Carpal tunnel syndrome and tendonitis are two common upper extremity cumulative trauma disorders (CTD) related to repetitive and forceful activities in industrial environments. Reducing the muscular force during activities such as the operation of a pistol grip hand tool could result in lower incidence of CTDs. The objective of this research was to reduce the muscular contribution to the grip force using an active orthosis system. A novel soft, pneumatic grasp assist device, that used a unique design of sinusoidal bellows oriented at 45 degrees, was designed to augment the users' strength during operation of pistol grip hand tool. The optimized design was fabricated using rapid prototyping. Device effectiveness was quantified by measuring muscle activity and grip force during an in vivo study of a common industrial activity. Nine subjects experienced with power tools employed by an automobile manufacturer installed 18 fasteners using a pistol grip DC tool with and without the grasp assist device. Surface electromyography (sEMG) was used to measure the activity of four muscles commonly associated with grasping. Results showed that the grasp assist significantly reduced the mean, combined, normalized muscle activity by 18% (p<0.05). Muscle activation results were contextualized using the revised strain index (RSI). The grasp assist device trial yielded a significantly lower mean RSI value than the typical trial by 13% (p<0.05). The study showed that using an active grasp assist orthosis could reduce the incidence of CTDs in able bodied industrial workers using DC hand tools.
{"title":"Design and Preliminary Validation of Grasp Assistive Device for an Industrial Environment","authors":"Daniel Loewen, N. Chandrashekar","doi":"10.1115/1.4052899","DOIUrl":"https://doi.org/10.1115/1.4052899","url":null,"abstract":"\u0000 Carpal tunnel syndrome and tendonitis are two common upper extremity cumulative trauma disorders (CTD) related to repetitive and forceful activities in industrial environments. Reducing the muscular force during activities such as the operation of a pistol grip hand tool could result in lower incidence of CTDs. The objective of this research was to reduce the muscular contribution to the grip force using an active orthosis system. A novel soft, pneumatic grasp assist device, that used a unique design of sinusoidal bellows oriented at 45 degrees, was designed to augment the users' strength during operation of pistol grip hand tool. The optimized design was fabricated using rapid prototyping. Device effectiveness was quantified by measuring muscle activity and grip force during an in vivo study of a common industrial activity. Nine subjects experienced with power tools employed by an automobile manufacturer installed 18 fasteners using a pistol grip DC tool with and without the grasp assist device. Surface electromyography (sEMG) was used to measure the activity of four muscles commonly associated with grasping. Results showed that the grasp assist significantly reduced the mean, combined, normalized muscle activity by 18% (p<0.05). Muscle activation results were contextualized using the revised strain index (RSI). The grasp assist device trial yielded a significantly lower mean RSI value than the typical trial by 13% (p<0.05). The study showed that using an active grasp assist orthosis could reduce the incidence of CTDs in able bodied industrial workers using DC hand tools.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48043745","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. Trulson, M. Küper, Artur Leis, U. Stöckle, F. Stuby, M. Hossfeld
Background: Recently presented minimally invasive endoscopic surgical techniques demonstrated the feasibility of implanting standard osteosynthesis plates for pelvic fractures. The reconstruction and internal fixation of complex acetabular fractures is still challenging. The goal of this study is to introduce a divisible implant, with a positive-locking in situ linking mechanism for plate osteosynthesis, making it possible to stabilize large and complex acetabular fractures with involvement of the quadrilateral surface. Method: Standard implants were used to recreate a base design. Using computer aided design (CAD), a three-dimensional standard implant was divided into two parts, so they could be re-allocated in situ. A critical objective was to reduce the cross-section of each part (clearance gauge). To connect the separated parts in situ, a new linking mechanism (cone in cone) was created. The new construct also features self-stabilization, self-centering, reinforced positional movement and preloading effects. Results: A linking system for plate osteosynthesis was developed entitled PEGASOS ("Percutaneous Endoscopic Guided Acetabulum-Stabilizing Osteosynthesis System"). Endoscopic implantation and in-situ-linking could be performed in a human cadaver. Therefore, we could demonstrate, that buttressing the quadrilateral surface of the acetabulum could be performed minimally invasive using a divisible suprapectineal buttress plate. Conclusion: We created a linking mechanism to couple two plates in situ. This mechanism enables an extremely strong, positive-locking connection, whereas its geometric shape allows for different relative movements during the locking procedure, with a single screw.
