshiba Corporation, Tokyo (Japan)

    2003-12-01

    The small structures in the temporal bone are surrounded by bone and air. The objectives of this study were (a) to compare contrast-enhanced T1-weighted images acquired by fast spin-echo-based three-dimensional real inversion recovery (3D rIR) against those acquired by gradient echo-based 3D SPGR in the visualization of the enhancement of small structures in the temporal bone, and (b) to determine whether either 3D rIR or 3D SPGR is useful for visualizing enhancement of the cochlear lymph fluid. Seven healthy men (age range 27-46 years) volunteered to participate in this study. All MR imaging was performed using a dedicated bilateral quadrature surface phased-array coil for temporal bone imaging at 1.5 T (Visart EX, Toshiba, Tokyo, Japan). The 3D rIR images (TR/TE/TI: 1800 ms/10 ms/500 ms) and flow-compensated 3D SPGR images (TR/TE/FA: 23 ms/10 ms/25 ) were obtained with a reconstructed voxel size of 0.6 x 0.7 x 0.8 mm{sup 3}. Images were acquired before and 1, 90, 180, and 270 min after the administration of triple-dose Gd-DTPA-BMA (0.3 mmol/kg). In post-contrast MR images, the degree of enhancement of the cochlear aqueduct, endolymphatic sac, subarcuate artery, geniculate ganglion of the facial nerve, and cochlear lymph fluid space was assessed by two radiologists. The degree of enhancement was scored as follows: 0 (no enhancement); 1 (slight enhancement); 2 (intermediate between 1 and 3); and 3 (enhancement similar to that of vessels). Enhancement scores for the endolymphatic sac, subarcuate artery, and geniculate ganglion were higher in 3D rIR than in 3D SPGR. Washout of enhancement in the endolymphatic sac appeared to be delayed compared with that in the subarcuate artery, suggesting that the enhancement in the endolymphatic sac may have been due in part to non-vascular tissue enhancement. Enhancement of the cochlear lymph space was not observed in any of the subjects in 3D rIR and 3D SPGR. The 3D rIR sequence may be more sensitive than the 3D SPGR sequence in

  1. Mastoid pneumatisation of the temporal bone in human in radiographic and anthropometric studies; Pneumatyzacja wyrostka sutkowatego kosci skroniowej u czlowieka w swietle badan radiologicznych i antropometrycznych

    Energy Technology Data Exchange (ETDEWEB)

    Czerwinski, F.; Badowicz, B.; Teul, I.; Zbiec, K. [Pomorska Akademia Medyczna, Szczecin (Poland)

    1993-12-31

    Correlation between the three chosen anthropometric indexes of neurocranium and the degree of mastoid pneumatization has been investigated in 100 male adult skulls. Anthropometric data of the neurocranium have been collected and the three anthropometric indexes have been counted. Radiographs of every mastoid were taken in the Schuller lateral projection. No notable correlation between the three chosen anthropometric indexes of neurocranium and the degree of mastoid pneumatization has been observed. (author). 9 refs; 3 figs.

  2. Muscle and bone follow similar temporal patterns of recovery from muscle-induced disuse due to botulinum toxin injection.

    Science.gov (United States)

    Manske, Sarah L; Boyd, Steven K; Zernicke, Ronald F

    2010-01-01

    If muscle force is a primary source for triggering bone adaptation, with disuse and reloading, bone changes should follow muscle changes. We examined the timing and magnitude of changes in muscle cross-sectional area (MCSA) and bone architecture in response to muscle inactivity following botulinum toxin (BTX) injection. We hypothesized that MCSA would return to baseline levels sooner than bone properties following BTX injection. Female BALB mice (15 weeks old) were injected with 20 muL of BTX (1 U/100 g body mass, n=18) or saline (SAL, n=18) into the posterior calf musculature of one limb. The contralateral limb (CON) served as an internal control. MCSA and bone properties were assessed at baseline, 2, 4, 8, 12, and 16 weeks post-injection using in vivo micro-CT at the tibia proximal metaphysis (bone only) and diaphysis. Muscles were dissected and weighed after sacrifice. Significant GroupxLegxTime interactions indicated that the maximal decrease in MCSA (56%), proximal metaphyseal BV/TV (38%) and proximal diaphyseal Ct.Ar (7%) occurred 4 weeks after injection. There was no delay prior to bone recovery as both muscle and bone properties began to recover after this time, but MCSA and BV/TV remained 15% and 20% lower, respectively, in the BTX-injected leg than the BTX-CON leg 16 weeks post-injection. Gastrocnemius mass (primarily fast-twitch) was 14% lower in the BTX-injected leg than the SAL-injected leg, while soleus mass (primarily slow-twitch) was 15% greater in the BTX group than the SAL group. Our finding that muscle size and bone began to recover at similar times after BTX injection was unexpected. This suggested that partial weight-bearing and/or return of slow-twitch muscle activity in the BTX leg may have been sufficient to stimulate bone recovery. Alternatively, muscle function may have recovered sooner than MCSA. Our results indicated that muscle cross-sectional area, while important, may not be the primary factor associated with bone loss and recovery

  3. Presbycusis: a human temporal bone study of individuals with downward sloping audiometric patterns of hearing loss and review of the literature.

    Science.gov (United States)

    Nelson, Erik G; Hinojosa, Raul

    2006-09-01

    The purpose of this retrospective case review was to identify patterns of cochlear element degeneration in individuals with presbycusis exhibiting downward sloping audiometric patterns of hearing loss and to correlate these findings with those reported in the literature to clarify conflicting concepts regarding the association between hearing loss and morphologic abnormalities. Archival human temporal bones from individuals with presbycusis were selected on the basis of strict audiometric criteria for downward-sloping audiometric thresholds. Twenty-one temporal bones that met these criteria were identified and compared with 10 temporal bones from individuals with normal hearing. The stria vascularis volumes, spiral ganglion cell populations, inner hair cells, and outer hair cells were quantitatively evaluated. The relationship between the severity of hearing loss and the degeneration of cochlear elements was analyzed using univariate linear regression models. Outer hair cell loss and ganglion cell loss was observed in all individuals with presbycusis. Inner hair cell loss was observed in 18 of the 21 individuals with presbycusis and stria vascularis loss was observed in 10 of the 21 individuals with presbycusis. The extent of degeneration of all four of the cochlear elements evaluated was highly associated with the severity of hearing loss based on audiometric thresholds at 8,000 Hz and the pure-tone average at 500, 1,000, and 2,000 Hz. The extent of ganglion cell degeneration was associated with the slope of the audiogram. Individuals with downward-sloping audiometric patterns of presbycusis exhibit degeneration of the stria vascularis, spiral ganglion cells, inner hair cells, and outer hair cells that is associated with the severity of hearing loss. This association has not been previously reported in studies that did not use quantitative methodologies for evaluating the cochlear elements and strict audiometric criteria for selecting cases.

  4. RNA analysis of inner ear cells from formalin fixed paraffin embedded (FFPE) archival human temporal bone section using laser microdissection--a technical report.

    Science.gov (United States)

    Kimura, Yurika; Kubo, Sachiho; Koda, Hiroko; Shigemoto, Kazuhiro; Sawabe, Motoji; Kitamura, Ken

    2013-08-01

    Molecular analysis using archival human inner ear specimens is challenging because of the anatomical complexity, long-term fixation, and decalcification. However, this method may provide great benefit for elucidation of otological diseases. Here, we extracted mRNA for RT-PCR from tissues dissected from archival FFPE human inner ears by laser microdissection. Three human temporal bones obtained at autopsy were fixed in formalin, decalcified by EDTA, and embedded in paraffin. The samples were isolated into spiral ligaments, outer hair cells, spiral ganglion cells, and stria vascularis by laser microdissection. RNA was extracted and heat-treated in 10 mM citrate buffer to remove the formalin-derived modification. To identify the sites where COCH and SLC26A5 mRNA were expressed, semi-nested RT-PCR was performed. We also examined how long COCH mRNA could be amplified by semi-nested RT-PCR in archival temporal bone. COCH was expressed in the spiral ligament and stria vascularis. However, SLC26A5 was expressed only in outer hair cells. The maximum base length of COCH mRNA amplified by RT-PCR was 98 bp in 1 case and 123 bp in 2 cases. We detected COCH and SLC26A5 mRNA in specific structures and cells of the inner ear from archival human temporal bone. Our innovative method using laser microdissection and semi-nested RT-PCR should advance future RNA study of human inner ear diseases. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Pneumatic wrench retains or discharges nuts or bolts as desired

    Science.gov (United States)

    Bouille, J. R.

    1966-01-01

    Pneumatic wrench grips, screws or unscrews, and discharges a nut or bolt as desired. The device consists of a standard pneumatic wrench modified with a special hex bolt head socket assembly and a diaphragm air cylinder.

  6. [Study of the degree of pneumatization of the viscerocranium in man and pongidae].

    Science.gov (United States)

    Koppe, T; Schumacher, K U

    1992-12-01

    The volumes of the paranasal sinuses of 41 adult skulls of humans, gorillas, chimpanzees and orangutans, were examined with use of a Computertomograph type SOMATOM DR. The percentage distribution of the volumes of the different paranasal sinuses showed that the maxillary sinus always had the greatest volume. The maxillary sinus of the humans showed the smallest volume percentage in comparison with the pongids. The typical differences between humans and pongids were observed in the ethmoidal cells and the sphenoidal sinus. The ethmoidal cells of the gorilla and the orangutan have to be defined as rudimentary. Those of the humans come to more than 20% of the total volume of the paranasal sinuses of all hominoids. Differing from the humans, the sphenoidal sinus of the pongids pneumatizes almost the whole sphenoid bone. This volume percentage of the pongids is twice as high as that of the humans. In addition, an index was calculated from the volume of the facial skeleton volume and the total volume of the paranasal sinuses and defined as the degree of pneumatization. We found that the gorilla has the highest degree of pneumatization followed by the chimpanzee, the orangutan, and the humans. The lowest degree of pneumatization of the humans may be related to the reduction of the jaws.

  7. 21 CFR 882.4370 - Pneumatic cranial drill motor.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pneumatic cranial drill motor. 882.4370 Section 882.4370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... drill motor. (a) Identification. A pneumatic cranial drill motor is a pneumatically operated power...

  8. Right-to-left-shunt detected by c-TCD using the orbital window in comparison with temporal bone windows.

    Science.gov (United States)

    Kobayashi, Kazuto; Kimura, Kazumi; Iguchi, Yasuyuki; Sakai, Kenichirou; Aoki, Junya; Iwanaga, Takeshi; Shibazaki, Kensaku

    2012-01-01

    There have been some reports on right-to-left shunt as a cause of cryptogenic stroke. Although contrast transcranial Doppler (c-TCD) can detect RLS, an insufficient temporal window has occasionally restricted its applicability. Thus, we compared the rates of detecting RLS among temporal windows for the middle cerebral arteries (MCAs) and the orbital window for the internal carotid artery (ICA) on c-TCD. We used c-TCD to detect RLS in patients with suspected ischemic stroke. We enrolled patients who had both sufficient bilateral temporal windows for MCAs and a right orbital window for ICA and performed c-TCD using all three windows simultaneously. We enrolled 106 consecutive patients and identified microembolic signals (MES) in 30 (28%) of them. Among these 30 patients, 15 had MES from all 3 windows. When these 30 patients were defined as being positive for RLS, the rates of detection were 67%, 73%, and 80% from the right temporal, left temporal, and right orbital windows, respectively (P= .795). The right orbital window as well as the temporal window for c-TCD could detect RLS. Insonation from the orbital window should be useful for patients who lack temporal windows. Copyright © 2010 by the American Society of Neuroimaging.

  9. Insertion characteristics and placement of the Mid-Scala electrode array in human temporal bones using detailed cone beam computed tomography.

    Science.gov (United States)

    Dietz, Aarno; Gazibegovic, Dzemal; Tervaniemi, Jyrki; Vartiainen, Veli-Matti; Löppönen, Heikki

    2016-12-01

    The aim of this study was to evaluate the insertion results and placement of the new Advanced Bionics HiFocus Mid-Scala (HFms) electrode array, inserted through the round window membrane, in eight fresh human temporal bones using cone beam computed tomography (CBCT). Pre- and post-insertion CBCT scans were registered to create a 3D reconstruction of the cochlea with the array inserted. With an image fusion technique both the bony edges of the cochlea and the electrode array in situ could accurately be determined, thus enabling to identify the exact position of the electrode array within the scala tympani. Vertical and horizontal scalar location was measured at four points along the cochlea base at an angular insertion depth of 90°, 180° and 270° and at electrode 16, the most basal electrode. Smooth insertion through the round window membrane was possible in all temporal bones. The imaging results showed that there were no dislocations from the scala tympani into the scala vestibule. The HFms electrode was positioned in the middle of the scala along the whole electrode array in three out of the eight bones and in 62 % of the individual locations measured along the base of the cochlea. In only one cochlea a close proximity of the electrode with the basilar membrane was observed, indicating possible contact with the basilar membrane. The results and assessments presented in this study appear to be highly accurate. Although a further validation including histopathology is needed, the image fusion technique described in this study represents currently the most accurate method for intracochlear electrode assessment obtainable with CBCT.

  10. Modeling and Analysis of a Novel Pneumatic Artificial Muscle and Pneumatic Arm Exoskeleton

    OpenAIRE

    Yang, Hee Doo

    2017-01-01

    The soft robotics field is developing rapidly and is poised to have a wide impact in a variety of applications. Soft robots have intrinsic compliance, offering a number of benefits as compared to traditional rigid robots. Compliance can provide compatibility with biological systems such as the human body and can provide some benefits for human safety and control. Further research into soft robots can be advanced by further development of pneumatic actuators. Pneumatic actuators are a ...

  11. Enhancing in situ bioremediation with pneumatic fracturing

    International Nuclear Information System (INIS)

    Anderson, D.B.; Peyton, B.M.; Liskowitz, J.L.; Fitzgerald, C.; Schuring, J.R.

    1994-04-01

    A major technical obstacle affecting the application of in situ bioremediation is the effective distribution of nutrients to the subsurface media. Pneumatic fracturing can increase the permeability of subsurface formations through the injection of high pressure air to create horizontal fracture planes, thus enhancing macro-scale mass-transfer processes. Pneumatic fracturing technology was demonstrated at two field sites at Tinker Air Force Base, Oklahoma City, Oklahoma. Tests were performed to increase the permeability for more effective bioventing, and evaluated the potential to increase permeability and recovery of free product in low permeability soils consisting of fine grain silts, clays, and sedimentary rock. Pneumatic fracturing significantly improved formation permeability by enhancing secondary permeability and by promoting removal of excess soil moisture from the unsaturated zone. Postfracture airflows were 500% to 1,700% higher than prefracture airflows for specific fractured intervals in the formation. This corresponds to an average prefracturing permeability of 0.017 Darcy, increasing to an average of 0.32 Darcy after fracturing. Pneumatic fracturing also increased free-product recovery rates of number 2 fuel from an average of 587 L (155 gal) per month before fracturing to 1,647 L (435 gal) per month after fracturing

  12. Endoscopic Pneumatic Dilation for Esophageal Achalasia.

    Science.gov (United States)

    Markar, Sheraz; Zaninotto, Giovanni

    2018-04-01

    Pneumatic dilation is a well-established treatment modality that has withstood the test of time. Prospective and randomized trials have shown that in expert hands, it provides results similar to a laparoscopic Heller myotomy with fundoplication. In addition, it should be considered the primary form of treatment in patients who experience recurrence of symptoms after a surgical myotomy.

  13. Pneumatic pellet injector for JT-60

    International Nuclear Information System (INIS)

    Onozuka, Masanori; Hiratsuka, Hajime; Kawasaki, Kouzo.

    1990-01-01

    The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proven that the device provides high speed pellets as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 2.3km/s at 100 bar propellant gas. (author)

  14. Pneumatic pellet injector for JT-60

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, Masanori (Mitsubishi Heavy Industries Ltd., Tokyo (Japan)); Hiratsuka, Hajime; Kawasaki, Kouzo

    1990-11-01

    The pneumatic 4-shot pellet injector has been installed and operated for JT-60 (JAERI Tokamak-60). The performance tests have proven that the device provides high speed pellets as planned. The maximum pellet velocity obtained in the hydrogen pellet tests is greater than 2.3km/s at 100 bar propellant gas. (author).

  15. Pneumatic devices in isotope technology. Pt. 1

    International Nuclear Information System (INIS)

    Egri, B.; Csoeke, A.

    1974-01-01

    A detailed survey has been given about the following pneumatic devices used in the isotope technology: working cylinders, membrane motors, valves, detectors, hydropneumatic units. The characteristics of the units of various control systems have been described in tables. (K.A.)

  16. Soft pneumatic grippers embedded with stretchable electroadhesion

    Science.gov (United States)

    Guo, J.; Elgeneidy, K.; Xiang, C.; Lohse, N.; Justham, L.; Rossiter, J.

    2018-05-01

    Current soft pneumatic grippers cannot robustly grasp flat materials and flexible objects on curved surfaces without distorting them. Current electroadhesive grippers, on the other hand, are difficult to actively deform to complex shapes to pick up free-form surfaces or objects. An easy-to-implement PneuEA gripper is proposed by the integration of an electroadhesive gripper and a two-fingered soft pneumatic gripper. The electroadhesive gripper was fabricated by segmenting a soft conductive silicon sheet into a two-part electrode design and embedding it in a soft dielectric elastomer. The two-fingered soft pneumatic gripper was manufactured using a standard soft lithography approach. This novel integration has combined the benefits of both the electroadhesive and soft pneumatic grippers. As a result, the proposed PneuEA gripper was not only able to pick-and-place flat and flexible materials such as a porous cloth but also delicate objects such as a light bulb. By combining two soft touch sensors with the electroadhesive, an intelligent and shape-adaptive PneuEA material handling system has been developed. This work is expected to widen the applications of both soft gripper and electroadhesion technologies.

  17. Improving dynamic performances of PWM-driven servo-pneumatic systems via a novel pneumatic circuit.

    Science.gov (United States)

    Taghizadeh, Mostafa; Ghaffari, Ali; Najafi, Farid

    2009-10-01

    In this paper, the effect of pneumatic circuit design on the input-output behavior of PWM-driven servo-pneumatic systems is investigated and their control performances are improved using linear controllers instead of complex and costly nonlinear ones. Generally, servo-pneumatic systems are well known for their nonlinear behavior. However, PWM-driven servo-pneumatic systems have the advantage of flexibility in the design of pneumatic circuits which affects the input-output linearity of the whole system. A simple pneumatic circuit with only one fast switching valve is designed which leads to a quasi-linear input-output relation. The quasi-linear behavior of the proposed circuit is verified both experimentally and by simulations. Closed loop position control experiments are then carried out using linear P- and PD-controllers. Since the output position is noisy and cannot be directly differentiated, a Kalman filter is designed to estimate the velocity of the cylinder. Highly improved tracking performances are obtained using these linear controllers, compared to previous works with nonlinear controllers.

  18. The temporal course of mucoperiosteal flap revascularization at guided bone regeneration treated implant sites: a pilot study

    NARCIS (Netherlands)

    Milstein, D.M.J.; Mathura, K.R.; Lindeboom, J.A.H.; Ramsoekh, D.; Lindeboom, R.; Ince, C.

    2009-01-01

    Aims: To investigate post-operative capillary density regeneration in healing mucoperiosteal flaps at guided bone regeneration-treated implant sites. Material and Methods: A non-invasive post-operative investigation was performed in 10 patients using orthogonal polarization spectral (OPS) imaging

  19. The temporal course of mucoperiosteal flap revascularization at guided bone regeneration-treated implant sites: a pilot study

    NARCIS (Netherlands)

    Milstein, Dan M. J.; Mathura, Keshen R.; Lindeboom, Jerôme A. H.; Ramsoekh, Dewkoemar; Lindeboom, Robert; Ince, Can

    2009-01-01

    P>Aims To investigate post-operative capillary density regeneration in healing mucoperiosteal flaps at guided bone regeneration-treated implant sites. Material and Methods A non-invasive post-operative investigation was performed in 10 patients using orthogonal polarization spectral (OPS) imaging

  20. Trauma dos ossos temporais e suas complicações: aspectos na tomografia computadorizada Temporal bone trauma and complications: computed tomography findings

    Directory of Open Access Journals (Sweden)

    Ana Maria Doffémond Costa

    2013-04-01

    Full Text Available A maioria das fraturas dos ossos temporais resulta de traumas cranianos bruscos, de alta energia, estando muitas vezes relacionadas a outras fraturas cranianas ou a politraumatismo. As fraturas e os deslocamentos da cadeia ossicular, na orelha média, representam umas das principais complicações das injúrias nos ossos temporais e, por isso, serão abordadas de maneira mais profunda neste artigo. Os outros tipos de injúrias englobam as fraturas labirínticas, fístula dural, paralisia facial e extensão da linha de fratura ao canal carotídeo. A tomografia computadorizada tem papel fundamental na avaliação inicial dos pacientes politraumatizados, pois é capaz de identificar injúrias em importantes estruturas que podem causar graves complicações, como perda auditiva de condução ou neurossensorial, tonturas e disfunções do equilíbrio, fístulas perilinfáticas, paralisia do nervo facial, lesões vasculares, entre outras.Most temporal bone fractures result from high-energy blunt head trauma, and are frequently related to other skull fractures or to polytrauma. Fractures and displacements of ossicular chain in the middle ear represent some of the main complications of temporal bone injury, and hence they will be more deeply approached in the present article. Other types of injuries include labyrinthine fractures, dural fistula, facial nerve paralysis and extension into the carotid canal. Computed tomography plays a fundamental role in the initial evaluation of polytrauma patients, as it can help to identify important structural injuries that may lead to severe complications such as sensorineural hearing loss, conductive hearing loss, dizziness and balance dysfunction, perilymphatic fistulas, facial nerve paralysis, vascular injury and others.

  1. Slit Tubes for Semisoft Pneumatic Actuators.

    Science.gov (United States)

    Belding, Lee; Baytekin, Bilge; Baytekin, Hasan Tarik; Rothemund, Philipp; Verma, Mohit S; Nemiroski, Alex; Sameoto, Dan; Grzybowski, Bartosz A; Whitesides, George M

    2018-03-01

    This article describes a new principle for designing soft or 'semisoft' pneumatic actuators: SLiT (for SLit-in-Tube) actuators. Inflating an elastomeric balloon, when enclosed by an external shell (a material with higher Young's modulus) containing slits of different directions and lengths, produces a variety of motions, including bending, twisting, contraction, and elongation. The requisite pressure for actuation depends on the length of the slits, and this dependence allows sequential actuation by controlling the applied pressure. Different actuators can also be controlled using external "sliders" that act as reprogrammable "on-off" switches. A pneumatic arm and a walker constructed from SLiT actuators demonstrate their ease of fabrication and the range of motions they can achieve. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Design of the Modular Pneumatic Valve Terminal

    Directory of Open Access Journals (Sweden)

    Jakub E. TAKOSOGLU

    2015-11-01

    Full Text Available The paper presents design of the modular pneumatic valve terminal, which was made on the basis of the patent application No A1 402905 „A valve for controlling fluid power drives, specially for pneumatic actuators, and the control system for fluid power drives valves”. The authors describe a method of operation of the system with double-acting valve and 5/2 (five ways and two position valve. Functions of the valve, and an example of application of the valve terminal in the production process were presented. 3D solid models of all the components of the valve were made. The paper presents a complete 3D model of the valve in various configurations. Using CAD-embedded SOLIDWORKS Flow Simulation computational fluid dynamics CFD analysis was also carried out of compressed air flow in the ways of the valve elements

  3. A pneumatic cylinder driving polyhedron mobile mechanism

    Science.gov (United States)

    Ding, Wan; Kim, Sung-Chan; Yao, Yan-An

    2012-03-01

    A novel pneumatic cylinder driving polyhedron mobile mechanism is proposed in this paper. The mechanism is comprised of 5 tetrahedrons which includes a pneumatic cylinder in each edge. It locomotes by rolling and the rolling principle refers to the center of mass (CM) of the mechanism moved out of the supporting area and let it tip over through the controlling of the motion sequence of these cylinders. Firstly, the mathematical model is built to analysis the relation between the configuration and the CM of the mechanism. Then, a binary control strategy is developed to simplify and improve the control of this mobile mechanism. After that, dynamic simulation is performed to testify the analytical validity and feasibility of the rolling gaits. At last, a prototype is fabricated to achieve the rolling successfully to demonstrate the proposed concept.

  4. Pneumatic Muscle Actuated Compliant Gripper Systems

    Directory of Open Access Journals (Sweden)

    Deaconescu Andrea

    2016-01-01

    Full Text Available The paper presents the stages of developing new, light, eco-friendly and bionic gripper systems. Gripping is achieved by means of original, self adaptive, bio-inspired systems, with a pneumatic muscle as motion generator. The method underlying the development of these new gripping systems is based on the creation of concepts by analogy, an instrument aimed at widening the inspiration horizon in designing by using models from nature.

  5. Pneumatic Muscle Actuated Compliant Gripper Systems

    OpenAIRE

    Deaconescu Andrea

    2016-01-01

    The paper presents the stages of developing new, light, eco-friendly and bionic gripper systems. Gripping is achieved by means of original, self adaptive, bio-inspired systems, with a pneumatic muscle as motion generator. The method underlying the development of these new gripping systems is based on the creation of concepts by analogy, an instrument aimed at widening the inspiration horizon in designing by using models from nature.

  6. Design evaluaion: pneumatic transport and classification

    International Nuclear Information System (INIS)

    McNair, J.M.

