I. Mohedas, Carrie Bell, Betregiorgis Hailu Zegeye, KevinC Jiang, Caroline Soyars, Madeleine Walsh, K. Sienko
Worldwide, 225 million women have unmet contraceptive needs which, every year, leads to 52 million unintended pregnancies. A challenge to providing universal access to contraception is the large proportion of the population living in rural, difficult to access settings in low- and middle-income countries. The availability and delivery of effective contraception in rural areas is limited by the lack of trained healthcare providers. Barriers to the use of long-acting contraceptives in rural areas are more pronounced due to the advanced skill and training to administer. In this study, we describe the design and testing of the SubQ Assist, a task-shifting contraceptive implant insertion device that aims to reduce the training requirements for administering contraceptive implants while simultaneously ensuring safe and high quality administration. Cadaver testing in conjunction with ultrasound depth measurements were used to evaluate the efficacy of the SubQ Assist. Implant insertion between the SubQ Assist and a trained physician are compared. Cadaver testing and ultrasound depth measurements demonstrate that the SubQ Assist results in implant insertions that are statistically equivalent to implants inserted by a trained physician. Additionally, the results show that the lateral positioning of these implants would facilitate uncomplicated removal at a later date. These findings demonstrate proof of concept for the SubQ Assist and provide evidence for moving towards clinical testing. They demonstrate that the SubQ Assist may be an effective method of task-shifting the insertion of contraceptive implants to minimally trained providers in order to expand access in rural areas.
{"title":"Pre-Clinical Evaluation of a Task-Shifting Contraceptive Implant Insertion Device for Use in Low- and Middle-Income Countries","authors":"I. Mohedas, Carrie Bell, Betregiorgis Hailu Zegeye, KevinC Jiang, Caroline Soyars, Madeleine Walsh, K. Sienko","doi":"10.1115/1.4054684","DOIUrl":"https://doi.org/10.1115/1.4054684","url":null,"abstract":"\u0000 Worldwide, 225 million women have unmet contraceptive needs which, every year, leads to 52 million unintended pregnancies. A challenge to providing universal access to contraception is the large proportion of the population living in rural, difficult to access settings in low- and middle-income countries. The availability and delivery of effective contraception in rural areas is limited by the lack of trained healthcare providers. Barriers to the use of long-acting contraceptives in rural areas are more pronounced due to the advanced skill and training to administer. In this study, we describe the design and testing of the SubQ Assist, a task-shifting contraceptive implant insertion device that aims to reduce the training requirements for administering contraceptive implants while simultaneously ensuring safe and high quality administration. Cadaver testing in conjunction with ultrasound depth measurements were used to evaluate the efficacy of the SubQ Assist. Implant insertion between the SubQ Assist and a trained physician are compared. Cadaver testing and ultrasound depth measurements demonstrate that the SubQ Assist results in implant insertions that are statistically equivalent to implants inserted by a trained physician. Additionally, the results show that the lateral positioning of these implants would facilitate uncomplicated removal at a later date. These findings demonstrate proof of concept for the SubQ Assist and provide evidence for moving towards clinical testing. They demonstrate that the SubQ Assist may be an effective method of task-shifting the insertion of contraceptive implants to minimally trained providers in order to expand access in rural areas.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46920206","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}
Alizée Koszulinski, J. Sandoval, T. Vendeuvre, S. Zeghloul, M. Laribi
In this paper, a novel surgical robotic platform intended to assist surgeons in cervical spine surgery is presented. The purpose of this surgery is to treat cervical spine instabilities. The surgical procedure requires drilling into specific region of the vertebrae in order to attach spinal implants and ensure a normal spacing between each vertebra. In this context, the proposed robotic platform allows to control and restrict surgeon's movements to a specific drilling direction set by the surgeon. The current platform is composed of a collaborative robot with 7 DoF equipped with a drilling tool and directly comanipulated by the surgeon. A motion capture system, as an exteroceptive sensor device, provides the robot controller with the movement data of the vertebra to be drilled. Robot Operating System (ROS) framework is used to enable real-time communication between the collaborative robot and the visual exteroceptive device. In addition, an implemented compliance control program allows to enhance the safety aspect of the robotic platform. Indeed, the collaborative robot follow the patient's movements while constraining the tool movements to an optimal trajectory as well as a limited drilling depth selected by the surgeon. The robot's elbow movements are also restricted by exploiting the null-space in order to avoid collisions with other equipment or medical team members. Experimental drilling trials have been performed by an orthopedic surgeon to validate the usefulness and different functionalities of the developed robotic platform, and provide that a collaborative robot can comply with spine surgery procedure.
