Pub Date : 1988-11-01DOI: 10.1109/IEMBS.1988.94558
H.S. Choi, R. Dilley, Y. Kim, S. M. Schwartz
One of the major sources of the coefficient of variation in quantitative digital image analysis systems is the distribution error. It is caused by uneven optical density distribution within the measuring area. In digital image analysis systems, the measuring area is an individual pixel. The distribution error would be eliminated if we could measure the average optical density within the measuring area. However, most cameras used with light microscopes measure the average transmittance of a pixel. The image analysis system then converts the measured transmittance into an optical density. If the optical density distribution within a pixel is not uniform, the average optical density converted from the measured transmittance is different from the true optical density of the pixel. The authors call this conversional distribution error (CDE). They have analyzed and characterized this error, and developed an algorithm to minimize CDE by estimating the optical density distribution within a pixel.<>
{"title":"Distribution error in quantitative digital image analysis systems and its correction algorithm","authors":"H.S. Choi, R. Dilley, Y. Kim, S. M. Schwartz","doi":"10.1109/IEMBS.1988.94558","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94558","url":null,"abstract":"One of the major sources of the coefficient of variation in quantitative digital image analysis systems is the distribution error. It is caused by uneven optical density distribution within the measuring area. In digital image analysis systems, the measuring area is an individual pixel. The distribution error would be eliminated if we could measure the average optical density within the measuring area. However, most cameras used with light microscopes measure the average transmittance of a pixel. The image analysis system then converts the measured transmittance into an optical density. If the optical density distribution within a pixel is not uniform, the average optical density converted from the measured transmittance is different from the true optical density of the pixel. The authors call this conversional distribution error (CDE). They have analyzed and characterized this error, and developed an algorithm to minimize CDE by estimating the optical density distribution within a pixel.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122525420","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94509
Y. Yamamoto, Y. Kawakami, Y. Nakamura, K. Mokushi, Y. Mutoh, M. Miyashita
The authors detect the anerobic threshold (AT) only from heart rate (HR) recording. Ten subjects performed 13-min cycle exercise on an electrically braked ergometer. The work rate (WR) varied between 40-100 by a pseudorandom binary sequence (dt=1 s, 8 bits, 3 cycles), while HR (beats/min) was calculated every second from R-R intervals. Frequency analysis revealed that the transferred gains from WR to HR at the frequencies of 0.1, 0.2, and 0.3 Hz were less attenuated for all subjects comparing to those of the other frequencies. Therefore, each subject performed incremental exercise (mean Delta =0.33 W/s) with the compounded sinusoidal fluctuation. From this study, it is concluded that AT can be determined only from HR recording. As HR is one of the easiest parameters to measure, especially during exercise, evaluation of AT would therefore be easier by this method.<>
{"title":"A new method for detecting anaerobic threshold from heart rate recording","authors":"Y. Yamamoto, Y. Kawakami, Y. Nakamura, K. Mokushi, Y. Mutoh, M. Miyashita","doi":"10.1109/IEMBS.1988.94509","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94509","url":null,"abstract":"The authors detect the anerobic threshold (AT) only from heart rate (HR) recording. Ten subjects performed 13-min cycle exercise on an electrically braked ergometer. The work rate (WR) varied between 40-100 by a pseudorandom binary sequence (dt=1 s, 8 bits, 3 cycles), while HR (beats/min) was calculated every second from R-R intervals. Frequency analysis revealed that the transferred gains from WR to HR at the frequencies of 0.1, 0.2, and 0.3 Hz were less attenuated for all subjects comparing to those of the other frequencies. Therefore, each subject performed incremental exercise (mean Delta =0.33 W/s) with the compounded sinusoidal fluctuation. From this study, it is concluded that AT can be determined only from HR recording. As HR is one of the easiest parameters to measure, especially during exercise, evaluation of AT would therefore be easier by this method.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133207175","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94551
W. Higgins, E. Ritman
