Pub Date : 2023-06-01Epub Date: 2023-04-17DOI: 10.1115/1.4056866
Aman Ladak, Roger J Hajjar, Srinivas Murali, Jeremy J Michalek, Cameron N Riviere
HeartPrinter is a novel under-constrained 3-cable parallel wire robot designed for minimally invasive epicardial interventions. The robot adheres to the beating heart using vacuum suction at its anchor points, with a central injector head that operates within the triangular workspace formed by the anchors, and is actuated by cables for multipoint direct gene therapy injections. Minimizing cable tensions can reduce forces on the heart at the anchor points while supporting rapid delivery of accurate injections and minimizing procedure time, risk of damage to the robot, and strain to the heart. However, cable tensions must be sufficient to hold the injector head's position as the heart moves and to prevent excessive cable slack. We pose a linear optimization problem to minimize the sum of cable tension magnitudes for HeartPrinter while ensuring the injector head is held in static equilibrium and the tensions are constrained within a feasible range. We use Karush-Kuhn-Tucker optimality conditions to derive conditional algebraic expressions for optimal cable tensions as a function of injector head position and workspace geometry, and we identify regions of injector head positions where particular combinations of cable tensions are optimally at minimum allowable tensions. The approach can rapidly solve for the minimum set of cable tensions for any robot workspace geometry and injector head position and determine whether an injection site is attainable.
{"title":"Cable Tension Optimization for an Epicardial Parallel Wire Robot.","authors":"Aman Ladak, Roger J Hajjar, Srinivas Murali, Jeremy J Michalek, Cameron N Riviere","doi":"10.1115/1.4056866","DOIUrl":"10.1115/1.4056866","url":null,"abstract":"<p><p>HeartPrinter is a novel under-constrained 3-cable parallel wire robot designed for minimally invasive epicardial interventions. The robot adheres to the beating heart using vacuum suction at its anchor points, with a central injector head that operates within the triangular workspace formed by the anchors, and is actuated by cables for multipoint direct gene therapy injections. Minimizing cable tensions can reduce forces on the heart at the anchor points while supporting rapid delivery of accurate injections and minimizing procedure time, risk of damage to the robot, and strain to the heart. However, cable tensions must be sufficient to hold the injector head's position as the heart moves and to prevent excessive cable slack. We pose a linear optimization problem to minimize the sum of cable tension magnitudes for HeartPrinter while ensuring the injector head is held in static equilibrium and the tensions are constrained within a feasible range. We use Karush-Kuhn-Tucker optimality conditions to derive conditional algebraic expressions for optimal cable tensions as a function of injector head position and workspace geometry, and we identify regions of injector head positions where particular combinations of cable tensions are optimally at minimum allowable tensions. The approach can rapidly solve for the minimum set of cable tensions for any robot workspace geometry and injector head position and determine whether an injection site is attainable.</p>","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10158971/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9423533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-01Epub Date: 2023-04-17DOI: 10.1115/1.4056864
Vishwanath D Ketkar, Eric T Wolbrecht, Joel C Perry, Andria Farrens
This paper presents the kinematic design and development of a two degree-of-freedom (2DOF) spherical 5-bar thumb exoskeleton to augment the finger individuating grasp exercise robot (FINGER) rehabilitation robot, which assists the index and middle fingers individually in naturalistic grasping. The thumb module expands the capabilities of FINGER, allowing for broader proprioceptive training and assessment of hand function. The design process started by digitizing thumb-grasping motions to the index and the middle fingers separately, recorded from multiple healthy subjects utilizing a motion capture system. Fitting spheres to trajectory data of each subject allowed normalization of all subjects' data to a common center and radius. A two-revolute joint serial-chain mechanism was synthesized (intermediate optimization step) to reach the normalized trajectories. Next, the two resulting grasping trajectories were spatially sampled as targets for the 2DOF spherical 5-bar synthesis. Optimization of the spherical 5-bar included symmetry constraints and cost-function penalties for poor manipulability. The resulting exoskeleton assists both flexion/extension and abduction/adduction of the thumb enabling a wide range of motions. Consistent with FINGER, the parallel structure of the spherical 5-bar places the actuators at the base of the module, allowing for desirable characteristics, including high backdrivability, high controllable bandwidth, and low mechanical impedance. The mechanical design was developed from the kinematic solution, including an adjustable thumb cuff to accommodate different hand sizes. Fit and function of the device were tested on multiple subjects, including survivors of stroke. A proportional-derivative force controller with gravity and friction compensation was implemented to reduce resistance to motion during subject testing.