{"title":"Comanipulation Robotic Platform for Spine Surgery with Exteroceptive Visual Coupling: Development and Experimentation","authors":"Alizée Koszulinski, J. Sandoval, T. Vendeuvre, S. Zeghloul, M. Laribi","doi":"10.1115/1.4054550","DOIUrl":"https://doi.org/10.1115/1.4054550","url":null,"abstract":"\u0000 In this paper, a novel surgical robotic platform intended to assist surgeons in cervical spine surgery is presented. The purpose of this surgery is to treat cervical spine instabilities. The surgical procedure requires drilling into specific region of the vertebrae in order to attach spinal implants and ensure a normal spacing between each vertebra. In this context, the proposed robotic platform allows to control and restrict surgeon's movements to a specific drilling direction set by the surgeon. The current platform is composed of a collaborative robot with 7 DoF equipped with a drilling tool and directly comanipulated by the surgeon. A motion capture system, as an exteroceptive sensor device, provides the robot controller with the movement data of the vertebra to be drilled. Robot Operating System (ROS) framework is used to enable real-time communication between the collaborative robot and the visual exteroceptive device. In addition, an implemented compliance control program allows to enhance the safety aspect of the robotic platform. Indeed, the collaborative robot follow the patient's movements while constraining the tool movements to an optimal trajectory as well as a limited drilling depth selected by the surgeon. The robot's elbow movements are also restricted by exploiting the null-space in order to avoid collisions with other equipment or medical team members. Experimental drilling trials have been performed by an orthopedic surgeon to validate the usefulness and different functionalities of the developed robotic platform, and provide that a collaborative robot can comply with spine surgery procedure.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45983880","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}
Yazan M. Dweiri, Abdullah F. Al-Dwairi, Mousa Al-Zanina, Reham Al Diabat
This work aims to introduce simple-to-implement modifications to the elliptical trainer device to increase its utility with added new exercise options. The effectiveness of the introduced modifications was assessed on 51 subjects, with effectiveness representing the recruitment of a broader range of muscle groups with desired intensity levels. The improvements include a new in-phase mode, where bilateral body synchronization creates a skiing-like motion, and a variable range of motion through adjusting the stride length of a rotating-link mechanism. The impact of these modifications on muscle recruitment was assessed by recording surface electromyogram (sEMG) from eleven major muscles while performing a total of six exercise routines. The routines have various combinations of mode and intensity to cover the traditional mechanism and the newly- introduced mechanism adjustments for comparative analysis. The results have shown that increasing the stride length increases the demand on lower limbs muscles during the anti-phase mode while decreasing it on upper limb muscles. When comparing the two exercise modes, all muscle groups showed significantly higher activity in the in-phase mode except for thigh muscles (Hamstrings and Quadriceps). Hamstrings revealed significantly higher activity in the anti-phase mode, while Quadriceps showed no significantly different activity between the two modes. The introduced design modifications are shown to diversify the demand on major skeletal muscles hence improving its functionality at low added cost. Furthermore, these results can be exploited to implement gradual physiotherapeutic rehabilitation plans targeting various muscle groups with desired intensity levels.
