Publications

2013
C. Pardo-Martin, et al., “Minimally-invasive device for rapid urethrovesical anastomosis,” in ASME Design of Medical Devices Conference (extended abstract, poster), Minneapolis, MN, 2013. PDF
Q. Wan, et al., “Multifunctional laparoscopic trocar with built-in fascial closure and stabilization,” in ASME Design of Medical Devices Conference (extended abstract, poster), Minneapolis, MN, 2013. PDF
D. Holland, C. J. Walsh, and G. J. Bennett, “Tools for assessing student learning in mechanical design courses,” in 9th International CDIO Conference (poster), Cambridge, MA, 2013. PDF
Y. Menguc, et al., “Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements, (extended abstract),” in International Workshop on Soft Robotics and Morphological Computation, 2013.Abstract

Motion sensing has played an important role in
the study of human biomechanics as well as the entertainment
industry. Although existing technologies, such as optical or
inertial based motion capture systems, have relatively high
accuracy in detecting body motions, they still have inherent
limitations with regards to mobility and wearability. In this
paper, we present a soft motion sensing suit for measuring lower
extremity joint motion. The sensing suit prototype includes a
pair of elastic tights and three hyperelastic strain sensors. The
strain sensors are made of silicone elastomer with embedded
microchannels filled with conductive liquid. To form a sensing
suit, these sensors are attached at the hip, knee, and ankle areas
to measure the joint angles in the sagittal plane. The prototype
motion sensing suit has significant potential as an autonomous
system that can be worn by individuals during many activities
outside the laboratory, from running to rock climbing. In this
study we characterize the hyperelastic sensors in isolation to
determine their mechanical and electrical responses to strain,
and then demonstrate the sensing capability of the integrated
suit in comparison with a ground truth optical motion capture
system. Using simple calibration techniques, we can accurately
track joint angles and gait phase. Our efforts result in a
calculated trade off: with a maximum error less than 8%, the
sensing suit does not track joints as accurately as optical motion
capture, but its wearability means that it is not constrained to
use only in a lab.

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P. Polygerinos, D. Holland, G. J. Bennett, and C. J. Walsh, “Towards Educational Kits for Soft Robotics applied to Medical Device Design,” in 2013 International Workshop on Soft Robotics and Morphological Computation, 2013. PDF
Y. Menguc, et al., “Soft Wearable Motion Sensing Suit for Lower Limb Biomechanics Measurements,” in 2013 IEEE International Conference on Robotics and Automation (ICRA), Karlsruhe, Germany, 2013, pp. 5309-5316. Publisher's VersionAbstract

Motion sensing has played an important role in the study of human biomechanics as well as the entertainment industry. Although existing technologies, such as optical or inertial based motion capture systems, have relatively high accuracy in detecting body motions, they still have inherent limitations with regards to mobility and wearability. In this paper, we present a soft motion sensing suit for measuring lower extremity joint motion. The sensing suit prototype includes a pair of elastic tights and three hyperelastic strain sensors. The strain sensors are made of silicone elastomer with embedded microchannels filled with conductive liquid. To form a sensing suit, these sensors are attached at the hip, knee, and ankle areas to measure the joint angles in the sagittal plane. The prototype motion sensing suit has significant potential as an autonomous system that can be worn by individuals during many activities outside the laboratory, from running to rock climbing. In this study we characterize the hyperelastic sensors in isolation to determine their mechanical and electrical responses to strain, and then demonstrate the sensing capability of the integrated suit in comparison with a ground truth optical motion capture system. Using simple calibration techniques, we can accurately track joint angles and gait phase. Our efforts result in a calculated trade off: with a maximum error less than 8%, the sensing suit does not track joints as accurately as optical motion capture, but its wearability means that it is not constrained to use only in a lab.