The authors describe a region-sharpening technique that expands earlier work. The technique has two steps: (1) definition of a set of sector templates; and (2) application of the templates to an image. An arbitrary number of arbitrarily sized sectors can be defined. Thus, varying levels of region sharpening can be achieved. When the technique is applied to cardiac X-ray CT (computed tomography) images containing a contrast-enhanced left-ventricular chamber the myocardium and chamber become more sharply defined and noise is reduced. Since the technique is not context-dependent, it is applicable to other imaging modalities.<>
{"title":"A region sharpening technique for biomedical images","authors":"W. Higgins, E. Ritman","doi":"10.1109/IEMBS.1988.94551","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94551","url":null,"abstract":"The authors describe a region-sharpening technique that expands earlier work. The technique has two steps: (1) definition of a set of sector templates; and (2) application of the templates to an image. An arbitrary number of arbitrarily sized sectors can be defined. Thus, varying levels of region sharpening can be achieved. When the technique is applied to cardiac X-ray CT (computed tomography) images containing a contrast-enhanced left-ventricular chamber the myocardium and chamber become more sharply defined and noise is reduced. Since the technique is not context-dependent, it is applicable to other imaging modalities.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117069393","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94467
L. Eisenman, N. Thakor
A 3-D model is reconstructed from an isolated dog heart and discretized into 1473 elements. By incorporating the details of activation of nearest neighbors, velocity of propagation, and refractoriness of previously excited tissue, electrical propagation in normal heart is simulated. Excitation by six to ten extrastimuli results in a self-sustaining random activity considered equivalent of ventricular fibrillation (VF). This model reproduces some known experimental observations and predicts induction of VF by recurrent excitation and dispersion of refractory states in cardiac elements.<>
{"title":"Simulation of ventricular fibrillation in a three-dimensional model of heart","authors":"L. Eisenman, N. Thakor","doi":"10.1109/IEMBS.1988.94467","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94467","url":null,"abstract":"A 3-D model is reconstructed from an isolated dog heart and discretized into 1473 elements. By incorporating the details of activation of nearest neighbors, velocity of propagation, and refractoriness of previously excited tissue, electrical propagation in normal heart is simulated. Excitation by six to ten extrastimuli results in a self-sustaining random activity considered equivalent of ventricular fibrillation (VF). This model reproduces some known experimental observations and predicts induction of VF by recurrent excitation and dispersion of refractory states in cardiac elements.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130847767","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.95316
H. Sasabe, T. Furuno, A. Sato, K. Ulmer
A two-dimensional protein crystal that preserves biological function is necessary for the realization of bioelectronic devices. The authors have fabricated a close-packed purple membrane (PM) monolayer by the Langmuir-Blodgett technique and studied the proton transfer through the membrane under the photoexcitation. The PM monolayer is transferred to an indium-tin-oxide or Al-deposited glass substrated and/or a Si wafer by a horizontal transfer technique. The morphology of monolayer films was directly investigated by SEM. From the static and dynamic measurement of photovoltaic effect in the PM multilayer, it was confirmed that the photochemical cycle of the bacteriorhodopsin (membrane protein of PM) was preserved. The two-dimensional packing of globular protein ferritin was also investigated. Depending on the surface pressure applied, the packing changes in a chainlike aggregate or in a fairly good lattice (small patch).<>
{"title":"2-dimensional protein crystals for bioelectronics","authors":"H. Sasabe, T. Furuno, A. Sato, K. Ulmer","doi":"10.1109/IEMBS.1988.95316","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95316","url":null,"abstract":"A two-dimensional protein crystal that preserves biological function is necessary for the realization of bioelectronic devices. The authors have fabricated a close-packed purple membrane (PM) monolayer by the Langmuir-Blodgett technique and studied the proton transfer through the membrane under the photoexcitation. The PM monolayer is transferred to an indium-tin-oxide or Al-deposited glass substrated and/or a Si wafer by a horizontal transfer technique. The morphology of monolayer films was directly investigated by SEM. From the static and dynamic measurement of photovoltaic effect in the PM multilayer, it was confirmed that the photochemical cycle of the bacteriorhodopsin (membrane protein of PM) was preserved. The two-dimensional packing of globular protein ferritin was also investigated. Depending on the surface pressure applied, the packing changes in a chainlike aggregate or in a fairly good lattice (small patch).<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128429341","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94446