    1979-10-01

    This report describes the evaluation of selected design features of the cold engineering scale pneumatic transport and classification subsystems used in the development of the head-end equipment for HTGR fuel reprocessing. The report identifies areas that require further design effort and evaluation of alternatives prior to the design of the HTGR reference recycle facility (HRRF). Seven areas in the transport subsystem and three in the classification subsystem were selected for evaluation. Seventeen specific recommendations are presented for further design effort

  7. Predictors of treatment failure for pneumatic retinopexy.

    Science.gov (United States)

    Rootman, Dan B; Luu, Shelly; M Conti, Stephen; Mandell, Mark; Devenyi, Robert; Lam, Wai-Ching; Kertes, Peter J

    2013-12-01

    The purpose of this study was to define the overall anatomic success rate in pneumatic retinopexy and to identify morphologic features that may be predictive of treatment failure in pneumatic retinopexy. Prospective consecutive interventional case series of patients with new-onset primary rhegmatogenous retinal detachments treated with pneumatic retinopexy. In this interventional case series, consecutive patients with new-onset primary rhegmatogenous retinal detachments were treated with pneumatic retinopexy and followed prospectively. Morphologic data were collected on 3-colour fundus drawings. The primary outcome measure was treatment failure, defined as requirement for scleral buckle or vitrectomy within the follow-up period. Rates of failure for each morphologic feature were compared and a logistic regression model was fit. A total of 113 eyes were included in the study. Anatomic success was achieved in 69.6% of patients. Morphologic criteria including the position and number of breaks, position and extent of lattice degeneration, size of the detached area, and macular status were all found not to be significantly related to failure. In multivariate analysis, only 3 predictors, pseudophakic status (p < 0.05, odds ratio [OR] 2.9, 95% CI, 1.06-7.88), presence of retinal break greater than 1 clock-hour (p < 0.05, OR 3.41, 1.06-11.02), and presence of grade C or D proliferative vitreoretinopathy (PVR) (p < 0.01, OR 31.83, 95% CI, 3.59-282.24), gained statistical significance. Only pseudophakia, a large retinal break, and/or PVR was associated with an increased likelihood of failure. Copyright © 2013 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  8. Deep sedation during pneumatic reduction of intussusception.

    Science.gov (United States)

    Ilivitzki, Anat; Shtark, Luda Glozman; Arish, Karin; Engel, Ahuva

    2012-05-01

    Pneumatic reduction of intussusception under fluoroscopic guidance is a routine procedure. The unsedated child may resist the procedure, which may lengthen its duration and increase the radiation dose. We use deep sedation during the procedure to overcome these difficulties. The purpose of this study was to summarize our experience with deep sedation during fluoroscopic reduction of intussusception and assess the added value and complication rate of deep sedation. All children with intussusception who underwent pneumatic reduction in our hospital between January 2004 and June 2011 were included in this retrospective study. Anesthetists sedated the children using propofol. The fluoroscopic studies, ultrasound (US) studies and the childrens' charts were reviewed. One hundred thirty-one attempted reductions were performed in 119 children, of which 121 (92%) were successful and 10 (8%) failed. Two perforations (1.5%) occurred during attempted reduction. Average fluoroscopic time was 1.5 minutes. No complication to sedation was recorded. Deep sedation with propofol did not add any complication to the pneumatic reduction. The fluoroscopic time was short. The success rate of reduction was high,raising the possibility that sedation is beneficial, possibly by smooth muscle relaxation.

  9. Fractional-Order Control of Pneumatic Position Servosystems

    OpenAIRE

    Junyi, Cao; Binggang, Cao

    2011-01-01

    A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo ...

  10. Comparison of Pneumatic Dilation with Pneumatic Dilation Plus Botulinum Toxin for Treatment of Achalasia

    Directory of Open Access Journals (Sweden)

    Alireza Bakhshipour

    2010-03-01

    Full Text Available Among the therapeutic options for achalasia are pneumatic dilatation (PD, an appropriate long-term therapy, and botulinum toxin injection (BT that is a relatively short-term therapy. This study aimed to compare therapeutic effect of repetitive pneumatic dilation with a combined method (botulinum toxin injection and pneumatic dilation in a group of achalasia patients who are low responder to two initial pneumatic dilations. Thirty- four patients with documented primary achalasia that had low response to two times PD (<50% decrease in symptom score and barium height at 5 minute in timed esophagogram after 3month of late PD were randomized to receive pneumatic dilation (n=18 or botulinum toxin injection and pneumatic dilation by four weeks interval (n=16, PD and BT+PD groups respectively. Symptom scores were evaluated before and at 1, 6 and 12 months after treatment. Clinical remission was defined as a decrease in symptom score ≥ 50% of baseline. There were no significant differences between the two groups in gender, age and achalasia type. Remission rate of patients in BT-PD group in comparison with PD group were 87.5% vs. 67.1% (P = 0.7, 87.5% vs. 61.1% (P = 0.59 and 87.5% vs. 55.5% (P = 0.53 at 1, 6 and 12 months respectively .There were no major complications in either group. The mean symptom score decreased by 62.71% in the BT-PD group (P < 0.002 and 50.77% in the PD group (P < 0.01 at the end of the first year. Despite a better response rate in BT+PD group, a difference was not statistically significant. A difference may be meaningful if a large numbers of patients are included in the study.

  11. Physics-Based Pneumatic Hammer Instability Model, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Florida Turbine Technologies (FTT) proposes to conduct research necessary to develop a physics-based pneumatic hammer instability model for hydrostatic bearings...

  12. A comparison of high resolution CT scan of temporal bone and operative findings in middle ear cholesteatoma

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Tae Beom; Seong, Hun; Cheon, Mal Soon; Kim, Hack Jin; Jang, Keung Jae; Chun, Byung Hee [Dae Dong General Hospital, Busan (Korea, Republic of)

    1993-09-15

    To evaluate the value of HRCT imaging in middle ear cholesteatoma, we prospectively analysed the CT images in 28 surgically proven cases with cholesteatomas regarding main site of lesion, ossicular change, facial nerve exposure and fistula formation. The most common main site of lesion was the epitympanum (92.8%). The results of sensitivity, positive predictability, and accuracy by CT imagings were as follows: for ossicular involvement, 94.1%, 88.8%, and 86.2% in malleus, 96.0%, 88.8%, and 85.7% in incus, 81.2%, 81.2%, and 78.5% in stapes; for facial nerve exposure, 66.6%, 57.1%, and 81.2%: for fistula formation, 100%, 75.0%, and 96.4%, respectively. In conclusion, the temoral bone HRCT imaging is an accurate preoperative method in detecting main lesion site, ossicular involvement, fistula formation. Because of the low sensitivity and positive predictability in detecting facial nerve exposure, it is necessary to correlate the HRCT images with the clinical status.

  13. Pneumatic stepper motor and device comprising at least one such pneumatic stepper motor

    NARCIS (Netherlands)

    Groenhuis, Vincent; Siepel, Françoise Jeanette; Stramigioli, Stefano

    2018-01-01

    The invention relates to a pneumatic stepper motor, comprising: - a housing, said housing accommodating at least part of: - a rack or geared axle comprising a plurality of gear elements; and - two pistons, each comprising at least two teeth, said pistons being arranged to cooperate with said rack or

  14. Pneumatic Artificial Muscle Actuation and Modeling

    Science.gov (United States)

    Leephakpreeda, Thananchai; Wickramatunge, Kanchana C.

    2009-10-01

    A Pneumatic Artificial Muscle (PAM) yields a natural muscle-like actuator with a high force to weight ratio, a soft and flexible structure, and adaptable compliance for a humanoid robot, rehabilitation and prosthetic appliances to the disabled, etc. To obtain optimum design and usage, the mechanical behavior of the PAM need to be understood. In this study, observations of experimental results reveal an empirical model for relations of physical variables, contraction and air pressure within the PAM, as compared to mechanical characteristics, such as stiffness or/and pulling forces of the PAM available now in market.

  15. A pneumatic muscle hand therapy device.

    Science.gov (United States)

    Koeneman, E J; Schultz, R S; Wolf, S L; Herring, D E; Koeneman, J B

    2004-01-01

    Intensive repetitive therapy improves function and quality of life for stroke patients. Intense therapies to overcome upper extremity impairment are beneficial, however, they are expensive because, in part, they rely on individualized interaction between the patient and rehabilitation specialist. The development of a pneumatic muscle driven hand therapy device, the Mentortrade mark, reinforces the need for volitional activation of joint movement while concurrently offering knowledge of results about range of motion, muscle activity or resistance to movement. The device is well tolerated and has received favorable comments from stroke survivors, their caregivers, and therapists.

  16. Blood Sample Transportation by Pneumatic Transportation Systems

    DEFF Research Database (Denmark)

    Nybo, Mads; Lund, Merete E; Titlestad, Kjell

    2018-01-01

    BACKGROUND: Pneumatic transportation systems (PTSs) are increasingly used for transportation of blood samples to the core laboratory. Many studies have investigated the impact of these systems on different types of analyses, but to elucidate whether PTSs in general are safe for transportation...... analysis, and the hemolysis index). CONCLUSIONS: Owing to their high degree of heterogeneity, the retrieved studies were unable to supply evidence for the safety of using PTSs for blood sample transportation. In consequence, laboratories need to measure and document the actual acceleration forces...

  17. Repeating pneumatic pellet injector in JAERI

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi; Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

    1992-09-01

    A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author)

  18. Development of repeating pneumatic pellet injector

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Y.; Onozuka, M.; Shimomura, T. (Mitsubishi Heavy Industries Ltd., Kobe (Japan)) (and others)

    1990-01-01

    A repeating pneumatic pellet injector has been constructed to experiment with the technique of continuous injection for fueling fusion reactors. This device is composed of a cryogenic extruder and a gun assembly in (among others) a high-vacuum vessel, diagnostic vessels, LHe, fuel-gas and propellant-gas supply systems, control and data acquisition systems, etc. The performance tests, using hydrogen, have proved that the device provides the function of extruding frozen hydrogen ribbons at the speed of 6 mm s{sup -1}, chambering pellet at the rate of 5 Hz, and injecting pellet at the speed of 900 m s{sup -1}, as planned. (author).

  19. Development of repeating pneumatic pellet injector

    International Nuclear Information System (INIS)

    Oda, Y.; Onozuka, M.; Shimomura, T.

    1990-01-01

    A repeating pneumatic pellet injector has been constructed to experiment with the technique of continuous injection for fueling fusion reactors. This device is composed of a cryogenic extruder and a gun assembly in (among others) a high-vacuum vessel, diagnostic vessels, LHe, fuel-gas and propellant-gas supply systems, control and data acquisition systems, etc. The performance tests, using hydrogen, have proved that the device provides the function of extruding frozen hydrogen ribbons at the speed of 6 mm s -1 , chambering pellet at the rate of 5 Hz, and injecting pellet at the speed of 900 m s -1 , as planned. (author)

  20. Particle segregation in pneumatic conveying lines

    Energy Technology Data Exchange (ETDEWEB)

    McGlinchey, D.; Marjanovic, P.; Cook, S.; Jones, M.G. [Glasgow Caledonian University, Glasgow (United Kingdom). Centre for Industrial Bulk Solids Handling

    2000-07-01

    This investigation studied segregation of particles during pneumatic transport from a theoretical and experimental perspective. Dilute phase or suspension flow and dense phase (non-suspension flow) were both considered. A computer model was generated based on the conservation equations to investigate dilute phase conditions; an initial qualitative investigation of material behaviour being conveyed in dense phase was made with plastic pellets and salt as a segregating mixture in a small test rig and the results from a full scale test rig conveying two grades of coal of different size distributions are discussed. 11 refs., 9 figs., 1 tab.

  1. Robust PID Controller for a Pneumatic Actuator

    Directory of Open Access Journals (Sweden)

    Skarpetis Michael G.

    2016-01-01

    Full Text Available In this paper the position control pneumatic actuator using a robust PID controller is presented. The parameters of the PID controller are computed using a Hurwitz invariability technique enriched with a Simulated Annealing Algorithm. The nonlinear model involves uncertain parameters due to linearization of the servo valve, variations of the initial volume of the cylinder and variation of the external load. The problem is proven to be solvable and the controller parameters are chosen to provide a suboptimal solution for tracking error minimization. Simulation results are presented for the nonlinear model.

  2. Repeating pneumatic pellet injector in JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment); Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

    1992-09-01

    A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author).

  3. Mathematical Modeling of Diaphragm Pneumatic Motors

    Directory of Open Access Journals (Sweden)

    Fojtášek Kamil

    2014-03-01

    Full Text Available Pneumatic diaphragm motors belong to the group of motors with elastic working parts. This part is usually made of rubber with a textile insert and it is deformed under the pressure of a compressed air or from the external mass load. This is resulting in a final working effect. In this type of motors are in contact two different elastic environments – the compressed air and the esaltic part. These motors are mainly the low-stroke and working with relatively large forces. This paper presents mathematical modeling static properties of diaphragm motors.

  4. Variable camber wing based on pneumatic artificial muscles

    Science.gov (United States)

    Yin, Weilong; Liu, Libo; Chen, Yijin; Leng, Jinsong

    2009-07-01

    As a novel bionic actuator, pneumatic artificial muscle has high power to weight ratio. In this paper, a variable camber wing with the pneumatic artificial muscle is developed. Firstly, the experimental setup to measure the static output force of pneumatic artificial muscle is designed. The relationship between the static output force and the air pressure is investigated. Experimental result shows the static output force of pneumatic artificial muscle decreases nonlinearly with increasing contraction ratio. Secondly, the finite element model of the variable camber wing is developed. Numerical results show that the tip displacement of the trailing-edge increases linearly with increasing external load and limited with the maximum static output force of pneumatic artificial muscles. Finally, the variable camber wing model is manufactured to validate the variable camber concept. Experimental result shows that the wing camber increases with increasing air pressure and that it compare very well with the FEM result.

  5. Development of the pneumatic service robot with a hybrid type

    International Nuclear Information System (INIS)

    Choi, Cheol U; Choi, Hyeun Seok; Han, Chang Soo

    2001-01-01

    In this paper, the pneumatic service robot with a hybrid type is developed. A pneumatic has the advantage of good compliance, high payload-to-weight and payload-to-volume ratios, high speed and force capabilities. Using pneumatic actuators which have low stiffness, the service robot can guarantee safety. By suggesting a new serial-parallel hybrid type for the service robot which separates into positioning motion and orienting motion, we can achieve large workspace and high strength-to-moving-weight ratio at the same time. A sliding mode controller can be designed for tracking the desired output using the Lyapunov stability theory and structural properties of pneumatic servo systems. Through many experiments of circular trajectory, the pneumatic service robot is evaluated and verified

  6. Fractional-Order Control of Pneumatic Position Servosystems

    Directory of Open Access Journals (Sweden)

    Cao Junyi

    2011-01-01

    Full Text Available A fractional-order control strategy for pneumatic position servosystem is presented in this paper. The idea of the fractional calculus application to control theory was introduced in many works, and its advantages were proved. However, the realization of fractional-order controllers for pneumatic position servosystems has not been investigated. Based on the relationship between the pressure in cylinder and the rate of mass flow into the cylinder, the dynamic model of pneumatic position servo system is established. The fractional-order controller for pneumatic position servo and its implementation in industrial computer is designed. The experiments with fractional-order controller are carried out under various conditions, which include sine position signal with different frequency and amplitude, step position signal, and variety inertial load. The results show the effectiveness of the proposed scheme and verify their fine control performance for pneumatic position servo system.

  7. Comparison of capacity for diagnosis and visuality of auditory ossicles at different scanning angles in the computed tomography of temporal bone

    International Nuclear Information System (INIS)

    Ogura, Akio; Nakayama, Yoshiki

    1992-01-01

    Computed tomographic (CT) scanning has made significant contributions to the diagnosis and evaluation of temporal bone lesions by the thin-section, high-resolution techniques. However, these techniques involve greater radiation exposure to the lens of patients. A mean was thus sought for reducing the radiation exposure at different scanning angles such as +15 degrees and -10 degrees to the Reid's base line. Purposes of this study were to measure radiation exposure to the lens using the two tomographic planes and to compare the ability to visualize auditory ossicles and labyrinthine structures. Visual evaluation of tomographic images on auditory ossicles was made by blinded methods using four rankings by six radiologists. The statistical significance of the intergroup difference in the visualization of tomographic planes was assessed for a significance level of 0.01. Thermoluminescent dosimeter chips were placed on the cornea of tissue equivalent to the skull phantom to evaluate radiation exposure for two separate tomographic planes. As the result, tomographic plane at an angle of -10 degrees to Reid's base line allowed better visualization than the other plane for the malleus, incus, facial nerve canal, and tuba auditiva (p<0.01). Scannings at an angle of -10 degrees to Reid's base line reduced radiation exposure to approximately one-fiftieth (1/50) that with the scans at the other angle. (author)

  8. The prevalence of superior semicircular canal dehiscence in conductive and mixed hearing loss in the absence of other pathology using submillimetric temporal bone computed tomography.

    Science.gov (United States)

    Lee, Young Hen; Rivas-Rodriguez, Francisco; Song, Jae-Jun; Yang, Kyung-Sook; Mukherji, Suresh K

    2014-01-01

    The objective of this study was to assess the relationship between superior semicircular canal dehiscence (SSCD) and hearing impairment. We retrospectively compared the prevalence of SSCD in the ears classified as conductive hearing loss (CHL), mixed hearing loss (MHL), and normal hearing status using submillimetric temporal bone computed tomography (TBCT) on the basis of coronal and additional reformatted planes dedicated to SSCD. From the patients with CHL (n = 127) and MHL (n = 45), the overall prevalence of SSCD in the ears classified as CHL, MHL, and normal hearing status were 6.6%, 7.2%, and 3.0%, respectively. Furthermore, the odds ratio for SSCD in the absence of any cause of hearing loss (eg, dysfunction of the tympanic membrane or middle ear, TBCT abnormalities, otosclerosis, trauma, surgery) was 5.35 in MHL (4/27; P = 0.037, 95% confidence interval, 1.1-25.81) and 3.31 in CHL (5/61; P = 0.115, 95% confidence interval, 0.75-14.63), compared with normal hearing status. Bony covering of the SSC should be specifically evaluated in patients with hearing impairment using submillimetric TBCT.

  9. Transforming insect electromyograms into pneumatic muscle control

    Science.gov (United States)

    Rutter, Brandon; Mu, Laiyong; Ritzmann, Roy; Quinn, Roger

    2006-05-01

    Robots can serve as hardware models for testing biological hypotheses. Both for this reason and to improve the state of the art of robotics, we strive to incorporate biological principles of insect locomotion into robotic designs. Previous research has resulted in a line of robots with leg designs based on walking and climbing movements of the cockroach Blaberus discoidalis. The current version, Robot V, uses muscle-like Braided Pneumatic Actuators (BPAs). In this paper, we use recorded electromyograms (EMGs) to drive robot joint motion. A muscle activation model was developed that transforms EMGs recorded from behaving cockroaches into appropriate commands for the robot. The transform is implemented by multiplying the EMG by an input gain thus generating an input pressure signal, which is used to drive a one-way closed loop pressure controller. The actuator then can be modeled as a capacitance with input rectification. The actuator exhaust valve is given a leak rate, making the transform a leaky integrator for air pressure, which drives the output force of the actuator. We find parameters of this transform by minimizing the difference between the robot motion produced and that observed in the cockroach. Although we have not reproduced full-amplitude cockroach motion using this robot, results from evaluation on reduced-amplitude cockroach angle data strongly suggest that braided pneumatic actuators can be used as part of a physical model of a biological system.

  10. Orthopaedic Rehabilitation Device Actuated with Pneumatic Muscles

    Directory of Open Access Journals (Sweden)

    Ioana Petre

    2014-07-01

    Full Text Available Year after year recovery clinics worldwide report significant numbers of lower limb bearing joint disabilities. An effective method for the speedy rehabilitation of patients with such afflictions is Continuous Passive Motion (CPM, drawing upon a range of specific equipment. This paper presents an innovative constructive solution for such orthopaedic rehabilitation equipment, designed to ensure a swift reintegration of patients at as low a cost as possible. The absolute novelty consists in the utilization of the linear pneumatic muscle as actuator of the orthopaedic rehabilitation equipment, thus achieving a light and highly compliant construction that satisfies safety requirements related to man-machine interaction. Pneumatic muscles are bio-inspired actuation systems characterized by a passive variable compliant behaviour. This property, deployed in rehabilitation systems, enables the development of human friendly devices, which are comfortable for the patients, and capable of safe interaction. This paper presents the constructive schematic of the orthopaedic rehabilitation equipment, the structure of the actuation and positioning system, and several of its functional characteristics.

  11. Pneumatic load compensating or controlling system

    Science.gov (United States)

    Rogers, J. R. (Inventor)

    1975-01-01

    A pneumatic load compensating or controlling system for restraining a load with a predetermined force or applying a predetermined force to the load is described; it includes a source of pressurized air, a one-way pneumatic actuator operatively connected to a load, and a fluid conduit fluidically connecting the actuator with the source of pressurized air. The actuator is of the piston and cylinder type, and the end of the fluid conduit is connected to the upper or lower portion of the cylinder whereby the actuator alternatively and selectively restrains the load with a predetermined force or apply a predetermined force to the load. Pressure regulators are included within the system for variably selectively adjusting the pressurized fluid to predetermined values as desired or required; a pressure amplifier is included within the system for multiplying the pressurized values so as to achieve greater load forces. An accumulator is incorporated within the system as a failsafe operating mechanism, and visual and aural alarm devices, operatively associated with pressure detecting apparatus, readily indicate the proper or improper functioning of the system.

  12. Flowfield Analysis of a Pneumatic Solenoid Valve

    Directory of Open Access Journals (Sweden)

    Sheam-Chyun Lin

    2018-07-01

    Full Text Available Pneumatic solenoid valve has been widely used in the vehicle control systems for meeting the rapid-reaction demand triggered by the dynamic conditions encountered during the driving course of vehicle. For ensuring the safety of human being, the reliable and effective solenoid valve is in great demand to shorten the reaction time and thus becomes the topic of this research. This numerical study chooses a commercial 3/2-way solenoid valve as the reference valve for analysing its performance. At first, CFD software Fluent is adopted to simulate the flow field associated with the valve configuration. Then, the comprehensive flow visualization is implemented to identify the locations of adverse flow patterns. Accordingly, it is found that a high-pressure region exists in the zone between the nozzle exit and the top of iron core. Thereafter, the nozzle diameter and the distance between nozzle and spool are identified as the important design parameters for improving the pressure response characteristics of valve. In conclusion, this work establishes a rigorous and systematic CFD scheme to evaluate the performance of pneumatic solenoid valve.

  13. Supinator Extender (SUE): a pneumatically actuated robot for forearm/wrist rehabilitation after stroke.

    Science.gov (United States)

    Allington, James; Spencer, Steven J; Klein, Julius; Buell, Meghan; Reinkensmeyer, David J; Bobrow, James

    2011-01-01

    The robot described in this paper, SUE (Supinator Extender), adds forearm/wrist rehabilitation functionality to the UCI BONES exoskeleton robot and to the ArmeoSpring rehabilitation device. SUE is a 2-DOF serial chain that can measure and assist forearm supination-pronation and wrist flexion-extension. The large power to weight ratio of pneumatic actuators allows SUE to achieve the forces needed for rehabilitation therapy while remaining lightweight enough to be carried by BONES and ArmeoSpring. Each degree of freedom has a range of 90 degrees, and a nominal torque of 2 ft-lbs. The cylinders are mounted away from the patient's body on the lateral aspect of the arm. This is to prevent the danger of a collision and maximize the workspace of the arm robot. The rotation axis used for supination-pronation is a small bearing just below the subject's wrist. The flexion-extension motion is actuated by a cantilevered pneumatic cylinder, which allows the palm of the hand to remain open. Data are presented that demonstrate the ability of SUE to measure and cancel forearm/wrist passive tone, thereby extending the active range of motion for people with stroke.

  14. Experience and prospects of using the pneumatic designs in underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Rakhutin, V.S. [National Mining University of Ukraine, Dnipropetrovsk (Ukraine)

    1999-07-01

    The article reviews the experience of application of pneumatic designs ('flexible shells') in coal mines (pneumatic cogs and supports), ore mines (pneumatic cofferdams and partitions in filling), and in the construction of mines and underground constructions (pneumatic casings, temporary (pilot) supports). 2 refs.

  15. The effect of pneumatic dilation in management of postfundoplication dysphagia.

    Science.gov (United States)

    Sunjaya, D; Podboy, A; Blackmon, S H; Katzka, D; Halland, M

    2017-06-01

    Fundoplication surgery is a commonly performed procedure for gastro-esophageal reflux disease or hiatal hernia repair. Up to 10% of patients develop persistent postoperative dysphagia after surgery. Data on the effectiveness of pneumatic dilation for treatment are limited. The aim of this study was to evaluate clinical outcomes and identify clinical factors associated with successful response to pneumatic dilation among patients with persistent postfundoplication dysphagia (PPFD). We retrospectively evaluated patients who had undergone pneumatic dilation for PPFD between 1999 and 2016. Patients with dysphagia or achalasia prior to fundoplication were excluded. Demographic information, surgical history, severity of dysphagia, and clinical outcomes were collected. Data pertaining to esophagram, manometry, endoscopy, and pneumatic dilation were also collected. We identified 38 patients (82% female, 95% Caucasian, and median age 59 years) with PPFD who completed pneumatic dilation. The median postfundoplication dysphagia score was 2. Eleven patients had abnormal peristalsis on manometry. Seventeen patients reported response (seven complete) with an average decrease of 1 in their dysphagia score. Fifteen patients underwent reoperation due to PPFD. Hiatal hernia repair was the only factor that predicts a higher response rate to pneumatic dilation. Only one patient in our study developed complication (pneumoperitoneum) from pneumatic dilation. We found that pneumatic dilation to be a safe treatment option for PPFD with moderate efficacy. Patients who developed PPFD after a hiatal hernia repair may gain the greatest benefit after pneumatic dilation. We were not able to identify additional clinical, radiological, endoscopic, or manometric parameters that were predictive of response. © 2017 John Wiley & Sons Ltd.

