Active rehabilitation training method can help stroke patients recover better and faster. However, the lower limb rehabilitation robot based on electroencephalogram (EEG) has low recognition accuracy now. A classification method based on EEG signals of motor imagery is proposed to enable patients to accurately control their left and right legs. Firstly, aiming at the unstable characteristics of EEG signals, an experimental protocl of motor imagery was constructed based on multi-joint motion coupling of left and right legs. The signals with time-frequency analysis and ERD/S analysis have proved the reliability and validity of the collected EEG signals. Then, the EEG signals generated by the protocol were preprocessed and Common Space Pattern (CSP) was used to extract their features. Support Vector Machine (SVM) and Linear Discriminant Analysis (LDA) are adapted and their accuracy of classification results are compared. Finally, on the basis of the proposed classifier with excellent performance, the classifier is used in the active control strategy of the lower limb rehabilitation robot, and the experiment verified that the average accuracy of two volunteers in controlling the lower limb rehabilitation robot reached 95.1%. This research provides a good theoretical basis for the realization and application of brain-computer interface in rehabilitation training.
{"title":"Research on Movement Intentions of Human's Left and Right Legs Based on EEG Signals","authors":"Fangyan Dong, Liangdan Wu, Yongfei Feng, Dongtai Liang","doi":"10.1115/1.4055435","DOIUrl":"https://doi.org/10.1115/1.4055435","url":null,"abstract":"\u0000 Active rehabilitation training method can help stroke patients recover better and faster. However, the lower limb rehabilitation robot based on electroencephalogram (EEG) has low recognition accuracy now. A classification method based on EEG signals of motor imagery is proposed to enable patients to accurately control their left and right legs. Firstly, aiming at the unstable characteristics of EEG signals, an experimental protocl of motor imagery was constructed based on multi-joint motion coupling of left and right legs. The signals with time-frequency analysis and ERD/S analysis have proved the reliability and validity of the collected EEG signals. Then, the EEG signals generated by the protocol were preprocessed and Common Space Pattern (CSP) was used to extract their features. Support Vector Machine (SVM) and Linear Discriminant Analysis (LDA) are adapted and their accuracy of classification results are compared. Finally, on the basis of the proposed classifier with excellent performance, the classifier is used in the active control strategy of the lower limb rehabilitation robot, and the experiment verified that the average accuracy of two volunteers in controlling the lower limb rehabilitation robot reached 95.1%. This research provides a good theoretical basis for the realization and application of brain-computer interface in rehabilitation training.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47492728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evan Heatherington, Xiaoyue Zhao, N. Goyal, Z. Ounaies, M. Frecker
Aerosols generated during endoscopic sinus procedures present a concern to the health and safety of healthcare personnel especially with the presence of COVID-19. The purpose of this study is to describe the design and testing of a nasal cover to restrict aerosolized pathogens. The nasal cover was designed to sit overtop the nose with conformal slits for insertion of endoscopic instrumentation. Polydimethylsiloxane (PDMS) was chosen as the nasal mask material and its composition, thickness, and slit geometry were selected using a Taguchi experimental design and survey with clinical collaborators at Penn State Milton S. Hershey Medical Center. The nasal cover was designed using principles of origami engineering to be manufactured flat then folded into its operating state. Form and functionality were evaluated by surgeons, fellows, and residents in the aforementioned survey. Aerosol containment was evaluated by measuring smoke, representative of surgical aerosols, with an optical particle counter. A 25:1 composition PDMS with 3mm thickness and vertical slit geometry was chosen for the nasal cover design. Survey results demonstrated that the origami cover sat well on the nose and did not significantly impact the surgical conditions with single instrumentation. On average, this nasal cover was found to restrict more than 93% of 0.3µm aerosols, and more than 99% of all aerosols larger than 0.5µm in size. Use of a patient worn nasal cover has the potential to drastically reduce the risk to hospital personnel during endonasal surgeries by reducing aerosol generation and potential pathogen spread.