{"title":"PEGASOS - A New Linking Mechanism for Modular Osteosynthesis Plates in Minimally Invasive Acetabular Surgery","authors":"A. Trulson, M. Küper, Artur Leis, U. Stöckle, F. Stuby, M. Hossfeld","doi":"10.1115/1.4052786","DOIUrl":"https://doi.org/10.1115/1.4052786","url":null,"abstract":"\u0000 Background: Recently presented minimally invasive endoscopic surgical techniques demonstrated the feasibility of implanting standard osteosynthesis plates for pelvic fractures. The reconstruction and internal fixation of complex acetabular fractures is still challenging. The goal of this study is to introduce a divisible implant, with a positive-locking in situ linking mechanism for plate osteosynthesis, making it possible to stabilize large and complex acetabular fractures with involvement of the quadrilateral surface.\u0000 Method: Standard implants were used to recreate a base design. Using computer aided design (CAD), a three-dimensional standard implant was divided into two parts, so they could be re-allocated in situ. A critical objective was to reduce the cross-section of each part (clearance gauge). To connect the separated parts in situ, a new linking mechanism (cone in cone) was created. The new construct also features self-stabilization, self-centering, reinforced positional movement and preloading effects.\u0000 Results: A linking system for plate osteosynthesis was developed entitled PEGASOS (\"Percutaneous Endoscopic Guided Acetabulum-Stabilizing Osteosynthesis System\"). Endoscopic implantation and in-situ-linking could be performed in a human cadaver. Therefore, we could demonstrate, that buttressing the quadrilateral surface of the acetabulum could be performed minimally invasive using a divisible suprapectineal buttress plate.\u0000 Conclusion: We created a linking mechanism to couple two plates in situ. This mechanism enables an extremely strong, positive-locking connection, whereas its geometric shape allows for different relative movements during the locking procedure, with a single screw.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44109426","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}
M. A. Gull, S. Bai, J. Blicher, Tobias Glaston Staermose
Finger extensor muscle weakness and flexor hypertonia are the most commonly reported issues among patients suffering from amyotrophic lateral sclerosis (ALS). Moreover, the relative hyperflexion of the wrist and fingers has limited their ability to voluntarily open the hand and interact with the external environment. In this work, a hybrid hand exoskeleton is developed to prevent the relative hyperflexion of the fingers and wrist and facilitate the users in their functional hand opening by compensating the flexor hypertonia. This exoskeleton, combining a passive device with the soft extra muscle (SEM) glove, assists users in normal hand opening/closing required for some basic activities of daily living. The paper presents kinematic and static models of passive hand exoskeleton design. Moreover, the proposed design is tested and evaluated by comparing the volunteer hand opening with the exoskeleton assistance using the flex sensors attached on the dorsal side of the middle finger, ring finger, and thumb with both healthy subjects and patients. The results show the effectiveness of using the hybrid exoskeleton in improving anatomical hand opening/closing capabilities.