  16. Osteodistrofias do Osso Temporal: Revisão dos Conceitos Atuais, Manifestações Clínicas e Opções Terapêuticas Osteodysplasia of the Temporal Bone: Up-date Concepts, Clinical Presentations and Therapeutic Options

    Directory of Open Access Journals (Sweden)

    Oswaldo Laércio M. Cruz

    Full Text Available Sob a designação de osteodistrofias do osso temporal, podemos encontrar uma série de doenças que apresentam em comum a desorganização da arquitetura ou da composição do tecido ósseo. A otospongiose é, com larga margem, a osteodistrofia mais comum nessa localização e suas alterações, repercussões clínicas e tratamentos são amplamente discutidos na literatura. Entretanto, formas menos freqüentes, como a displasia fibrosa e a osteogênese imperfeita, não são entidades raras e merecem atenção. Este artigo tem como objetivo discutir essas formas menos comuns de osteodistrofia do temporal através de uma revisão sobre os conceitos atuais dessas entidades, da apresentação de três exemplos clínicos e a discussão sobre opções de tratamento.Osteodysplasia of the temporal bone included a significant amount of osseous diseases sharing bone matrix structural and composition damage. Otospongiosis is, by far, the most frequent form of this involvement in the temporal bone. Nevertheless, fibrous dysplasia and osteogenesis imperfecta are not rare and deserve attention. In this article, the authors present a discussion about the recent concepts of those less frequent forms of osteodysplasia of temporal bone, its options of treatment, illustrated with three clinical cases.

  17. Designed pneumatic valve actuators for controlled droplet breakup and generation.

    Science.gov (United States)

    Choi, Jae-Hoon; Lee, Seung-Kon; Lim, Jong-Min; Yang, Seung-Man; Yi, Gi-Ra

    2010-02-21

    The dynamic breakup of emulsion droplets was demonstrated in double-layered microfluidic devices equipped with designed pneumatic actuators. Uniform emulsion droplets, produced by shearing at a T-junction, were broken into smaller droplets when they passed downstream through constrictions formed by a pneumatically actuated valve in the upper control layer. The valve-assisted droplet breakup was significantly affected by the shape and layout of the control valves on the emulsion flow channel. Interestingly, by actuating the pneumatic valve immediately above the T-junction, the sizes of the emulsion droplets were controlled precisely in a programmatic manner that produced arrays of uniform emulsion droplets in various sizes and dynamic patterns.

  18. Hydraulics and pneumatics a technician's and engineer's guide

    CERN Document Server

    Parr, Andrew

    1991-01-01

    Hydraulics and Pneumatics: A Technician's and Engineer's Guide provides an introduction to the components and operation of a hydraulic or pneumatic system. This book discusses the main advantages and disadvantages of pneumatic or hydraulic systems.Organized into eight chapters, this book begins with an overview of industrial prime movers. This text then examines the three different types of positive displacement pump used in hydraulic systems, namely, gear pumps, vane pumps, and piston pumps. Other chapters consider the pressure in a hydraulic system, which can be quickly and easily controlled

  19. Hydraulics and pneumatics a technician's and engineer's guide

    CERN Document Server

    Parr, Andrew

    2011-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. Such movements and manipulations are frequently accomplished by means of devices driven by liquids (hydraulics) or air (pneumatics), the subject of this book. Hydraulics and Pneumatics is written by a practicing process control engineer as a guide to the successful operation of hydraulic and pneumatic systems for all engineers and technicians working with them. Keeping mathematics and theory to a minimum, this practical guide is thorough but accessible to technicians without a

  20. On exposure to anorexia nervosa, the temporal variation in axial and appendicular skeletal development predisposes to site-specific deficits in bone size and density: a cross-sectional study.

    Science.gov (United States)

    Seeman, E; Karlsson, M K; Duan, Y

    2000-11-01

    Skeletal development is heterogeneous. Throughout growth, bone size is more maturationally advanced than the mineral being accrued within its periosteal envelope; before puberty, appendicular growth is more rapid than axial growth; during puberty, appendicular growth slows and axial growth accelerates. We studied women with differing age of onset of anorexia nervosa to determine whether this temporal heterogeneity in growth predisposed to the development of deficits in bone size and volumetric bone mineral density (vBMD), which varied by site and severity depending on the age at which anorexia nervosa occurred. Bone size and vBMD of the third lumbar vertebra and femoral neck were measured using dual-energy X-ray absorptiometry in 210 women aged 21 years (range, 12-40 years) with anorexia nervosa. Results were expressed as age-specific SDs (mean +/- SEM). Bone width depended on the age of onset of anorexia nervosa; when the onset of anorexia nervosa occurred (1) before 15 years of age, deficits in vertebral body and femoral neck width did not differ (-0.77+/-0.27 SD and -0.55+/-0.17 SD, respectively); (2) between 15 and 19 years of age, deficits in vertebral body width (-0.95+/-0.16 SD) were three times the deficits in femoral neck width (-0.28+/-0.14 SD; p anorexia nervosa. No deficit in bone width was observed at the femoral neck. Deficits in vBMD at the vertebra and femoral neck were independent of the age of onset of anorexia nervosa but increased as the duration of anorexia nervosa increased, being about 0.5 SD lower at the vertebra than femoral neck. We infer that the maturational development of a region at the time of exposure to disease, and disease duration, determine the site, magnitude, and type of trait deficit in anorexia nervosa. Bone fragility due to reduced bone size and reduced vBMD in adulthood is partly established during growth.

  1. Revisiting the Closed-Loop Pneumatic Drive Design

    Directory of Open Access Journals (Sweden)

    K D. Efremova

    2017-01-01

    Full Text Available Compressibility of air used as a working medium in pneumatic control systems raise certain difficulties in calculating dynamic characteristics of the pneumatic drive and solving problems of its regulation. These difficulties are due to a number of factors:   - flow of compressed air through the narrow working splits of distributive and throttling devices of pneumatic control;   - filling in and discharging the pneumatic actuator cavities of variable volume (piston and rod cavities of the air-cylinder under conditions of heat and mass transfer;   - simultaneous filling in and discharging a pneumatic cavity of permanent volume (receiver;   - pneumatic cylinder piston end positioning alteration under variable loading and at the moment of shutdown;A number of factors have a significant impact on the piston end positioning alteration value, namely an initial positioning of the piston at the moment of its shutdown, which determines the volume of the pneumatic cylinder cavity; a value of the permanent component of the load at the moment the piston shuts down and its change during keeping time period; transmission coefficient of the positioning component of the load; a working area of the air-cylinder piston and also an atmospheric pressure reduction, which can significantly affect the operation of control systems of a small aircraft at high altitudes.With a view to deepening the problem of calculation and design of pneumatic actuators, it is shown that the relationship between the parameters of compressed air and their changes is determined by the properties of thermodynamic processes under conditions of heat and mass transfer. In pneumatic actuators for general industrial use, the pressure of compressed air does not exceed a value equal to 1 MPa. In this case, the working medium can be regarded as an ideal gas in simplified calculations.Based on the general equation of thermodynamics, the paper considers the particular cases of a changing gas

  2. Control performance of pneumatic artificial muscle

    Science.gov (United States)

    Saga, Norihiko; Chonan, Seiji

    2007-01-01

    The robot in the future will be lightened and, in addition, the complex tasks will be done by the consumption of less energy. To achieve this, the development of an artificial muscle actuator which is as soft as a human-being becomes indispensable. At present, the artificial muscle actuator used is the McKibben type, but the heat and mechanical loss of this actuator are large because of the friction caused by the expansion and contraction of the sleeve. Therefore, we developed the artificial muscle tube where the Carbon fiber of the high intensity had been built into the silicon tube. In this report, the results of the examined the mechanical property of silicone rubber is reported, and the shrinking characteristics, response characteristics, and control performance as a pneumatic actuator are reported.

  3. A fluidic/pneumatic interface amplifier

    Science.gov (United States)

    Limbert, D. E.; Kegel, T. M.

    The development of a low cost, reliable, linear pressure amplifier to interface Laminar Proportional Amplifiers (LPA) to pneumatic controllers is presented. The amplifier consists of an LPA input stage and an output stage consisting of a venturi in series with a bellows nozzle valve. The LPA output drives the bellows nozzle valve thereby altering the flowrate through the venturi. The pressure within the venturi throat region, which is the amplifier output, changes with the flowrate. Non-linear characteristics, due to supersonic flow within the venturi, are altered through the use of feedback to the LPA input. A computer based model, to aid in optimizing the amplifier design, is developed. This model incorporates the effects of shock waves and boundary layers within the venturi. Good correspondence between the model and an experimental prototype is shown.

  4. Inductance position sensor for pneumatic cylinder

    Directory of Open Access Journals (Sweden)

    Pavel Ripka

    2018-04-01

    Full Text Available The position of the piston in pneumatic cylinder with aluminum wall can be measured by external inductance sensor without modifications of the aluminum piston and massive iron piston rod. For frequencies below 20 Hz the inductance is increasing with inserting rod due to the rod permeability. This mode has disadvantage of slow response to piston movement and also high temperature sensitivity. At the frequency of 45 Hz the inductance is position independent, as the permeability effect is compensated by the eddy current effect. At higher frequencies eddy current effects in the rod prevail, the inductance is decreasing with inserting rod. In this mode the sensitivity is smaller but the sensor response is fast and temperature stability is better. We show that FEM simulation of this sensor using measured material properties gives accurate results, which is important for the sensor optimization such as designing the winding geometry for the best linearity.

  5. Inductance position sensor for pneumatic cylinder

    Science.gov (United States)

    Ripka, Pavel; Chirtsov, Andrey; Mirzaei, Mehran; Vyhnanek, Jan

    2018-04-01

    The position of the piston in pneumatic cylinder with aluminum wall can be measured by external inductance sensor without modifications of the aluminum piston and massive iron piston rod. For frequencies below 20 Hz the inductance is increasing with inserting rod due to the rod permeability. This mode has disadvantage of slow response to piston movement and also high temperature sensitivity. At the frequency of 45 Hz the inductance is position independent, as the permeability effect is compensated by the eddy current effect. At higher frequencies eddy current effects in the rod prevail, the inductance is decreasing with inserting rod. In this mode the sensitivity is smaller but the sensor response is fast and temperature stability is better. We show that FEM simulation of this sensor using measured material properties gives accurate results, which is important for the sensor optimization such as designing the winding geometry for the best linearity.

  6. Pneumatic transport systems for TRIGA reactors

    International Nuclear Information System (INIS)

    Bolton, John A.

    1970-01-01

    Main parameters and advantages of pneumatically operated systems, primarily those operated by gas pressure are discussed. The special irradiation ends for the TRIGA reactor are described. To give some idea of the complexity of some modern systems, the author presents the large system currently operating at the National Bureau of Standards in Washington. In this system, 13 stations are located throughout the radiochemistry laboratories and three irradiation ends are located in the reactor, which is a 14-megawatt unit. The system incorporates practically every fail-safe device possible, including ball valves located on all capsule lines entering the reactor area, designed to close automatically in the event of a reactor scram, and at that time capsules within the reactor would be diverted by means of switches located on the inside of the reactor wall. The whole system is under final control of a permission control panel located in the reactor control room. Many other safety accessories of the system are described

  7. Temporal bone encephalocele and cerebrospinal fluid fistula repair utilizing the middle cranial fossa or combined mastoid-middle cranial fossa approach.

    Science.gov (United States)

    Carlson, Matthew L; Copeland, William R; Driscoll, Colin L; Link, Michael J; Haynes, David S; Thompson, Reid C; Weaver, Kyle D; Wanna, George B

    2013-11-01

    The goals of this study were to report the clinical presentation, radiographic findings, operative strategy, and outcomes among patients with temporal bone encephaloceles and cerebrospinal fluid fistulas (CSFFs) and to identify clinical variables associated with surgical outcome. A retrospective case series including all patients who underwent a middle fossa craniotomy or combined mastoid-middle cranial fossa repair of encephalocele and/or CSFF between 2000 and 2012 was accrued from 2 tertiary academic referral centers. Eighty-nine consecutive surgeries (86 patients, 59.3% women) were included. The mean age at time of surgery was 52.3 years, and the left side was affected in 53.9% of cases. The mean delay between symptom onset and diagnosis was 35.4 months, and the most common presenting symptoms were hearing loss (92.1%) and persistent ipsilateral otorrhea (73.0%). Few reported a history of intracranial infection (6.7%) or seizures (2.2%). Thirteen (14.6%) of 89 cases had a history of major head trauma, 23 (25.8%) were associated with chronic ear disease without prior operation, 17 (19.1%) occurred following tympanomastoidectomy, and 1 (1.1%) developed in a patient with a cerebral aqueduct cyst resulting in obstructive hydrocephalus. The remaining 35 cases (39.3%) were considered spontaneous. Among all patients, the mean body mass index (BMI) was 35.3 kg/m(2), and 46.4% exhibited empty sella syndrome. Patients with spontaneous lesions were statistically significantly older (p = 0.007) and were more commonly female (p = 0.048) compared with those with nonspontaneous pathology. Additionally, those with spontaneous lesions had a greater BMI than those with nonspontaneous disease (p = 0.102), although this difference did not achieve statistical significance. Thirty-two surgeries (36.0%) involved a middle fossa craniotomy alone, whereas 57 (64.0%) involved a combined mastoid-middle fossa repair. There were 7 recurrences (7.9%); 2 patients with recurrence developed

  8. Temporal growth factor release from platelet-rich plasma, trehalose lyophilized platelets, and bone marrow aspirate and their effect on tendon and ligament gene expression.

    Science.gov (United States)

    McCarrel, Taralyn; Fortier, Lisa

    2009-08-01

    Platelet-rich plasma (PRP) has generated substantial interest for tendon and ligament regeneration because of the high concentrations of growth factors in platelet alpha-granules. This study compared the temporal release of growth factors from bone marrow aspirate (BMA), PRP, and lyophilized platelet product (PP), and measured their effects on tendon and ligament gene expression. Blood and BMA were collected and processed to yield PRP and plasma. Flexor digitorum superficialis tendon (FDS) and suspensory ligament (SL) explants were cultured in 10% plasma in DMEM (control), BMA, PRP, or PP. TGF-beta1 and PDGF-BB concentrations were determined at 0, 24, and 96 h of culture using ELISA. Quantitative RT-PCR for collagen types I and III (COL1A1, COL3A1), cartilage oligomeric matrix protein (COMP), decorin, and matrix metalloproteinases-3 and 13 (MMP-3, MMP-13) was performed. TGF-beta1 and PDGF-BB concentrations were highest in PRP and PP. Growth factor quantity was unchanged in BMA, increased in PRP, and decreased in PP over 4 days. TGF-beta1 and platelet concentrations were positively correlated. Lyophilized PP and PRP resulted in increased COL1A1:COL3A1 ratio, increased COMP, and decreased MMP-13 expression. BMA resulted in decreased COMP and increased MMP-3 and MMP-13 gene expression. Platelet concentration was positively correlated with COL1A1, ratio of COL1A1:COL3A1, and COMP, and negatively correlated with COL3A1, MMP-13, and MMP-3. White blood cell concentration was positively correlated with COL3A1, MMP3, and MMP13, and negatively correlated with a ratio of COL1A1:COL3A1, COMP, and decorin. These findings support further in vivo investigation of PRP and PP for treatment of tendonitis and desmitis. Copyright 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Physics-Based Pneumatic Hammer Instability Model, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project is to develop a physics-based pneumatic hammer instability model that accurately predicts the stability of hydrostatic bearings...

  10. The Photo-Pneumatic CO2 Analyzer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We are proposing to build a new technology, the photo-pneumatic analyzer. It is small, solid-state, inexpensive, and appropriate for observations of atmospheric...

  11. Design and experiment of pneumatic EPB test platform

    Directory of Open Access Journals (Sweden)

    Jianshi GONG

    2017-02-01

    Full Text Available In order to verify the accuracy and reliability of the function and control strategy of the pneumatic electronic parking brake(EPB system, a test platform of the pneumatic EPB system is designed. The working principle of the air pressure type EPB test platform is introduced, the composition of the platform is confirmed, including air press storage module, braking module, man-machine interaction module, signal imitation module, data collection module, and fault diagnosis module, and the function of rapid charging and discharging of the pneumatic EPB system is carried out. The results show that, compared with manual control valve, the air pressure EPB braking process is more sensitive, and the test platform can meet the test requirements of the pneumatic electronic brake system.

  12. TOPICAL REVIEW: Pneumatic and hydraulic microactuators: a review

    Science.gov (United States)

    De Volder, Michaël; Reynaerts, Dominiek

    2010-04-01

    The development of MEMS actuators is rapidly evolving and continuously new progress in terms of efficiency, power and force output is reported. Pneumatic and hydraulic are an interesting class of microactuators that are easily overlooked. Despite the 20 years of research, and hundreds of publications on this topic, these actuators are only popular in microfluidic systems. In other MEMS applications, pneumatic and hydraulic actuators are rare in comparison with electrostatic, thermal or piezo-electric actuators. However, several studies have shown that hydraulic and pneumatic actuators deliver among the highest force and power densities at microscale. It is believed that this asset is particularly important in modern industrial and medical microsystems, and therefore, pneumatic and hydraulic actuators could start playing an increasingly important role. This paper shows an in-depth overview of the developments in this field ranging from the classic inflatable membrane actuators to more complex piston-cylinder and drag-based microdevices.

  13. Spot-Welding Gun With Adjustable Pneumatic Spring

    Science.gov (United States)

    Burley, Richard K.

    1990-01-01

    Proposed spot-welding gun equipped with pneumatic spring, which could be bellows or piston and cylinder, exerts force independent of position along stroke. Applies accurate controlled force to joint welded, without precise positioning at critical position within stroke.

  14. Analytical Solution to the Pneumatic Transient Rod System at ACRR

    International Nuclear Information System (INIS)

    Fehr, Brandon Michael

    2016-01-01

    The ACRR pulse is pneumatically driven by nitrogen in a system of pipes, valves and hoses up to the connection of the pneumatic system and mechanical linkages of the transient rod (TR). The main components of the TR pneumatic system are the regulator, accumulator, solenoid valve and piston-cylinder assembly. The purpose of this analysis is to analyze the flow of nitrogen through the TR pneumatic system in order to develop a motion profile of the piston during the pulse and be able to predict the pressure distributions inside both the cylinder and accumulators. The predicted pressure distributions will be validated against pressure transducer data, while the motion profile will be compared to proximity switch data. By predicting the motion of the piston, pulse timing will be determined and provided to the engineers/operators for verification. The motion profile will provide an acceleration distribution to be used in Razorback to more accurately predict reactivity insertion into the system.

  15. Analytical Solution to the Pneumatic Transient Rod System at ACRR

    Energy Technology Data Exchange (ETDEWEB)

    Fehr, Brandon Michael [Georgia Inst. of Technology, Atlanta, GA (United States)

    2016-01-08

    The ACRR pulse is pneumatically driven by nitrogen in a system of pipes, valves and hoses up to the connection of the pneumatic system and mechanical linkages of the transient rod (TR). The main components of the TR pneumatic system are the regulator, accumulator, solenoid valve and piston-cylinder assembly. The purpose of this analysis is to analyze the flow of nitrogen through the TR pneumatic system in order to develop a motion profile of the piston during the pulse and be able to predict the pressure distributions inside both the cylinder and accumulators. The predicted pressure distributions will be validated against pressure transducer data, while the motion profile will be compared to proximity switch data. By predicting the motion of the piston, pulse timing will be determined and provided to the engineers/operators for verification. The motion profile will provide an acceleration distribution to be used in Razorback to more accurately predict reactivity insertion into the system.

  16. Intelligent Switching Control of Pneumatic Artificial Muscle Manipulator

    Science.gov (United States)

    Ahn, Kyoung Kwan; Thanh, Tu Diep Cong; Ahn, Young Kong

    Problems with the control, oscillatory motion and compliance of pneumatic systems have prevented their widespread use in advanced robotics. However, their compactness, power/weight ratio, ease of maintenance and inherent safety are the factors that could potentially be exploited in sophisticated dexterous manipulator designs. These advantages have led to the development of novel actuators such as the McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle Manipulators. However, some limitations still exist, such as deterioration of the performance of transient response due to the change of the external inertia load in the pneumatic artificial muscle manipulator. To overcome this problem, switching algorithm of control parameter using learning vector quantization neural network (LVQNN) is newly proposed, which estimates the external inertia load of the pneumatic artificial muscle manipulator. The effectiveness of the proposed control algorithm is demonstrated through experiments with different external inertia loads.

  17. Second Order Sliding Mode Controller Design for Pneumatic Artificial Muscle

    OpenAIRE

    Ammar Al-Jodah; Laith Khames

    2018-01-01

    In this paper, first and second order sliding mode controllers are designed for a single link robotic arm actuated by two Pneumatic Artificial Muscles (PAMs). A new mathematical model for the arm has been developed based on the model of large scale pneumatic muscle actuator model. Uncertainty in parameters has been presented and tested for the two controllers. The simulation results of the second-order sliding mode controller proves to have a low tracking error and chattering effect as compar...

  18. Electric-Pneumatic Actuator: A New Muscle for Locomotion

    OpenAIRE

    Ahmad Sharbafi, Maziar; Shin, Hirofumi; Zhao, Guoping; Hosoda, Koh; Seyfarth, Andre

    2017-01-01

    A better understanding of how actuator design supports locomotor function may help develop novel and more functional powered assistive devices or robotic legged systems. Legged robots comprise passive parts (e.g., segments, joints and connections) which are moved in a coordinated manner by actuators. In this study, we propose a novel concept of a hybrid electric-pneumatic actuator (EPA) as an enhanced variable impedance actuator (VIA). EPA is consisted of a pneumatic artificial muscle (PAM) a...

  19. Design and experiment of pneumatic EPB test platform

    OpenAIRE

    Jianshi GONG; Tianle JIA; Dali TIAN; Hongliang WANG; Di HUANG

    2017-01-01

    In order to verify the accuracy and reliability of the function and control strategy of the pneumatic electronic parking brake(EPB) system, a test platform of the pneumatic EPB system is designed. The working principle of the air pressure type EPB test platform is introduced, the composition of the platform is confirmed, including air press storage module, braking module, man-machine interaction module, signal imitation module, data collection module, and fault diagnosis module, and the funct...

  20. Safe-geometry pneumatic nuclear fuel powder blender

    International Nuclear Information System (INIS)

    Lyon, W.L.

    1980-01-01

    A safe geometry nuclear fuel powder is claimed blender of a pneumatic type having a plurality of narrow flat-walled blending chambers or ''slab tanks'' extending radially outward from a pneumatic spouting tube having an inlet and an outlet at bottom and top, respectively, open to each slab tank or blending chamber and contained within a cylindrical cone-bottomed shell filled with neutron-absorbing material between the blending chambers

  1. Design and Experiment of 1LFQ-325 Pneumatic Reversible Plough

    OpenAIRE

    Zheng, Xuan; Chen, Xuefeng; Qin, Chaomin; Jia, Libo

    2013-01-01

    A pneumatic reversible plough is developed, which complements to the tractor of 25.7-36.8 kW. The plough adopts the cylinder as reversing mechanism between the right and left plough bodies, and the cylinder can substitute the mechanical reversing mechanism. The pneumatic turnover allows the plough to be operated easily and turned over flexibly. Field experiment results show that indicators of plough performance meet the requirements of the relevant national standards.

  2. Development of pneumatic actuator with low-wave reflection characteristics

    Science.gov (United States)

    Chang, H.; Tsung, T. T.; Jwo, C. S.; Chiang, J. C.

    2010-08-01

    This study aims at the development of a less reflective electromagnetic pneumatic actuator often used in the anechoic chamber. Because a pneumatic actuator on the market is not appropriate for use in such a chamber and a metallic one has high dielectric constant which generates reflective electromagnetic waves to influence test parameters in the chamber. The newly developed pneumatic actuator is made from low dielectric constant plastics with less reflective of electromagnetic. A turbine-type air motor is used to develop the pneumatic actuator and a employ Prony tester is used to run the brake horsepower test for the performance test of pneumatic actuator. Test results indicate that the pneumatic actuator in the minimal starting flow is 17 l/min, and it generates a brake horsepower of 48 mW; in the maximum flow is 26 l/min, it generates a brake horsepower of 108 mW. Therefore, it works with a torque between 0.24 N-m and 0.55 N-m, and such a torque will be sufficient to drive the target button.

  3. Treatments for pediatric achalasia: Heller myotomy or pneumatic dilatation?

    Science.gov (United States)

    Jung, C; Michaud, L; Mougenot, J-F; Lamblin, M-D; Philippe-Chomette, P; Cargill, G; Bonnevalle, M; Boige, N; Bellaïche, M; Viala, J; Hugot, J-P; Gottrand, F; Cezard, J-P

    2010-03-01

    The treatment of achalasia consists of reducing distal esophageal obstruction by either Heller myotomy surgery or endoscopic pneumatic dilatation. The aim of the present study was to evaluate the short- and middle-term results of these procedures in children. For technical reasons, children under six years old (n=8) were treated by surgery only, whereas patients over six years old (n=14) were treated by either Heller myotomy or pneumatic dilatation. Of the children aged under six years, 75% were symptom-free at six months and 83% at 24 months of follow-up. Of the patients aged over six years, complete remission was achieved by Heller myotomy in 44.5% vs. 55.5% by pneumatic dilatation after six months, and in 40% vs. 65%, respectively, after 24 months. Both pneumatic dilatation and Heller myotomy showed significant rates of failure. These results suggest that pneumatic dilatation may be considered a primary treatment in children over six years old. Also, where necessary, Heller myotomy and pneumatic dilatation may be used as complementary treatments.

  4. Method of sections in analytical calculations of pneumatic tires

    Science.gov (United States)

    Tarasov, V. N.; Boyarkina, I. V.