T. Arai, M. Nakagawa, M. Kikuchi, K. Mizuno, K. Arakawa, T. Shibuya, K. Satomura, A. Miyamoto, Y. Okamato, K. Isojima, A. Kurita, H. Nakamura, A. Utsumi, K. Takeuchi
A study was made of a laser angioplasty system using a CO laser, 5 mu m in wavelength. To achieve therapeutic irradiation in a water solution, the authors developed a contact CO laser irradiation method which uses an optical fiber to carry the laser beam to the lesion. The authors have also developed a thin coronary angioscope catheter for diagnosis and targeting of this therapy.<>
{"title":"Laser coronary angioplasty using carbon monoxide lasers","authors":"T. Arai, M. Nakagawa, M. Kikuchi, K. Mizuno, K. Arakawa, T. Shibuya, K. Satomura, A. Miyamoto, Y. Okamato, K. Isojima, A. Kurita, H. Nakamura, A. Utsumi, K. Takeuchi","doi":"10.1109/IEMBS.1988.94446","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94446","url":null,"abstract":"A study was made of a laser angioplasty system using a CO laser, 5 mu m in wavelength. To achieve therapeutic irradiation in a water solution, the authors developed a contact CO laser irradiation method which uses an optical fiber to carry the laser beam to the lesion. The authors have also developed a thin coronary angioscope catheter for diagnosis and targeting of this therapy.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128726316","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.95379
J. Chen, J. Vandewalle, W. Sansen, E. Van Cutsem, G. Vantrappen, J. Janssens
The authors show that the propagation of the gastric activities in the stomach can be detected from abdominally recorded EGGs (electrogastrograms). The conventional measurement method is not adequate for detecting the propagation. The stomach must be carefully localized before the measurement. The electrodes should be attached on the abdomen along the longitudinal axis of the stomach. Phase shifts have been observed from all of the volunteers and patients with the position of the stomach localized by X-ray. It is easier to detect phase shifts in fasting than in postprandial situations. The reason could be that there exist more contractions in the stomach in the postprandial situation. These contraction-related gastric activities do not propagate as regularly as the slow waves, which makes the cutaneous EGGs more complicated.<>
{"title":"Observations of phase shifts from cutaneous electrogastrography","authors":"J. Chen, J. Vandewalle, W. Sansen, E. Van Cutsem, G. Vantrappen, J. Janssens","doi":"10.1109/IEMBS.1988.95379","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.95379","url":null,"abstract":"The authors show that the propagation of the gastric activities in the stomach can be detected from abdominally recorded EGGs (electrogastrograms). The conventional measurement method is not adequate for detecting the propagation. The stomach must be carefully localized before the measurement. The electrodes should be attached on the abdomen along the longitudinal axis of the stomach. Phase shifts have been observed from all of the volunteers and patients with the position of the stomach localized by X-ray. It is easier to detect phase shifts in fasting than in postprandial situations. The reason could be that there exist more contractions in the stomach in the postprandial situation. These contraction-related gastric activities do not propagate as regularly as the slow waves, which makes the cutaneous EGGs more complicated.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116044682","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94788
F. Catani, S. Giannini, F. Bombardi, M. Marcacci, F. Ceccarelli
The purpose of this study was to focus on gait pattern abnormality in hip-joint arthrodesis patients and correlate them with a normal population similar in age and sex. The importance of a long-term follow-up (in this case 20 years) is to assess the presence of secondary degenerative arthrosis in joints which are biomechanically and anatomically correlated to the fused hip. It is found that basic gait abnormalities are due to kinematic and kinetic alterations that are the result of compensatory mechanisms used to overcome the lack of hip flexion-extension, ab-adduction and external-internal rotation. The hip-joint arthrodesis patient gait is characterized by an increased sagittal and transverse rotation of the pelvis, increased motion of the sound hip, and a decreased omolateral knee extension during the first part of the stance phase.<>