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P. Polygerinos, et al., “Towards a Soft Pneumatic Glove for Hand Rehabilitation,” in 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Tokyo, Japan, 2013. Publisher's VersionAbstract

This paper presents preliminary results for the design, development and evaluation of a hand rehabilitation glove fabricated using soft robotic technology. Soft actuators comprised of elastomeric materials with integrated channels that function as pneumatic networks (PneuNets), are designed and geometrically analyzed to produce bending motions that can safely conform with the human finger motion. Bending curvature and force response of these actuators are investigated using geometrical analysis and a finite element model (FEM) prior to fabrication. The fabrication procedure of the chosen actuator is described followed by a series of experiments that mechanically characterize the actuators. The experimental data is compared to results obtained from FEM simulations showing good agreement. Finally, an open-palm glove design and the integration of the actuators to it are described, followed by a qualitative evaluation study.

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N. C. Hanumara, et al., “Classroom to Clinic: Merging Education and Research to Efficiently Prototype Medical Devices,” IEEE Journal of Translational Engineering in Health and Medicine, vol. 1, pp. 4700107, 2013. Publisher's VersionAbstract

Innovation in patient care requires both clinical and technical skills, and this paper presents the methods and outcomes of a nine-year, clinical-academic collaboration to develop and evaluate new medical device technologies, while teaching mechanical engineering. Together, over the course of a single semester, seniors, graduate students, and clinicians conceive, design, build, and test proof-of-concept prototypes. Projects initiated in the course have generated intellectual property and peer-reviewed publications, stimulated further research, furthered student and clinician careers, and resulted in technology licenses and start-up ventures.

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2012
B. J. Hopkins, et al., “Hemodialysis graft resistance adjustment device,” ASME Journal of Medical Devices, vol. 6, pp. 021011-021016, 2012.Abstract

Up to eight percent of patients develop steal syndrome after prosthetic dialysis access graft placement, which is characterized by low blood flow to the hand. Steal syndrome results in a cold hand, pain, and in extreme cases, loss of function and tissue damage. A practical and easy way of adjusting the fluidic resistance in a graft to attenuate the risk of steal physiology would greatly benefit both surgeons and patients. This paper describes the design and development of a device that can be attached to a dialysis access graft at the time of surgical implantation to enable providers to externally adjust the resistance of the graft postoperatively. Bench level flow experiments and magnetic setups were used to establish design requirements and test prototypes. The Graft Resistance Adjustment Mechanism (GRAM) can be applied to a standard graft before or after it is implanted and a non-contact magnetic coupling enables actuation through the skin for graft compression. The device features a winch-driven system to provide translational movement for a graft compression unit. We expect such a device to enable noninvasive management of steal syndrome in a manner that does not change the existing graft and support technologies, thus reducing patient complications and reducing costs to hospitals.

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C. M. Graves, A. H. Slocum, R. Gupta, and C. J. Walsh, “Towards a Compact Robotically Steerable Thermal Ablation Probe,” in Proceedings of the IEEE International Conference on Robotics and Automation, Saint Paul, Minnesota, 2012, pp. 709-714. PDF
D. Holland, C. J. Walsh, and G. J. Bennett, “Troublesome knowledge in engineering design courses,” in 6th Annual Conference of the National Academy for the Integration of Research, Teaching and Learning, and the 4th Biennial Threshold Concepts Conference, Trinity College Dublin, Ireland, 2012. PDF
C. - H. Yeow, A. T. Baisch, R. D. Howe, S. G. Talbot, and C. J. Walsh, “Differential Spring Stiffness Design for Finger Therapy Device,” in ASME Design of Medical Devices Conference, Minneapolis, MN, 2012. PDF
N. C. Hanumara, C. J. Walsh, L. R. Osborn, R. Gupta, and A. H. Slocum, “Classroom to Clinic: Merging Education and Research to Efficiently Prototype Medical Devices,” in Proceedings of the 2012 IEEE Healthcare Innovation Conference: Translational Engineering in Health & Medicine, Methodist Hospital Research Institute, Houston, TX, 2012. PDF
E. Goldfield, et al., “Bio-Inspired Design of Soft Robotic Assistive Devices: The Interface of Physics, Biology, and Behavior,” Ecological Psychology, vol. 24, no. 4, pp. 300-327, 2012. Publisher's VersionAbstract