{"title":"Design and Development of a Spherical 5-Bar Thumb Exoskeleton Mechanism for Poststroke Rehabilitation.","authors":"Vishwanath D Ketkar, Eric T Wolbrecht, Joel C Perry, Andria Farrens","doi":"10.1115/1.4056864","DOIUrl":"10.1115/1.4056864","url":null,"abstract":"<p><p>This paper presents the kinematic design and development of a two degree-of-freedom (2DOF) spherical 5-bar thumb exoskeleton to augment the finger individuating grasp exercise robot (FINGER) rehabilitation robot, which assists the index and middle fingers individually in naturalistic grasping. The thumb module expands the capabilities of FINGER, allowing for broader proprioceptive training and assessment of hand function. The design process started by digitizing thumb-grasping motions to the index and the middle fingers separately, recorded from multiple healthy subjects utilizing a motion capture system. Fitting spheres to trajectory data of each subject allowed normalization of all subjects' data to a common center and radius. A two-revolute joint serial-chain mechanism was synthesized (intermediate optimization step) to reach the normalized trajectories. Next, the two resulting grasping trajectories were spatially sampled as targets for the 2DOF spherical 5-bar synthesis. Optimization of the spherical 5-bar included symmetry constraints and cost-function penalties for poor manipulability. The resulting exoskeleton assists both flexion/extension and abduction/adduction of the thumb enabling a wide range of motions. Consistent with FINGER, the parallel structure of the spherical 5-bar places the actuators at the base of the module, allowing for desirable characteristics, including high backdrivability, high controllable bandwidth, and low mechanical impedance. The mechanical design was developed from the kinematic solution, including an adjustable thumb cuff to accommodate different hand sizes. Fit and function of the device were tested on multiple subjects, including survivors of stroke. A proportional-derivative force controller with gravity and friction compensation was implemented to reduce resistance to motion during subject testing.</p>","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10158975/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9430643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jack Mankowsky, Connor Quigley, Scott Clark, A. Habib
Traditional cell culturing methods are limited in their ability to supply growth medium to cells within scaffolds. To address this, we developed a custom perfusion bioreactor that allows for dynamic medium supply to encapsulated or seeded cells. Our custom-designed bioreactor improves the in vivo stimuli and conditions, which may enhance cell viability and proliferation performance. Some of the efforts include using dual medium tanks to replace the medium without stopping perfusion and a newly designed perfusion chamber that can accommodate an array of cassettes allowing for a wide assortment of scaffold shapes and sizes. In this paper, we explored the response of fluid flow to certain types of scaffold pore geometries and porosities using simulation and experimental approaches. Various pore geometries were considered, such as uniform triangular, square, diamond, circular, and honeycomb having uniform and variable sizes. Finally, bone tissue architecture was mimicked and simulated to identify the impact of fluid flow. Based on the results, optimum pore geometry for scaffolds were determined. We explored real-time fluid flow response on scaffolds fabricated with 8% Alginate, 4% Alginate-4% Carboxymethyl Cellulose (CMC), and 2% Alginate-6% CMC incubated, allowing a constant fluid flow for various periods such as 1, 2, 4, and 8 h. The change of fabricated scaffolds was determined in terms of swelling rate, i.e., change of filament width and material diffusion, i.e., comparison of dry material weight before and after incubation. This comparative study can assist in application-based materials selection suitable for incubating in a perfusion bioreactor.