{"title":"Walking patterns in 20 years follow-up hip joint arthrodesis patients","authors":"F. Catani, S. Giannini, F. Bombardi, M. Marcacci, F. Ceccarelli","doi":"10.1109/IEMBS.1988.94788","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94788","url":null,"abstract":"The purpose of this study was to focus on gait pattern abnormality in hip-joint arthrodesis patients and correlate them with a normal population similar in age and sex. The importance of a long-term follow-up (in this case 20 years) is to assess the presence of secondary degenerative arthrosis in joints which are biomechanically and anatomically correlated to the fused hip. It is found that basic gait abnormalities are due to kinematic and kinetic alterations that are the result of compensatory mechanisms used to overcome the lack of hip flexion-extension, ab-adduction and external-internal rotation. The hip-joint arthrodesis patient gait is characterized by an increased sagittal and transverse rotation of the pelvis, increased motion of the sound hip, and a decreased omolateral knee extension during the first part of the stance phase.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116809866","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94899
A. Patwardhan, S. Li, T. Gavin, K. Meade, M. Lorenz
The effect of injury to the thoracolumbar spinal segment and the influence of orthotic support on the stability of the spine was studied using a finite-element model of the spine. The stability of an injured spine with and without orthotic support was evaluated in terms of the progression of translational and angular deformity at the injured segment when the spine was subjected to gravitational loads and flexion moment in the upright posture. Results indicate that a hyperextension orthosis improves the stability of the model spine whose ability to withstand gravitational and flexion loads was severely compromised due to injury at T12-L2 segment.<>
{"title":"Effect of injury and orthotic support on the stability of the spine","authors":"A. Patwardhan, S. Li, T. Gavin, K. Meade, M. Lorenz","doi":"10.1109/IEMBS.1988.94899","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94899","url":null,"abstract":"The effect of injury to the thoracolumbar spinal segment and the influence of orthotic support on the stability of the spine was studied using a finite-element model of the spine. The stability of an injured spine with and without orthotic support was evaluated in terms of the progression of translational and angular deformity at the injured segment when the spine was subjected to gravitational loads and flexion moment in the upright posture. Results indicate that a hyperextension orthosis improves the stability of the model spine whose ability to withstand gravitational and flexion loads was severely compromised due to injury at T12-L2 segment.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114682464","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 : 1988-11-01DOI: 10.1109/IEMBS.1988.94388
M. Fuller, R. Freedman, S. Lyver, T. B. McLaughlin
Signal averaged electrocardiograms (SAEs) of subjects with and without late potentials were compared. using windows of 50- and 100-m widths, short-time Fourier analysis was performed on each electrocardiogram. Frequency ratios of the energy between 0 and 40 Hz and 40 and 120 Hz were computed for each time shift of the window for all SAEs. Those with late potentials (LPs) could be distinguished from those without LPs on the basis of the energy ratio computed using the 100-ms window.<>
{"title":"Short-time Fourier analysis of signal averaged electrocardiograms","authors":"M. Fuller, R. Freedman, S. Lyver, T. B. McLaughlin","doi":"10.1109/IEMBS.1988.94388","DOIUrl":"https://doi.org/10.1109/IEMBS.1988.94388","url":null,"abstract":"Signal averaged electrocardiograms (SAEs) of subjects with and without late potentials were compared. using windows of 50- and 100-m widths, short-time Fourier analysis was performed on each electrocardiogram. Frequency ratios of the energy between 0 and 40 Hz and 40 and 120 Hz were computed for each time shift of the window for all SAEs. Those with late potentials (LPs) could be distinguished from those without LPs on the basis of the energy ratio computed using the 100-ms window.<<ETX>>","PeriodicalId":227170,"journal":{"name":"Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125434148","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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