Publications by Year: 2013

R. J. Wood and C. J. Walsh, “Smaller, Softer, Safer, Smarter Robots,” Science Translational Medicine, vol. 5, no. 210, pp. 210ed19, 2013. Publisher's Version PDF
P. Polygerinos, et al., “Soft Elastomeric Actuators with Fiber Reinforcement,” Materials and Research Society (MRS) Fall Meeting & Exhibit. 2013. PDF
J. Gafford, S. B. Kesner, R. J. Wood, and C. J. Walsh, “Microsurgical devices by Pop-up Book MEMS,” in Proceedings of the ASME 2013 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2013, Portland, Oregon, USA, 2013. PDF
P. Loschak, K. Xiao, H. Pei, S. B. Kesner, A. J. Thomas, and C. J. Walsh, “Assured Safety Drill with Bi-stable Bit Retraction Mechanism,” in Proceedings of the ASME 2013 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2013, Portland, OR, 2013.Abstract

A handheld, portable cranial drilling tool for safely creating holes in the skull without damaging brain tissue is presented. Such a device is essential for neurosurgeons and mid-level practitioners treating patients with traumatic brain injury. A typical procedure creates a small hole for inserting sensors to monitor intra-cranial pressure measurements and/or removing excess fluid. Drilling holes in emergency settings with existing tools is difficult and dangerous due to the risk of a drill bit unintentionally plunging into brain tissue. Cranial perforators, which counter-bore holes and automatically stop upon skull penetration, do exist but are limited to large diameter hole size and an operating room environment. The tool presented here is compatible with a large range of bit diameters and provides safe, reliable access. This is accomplished through a dynamic bi-stable linkage that supports drilling when force is applied against the skull but retracts upon penetration when the reaction force is diminished. Retraction is achieved when centrifugal forces from rotating masses overpower the axial forces, thus changing the state of the bi-stable mechanism. Initial testing on ex-vivo animal structures has demonstrated that the device can withdraw the drill bit in sufficient time to eliminate the risk of soft tissue damage. Ease of use and portability of the device will enable its use in unregulated environments such as hospital emergency rooms and emergency disaster relief areas.

M. Wehner, et al., “A Lightweight Soft Exosuit for Gait Assistance,” in IEEE International Conference on Robotics and Automation (ICRA), Karlsruhe, Germany, 2013. PDF
A. T. Asbeck, R. J. Dyer, A. F. Larusson, and C. J. Walsh, “Biologically-inspired Soft Exosuit,” in 13th International Conference on Rehabilitation Robotics (ICORR), Seattle, WA, 2013, pp. 24-26. Publisher's VersionAbstract

In this paper, we present the design and evaluation of a novel soft cable-driven exosuit that can apply forces to the body to assist walking. Unlike traditional exoskeletons which contain rigid framing elements, the soft exosuit is worn like clothing, yet can generate moments at the ankle and hip with magnitudes of 18% and 30% of those naturally generated by the body during walking, respectively. Our design uses geared motors to pull on Bowden cables connected to the suit near the ankle. The suit has the advantages over a traditional exoskeleton in that the wearer's joints are unconstrained by external rigid structures, and the worn part of the suit is extremely light, which minimizes the suit's unintentional interference with the body's natural biomechanics. However, a soft suit presents challenges related to actuation force transfer and control, since the body is compliant and cannot support large pressures comfortably. We discuss the design of the suit and actuation system, including principles by which soft suits can transfer force to the body effectively and the biological inspiration for the design. For a soft exosuit, an important design parameter is the combined effective stiffness of the suit and its interface to the wearer. We characterize the exosuit's effective stiffness, and present preliminary results from it generating assistive torques to a subject during walking. We envision such an exosuit having broad applicability for assisting healthy individuals as well as those with muscle weakness.