{"title":"Identifying Suitable Three-Dimensional Bio-Printed Scaffold Architectures to Incubate in a Perfusion Bioreactor: Simulation and Experimental Approaches","authors":"Jack Mankowsky, Connor Quigley, Scott Clark, A. Habib","doi":"10.1115/1.4062492","DOIUrl":"https://doi.org/10.1115/1.4062492","url":null,"abstract":"\u0000 Traditional cell culturing methods are limited in their ability to supply growth medium to cells within scaffolds. To address this, we developed a custom perfusion bioreactor that allows for dynamic medium supply to encapsulated or seeded cells. Our custom-designed bioreactor improves the in vivo stimuli and conditions, which may enhance cell viability and proliferation performance. Some of the efforts include using dual medium tanks to replace the medium without stopping perfusion and a newly designed perfusion chamber that can accommodate an array of cassettes allowing for a wide assortment of scaffold shapes and sizes. In this paper, we explored the response of fluid flow to certain types of scaffold pore geometries and porosities using simulation and experimental approaches. Various pore geometries were considered, such as uniform triangular, square, diamond, circular, and honeycomb having uniform and variable sizes. Finally, bone tissue architecture was mimicked and simulated to identify the impact of fluid flow. Based on the results, optimum pore geometry for scaffolds were determined. We explored real-time fluid flow response on scaffolds fabricated with 8% Alginate, 4% Alginate-4% Carboxymethyl Cellulose (CMC), and 2% Alginate-6% CMC incubated, allowing a constant fluid flow for various periods such as 1, 2, 4, and 8 h. The change of fabricated scaffolds was determined in terms of swelling rate, i.e., change of filament width and material diffusion, i.e., comparison of dry material weight before and after incubation. This comparative study can assist in application-based materials selection suitable for incubating in a perfusion bioreactor.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43930728","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. Afsar, Md Ashiquzzaman, D. Martelli, Xiangrong Shen
Mobility impairment is a major problem that affects the quality of life of numerous older adults. With impaired mobility, such individuals usually have significant difficulty in standing up from a seated position, and thus often suffer from the lack of physical activities in their daily life. To address this problem, the authors present a new assistive device, namely Semi-Wearable Sit-to-Stand Assist Generation-2 (SW-SiStA2), in this paper. Similar to the original (first generation) SW-SiStA, this novel semi-wearable device can be easily attached to the user to provide sit-to-stand assistance, and can also be easily detached after reaching the standing posture to facilitate the subsequent ambulation. The new SW-SiStA2 is powered with a remote-release gas spring, which serves the dual purpose of actuation and energy storage (i.e., storing the energy accumulated during compression and powering the sit-to-stand assistance through extension). The remote release feature enables a user to easily control the SW-SiStA2 assistance through the locking and unlocking of the gas spring. The SW-SiStA2 was experimentally tested with human participants. Under the device's assistance, the participants were able to stand up much more easily, with significant reduction (up to 28% compared with the unassisted condition) of the muscle efforts in the process.