{"title":"On the Design and Testing of an Origami Inspired Nasal Cover: Mitigating Aerosol Risks During Endoscopic Sinus Procedures","authors":"Evan Heatherington, Xiaoyue Zhao, N. Goyal, Z. Ounaies, M. Frecker","doi":"10.1115/1.4055251","DOIUrl":"https://doi.org/10.1115/1.4055251","url":null,"abstract":"\u0000 Aerosols generated during endoscopic sinus procedures present a concern to the health and safety of healthcare personnel especially with the presence of COVID-19. The purpose of this study is to describe the design and testing of a nasal cover to restrict aerosolized pathogens. The nasal cover was designed to sit overtop the nose with conformal slits for insertion of endoscopic instrumentation. Polydimethylsiloxane (PDMS) was chosen as the nasal mask material and its composition, thickness, and slit geometry were selected using a Taguchi experimental design and survey with clinical collaborators at Penn State Milton S. Hershey Medical Center. The nasal cover was designed using principles of origami engineering to be manufactured flat then folded into its operating state. Form and functionality were evaluated by surgeons, fellows, and residents in the aforementioned survey. Aerosol containment was evaluated by measuring smoke, representative of surgical aerosols, with an optical particle counter. A 25:1 composition PDMS with 3mm thickness and vertical slit geometry was chosen for the nasal cover design. Survey results demonstrated that the origami cover sat well on the nose and did not significantly impact the surgical conditions with single instrumentation. On average, this nasal cover was found to restrict more than 93% of 0.3µm aerosols, and more than 99% of all aerosols larger than 0.5µm in size. Use of a patient worn nasal cover has the potential to drastically reduce the risk to hospital personnel during endonasal surgeries by reducing aerosol generation and potential pathogen spread.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46127152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mouna Ben Salem, Guillaume Aiche, Y. Haddab, L. Rubbert, P. Renaud
The diagnosis and the treatment of gastrointestinal pathologies have experienced significant development in recent years with the invention of endoscopic capsules which facilitate the access to different sections of the gastrointestinal tract. At a research level, the concept of capsules has been used to perform several functions such as gastrointestinal tract inspection and drug delivery. Despite that, microbiota sampling still requires surgery in order to collect intestinal liquid samples. In this paper, we propose a microbiota sampling device that navigates through the gastrointestinal tract, takes a sample of the intestinal liquid and protects it from any contamination as the device navigates out of the human body. We use a bistable structure to close the capsule after sampling actuated by a foam. The device is safe for the human body and eco friendly, as it does not contain electronic components, batteries and does not require any external intervention. To manufacture the microbiota sampling capsule, we use additive manufacturing. This technology allows fast prototyping cycle at a relatively low cost. It also offers the use of biocompatible material in advanced stages of development.
{"title":"Microbiota Sampling Capsule: Design, Prototyping and Assessment of a Sealing Solution Based on a Bistable Mechanism","authors":"Mouna Ben Salem, Guillaume Aiche, Y. Haddab, L. Rubbert, P. Renaud","doi":"10.1115/1.4055250","DOIUrl":"https://doi.org/10.1115/1.4055250","url":null,"abstract":"\u0000 The diagnosis and the treatment of gastrointestinal pathologies have experienced significant development in recent years with the invention of endoscopic capsules which facilitate the access to different sections of the gastrointestinal tract. At a research level, the concept of capsules has been used to perform several functions such as gastrointestinal tract inspection and drug delivery. Despite that, microbiota sampling still requires surgery in order to collect intestinal liquid samples. In this paper, we propose a microbiota sampling device that navigates through the gastrointestinal tract, takes a sample of the intestinal liquid and protects it from any contamination as the device navigates out of the human body. We use a bistable structure to close the capsule after sampling actuated by a foam. The device is safe for the human body and eco friendly, as it does not contain electronic components, batteries and does not require any external intervention. To manufacture the microbiota sampling capsule, we use additive manufacturing. This technology allows fast prototyping cycle at a relatively low cost. It also offers the use of biocompatible material in advanced stages of development.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46347609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Edward Shi, Leo Lou, Linnea Warburton, B. Rubinsky
A 3D printing technology that facilitates continuous printing along a combination of cartesian and curvilinear coordinates, designed for in vivo and in situ bioprinting is introduced. The combined cartesian/curvilinear printing head motion is accomplished by attaching a biomimetic, flexible, "tendon cable" soft robot arm to a conventional cartesian three axis 3D printing carousel. This allows printing along a combination of cartesian and curvilinear coordinates using five independent stepper motors controlled by an Arduino Uno with each motor requiring a microstep driver powered via a 12V power supply. Three of the independent motors control the printing head motion along conventional cartesian coordinates while two of the independent motors control the length of each pair of the four "tendon cables" which in turn controls the radius of curvature and the angle displacement of the soft printer head along two orthogonal planes. This combination imparts motion along six independent degrees of freedom in cartesian and curvilinear coordinates. The design of the system is described together with experimental results which demonstrate that this design can print continuously along curved and inclined surfaces while avoiding the "staircase" effect, which is typical of conventional three axis 3D printing along curvilinear surfaces.