{"title":"Elliptical Trainer Redesign to Diversify Muscles Recruitment","authors":"Yazan M. Dweiri, Abdullah F. Al-Dwairi, Mousa Al-Zanina, Reham Al Diabat","doi":"10.1115/1.4054548","DOIUrl":"https://doi.org/10.1115/1.4054548","url":null,"abstract":"\u0000 This work aims to introduce simple-to-implement modifications to the elliptical trainer device to increase its utility with added new exercise options. The effectiveness of the introduced modifications was assessed on 51 subjects, with effectiveness representing the recruitment of a broader range of muscle groups with desired intensity levels. The improvements include a new in-phase mode, where bilateral body synchronization creates a skiing-like motion, and a variable range of motion through adjusting the stride length of a rotating-link mechanism.\u0000 The impact of these modifications on muscle recruitment was assessed by recording surface electromyogram (sEMG) from eleven major muscles while performing a total of six exercise routines. The routines have various combinations of mode and intensity to cover the traditional mechanism and the newly- introduced mechanism adjustments for comparative analysis.\u0000 The results have shown that increasing the stride length increases the demand on lower limbs muscles during the anti-phase mode while decreasing it on upper limb muscles. When comparing the two exercise modes, all muscle groups showed significantly higher activity in the in-phase mode except for thigh muscles (Hamstrings and Quadriceps). Hamstrings revealed significantly higher activity in the anti-phase mode, while Quadriceps showed no significantly different activity between the two modes.\u0000 The introduced design modifications are shown to diversify the demand on major skeletal muscles hence improving its functionality at low added cost. Furthermore, these results can be exploited to implement gradual physiotherapeutic rehabilitation plans targeting various muscle groups with desired intensity levels.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44497712","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 shock wave-driven needle-free syringe was developed and tested for liquid jet delivery into an artificial skin model and porcine skin samples. The device could deliver an adequate volume of liquid to a depth sufficient for drug dissemination in skin samples. The device is equipped with a splash-proof conduit and a silencer for smooth operation. The concept is expected to minimize the pain of liquid injection by a) minimally breaching the blood vessels in the skin, b) reducing trauma, inflammation and aiding regeneration of the incised spot by the liquid of the jet, and c) preserving most of the micro-circulation system in the target, enabling an effective drug uptake. A theoretical model that predicts jet penetration into viscoelastic targets is derived and presented. A sound agreement has been observed between the experimental jet penetration depths and the corresponding theoretical predictions. The development can offer a cost-effective, minimally invasive health care solution for immunization and drug delivery.
{"title":"High-Speed Jet Injector for Pharmaceutical Applications","authors":"Priyanka Hankare, Ashish Agrawala, V. Menezes","doi":"10.1115/1.4054549","DOIUrl":"https://doi.org/10.1115/1.4054549","url":null,"abstract":"\u0000 A shock wave-driven needle-free syringe was developed and tested for liquid jet delivery into an artificial skin model and porcine skin samples. The device could deliver an adequate volume of liquid to a depth sufficient for drug dissemination in skin samples. The device is equipped with a splash-proof conduit and a silencer for smooth operation. The concept is expected to minimize the pain of liquid injection by a) minimally breaching the blood vessels in the skin, b) reducing trauma, inflammation and aiding regeneration of the incised spot by the liquid of the jet, and c) preserving most of the micro-circulation system in the target, enabling an effective drug uptake. A theoretical model that predicts jet penetration into viscoelastic targets is derived and presented. A sound agreement has been observed between the experimental jet penetration depths and the corresponding theoretical predictions. The development can offer a cost-effective, minimally invasive health care solution for immunization and drug delivery.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43131626","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}
G. Villalba-Alumbreros, Carlos Moron-Alguacil, M. Fernández-Muñoz, I. Valiente-Blanco, E. Díez-Jiménez
This paper theoretically analyses the miniaturization effects on torque, efficiency and thermal behaviour of high torque permanent magnet BLDC motors with ferromagnetic core coils for internal medical devices. Using a finite element model of a 2-phase BLDC motor, scalability laws are provided for diameters between 0.1 and 100 mm and current densities between 1 and 1000 A/mm2. Based in the impact of the cogging torque and overheating of the motor, scale dependent operational limits are calculated. Operational threshold can be determined at the point where cogging torque becomes dominating over total torque, limiting the use of traditional iron-core motors in the micro-scale. To overcome such limitation, a potential solution is to increase the current density in the windings. However, overheating of the motor limits such increase in the current density which is critical for internal medical applications. Current density limits are provided based on three representative in-body thermal scenarios: respiratory tract, body fluid and blood torrent. Maximum current densities and corresponding torque and efficiency have been obtained for different micro-motor sizes considering safe in-body operation as threshold. It is demonstrated the potential application of micro-motors in internal body environments with acceptable performance for sizes down to 0.1 mm diameter.