{"title":"SW-SiStA2: A New-Generation Semi-Wearable Device for Sit-to-Stand Assistance","authors":"M. Afsar, Md Ashiquzzaman, D. Martelli, Xiangrong Shen","doi":"10.1115/1.4062337","DOIUrl":"https://doi.org/10.1115/1.4062337","url":null,"abstract":"\u0000 Mobility impairment is a major problem that affects the quality of life of numerous older adults. With impaired mobility, such individuals usually have significant difficulty in standing up from a seated position, and thus often suffer from the lack of physical activities in their daily life. To address this problem, the authors present a new assistive device, namely Semi-Wearable Sit-to-Stand Assist Generation-2 (SW-SiStA2), in this paper. Similar to the original (first generation) SW-SiStA, this novel semi-wearable device can be easily attached to the user to provide sit-to-stand assistance, and can also be easily detached after reaching the standing posture to facilitate the subsequent ambulation. The new SW-SiStA2 is powered with a remote-release gas spring, which serves the dual purpose of actuation and energy storage (i.e., storing the energy accumulated during compression and powering the sit-to-stand assistance through extension). The remote release feature enables a user to easily control the SW-SiStA2 assistance through the locking and unlocking of the gas spring. The SW-SiStA2 was experimentally tested with human participants. Under the device's assistance, the participants were able to stand up much more easily, with significant reduction (up to 28% compared with the unassisted condition) of the muscle efforts in the process.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41874930","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}
Jingzhen Guo, L. Mao, Chengli Song, Yiling Shi, Yongji Tian
Restenosis after stent implantation is a major limitation of revascularization technique. Retrieving the stent safely and smoothly after the vascular remodeling is completed shows important clinical significance. In this paper, a novel retrievable peripheral vascular stent and its modified retrieval platform were developed and the finite element analysis (FEA) model was established to study the retrieval process of the stent. Meanwhile, the safety and feasibility of the retrievable stent were assessed through in vivo experiments. The maximum strain of the stent is 6.87% during the whole retrieval process, which is less than the ultimate elastic strain of nitinol alloy. The simulation results indicate that the stent is not damaged or stuck during the whole retrieval process. Finally, the stents were implanted into Bama miniature pigs to assess the retrieval process, and the results suggest that the stents can be retrieved successfully within a short period of time after implantation, and minor local mechanical injury can be found in the intimal layer of the blood vessel due to the expansion and contraction of the stent. Studies presented in this work illustrate the feasibility of a novel retrievable peripheral vascular stent, providing an additional avenue to avoid in-stent restenosis.
{"title":"Design and Experiment Research of a Novel Retrievable Peripheral Vascular Stent","authors":"Jingzhen Guo, L. Mao, Chengli Song, Yiling Shi, Yongji Tian","doi":"10.1115/1.4062338","DOIUrl":"https://doi.org/10.1115/1.4062338","url":null,"abstract":"\u0000 Restenosis after stent implantation is a major limitation of revascularization technique. Retrieving the stent safely and smoothly after the vascular remodeling is completed shows important clinical significance. In this paper, a novel retrievable peripheral vascular stent and its modified retrieval platform were developed and the finite element analysis (FEA) model was established to study the retrieval process of the stent. Meanwhile, the safety and feasibility of the retrievable stent were assessed through in vivo experiments. The maximum strain of the stent is 6.87% during the whole retrieval process, which is less than the ultimate elastic strain of nitinol alloy. The simulation results indicate that the stent is not damaged or stuck during the whole retrieval process. Finally, the stents were implanted into Bama miniature pigs to assess the retrieval process, and the results suggest that the stents can be retrieved successfully within a short period of time after implantation, and minor local mechanical injury can be found in the intimal layer of the blood vessel due to the expansion and contraction of the stent. Studies presented in this work illustrate the feasibility of a novel retrievable peripheral vascular stent, providing an additional avenue to avoid in-stent restenosis.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49464630","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}
Samson Galvin, R. Yanalitis, Eric Leon, J. Winder, R. Haluck, P. von Lockette, J. Moore
Laparoscopic surgery is a common minimally invasive surgery that uses specialized tools to access the abdominal cavity and pelvic regions via small incisions called ports. Compared to open surgery, laparoscopy's small incision size better protects a patient's health and reduces recovery time. However, restricted rotation of the tools around chosen port locations can limit a surgeon's mobility while operating. To address this, the Novel Single Incision, Free Motion (SIFM) Laparoscopic Surgical System was created, and its design was explored through three experiments. Experiment 1 analyzed different permanent magnetic configurations to optimize the magnetic force between a tool on the inside of the abdominal wall and an external tool. The chosen configuration was a single pole external magnet, coupled to an axially magnetized internal magnet. Experiment 2 analyzed the experimental and theoretical forces applied by the internal tool. The tool was able to provide sufficient cutting forces at 26.1 mm of separation between the tools. Experiment 3 measured the precision of the tool's end effector which was controlled by a stepper motor powered cable system. The tool's end effector rotates no more than 1 degree about the y axis and no more than 2 degrees about the x axis. The SIFM system combines the health benefits of minimally invasive laparoscopic surgery, with the free motion and ease of open surgery.