{"title":"3D Printing in Combined Cartesian and Curvilinear Coordinates","authors":"Edward Shi, Leo Lou, Linnea Warburton, B. Rubinsky","doi":"10.1115/1.4055064","DOIUrl":"https://doi.org/10.1115/1.4055064","url":null,"abstract":"\u0000 A 3D printing technology that facilitates continuous printing along a combination of cartesian and curvilinear coordinates, designed for in vivo and in situ bioprinting is introduced. The combined cartesian/curvilinear printing head motion is accomplished by attaching a biomimetic, flexible, \"tendon cable\" soft robot arm to a conventional cartesian three axis 3D printing carousel. This allows printing along a combination of cartesian and curvilinear coordinates using five independent stepper motors controlled by an Arduino Uno with each motor requiring a microstep driver powered via a 12V power supply. Three of the independent motors control the printing head motion along conventional cartesian coordinates while two of the independent motors control the length of each pair of the four \"tendon cables\" which in turn controls the radius of curvature and the angle displacement of the soft printer head along two orthogonal planes. This combination imparts motion along six independent degrees of freedom in cartesian and curvilinear coordinates. The design of the system is described together with experimental results which demonstrate that this design can print continuously along curved and inclined surfaces while avoiding the \"staircase\" effect, which is typical of conventional three axis 3D printing along curvilinear surfaces.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42704362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reverse shoulder arthroplasty (RSA) is used to treat patients with cuff tear arthropathy. Loosening remains one of the principal modes of implant failure and the main complication leading to revision. Excess micromotion contributes to glenoid loosening. This study assessed the predictive accuracy of an experimental system designed to assess factors contributing to RSA glenoid baseplate micromotion. A half-fractional factorial experiment was designed to assess 4 factors: central element type (screw vs. peg), central element length (13.5 vs. 23.5 mm), anterior posterior peripheral screw type (locking vs. nonlocking) and cancellous bone density (10 vs. 25 pounds per cubic foot [pcf]). Four linear variable differential transducers (LVDTs) recorded micromotion from a stainless-steel disc surrounding a modified glenosphere. The displacements were used to interpolate micromotion at each of the respective peripheral screw positions. The mean absolute percentage error (MAPE) was used to determine the predictive accuracy and error range of the system. The MAPE for each condition ranged from 6.8% to 12.9% for an overall MAPE of (9.5±0.9)%. The system had an error range of 2.7 µm to 20.1 µm, which was lower than those reported by prior studies using optical systems. One of the eight conditions had micromotion that exceeded 150 µm. These findings support the use of displacement transducers, specifically LVDTs, as an accurate system for determining RSA baseplate micromotion in rigid polyurethane foam bone surrogates.
