Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.579843
C. Liu-Hinz, B. Segal, B. Skulic, T. Pavlasek
Characterization of electromagnetic fields around portable radio-frequency sources within hospitals has been a topic of considerable recent interest within health-care settings because such fields can cause some medical devices to malfunction due to associated electromagnetic interference. Here, electromagnetic fields near portable radio-frequency sources were approximated by image techniques, using from 1 to 6 infinite conducting planes to approximate surrounding structures. The resulting predicted fields roughly accounted for deviations from free-space behaviour, as well as outdoor and indoor measurements.
{"title":"Electromagnetic fields near portable radio-frequency sources: estimates using image theory and measurements [hospital environment]","authors":"C. Liu-Hinz, B. Segal, B. Skulic, T. Pavlasek","doi":"10.1109/IEMBS.1995.579843","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579843","url":null,"abstract":"Characterization of electromagnetic fields around portable radio-frequency sources within hospitals has been a topic of considerable recent interest within health-care settings because such fields can cause some medical devices to malfunction due to associated electromagnetic interference. Here, electromagnetic fields near portable radio-frequency sources were approximated by image techniques, using from 1 to 6 infinite conducting planes to approximate surrounding structures. The resulting predicted fields roughly accounted for deviations from free-space behaviour, as well as outdoor and indoor measurements.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76641080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.574996
D. Huelsing, A. Pollard
The authors performed three-dimensional simulations of action potential propagation in a model of the peripheral conduction system connected to overlying ventricular myocardium. The authors' goal was to study the electrical interactions at the discrete subendocardial Purkinje-ventricular junctions (PVJ) and the nature of the load imposed on the Purkinje layer by the myocardium. The authors describe the construction of the model, which electrically connects an anisotropic sheet of myocardial cells to a layer of branching Purkinje cables through a transitional layer at discrete junctional sites. Simulations used the Luo and Rudy Phase I membrane equations for the myocardial and transitional components of the model and the Di Francesco and Noble membrane equations for the peripheral conduction system component.
{"title":"Loading effects of anisotropic ventricular muscle on the peripheral conduction system","authors":"D. Huelsing, A. Pollard","doi":"10.1109/IEMBS.1995.574996","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.574996","url":null,"abstract":"The authors performed three-dimensional simulations of action potential propagation in a model of the peripheral conduction system connected to overlying ventricular myocardium. The authors' goal was to study the electrical interactions at the discrete subendocardial Purkinje-ventricular junctions (PVJ) and the nature of the load imposed on the Purkinje layer by the myocardium. The authors describe the construction of the model, which electrically connects an anisotropic sheet of myocardial cells to a layer of branching Purkinje cables through a transitional layer at discrete junctional sites. Simulations used the Luo and Rudy Phase I membrane equations for the myocardial and transitional components of the model and the Di Francesco and Noble membrane equations for the peripheral conduction system component.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76650804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.579692
J. Dickey, M. Pierrynowski, D. Bednar, K. Ball
Three-dimensional (3D) dynamic segmental spinal kinematics were studied in low-back pain patients using infrared light emitting diodes mounted on bilateral percutaneous pedicle screws in one lower lumbar vertebra and the sacrum. Data were collected whilst four subjects performed a number of activities of daily living including bending in all planes. Three subjects showed limited motion (instrumented between LA or L5 and the sacrum), and one subject showed a range of motion approximately one-third of healthy young normal subjects (instrumented between L5 and the sacrum). Standing to flexion data for this patient exhibited motion suggestive of clinical instability.