    2018-01-01

    Analytical calculations in the pneumatic tire theory are more preferable in comparison with experimental methods. The method of section of a pneumatic tire shell allows to obtain equations of intensities of internal forces in carcass elements and bead rings. Analytical dependencies of intensity of distributed forces have been obtained in tire equator points, on side walls (poles) and pneumatic tire bead rings. Along with planes in the capacity of secant surfaces cylindrical surfaces are used for the first time together with secant planes. The tire capacity equation has been obtained using the method of section, by means of which a contact body is cut off from the tire carcass along the contact perimeter by the surface which is normal to the bearing surface. It has been established that the Laplace equation for the solution of tasks of this class of pneumatic tires contains two unknown values that requires the generation of additional equations. The developed computational schemes of pneumatic tire sections and new equations allow to accelerate the pneumatic tire structure improvement process during engineering.

  5. [Morphine self-administration by rats using a pneumatic syringe].

    Science.gov (United States)

    Akiyama, Y; Takayama, S

    1988-06-01

    An apparatus for drug self-administration by rats using a pneumatic syringe was developed by Weeks. A microliter syringe operated by a pneumatic cylinder supplies an accurate volume of drug solution within one second. When coefficient of variation of infusion volume was compared among pneumatic syringe, infusion pump, and peristaltic pump, pneumatic syringe showed higher accuracy in infusion volume than the other two pumps. Since the infusion speed by a pneumatic syringe is very rapid (less than one second per infusion), the effect of infusion speed on reinforcing property of morphine was investigated. When rats self-administered 0.1, 0.3, 1.0, and 3.0 mg/kg/infusion of morphine by pneumatic syringes, the patterns of self-infusion were more stable, the number of self-infusions and the amount self-administered were larger, and a dose-response relationship was clearer in comparison with those self-infused the same doses of morphine for 5.6 seconds by infusion pumps or peristaltic pumps.

  6. Key issues in theoretical and functional pneumatic design

    Science.gov (United States)

    Xu, Z. G.; Yang, D. Y.; Liu, W. M.; Liu, T. T.

    2017-10-01

    This paper studies the energy release of the pneumatic engine in different thermodynamic processes, the isothermal process is the highest power output process, while adiabatic process is the lowest energy output process, and the energy release of the pneumatic engine is a multi-state thermodynamic process between them. Therefore heat exchanging should be increased between the pneumatic engine and the outer space, the gas expansion process in the cylinder should be as close as possible to the isothermal process. Heat exchange should be increased between the cylinder and the external spaces. Secondly, the fin structure is studied to increase the heat exchanging between the cylinder body and the outside space. The upper part has fin structures and the lower cylinder has no fin structure, this structure improved the working efficiency of pneumatic engine. Finally the cam and the hydraulic bottle of pneumatic engines are designed. Simulation and theoretical calculation are used to the analysis of the whole structure, which lay the foundation for the manufacturing and design of the pneumatic engines.

  7. A high resolution pneumatic stepping actuator for harsh reactor environments

    Science.gov (United States)

    Tippetts, Thomas B.; Evans, Paul S.; Riffle, George K.

    1993-01-01

    A reactivity control actuator for a high-power density nuclear propulsion reactor must be installed in close proximity to the reactor core. The energy input from radiation to the actuator structure could exceed hundreds of W/cc unless low-cross section, low-absorptivity materials are chosen. Also, for post-test handling and subsequent storage, materials should not be used that are activated into long half-life isotopes. Pneumatic actuators can be constructed from various reactor-compatible materials, but conventional pneumatic piston actuators generally lack the stiffness required for high resolution reactivity control unless electrical position sensors and compensated electronic control systems are used. To overcome these limitations, a pneumatic actuator is under development that positions an output shaft in response to a series of pneumatic pulses, comprising a pneumatic analog of an electrical stepping motor. The pneumatic pulses are generated remotely, beyond the strong radiation environment, and transmitted to the actuator through tubing. The mechanically simple actuator uses a nutating gear harmonic drive to convert motion of small pistons directly to high-resolution angular motion of the output shaft. The digital nature of this actuator is suitable for various reactor control algorithms but is especially compatible with the three bean salad algorithm discussed by Ball et al. (1991).

  8. Characteristic analysis and experiment of pneumatic servo valve

    International Nuclear Information System (INIS)

    Kim, Dong Soo; Lee, Won Hee; Choi, Byung Oh

    2004-01-01

    Electro-pneumatic servo valve is an electro-mechanical device which converts electric signals into a proper pneumatic flow rate or pressure. In order to improve the overall performance of pneumatic servo systems, electro-pneumatic servo valves are required, which have fast dynamic characteristics, no air leakage at a null point, and can be fabricated at a low-cost. The first objective of this research is to design and to fabricate a new electro-pneumatic servo valve which satisfies the above-mentioned requirements. In order to design the mechanism of the servo valve optimally, the flow inside the valve depending upon the position of spool was analyzed variously, and on the basis of such analysis results, the valve mechanism, which was formed by combination of the spool and the sleeve, was designed and manufactured. And a tester for conducting an overall performance test was designed and manufactured, and as a result of conducting the flow rate test, the pressure test and the frequency test on the developed pneumatic servo valve

  9. Electro-Pneumatic Control System with Hydraulically Positioning Actuator Motor

    Directory of Open Access Journals (Sweden)

    V. N. Pilgunov

    2016-01-01

    Full Text Available A compressibility of the actuating fluid of a pneumatic drive (compressed air leads to significant landing of the pneumatic cylinder piston at the time of stop and hold of the load, a constant component of which can fluctuate significantly for the holding period.There are a lot of factors, which have a significant impact on the landing value of piston. Those are: an initial position of the piston at its stop, which determines the volume of the an active area of the piston, a value of the constant load component at the time of stop and its variation for the holding period, a transfer coefficient of the position component of the load, an active area of the pneumatic cylinder piston, as well as reduction in atmospheric pressure, which can significantly affect the operation of the control systems of small aircrafts flying at high altitudes.To reduce the landing value of piston due to changing value of the constant load component for its holding period, it is proposed to use a hydraulic positioner, which comprises a hydraulic cylinder the rod of which is rigidly connected to the rod of the pneumatic cylinder through the traverse, a cross-feed valve of the hydro-cylinder cavities with discrete electro-magnetic control, and adjustable chokes.A programmable logic controller provides the hydraulic positioner control. At the moment the piston stops and the load is held the cross-feed valve overlaps the hydro-cylinder cavities thereby locking the pneumatic cylinder piston and preventing its landing. With available pneumatic cylinder-controlled signal the cross-feed valve connects the piston and rod cavities of the positioner hydro-cylinder, the pneumatic cylinder piston is released and becomes capable of moving.A numerical estimate of landing of the pneumatic cylinder piston and its positioning quality is of essential interest. For this purpose, a technique to calculate the landing of piston has been developed taking into consideration that different

  10. Dynamic contraction behaviour of pneumatic artificial muscle

    Science.gov (United States)

    Doumit, Marc D.; Pardoel, Scott

    2017-07-01

    The development of a dynamic model for the Pneumatic Artificial Muscle (PAM) is an imperative undertaking for understanding and analyzing the behaviour of the PAM as a function of time. This paper proposes a Newtonian based dynamic PAM model that includes the modeling of the muscle geometry, force, inertia, fluid dynamic, static and dynamic friction, heat transfer and valve flow while ignoring the effect of bladder elasticity. This modeling contribution allows the designer to predict, analyze and optimize PAM performance prior to its development. Thus advancing successful implementations of PAM based powered exoskeletons and medical systems. To date, most muscle dynamic properties are determined experimentally, furthermore, no analytical models that can accurately predict the muscle's dynamic behaviour are found in the literature. Most developed analytical models adequately predict the muscle force in static cases but neglect the behaviour of the system in the transient response. This could be attributed to the highly challenging task of deriving such a dynamic model given the number of system elements that need to be identified and the system's highly non-linear properties. The proposed dynamic model in this paper is successfully simulated through MATLAB programing and validated the pressure, contraction distance and muscle temperature with experimental testing that is conducted with in-house built prototype PAM's.

  11. Design of flat pneumatic artificial muscles

    Science.gov (United States)

    Wirekoh, Jackson; Park, Yong-Lae

    2017-03-01

    Pneumatic artificial muscles (PAMs) have gained wide use in the field of robotics due to their ability to generate linear forces and motions with a simple mechanism, while remaining lightweight and compact. However, PAMs are limited by their traditional cylindrical form factors, which must increase radially to improve contraction force generation. Additionally, this form factor results in overly complicated fabrication processes when embedded fibers and sensor elements are required to provide efficient actuation and control of the PAMs while minimizing the bulkiness of the overall robotic system. In order to overcome these limitations, a flat two-dimensional PAM capable of being fabricated using a simple layered manufacturing process was created. Furthermore, a theoretical model was developed using Von Karman’s formulation for large deformations and the energy methods. Experimental characterizations of two different types of PAMs, a single-cell unit and a multi-cell unit, were performed to measure the maximum contraction lengths and forces at input pressures ranging from 0 to 150 kPa. Experimental data were then used to verify the fidelity of the theoretical model.

  12. Thermo-pneumatic canning; Le gainage thermopneumatique

    Energy Technology Data Exchange (ETDEWEB)

    Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In the thermo-pneumatic canning, the fuel is enclosed in its can with a clearance that must be reduced by external heated gas pressure. The principal applications are: a) binding magnesium cans on to uranium in fuel elements of reactors cooled by CO{sub 2} under pressure, b) application of a can to a hollow bar of uranium too thin to resist the pressure of cold hydraulic canning, c) application of an aluminium can to a bar, with an initial diametrical clearance between uranium and can too great to sustain cold hydraulic canning without buckling, d) detection of major leakage in the slugs. (author) [French] Ce procede consiste a appliquer une gaine sur une barre d'uranium par pression hydrostatique d'un gaz chaud. Les principales applications sont: a) le frettage des gaines de magnesium des elements combustibles des piles refroidies au CO{sub 2} sous pression, b) le gainage d'un barreau creux qui serait ecrase a froid, c) le gainage avec un jeu initial trop fort pour etre effectue a froid sans plisser, d) la detection des fuites de cartouches. (auteur)

  13. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  14. Cranial pneumatization and auditory perceptions of the oviraptorid dinosaur Conchoraptor gracilis (Theropoda, Maniraptora) from the Late Cretaceous of Mongolia

    Science.gov (United States)

    Ramanah, D.; Raghunath, S.; Mee, D. J.; Rösgen, T.; Jacobs, P. A.

    2007-09-01

    The distribution of air-filled structures in the craniofacial and neurocranial bones of the oviraptorid ZPAL MgD-I/95, discovered at the Hermiin Tsav locality, Mongolia, is restored. Based on the complete obliteration of most of the cranial sutures, the specimen is identified as an adult individual of Conchoraptor gracilis Barsbold 1986. Except for the orbitosphenoids and epipterygoids, the preserved bones of the neurocranium are hollow. Three types of tympanic recess are present in Conchoraptor, a characteristic shared with troodontids, dromaeosaurids, and avian theropods. The contralateral middle ear cavities are interconnected by the supraencephalic pathway that passes through the dorsal tympanic recesses, the posterodorsal prootic sinuses and the parietal sinus. The spatial arrangements of the middle ear cavity and a derived neurocranial pneumatic system in Conchoraptor indicate enhancements of acoustic perception in the lower-frequency registers and of auditory directionality. We further speculate that this improvement of binaural hearing could be explained as an adaptation required for accurate detection of prey and/or predators under conditions of low illumination. The other potentially pneumatic structures of the Conchoraptor cranium include (1) recessus-like irregularities on the dorsal surface of the nasal and frontal bones (a putative oviraptorid synapomorphy; pos); (2) a subotic recess; (3) a sub-condylar recess; and (4) a posterior condylar recess (pos).

  15. A novel form of postcranial skeletal pneumaticity in a sauropod dinosaur: Implications for the paleobiology of Rebbachisauridae

    Directory of Open Access Journals (Sweden)

    Lucio M. Ibiricu

    2017-06-01

    Full Text Available In dinosaurs and other archosaurs, the presence of foramina connected with internal chambers in axial and appendicular bones is regarded as a robust indicator of postcranial skeletal pneumaticity (PSP. Here we analyze PSP and its paleobiological implications in rebbachisaurid diplodocoid sauropod dinosaurs based primarily on the dorsal vertebrae of Katepensaurus goicoecheai, a rebbachisaurid from the Cenomanian–Turonian (Upper Cretaceous Bajo Barreal Formation of Patagonia, Argentina. We document a complex of interconnected pneumatic foramina and internal chambers within the dorsal vertebral transverse processes of Katepensaurus. Collectively, these structures constitute a form of PSP that has not previously been observed in sauropods, though it is closely comparable to morphologies seen in selected birds and non-avian theropods. Parts of the skeletons of Katepensaurus and other rebbachisaurid taxa such as Amazonsaurus maranhensis and Tataouinea hannibalis exhibit an elevated degree of pneumaticity relative to the conditions in many other sauropods. We interpret this extensive PSP as an adaptation for lowering the density of the skeleton, and tentatively propose that this reduced skeletal density may also have decreased the muscle energy required to move the body and the heat generated in so doing. Given that several rebbachisaurids inhabited tropical to subtropical paleolatitudes during the extreme warmth of the mid-Cretaceous, increased PSP may have better enabled these sauropods to cope with extraordinarily high temperatures. Extensive skeletal pneumaticity may have been an important innovation in Rebbachisauridae, and perhaps also in saltasaurine titanosaurs, which evolved an even greater degree of PSP. This may in turn have contributed to the evolutionary success of rebbachisaurids, which were the only diplodocoids to survive into the Late Cretaceous.

  16. Achalasia: pneumatic Dilation. Experience in a reference hospital

    International Nuclear Information System (INIS)

    Garzon, Martin; Farfan, Yezid; Molano, Juan; Rey, Mario; Martinez, Julian; Marulanda, Juan

    2005-01-01

    Chalasia has an incidence of 1:100.000. The therapy for achalasia, focus on reducing the pressure gradient across the LES, which can be achieved by forceful pneumatic dilation of the gastroesophageal junction, surgical myotomy or by pharmacological agents, injected endoscopically or taken orally. Pneumatic balloon dilation is regarded as the first-Line treatment, with an initial success rate of 85% to 90%. The objective of this study is to show our experience with pneumatic balloon dilation in the patients with diagnosis of achalasia from the hospital La Samaritana during a period from February 2002 to February 2005. Patients diagnosed with achalasia from the department of gastroenterology and endoscopy of the Hospital La Samaritana during period of February 2002 to February 2005 was included. Procedures were made in fluoroscopy room. The patients received intravenous sedation and analgesia. We used a Regiflex balloon, 3.5 cm diameter. Balloons were inflated with saline water and water-soluble contrast during one minute. We diagnosed 19 patients with achalasia during period from February 2002 to February 2005, 14 were females and 5 males (26%); we made pneumatic dilation in 11 patients (60%), 9 were females (82%) with mean age 38.9 years (ranged from 16 to 13 years). Three patients (21%) underwent once pneumatic dilation and the rest (8 patients) underwent twice (73%). We don't report any perforation. So far we have followed the patients ambulatory during period from 6 months to 2 years. We find recurrence one year after of the pneumatic dilation in a female patient 22 years old (9%). The pneumatic dilation as cost-effective therapy, with a good initial success, but in the longer the follow-up lower the success rate and low morbidity (4). We suggest making only two pneumatic dilations. Today, there isn't consensus on the optimal endoscopic dilation technique and we believe that the sedation must be included in this procedure. In the future, we need more comparative

  17. A new pneumatic suspension system with independent stiffness and ride height tuning capabilities

    Science.gov (United States)

    Yin, Zhihong; Khajepour, Amir; Cao, Dongpu; Ebrahimi, Babak; Guo, Konghui

    2012-12-01

    This paper introduces a new pneumatic spring for vehicle suspension systems, allowing independent tuning of stiffness and ride height according to different vehicle operating conditions and driver preferences. The proposed pneumatic spring comprises a double-acting pneumatic cylinder, two accumulators and a tuning subsystem. This paper presents a detailed description of the pneumatic spring and its working principle. The mathematical model is established based on principles of thermo and fluid dynamics. An experimental setup has been designed and fabricated for testing and evaluating the proposed pneumatic spring. The analytical and experimental results confirm the capability of the new pneumatic spring system for independent tuning of stiffness and ride height. The mathematical model is verified and the capabilities of the pneumatic spring are further proved. It is concluded that this new pneumatic spring provides a more flexible suspension design alternative for meeting various conflicting suspension requirements for ride comfort and performance.

  18. Application of in vivo micro-computed tomography in the temporal characterisation of subchondral bone architecture in a rat model of low-dose monosodium iodoacetate-induced osteoarthritis

    Science.gov (United States)

    2011-01-01

    Introduction Osteoarthritis (OA) is a complex, multifactorial joint disease affecting both the cartilage and the subchondral bone. Animal models of OA aid in the understanding of the pathogenesis of OA and testing suitable drugs for OA treatment. In this study we characterized the temporal changes in the tibial subchondral bone architecture in a rat model of low-dose monosodium iodoacetate (MIA)-induced OA using in vivo micro-computed tomography (CT). Methods Male Wistar rats received a single intra-articular injection of low-dose MIA (0.2 mg) in the right knee joint and sterile saline in the left knee joint. The animals were scanned in vivo by micro-CT at two, six, and ten weeks post-injection, analogous to early, intermediate, and advanced stages of OA, to assess architectural changes in the tibial subchondral bone. The articular cartilage changes in the tibiae were assessed macroscopically and histologically at ten weeks post-injection. Results Interestingly, tibiae of the MIA-injected knees showed significant bone loss at two weeks, followed by increased trabecular thickness and separation at six and ten weeks. The trabecular number was decreased at all time points compared to control tibiae. The tibial subchondral plate thickness of the MIA-injected knee was increased at two and six weeks and the plate porosity was increased at all time points compared to control. At ten weeks, histology revealed loss of proteoglycans, chondrocyte necrosis, chondrocyte clusters, cartilage fibrillation, and delamination in the MIA-injected tibiae, whereas the control tibiae showed no changes. Micro-CT images and histology showed the presence of subchondral bone sclerosis, cysts, and osteophytes. Conclusions These findings demonstrate that the low-dose MIA rat model closely mimics the pathological features of progressive human OA. The low-dose MIA rat model is therefore suitable to study the effect of therapeutic drugs on cartilage and bone in a non-trauma model of OA. In vivo

  19. Modeling the dynamic characteristics of pneumatic muscle.

    Science.gov (United States)

    Reynolds, D B; Repperger, D W; Phillips, C A; Bandry, G

    2003-03-01

    A pneumatic muscle (PM) system was studied to determine whether a three-element model could describe its dynamics. As far as the authors are aware, this model has not been used to describe the dynamics of PM. A new phenomenological model consists of a contractile (force-generating) element, spring element, and damping element in parallel. The PM system was investigated using an apparatus that allowed precise and accurate actuation pressure (P) control by a linear servo-valve. Length change of the PM was measured by a linear potentiometer. Spring and damping element functions of P were determined by a static perturbation method at several constant P values. These results indicate that at constant P, PM behaves as a spring and damper in parallel. The contractile element function of P was determined by the response to a step input in P, using values of spring and damping elements from the perturbation study. The study showed that the resulting coefficient functions of the three-element model describe the dynamic response to the step input of P accurately, indicating that the static perturbation results can be applied to the dynamic case. This model is further validated by accurately predicting the contraction response to a triangular P waveform. All three elements have pressure-dependent coefficients for pressure P in the range 207 < or = P < or = 621 kPa (30 < or = P < or = 90 psi). Studies with a step decrease in P (relaxation of the PM) indicate that the damping element coefficient is smaller during relaxation than contraction.

  20. A Pneumatic Actuated Microfluidic Beads-Trapping Device

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Guocheng; Cai, Ziliang; Wang, Jun; Wang, Wanjun; Lin, Yuehe

    2011-08-20

    The development of a polydimethylsiloxane (PDMS) microfluidic microbeads trapping device is reported in this paper. Besides fluid channels, the proposed device includes a pneumatic control chamber and a beads-trapping chamber with a filter array structure. The pneumatic flow control chamber and the beads-trapping chamber are vertically stacked and separated by a thin membrane. By adjusting the pressure in the pneumatic control chamber, the membrane can either be pushed against the filter array to set the device in trapping mode or be released to set the device in releasing mode. In this paper, a computational fluid dynamics simulation was conducted to optimize the geometry design of the filter array structure; the device fabrication was also carried out. The prototype device was tested and the preliminary experimental results showed that it can be used as a beads-trapping unit for various biochemistry and analytical chemistry applications, especially for flow injection analysis systems.

  1. An ankle-foot orthosis powered by artificial pneumatic muscles.

    Science.gov (United States)

    Ferris, Daniel P; Czerniecki, Joseph M; Hannaford, Blake

    2005-05-01

    We developed a pneumatically powered orthosis for the human ankle joint. The orthosis consisted of a carbon fiber shell, hinge joint, and two artificial pneumatic muscles. One artificial pneumatic muscle provided plantar flexion torque and the second one provided dorsiflexion torque. Computer software adjusted air pressure in each artificial muscle independently so that artificial muscle force was proportional to rectified low-pass-filtered electromyography (EMG) amplitude (i.e., proportional myoelectric control). Tibialis anterior EMG activated the artificial dorsiflexor and soleus EMG activated the artificial plantar flexor. We collected joint kinematic and artificial muscle force data as one healthy participant walked on a treadmill with the orthosis. Peak plantar flexor torque provided by the orthosis was 70 Nm, and peak dorsiflexor torque provided by the orthosis was 38 Nm. The orthosis could be useful for basic science studies on human locomotion or possibly for gait rehabilitation after neurological injury.

  2. Model analysis of mechanisms controlling pneumatic soil vapor extraction

    DEFF Research Database (Denmark)

    Høier, Camilla Kruse; Sonnenborg, Torben Obel; Jensen, Karsten Høgh

    2009-01-01

    of heterogeneous soils by enforcing large fluctuating pressure fronts through the contaminated area. Laboratory experiments have suggested that pneumatic SVE considerably improves the recovery rate from low-permeable units. We have analyzed the experimental results using a numerical code and quantified......The efficiency of traditional soil venting or soil vapor extraction (SVE) highly depends on the architecture of the subsurface because imposed advective air flow tends to bypass low-permeable contaminated areas. Pneumatic SVE is a technique developed to enhance remediation efficiency...... level the pneumatic venting technology is superior to the traditional technique, and that the method is particularly efficient in cases where large permeability contrasts exist between soil units in the subsurface....

  3. 46 CFR 108.409 - Location and spacing of tubing in pneumatic fire detection system.

    Science.gov (United States)

    2010-10-01

    ... detection system. 108.409 Section 108.409 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... and spacing of tubing in pneumatic fire detection system. (a) All tubing in a pneumatic fire detection... exposed in the space. (c) A pneumatic fire detection system must be set to activate after approximately a...

  4. Second Order Sliding Mode Controller Design for Pneumatic Artificial Muscle

    Directory of Open Access Journals (Sweden)

    Ammar Al-Jodah

    2018-01-01

    Full Text Available In this paper, first and second order sliding mode controllers are designed for a single link robotic arm actuated by two Pneumatic Artificial Muscles (PAMs. A new mathematical model for the arm has been developed based on the model of large scale pneumatic muscle actuator model. Uncertainty in parameters has been presented and tested for the two controllers. The simulation results of the second-order sliding mode controller proves to have a low tracking error and chattering effect as compared to the first order one. The verification has been done by using MATLAB and Simulink software.

  5. Nonlinear Disturbance Observer Based Robust Tracking Control of Pneumatic Muscle

    Directory of Open Access Journals (Sweden)

    Youssif Mohamed Toum Elobaid

    2014-01-01

    Full Text Available Presently pneumatic muscles (PMs are used in various applications due to their simple construction, lightweight, and high force-to-weight ratio. However, pneumatic muscles are facing various problems due to their nonlinear characteristics and various uncertainties in real applications. To cope with the uncertainties and strong nonlinearity of a PM model, a nonlinear disturbance observer (NDO is designed to estimate the lumped disturbance. Based on the disturbance observer, the tracking control of PM is studied. Stability analysis based on Lyapunov method with respect to our proposed control law is discussed. The simulation results show the validity, effectiveness, and enhancing robustness of the proposed methods.

  6. An artificial flexible robot arm based on pneumatic muscle actuators

    Directory of Open Access Journals (Sweden)

    Renn Jyh-Chyang

    2017-01-01

    Full Text Available The purpose of this paper is to develop a novel human-friendly artificial flexible robot arm using four parallel-connected pneumatic muscle actuators (PMAs. The PMA is a flexible silicone rubber actuator which has some behaviors nearest to the real biological muscle including translational and rotational motions. An inverse kinematic model for the motion control is also developed. Finally, from experiment results, it is proved that not only the axial contraction control of a single PMA but also the attitude control of the whole pneumatic flexible robot arm using PID controller are satisfactory.

  7. Control of pneumatic transfer system for neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. S.; Chung, Y. S.; Wu, J. S.; Kim, H. K.; Choi, Y. S.; Kim, S. H.; Moon, J. H.; Baek, S. Y

    2000-06-01

    Pneumatic transfer system(PTS) is one of the facilities to be used in irradiation of target materials for neutron activation analysis(NAA) in the research reactor. There are two systems the manual and the automatic system in PTS of HANARO research reactor. The pneumatic transfer system consists of many devices, sends and loads the capsules from NAA laboratory into three holes in the reflector tank of reactor and retrieves irradiated capsules after irradiation. This report describes the part's design, control system and the operation procedures. All the algorithm described in the text will be used for maintenance and upgrading.

  8. Empirical Analysis of Pneumatic Tire Friction on Ice

    OpenAIRE

    Holley, Troy Nigel

    2010-01-01

    Pneumatic tire friction on ice is an under-researched area of tire mechanics. This study covers the design and analysis of a series of pneumatic tire tests on a flat-level ice road surface. The terramechanics rig of the Advanced Vehicle Dynamics Lab (AVDL) is a single-wheel test rig that allows for the experimental analysis of the forces and moments on a tire, providing directly the data for the drawbar pull of said tire, thus supporting the calculation of friction based on this data. This...