{"title":"Accuracy of an Apparatus for Measuring Glenoid Baseplate Micromotion in Reverse Shoulder Arthroplasty","authors":"L. Torkan, J. T. Bryant, R. Bicknell, H. Ploeg","doi":"10.1115/1.4055063","DOIUrl":"https://doi.org/10.1115/1.4055063","url":null,"abstract":"\u0000 Reverse shoulder arthroplasty (RSA) is used to treat patients with cuff tear arthropathy. Loosening remains one of the principal modes of implant failure and the main complication leading to revision. Excess micromotion contributes to glenoid loosening. This study assessed the predictive accuracy of an experimental system designed to assess factors contributing to RSA glenoid baseplate micromotion. A half-fractional factorial experiment was designed to assess 4 factors: central element type (screw vs. peg), central element length (13.5 vs. 23.5 mm), anterior posterior peripheral screw type (locking vs. nonlocking) and cancellous bone density (10 vs. 25 pounds per cubic foot [pcf]). Four linear variable differential transducers (LVDTs) recorded micromotion from a stainless-steel disc surrounding a modified glenosphere. The displacements were used to interpolate micromotion at each of the respective peripheral screw positions. The mean absolute percentage error (MAPE) was used to determine the predictive accuracy and error range of the system. The MAPE for each condition ranged from 6.8% to 12.9% for an overall MAPE of (9.5±0.9)%. The system had an error range of 2.7 µm to 20.1 µm, which was lower than those reported by prior studies using optical systems. One of the eight conditions had micromotion that exceeded 150 µm. These findings support the use of displacement transducers, specifically LVDTs, as an accurate system for determining RSA baseplate micromotion in rigid polyurethane foam bone surrogates.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46742864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A proof-of-concept, fully automated, mass-customization pipeline for knee replacement surgery is outlined. The pipeline aims to address the limitations of currently available customization solutions by removing the need for 3D imaging and manual design, minimizing lead times, and reducing costs, whilst enabling improved patient outcomes. The dataflow of the pipeline and methods for assessing performance are detailed. A digitally reconstructed radiograph method was adopted in the analysis to remove errors stemming from poor X-ray alignment and calibration, and to enable the influence of specific attributes to be evaluated. A sensitivity study was performed to quantify the impact of X-ray alignment and calibration. The analysis found better results were achieved for the tibia over the femur in terms of clinically significant component over/under-hang (9% vs 18%). The pipeline was sensitive to subject ethnicity, but this was likely due to limited diversity in the training data. Arthritis severity was found to impact performance, suggesting further work is required to confirm suitability for use with more severe cases. X-ray alignment and dimensional calibration were shown to be paramount for accurate results. The pipeline performance was demonstrated to be superior to results reported for off-the-shelf implants, but customization solutions based on 3D imaging could afford marginally better results. In summary, the study validated the pipeline for a broad range of subjects, highlighted its potential advantages over both off-the-shelf and other customization alternatives, and outlined the potential challenges of adopting such a tool.
概述了一种概念验证、全自动、大规模定制的膝关节置换手术管道。该管道旨在通过消除对3D成像和人工设计的需求，最大限度地缩短交货时间，降低成本，同时改善患者的治疗效果，从而解决当前可用定制解决方案的局限性。详细介绍了管道的数据流和性能评估方法。在分析中采用了数字重建的x线照片方法，以消除由于x线对准和校准不良而产生的误差，并能够评估特定属性的影响。进行了灵敏度研究，以量化x射线对准和校准的影响。分析发现，就临床意义部件的上/下悬挂而言，胫骨优于股骨(9% vs 18%)。管道对受试者种族敏感，但这可能是由于培训数据的多样性有限。发现关节炎的严重程度会影响性能，这表明需要进一步的工作来确认在更严重的情况下使用的适用性。x射线对准和尺寸校准被证明是最重要的准确结果。管道性能被证明优于现成的植入物，但基于3D成像的定制解决方案可以提供稍微更好的结果。总之，该研究验证了管道的广泛主题，强调了其相对于现成的和其他定制替代方案的潜在优势，并概述了采用这种工具的潜在挑战。
{"title":"Performance and Sensitivity Analysis of an Automated X-Ray Based Total Knee Replacement Mass-Customization Pipeline","authors":"T. A. Burge, J. Jeffers, C. Myant","doi":"10.1115/1.4055000","DOIUrl":"https://doi.org/10.1115/1.4055000","url":null,"abstract":"\u0000 A proof-of-concept, fully automated, mass-customization pipeline for knee replacement surgery is outlined. The pipeline aims to address the limitations of currently available customization solutions by removing the need for 3D imaging and manual design, minimizing lead times, and reducing costs, whilst enabling improved patient outcomes.\u0000 The dataflow of the pipeline and methods for assessing performance are detailed. A digitally reconstructed radiograph method was adopted in the analysis to remove errors stemming from poor X-ray alignment and calibration, and to enable the influence of specific attributes to be evaluated. A sensitivity study was performed to quantify the impact of X-ray alignment and calibration.