{"title":"In vivo 3D rotational segmental spinal kinematics in low back pain patients","authors":"J. Dickey, M. Pierrynowski, D. Bednar, K. Ball","doi":"10.1109/IEMBS.1995.579692","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579692","url":null,"abstract":"Three-dimensional (3D) dynamic segmental spinal kinematics were studied in low-back pain patients using infrared light emitting diodes mounted on bilateral percutaneous pedicle screws in one lower lumbar vertebra and the sacrum. Data were collected whilst four subjects performed a number of activities of daily living including bending in all planes. Three subjects showed limited motion (instrumented between LA or L5 and the sacrum), and one subject showed a range of motion approximately one-third of healthy young normal subjects (instrumented between L5 and the sacrum). Standing to flexion data for this patient exhibited motion suggestive of clinical instability.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76792734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.575246
M. Moreau, D. Holdsworth, J. Dunmore-Buyze, A. Fenster
An in vitro radiographic technique has been developed to study the composition of arterial specimens, quantifying both the calcified and soft tissue components. In the authors' new method, planar radiographs of a phantom were obtained when the phantom was immersed in: (a) a saline bath using a 45-kV, spectrum with no added filtration; and, (b) an iodine bath using a 100-kV, spectrum with 12.5 mm Al added filtration. These radiographs were then digitized and converted into bone-equivalent and Lucite images using calibration data obtained from images of Lucite and bone-equivalent step wedges. Thickness measurements from these images yielded average accuracies of /spl plusmn/300 /spl mu/m for the bone-equivalent image, and /spl plusmn/80 /spl mu/m for the Lucite image. The precision (one standard deviation) of the thickness measurements was 200 /spl mu/m and /spl plusmn/150 /spl mu/m for the bone-equivalent and the Lucite images respectively. Although the accuracy and precision of bone-equivalent thickness measurements were not as good as those obtained with dual-energy X-ray imaging, the accuracy and precision of the Lucite thickness measurements are shown to be much better. The high accuracy and precision of the Lucite thickness measurements make this technique a very good complement to dual-energy radiography (with its high accuracy and precision of bone-equivalent thickness measurement) to study the physical properties of excised arterial specimens.
{"title":"X-ray imaging technique for in vitro tissue composition measurements using saline/iodine displacement","authors":"M. Moreau, D. Holdsworth, J. Dunmore-Buyze, A. Fenster","doi":"10.1109/IEMBS.1995.575246","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575246","url":null,"abstract":"An in vitro radiographic technique has been developed to study the composition of arterial specimens, quantifying both the calcified and soft tissue components. In the authors' new method, planar radiographs of a phantom were obtained when the phantom was immersed in: (a) a saline bath using a 45-kV, spectrum with no added filtration; and, (b) an iodine bath using a 100-kV, spectrum with 12.5 mm Al added filtration. These radiographs were then digitized and converted into bone-equivalent and Lucite images using calibration data obtained from images of Lucite and bone-equivalent step wedges. Thickness measurements from these images yielded average accuracies of /spl plusmn/300 /spl mu/m for the bone-equivalent image, and /spl plusmn/80 /spl mu/m for the Lucite image. The precision (one standard deviation) of the thickness measurements was 200 /spl mu/m and /spl plusmn/150 /spl mu/m for the bone-equivalent and the Lucite images respectively. Although the accuracy and precision of bone-equivalent thickness measurements were not as good as those obtained with dual-energy X-ray imaging, the accuracy and precision of the Lucite thickness measurements are shown to be much better. The high accuracy and precision of the Lucite thickness measurements make this technique a very good complement to dual-energy radiography (with its high accuracy and precision of bone-equivalent thickness measurement) to study the physical properties of excised arterial specimens.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76822182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.579788
R. Katz, M. Lawee, A. Newman, J. Woodrow Weiss
Nonlinear/chaotic algorithms are used for automatic detection and clinical monitoring of obstructive sleep apnea (OSA). We cite an example taken from a group of adults where similar results are obtained. The algorithms are applied to clinical time series of airflow (thermistry), chest effort (impedance) and electrocardiogram (ECG) traces obtained from sleep apnea records (Edentrace Systems). These algorithms may be applied to a variety of other data sets (i.e. oxygen saturation, heart rate). The algorithms can pinpoint the onset of a disabling disorder (i.e apnea) and mark the duration of the event. They are robust when applied to multiple data sets in which obstructive apneas are known to occur.