  9. Electro-Pneumatic Control System with Hydraulically Positioning Actuator Motor

    OpenAIRE

    V. N. Pilgunov; K. D. Efremova

    2016-01-01

    A compressibility of the actuating fluid of a pneumatic drive (compressed air) leads to significant landing of the pneumatic cylinder piston at the time of stop and hold of the load, a constant component of which can fluctuate significantly for the holding period.There are a lot of factors, which have a significant impact on the landing value of piston. Those are: an initial position of the piston at its stop, which determines the volume of the an active area of the piston, a value of the con...

  10. Control of pneumatic transfer system for neutron activation analysis

    International Nuclear Information System (INIS)

    Jung, H. S.; Chung, Y. S.; Wu, J. S.; Kim, H. K.; Choi, Y. S.; Kim, S. H.; Moon, J. H.; Baek, S. Y.

    2000-06-01

    Pneumatic transfer system(PTS) is one of the facilities to be used in irradiation of target materials for neutron activation analysis(NAA) in the research reactor. There are two systems the manual and the automatic system in PTS of HANARO research reactor. The pneumatic transfer system consists of many devices, sends and loads the capsules from NAA laboratory into three holes in the reflector tank of reactor and retrieves irradiated capsules after irradiation. This report describes the part's design, control system and the operation procedures. All the algorithm described in the text will be used for maintenance and upgrading

  11. On the sample transport time of a pneumatic transfer system

    International Nuclear Information System (INIS)

    Kondo, Yoshihide

    1983-01-01

    The counts accumulated in measuring system are affected by the variations in transport time of the sample on cyclic activation experiments with a mechanical sample transfer system. In use of the pneumatic transfer system, which has been set up, the transport time is variable according to the differences as follows: The form, size and weight of samples, the pneumatic pressure and so on. Comprehending the relationships between the transpot time and these variable factors is essentially important to make experiments with this transfer system. (author)

  12. The facial nerve in the temporal bone as visualised via thin-layer paratransversal and sagittal MR tomographic images by means of T1 spin-echo and FLASH sequences

    International Nuclear Information System (INIS)

    Mueller-Lisse, U.; Jaeger, L.J.E.; Bruegel, F.J.; Grevers, G.; Reiser, M.F.

    1995-01-01

    It is difficult to effect visualization and delineation of the facial nerve and its neighbouring structures in the temporal bone with conventional MRI examination protocols. We tested temporal bone MRI with 2 mm slices and compared T 1 -weighted FLASH (T R =400 ms, T E =10 ms, 90 flip angle) and spin-echo (T R =540 ms, T E =15 ms) sequences. 5 volunteers and 14 patients were examined with the head coil of a 1.0 T whole body MRI scanner (Impact, Siemens, Erlangen) with para-transversal images orientated parallel to the inferior outline of the clivus and sagittal images orientated along the brainstem. The facial nerve and its neighbouring structures could be reliably visualized and differentiated along its entire course. The FLASH sequence was superior to the spin-echo sequence. 8 of 11 patients with peripheral facial nerve palsy showed contrast enhancement. In two patients, local swelling of the affected facial nerve was evident. (orig./MG) [de

  13. Design considerations for single-stage and two-stage pneumatic pellet injectors

    International Nuclear Information System (INIS)

    Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

    1988-09-01

    Performance of single-stage pneumatic pellet injectors is compared with several models for one-dimensional, compressible fluid flow. Agreement is quite good for models that reflect actual breech chamber geometry and incorporate nonideal effects such as gas friction. Several methods of improving the performance of single-stage pneumatic pellet injectors in the near term are outlined. The design and performance of two-stage pneumatic pellet injectors are discussed, and initial data from the two-stage pneumatic pellet injector test facility at Oak Ridge National Laboratory are presented. Finally, a concept for a repeating two-stage pneumatic pellet injector is described. 27 refs., 8 figs., 3 tabs

  14. Controlling pneumatic artificial muscles in exoskeletons with surface electromyography

    NARCIS (Netherlands)

    Groenhuis, Vincent; Chandrapal, Mervin; Stramigioli, Stefano; Chen, XiaoQi

    2014-01-01

    Powered exoskeletons are gaining more interest in the last few years, as useful devices to provide assistance to elderly and disabled people. Many different types of powered exoskeletons have been studied in the past. In this research paper, a soft lower limb exoskeleton driven by pneumatic

  15. Pneumatic conveying of sensitive compounds during nuclear fuel fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Sielck, Franz-Christian; Braehler, Georg [NUKEM Technologies GmbH (Germany)

    2009-07-01

    Any transport of nuclear material is associated with the risk of contamination after release into working areas or environment. stationary installed safe geometry vessels with pneumatic transfer between them offer unique safety features and reduce operating costs. The article describes the case of HTR fuel spheres, where a specially designed conveying system has been developed and the prototype conveyor has been tested.

  16. Pneumatic conveying of sensitive compounds during nuclear fuel fabrication

    International Nuclear Information System (INIS)

    Sielck, Franz-Christian; Braehler, Georg

    2009-01-01

    Any transport of nuclear material is associated with the risk of contamination after release into working areas or environment. stationary installed safe geometry vessels with pneumatic transfer between them offer unique safety features and reduce operating costs. The article describes the case of HTR fuel spheres, where a specially designed conveying system has been developed and the prototype conveyor has been tested.

  17. Systems of pneumatic transportation of cement and other fine ...

    African Journals Online (AJOL)

    Therefore, the operational reliability of such equipment decreases and the process of cleaning of the exhaust air becomes complicated. The solution of the problem of ... of the air expense and pressure during the design of the systems. Keywords: pneumatic transportation, fine materials. dust removal equipment, pape line.

  18. Rapid Prototyping High-Performance MR Safe Pneumatic Stepper Motors

    NARCIS (Netherlands)

    Groenhuis, Vincent; Stramigioli, Stefano

    2018-01-01

    In this paper we show that pneumatic stepper motors for MR safe robots can be constructed using rapid prototyping techniques such as 3-D printing and laser-cutting. The designs are lightweight, completely metal-free and fully customizable. Besides MR safe robotic systems, other potential

  19. Considerations of several real effects in pneumatic pellet injection processes

    International Nuclear Information System (INIS)

    Ming-Lun Xue.

    1987-10-01

    Several real effects that take place in a pneumatic pellet injector are examined. These are the heat transfer between a high-temperature propellent gas and the metal wall of the injector, and the frictional loss between the propellent and wall. (author)

  20. Pneumatic Dilation versus Laparoscopic Heller's Myotomy for Idiopathic Achalasia

    NARCIS (Netherlands)

    Boeckxstaens, Guy E.; Annese, Vito; des Varannes, Stanislas Bruley; Chaussade, Stanislas; Costantini, Mario; Cuttitta, Antonello; Elizalde, J. Ignasi; Fumagalli, Uberto; Gaudric, Marianne; Rohof, Wout O.; Smout, André J.; Tack, Jan; Zwinderman, Aeilko H.; Zaninotto, Giovanni; Busch, Olivier R.; Lei, A.; Bartelsman, J.; Hirsch, D.; Klinkenberg-Knol, E. C.; Cuesta, M. A.; Simmermacher, R. K. J.; Kuipers, E. J.; Bonjer, H. J.; Masclee, A. A. M.; Ringers, J.; Lerut, A.; Metman, E. H.; Huten, N.; Letessier, E.; Dousset, B.; Pera, M.; Perez de la Serna, J.; Malesci, Alberto; Andriulli, A.; Scaramuzzi, G.; de Santo, E.

    2011-01-01

    Background Many experts consider laparoscopic Heller's myotomy (LHM) to be superior to pneumatic dilation for the treatment of achalasia, and LHM is increasingly considered to be the treatment of choice for this disorder. Methods We randomly assigned patients with newly diagnosed achalasia to

  1. Intra-operative pneumatic tourniquet - perceptions of use and ...

    African Journals Online (AJOL)

    applied pressure alone or excessive applied pressure caused by use of faulty equipment. It needs to be emphasised to these surgeons that regular checking of the pneumatic tourniquet apparatus is necessary in order. MRC/UCT Bioenergetics of Exercise Research Unit, Department of. Physiology. University of Cape Town.

  2. Intra-operative pneumatic tourniquet - perceptions of use and ...

    African Journals Online (AJOL)

    Fifty-four per cent of respondents personally checked the calibration of the pneumatic tourniquet, although 76% of respondents believe that the apparatus needs to be checked at least once per month. More respondents who did not check the tourniquet apparatus than respondents who did check it believe that applied ...

  3. Pneumatic Actuation of a 2-Link Robotic System

    African Journals Online (AJOL)

    2012r

    2014-10-16

    Oct 16, 2014 ... are appropriate for “mixing, dumping, intermittent feeding, screw clamping ..... Let Aext be Area on which air is applied for extension. Let Aret ... Fext and Fret are the forces provided by the source of the pneumatic compressor.

  4. Transport Velocities of Different Particulate Materials in Pneumatic Conveying

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Pohořelý, Michael; Trnka, Otakar

    2006-01-01

    Roč. 60, č. 1 (2006), s. 74-77 ISSN 0366-6352 R&D Projects: GA AV ČR(CZ) IAA4072201 Institutional research plan: CEZ:AV0Z40720504 Keywords : fluidization * particle processing * pneumatic conveying Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.360, year: 2006

  5. Embedded Triboelectric Active Sensors for Real-Time Pneumatic Monitoring.

    Science.gov (United States)

    Fu, Xian Peng; Bu, Tian Zhao; Xi, Feng Ben; Cheng, Ting Hai; Zhang, Chi; Wang, Zhong Lin

    2017-09-20

    Pneumatic monitoring sensors have great demands for power supply in cylinder systems. Here, we present an embedded sliding triboelectric nanogenerator (TENG) in air cylinder as active sensors for position and velocity monitoring. The embedded TENG is composed of a circular poly(tetrafluoroethylene) polymer and a triangular copper electrode. The working mechanism as triboelectric active sensors and electric output performance are systematically investigated. By integrating into the pneumatic system, the embedded triboelectric active sensors have been used for real-time air pressure/flow monitoring and energy storage. Air pressures are measured from 0.04 to 0.12 MPa at a step of 0.02 MPa with a sensitivity of 49.235 V/MPa, as well as airflow from 50 to 250 L/min at a step of 50 L/min with a sensitivity of 0.002 μA·min/L. This work has first demonstrated triboelectric active sensors for pneumatic monitoring and may promote the development of TENG in intelligent pneumatic system.

  6. High Efficiency Pneumatic Systems Compressors Hydrodynamics and Termodynamics Process Research

    Directory of Open Access Journals (Sweden)

    Paulius Bogdevičius

    2016-12-01

    Full Text Available The paper analyzes pneumatic system, which consists of three piston compressors, pipes and reciever. Designed two cylinder piston compressor with an asynchronous electric motor mathematical model. In the mathematical model has been estimated rod mechanism geometry and kinematic parameters also hudrodynamics and thermodynamic processes going in the cylinders. Also there were made mathematical experiment and presented the results of it.

  7. Pneumatic motor speed control by trajectory tracking fuzzy logic

    Indian Academy of Sciences (India)

    In this study, trajectory tracking fuzzy logic controller (TTFLC) is proposed for the speed control of a pneumatic motor (PM). A third order trajectory is defined to determine the trajectory function that has to be tracked by the PM speed. Genetic algorithm (GA) is used to find the TTFLC boundary values of membership functions ...

  8. Integration of Pneumatic Technology in Powered Mobility Devices.

    Science.gov (United States)

    Daveler, Brandon; Wang, Hongwu; Gebrosky, Benjamin; Grindle, Garrett G; Schneider, Urs; Cooper, Rory A

    2017-01-01

    Advances in electric motors, electronics, and control systems have enhanced the capability and drivability of electric power mobility devices over the last 60 years. Yet, battery technologies used in powered mobility devices (PMDs) have not kept pace. Recent advances in pneumatic technology, primarily the high torque, low speed design of rotary piston air motors, directly align with the needs of PMD. Pneumatic technology has advantages over battery-powered technology, including lighter weight, lower operating costs, decreased environmental impact, better reliability, and increased safety. Two prototypes were created that incorporated rotary piston air motors, high-pressure air tanks, and air-pressure regulators. Prototype 1 was created by modifying an existing electric PMD. Range tests were performed to determine the feasibility of pneumatic technology and the optimal combination of components to allow the longest range possible at acceptable speeds over ideal conditions. Using a 1.44 L air tank for feasibility testing, prototype 1 was capable of traveling 800 m, which confirmed the feasibility of pneumatic technology usage in PMDs. Prototype 2 was designed based on the testing results from prototype 1. After further optimization of prototype 2, the average maximum range was 3,150 m. Prototype 2 is up to 28.3% lighter than an equivalent size electric PMD and can be fully recharged in approximately 2 minutes. It decreases the cost of PMDs by approximately $1,500, because batteries do not need to be replaced over the lifetime of the device. The results provide justification for the use of pneumatic technology in PMDs.

  9. Pneumatic fractures in Confined Granular Media

    Science.gov (United States)

    Eriksen, Fredrik K.; Toussaint, Renaud; Jørgen Måløy, Knut; Grude Flekkøy, Eirik; Turkaya, Semih

    2016-04-01

    We will present our ongoing study of the patterns formed when air flows into a dry, non-cohesive porous medium confined in a horizontal Hele-Shaw cell. This is an optically transparent system consisting of two glass plates separated by 0.5 to 1 mm, containing a packing of dry 80 micron beads in between. The cell is rectangular and has an air-permeable boundary (blocking beads) at one short edge, while the other three edges are completely sealed. The granular medium is loosely packed against the semi-permeable boundary and fills about 80 % of the cell volume. This leaves an empty region at the sealed side, where an inlet allows us to set and maintain the air at a constant overpressure (0.1 - 2 bar). For the air trapped inside the cell to relax its overpressure it has to move through the deformable granular medium. Depending on the applied overpressure and initial density of the medium, we observe a range of different behaviors such as seepage through the pore-network with or without an initial compaction of the solid, formation of low density bubbles with rearrangement of particles, granular fingering/fracturing, and erosion inside formed channels/fractures. The experiments are recorded with a high-speed camera at a framerate of 1000 images/s and a resolution of 1024x1024 pixels. We use various image processing techniques to characterize the evolution of the air invasion patterns and the deformations in the surrounding material. The experiments are similar to deformation processes in porous media which are driven by pore fluid overpressure, such as mud volcanoes and hydraulic or pneumatic (gas-induced) fracturing, and the motivation is to increase the understanding of such processes by optical observations. In addition, this setup is an experimental version of the numerical models analyzed by Niebling et al. [1,2], and is useful for comparison with their results. In a directly related project [3], acoustic emissions from the cell plate are recorded during

  10. Bone tumors

    International Nuclear Information System (INIS)

    Unni, K.K.

    1988-01-01

    This book contains the proceedings on bone tumors. Topics covered include: Bone tumor imaging: Contribution of CT and MRI, staging of bone tumors, perind cell tumors of bone, and metastatic bone disease

  11. An Application of a Pneumatic Muscles Actuator for a Delta Pneumatic Manipulator

    Directory of Open Access Journals (Sweden)

    Pawel A. LASKI

    2014-12-01

    Full Text Available The main aim of this study was to use pneumatic muscle actuators in the construction of the delta manipulator with a closed kinematic chain. The paper presents a solid models of the manipulator and the kinematic diagram. Based on the kinematic diagram and using DH notation (Denavit-Hartenberg manipulator kinematic models was determined. On the basis of developed solid model simulation studies were conducted and the shape and size of the workspace determined. On the basis of 3D models prototype of the manipulator was constructed. Experimental studies were performed to select the regulators settings P, PI, PID for one of the pair of BMDS (Bi-Muscular Driving System muscle-type drives. Based on integral quality indicators the used types of regulators were compared and proposed final controller. Performed experimental studies confirm the possibility of muscle control in the BMDS (Bi-Muscular Driving System type system drives and tuning controller settings using the Ziegler-Nichols method.

  12. Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

    Science.gov (United States)

    Fan, Ji-Zhuang; Zhang, Wei; Kong, Peng-Cheng; Cai, He-Gao; Liu, Gang-Feng

    2017-09-01

    Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

  13. Simulation of biomass pneumatic drying with ascending swirling movement

    International Nuclear Information System (INIS)

    Bombino Matos, Eugenio F.; Pineda Revilla, Edel

    2017-01-01

    Considering the layer form acquired by the particles during the studying process it was necessary to define the relation cheap between the heat and mass transfer area and particles flow to simulate with more precision this kind of drying. The simulations results were compared, by a statistical analysis based in Statgraphics-Centurion V15 program, with the results obtained in others pneumatic bagasse dryers studies and were similar and for that reason it was categorical that is correct the definition made about the relation cheap area/material flow defined in this work and it’s possible to reduce pneumatic dryer height by using this method. This reduction that can be seen by the Height Reduction Sing (HRS) of the drying column, defined in the work, will permit more compact dryers. (author)

  14. Performance characterization of pneumatic single pellet injection system

    International Nuclear Information System (INIS)

    Schuresko, D.D.; Milora, S.L.; Hogan, J.T.; Foster, C.A.; Combs, S.K.

    1983-01-01

    The Oak Ridge National Laboratory single-shot pellet injector, which has been used in plasma fueling experiments on ISX and PDX, has been upgraded and extensively instrumented in order to study the gas dyamics of pneumatic pellet injection. An improved pellet transport line was developed which utilizes a 0.3-cm-diam by 100-cm-long guide tube. Pellet gun performance was characterized by measurements of breech and muzzle dynamic pressures and by pellet velocity and mass determinations. Velocities of up to 1.4 km/s were achieved for intact hydrogen pellets using hydrogen propellant at 5-MPa breech pressure. These data have been compared with new pellet acceleration calculations which include the effects of propellant friction, heat transfer, time-dependent boundary conditions, and finite gun geometry. These results provide a basis for the extrapolation of present-day pneumatic injection system performance to velocities in excess of 2 km/s

  15. The Influence of Shaping Air Pressure of Pneumatic Spray Gun

    Science.gov (United States)

    Chen, Wenzhuo; Chen, Yan; Pan, Haiwei; Zhang, Weiming; Li, Bo

    2018-02-01

    The shaping air pressure is a very important parameter in the application of pneumatic spray gun, and studying its influence on spray flow field and film thickness distribution has practical values. In this paper, Euler-Lagrangian method is adopted to describe the two-phase spray flow of pneumatic painting process, and the air flow fields, spray patterns and dynamic film thickness distributions were obtained with the help of the computational fluid dynamics code—ANSYS Fluent. Results show that with the increase of the shaping air pressure, the air phase flow field spreads in the plane perpendicular to the shaping air hole plane, the spray pattern becomes narrower and flatter, and the width of the dynamic film increases with the reduced maximum value of the film thickness. But the film thickness distribution seems to change little with the shaping air pressure decreasing from 0.6bar to 0.9bar.

  16. Liquid-metal dip seal with pneumatic spring

    International Nuclear Information System (INIS)

    Poindexter, A.M.

    1977-01-01

    An improved liquid-metal dip seal for sealing the annulus between rotating plugs in the reactor vessel head of a liquid-metal fast-breeder nuclear reactor has two legs of differing widths communicating under a seal blade; the wide leg is also in communication with cover gas of the reactor and the narrow leg is also in communication with an isolated plug annulus above the seal. The annulus contains inert gas which acts as a pneumatic spring. Upon increasing cover gas pressure which depresses the level in the wide leg and greatly increases the level in the narrow leg, the pneumatic spring is compressed, and resists further level changes, thus preventing radioactive cover gas from bubbling through the seal

  17. Elbow joint rehabilitation equipment actuated by pneumatic muscles

    Directory of Open Access Journals (Sweden)

    Vetrice Georgiana

    2017-01-01

    Full Text Available The mobility of the limbs is an essential prerequisite for the individual’s physical autonomy. For persons suffering from post-traumatic affections of the elbow joint such limited mobility results in barriers in fulfilling personal or professional tasks. Passive motion has certain specific advantages and beneficial effects, thus being highly recommended for the recovery of injured joints. The paper presents a model of rehabilitation equipment that induces continuous passive motion of the elbow, as part of a recovery programme. The equipment is actuated by pneumatic muscles, using compressed air as the source of energy that generates force and motion. The main benefits of the pneumatic actuation system compared to other driving systems are its low cost, simple and robust construction and swift response to commands. Its constructive simplicity and reduced cost adds to the system’s eligibility for deployment in medical units.

  18. Performance characterization of pneumatic single pellet injection system

    International Nuclear Information System (INIS)

    Schuresko, D.D.; Milora, S.L.; Hogan, J.T.; Foster, C.A.; Combs, S.K.

    1982-01-01

    The Oak Ridge National Laboratory single-shot pellet injector, which has been used in plasma fueling experiments on ISX and PDX, has been upgraded and extensively instrumented in order to study the gas dynamics of pneumatic pellet injection. An improved pellet transport line was developed which utilizes a 0.3-cm-diam by 100-cm-long guide tube. Pellet gun performance was characterized by measurements of breech and muzzle dynamic pressures and by pellet velocity and mass determinations. Velocities up to 1.4 km/s were achieved for intact hydrogen pellets using hydrogen propellant at 5-MPa breech pressure. These data have been compared with new pellet acceleration calculations which include the effects of propellant friction, heat transfer, time-dependent boundary conditions, and finite gun geometry. These results provide a basis for the extrapolation of present-day pneumatic injection system performance to velocities in excess of 2 km/s

  19. Research of pneumatic control transmission system for small irradiation samples

    International Nuclear Information System (INIS)

    Bai Zhongxiong; Zhang Haibing; Rong Ru; Zhang Tao

    2008-01-01

    In order to reduce the absorbed dose damage for the operator, pneumatic control has been adopted to realize the rapid transmission of small irradiation samples. On/off of pneumatic circuit and directions for the rapid transmission system are controlled by the electrical control part. The main program initializes the system and detects the location of the manual/automatic change-over switch, and call for the corresponding subprogram to achieve the automatic or manual operation. Automatic subprogram achieves the automatic sample transmission; Manual subprogram completes the deflation, and back and forth movement of the radiation samples. This paper introduces in detail the implementation of the system, in terms of both hardware and software design. (authors)

  20. Dielectric elastomer actuators used for pneumatic valve technology

    International Nuclear Information System (INIS)

    Giousouf, Metin; Kovacs, Gabor

    2013-01-01

    Dielectric elastomer actuators have been investigated for applications in the field of pneumatic automation technology. We have developed different valve designs with stacked dielectric elastomer actuators and with integrated high voltage converters. The actuators were made using VHB-4910 material and a stacker machine for automated fabrication of the cylindrical actuators. Typical characteristics of pneumatic valves such as flow rate, power consumption and dynamic behaviour are presented. For valve construction the force and stroke parameters of the dielectric elastomer actuator have been measured. Further, benefits for valve applications using dielectric elastomers are shown as well as their potential operational area. Finally, challenges are discussed that are relevant for the use of elastomer actuators in valves for industrial applications. (paper)

  1. Microcomputer-based pneumatic controller for neutron activation analysis

    International Nuclear Information System (INIS)

    Byrd, J.S.; Sand, R.J.

    1976-10-01

    A microcomputer-based pneumatic controller for neutron activation analysis was designed and built at the Savannah River Laboratory for analysis of large numbers of geologic samples for locating potential supplies of uranium ore for the National Uranium Resource Evaluation program. In this system, commercially available microcomputer logic modules are used to transport sample capsules through a network of pressurized air lines. The logic modules are interfaced to pneumatic valves, solenoids, and photo-optical detectors. The system operates from programs stored in firmware (permanent software). It also commands a minicomputer and a hard-wired pulse height analyzer for data collection and bookkeeping tasks. The advantage of the system is that major system changes can be implemented in the firmware with no hardware changes. This report describes the hardware, firmware, and software for the electronics system

  2. Pneumatic dilatation in achalasia cardia results and follow-up.

    Directory of Open Access Journals (Sweden)

    Supe A

    1990-10-01

    Full Text Available Pneumatic dilatation is one of the more recent methods in the management of achalasia cardia. Fifty dilatations were done in 42 patients with achalasia cardia over 5 years. There was a significant decrease in the maximum diameter of the oesophagus and a significant increase in diameter in the narrowed lower oesophageal segment in all the patients. Of the patients studied, 95.23% were relieved of their symptoms after only one to two sessions. There were no immediate complications. Out of the 38 patients on long term follow up, 8 (21.05% had recurrence of symptoms. On repeat dilatations, 4 (50% of them had good response. Late complication like reflux oesophagitis was observed in only 1 patient over a median follow up period of 22 months. It was thus concluded that pneumatic dilatation is a safe, simple and effective procedure in managing patients with achalasia cardia.

  3. Neuropatía sensitiva trigeminal secundaria a granuloma de colesterol de la punta del peñasco del temporal Trigeminal neuralgia secondary to cholesterol granuloma of the petrous bone apex

    Directory of Open Access Journals (Sweden)

    M.A. Pons García

    2009-10-01

    Full Text Available La neuropatía aislada de la rama sensitiva del trigémino es una entidad poco habitual. Los pacientes suelen referir hipoestesia y /o disestesia generalmente a nivel de la segunda y tercera rama del trigémino, mientras que la neuralgia es muy infrecuente.¹ Su asociación con enfermedades sistémicas del tejido conectivo es bien conocida.² Se ha descrito asociada a distintas lesiones del SNC sobre todo tumores de fosa posterior o base de cráneo, así como neoplasias mandibulares.3,4 Presentamos una paciente con hipoestesia en el territorio V2-V3 asociada a dolor hemifacial paroxístico secundario a una lesión del peñasco del temporal.Trigeminal Neuralgia is an uncommon entity. The patients report hypoesthesia and/or dysesthesia of the second and third ramus of trigeminal nerve, while neuralgia is very rare.¹ Its association with systemic diseases of connective tissue is well know.² It has been described as being associated with different lesions of the central nervous system, especially with the posterior cavity or cranial base tumors, as well as jaw neoplasias.3,4 We presented a patient with hypoesthesia V2-V3 and hemi facial paroxysmal pain secondary to lesion of petrous apex of temporal bone.