\u0000 The analysis found better results were achieved for the tibia over the femur in terms of clinically significant component over/under-hang (9% vs 18%). The pipeline was sensitive to subject ethnicity, but this was likely due to limited diversity in the training data. Arthritis severity was found to impact performance, suggesting further work is required to confirm suitability for use with more severe cases. X-ray alignment and dimensional calibration were shown to be paramount for accurate results. The pipeline performance was demonstrated to be superior to results reported for off-the-shelf implants, but customization solutions based on 3D imaging could afford marginally better results.\u0000 In summary, the study validated the pipeline for a broad range of subjects, highlighted its potential advantages over both off-the-shelf and other customization alternatives, and outlined the potential challenges of adopting such a tool.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48801554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Early onset scoliosis (EOS) is a type of spine deformity that presents before 10 years of age. The biomechanical properties in scoliosis have been found to be di?erent, especially in the case of the concave and convex paraverte-bral muscles. Based on this fact, a novel 3d printed patient-specific asymmetric stiffness brace design method is proposed in this paper, aiming to provide asymmetric stiffness to match "imbalanced" biomechanical properties of the concave and convex paravertebral muscles, respectively, and treat EOS by applying the block-structure brace.A 3d CAD draft model of the brace contour was implemented from 3D scanning. The asymmetric stiffness block-structure brace was designed in Rhinoceros and the Finite Ele-ment (FE) model was imported into ABAQUS. FE simulation was employed to study the mechanical characteristics of the brace, which provided a quan-titative index for the "imbalanced" property of brace stiffness. The results of the FE simulation showed that the stiffnesses of the concave and convex sides were 145.88 N/mm and 35.95 N/mm, respectively. The block-structure brace was fabricated using 3d printing. Asymmetric stiffness was evaluated by corrective force measurements, which were obtained from a thin-film pressure sensor equipped on the brace. The patient-specific asymmetric stiffness brace was applied to clinical practice in a one-year old EOS patient. A novel low-cost 3D printed brace design method for EOS was proposed in this study that could potentially be useful in patient treatment acceptance.
{"title":"A Novel Low-Cost 3D Printed Brace Design Method for Early Onset Scoliosis","authors":"Hongwei Li, Zhangkai Yang, Dichen Li, F. Qiao","doi":"10.1115/1.4054998","DOIUrl":"https://doi.org/10.1115/1.4054998","url":null,"abstract":"\u0000 Early onset scoliosis (EOS) is a type of spine deformity that presents before 10 years of age. The biomechanical properties in scoliosis have been found to be di?erent, especially in the case of the concave and convex paraverte-bral muscles. Based on this fact, a novel 3d printed patient-specific asymmetric stiffness brace design method is proposed in this paper, aiming to provide asymmetric stiffness to match \"imbalanced\" biomechanical properties of the concave and convex paravertebral muscles, respectively, and treat EOS by applying the block-structure brace.A 3d CAD draft model of the brace contour was implemented from 3D scanning. The asymmetric stiffness block-structure brace was designed in Rhinoceros and the Finite Ele-ment (FE) model was imported into ABAQUS. FE simulation was employed to study the mechanical characteristics of the brace, which provided a quan-titative index for the \"imbalanced\" property of brace stiffness. The results of the FE simulation showed that the stiffnesses of the concave and convex sides were 145.88 N/mm and 35.95 N/mm, respectively. The block-structure brace was fabricated using 3d printing. Asymmetric stiffness was evaluated by corrective force measurements, which were obtained from a thin-film pressure sensor equipped on the brace. The patient-specific asymmetric stiffness brace was applied to clinical practice in a one-year old EOS patient. A novel low-cost 3D printed brace design method for EOS was proposed in this study that could potentially be useful in patient treatment acceptance.