E. T. Roche, et al., “Biomaterial delivery vehicles improve acute retention of cells in the infarcted heart,” American Heart Association’s Scientific Sessions. 2013. Abstract Poster
E. Roche, A. Menz, P. Hiremath, N. V. Vasilyev, and C. J. Walsh, “Design and fabrication of a soft, anatomically accurate, patient-specific cardiac simulator with sensing and controls,” International Workshop on Soft Robotics and Morphological Computation. 2013. PDF
J. Gafford, S. B. Kesner, R. J. Wood, and C. J. Walsh, “Force-Sensing Surgical Grasper Enabled by Pop-Up Book MEMS,” in 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Tokyo, Japan, 2013, pp. 2552-2558. Publisher's VersionAbstract

The small scale of minimally-invasive surgery (MIS) presents significant challenges to developing robust, smart, and dexterous tools for manipulating millimeter and sub-millimeter anatomical structures (vessels, nerves) and surgical equipment (sutures, staples). Robotic MIS systems offer the potential to transform this medical field by enabling precise repair of these miniature tissue structures through the use of teleoperation and haptic feedback. However, this effort is currently limited by the inability to make robust and accurate MIS end effectors with integrated force and contact sensing. In this paper, we demonstrate the use of the novel Pop-Up Book MEMS manufacturing method to fabricate the mechanical and sensing elements of an instrumented MIS grasper. A custom thin-foil strain gage was manufactured in parallel with the mechanical components of the grasper to realize a fully-integrated electromechanical system in a single manufacturing step, removing the need for manual assembly, bonding and alignment. In preliminary experiments, the integrated grasper is capable of resolving forces as low as 30 mN, with a sensitivity of approximately 408 mV/N. This level of performance will enable robotic surgical systems that can handle delicate tissue structures and perform dexterous procedures through the use of haptic feedback guidance.

D. Orozco, et al., “Laproscopic tool with adjustable sponge at distal tip for direct/indirect suction modulation,” ASME Design of Medical Devices Conference. 2013. PDF
C. J. Walsh, “A Lightweight Soft Exosuit for Gait Assistance,” International Workshop on Soft Robotics and Morphological Computation. 2013. PDF
K. C. Galloway, P. Polygerinos, C. J. Walsh, and R. J. Wood, “Mechanically Programmable Bend Radius for Fiber-Reinforced Soft Actuators,” in 16th International Conference on Advanced Robotics (ICAR), Montevideo, Uruguay, 2013, pp. 1-6. Publisher's VersionAbstract

Established design and fabrication guidelines exist for achieving a variety of motions with soft actuators such as bending, contraction, extension, and twisting. These guidelines typically involve multi-step molding of composite materials (elastomers, paper, fiber, etc.) along with specially designed geometry. In this paper we present the design and fabrication of a robust, fiber-reinforced soft bending actuator where its bend radius and bending axis can be mechanically-programed with a flexible, selectively-placed conformal covering that acts to mechanically constrain motion. Several soft actuators were fabricated and their displacement and force capabilities were measured experimentally and compared to demonstrate the utility of this approach. Finally, a prototype two-digit end-effector was designed and programmed with the conformal covering to shape match a rectangular object. We demonstrated improved gripping force compared to a pure bending actuator. We envision this approach enabling rapid customization of soft actuator function for grasping applications where the geometry of the task is known a priori.

C. Pardo-Martin, et al., “Minimally-invasive device for rapid urethrovesical anastomosis,” ASME Design of Medical Devices Conference. 2013. PDF
Q. Wan, et al., “Multifunctional laparoscopic trocar with built-in fascial closure and stabilization,” ASME Design of Medical Devices Conference. 2013. PDF
P. M. Aubin, H. Sallum, C. J. Walsh, A. Correia, and L. Stirling, “A Pediatric Robotic Thumb Exoskeleton for at-Home Rehabilitation: The Isolated Orthosis for Thumb Actuation (IOTA),” in 13th International Conference on Rehabilitation Robotics (ICORR), University of Washington, 2013. PDF
F. Y. Wu, et al., “An MRI Coil Mounted Multi-probe robotic positioner for cryoablation,” in Proceedings of the ASME 2013 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, Portland, Oregon, USA, 2013. PDF
E. T. Roche, et al., “Physiological and Pathological Cardiac Motion Generation Using a Soft Robotic Approach,” Materials Research Society (MRS) Fall Meeting. 2013. Abstract Poster
D. Holland, C. J. Walsh, and G. J. Bennett, “An assessment of student needs in project-based mechanical design courses,” in 120th ASEE Annual Conference and Exposition (paper and presentation), Atlanta, GA, 2013. PDF
S. C. Obiajulu, E. T. Roche, F. A. Pigula, and C. J. Walsh, “Soft Pneumatic Artificial Muscles with Low Threshold Pressures for Cardiac Compression Device,” in Proceedings of the ASME 2013 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2013, Portland, OR, 2013. Publisher's Version 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.