Pub Date : 1995-04-07DOI: 10.1109/SBEC.1995.514506
J.R. Tamarapalli, R. Meyer, J. Lemons
Surgical endoscopy is defined as the visual observation within body cavities or regional soft tissues with the help of a controlled optical system. Surgical skills for endoscopy or arthroscopy (looking inside joints) require considerable specialized training. Endoscopy images are projected from the surgical field through an optical scope and television camera to an indirectly located TV monitor. The surgeon operates with unconventional instruments while watching the endoscopic image on a TV monitor. A multipurpose training apparatus was developed to give hands-on training to surgeons intending to use arthroscopic and endoscopic procedures. Initially, a knee model apparatus was developed for training arthroscopic surgeons and subsequently, this apparatus was modified to accommodate the training of endoscopic surgeons. Practice on this training model can: help prevent injury to the patient because of suboptimal skills; be adopted for other surgical specialties; minimize damage to surgical instruments; and save training costs with minimal recurrent expenditures.
{"title":"A multipurpose endoscopy training apparatus","authors":"J.R. Tamarapalli, R. Meyer, J. Lemons","doi":"10.1109/SBEC.1995.514506","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514506","url":null,"abstract":"Surgical endoscopy is defined as the visual observation within body cavities or regional soft tissues with the help of a controlled optical system. Surgical skills for endoscopy or arthroscopy (looking inside joints) require considerable specialized training. Endoscopy images are projected from the surgical field through an optical scope and television camera to an indirectly located TV monitor. The surgeon operates with unconventional instruments while watching the endoscopic image on a TV monitor. A multipurpose training apparatus was developed to give hands-on training to surgeons intending to use arthroscopic and endoscopic procedures. Initially, a knee model apparatus was developed for training arthroscopic surgeons and subsequently, this apparatus was modified to accommodate the training of endoscopic surgeons. Practice on this training model can: help prevent injury to the patient because of suboptimal skills; be adopted for other surgical specialties; minimize damage to surgical instruments; and save training costs with minimal recurrent expenditures.","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122059991","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 : 1995-04-07DOI: 10.1109/SBEC.1995.514499
J. Lankford, C. Blanchard, C. M. Agrawal
The effect of varying the initial surface roughness of ultrahigh molecular weight polyethylene (UHMWPE) tested in reciprocating wear against CoCr pins in bovine serum is investigated. It is found that wear occurs in two distinct stages that appear and disappear cyclically. The low wear phase corresponds to the development of surface deformation features that degenerate into a high amplitude wavelike topography. The features wear by fibrillar pullout and microfracture, producing submicrometer particulate debris.
{"title":"Wear mechanisms and particle generation in ultrahigh molecular weight polyethylene","authors":"J. Lankford, C. Blanchard, C. M. Agrawal","doi":"10.1109/SBEC.1995.514499","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514499","url":null,"abstract":"The effect of varying the initial surface roughness of ultrahigh molecular weight polyethylene (UHMWPE) tested in reciprocating wear against CoCr pins in bovine serum is investigated. It is found that wear occurs in two distinct stages that appear and disappear cyclically. The low wear phase corresponds to the development of surface deformation features that degenerate into a high amplitude wavelike topography. The features wear by fibrillar pullout and microfracture, producing submicrometer particulate debris.","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125440929","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 : 1995-04-07DOI: 10.1109/SBEC.1995.514433
V. Bucalo, K. Bundy
Recent clinical retrieval studies have shown that extensive attack often occurs in modular total hip replacements (THR's). Proposed causes for the degradation of these implants include galvanic, crevice, and fretting corrosion, as well as combinations of these effects. The research described here is part of an ongoing study to determine the mechanism or mechanisms behind these high rates of attack. DC electrochemical techniques have been employed to conduct short, term studies related to device corrosion and fretting. The results suggest that fretting accelerated crevice corrosion is sufficient but not necessary for severe attack of modular THR's. Crevice conditions alone may cause the attack, if the pH and p/sub O2/ levels decline sufficiently far.