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49221053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Artificial anal sphincter has gradually become an emerging means of treating anal incontinence. However, most of the systems cannot be implanted in the human body for a long time due to insufficient reliability. Therefore, this paper has designed and improved a novel bionic artificial anal sphincter (BAAS). In order to make it work reliably for a long time, we first optimized and improved key parts to increase their strength. Given the humid working environment in the body, we optimized the design of the waterproof pressure sensor and carried out experimental research on the sealing of the circuit board and the overall sealing. When evaluating the improved system, I used simulation to analyze the structural strength and motion characteristics of the BAAS and used underwater experiments to simulate the human environment to evaluate the waterproofness of the system. The results showed that the strength of the key joint increased by 49.4%, the average clamping time and opening time of the prosthesis were 14.5s and 13.4s, respectively, and the angular velocity of the pendulum rod approaching the intestine was about 4.5°/s, which was in line with the normal defecation process of the human body. The performance is stable and reliable in the 20-day underwater body fluid simulation experiment. BAAS basically meets the application needs of long-term implantation in the treatment of fecal incontinence.
{"title":"Design, Improvement and Evaluation of a Novel in Situ Implanted Bionic Artificial Anal Sphincter","authors":"Lichao Wang, G. Yan, Ding Han, Dasheng Liu, Fangfang Hua, Tong Wu","doi":"10.1115/1.4055001","DOIUrl":"https://doi.org/10.1115/1.4055001","url":null,"abstract":"\u0000 Artificial anal sphincter has gradually become an emerging means of treating anal incontinence. However, most of the systems cannot be implanted in the human body for a long time due to insufficient reliability. Therefore, this paper has designed and improved a novel bionic artificial anal sphincter (BAAS). In order to make it work reliably for a long time, we first optimized and improved key parts to increase their strength. Given the humid working environment in the body, we optimized the design of the waterproof pressure sensor and carried out experimental research on the sealing of the circuit board and the overall sealing. When evaluating the improved system, I used simulation to analyze the structural strength and motion characteristics of the BAAS and used underwater experiments to simulate the human environment to evaluate the waterproofness of the system. The results showed that the strength of the key joint increased by 49.4%, the average clamping time and opening time of the prosthesis were 14.5s and 13.4s, respectively, and the angular velocity of the pendulum rod approaching the intestine was about 4.5°/s, which was in line with the normal defecation process of the human body. The performance is stable and reliable in the 20-day underwater body fluid simulation experiment. BAAS basically meets the application needs of long-term implantation in the treatment of fecal incontinence.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48436624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jeong-Yeon Park, Dong-won Lee, Sunray Lee, Dong-Mok Lee, Jienny Lee, Hyun-sook Park, G. Yoon
With advances in biotechnology, the field of cryopreservation has been continuously developed and improved. Typical cryo-container was designed with minimal flow to avoid possible structural defects in LN2 tank, which has a higher thermal conductivity than vapor nitrogen tank. If cells are placed in typical cryo-container and stored in VN2 tank, cross-contamination can be prevented, but the cell viability after thawing may be reduced. The structure of typical cryo-containers are not optimized for vaporized nitrogen to flow quickly into the container and its circulation well. Therefore, we proposed new cryo-container models that can maintain mechanical strength while optimizing the fluid flow structure, and performed thermal-structural coupled field analysis on cryo-containers. We confirmed the cryo-containers by comparing the equivalent stress distributions formed around through holes and evaluating thermal equilibrium in the cryogenic steady state through flow analysis. Prototype cryo-containers and typical cryo-containers were placed in VN2 tank for a period of time to observe temperature changes. As a result, the time it takes to reach the temperature equilibrium has been reduced to 55% level compared with the typical cryo-containers. Additionally, C2C12 and hADMSC cells were checked after storage under two temperature conditions (-80 and -196°C). In both cell, viability, adhesion and relative cell proliferation were improved by up to 15-20% in new containers compared to typical products. The developed container is expected to maintain stability well by being applied to storage and transportation of advanced medicines that require cryopreservation.