{"title":"Design and Performance Evaluation of a Hybrid Hand Exoskeleton for Hand Opening/Closing","authors":"M. A. Gull, S. Bai, J. Blicher, Tobias Glaston Staermose","doi":"10.1115/1.4052448","DOIUrl":"https://doi.org/10.1115/1.4052448","url":null,"abstract":"\u0000 Finger extensor muscle weakness and flexor hypertonia are the most commonly reported issues among patients suffering from amyotrophic lateral sclerosis (ALS). Moreover, the relative hyperflexion of the wrist and fingers has limited their ability to voluntarily open the hand and interact with the external environment. In this work, a hybrid hand exoskeleton is developed to prevent the relative hyperflexion of the fingers and wrist and facilitate the users in their functional hand opening by compensating the flexor hypertonia. This exoskeleton, combining a passive device with the soft extra muscle (SEM) glove, assists users in normal hand opening/closing required for some basic activities of daily living. The paper presents kinematic and static models of passive hand exoskeleton design. Moreover, the proposed design is tested and evaluated by comparing the volunteer hand opening with the exoskeleton assistance using the flex sensors attached on the dorsal side of the middle finger, ring finger, and thumb with both healthy subjects and patients. The results show the effectiveness of using the hybrid exoskeleton in improving anatomical hand opening/closing capabilities.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46779063","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 advantage of handheld type surgical microscope is that the size of the probe is small and light, and the working distance(o to 30 cm) and field of view (306°) can be adjusted. Also, a short working distance will minimize the loss of light source energy. However, the currently developed handheld type surgical microscope is still large, heavy, and uses relatively high energy (600 mW). Also, it is not suitable for portable use. To address the aforementioned problems, this study aimed to develop a pen-type surgical fluorescence microscope that is compact, portable, and has an adjustable beam angle and working distance. The pen-type probe consists of a laser diode, CMOS camera, light source brightness control device, filter, and power switch. The IR-cut filter inside the CMOS camera was removed to facilitate transmission of the fluorescence emission wavelength. In addition, a long-pass filter was attached to the camera so that the external light source was blocked and only the fluorescence emission wavelength was allowed to pass through. The pen-type probe was manufactured using 3D printing, and the captured image was designed to be observed through an external monitor. The performance of the pen-type probe was tested through a large animal experiment. Indocyanine green (2.5mg/kg) was injected into a pig's vein. Fluorescence emission of 805-830 nm was achieved by irradiating an external light source (785 nm and 4 mW/cm2), and liver-uptake occurred after 2.4 minutes.
{"title":"Design of a Surgical Pen-Type Probe for Real-Time Indocyanine Green Fluorescence Emission Diagnosis","authors":"K. Yoon, Kwang Gi Kim, Seung Hoon Lee","doi":"10.1115/1.4052587","DOIUrl":"https://doi.org/10.1115/1.4052587","url":null,"abstract":"\u0000 The advantage of handheld type surgical microscope is that the size of the probe is small and light, and the working distance(o to 30 cm) and field of view (306°) can be adjusted. Also, a short working distance will minimize the loss of light source energy. However, the currently developed handheld type surgical microscope is still large, heavy, and uses relatively high energy (600 mW). Also, it is not suitable for portable use. To address the aforementioned problems, this study aimed to develop a pen-type surgical fluorescence microscope that is compact, portable, and has an adjustable beam angle and working distance.\u0000 The pen-type probe consists of a laser diode, CMOS camera, light source brightness control device, filter, and power switch. The IR-cut filter inside the CMOS camera was removed to facilitate transmission of the fluorescence emission wavelength. In addition, a long-pass filter was attached to the camera so that the external light source was blocked and only the fluorescence emission wavelength was allowed to pass through. The pen-type probe was manufactured using 3D printing, and the captured image was designed to be observed through an external monitor.\u0000 The performance of the pen-type probe was tested through a large animal experiment. Indocyanine green (2.5mg/kg) was injected into a pig's vein. Fluorescence emission of 805-830 nm was achieved by irradiating an external light source (785 nm and 4 mW/cm2), and liver-uptake occurred after 2.4 minutes.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41580801","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}
O. Pinto, Isabel Flesch Laforce, Dimitra Vlaskou Badra, C. Roesler
This paper proposes a new testing method based on the toggle effect under transverse loads (cranial-caudal) to investigate the loosening potential of pedicular screw designs. A three-step in vitro testing procedure was developed to mimic the loosening mechanism of pedicular screws. Firstly, the pedicular screw of a certain design is inserted into a bone substitute model specifically designed for the test. Secondly, a controlled cyclic cranial-caudal loading is applied transversally to the longitudinal axis of the screw for three ascendent load levels (staircase) by a pre-determined number of load cycles. Lastly, each pedicular screw is adjusted and submitted to axial pull-out quasi-static testing. The results are used to calculate a loosening index that, together with statistical analysis, indicates the potential for loosening of the specific design evaluated. The proposed testing method effectively provides a simulated environment to evaluate the loosening potential of pedicular screw designs. The proposed loosening index calculation may be used to compare different pedicular screw designs. The proposed methodology was verified as a valuable tool to investigate the influence of the cranial-caudal loads on pedicular screw behavior. It offers a new alternative for use in pre-clinical studies on the loosening potential of pedicular screw designs.