{"title":"For automatic detection and monitoring of obstructive sleep apnea","authors":"R. Katz, M. Lawee, A. Newman, J. Woodrow Weiss","doi":"10.1109/IEMBS.1995.579788","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579788","url":null,"abstract":"Nonlinear/chaotic algorithms are used for automatic detection and clinical monitoring of obstructive sleep apnea (OSA). We cite an example taken from a group of adults where similar results are obtained. The algorithms are applied to clinical time series of airflow (thermistry), chest effort (impedance) and electrocardiogram (ECG) traces obtained from sleep apnea records (Edentrace Systems). These algorithms may be applied to a variety of other data sets (i.e. oxygen saturation, heart rate). The algorithms can pinpoint the onset of a disabling disorder (i.e apnea) and mark the duration of the event. They are robust when applied to multiple data sets in which obstructive apneas are known to occur.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77077667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.575314
K. Nakajima, T. Tamura, L. Lu, H. Miike, S. Kasaoka, K. Nakashima, T. Maekawa, T. Togawa
Recently, early ambulation has been introduced to treat patients after acute myocardial infarction (AMI). In order to perform early rehabilitation, physical activity should be evaluated during not only exercise, but also bed rest. In this preliminary study, the body movement, as an index of physical activity, of AMI patients in the authors' coronary care unit was determined. Body movement was estimated using a bed temperature evaluation function, which correlated to increased heart rate. The total number of body movements increased day by day. This method could be used as an index of physical activity of AMI patients during bed rest to guide early rehabilitation.
{"title":"Evaluation of bed rest using a bed temperature monitor after acute myocardial infarction","authors":"K. Nakajima, T. Tamura, L. Lu, H. Miike, S. Kasaoka, K. Nakashima, T. Maekawa, T. Togawa","doi":"10.1109/IEMBS.1995.575314","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575314","url":null,"abstract":"Recently, early ambulation has been introduced to treat patients after acute myocardial infarction (AMI). In order to perform early rehabilitation, physical activity should be evaluated during not only exercise, but also bed rest. In this preliminary study, the body movement, as an index of physical activity, of AMI patients in the authors' coronary care unit was determined. Body movement was estimated using a bed temperature evaluation function, which correlated to increased heart rate. The total number of body movements increased day by day. This method could be used as an index of physical activity of AMI patients during bed rest to guide early rehabilitation.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82163990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.579640
B. Neisius, P. Dautzenberg, R. Trapp, G. Buess
A concept of a telemanipulator for laparoscopic surgery is presented. It enables endoscopic handling of surgical effecters and cameras inside the abdominal cavity with six degrees of freedom of motion through a trocar tube 12 mm in diameter. The kinematical structure consists of fourteen axes articulated by six electrical servo drives.
{"title":"Robotic telemanipulator for laparoscopy","authors":"B. Neisius, P. Dautzenberg, R. Trapp, G. Buess","doi":"10.1109/IEMBS.1995.579640","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579640","url":null,"abstract":"A concept of a telemanipulator for laparoscopic surgery is presented. It enables endoscopic handling of surgical effecters and cameras inside the abdominal cavity with six degrees of freedom of motion through a trocar tube 12 mm in diameter. The kinematical structure consists of fourteen axes articulated by six electrical servo drives.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81326397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.575103
A.N. Mears, L. Holley
This study examines whether uniform and nonuniform electric field topologies as generated by different defibrillation electrode configurations influence defibrillation threshold energies (DFT) for monophasic (MP) and biphasic (BP) shock waveforms. Recent theoretical studies have suggested that the ability of BP to change transmembrane potential may be enhanced under non-uniform field conditions. This may also influence the efficacy of defibrillation of BP waveforms, Also, contradictory experimental results in the comparison of BP versus MP efficacy have been reported. These may be due to different experimental setups resulting in different shock electric field non-uniformity. To test the hypothesis that electric field non-uniformity influences relative defibrillation efficacy for MP and BP waveforms we determined DFT delivered to the heart under two electrode configurations. A catheter electrode was used to create a non-uniform field and a pair of parallel plates created a uniform field. The results show that BP is more efficacious than MP under both uniform and non-uniform field conditions (p<0.05) and that the efficacy off BP is enhanced under non-uniform fields (p<0.005) whilst there is no observed difference between uniform and non-uniform fields for MP waveforms.