本文从理论上分析了医用高转矩铁磁铁芯线圈永磁无刷直流电机的小型化对转矩、效率和热性能的影响。利用两相无刷直流电机的有限元模型，给出了直径在0.1到100 mm之间，电流密度在1到1000 a /mm2之间的可扩展性规律。基于齿槽转矩和电机过热的影响，计算出与刻度相关的运行极限。当齿槽转矩占总转矩的主导地位时，可以确定运行阈值，这限制了传统铁芯电机在微尺度下的使用。为了克服这种限制，一个可能的解决方案是增加绕组中的电流密度。然而，电机过热限制了电流密度的增加，这对内部医疗应用至关重要。基于呼吸道、体液和血流三种具有代表性的体内热情景，给出了电流密度限制。以安全运行为阈值，得到了不同微电机尺寸的最大电流密度及相应的转矩和效率。这证明了微型电机在内部身体环境中的潜在应用，其性能可接受，直径小至0.1毫米。
{"title":"Scale Effects on Performance of BLDC Micromotors for Internal Biomedical Applications: a Finite Element Analysis","authors":"G. Villalba-Alumbreros, Carlos Moron-Alguacil, M. Fernández-Muñoz, I. Valiente-Blanco, E. Díez-Jiménez","doi":"10.1115/1.4054495","DOIUrl":"https://doi.org/10.1115/1.4054495","url":null,"abstract":"\u0000 This paper theoretically analyses the miniaturization effects on torque, efficiency and thermal behaviour of high torque permanent magnet BLDC motors with ferromagnetic core coils for internal medical devices. Using a finite element model of a 2-phase BLDC motor, scalability laws are provided for diameters between 0.1 and 100 mm and current densities between 1 and 1000 A/mm2. Based in the impact of the cogging torque and overheating of the motor, scale dependent operational limits are calculated. Operational threshold can be determined at the point where cogging torque becomes dominating over total torque, limiting the use of traditional iron-core motors in the micro-scale. To overcome such limitation, a potential solution is to increase the current density in the windings. However, overheating of the motor limits such increase in the current density which is critical for internal medical applications. Current density limits are provided based on three representative in-body thermal scenarios: respiratory tract, body fluid and blood torrent. Maximum current densities and corresponding torque and efficiency have been obtained for different micro-motor sizes considering safe in-body operation as threshold. It is demonstrated the potential application of micro-motors in internal body environments with acceptable performance for sizes down to 0.1 mm diameter.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42831496","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}
The purpose of this study was to develop an automatic bronchial aspiration system to minimize tracheal mucosal damage in ventilator patients. Operation performances of the system's suction pressure, bronchial intubation depth, suction cycle, and tube cuff pressure were tested. To check clinical results, subjects underwent endoscopy after applying the previous manual method for 24 hours. After that, they underwent endoscopy after applying the proposed suction system for 24 hours. For quantitative evaluation of test results, tracheal mucosal injury was divided into five grades: Grade 0 = normal, Grade 1 = erythema or edema, Grade 2 = erosion, Grade 3 = hemorrhage, and Grade 4 = ulcer or necrosis. In the performance test, an error of up to 12 mmHg occurred within the normal operation error range for suction pressure control. The insertion depth control had a maximum error of 7.0 mm within the normal operation error range. On the other hand, there was no error in the time control or the tube cuff pressure control. In the clinical trial, after using the proposed system for five subjects to find changes in tracheal mucosal injury by endoscopy, reduced injury or no change in injury was found. The system proposed in this study is confirmed to be able to remove sputum while minimizing tracheal mucosal injury that can occur when using previous manual suction device.