{"title":"Deaeration, pH shift, and surface disruption effects on the corrosion of modular THR alloys","authors":"V. Bucalo, K. Bundy","doi":"10.1109/SBEC.1995.514433","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514433","url":null,"abstract":"Recent clinical retrieval studies have shown that extensive attack often occurs in modular total hip replacements (THR's). Proposed causes for the degradation of these implants include galvanic, crevice, and fretting corrosion, as well as combinations of these effects. The research described here is part of an ongoing study to determine the mechanism or mechanisms behind these high rates of attack. DC electrochemical techniques have been employed to conduct short, term studies related to device corrosion and fretting. The results suggest that fretting accelerated crevice corrosion is sufficient but not necessary for severe attack of modular THR's. Crevice conditions alone may cause the attack, if the pH and p/sub O2/ levels decline sufficiently far.","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129575062","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 : 1995-04-07DOI: 10.1109/SBEC.1995.514472
K. Cheng
Quantum biomechanical models, based on three dimensional (3-D) steady state Schrodinger equations in a single particle system and in a time independent field, are developed to describe the movement of a particle (an ion or an ion group) in an approximately cuboidal tube-like channel and an approximately cylindrical tube-like channel and to describe a single channel current. The particle is assumed to travel in a longitudinal direction and to wave in transversal directions in the channels. Concepts of the effective constant height (V/sub 2/) and length (L/sub x/) of the potential energy barrier in the longitudinal direction, the effective height (L/sub y/) and width (L/sub z/) of the cuboidal channel and the effective radius (a) of the cylindrical channel in the transversal directions, are used in the models to obtain analytical solutions in mathematics. The models elucidate that: (1) A particle is free and trapped in an infinite deep potential energy well in the transversal directions while it penetrates the channels. The particle's transversal wave functions obey sinusoidal functions for the cuboidal channel and obey Bessel functions of the first kind with zero order for the cylindrical channel. The particle's transversal energies are discrete in the two groups of channel. The highest probability, a particle can be found in a cross section within the channels, is on or close to the longitudinal axis. (2) V/sub 2/ is mostly determined by the repulsion energy, which is produced by the electric interaction between a particle and a channel, V/sub 2//spl prop/1/L/sub y//sup /spl alpha// and V/sub 2//spl prop/1/L/sub z//sup /spl alpha// for the cuboidal channel and V/sub 2//spl prop/1/a/sup /spl alpha// for the cylindrical channel, where, /spl alpha/ is a coefficient of the interaction and /spl alpha/=1, 2, 3, 4, 5 or 6 depending on the category of the interaction. As an estimation, a single mini-K/sup +/ channel current may decrease 10,000 times from its open state to its close state, while the effective constant height of potential energy barrier (V/sub 2/) increases only 125% (from 0.2 eV to 0.45 eV) and the effective radius (a) decreases only 22% (/spl alpha/=4).
{"title":"Development of 3-D quantum biomechanical models of a single particle movement through a channel and a single channel current","authors":"K. Cheng","doi":"10.1109/SBEC.1995.514472","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514472","url":null,"abstract":"Quantum biomechanical models, based on three dimensional (3-D) steady state Schrodinger equations in a single particle system and in a time independent field, are developed to describe the movement of a particle (an ion or an ion group) in an approximately cuboidal tube-like channel and an approximately cylindrical tube-like channel and to describe a single channel current. The particle is assumed to travel in a longitudinal direction and to wave in transversal directions in the channels. Concepts of the effective constant height (V/sub 2/) and length (L/sub x/) of the potential energy barrier in the longitudinal direction, the effective height (L/sub y/) and width (L/sub z/) of the cuboidal channel and the effective radius (a) of the cylindrical channel in the transversal directions, are used in the models to obtain analytical solutions in mathematics. The models elucidate that: (1) A particle is free and trapped in an infinite deep potential energy well in the transversal directions while it penetrates the channels. The particle's transversal wave functions obey sinusoidal functions for the cuboidal channel and obey Bessel functions of the first kind with zero order for the cylindrical channel. The particle's transversal energies are discrete in the two groups of channel. The highest probability, a particle can be found in a cross section within the channels, is on or close to the longitudinal axis. (2) V/sub 2/ is mostly determined by the repulsion energy, which is produced by the electric interaction between a particle and a channel, V/sub 2//spl prop/1/L/sub y//sup /spl alpha// and V/sub 2//spl prop/1/L/sub z//sup /spl alpha// for the cuboidal channel and V/sub 2//spl prop/1/a/sup /spl alpha// for the cylindrical channel, where, /spl alpha/ is a coefficient of the interaction and /spl alpha/=1, 2, 3, 4, 5 or 6 depending on the category of the interaction. As an estimation, a single mini-K/sup +/ channel current may decrease 10,000 times from its open state to its close state, while the effective constant height of potential energy barrier (V/sub 2/) increases only 125% (from 0.2 eV to 0.45 eV) and the effective radius (a) decreases only 22% (/spl alpha/=4).","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125790909","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 : 1995-04-07DOI: 10.1109/SBEC.1995.514420
L. S. Rogers, C. Bowling
Digital angiography is a medical procedure that is used to visualize blood flow. A radioisotope is injected through a catheter that has been maneuvered into the area to be visualized. A sequence of X-ray images is then captured. Digital subtraction is performed between X-ray images captured before and after the dye injection in order to visualize blood flow, without obscuring anatomical structures. Many hemodynamic parameters can now be determined, including blood how velocity. What is lacking in this procedure, however, is a measure by which the method for velocity determination can be verified. Here, the authors present the first step towards verification of automatic flow velocity calculation. They offer an objective comparison of four methods for automatic fluid velocity calculation in which the actual flow velocity is known. They give a concise description of the theory behind and implementation of each method. Finally, the authors discuss the results of applying the four techniques to their experimental data.