{"title":"A New Test Method for in vitro Evaluation of Pedicle Screw Loosening Potential","authors":"O. Pinto, Isabel Flesch Laforce, Dimitra Vlaskou Badra, C. Roesler","doi":"10.1115/1.4052517","DOIUrl":"https://doi.org/10.1115/1.4052517","url":null,"abstract":"\u0000 This paper proposes a new testing method based on the toggle effect under transverse loads (cranial-caudal) to investigate the loosening potential of pedicular screw designs. A three-step in vitro testing procedure was developed to mimic the loosening mechanism of pedicular screws. Firstly, the pedicular screw of a certain design is inserted into a bone substitute model specifically designed for the test. Secondly, a controlled cyclic cranial-caudal loading is applied transversally to the longitudinal axis of the screw for three ascendent load levels (staircase) by a pre-determined number of load cycles. Lastly, each pedicular screw is adjusted and submitted to axial pull-out quasi-static testing. The results are used to calculate a loosening index that, together with statistical analysis, indicates the potential for loosening of the specific design evaluated. The proposed testing method effectively provides a simulated environment to evaluate the loosening potential of pedicular screw designs. The proposed loosening index calculation may be used to compare different pedicular screw designs. The proposed methodology was verified as a valuable tool to investigate the influence of the cranial-caudal loads on pedicular screw behavior. It offers a new alternative for use in pre-clinical studies on the loosening potential of pedicular screw designs.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47979026","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}
David M. Ziemnicki, Joshua M. Caputo, Kirsty A. McDonald, K. Zelik
In individuals with transtibial limb loss, a contributing factor to mobility-related challenges is the disruption of biological calf muscle function due to transection of the soleus and gastrocnemius. Powered prosthetic ankles can restore primary function of the mono-articular soleus muscle, which contributes to ankle plantarflexion. In effect, a powered ankle acts like an artificial soleus. However, the biarticular gastrocnemius connection that simultaneously contributes to ankle plantarflexion and knee flexion torques remains missing, and there are currently no commercially-available prosthetic ankles that incorporate an artificial gastrocnemius. The goal of this work is to describe the design of a novel emulator capable of independently controlling artificial soleus and gastrocnemius behaviors for transtibial prosthesis users during walking. To evaluate the emulator's efficacy in controlling the artificial gastrocnemius behaviors, a case series walking study was conducted with 4 transtibial prosthesis users. Data from this case series showed that the emulator exhibits low resistances to the user's leg swing, low hysteresis during passive spring emulation, and accurate force tracking for a range of artificial soleus and gastrocnemius behaviors. The emulator presented in this paper is versatile and can facilitate experiments studying the effects of various artificial soleus and gastrocnemius dynamics on gait or other movement tasks. Using this system, it is possible to address existing knowledge gaps and explore a wide range of artificial soleus and gastrocnemius behaviors during gait and potentially other activities of daily living.