{"title":"Study On Device System to Reduce Tracheal Mucosal Injury in Intubation Patients","authors":"Dai Won Suh, Seung Bong Lee, Sung Min Kim","doi":"10.1115/1.4054334","DOIUrl":"https://doi.org/10.1115/1.4054334","url":null,"abstract":"\u0000 The purpose of this study was to develop an automatic bronchial aspiration system to minimize tracheal mucosal damage in ventilator patients. Operation performances of the system's suction pressure, bronchial intubation depth, suction cycle, and tube cuff pressure were tested. To check clinical results, subjects underwent endoscopy after applying the previous manual method for 24 hours. After that, they underwent endoscopy after applying the proposed suction system for 24 hours. For quantitative evaluation of test results, tracheal mucosal injury was divided into five grades: Grade 0 = normal, Grade 1 = erythema or edema, Grade 2 = erosion, Grade 3 = hemorrhage, and Grade 4 = ulcer or necrosis. In the performance test, an error of up to 12 mmHg occurred within the normal operation error range for suction pressure control. The insertion depth control had a maximum error of 7.0 mm within the normal operation error range. On the other hand, there was no error in the time control or the tube cuff pressure control. In the clinical trial, after using the proposed system for five subjects to find changes in tracheal mucosal injury by endoscopy, reduced injury or no change in injury was found. The system proposed in this study is confirmed to be able to remove sputum while minimizing tracheal mucosal injury that can occur when using previous manual suction device.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45704739","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}
Robotic devices are commonly used in surgical simulators to provide tactile, or haptic, feedback. They can provide customized feedback that can be rapidly modified with minimal hardware changes in comparison to non-robotic systems. This work describes the design, development, and evaluation of one such tool: a novel uniaxial torque haptic device for a surgical training simulator. The objective of the work was to design a single connection haptic device that could augment an existing six degree of freedom haptic device to mimic a Concorde Clear vacuum curette. Design and evaluations focused on the tool's ability to deliver adequate torque, imitate a surgical tool, and be integrated into the haptic device. Twenty-nine surgeons tested the tool in the simulator and evaluated it via a questionnaire. The device was found to deliver the 800 N·mm of torque necessary to mimic an orthopedic procedure. Surgeons found it accurately imitated surgical tool physical appearance and maneuverability, scoring them 3.9±1.0 and 3.3±1.2, respectively, on a 1-5 Likert scale. By virtue of the functionality necessary for testing and evaluation, the device could be connected to the haptic device for mechanical and electrical engagement. This device is a step forward in the field of augmentable haptic devices for surgical simulation. By changing the number of robotically-controlled degrees of freedom of a haptic device, existing devices can be tuned to meet the demands of a particular simulator, which has the potential to improve surgeon training standards.
{"title":"Design Synthesis of a Robotic Uniaxial Torque Device for Orthopedic Haptic Simulation","authors":"T. Cotter, R. Mongrain, Mark Driscoll","doi":"10.1115/1.4054344","DOIUrl":"https://doi.org/10.1115/1.4054344","url":null,"abstract":"\u0000 Robotic devices are commonly used in surgical simulators to provide tactile, or haptic, feedback. They can provide customized feedback that can be rapidly modified with minimal hardware changes in comparison to non-robotic systems. This work describes the design, development, and evaluation of one such tool: a novel uniaxial torque haptic device for a surgical training simulator. The objective of the work was to design a single connection haptic device that could augment an existing six degree of freedom haptic device to mimic a Concorde Clear vacuum curette. Design and evaluations focused on the tool's ability to deliver adequate torque, imitate a surgical tool, and be integrated into the haptic device. Twenty-nine surgeons tested the tool in the simulator and evaluated it via a questionnaire. The device was found to deliver the 800 N·mm of torque necessary to mimic an orthopedic procedure. Surgeons found it accurately imitated surgical tool physical appearance and maneuverability, scoring them 3.9±1.0 and 3.3±1.2, respectively, on a 1-5 Likert scale. By virtue of the functionality necessary for testing and evaluation, the device could be connected to the haptic device for mechanical and electrical engagement. This device is a step forward in the field of augmentable haptic devices for surgical simulation. By changing the number of robotically-controlled degrees of freedom of a haptic device, existing devices can be tuned to meet the demands of a particular simulator, which has the potential to improve surgeon training standards.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48506893","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}