{"title":"Comparison of Temperature Equilibrium Rate and Cell Growth/Viability Under Air Circulation in Cryogenic Storage Container","authors":"Jeong-Yeon Park, Dong-won Lee, Sunray Lee, Dong-Mok Lee, Jienny Lee, Hyun-sook Park, G. Yoon","doi":"10.1115/1.4054833","DOIUrl":"https://doi.org/10.1115/1.4054833","url":null,"abstract":"\u0000 With advances in biotechnology, the field of cryopreservation has been continuously developed and improved. Typical cryo-container was designed with minimal flow to avoid possible structural defects in LN2 tank, which has a higher thermal conductivity than vapor nitrogen tank. If cells are placed in typical cryo-container and stored in VN2 tank, cross-contamination can be prevented, but the cell viability after thawing may be reduced. The structure of typical cryo-containers are not optimized for vaporized nitrogen to flow quickly into the container and its circulation well. Therefore, we proposed new cryo-container models that can maintain mechanical strength while optimizing the fluid flow structure, and performed thermal-structural coupled field analysis on cryo-containers. We confirmed the cryo-containers by comparing the equivalent stress distributions formed around through holes and evaluating thermal equilibrium in the cryogenic steady state through flow analysis. Prototype cryo-containers and typical cryo-containers were placed in VN2 tank for a period of time to observe temperature changes. As a result, the time it takes to reach the temperature equilibrium has been reduced to 55% level compared with the typical cryo-containers. Additionally, C2C12 and hADMSC cells were checked after storage under two temperature conditions (-80 and -196°C). In both cell, viability, adhesion and relative cell proliferation were improved by up to 15-20% in new containers compared to typical products. The developed container is expected to maintain stability well by being applied to storage and transportation of advanced medicines that require cryopreservation.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48316877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
People who frequently use micropipettes experience hand and upper limb disorders. The basilar thumb joint, also known as the first carpometacarpal or trapeziometacarpal joint, is commonly affected by osteoarthritis (OA). Mechanical factors are associated with OA initiation and progression. We developed a MRI-compatible modular micropipette simulator to improve understanding of how micropipette design affects basilar thumb joint contact mechanics. The micropipette simulator also addresses limitations of current techniques for studying pipetting and basilar thumb joint mechanics. Its modularity will allow future studies to examine handle design parameters such as handle diameter, cross-sectional shape, and other features. A micropipette simulator with a cylindrical handle (length 127 mm, diameter 25 mm) was used with one subject to demonstrate the system's feasibility. Contact areas were within the range of prior data from basilar thumb joint models in power grasp and lateral pinch, and contact pressures were the same order of magnitude.
{"title":"A Modular MRI-Compatible Pipette Simulator to Evaluate How Design Effects the Basilar Thumb Joint Mechanics","authors":"Nolan M. Norton, K. Fischer","doi":"10.1115/1.4054725","DOIUrl":"https://doi.org/10.1115/1.4054725","url":null,"abstract":"\u0000 People who frequently use micropipettes experience hand and upper limb disorders. The basilar thumb joint, also known as the first carpometacarpal or trapeziometacarpal joint, is commonly affected by osteoarthritis (OA). Mechanical factors are associated with OA initiation and progression. We developed a MRI-compatible modular micropipette simulator to improve understanding of how micropipette design affects basilar thumb joint contact mechanics. The micropipette simulator also addresses limitations of current techniques for studying pipetting and basilar thumb joint mechanics. Its modularity will allow future studies to examine handle design parameters such as handle diameter, cross-sectional shape, and other features. A micropipette simulator with a cylindrical handle (length 127 mm, diameter 25 mm) was used with one subject to demonstrate the system's feasibility. Contact areas were within the range of prior data from basilar thumb joint models in power grasp and lateral pinch, and contact pressures were the same order of magnitude.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45523638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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