Wearable assistive robotic devices are characterized by an interface, a meeting place of living tissue and mechanical forces, at which potential and kinetic energy are converted to one or the other form. Ecological scientists may make important contributions to the design of device interfaces because of a functional perspective on energy and information exchange. For ecological scientists, (a) behavioral forms are an assembly of whole functional systems from available parts, emerging in energy flows, and (b) nature explores for informationally based adaptive solutions to assemble behavioral forms by generating spontaneous patterns containing fluctuations. We present data from ongoing studies with infants that demonstrate how infants may explore for adaptive kicking solutions. Inspired by the ecological perspective and data from developing humans, ecological scientists may design interfaces to assist individuals with medical conditions that result in physical and/or mental impairment. We present one such device, what is called the “second skin,” to illustrate how a soft, prestressed material, worn on the skin surface, may be used synergistically with synthetic and biological muscles for assisting action. Our work on the second skin, thus far, suggests a set of ecologically inspired principles for design of wearable assistive robotic devices.

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P. Loschak, K. Xiao, H. Pei, S. B. Kesner, A. J. Thomas, and C. J. Walsh, “Cranial Drilling Tool with Retracting Drill Bit Upon Skull Penetration,” in ASME Design of Medical Devices Conference, Minneapolis, MN, 2012. PDF
C. J. Walsh, Meskers, A. H. Slocum, and R. Gupta, “CT-Compatible Medical Drilling Stylet for Percutaneous Interventions,” ASME Journal of Medical Devices, vol. 6, no. 4, pp. 041001, 2012. Publisher's Version PDF
M. Wehner, et al., “Experimental Characterization of Components for Active Soft Orthotics,” in IEEE International Conference on Biomedical Robotics and Biomechatronics, Rome, Italy, 2012, pp. 1586-1592. PDF
2011
C. J. Walsh, J. C. Franklin, A. H. Slocum, and R. Gupta, “Design of a robotic tool for percutaneous instrument distal tip repositioning,” in 33rd Annual International Conference of the IEEE EMBS, Boston, MA, 2011, pp. 2097-2100. PDF
L. J. Brattain, et al., “Design of an Ultrasound Needle Guidance System,” in 33rd Annual International Conference of the IEEE EMBS, Boston, MA, 2011, pp. 8090-8093.Abstract

In this paper, we describe our prototype of an ultrasound guidance system to address the need for an easy-touse, cost-effective, and portable technology to improve ultrasound-guided procedures. The system consists of a lockable, articulating needle guide that attaches to an ultrasound probe and a user-interface that provides real-time visualization of the predicted needle trajectory overlaid on the ultrasound image. Our needle guide ensures proper needle alignment with the ultrasound imaging plane. Moreover, the calculated needle trajectory is superimposed on the real-time ultrasound image, eliminating the need for the practitioner to estimate the target trajectory, and thereby reducing injuries from needle readjustment. Finally, the guide is lockable to prevent needle deviation from the desired trajectory during insertion. This feature will also allow the practitioner to free one hand to complete simple tasks that usually require a second practitioner to perform. Overall, our system eliminates the experience required to develop the fine hand movement and dexterity needed for traditional ultrasound-guided procedures. The system has the potential to increase efficiency, safety, quality, and reduce costs for a wide range of ultrasound-guided procedures. Furthermore, in combination with portable ultrasound machines, this system will enable these procedures to be more easily performed by unskilled practitioners in non-ideal situations such as the battlefield and other disaster relief areas.

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M. S. Berns, et al., “Single Entry Tunneler [SET] for Hemodialysis Graft Procedures,” in ASME Design of Medical Devices Conference, Minneapolis, Minnesota, USA, 2011. PDF

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