Background: The continuum over tube applied to natural orifice transluminal endoscopic surgery (NOTES) should be flexible during insertion and provide sufficient stiffness upon arrival at the lesion. In order to satisfy these two properties, a variable stiffness continuum over tube was proposed. Method: The over tube realizes stiffness variation through the heating and cooling of filling materials. Polyethylene glycol, cocoa butter and gallium metal are selected as filling materials. Several experiments were designed to test its rigid and response characteristic and suitable material was selected. The risk management test was carried out, and the frequency and risk level of the risk point was recorded. Results: According to experimental data, the polyethylene glycol and gallium shows better variable stiffness performance, with the 20 times stiffness variation range, and polyethylene glycol was selected as suitable materials for its low cost and non-toxic characteristic. The average heating time and cooling time of polyethylene glycol-filled over tube are 52.3s and 36s respectively. Moreover, three kinds of high frequency risk points including smoke, thread ejection and uneven distribution of the material were found, and corresponding design improvement and use principle are proposed. Conclusion: The proposed continuum over tube can satisfy the requirement of colorectal NOTES, and the safety of the instrument can be improved by controlling high frequency risk points with relevant methods.
{"title":"A Continuum Over Tube with Variable Stiffness for Transrectal Notes","authors":"Jinhua Li, Lan Zhang, Yuan Xing, R. Liu","doi":"10.1115/1.4054343","DOIUrl":"https://doi.org/10.1115/1.4054343","url":null,"abstract":"\u0000 Background: The continuum over tube applied to natural orifice transluminal endoscopic surgery (NOTES) should be flexible during insertion and provide sufficient stiffness upon arrival at the lesion. In order to satisfy these two properties, a variable stiffness continuum over tube was proposed.\u0000 Method: The over tube realizes stiffness variation through the heating and cooling of filling materials. Polyethylene glycol, cocoa butter and gallium metal are selected as filling materials. Several experiments were designed to test its rigid and response characteristic and suitable material was selected. The risk management test was carried out, and the frequency and risk level of the risk point was recorded.\u0000 Results: According to experimental data, the polyethylene glycol and gallium shows better variable stiffness performance, with the 20 times stiffness variation range, and polyethylene glycol was selected as suitable materials for its low cost and non-toxic characteristic. The average heating time and cooling time of polyethylene glycol-filled over tube are 52.3s and 36s respectively. Moreover, three kinds of high frequency risk points including smoke, thread ejection and uneven distribution of the material were found, and corresponding design improvement and use principle are proposed.\u0000 Conclusion: The proposed continuum over tube can satisfy the requirement of colorectal NOTES, and the safety of the instrument can be improved by controlling high frequency risk points with relevant methods.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46147740","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}
Marianna J. Coulentianos, Ilka Rodriguez-Calero, S. Daly, Jocelyn Burridge, K. Sienko
Successful medical device design entails an understanding of stakeholder-driven requirements early in the process to assure device safety and usability and support successful and positive patient experiences. Prototypes can be used during stakeholder engagement in the design front end to gather information to inform design decisions. However, an understanding of medical device industry practices of front-end stakeholder engagement with prototypes is lacking. Through interviews with medical device design practitioners, this study explored the variety of stakeholder groups engaged by design practitioners, prototype types used during stakeholder engagements, and settings in which engagements took place during front-end design activities. This study describes the 14 types of stakeholders, 14 types of prototypes, and six types of settings described by practitioners as well as patterns across engagement strategies, stakeholders, prototypes, and/or settings in front-end activities. These outcomes can contribute to broadening designers' stakeholder engagement planning and practices.