{"title":"The effect of uniform and non-uniform electric fields on defibrillation thresholds for monophasic and biphasic waveforms","authors":"A.N. Mears, L. Holley","doi":"10.1109/IEMBS.1995.575103","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575103","url":null,"abstract":"This study examines whether uniform and nonuniform electric field topologies as generated by different defibrillation electrode configurations influence defibrillation threshold energies (DFT) for monophasic (MP) and biphasic (BP) shock waveforms. Recent theoretical studies have suggested that the ability of BP to change transmembrane potential may be enhanced under non-uniform field conditions. This may also influence the efficacy of defibrillation of BP waveforms, Also, contradictory experimental results in the comparison of BP versus MP efficacy have been reported. These may be due to different experimental setups resulting in different shock electric field non-uniformity. To test the hypothesis that electric field non-uniformity influences relative defibrillation efficacy for MP and BP waveforms we determined DFT delivered to the heart under two electrode configurations. A catheter electrode was used to create a non-uniform field and a pair of parallel plates created a uniform field. The results show that BP is more efficacious than MP under both uniform and non-uniform field conditions (p<0.05) and that the efficacy off BP is enhanced under non-uniform fields (p<0.005) whilst there is no observed difference between uniform and non-uniform fields for MP waveforms.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81448455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.575329
T. Gansler, M. Hansson, G. Salomonsson
The latency and amplitude of the midlatency auditive evoked potential's (AEP) Nb-trough has been found to indicate the depth of anaesthesis. The aim of this paper is to present a system that reliably estimates these parameters without a long time delay. The result shows that it is possible to estimate and track changes in latency and amplitude of the Nb-trough with a delay below 1 minute at a stimulus rate of 8.4 Hz.
中潜伏期听觉诱发电位(AEP) nb -波谷的潜伏期和振幅表明麻醉的深度。本文的目的是提出一个系统，可靠地估计这些参数，没有很长的时间延迟。结果表明，在8.4 Hz的刺激速率下，可以估计和跟踪延迟小于1分钟的nb -波谷潜伏期和振幅的变化。
{"title":"A system for tracking the depth of anaesthesia","authors":"T. Gansler, M. Hansson, G. Salomonsson","doi":"10.1109/IEMBS.1995.575329","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.575329","url":null,"abstract":"The latency and amplitude of the midlatency auditive evoked potential's (AEP) Nb-trough has been found to indicate the depth of anaesthesis. The aim of this paper is to present a system that reliably estimates these parameters without a long time delay. The result shows that it is possible to estimate and track changes in latency and amplitude of the Nb-trough with a delay below 1 minute at a stimulus rate of 8.4 Hz.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82336467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1995-09-20DOI: 10.1109/IEMBS.1995.579832
A. Dittmar, F. Arnaud, G. Delhomme, P. Girard, W. Newman, C. Martelet
A non invasive microsensor was designed for the study of the time course of both water content and microcirculation of the skin related to physiological, pharmacological, and cosmetics experiments. This microsensor uses the principle of thermal diffusion in skin layers.
{"title":"Non invasive characterization of skin using micro thermal diffusion sensor","authors":"A. Dittmar, F. Arnaud, G. Delhomme, P. Girard, W. Newman, C. Martelet","doi":"10.1109/IEMBS.1995.579832","DOIUrl":"https://doi.org/10.1109/IEMBS.1995.579832","url":null,"abstract":"A non invasive microsensor was designed for the study of the time course of both water content and microcirculation of the skin related to physiological, pharmacological, and cosmetics experiments. This microsensor uses the principle of thermal diffusion in skin layers.","PeriodicalId":20509,"journal":{"name":"Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1995-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78909926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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