{"title":"Design of the Novel Single Incision, Free Motion Laparoscopic Surgical System","authors":"Samson Galvin, R. Yanalitis, Eric Leon, J. Winder, R. Haluck, P. von Lockette, J. Moore","doi":"10.1115/1.4062178","DOIUrl":"https://doi.org/10.1115/1.4062178","url":null,"abstract":"\u0000 Laparoscopic surgery is a common minimally invasive surgery that uses specialized tools to access the abdominal cavity and pelvic regions via small incisions called ports. Compared to open surgery, laparoscopy's small incision size better protects a patient's health and reduces recovery time. However, restricted rotation of the tools around chosen port locations can limit a surgeon's mobility while operating. To address this, the Novel Single Incision, Free Motion (SIFM) Laparoscopic Surgical System was created, and its design was explored through three experiments. Experiment 1 analyzed different permanent magnetic configurations to optimize the magnetic force between a tool on the inside of the abdominal wall and an external tool. The chosen configuration was a single pole external magnet, coupled to an axially magnetized internal magnet. Experiment 2 analyzed the experimental and theoretical forces applied by the internal tool. The tool was able to provide sufficient cutting forces at 26.1 mm of separation between the tools. Experiment 3 measured the precision of the tool's end effector which was controlled by a stepper motor powered cable system. The tool's end effector rotates no more than 1 degree about the y axis and no more than 2 degrees about the x axis. The SIFM system combines the health benefits of minimally invasive laparoscopic surgery, with the free motion and ease of open surgery.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45680464","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}
Endotracheal Intubation is a medical procedure whereupon a physician or trained personnel inserts a breathing tube into a patient's mouth, through their vocal cords, and into their trachea. Intubation can be lifesaving when a patient cannot breathe on their own. Intubations are performed routinely, with approximately 15 million performed annually just in the Operating Room (OR) with an additional 650,000 intubations in the wider hospital environment. Intubation is a complex, dynamic, and at times difficult procedure with major consequences if delayed and/or if the procedure fails. Complications for intubations outside of the operating room are reported as high as 27%, with the most common being hypoxia, or low oxygen levels. We have developed a simple, sterile attachment that directs oxygen down endotracheal tubes during intubation. In animal studies the device has been shown to significantly reduce hypoxia; thereby increasing the time a medical provider has to safely perform the procedure. While further development is warranted, as well as additional testing both in vitro and in vivo, the cap assembly appears to provide a viable solution to a persistent and dangerous problem in medicine
{"title":"Development of an Endotracheal Tube Cap for Oxygen Delivery During Intubation","authors":"K. Hart, C. Salvino, Todd Pashak, B. Veatch","doi":"10.1115/1.4062151","DOIUrl":"https://doi.org/10.1115/1.4062151","url":null,"abstract":"\u0000 Endotracheal Intubation is a medical procedure whereupon a physician or trained personnel inserts a breathing tube into a patient's mouth, through their vocal cords, and into their trachea. Intubation can be lifesaving when a patient cannot breathe on their own. Intubations are performed routinely, with approximately 15 million performed annually just in the Operating Room (OR) with an additional 650,000 intubations in the wider hospital environment. Intubation is a complex, dynamic, and at times difficult procedure with major consequences if delayed and/or if the procedure fails. Complications for intubations outside of the operating room are reported as high as 27%, with the most common being hypoxia, or low oxygen levels. We have developed a simple, sterile attachment that directs oxygen down endotracheal tubes during intubation. In animal studies the device has been shown to significantly reduce hypoxia; thereby increasing the time a medical provider has to safely perform the procedure. While further development is warranted, as well as additional testing both in vitro and in vivo, the cap assembly appears to provide a viable solution to a persistent and dangerous problem in medicine","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44793670","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}
Abstract Three-dimensional bioprinting is a rapidly growing field attempting to recreate functional tissues for medical and pharmaceutical purposes. Development of functional tissue requires deposition of multiple biomaterials encapsulating multiple cell types, i.e., bio-ink necessitating switching ability between bio-inks. Existing systems use more than one print head to achieve this complex interchangeable deposition, decreasing efficiency, structural integrity, and accuracy. Therefore, the objective of this paper is to develop an alternative deposition system that will not require more than one print head for multimaterial bioprinting. To achieve that objective, we developed a nozzle system capable of switching between multiple bio-inks with continuous deposition, ensuring the minimum transition distance so that precise deposition transitioning can be achieved. This research progressed from a prototyping stage of nozzle system to the final selection of the system. Finally, the effect of rheological properties of different biomaterial compositions on the transition distance is investigated by fabricating the sample scaffolds.