{"title":"Stakeholders, Prototypes, and Settings of Front-End Medical Device Design Activities","authors":"Marianna J. Coulentianos, Ilka Rodriguez-Calero, S. Daly, Jocelyn Burridge, K. Sienko","doi":"10.1115/1.4054207","DOIUrl":"https://doi.org/10.1115/1.4054207","url":null,"abstract":"\u0000 Successful medical device design entails an understanding of stakeholder-driven requirements early in the process to assure device safety and usability and support successful and positive patient experiences. Prototypes can be used during stakeholder engagement in the design front end to gather information to inform design decisions. However, an understanding of medical device industry practices of front-end stakeholder engagement with prototypes is lacking. Through interviews with medical device design practitioners, this study explored the variety of stakeholder groups engaged by design practitioners, prototype types used during stakeholder engagements, and settings in which engagements took place during front-end design activities. This study describes the 14 types of stakeholders, 14 types of prototypes, and six types of settings described by practitioners as well as patterns across engagement strategies, stakeholders, prototypes, and/or settings in front-end activities. These outcomes can contribute to broadening designers' stakeholder engagement planning and practices.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46521970","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}
Complications after transcatheter closure of the ventricular septal defect (VSD) is significantly associated with the mechanical behaviour of the VSD occluder. This study aims to investigate the effect of structural parameters of the VSD occluder. A mechanical model of the VSD occluder was constructed by theoretical modelling. The mechanical properties of the VSD occluders with different braiding angles (30°, 45°, 60°), materials (nitinol (NiTi), polydioxanone (PDO)) and waist-heights (3 mm, 4 mm) were analysed and validated by bench tests. For the 30°NiTi, 45°NiTi, 60°NiTi and 45°PDO occluders, the bending angles at the waist under 1 mm radial shrinkage were 112°, 121°, 155° and 155°, respectively. And the maximum principal strains at the waist were 16.62%, 8.19%, 1.20%, and 0.66%, respectively. The maximum radial deformations with 0.5 rad axial bending at the waist were 1.73, 1.44, 0.41 and 1.68 mm, respectively. When the occluders were implanted into VSD with the mean thickness of 3.5 mm, high stress appeared at the margin and the contact area, and the area with the 3-mm-occluder was much larger. In conclusion, the 60°NiTi occluder showed better ability to fit the deformation of the defect than the other NiTi occluders, and the 45°PDO occluder performed better under compression conditions but poorly under bending conditions than the 45°NiTi occluder. The choice of the appropriate waist-height is beneficial to eliminate associative complication by reducing the contact stress.
{"title":"Finite Element Analysis and Bench Testing of Ventricular Septal Defect Occluder","authors":"Yiming Li, Chengli Song, Kun Sun","doi":"10.1115/1.4054082","DOIUrl":"https://doi.org/10.1115/1.4054082","url":null,"abstract":"\u0000 Complications after transcatheter closure of the ventricular septal defect (VSD) is significantly associated with the mechanical behaviour of the VSD occluder. This study aims to investigate the effect of structural parameters of the VSD occluder. A mechanical model of the VSD occluder was constructed by theoretical modelling. The mechanical properties of the VSD occluders with different braiding angles (30°, 45°, 60°), materials (nitinol (NiTi), polydioxanone (PDO)) and waist-heights (3 mm, 4 mm) were analysed and validated by bench tests. For the 30°NiTi, 45°NiTi, 60°NiTi and 45°PDO occluders, the bending angles at the waist under 1 mm radial shrinkage were 112°, 121°, 155° and 155°, respectively. And the maximum principal strains at the waist were 16.62%, 8.19%, 1.20%, and 0.66%, respectively. The maximum radial deformations with 0.5 rad axial bending at the waist were 1.73, 1.44, 0.41 and 1.68 mm, respectively. When the occluders were implanted into VSD with the mean thickness of 3.5 mm, high stress appeared at the margin and the contact area, and the area with the 3-mm-occluder was much larger. In conclusion, the 60°NiTi occluder showed better ability to fit the deformation of the defect than the other NiTi occluders, and the 45°PDO occluder performed better under compression conditions but poorly under bending conditions than the 45°NiTi occluder. The choice of the appropriate waist-height is beneficial to eliminate associative complication by reducing the contact stress.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41782796","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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