{"title":"Development and Evaluation of a Prosthetic Ankle Emulator with an Artificial Soleus and Gastrocnemius","authors":"David M. Ziemnicki, Joshua M. Caputo, Kirsty A. McDonald, K. Zelik","doi":"10.1115/1.4052518","DOIUrl":"https://doi.org/10.1115/1.4052518","url":null,"abstract":"\u0000 In individuals with transtibial limb loss, a contributing factor to mobility-related challenges is the disruption of biological calf muscle function due to transection of the soleus and gastrocnemius. Powered prosthetic ankles can restore primary function of the mono-articular soleus muscle, which contributes to ankle plantarflexion. In effect, a powered ankle acts like an artificial soleus. However, the biarticular gastrocnemius connection that simultaneously contributes to ankle plantarflexion and knee flexion torques remains missing, and there are currently no commercially-available prosthetic ankles that incorporate an artificial gastrocnemius. The goal of this work is to describe the design of a novel emulator capable of independently controlling artificial soleus and gastrocnemius behaviors for transtibial prosthesis users during walking. To evaluate the emulator's efficacy in controlling the artificial gastrocnemius behaviors, a case series walking study was conducted with 4 transtibial prosthesis users. Data from this case series showed that the emulator exhibits low resistances to the user's leg swing, low hysteresis during passive spring emulation, and accurate force tracking for a range of artificial soleus and gastrocnemius behaviors. The emulator presented in this paper is versatile and can facilitate experiments studying the effects of various artificial soleus and gastrocnemius dynamics on gait or other movement tasks. Using this system, it is possible to address existing knowledge gaps and explore a wide range of artificial soleus and gastrocnemius behaviors during gait and potentially other activities of daily living.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45202399","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}
To improve the prevalence of screening for gastric cancer in low-income areas, a low-cost endoscope based on a novel wire-driven rotary valve and water-jet mechanism is proposed. The primary component of this endoscope is a rotary valve whose core is driven by a stepper motor through a flexible wire, which controls the direction of the water jet. This enables it to reach any point in the workspace by controlling the valve core angle and water-jet intensity. The envelope surface of the endoscope tip trajectory is likely a hemisphere. The horizontal diameter of the working space projection is approximately 350 mm, which is sufficient to observe most parts of the greater curvature of the stomach. The image-acquisition performance of the designed endoscope was satisfactory in a phantom experiment. The introduction of the novel rotary valve greatly simplifies the structure and reduces the cost of the proposed endoscope. With low cost and high portability, this endoscope provides a good alternative for early gastric cancer screening in low- and middle-income areas.
{"title":"Design of Low-Cost Endoscope Based on Novel Wire-Driven Rotary Valve and Water-Jet Mechanism","authors":"Guoyu Ma, Siyang Zuo, Jianbin Liu","doi":"10.1115/1.4052304","DOIUrl":"https://doi.org/10.1115/1.4052304","url":null,"abstract":"\u0000 To improve the prevalence of screening for gastric cancer in low-income areas, a low-cost endoscope based on a novel wire-driven rotary valve and water-jet mechanism is proposed. The primary component of this endoscope is a rotary valve whose core is driven by a stepper motor through a flexible wire, which controls the direction of the water jet. This enables it to reach any point in the workspace by controlling the valve core angle and water-jet intensity. The envelope surface of the endoscope tip trajectory is likely a hemisphere. The horizontal diameter of the working space projection is approximately 350 mm, which is sufficient to observe most parts of the greater curvature of the stomach. The image-acquisition performance of the designed endoscope was satisfactory in a phantom experiment. The introduction of the novel rotary valve greatly simplifies the structure and reduces the cost of the proposed endoscope. With low cost and high portability, this endoscope provides a good alternative for early gastric cancer screening in low- and middle-income areas.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46405559","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}
J. Reeves, T. Vanasse, C. Roche, K. Faber, G. Langohr
Objective: During shoulder arthroplasty, surgeons must select the optimal implant for each patient. The metaphyseal bone properties affect this decision; however, the typical resection “thumb test” lacks objectivity. This investigation's purposes were to determine the correlation strength between the indentation depth of a handheld mechanism and the density, compressive strength, and modulus of a bone surrogate; as well as to assess how changing the indenter tip shape and impact energy may affect the correlation strengths. Methods: A spring-loaded indenter was developed. Four tip shapes (needle, tapered, flat, and radiused cylinders) and four spring energies (0.13 J–0.76J) were assessed by indenting five cellular foam bone surrogates of varying density, every five times. After each indentation, the indentation depth was measured with a separate probe and correlated with manufacturer specifications of the apparent density, compressive strength, and modulus. Results: indentation depth plateaued as the bone surrogate's material properties increased, particularly for indentation tips with larger footprints and the 0.13 J spring. All tip shapes produced strong (R2≥0.7) power-law relationships between the indentation depth metric and the bone surrogate's material properties (density: 0.70 ≤ R2 ≤ 0.95, strength: 0.75 ≤ R2 ≤ 0.97, modulus: 0.70 ≤ R2 ≤ 0.93); though the use of the needle tip yielded the widest indentation depth scale. Interpretation: these strong correlations suggest that a handheld indenter may provide objective intra-operative evidence of cancellous material properties. Further investigations are warranted to study indenter tip shape and spring energy in human tissue; though the needle tip with spring energy between 0.30 J and 0.76 J seems the most promising.