{"title":"Automatic fluid velocity detection methods for digital angiography","authors":"L. S. Rogers, C. Bowling","doi":"10.1109/SBEC.1995.514420","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514420","url":null,"abstract":"Digital angiography is a medical procedure that is used to visualize blood flow. A radioisotope is injected through a catheter that has been maneuvered into the area to be visualized. A sequence of X-ray images is then captured. Digital subtraction is performed between X-ray images captured before and after the dye injection in order to visualize blood flow, without obscuring anatomical structures. Many hemodynamic parameters can now be determined, including blood how velocity. What is lacking in this procedure, however, is a measure by which the method for velocity determination can be verified. Here, the authors present the first step towards verification of automatic flow velocity calculation. They offer an objective comparison of four methods for automatic fluid velocity calculation in which the actual flow velocity is known. They give a concise description of the theory behind and implementation of each method. Finally, the authors discuss the results of applying the four techniques to their experimental data.","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"307 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121683656","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 : 1995-04-07DOI: 10.1109/SBEC.1995.514493
A. Pearsall
Isolated injuries to the posterior cruciate ligament (PCL) are only now being recognized for their severity and their potential repercussions upon function of the knee. As more long term follow up studies of patients with untreated isolated PCL injuries are reported, the sequelae of this injury are being described. The previously held belief that isolated PCL injuries are relatively innocuous and require only conservative treatment is now being questioned. The posterior cruciate ligament is a complex anatomical structure that does not appear to demonstrate the isometric characteristics of its counterpart in the knee, the anterior cruciate ligament. Rather, it consists predominately of a nonisometric anterior bundle that resists posterior displacement of the tibia throughout the majority of knee range of motion. Changes in fiber-bundle length during knee motion appear to be most affected by changes in the femoral attachment site of the PCL graft. When reconstruction of the PCL is being considered, the anterior femoral location should be selected, the graft should be tensioned at ninety degrees of knee flexion, and a anterior tibial force should be applied prior to final graft fixation.
{"title":"Reconstruction of the posterior cruciate ligament of the knee: anatomic, isometric, and tensioning considerations","authors":"A. Pearsall","doi":"10.1109/SBEC.1995.514493","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514493","url":null,"abstract":"Isolated injuries to the posterior cruciate ligament (PCL) are only now being recognized for their severity and their potential repercussions upon function of the knee. As more long term follow up studies of patients with untreated isolated PCL injuries are reported, the sequelae of this injury are being described. The previously held belief that isolated PCL injuries are relatively innocuous and require only conservative treatment is now being questioned. The posterior cruciate ligament is a complex anatomical structure that does not appear to demonstrate the isometric characteristics of its counterpart in the knee, the anterior cruciate ligament. Rather, it consists predominately of a nonisometric anterior bundle that resists posterior displacement of the tibia throughout the majority of knee range of motion. Changes in fiber-bundle length during knee motion appear to be most affected by changes in the femoral attachment site of the PCL graft. When reconstruction of the PCL is being considered, the anterior femoral location should be selected, the graft should be tensioned at ninety degrees of knee flexion, and a anterior tibial force should be applied prior to final graft fixation.","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"317 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132969379","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 : 1900-01-01DOI: 10.1109/SBEC.1995.514509
Dong Xudong, Shi Shujun, Xu Lianlai
The success of implants depends on the properties of the material used. It is important for dental implantology to study and produce implant biomaterials with excellent properties. In this study the relation between heat treatment for 1 hour at 580/spl deg/C after plasma spraying and the crystallinity and solubility of different calcium phosphate coatings is reported. The surface of the coatings were characterized before and after heat treatment after incubation in Gomori's buffer with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The solubility of the different coatings was compared with the degree of crystallinity. The result was that the post-heat treatment influences the degree of both crystallinity and solubility significantly. Incubation of the coatings in Gomori's buffers introduced precipitation at the surface of all non-heat-treated coatings of hydroxyapatite (HA) except fluoroapatite (FA). No precipitation could be observed in any of the heat-treated coatings. FA proved to be more stable than HA. Bond strength between the FA or HA and silicon nitride is higher than that of FA or HA and titanium. There is no significant difference in push-out tests of FA and HA.
{"title":"Study on plasma sprayed coating of bioactive ceramics onto silicon nitride as implant biomaterials","authors":"Dong Xudong, Shi Shujun, Xu Lianlai","doi":"10.1109/SBEC.1995.514509","DOIUrl":"https://doi.org/10.1109/SBEC.1995.514509","url":null,"abstract":"The success of implants depends on the properties of the material used. It is important for dental implantology to study and produce implant biomaterials with excellent properties. In this study the relation between heat treatment for 1 hour at 580/spl deg/C after plasma spraying and the crystallinity and solubility of different calcium phosphate coatings is reported. The surface of the coatings were characterized before and after heat treatment after incubation in Gomori's buffer with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The solubility of the different coatings was compared with the degree of crystallinity. The result was that the post-heat treatment influences the degree of both crystallinity and solubility significantly. Incubation of the coatings in Gomori's buffers introduced precipitation at the surface of all non-heat-treated coatings of hydroxyapatite (HA) except fluoroapatite (FA). No precipitation could be observed in any of the heat-treated coatings. FA proved to be more stable than HA. Bond strength between the FA or HA and silicon nitride is higher than that of FA or HA and titanium. There is no significant difference in push-out tests of FA and HA.","PeriodicalId":332563,"journal":{"name":"Proceedings of the 1995 Fourteenth Southern Biomedical Engineering Conference","volume":"27 14","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120835914","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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