  4. Pneumatic Muscle Actuated Equipment for Continuous Passive Motion

    Science.gov (United States)

    Deaconescu, Tudor T.; Deaconescu, Andrea I.

    2009-10-01

    Applying continuous passive rehabilitation movements as part of the recovery programme of patients with post-traumatic disabilities of the bearing joints of the inferior limbs requires the development of new high performance equipment. This chapter discusses a study of the kinematics and performance of such a new, continuous passive motion based rehabilitation system actuated by pneumatic muscles. The utilized energy source is compressed air ensuring complete absorption of the end of stroke shocks, thus minimizing user discomfort.

  5. Pneumatic Muscle Actuated Rehabilitation Equipment of the Upper Limb Joints

    Science.gov (United States)

    Deaconescu dr. eng. habil., Andrea, Prof.

    2017-06-01

    Rehabilitation equipment of the upper limb joints holds a key role in passive physical therapy. Within this framework, the paper presents two such pieces of equipment developed for the rehabilitation of elbow and of wrist and knuckles, respectively. The presented and discussed equipment is actuated by pneumatic muscles, its benefits being a low cost, simple and robust construction, as well as short response time to commands.

  6. Measurement of Static Characteristics Pneumatic Motors with Elastic Working Elements

    Directory of Open Access Journals (Sweden)

    Kamil FOJTÁŠEK

    2012-06-01

    Full Text Available Into a category of pneumatic motors with elastic working parts belong air bellows, diaphragm motors and fluid muscles. All three types of these motors have some elastic part usually made of rubber. This part is deformed under the pressure of a compressed air or a mass load resulting in a final working effect. This paper deals with measuring of static characteristics of these motors.

  7. Dynamic Analysis of Sounding Rocket Pneumatic System Revision

    Science.gov (United States)

    Armen, Jerald

    2010-01-01

    The recent fusion of decades of advancements in mathematical models, numerical algorithms and curve fitting techniques marked the beginning of a new era in the science of simulation. It is becoming indispensable to the study of rockets and aerospace analysis. In pneumatic system, which is the main focus of this paper, particular emphasis will be placed on the efforts of compressible flow in Attitude Control System of sounding rocket.

  8. Quantification of dynamic property of pneumatic muscle actuator for design of therapeutic robot control.

    Science.gov (United States)

    Balasubramanian, Sivakumar; Huang, He; He, Jiping

    2006-01-01

    Robot-assisted therapy has shown potential in neuromotor rehabilitation. A therapeutic robot driven by pneumatic muscle actuators has been developed in our research group. However, the design of fine and real-time feedback robot control is a challenge. One of the difficulties is the lack of a general dynamic model of the pneumatic muscle actuator. In this study, a phenomenological model has been developed to quantify the dynamic behavior of pneumatic muscle actuator by fitting the experimental length response of the pneumatic muscle, to a step pressure input. In addition, comparison of the dynamic responses of two pneumatic muscles of different dimensions has also been studied. Several control strategies for the pneumatic muscle actuator are discussed based on the results from this study.

  9. A study on the design of a low-friction, high-speed pneumatic cylinder

    International Nuclear Information System (INIS)

    Kim, Do Tae; Kim, Dong Soo; Ju, Min Jin

    2008-01-01

    Of all of pneumatic components utilized in the make up of pneumatic circuits on either automatic assembly machine or industrial equipment, the pneumatic cylinder is more oriented toward being a structural as well as a pneumatic member. The structural design must be based to a large degree on the end of application of the cylinder on the equipment it is operating. In this paper, design studies of a double-acting pneumatic cushion type cylinder with low-friction and high-speed driving have been developed. Of interest here is to investigate the structural analysis of cylinder tube, piston rod, end cover, and to analyze the buckling of piston rod. Also, a relief valve type cushion mechanism is considered. This cushion mechanism is found to be adequate under a high-speed driving of pneumatic cylinders

  10. Electric-Pneumatic Actuator: A New Muscle for Locomotion

    Directory of Open Access Journals (Sweden)

    Maziar Ahmad Sharbafi

    2017-10-01

    Full Text Available A better understanding of how actuator design supports locomotor function may help develop novel and more functional powered assistive devices or robotic legged systems. Legged robots comprise passive parts (e.g., segments, joints and connections which are moved in a coordinated manner by actuators. In this study, we propose a novel concept of a hybrid electric-pneumatic actuator (EPA as an enhanced variable impedance actuator (VIA. EPA is consisted of a pneumatic artificial muscle (PAM and an electric motor (EM. In contrast to other VIAs, the pneumatic artificial muscle (PAM within the EPA provides not only adaptable compliance, but also an additional powerful actuator with muscle-like properties, which can be arranged in different combinations (e.g., in series or parallel to the EM. The novel hybrid actuator shares the advantages of both integrated actuator types combining precise control of EM with compliant energy storage of PAM, which are required for efficient and adjustable locomotion. Experimental and simulation results based on the new dynamic model of PAM support the hypothesis that combination of the two actuators can improve efficiency (energy and peak power and performance, while does not increase control complexity and weight, considerably. Finally, the experiments on EPA adapted bipedal robot (knee joint of the BioBiped3 robot show improved efficiency of the actuator at different frequencies.

  11. Design and control of a pneumatic musculoskeletal biped robot.

    Science.gov (United States)

    Zang, Xizhe; Liu, Yixiang; Liu, Xinyu; Zhao, Jie

    2016-04-29

    Pneumatic artificial muscles are quite promising actuators for humanoid robots owing to their similar characteristics with human muscles. Moreover, biologically inspired musculoskeletal systems are particularly important for humanoid robots to perform versatile dynamic tasks. This study aims to develop a pneumatic musculoskeletal biped robot, and its controller, to realize human-like walking. According to the simplified musculoskeletal structure of human lower limbs, each leg of the biped robot is driven by nine muscles, including three pairs of monoarticular muscles which are arranged in the flexor-extensor form, as well as three biarticular muscles which span two joints. To lower cost, high-speed on/off solenoid valves rather than proportional valves are used to control the muscles. The joint trajectory tracking controller based on PID control method is designed to achieve the desired motion. Considering the complex characteristics of pneumatic artificial muscles, the control model is obtained through parameter identification experiments. Preliminary experimental results demonstrate that the biped robot is able to walk with this control strategy. The proposed musculoskeletal structure and control strategy are effective for the biped robot to achieve human-like walking.

  12. Soft Pneumatic Bending Actuator with Integrated Carbon Nanotube Displacement Sensor

    Directory of Open Access Journals (Sweden)

    Tim Giffney

    2016-02-01

    Full Text Available The excellent compliance and large range of motion of soft actuators controlled by fluid pressure has lead to strong interest in applying devices of this type for biomimetic and human-robot interaction applications. However, in contrast to soft actuators fabricated from stretchable silicone materials, conventional technologies for position sensing are typically rigid or bulky and are not ideal for integration into soft robotic devices. Therefore, in order to facilitate the use of soft pneumatic actuators in applications where position sensing or closed loop control is required, a soft pneumatic bending actuator with an integrated carbon nanotube position sensor has been developed. The integrated carbon nanotube position sensor presented in this work is flexible and well suited to measuring the large displacements frequently encountered in soft robotics. The sensor is produced by a simple soft lithography process during the fabrication of the soft pneumatic actuator, with a greater than 30% resistance change between the relaxed state and the maximum displacement position. It is anticipated that integrated resistive position sensors using a similar design will be useful in a wide range of soft robotic systems.

  13. Design and Control of a Pneumatically Actuated Transtibial Prosthesis.

    Science.gov (United States)

    Zheng, Hao; Shen, Xiangrong

    2015-04-01

    This paper presents the design and control of a pneumatically actuated transtibial prosthesis, which utilizes a pneumatic cylinder-type actuator to power the prosthetic ankle joint to support the user's locomotion. The pneumatic actuator has multiple advantages over the traditional electric motor, such as light weight, low cost, and high power-to-weight ratio. The objective of this work is to develop a compact and lightweight transtibial prosthesis, leveraging the multiple advantages provided by this highly competitive actuator. In this paper, the design details of the prosthesis are described, including the determination of performance specifications, the layout of the actuation mechanism, and the calculation of the torque capacity. Through the authors' design calculation, the prosthesis is able to provide sufficient range of motion and torque capacity to support the locomotion of a 75 kg individual. The controller design is also described, including the underlying biomechanical analysis and the formulation of the finite-state impedance controller. Finally, the human subject testing results are presented, with the data indicating that the prosthesis is able to generate a natural walking gait and sufficient power output for its amputee user.

  14. Homogeneity of blended nuclear fuel powders after pneumatic transport

    International Nuclear Information System (INIS)

    Smeltzer, E.E.; Skriba, M.C.; Lyon, W.L.

    1982-01-01

    A study of the pneumatic transport of fine (approx. 1μm) cohesive nuclear fuel powders was conducted for the U.S. Department of Energy to demonstrate the feasibility of this method of transport and to develop a design data base for use in a large scale nuclear fuel production facility. As part of this program, a considerable effort was directed at following the homogeneity of blended powders. Since different reactors require different enrichments, blending and subsequent transport are critical parts of the fabrication sequence. The various materials used represented analogs of a wide range of powders and blends that could be expected in a commercial mixed oxide fabrication facility. All UO 2 powders used were depleted and a co-precipitated master mix of (U, Th)O 2 was made specifically for this program, using thorium as an analog for plutonium. In order to determine the effect of pneumatic transport on a blended powder, samples were taken from a feeder vessel before each test, and from a receiver vessel and a few line sections after each transfer test. The average difference between the before and after degree of non-homogeneity was < 1%, for the 21 tests considered. This shows that overall, the pneumatic transport of blended, fine nuclear fuel powders is possible, with only minor unblending occurring

  15. Force Control for a Pneumatic Cylinder Using Generalized Predictive Controller Approach

    OpenAIRE

    Mohd Faudzi, Ahmad ’Athif; Mustafa, Nu’man Din; Osman, Khairuddin

    2014-01-01

    Pneumatic cylinder is a well-known device because of its high power to weight ratio, easy use, and environmental safety. Pneumatic cylinder uses air as its power source and converts it to a possible movement such as linear and rotary movement. In order to control the pneumatic cylinder, controller algorithm is needed to control the on-off solenoid valve with encoder and pressure sensor as the feedback inputs. In this paper, generalized predictive controller (GPC) is proposed as the control st...

  16. Vibration and recoil control of pneumatic hammers. [by air flow pressure regulation

    Science.gov (United States)

    Constantinescu, I. N.; Darabont, A. V.

    1974-01-01

    Vibration sources are described for pneumatic hammers used in the mining industry (pick hammers), in boiler shops (riveting hammers), etc., bringing to light the fact that the principal vibration source is the variation in air pressure inside the cylinder. The present state of the art of vibration control of pneumatic hammers as it is practiced abroad, and the solutions adopted for this purpose, are discussed. A new type of pneumatic hammer with a low noise and vibration level is presented.

  17. Pneumatic artificial muscle and its application on driving variable trailing-edge camber wing

    Science.gov (United States)

    Yin, Weilong; Liu, Libo; Chen, Yijin; Liu, Yanju; Leng, Jinsong

    2010-04-01

    As a novel bionic actuator, pneumatic artificial muscle has high power to weight ratio. In this paper, the experimental setup to measure the static output force of pneumatic artificial muscle was designed and the relationship between the static output force and the air pressure was investigated. Experimental result shows the static output force of pneumatic artificial muscle decreases nonlinearly with increasing contraction ratio. A variable camber wing based on the pneumatic artificial muscle was developed and the variable camber wing model was manufactured to validate the variable camber concept. Wind tunnel tests were conducted in the low speed wind tunnel. Experimental result shows that the wing camber increases with increasing air pressure.

  18. Development of a pneumatic transfer system for HTGR recycle fuel particles

    International Nuclear Information System (INIS)

    Mack, J.E.; Johnson, D.R.

    1978-02-01

    In support of the High-Temperature Gas-Cooled Reactor (HTGR) Fuel Refabrication Development Program, an experimental pneumatic transfer system was constructed to determine the feasibility of pneumatically conveying pyrocarbon-coated fuel particles of Triso and Biso designs. Tests were conducted with these particles in each of their nonpyrophoric forms to determine pressure drops, particle velocities, and gas flow requirements during pneumatic transfer as well as to evaluate particle wear and breakage. Results indicated that the material can be pneumatically conveyed at low pressures without excessive damage to the particles or their coatings

  19. Radionuclide esophageal emptying study before and after pneumatic dilatation in achalasia

    Energy Technology Data Exchange (ETDEWEB)

    Ujiie, Hiroaki; Hongo, Michio; Lin, Yih-Fong; Satake, Kenzo; Asaki, Shigeru; Goto, Yoshio; Okuyama, Shinichi

    1987-11-01

    The therapeutic effect of pneumatic dilatation was evaluated quantitatively by radionuclide transit study in 11 achalasia patients. Before pneumatic dilatation, marked retention with more than 80 % of isotope in the esophagus at 15 minutes after ingestion was noted in all patients. Marked improvement in emptying was shown after pneumatic dilatation. Pneumatic dilatation is a safe and effective therapeutic aid for achalasia treatment, and radionuclide transit study is not only noninvasive and physiologic but also its procedure is easily performed. We conclude that radionuclide transit study is a good method to evaluate the result of the treatment quantitatively in achalasia patients.

  20. Application of Model Based Prognostics to Pneumatic Valves in a Cryogenic Propellant Loading Testbed

    Data.gov (United States)

    National Aeronautics and Space Administration — Pneumatic-actuated valves are critical components in many applications, including cryogenic propellant loading for space operations. For these components, failures...

  1. Utilization of pneumatic energy in industries and Nuclear Energy Unit - a brief review

    International Nuclear Information System (INIS)

    Muhd Noor Muhd Yunus

    1984-01-01

    The purpose of this paper is to evaluate the extent of utilisation of pneumatic energy in UTN, besides depicting the capabilities of pneumatics in various field, especially in nuclear industry. Thus, a few examples of the usage of this energy in industry and UTN are explained and listed briefly. Comparisons and advantages of the pneumatics with respect to other forms of energy also discussed briefly. It is hoped that this pneumatic technology will advanced in UTN and becoming one of the alternatives of offered apart from other form of energy like hyrdaulics and electricity. (author)

  2. DETERMINATION OF CHARACTERISTICS OF THROTTLING DEVICE FOR PNEUMATIC SPRING

    Directory of Open Access Journals (Sweden)

    O. H. Reidemeister

    2018-02-01

    Full Text Available Purpose. This paper focuses on determination of the dependence of the working medium flow on the capacity of the throttling device, its geometric features and the pressure difference in the pneumatic spring cylinder and in the auxiliary reservoir. Methodology. Calculation of the dependence of the working medium and pressure drop is performed in two ways: 1 by numerical simulation of a stationary gas flow through a throttling element; 2 its analytical calculation expression using empirical relationships (control calculation to evaluate the reliability of numerical simulation results. For the calculation, three models of throttling devices were chosen. Dependence of the flow rate of the working medium on the capacity of the throttling device and its geometric features was determined based on the approximation of the dependency graphs of the pressure drop against the mass flow rate of the working medium. Findings. We obtained graphical dependencies between the pressure drop and the mass flow rate of the working medium from the two calculation options. Based on the results of calculations performed with the help of a software package with visualization of the results, we calculated a proportionality coefficient that describes the dependence of the working medium flow on the throttling device capacity and its geometric features for each of the throttling elements considered, with three degrees of closure. The air flow values, obtained by numerical simulation, are greater than the flow rates obtained from semi-empirical formulas. At the same time, they are in good qualitative agreement, and the quantitative difference averages 25%, which can be regarded as confirmation of the reliability of the nu-merical model. Based on the calculation results, we plotted the proportionality coefficient graphs against the degree of closure of the throttling device. Originality. The work allows determining the degree of influence of the frictio-nal component on the

  3. [Accident-induced lesions of the facial nerve in relation to the extent of pyramidal pneumatization].

    Science.gov (United States)

    Kadoori, S; Limberg, C

    1985-12-01

    Perilabyrinthine pneumatisation of the petrous pyramid constitutes a risk factor for the facial nerve in its labyrinthine part in a fracture of the temporal bone because serious splintering of bone is possible. Splinters dislocated into the Fallopian canal may damage the nerve seriously. On the other hand a perineural haematoma can flow out of the canal into the neighbouring cells through dehiscences or through the fractured canal walls and a compression of the nerve may be avoided. The decision to undertake early surgical intervention must take into account the degree of pneumatisation of the pyramid in posttraumatic lesions of the facial nerve. The timing and extent of recovery cannot be predicted.

  4. Searching for new features of intravitality of hanging based on macro- and microscopic evaluation of the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone.

    Science.gov (United States)

    Szleszkowski, Ł; Hałoń, A; Thannhäuser, A; Jurek, T

    2015-01-01

    Assessment of the usefulness of intravital lesions in the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone in medico-legal evaluation of death by hanging. The study material was obtained from the bodies of 35 people who died by hanging. The control group comprised specimens collected from 30 people who died of non-traumatic causes. The structures under study were examined macro- and microscopically. The basic change which could be recognized as a marker of intravitality of hanging was the presence of a macroscopically extensive blotchy area of abundant ecchymosis in the proximal muscle attachment, similar to that found in the distal attachment, and the presence of abundant diffuse intraosseous ecchymoses in the mastoid process. None of the cases revealed any ecchymoses in the proximal attachment of the muscle that would be similar to those present in the distal attachment. Discolourations within the mastoid processes, macroscopically suggestive of extensive intraosseous effusions arising from the mechanism of stretching, were not confirmed by microscopic evaluation and occurred at the same frequency as in the control group. Limitations of the study were related to the method which involved sample collection by means of bone chisels, decalcification and preparation of specimens, which had an effect, for example, on the measurable evaluation of the degree of congestion. The study has failed to provide convincing and unambiguous data on the usefulness of examining mastoid processes and proximal attachments of the sternocleidomastoid muscles during autopsy to determine the presence of intravitality features of hanging. A description of research methodology and its associated difficulties, e.g. with the interpretation of results, can also be useful for the planning of similar studies by other researchers.

  5. Searching for new features of intravitality of hanging based on macro- and microscopic evaluation of the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone

    Directory of Open Access Journals (Sweden)

    Łukasz Szleszkowski

    2016-03-01

    Full Text Available Aim of the study : Assessment of the usefulness of intravital lesions in the proximal attachment of the sternocleidomastoid muscle and the mastoid process of the temporal bone in medico-legal evaluation of death by hanging. Material and methods: The study material was obtained from the bodies of 35 people who died by hanging. The control group comprised specimens collected from 30 people who died of non-traumatic causes. The structures under study were examined macro- and microscopically. The basic change which could be recognized as a marker of intravitality of hanging was the presence of a macroscopically extensive blotchy area of abundant ecchymosis in the proximal muscle attachment, similar to that found in the distal attachment, and the presence of abundant diffuse intraosseous ecchymoses in the mastoid process. Results: None of the cases revealed any ecchymoses in the proximal attachment of the muscle that would be similar to those present in the distal attachment. Discolourations within the mastoid processes, macroscopically suggestive of extensive intraosseous effusions arising from the mechanism of stretching, were not confirmed by microscopic evaluation and occurred at the same frequency as in the control group. Limitations of the study were related to the method which involved sample collection by means of bone chisels, decalcification and preparation of specimens, which had an effect, for example, on the measurable evaluation of the degree of congestion. Conclusions : The study has failed to provide convincing and unambiguous data on the usefulness of examining mastoid processes and proximal attachments of the sternocleidomastoid muscles during autopsy to determine the presence of intravitality features of hanging. A description of research methodology and its associated difficulties, e.g. with the interpretation of results, can also be useful for the planning of similar studies by other researchers.

  6. Muscle- and pneumatic-powered counterpulsating LVADs: a pilot study.

    Science.gov (United States)

    Wilde, J C; van Loon, J; Bishop, N D; Shelton, A D; Marten, C; Kolff, W J; Stephenson, L; Baciewicz, F; Nakajima, H; Thomas, G

    1994-03-01

    There is a worldwide interest in supporting the failing heart with a skeletal muscle by either wrapping it around the natural heart (dynamic cardiomyoplasty) or by constructing a skeletal muscle ventricle (SMV) used for counterpulsation. Conventional cardiomyoplasty in many clinics carries an operative mortality rate of 15-20% partly because it requires 6 weeks to train the muscle to contract continually. A flexible, pear-shaped blood pump with an inflatable air chamber was designed and made around which a muscle can be wrapped. The advantage of our design is that it can also be driven by pneumatic power, immediately supporting the circulation of a seriously ill patient while that patient is still on the operating table. After a period of time to allow for revascularization and the subsequent training of the muscle, the external pneumatic power can be gradually discontinued. Then the assisted patient becomes tether-free. If, at any time, the muscle power fails, the pneumatic-powered mechanism can be reactivated. In the preferred approach, the blood pump is connected to the aorta for diastolic counterpulsation. A muscle can either be wrapped around the blood pump directly, or around one of two separate muscle pouches connected to the blood pump. To facilitate surgery, a large pouch is inserted under the musculus latissimus dorsi, which is connected to a blood pump. When stimulated, the muscle will contract over the pouch compressing it and providing power to the blood pump. If it is found that the pressure generated in the pouch cannot meet the aortic blood pressure, it can be augmented by using a pressure amplifier.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Electric and pneumatic drives in an exact comparison; Elektrische und pneumatische Antriebe im exakten Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Volk, Roland [Festo AG und Co. KG, Esslingen (Germany)

    2013-04-01

    The question, whether a pneumatic drive is more energy efficient than an electric drive, is very difficult to answer straightaway. In the automation technology, the energy efficiency always depends on the respective industrial application. Only the direct comparison of an electric and pneumatic drive having the same dimension in different conceptual formulations clears up with prejudices.

  8. Efficient control of servo pneumatic actuator system utilizing by-pass ...

    Indian Academy of Sciences (India)

    The issue of energy saving nowadays is very crucial. Pneumatic systems, constituting an important segment of almost every industry, represent large energy consumers. Also, a significant problem with servo pneumatic actuators is achieving accuracy in positioning. The higher the positioning accuracy, the higher the ...

  9. Introducing PneuAct: Parametrically-Designed MRI-Compatible Pneumatic Stepper Actuator

    NARCIS (Netherlands)

    Sojoodi Farimani, F.; Misra, Sarthak

    2018-01-01

    Pneumatic stepper motors are one of the promising alternative actuation methods for motion control in environments where electromagnetic (EM) motors cannot be used. Due to the lack of commercial off-the-shelf products, researchers working on MR compatible robotics have to develop their own pneumatic

  10. Static Modeling for Commercial Braided Pneumatic Muscle Actuators

    Directory of Open Access Journals (Sweden)

    Jun Zhong

    2014-05-01

    Full Text Available An enhanced model is proposed to describe static property of commercial braided pneumatic muscle actuators by including several important influencing factors. Elasticity of elastomer tube is considered and Ogden strain energy function is employed to describe its strain energy density. During pressurized process, small deformation of fiber occurs and is calculated using force balancing principle. Frictional forces within muscles are studied, which consist of friction within braid and that between bladder and braid. Isobaric experiments are performed and results verify the validity of the model.

  11. Comparison of contractile and extensile pneumatic artificial muscles

    Science.gov (United States)

    Pillsbury, Thomas E.; Wereley, Norman M.; Guan, Qinghua

    2017-09-01

    Pneumatic artificial muscles (PAMs) are used in robotic and prosthetic applications due to their high power to weight ratio, controllable compliance, and simple design. Contractile PAMs are typically used in traditional hard robotics in place of heavy electric motors. As the field of soft robotics grows, extensile PAMs are beginning to have increased usage. This work experimentally tests, models, and compares contractile and extensile PAMs to demonstrate the advantages and disadvantages of each type of PAM and applications for which they are best suited.

  12. Investigating the grindability effect of loose material conveyed pneumatically

    Energy Technology Data Exchange (ETDEWEB)

    Bandrowski, J.; Fitka, H.; Krajzel, J.; Raczek, J.; Kaczmarzyk, G.

    1979-10-01

    Presents a mathematical analysis of the grindability effect during pneumatic conveying of coal, coke breeze and ash. Mathematical grindability models are shown. The dependence of the grindability effect of the transported material on the following factors is analyzed: diameter of the grains, speed of their flow, concentration of grains in the air within the conveying system and the conveying time. It is noted that the results of the analysis are identical with the results of investigations described in the literature. (7 refs.) (In Polish)

  13. Adaptive Tracking Control of an Electro-Pneumatic Clutch Actuator

    Directory of Open Access Journals (Sweden)

    Glenn-Ole Kaasa

    2003-10-01

    Full Text Available This paper deals with the application of a simple adaptive algorithm for robust tracking control of an electro-pneumatic clutch actuator with output feedback. We present a mathematical model of the strongly nonlinear system, and implement an adaptive algorithm, based on a parallel feedforward compensator (PFC to remove the relative-degree-1 restriction. We propose a practical method of constructing the PFC, and introduce a simple modification that removes an inherent restriction on bandwidth of the nonlinear system. We show that the adaptive algorithm deals well with nonlinearities, and we achieve tracking corresponding to a settling-time of 150 ms.

  14. Micro Tools with Pneumatic Actuators for Desktop Factories

    Directory of Open Access Journals (Sweden)

    Björn HOXHOLD

    2009-10-01

    Full Text Available This paper presents the design, the simulation and the fabrication process of two novel pneumatically driven auxiliary micro tools that can be used to improve and to speed up assembling processes in desktop factories. The described micro systems are designed to function as centrifugal feeders for small glass balls or active clamping devices with small external dimensions. They are able to deliver more than six balls per second on demand to a gripper and align and clamp single chips in a fixed position.