{"title":"Initial Assessments of a Handheld Indentation Probe's Correlation With Cancellous Bone Density, Stiffness, and Strength: An Objective Alternative to “Thumb Testing”","authors":"J. Reeves, T. Vanasse, C. Roche, K. Faber, G. Langohr","doi":"10.1115/1.4052305","DOIUrl":"https://doi.org/10.1115/1.4052305","url":null,"abstract":"\u0000 Objective: During shoulder arthroplasty, surgeons must select the optimal implant for each patient. The metaphyseal bone properties affect this decision; however, the typical resection “thumb test” lacks objectivity. This investigation's purposes were to determine the correlation strength between the indentation depth of a handheld mechanism and the density, compressive strength, and modulus of a bone surrogate; as well as to assess how changing the indenter tip shape and impact energy may affect the correlation strengths. Methods: A spring-loaded indenter was developed. Four tip shapes (needle, tapered, flat, and radiused cylinders) and four spring energies (0.13 J–0.76J) were assessed by indenting five cellular foam bone surrogates of varying density, every five times. After each indentation, the indentation depth was measured with a separate probe and correlated with manufacturer specifications of the apparent density, compressive strength, and modulus. Results: indentation depth plateaued as the bone surrogate's material properties increased, particularly for indentation tips with larger footprints and the 0.13 J spring. All tip shapes produced strong (R2≥0.7) power-law relationships between the indentation depth metric and the bone surrogate's material properties (density: 0.70 ≤ R2 ≤ 0.95, strength: 0.75 ≤ R2 ≤ 0.97, modulus: 0.70 ≤ R2 ≤ 0.93); though the use of the needle tip yielded the widest indentation depth scale. Interpretation: these strong correlations suggest that a handheld indenter may provide objective intra-operative evidence of cancellous material properties. Further investigations are warranted to study indenter tip shape and spring energy in human tissue; though the needle tip with spring energy between 0.30 J and 0.76 J seems the most promising.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42690291","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}
Liaoyuan Ai, Chengli Song, L. Mao, Shuchen Ge, Zhen Pan
Endoscopic closure has become the first choice for closing iatrogenic perforations. Previously, we reported a self-developed endoscopic multifiring clip applicator (EMFCA) system. In this paper, a new EMFCA system for endoscopic closure of large perforations with a redesigned clip, the less traumatic grasper, and a highly efficient driving system was presented, and its efficacy was evaluated. The behaviors of the new clip and grasper were verified through finite element analysis (FEA). The capability of pushing transmission for the EMFCA system was identified by the proposed model and the validation experiment. Ex-vivo studies were conducted on porcine stomachs to compare the outcomes of the closures. The FEA results showed that the deformation of the clip was safe and smoother, with a maximum stress of 640.0 MPa. The less traumatic grasper could increase the grasping force and avoid trauma by exerting uniform stress along the axis. The capability of pushing transmission was enhanced by the double-nested tendon-sheath actuation system with an efficiency of 0.45–0.48. The mechanical strength, the leakage pressure, and the operating time for the closures with the new EMFCA system and the previous EMFCA system were 6.1 N ± 0.8 N, 37.1 mmHg ± 6.8 mmHg, 7.3 min ± 0.4 min and 5.1 N ± 1.0 N, 27.4 mmHg ± 6.4 mmHg, 11.4 min ±0.8 min, respectively. The new EMFCA system can realize a superior, reliable, and high-efficiency endoscopic closure of large perforations.