{"title":"Designing an Interchangeable Multi-Material Nozzle System for the Three-Dimensional Bioprinting Process","authors":"Cartwright Nelson, Slesha Tuladhar, MD Habib","doi":"10.1115/1.4055249","DOIUrl":"https://doi.org/10.1115/1.4055249","url":null,"abstract":"Abstract Three-dimensional bioprinting is a rapidly growing field attempting to recreate functional tissues for medical and pharmaceutical purposes. Development of functional tissue requires deposition of multiple biomaterials encapsulating multiple cell types, i.e., bio-ink necessitating switching ability between bio-inks. Existing systems use more than one print head to achieve this complex interchangeable deposition, decreasing efficiency, structural integrity, and accuracy. Therefore, the objective of this paper is to develop an alternative deposition system that will not require more than one print head for multimaterial bioprinting. To achieve that objective, we developed a nozzle system capable of switching between multiple bio-inks with continuous deposition, ensuring the minimum transition distance so that precise deposition transitioning can be achieved. This research progressed from a prototyping stage of nozzle system to the final selection of the system. Finally, the effect of rheological properties of different biomaterial compositions on the transition distance is investigated by fabricating the sample scaffolds.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136178984","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. M. Mau, Sunandita Sarker, Seth P Harris, Benjamin Terry
Ingestible devices have become a popular means for diagnosing and treating the gastrointestinal (GI) tract due to their noninvasive nature. However, their residency period in the GI tract is limited by the transit time through it. In previous work, we designed a tissue attachment mechanism (TAM) inspired by parasitic worms' attachment methods, which were tested for implanting biosensors or drug delivery payloads to the small intestine with a swallowable capsule robot. In that work, the attachment success rate was 91.7%, and the average attachment duration of the TAM was 32.2 hours after factorial optimization of major design factors. This work develops a novel nitinol TAM (NTAM) for improving the attachment duration using the shape-changing properties of nitinol. The attachment strength of the NTAM to the intestinal tissue was assessed ex vivo and in vivo. The attachment duration of the NTAMs in live porcine models was evaluated from radiographic images, and histological analysis of the attachment location of an NTAM was performed after euthanasia. The NTAM was 100% successful in an attachment strength study and achieved a maximum attachment duration of 13 days, while the average attachment duration was 85.63±77.83 hours. Histological analysis did not report any permanent damage to the tissue. This work shows a 2.7-fold improvement in attachment duration over the previous design. This work has demonstrated a method of prolonged attachment to the intestinal wall through a swallowable device, which can be used for long-term drug delivery or biosensing.