  15. Pneumatic rupture of the esophagus caused by carbonated drinks

    International Nuclear Information System (INIS)

    Meyerovitch, J.; Barzilay, Z.; Tel Aviv Univ.; Ben Ami, T.; Rozenman, J.; Tel Aviv Univ.

    1988-01-01

    Pneumatic rupture of the esophagus occurs when gas under pressure is accidentally delivered into the oral cavity. To the 4 cases previously described we add 2 pediatric patients and in both the source of the offending gas was a bottle of carbonated drink. The mild initial symptoms were followed in both by physical and radiographic findings suggesting pharyngoesophageal perforation. Early radiologic findings included free subcutaneous and mediastinal air, followed later by hydropneumothorax and mediastinal widening as well as leak of contrast material on gastrografin swallow. CT findings contributed to patient evaluation and management. (orig.)

  16. Flow Rate Analysis of 3/2 Directional Pneumatic Valve by Means Of Ansys Cfx Software

    Directory of Open Access Journals (Sweden)

    Slawomir BLASIAK

    2014-12-01

    Full Text Available The main purpose of this paper was to develop a selection method of the pneumatic connectors for directional 3/2 valve. The method was established to minimize resistance and loss of pressure in the valve with mounted pneumatic connections for the selected pipe diameters. Directional valve was modeled in 3D CAD software SolidWorks while 3D models of the air connections have been downloaded from the website of one of the leading suppliers of pneumatic. Based on developed solid model the simulation of compressed air flow in the software for computational fluid dynamics Ansys CFX was conducted. The studies using CFD methods helped to determine which air connections best meet the assumptions. Performed numerical tests enable proper selection of items to the newly designed pneumatic systems for a particular group of valves. As a consequence, this translates into a reduction in energy consumption and improve the efficiency of the entire pneumatic complex system.

  17. Frictional properties of lubrication greases with the addition of nickel nanoparticles in pneumatic cylinder

    Science.gov (United States)

    Chang, Ho; Lan, Chou-Wei; Guo, Jia-Bin

    2011-12-01

    This paper studies the influence of addition of 100 nm diameter nickel nano-particles on the friction properties of synthetic grease (Li base, VG100) in pneumatic cylinder. The friction force test of pneumatic cylinder equipment measures the frictional force between seal and cylinder bore in pneumatic cylinders. The lubricants with addition of nickel nano-particles were used for lubricating the contact interface between seal and cylinder bore. The friction force test equipment employ a load cell force sensor to measure the friction force between seals and cylinder bores. Results obtained from experimental tests are compared to determine the friction force between seals and cylinder bore in pneumatic cylinders. The study leads to the conclusion that the addition of nickel nano-particles to synthetic grease results in a decrease in friction force between seals and cylinder bores in pneumatic cylinder. This tribological behavior is closely related to the deposition of nano-particles on the rubbing surfaces

  18. Suboccipital neuropathy after bone conduction device placement

    NARCIS (Netherlands)

    Faber, H.T.; Ru, J.A. de

    2013-01-01

    OBJECTIVE: To describe the clinical characteristics of a 70-year-old female with occipital neuropathy following bone conduction device surgery. DESCRIPTION: A 65-year-old woman underwent bone conduction device placement surgery on the left temporal bone. Postoperatively she progressively developed

  19. Bone Signaling in Middle Ear Development: A Genome‐Wide Differential Expression Analysis

    DEFF Research Database (Denmark)

    Nielsen, Michelle Christine; Bertelsen, Tomas Martin; Friis, Morten

    2014-01-01

    Common middle ear diseases may affect bone behavior in the middle ear air cell system. To understand this pathologic pneumatization, the normal development of bone in the middle ear should be investigated. The objective of this study was to analyze gene expression of bone‐related signaling factor...... of the bulla wall. Anat Rec, 297:2349–2355, 2014. © 2014 Wiley Periodicals, Inc....

  20. Thermal analysis of wirelessly powered thermo-pneumatic micropump based on planar LC circuit

    International Nuclear Information System (INIS)

    Chee, Pei Song; Nafea, Marwan; Leow, Pei Ling; Ali, Mohamed Sultan Mohamed

    2016-01-01

    This paper studies the thermal behavior of a wireless powered micropump operated using thermo-pneumatic actuation. Numerical analysis was performed to investigate the temporal conduction of the planar inductor-capacitor (LC) wireless heater and the heating chamber. The result shows that the temperature at the heating chamber reaches steady state temperature of 46.7.deg.C within 40 seconds. The finding was further verified with experimental works through the fabrication of the planar LC heater (RF sensitive actuator) and micropump device using MEMS fabrication technique. The fabricated device delivers a minimum volume of 0.096 μL at the temperature of 29.deg.C after being thermally activated for 10 s. The volume dispensed from the micropump device can precisely controlled by an increase of the electrical heating power within the cut-off input power of 0.22 W. Beyond the power, the heat transfer to the heating chamber exhibits non-linear behavior. In addition, wireless operation of the fabricated device shows successful release of color dye when the micropump is immersed in DI-water containing dish and excited by tuning the RF power.

  1. Thermal analysis of wirelessly powered thermo-pneumatic micropump based on planar LC circuit

    Energy Technology Data Exchange (ETDEWEB)

    Chee, Pei Song; Nafea, Marwan; Leow, Pei Ling; Ali, Mohamed Sultan Mohamed [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2016-06-15

    This paper studies the thermal behavior of a wireless powered micropump operated using thermo-pneumatic actuation. Numerical analysis was performed to investigate the temporal conduction of the planar inductor-capacitor (LC) wireless heater and the heating chamber. The result shows that the temperature at the heating chamber reaches steady state temperature of 46.7.deg.C within 40 seconds. The finding was further verified with experimental works through the fabrication of the planar LC heater (RF sensitive actuator) and micropump device using MEMS fabrication technique. The fabricated device delivers a minimum volume of 0.096 μL at the temperature of 29.deg.C after being thermally activated for 10 s. The volume dispensed from the micropump device can precisely controlled by an increase of the electrical heating power within the cut-off input power of 0.22 W. Beyond the power, the heat transfer to the heating chamber exhibits non-linear behavior. In addition, wireless operation of the fabricated device shows successful release of color dye when the micropump is immersed in DI-water containing dish and excited by tuning the RF power.

  2. Pneumatic dilation and botulinum toxin: when and why?

    Science.gov (United States)

    Bozzi, Rosamaria; Di Martino, Vincenzo; Inzirillo, Antonio; D'Avenia, Eugenio; Inzirillo, Maurizio; Cattaneo, Fabio; Cattaneo, Domenico

    2013-01-01

    Pneumatic dilation and botulinum toxin:when and why? The endoscopic treatment options of achalasia include botulinum toxin (BT) injection and pneumatic dilation (PD) of the lower esophageal sphincter (LES). BT can reduce the LES pressure by blocking the release of acetylcoline from presynaptic cholinergic nerve terminals in the myenteric plexus. Although the procedure is safe and good initial response is reported, there is a wide variability in the duration of the response and the effect tends to decrease over time. BT is usually recommended for elderly patients or patients with comorbid illnesses, who are poor candidates for more invasive procedures. PD aims at tearing the muscle fibers of the LES and is considered the most effective nonsurgical treatment for achalasia. Technical details of the procedure vary in different institutions and in many clinical settings the choice between PD or minimally invasive surgical myotomy depends upon local expertise in the procedures. Further endoscopic treatment options such as submucosal esophageal myotomy or self-expanding metallic stents are being studied.

  3. Empirical modeling of dynamic behaviors of pneumatic artificial muscle actuators.

    Science.gov (United States)

    Wickramatunge, Kanchana Crishan; Leephakpreeda, Thananchai

    2013-11-01

    Pneumatic Artificial Muscle (PAM) actuators yield muscle-like mechanical actuation with high force to weight ratio, soft and flexible structure, and adaptable compliance for rehabilitation and prosthetic appliances to the disabled as well as humanoid robots or machines. The present study is to develop empirical models of the PAM actuators, that is, a PAM coupled with pneumatic control valves, in order to describe their dynamic behaviors for practical control design and usage. Empirical modeling is an efficient approach to computer-based modeling with observations of real behaviors. Different characteristics of dynamic behaviors of each PAM actuator are due not only to the structures of the PAM actuators themselves, but also to the variations of their material properties in manufacturing processes. To overcome the difficulties, the proposed empirical models are experimentally derived from real physical behaviors of the PAM actuators, which are being implemented. In case studies, the simulated results with good agreement to experimental results, show that the proposed methodology can be applied to describe the dynamic behaviors of the real PAM actuators. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  4. 3-D pneumatic seismic isolation of nuclear power plants

    International Nuclear Information System (INIS)

    Beliaev, V.S.; Vinogradov, V.V.; Kostarev, V.V.; Kuzmitchev, V.P.; Privalov, S.A.; Siro, V.A.; Krylova, I.N.; Dolgaya, A.A.; Uzdin, A.M.; Vasiliev, A.V.

    2002-01-01

    This paper describes the work carried at the Russian Federation Research Center of Fundamental Engineering (RCFE), in development of innovative pneumatic multicomponent low-frequency seismic isolation bearings for advanced nuclear power plants.This device incorporates both supporting spherical elements, which provide displacements in the horizontal direction, and pneumatic dampers with rubber diaphragms for displacement in the vertical direction. To decrease the relative displacements of the isolated object the system uses viscoelastic dampers. Damping devices had been specially elaborated for the reactor building seismic isolation system as a result of substantial advances in the design and operation of the HD-type hydrodampers, created at the CKTI VIBROSEISM. The procedures developed have been used for comparison of the test and computer data on model isolated steel structure (MISS) and isolated rigid mass (IRM) isolators produced by ENEA and KAERI. Most recent work has concentrated on the development of mathematical models of isolators and isolated nuclear structures. Force-deformation characteristics of the HDRB model had been calculated on the basis of a special method of non-linear elastic theory using the continual transformations method. (author)

  5. Development of an Air Pneumatic Suspension System for Transtibial Prostheses

    Directory of Open Access Journals (Sweden)

    Gholamhossein Pirouzi

    2014-09-01

    Full Text Available The suspension system and socket fitting of artificial limbs have major roles and vital effects on the comfort, mobility, and satisfaction of amputees. This paper introduces a new pneumatic suspension system that overcomes the drawbacks of current suspension systems in donning and doffing, change in volume during daily activities, and pressure distribution in the socket-stump interface. An air pneumatic suspension system (APSS for total-contact sockets was designed and developed. Pistoning and pressure distribution in the socket-stump interface were tested for the new APSS. More than 95% of the area between each prosthetic socket and liner was measured using a Tekscan F-Scan pressure measurement which has developed matrix-based pressure sensing systems. The variance in pressure around the stump was 8.76 kPa. APSS exhibits less pressure concentration around the stump, improved pressure distribution, easy donning and doffing, adjustability to remain fitted to the socket during daily activities, and more adaptability to the changes in stump volume. The volume changes were adjusted by utility of air pressure sensor. The vertical displacement point and reliability of suspension were assessed using a photographic method. The optimum pressure in every level of loading weight was 55 kPa, and the maximum displacement was 6 mm when 90 N of weight was loaded.

  6. Repeating pneumatic hydrogen pellet injector for plasma fueling

    International Nuclear Information System (INIS)

    Combs, S.K.; Milora, S.L.; Foust, C.R.; Foster, C.A.; Schuresko, D.D.

    1985-01-01

    A repeating pneumatic pellet injector has been developed for plasma fueling applications. The repetitive device extends pneumatic injector operation to steady state. The active mechanism consists of an extruder and a gun assembly that are cooled by flowing liquid-helium refrigerant. The extruder provides a continuous supply of solid hydrogen to the gun assembly, where a reciprocating gun barrel forms and chambers cylindrical pellet from the extrusion; pellets are then accelerated with compressed hydrogen gas (pressures up to 125 bar) to velocities -1 have been obtained with 2.1- , 3.4- , and 4.0-mm-diameter pellets. The present apparatus operates at higher firing rates in short bursts; for example, a rate of 6 s -1 for 2 s with the larger pellets. These pellet parameters are in the range applicable for fueling large present-day fusion devices such as the Tokamak Fusion Test Reactor (TFTR). Experimental results are presented, including effects of propellant pressure and barrel length on gun performance

  7. MarsVac: Pneumatic Sampling System for Planetary Exploration

    Science.gov (United States)

    Zacny, K.; Mungas, G.; Chu, P.; Craft, J.; Davis, K.

    2008-12-01

    We are proposing a Mars Sample Return scheme whereby a sample of regolith is acquired directly into a Mars Ascent Vehicle using a pneumatic system. Unlike prior developments that used suction to collect fines, the proposed system uses positive pressure to move the regolith. We envisage 3 pneumatic tubes to be embedded inside the 3 legs of the lander. Upon landing, the legs will burry themselves into the regolith and the tubes will fill up with regolith. With one puff of gas, the regolith can be lifted into a sampling chamber onboard of the Mars Ascent Vehicle. An additional chamber can be opened to acquire atmospheric gas and dust. The entire MSR will require 1) an actuator to open/close sampling chamber and 2) a valve to open gas cylinder. In the most recent study related to lunar excavation and funded under the NASA SBIR program we have shown that it is possible lift over 3000 grams of soil with only 1 gram of gas at 1atm. Tests conducted under Mars atmospheric pressure conditions (5 torr). In September of 2008, we will be performing tests at 1/6thg (Moon) and 1/3g (Mars) to determine mass lifting efficiencies in reduced gravities.

  8. Pneumatic oscillator circuits for timing and control of integrated microfluidics.

    Science.gov (United States)

    Duncan, Philip N; Nguyen, Transon V; Hui, Elliot E

    2013-11-05

    Frequency references are fundamental to most digital systems, providing the basis for process synchronization, timing of outputs, and waveform synthesis. Recently, there has been growing interest in digital logic systems that are constructed out of microfluidics rather than electronics, as a possible means toward fully integrated laboratory-on-a-chip systems that do not require any external control apparatus. However, the full realization of this goal has not been possible due to the lack of on-chip frequency references, thus requiring timing signals to be provided from off-chip. Although microfluidic oscillators have been demonstrated, there have been no reported efforts to characterize, model, or optimize timing accuracy, which is the fundamental metric of a clock. Here, we report pneumatic ring oscillator circuits built from microfluidic valves and channels. Further, we present a compressible-flow analysis that differs fundamentally from conventional circuit theory, and we show the utility of this physically based model for the optimization of oscillator stability. Finally, we leverage microfluidic clocks to demonstrate circuits for the generation of phase-shifted waveforms, self-driving peristaltic pumps, and frequency division. Thus, pneumatic oscillators can serve as on-chip frequency references for microfluidic digital logic circuits. On-chip clocks and pumps both constitute critical building blocks on the path toward achieving autonomous laboratory-on-a-chip devices.

  9. Multi Objective Optimization Using Genetic Algorithm of a Pneumatic Connector

    Science.gov (United States)

    Salaam, HA; Taha, Zahari; Ya, TMYS Tuan

    2018-03-01

    The concept of sustainability was first introduced by Dr Harlem Brutland in the 1980’s promoting the need to preserve today’s natural environment for the sake of future generations. Based on this concept, John Elkington proposed an approach to measure sustainability known as Triple Bottom Line (TBL). There are three evaluation criteria’s involved in the TBL approach; namely economics, environmental integrity and social equity. In manufacturing industry the manufacturing costs measure the economic sustainability of a company in a long term. Environmental integrity is a measure of the impact of manufacturing activities on the environment. Social equity is complicated to evaluate; but when the focus is at the production floor level, the production operator health can be considered. In this paper, the TBL approach is applied in the manufacturing of a pneumatic nipple hose. The evaluation criteria used are manufacturing costs, environmental impact, ergonomics impact and also energy used for manufacturing. This study involves multi objective optimization by using genetic algorithm of several possible alternatives for material used in the manufacturing of the pneumatic nipple.

  10. Pneumatic distension of ventricular mural architecture validated histologically

    Energy Technology Data Exchange (ETDEWEB)

    Burg, M.C.; Heindel, W. [University Hospital Muenster (Germany). Dept. of Clinical Radiology; Lunkenheimer, P. [University Hospital Muenster (Germany). Dept. of Experimental Thoraco-vascular Surgery; Niederer, P. [ETH and University of Zuerich (Switzerland). Inst. for Biomedical Engineering; Brune, C. [Twente Univ. (Netherlands). Dept. of Applied Mathematics; Redmann, K. [University Hospital Muenster (Germany). Center for Reproductive Medicine and Andrology; Smerup, M. [Aarhus University Hospital (Denmark). Dept. of Cardiothoracic and Vascular Surgery; Spiegel, U.; Becker, F. [University Hospital Muenster (Germany). Dept. Surgical Research; Maintz, D. [University Hospital Muenster (Germany). Dept. of Clinical Radiology; Cologne Univ. (Germany). Dept. of Radiology; Anderson, R.H. [Newcastle Univ., London (United Kingdom). Inst. of Genetic Medicine

    2016-11-15

    There are ongoing arguments as to how cardiomyocytes are aggregated together within the ventricular walls. We used pneumatic distension through the coronary arteries to exaggerate the gaps between the aggregated cardiomyocytes, analyzing the pattern revealed using computed tomography, and validating our findings by histology. We distended 10 porcine hearts, arresting 4 in diastole by infusion of cardioplegic solutions, and 4 in systole by injection of barium chloride. Mural architecture was revealed by computed tomography, measuring also the angulations of the long chains of cardiomyocytes. We prepared the remaining 2 hearts for histology by perfusion with formaldehyde. Increasing pressures of pneumatic distension elongated the ventricular walls, but produced insignificant changes in mural thickness. The distension exaggerated the spaces between the aggregated cardiomyocytes, compartmenting the walls into epicardial, central, and endocardial regions, with a feathered arrangement of transitions between them. Marked variation was noted in the thicknesses of the parts in the different ventricular segments, with no visible anatomical boundaries between them. Measurements of angulations revealed intruding and extruding populations of cardiomyocytes that deviated from a surface-parallel alignment. Scrolling through the stacks of tomographic images revealed marked spiraling of the aggregated cardiomyocytes when traced from base to apex. Our findings call into question the current assumption that cardiomyocytes are uniformly aggregated together in a tangential fashion. There is marked heterogeneity in the architecture of the different ventricular segments, with the aggregated units never extending in a fully transmural fashion.

  11. Pneumatic distension of ventricular mural architecture validated histologically

    International Nuclear Information System (INIS)

    Burg, M.C.; Heindel, W.; Lunkenheimer, P.; Niederer, P.; Brune, C.; Redmann, K.; Smerup, M.; Spiegel, U.; Becker, F.; Maintz, D.; Cologne Univ.; Anderson, R.H.

    2016-01-01

    There are ongoing arguments as to how cardiomyocytes are aggregated together within the ventricular walls. We used pneumatic distension through the coronary arteries to exaggerate the gaps between the aggregated cardiomyocytes, analyzing the pattern revealed using computed tomography, and validating our findings by histology. We distended 10 porcine hearts, arresting 4 in diastole by infusion of cardioplegic solutions, and 4 in systole by injection of barium chloride. Mural architecture was revealed by computed tomography, measuring also the angulations of the long chains of cardiomyocytes. We prepared the remaining 2 hearts for histology by perfusion with formaldehyde. Increasing pressures of pneumatic distension elongated the ventricular walls, but produced insignificant changes in mural thickness. The distension exaggerated the spaces between the aggregated cardiomyocytes, compartmenting the walls into epicardial, central, and endocardial regions, with a feathered arrangement of transitions between them. Marked variation was noted in the thicknesses of the parts in the different ventricular segments, with no visible anatomical boundaries between them. Measurements of angulations revealed intruding and extruding populations of cardiomyocytes that deviated from a surface-parallel alignment. Scrolling through the stacks of tomographic images revealed marked spiraling of the aggregated cardiomyocytes when traced from base to apex. Our findings call into question the current assumption that cardiomyocytes are uniformly aggregated together in a tangential fashion. There is marked heterogeneity in the architecture of the different ventricular segments, with the aggregated units never extending in a fully transmural fashion.

  12. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  13. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  14. The petrous bone

    DEFF Research Database (Denmark)

    Jørkov, Marie Louise Schjellerup; Heinemeier, Jan; Lynnerup, Niels

    2009-01-01

    Intraskeletal variation in the composition of carbon (delta(13)C) and nitrogen (delta(15)N) stable isotopes measured in collagen is tested from various human bones and dentine. Samples were taken from the femur, rib, and petrous part of the temporal bone from well-preserved skeletons of both adults...... (n = 34) and subadults (n = 24). Additional samples of dentine from the root of 1st molars were taken from 16 individuals. The skeletal material is from a medieval cemetery (AD 1200-1573) in Holbaek, Denmark. Our results indicate that the petrous bone has an isotopic signal that differs significantly...... from that of femur and rib within the single skeleton (P bone and the 1st molar. The intraskeletal variation may reflect differences...

  15. Dynamic Friction Performance of a Pneumatic Cylinder with Al2O3 Film on Cylinder Surface.

    Science.gov (United States)

    Chang, Ho; Lan, Chou-Wei; Wang, Hao-Xian

    2015-11-01

    A friction force system is proposed for accurately measuring friction force and motion properties produced by reciprocating motion of piston in a pneumatic cylinder. In this study, the proposed system is used to measure the effects of lubricating greases of different viscosities on the friction properties of pneumatic cylinder, and improvement of stick-slip motion for the cylinder bore by anodizing processes. A servo motor-driven ball screw is used to drive the pneumatic cylinder to be tested and to measure the change in friction force of the pneumatic cylinder. Experimental results show, that under similar test conditions, the lubricating grease with viscosity VG100 is best suited for measuring reciprocating motion of the piston of pneumatic cylinder. The wear experiment showed that, in the Al2O3 film obtained at a preset voltage 40 V in the anodic process, the friction coefficient and hardness decreased by 55% and increased by 274% respectively, thus achieving a good tribology and wear resistance. Additionally, the amplitude variation in the friction force of the pneumatic cylinder wall that received the anodizing treatment was substantially reduced. Additionally, the stick-slip motion of the pneumatic cylinder during low-speed motion was substantially improved.

  16. The qualitative assessment of pneumatic actuators operation in terms of vibration criteria

    Science.gov (United States)

    Hetmanczyk, M. P.; Michalski, P.

    2015-11-01

    The work quality of pneumatic actuators can be assessed in terms of multiple criteria. In the case of complex systems with pneumatic actuators retained at end positions (with occurrence of piston impact in cylinder covers) the vibration criteria constitute the most reliable indicators. The paper presents an impact assessment on the operating condition of the rodless pneumatic cylinder regarding to selected vibrational symptoms. On the basis of performed analysis the authors had shown meaningful premises allowing an evaluation of the performance and tuning of end position damping piston movement with usage the most common diagnostic tools (portable vibration analyzers). The presented method is useful in tuning of parameters in industrial conditions.

  17. Vascularised endosteal bone tissue in armoured sauropod dinosaurs.

    Science.gov (United States)

    Chinsamy, Anusuya; Cerda, Ignacio; Powell, Jaime

    2016-04-26

    The presence of well-vascularised, endosteal bone in the medullary region of long bones of nonavian dinosaurs has been invoked as being homologous to medullary bone, a specialised bone tissue formed during ovulation in birds. However, similar bone tissues can result as a pathological response in modern birds and in nonavian dinosaurs, and has also been reported in an immature nonavian dinosaur. Here we report on the occurrence of well-vascularised endosteally formed bone tissue in three skeletal elements of armoured titanosaur sauropods from the Upper Cretaceous of Argentina: i) within the medullary cavity of a metatarsal, ii) inside a pneumatic cavity of a posterior caudal vertebra, iii) in intra-trabecular spaces in an osteoderm. We show that considering the criteria of location, origin (or development), and histology, these endosteally derived tissues in the saltasaurine titanosaurs could be described as either medullary bone or pathological bone. Furthermore, we show that similar endosteally formed well-vascularised bone tissue is fairly widely distributed among nondinosaurian Archosauriformes, and are not restricted to long bones, but can occur in the axial, and dermal skeleton. We propose that independent evidence is required to verify whether vascularised endosteal bone tissues in extinct archosaurs are pathological or reproductive in nature.

  18. A novel dynamic cardiac simulator utilizing pneumatic artificial muscle.

    Science.gov (United States)

    Liu, Hao; Yan, Jie; Zhou, Yuanyuan; Li, Hongyi; Li, Changji

    2013-01-01

    With the development of methods and skills of minimally invasive surgeries, equipments for doctors' training and practicing are in high demands. Especially for the cardiovascular surgeries, operators are requested to be familiar with the surgical environment of a beating heart. In this paper, we present a new dynamic cardiac simulator utilizing pneumatic artificial muscle to realize heartbeat. It's an artificial left ventricular of which the inner chamber is made of thermoplastic elastomers (TPE) with an anatomical structure of the real human heart. It is covered by another layer of material forming the artificial muscle which actuates the systole and diastole uniformly and omnidirectionally as the cardiac muscle does. Preliminary experiments were conducted to evaluate the performance of the simulator. The results indicated that the pressure at the terminal of the aorta could be controlled within the range of normal human systolic pressure, which quantitatively validated the new actuating mode of the heart-beating is effective.

  19. Design of a biped robot actuated by pneumatic artificial muscles.

    Science.gov (United States)

    Liu, Yixiang; Zang, Xizhe; Liu, Xinyu; Wang, Lin

    2015-01-01

    High compliant legs are essential for the efficient versatile locomotion and shock absorbency of humans. This study proposes a biped robot actuated by pneumatic artificial muscles to mimic human locomotion. On the basis of the musculoskeletal architecture of human lower limbs, each leg of the biped robot is modeled as a system of three segments, namely, hip joint, knee joint, and ankle joint, and eleven muscles, including both monoarticular and biarticular muscles. Each rotational joint is driven by a pair of antagonistic muscles, enabling joint compliance to be tuned by operating the pressure inside the muscles. Biarticular muscles play an important role in transferring power between joints. Walking simulations verify that biarticular muscles contribute to joint compliance and can absorb impact energy when the robot makes an impact upon ground contact.