{"title":"Design Optimization of a Novel Multifiring Clip Applicator System for Endoscopic Closure of Large Perforations","authors":"Liaoyuan Ai, Chengli Song, L. Mao, Shuchen Ge, Zhen Pan","doi":"10.1115/1.4051191","DOIUrl":"https://doi.org/10.1115/1.4051191","url":null,"abstract":"\u0000 Endoscopic closure has become the first choice for closing iatrogenic perforations. Previously, we reported a self-developed endoscopic multifiring clip applicator (EMFCA) system. In this paper, a new EMFCA system for endoscopic closure of large perforations with a redesigned clip, the less traumatic grasper, and a highly efficient driving system was presented, and its efficacy was evaluated. The behaviors of the new clip and grasper were verified through finite element analysis (FEA). The capability of pushing transmission for the EMFCA system was identified by the proposed model and the validation experiment. Ex-vivo studies were conducted on porcine stomachs to compare the outcomes of the closures. The FEA results showed that the deformation of the clip was safe and smoother, with a maximum stress of 640.0 MPa. The less traumatic grasper could increase the grasping force and avoid trauma by exerting uniform stress along the axis. The capability of pushing transmission was enhanced by the double-nested tendon-sheath actuation system with an efficiency of 0.45–0.48. The mechanical strength, the leakage pressure, and the operating time for the closures with the new EMFCA system and the previous EMFCA system were 6.1 N ± 0.8 N, 37.1 mmHg ± 6.8 mmHg, 7.3 min ± 0.4 min and 5.1 N ± 1.0 N, 27.4 mmHg ± 6.4 mmHg, 11.4 min ±0.8 min, respectively. The new EMFCA system can realize a superior, reliable, and high-efficiency endoscopic closure of large perforations.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":"71 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83965230","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}
Omar Faruk Emon, A. Russell, Gopal Nadkarni, Jae-Won Choi
Neuropathy is a nerve-damaging disease that causes those affected to lose feeling in their otherwise functional limbs. It can cause permanent numbing to the peripheral limb of a patient such as a hand or foot. In this report, we present a real-time visualization aid for grasp realization that can be used by patients experiencing numbness of the limb. This wearable electronic device was developed on an open-source microcontroller-based platform. This is a very simple and inexpensive solution. It is referred to as the NeuroGlove, and it provides patients with a visual light scale to allow them to understand the strength of the grasp that they have on any object. A soft tactile sensor was additively manufactured by utilizing a multimaterial direct-print system. The sensor consists of an ionic liquid (IL)-based pressure-sensitive membrane, stretchable electrodes, and insulation membranes. The printed flexible polymeric sensor was evaluated under varying forces. Next, the fabricated sensor was integrated with a microcontroller board where it was programmed to respond in a light scale according to the applied force on the sensor. Finally, the sensor-microcontroller system was installed on a glove to demonstrate a wearable visual aid for neuropathy patients. Additive manufacturing offers the ability for customization in a design, material, and geometry that could potentially lead to printing sensors on prosthetic or robotic hands.
{"title":"A Low-Cost Visual Grasp Aid for Neuropathy Patients Using Flexible Three-Dimensional Printed Tactile Sensors","authors":"Omar Faruk Emon, A. Russell, Gopal Nadkarni, Jae-Won Choi","doi":"10.1115/1.4051247","DOIUrl":"https://doi.org/10.1115/1.4051247","url":null,"abstract":"\u0000 Neuropathy is a nerve-damaging disease that causes those affected to lose feeling in their otherwise functional limbs. It can cause permanent numbing to the peripheral limb of a patient such as a hand or foot. In this report, we present a real-time visualization aid for grasp realization that can be used by patients experiencing numbness of the limb. This wearable electronic device was developed on an open-source microcontroller-based platform. This is a very simple and inexpensive solution. It is referred to as the NeuroGlove, and it provides patients with a visual light scale to allow them to understand the strength of the grasp that they have on any object. A soft tactile sensor was additively manufactured by utilizing a multimaterial direct-print system. The sensor consists of an ionic liquid (IL)-based pressure-sensitive membrane, stretchable electrodes, and insulation membranes. The printed flexible polymeric sensor was evaluated under varying forces. Next, the fabricated sensor was integrated with a microcontroller board where it was programmed to respond in a light scale according to the applied force on the sensor. Finally, the sensor-microcontroller system was installed on a glove to demonstrate a wearable visual aid for neuropathy patients. Additive manufacturing offers the ability for customization in a design, material, and geometry that could potentially lead to printing sensors on prosthetic or robotic hands.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":"234 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84739171","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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