{"title":"Design and Testing of a Superelastic Nitinol Tissue Attachment Mechanism for Long-term Gastrointestinal Device Retention","authors":"M. M. Mau, Sunandita Sarker, Seth P Harris, Benjamin Terry","doi":"10.1115/1.4057058","DOIUrl":"https://doi.org/10.1115/1.4057058","url":null,"abstract":"\u0000 Ingestible devices have become a popular means for diagnosing and treating the gastrointestinal (GI) tract due to their noninvasive nature. However, their residency period in the GI tract is limited by the transit time through it. In previous work, we designed a tissue attachment mechanism (TAM) inspired by parasitic worms' attachment methods, which were tested for implanting biosensors or drug delivery payloads to the small intestine with a swallowable capsule robot. In that work, the attachment success rate was 91.7%, and the average attachment duration of the TAM was 32.2 hours after factorial optimization of major design factors. This work develops a novel nitinol TAM (NTAM) for improving the attachment duration using the shape-changing properties of nitinol. The attachment strength of the NTAM to the intestinal tissue was assessed ex vivo and in vivo. The attachment duration of the NTAMs in live porcine models was evaluated from radiographic images, and histological analysis of the attachment location of an NTAM was performed after euthanasia. The NTAM was 100% successful in an attachment strength study and achieved a maximum attachment duration of 13 days, while the average attachment duration was 85.63±77.83 hours. Histological analysis did not report any permanent damage to the tissue. This work shows a 2.7-fold improvement in attachment duration over the previous design. This work has demonstrated a method of prolonged attachment to the intestinal wall through a swallowable device, which can be used for long-term drug delivery or biosensing.","PeriodicalId":49305,"journal":{"name":"Journal of Medical Devices-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46122770","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}
Levent Aydin, Ayfer Peker Karatoprak, Serdar Kucuk
Abstract Three-dimensional bioprinting offers a novel strategy to create large-scale complex tissue models. Nowadays, layer by layer fabrication is used to create patient specific tissue substitutes. However, commercially available bioprinters cannot be widely used especially in small research facilities due to their high cost, and may not be suitable for bioprinting of complex tissue models. Besides, most of the systems are not capable of providing the required working conditions. The aim of this study is to design and assemble of a low-cost H-Bot based bioprinter that allows multimicro-extrusion to form complex tissue models in a closed cabin and sterile conditions. In this study, a micro-extrusion based bioprinter, Bio-Logic, with three different print heads, namely, Universal Micro-Extrusion Module (UMM), Multi-Micro-Extrusion Module (MMM), and Ergonomic Multi-Extrusion Module (EMM) were developed. The print heads were tested and scaffold models were bioprinted and analyzed. Bio-Logic was compared in price with the commercially available bioprinters. Scaffold fabrication was successfully performed with Bio-Logic. The average pore size of the scaffold was determined as 0.37±0.04 mm (n = 20). Total cost of Bio-Logic was considerably less than any other commercially available bioprinters. A new system is developed for bioprinting of complex tissue models. The cost of the system is appropriate for research and features of the device may be upgraded according to the needs. Bio-Logic is the first H-Bot kinematics based bioprinter and has ability to measure atmospheric conditions in a closed cabin.
三维生物打印提供了一种创建大型复杂组织模型的新策略。现在，一层一层的制造被用来制造病人特定的组织替代品。然而，市面上的生物打印机由于成本高而不能广泛应用，特别是在小型研究机构中，并且可能不适合复杂组织模型的生物打印。此外，大多数系统无法提供所需的工作条件。本研究的目的是设计和组装一种低成本的基于H-Bot的生物打印机，该打印机可以在封闭的机舱和无菌条件下进行多微挤压形成复杂的组织模型。本研究开发了一种基于微挤压的生物打印机Bio-Logic，该打印机具有三种不同的打印头，即通用微挤压模块(UMM)，多微挤压模块(MMM)和人体工程学多挤压模块(EMM)。对打印头进行了测试，并对支架模型进行了生物打印和分析。Bio-Logic在价格上与市售生物打印机进行了比较。利用Bio-Logic成功地完成了支架的制作。测定支架的平均孔径为0.37±0.04 mm (n = 20)。Bio-Logic的总成本大大低于任何其他商用生物打印机。开发了一种用于复杂组织模型生物打印的新系统。该系统的成本适合研究，设备的功能可根据需要进行升级。Bio-Logic是第一个基于H-Bot运动学的生物打印机，能够测量封闭舱内的大气条件。
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