  20. Research on Dynamic Parameters and Position Accuracy of Pneumatics Muscles

    Directory of Open Access Journals (Sweden)

    Edvard Sadovskij

    2012-12-01

    Full Text Available The article deals with pneumatic muscle MAS-20-200N-AA-MC-O, its dynamic properties and positioning accuracy as well as overviews experimental and theoretical works. The paper introduces the diagrams of vibration acceleration, discusses displacement dependence on pressure and load and presents a diagram of speed dependence on operating pressure. Vibroacceleration has been measured employing two accelerometers. Measurements have been carried out in three mutually perpendicular directions: x, y and z. The most important one is direction z, because this way the muscle performs a valuable displacement along the axis of the muscle, since this direction is the movement of the working muscle.Article in Lithuanian

  1. Research on Dynamic Parameters and Position Accuracy of Pneumatics Muscles

    Directory of Open Access Journals (Sweden)

    Edvard Sadovskij

    2013-02-01

    Full Text Available The article deals with pneumatic muscle MAS-20-200N-AA-MC-O, its dynamic properties and positioning accuracy as well as overviews experimental and theoretical works. The paper introduces the diagrams of vibration acceleration, discusses displacement dependence on pressure and load and presents a diagram of speed dependence on operating pressure. Vibroacceleration has been measured employing two accelerometers. Measurements have been carried out in three mutually perpendicular directions: x, y and z. The most important one is direction z, because this way the muscle performs a valuable displacement along the axis of the muscle, since this direction is the movement of the working muscle.Article in Lithuanian

  2. Preliminary measurements on heat balance in pneumatic tires

    Science.gov (United States)

    Nybakken, G. H.; Collart, D. Y.; Staples, R. J.; Lackey, J. I.; Clark, S. K.; Dodge, R. N.

    1973-01-01

    A variety of tests was undertaken to determine the nature of heat generation associated with a pneumatic tire operating under various conditions. Tests were conducted to determine the magnitude and distribution of internally generated heat caused by hysteresis in the rubber and ply fabric in an automobile tire operating under conditions of load, pressure, and velocity representative of normal operating conditions. These included tests at various yaw angles and tests with braking applied. In other tests, temperature sensors were mounted on a road to measure the effect of a tire rolling over and an attempt was made to deduce the magnitude and nature of interfacial friction from the resulting information. In addition, tests were performed using the scratch plate technique to determine the nature of the motion between the tire and road. Finally, a model tire was tested on a roadwheel, the surface covering which could be changed, and an optical pyrometer was used to measure rubber surface temperatures.

  3. Endoscope-guided pneumatic dilation for treatment of esophageal achalasia

    Science.gov (United States)

    Chuah, Seng-Kee; Wu, Keng-Liang; Hu, Tsung-Hui; Tai, Wei-Chen; Changchien, Chi-Sin

    2010-01-01

    Pneumatic dilation (PD) is considered to be the first line nonsurgical therapy for achalasia. The principle of the procedure is to weaken the lower esophageal sphincter by tearing its muscle fibers by generating radial force. The endoscope-guided procedure is done without fluoroscopic control. Clinicians usually use a low-compliance balloon such as Rigiflex dilator to perform endoscope-guided PD for the treatment of esophageal achalasia. It has the advantage of determining mucosal injury during the dilation process, so that a repeat endoscopy is not needed to assess the mucosal tearing. Previous studies have shown that endoscope-guided PD is an efficient and safe nonsurgical therapy with results that compare well with other treatment modalities. Although the results may be promising, long-term follow-up is required in the near future. PMID:20101764

  4. Design of pneumatic proportional flow valve type 5/3

    Science.gov (United States)

    Laski, P. A.; Pietrala, D. S.; Zwierzchowski, J.; Czarnogorski, K.

    2017-08-01

    In this paper the 5/3-way pneumatic, proportional flow valve was designed and made. Stepper linear actuator was used to move the spool. The valve is controlled by the controlled based on a AVR microcontroller. Virtual model of the valve was created in CAD. The real element was made based on a standard 5/3-way manually actuated valve with hand lever, which was dismounted and replaced by linear stepper motor. All the elements was mounted in a specially made housing. The controller consists of microcontroller Atmega16, integrated circuit L293D, display, two potentiometers, three LEDs and six buttons. Series of research was also conducted. Simulation research were performed using CFD by the Flow Simulation addition to SolidWorks. During the experiments the valve characteristics of flow and pressure was determined.

  5. Bubble inductors: Pneumatic tuning of a stretchable inductor

    Science.gov (United States)

    Lazarus, Nathan; Bedair, Sarah S.

    2018-05-01

    From adaptive matching networks in power systems to channel selectable RF filters and circuitry, tunable inductors are fundamental components for circuits requiring reconfigurability. Here we demonstrate a new continuously tunable inductor based on physically stretching the inductor traces themselves. Liquid-metal-based stretchable conductors are wrapped around a pneumatic bubble actuator, allowing the inductor to be collapsed or expanded by application of pressure. In vacuum the bubble collapses, bringing the loop area to nearly zero, while positive pressure brings a dramatic increase in area and loop inductance. Using this approach, the inductor demonstrated in this work was able to achieve a tuning ratio of 2.6 with 1-2 second response time. With conductors available that can stretch by hundreds of percent, this technique is promising for very large tuning ratios in continuously tunable inductors.

  6. Functional design of heat exchange for pneumatic vehicles

    Science.gov (United States)

    Xu, Z. G.; Yang, D. Y.; Shen, W. D.; Liu, T. T.

    2017-10-01

    With the increasingly serious environmental problems, especially the impact of fog and haze, the development of air powered vehicles has become an important research direction of new energy vehicles. Quadrature test was done with different materials, i.e. stainless steel and aluminum alloy, at different inlet pressures, using different expansion gases, i.e. air, CO2, for heat exchanging properties for pneumatic vehicles. The mathematics as well as simulation methods are used to analyze the different heat exchanging effects in the multistage cylinder. The research results showed that the stainless steel has better effects in heat exchanging than Aluminum Alloy; the intake pressure has little effect on CO2 than the air in heat exchanging effect. CO2 is better in heat exchanging than air.

  7. Pneumatic injector of deuterium macroparticles for TORE-SUPRA tokamak

    International Nuclear Information System (INIS)

    Vinyar, I.V.; Umov, A.P.; Lukin, A.Ya.; Skoblikov, S.V.; Reznichenko, P.V.; Krasil'nikov, I.A.

    2006-01-01

    The pneumatic injector for periodic injection of fuel-solid-deuterium pellets into the plasma of the TORE-SUPRA tokamak in a steady-state mode is described. The deuterium pellet injection with an unlimited duration is ensured by a screw extruder in which gaseous deuterium is frozen and squeezed outwards in the form of a rod with a rectangular cross section. A cutter installed on the injector's barrel cuts a cylinder with a diameter of 2 mm and a length of 1.0-3.5 mm out from this rod. The movement of the cutter is controlled by a pulsed electromagnetic drive at a pulse repetition rate of 10 Hz. In the injector's barrel, a compressed gas accelerates a deuterium pellet to a velocity of 100-650 m/s [ru

  8. Temporal networks

    CERN Document Server

    Saramäki, Jari

    2013-01-01

    The concept of temporal networks is an extension of complex networks as a modeling framework to include information on when interactions between nodes happen. Many studies of the last decade examine how the static network structure affect dynamic systems on the network. In this traditional approach  the temporal aspects are pre-encoded in the dynamic system model. Temporal-network methods, on the other hand, lift the temporal information from the level of system dynamics to the mathematical representation of the contact network itself. This framework becomes particularly useful for cases where there is a lot of structure and heterogeneity both in the timings of interaction events and the network topology. The advantage compared to common static network approaches is the ability to design more accurate models in order to explain and predict large-scale dynamic phenomena (such as, e.g., epidemic outbreaks and other spreading phenomena). On the other hand, temporal network methods are mathematically and concept...

  9. Evaluation of Effective Diaphragm Area for Pneumatic Actuator

    International Nuclear Information System (INIS)

    Ryu, Hogeun; Han, Bongsub; Seon, Juhyoung

    2016-01-01

    The purpose of this study is to develop a methodology to calculate the exact effective diaphragm area using the results of diagnostic test to be performed in the evaluation of air operated valve performance. By using this developed methodology in pneumatic actuator performance evaluation, it can be reduce the possible errors arising from effective diaphragm area in the evaluation of performance of air operated valves. The performance assessment for the operability and structural integrity of air operated valves for the domestic nuclear power plant is in progress. One of the important parameters that determine the performance of the air operated valves is the effective diaphragm area of diaphragm type actuator. The effective diaphragm area is the actual area which the air pressure acting on the diaphragm. In general, the effective diaphragm area used for the performance evaluation of pneumatic actuator is provided by the manufacture or the actuator drawing. Flat type diaphragm was showed the difference between the measured value of EDA and the manufacture’s value, in the case of convoluted type diaphragm has showed that the measured value of EDA and manufacture’s value is almost the same. When evaluate a performance of a diaphragm actuator, accurate EDA is to be used because it is an important variable affecting the actuator performance. Particularly in the case of flat type diaphragm which EDA is changed in accordance with the stroke position, by using the EDA evaluation methodology developed in this study to minimize a possible error due to EDA when evaluating the performance of the air actuator

  10. Analysis of nonlinear elastic behavior in miniature pneumatic artificial muscles

    Science.gov (United States)

    Hocking, Erica G.; Wereley, Norman M.

    2013-01-01

    Pneumatic artificial muscles (PAMs) are well known for their excellent actuator characteristics, including high specific work, specific power, and power density. Recent research has focused on miniaturizing this pneumatic actuator technology in order to develop PAMs for use in small-scale mechanical systems, such as those found in robotic or aerospace applications. The first step in implementing these miniature PAMs was to design and characterize the actuator. To that end, this study presents the manufacturing process, experimental characterization, and analytical modeling of PAMs with millimeter-scale diameters. A fabrication method was developed to consistently produce low-cost, high performance, miniature PAMs using commercially available materials. The quasi-static behavior of these PAMs was determined through experimentation on a single actuator with an active length of 39.16 mm (1.54 in) and a diameter of 4.13 mm (0.1625 in). Testing revealed the PAM’s full evolution of force with displacement for operating pressures ranging from 207 to 552 kPa (30-80 psi in 10 psi increments), as well as the blocked force and free contraction at each pressure. Three key nonlinear phenomena were observed: nonlinear PAM stiffness, hysteresis of the force versus displacement response for a given pressure, and a pressure deadband. To address the analysis of the nonlinear response of these miniature PAMs, a nonlinear stress versus strain model, a hysteresis model, and a pressure bias are introduced into a previously developed force balance analysis. Parameters of these nonlinear model refinements are identified from the measured force versus displacement data. This improved nonlinear force balance model is shown to capture the full actuation behavior of the miniature PAMs at each operating pressure and reconstruct miniature PAM response with much more accuracy than previously possible.

  11. Analysis of nonlinear elastic behavior in miniature pneumatic artificial muscles

    International Nuclear Information System (INIS)

    Hocking, Erica G; Wereley, Norman M

    2013-01-01

    Pneumatic artificial muscles (PAMs) are well known for their excellent actuator characteristics, including high specific work, specific power, and power density. Recent research has focused on miniaturizing this pneumatic actuator technology in order to develop PAMs for use in small-scale mechanical systems, such as those found in robotic or aerospace applications. The first step in implementing these miniature PAMs was to design and characterize the actuator. To that end, this study presents the manufacturing process, experimental characterization, and analytical modeling of PAMs with millimeter-scale diameters. A fabrication method was developed to consistently produce low-cost, high performance, miniature PAMs using commercially available materials. The quasi-static behavior of these PAMs was determined through experimentation on a single actuator with an active length of 39.16 mm (1.54 in) and a diameter of 4.13 mm (0.1625 in). Testing revealed the PAM’s full evolution of force with displacement for operating pressures ranging from 207 to 552 kPa (30–80 psi in 10 psi increments), as well as the blocked force and free contraction at each pressure. Three key nonlinear phenomena were observed: nonlinear PAM stiffness, hysteresis of the force versus displacement response for a given pressure, and a pressure deadband. To address the analysis of the nonlinear response of these miniature PAMs, a nonlinear stress versus strain model, a hysteresis model, and a pressure bias are introduced into a previously developed force balance analysis. Parameters of these nonlinear model refinements are identified from the measured force versus displacement data. This improved nonlinear force balance model is shown to capture the full actuation behavior of the miniature PAMs at each operating pressure and reconstruct miniature PAM response with much more accuracy than previously possible. (paper)

  12. Comparison of Pneumatic, Ultrasonic and Combination Lithotripters in Percutaneous Nephrolithotripsy

    Directory of Open Access Journals (Sweden)

    Kursad Zengin

    2014-10-01

    Full Text Available Purpose We aimed to compare the outcomes of pneumatic (PL, ultrasonic (UL and combined (PL/UL lithotripsy performed in percutaneous lithotripsy (PNL according to success rates and stone clearence. Materials and Methods The medical records of 512 patients treated with PNL between April 2010 and April 2013 were evaluated. Postoperative stone analysis revealed as calcium oxalate in 408 of these patients. The operation notes of 355 patients recorded in detail with complete parameters were reviewed. According to stone disintegration method, patients were divided into three groups: PL only in Group I, UL only in Group II, and UL/PL combination in Group III. Number of patients was 155, 110 and 90, respectively. Results Fluoroscopy screening time was significantly shorter in group II, and III compared to group I (p<0.001. The failure rates were 13.5% (21 patients for group I, 3.6% (4 patients for group II, and 3.3% (3 patients for group III. There was a significant statistical difference in favor of group II and III by means of success (p=0.023. Group II and III had larger FSA, and this was statistically significant (p=0.032. Stone disintegration time (SDT was 64.0±41.92 minutes for group I, 49.5±34.63 for group II, and 37.7±16.89 for group III. Group III has a statistically significant shorter SDT (p=0.011. Conclusions We concluded that, in cases with high stone burden, where faster and efficient lithotripsy is needed, combined ultrasonic / pneumatic lithotripter may be the ideal choice and in suitable cases ultrasonic lithotripter usage provides important advantages to the surgeon.

  13. A pneumatic transfer system for special form 252Cf

    International Nuclear Information System (INIS)

    Gehrke, R.J.; Berry, S.M.; Grafwallner, E.G.; Hoggan, J.M.

    1996-09-01

    A pneumatic transfer system has been developed for use with series 100 Special Form 252 Cf. It was developed to reduce the exposure to personnel handling sources of 252 Cf with masses up to 150 microg by permitting remotely activated two-way transfer between the storage container and the irradiation position. The pneumatic transfer system also permits transfers for reproducible repetitive irradiation periods. In addition to the storage container equipped with quick-release fittings, the transfer system consists of an irradiation station, a control box with momentary contact switches to activate the air-pressure control valves and indicators to identify the location of the source, and connecting air hose and electrical wire. A source of 20 psig air and 110 volt electrical power are required for operation of the transfer system which can be easily moved and set up by one individual in 5 to 10 minutes. Tests have shown that rarely does a source become lodged in the transfer tubing, but two methods have been developed to handle incomplete transfers of the 252 Cf source. The first method consists of closing one air vent to allow a pressure impulse to propel the source to the opposite side. The second method applies to those 252 Cf capsules with a threaded or tapped end to which a small ferromagnetic piece can be attached; an incompletely transferred source in the transfer tube can then be guided to a position of safety by surrounding the transfer tubing containing the capsule with a horseshoe magnet attached to the end of a long pole

  14. Validity and reliability of a controlled pneumatic resistance exercise device.

    Science.gov (United States)

    Paulus, David C; Reynolds, Michael C; Schilling, Brian K

    2008-01-01

    During the concentric portion of the free-weight squat exercise, accelerating the mass from rest results in a fluctuation in ground reaction force. It is characterized by an initial period of force greater than the load while accelerating from rest followed by a period of force lower than the external load during negative acceleration. During the deceleration phase, less force is exerted and muscles are loaded sub-optimally. Thus, using a reduced inertia form of resistance such as pneumatics has the capability to minimize these inertial effects as well as control the force in real time to maximize the force exerted over the exercise cycle. To improve the system response of a preliminary design, a squat device was designed with a reduced mass barbell and two smaller pneumatic cylinders. The resistance was controlled by regulating cylinder pressure such that it is capable of adjusting force within a repetition to maximize force exerted during the lift. The resistance force production of the machine was statically validated with the input voltage and output force R2 =0.9997 for at four increments of the range of motion, and the intraclass correlation coefficient (ICC) between trials at the different heights equaled 0.999. The slew rate at three forces was 749.3 N/s +/- 252.3. Dynamic human subject testing showed the desired input force correlated with average and peak ground reaction force with R2 = 0.9981 and R2 = 0.9315, respectively. The ICC between desired force and average and peak ground reaction force was 0.963. Thus, the system is able to deliver constant levels of static and dynamic force with validity and reliability. Future work will be required to develop the control strategy required for real-time control, and performance testing is required to determine its efficacy.

  15. Pneumatic strength assessment device: design and isometric measurement.

    Science.gov (United States)

    Paulus, David C; Reiser, Raoul F; Troxell, Wade O

    2004-01-01

    In order to load a muscle optimally during resistance exercise, it should be heavily taxed throughout the entire range of motion for that exercise. However, traditional constant resistance squats only tax the lower-extremity muscles to their limits at the "sticking region" or a critical joint configuration of the exercise cycle. Therefore, a linear motion (Smith) exercise machine was modified with pneumatics and appropriate computer control so that it could be capable of adjusting force to control velocity within a repetition of the squat exercise or other exercise performed with the device. Prior to application of this device in a dynamic squat setting, the maximum voluntary isometric force (MVIF) produced over a spectrum of knee angles is needed. This would reveal the sticking region and overall variation in strength capacity. Five incremental knee angles (90, 110, 130, 150, and 170 degrees, where 180 degrees defined full extension) were examined. After obtaining university-approved informed consent, 12 men and 12 women participated in the study. The knee angle was set, and the pneumatic cylinder was pressurized such that the subject could move the barbell slightly but no more than two-centimeters. The peak pressure exerted over a five-second maximum effort interval was recorded at each knee angle in random order and then repeated. The average of both efforts was then utilized for further analysis. The sticking region occurred consistently at a 90 degrees knee angle, however, the maximum force produced varied between 110 degrees and 170 degrees with the greatest frequency at 150 degrees for both men and women. The percent difference between the maximum and minimum MVIF was 46% for men and 57% for women.

  16. Characterization of graphite dust produced by pneumatic lift

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Ke [Guangdong Provincial Key Laboratory of Thermal Management Engineering and Materials, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, Guangdong (China); Peng, Wei; Liu, Bing [Institute of Nuclear and New Energy Technology of Tsinghua University, Advanced Nuclear Energy Technology Cooperation Innovation Center, The Key Laboratory of Advanced Nuclear Engineering and Safety, Ministry of Education, Beijing 100084 (China); Kang, Feiyu [Guangdong Provincial Key Laboratory of Thermal Management Engineering and Materials, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, Guangdong (China); Yang, Xiaoyong; Li, Weihua [Institute of Nuclear and New Energy Technology of Tsinghua University, Advanced Nuclear Energy Technology Cooperation Innovation Center, The Key Laboratory of Advanced Nuclear Engineering and Safety, Ministry of Education, Beijing 100084 (China); Yu, Suyuan, E-mail: suyuan@tsinghua.edu.cn [Center for Combustion Energy, The Key Laboratory for Thermal Science and Power Engineering, Ministry of Educations, Tsinghua University, Beijing 100084 (China)

    2016-08-15

    Highlights: • Generation of graphite dust by pneumatic lift. • Determination of morphology and particle size distribution of graphite dust. • The size of graphite dust in this study is compared to AVR and THTR-300 results. • Graphite dust originates from both filler and binder of the matrix graphite. - Abstract: Graphite dust is an important safety concern of high-temperature gas-cooled reactor (HTR). The graphite dust could adsorb fission products, and the radioactive dust is transported by the coolant gas and deposited on the surface of the primary loop. The simulation of coagulation, aggregation, deposition, and resuspension behavior of graphite dust requires parameters such as particle size distribution and particle shape, but currently very limited data on graphite dust is available. The only data we have are from AVR and THTR-300, however, the AVR result is likely to be prejudiced by the oil ingress. In pebble-bed HTR, graphite dust is generally produced by mechanical abrasion, in particular, by the abrasion of graphite pebbles in the lifting pipe of the fuel handling system. Here we demonstrate the generation and characterization of graphite dust that were produced by pneumatic lift. This graphite dust could substitute the real dust in HTR for characterization. The dust, exhibiting a lamellar morphology, showed a number-weighted average particle size of 2.38 μm and a volume-weighted average size of 14.62 μm. These two sizes were larger than the AVR and THTR results. The discrepancy is possibly due to the irradiation effect and prejudice caused by the oil ingress accident. It is also confirmed by the Raman spectrum that both the filler particle and binder contribute to the dust generation.

  17. Effective dose at pneumatic reduction of paediatric intussusception

    International Nuclear Information System (INIS)

    Heenan, S.D.; Kyriou, J.; Fitzgerald, M.; Adam, E.J.

    2000-01-01

    AIM: The purpose of this study was to assess screening times and resulting dose implication at pneumatic reduction of intussusception in the paediatric age group and to examine the relationship with the outcome of the procedure. MATERIALS AND METHODS: We retrospectively reviewed the case notes and departmental records of 143 children who had undergone a total of 153 pneumatic reductions in our department over a 4-year period. Success rates, screening times and available dose-area products (DAP) were recorded. The DAPs were converted to effective dose (ED) for 77 procedures. RESULTS: A 76.5% (117/153) success rate was achieved with a recurrence rate of 6.5% and only one complication: a perforation. Screening times were recorded in 137 reductions and ranged from 15 s to 22.6 min. Although the longest screening time was associated with an unsuccessful outcome, the second longest time of 21 min was successful. This gave a DAP of 1278 cGy cm 2 and an ED of 12.73 mSv, which is equivalent to approximately 400 abdominal films for a 1-year-old. A lifetime risk of fatal cancer of one in 1000 was achieved, assuming the worst case, after a screening time of 30 min on our conventional fluoroscopy unit. CONCLUSION: Our success rate compares well with other centres. Our institution is a tertiary referral centre and the occasional long screening time may reflect the delay and complex nature of the patients referred. Persistence at air reduction may be successful and the success rate increases with delayed attempts but the risks of the increasing radiation burden must be weighed against the risks of emergency surgery and anaesthesia. Heenan, S.D. (2000)

  18. Evaluation of Effective Diaphragm Area for Pneumatic Actuator

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Hogeun; Han, Bongsub; Seon, Juhyoung [SOOSAN INDUSTRIES, Seoul (Korea, Republic of)

    2016-10-15

    The purpose of this study is to develop a methodology to calculate the exact effective diaphragm area using the results of diagnostic test to be performed in the evaluation of air operated valve performance. By using this developed methodology in pneumatic actuator performance evaluation, it can be reduce the possible errors arising from effective diaphragm area in the evaluation of performance of air operated valves. The performance assessment for the operability and structural integrity of air operated valves for the domestic nuclear power plant is in progress. One of the important parameters that determine the performance of the air operated valves is the effective diaphragm area of diaphragm type actuator. The effective diaphragm area is the actual area which the air pressure acting on the diaphragm. In general, the effective diaphragm area used for the performance evaluation of pneumatic actuator is provided by the manufacture or the actuator drawing. Flat type diaphragm was showed the difference between the measured value of EDA and the manufacture’s value, in the case of convoluted type diaphragm has showed that the measured value of EDA and manufacture’s value is almost the same. When evaluate a performance of a diaphragm actuator, accurate EDA is to be used because it is an important variable affecting the actuator performance. Particularly in the case of flat type diaphragm which EDA is changed in accordance with the stroke position, by using the EDA evaluation methodology developed in this study to minimize a possible error due to EDA when evaluating the performance of the air actuator.

  19. An investigation of the effects of pneumatic actuator design on slip control for heavy vehicles

    Science.gov (United States)

    Miller, Jonathan I.; Cebon, David

    2013-01-01

    Progress in reducing actuator delays in pneumatic brake systems is opening the door for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, little has been published on slip controllers for air-braked heavy vehicles, or the effects of slow pneumatic actuation on their design and performance. This paper introduces a sliding mode slip controller for air-braked heavy vehicles. The effects of pneumatic actuator delays and flow rates on stopping performance and air (energy) consumption are presented through vehicle simulations. Finally, the simulations are validated with experiments using a hardware-in-the-loop rig. It is shown that for each wheel, pneumatic valves with delays smaller than 3 ms and orifice diameters around 8 mm provide the best performance.

  20. Analysis of vibroprotection characteristics of pneumatic relaxation seat suspension with capability of vibration energy recuperation

    Directory of Open Access Journals (Sweden)

    Lyashenko Mikhail

    2017-01-01

    Full Text Available This paper proposes mechanism and control algorithm for pneumatic relaxation system of suspension with vibration energy recuperation applied to standard vehicle operator seat (“Sibeko” company. Mathematical model of the seat pneumatic relaxation suspension with two additional air volumes was created. Pneumatic motor – recuperator activated by means of air flow from the one additional volume to another is installed in air piping between additional volumes. Computational research was made in Matlab/Simulink. Amplitude-frequency characteristics of transmission coefficient for standard and proposed suspensions were plotted for preliminary evaluation of vibration protection properties of seat suspension. Performed comparative analysis of amplitude-frequency characteristics shows that noticeable improvement of vibration protection properties of pneumatic relaxation suspension system with vibration energy recuperation in comparison with standard system both in region of resonance disturbances and in above-resonance region. Main ways for further improvement of vibration protection properties of proposed system were marked out.