Publications by Type: Journal Article

C. J. Walsh, J. T. Heaton, J. B. Kobler, T. L. Szabo, and S. M. Zeitels, “Imaging of the Calf Vocal Fold with High Frequency Ultrasound,” The Laryngoscope, vol. 118, no. Oct. pp. 1894-1899, 2008. PDF
C. J. Walsh and C. K. Kearney, “Engineering, Science and Medicine: Transforming Healthcare,” Royal College of Surgeons in Ireland Student Medical Journal, vol. 1, no. 1, pp. 56-59, 2008. PDF
C. J. Walsh, N. C. Hanumara, A. H. Slocum, J. - A. Shepard, and R. Gupta, “A Patient-Mounted, Telerobotic Tool for CT-Guided Percutaneous Interventions,” ASME Journal of Medical Devices, vol. 2, no. 1, 2008. PDF
C. J. Walsh, K. Endo, and H. Herr, “Quasi-Passive Leg Exoskeleton for Load Carrying Augmentation,” International Journal of Humanoid Robotics, Special Issue: Active Exoskeletons, vol. 4, no. 3, pp. 487-506, 2007.Abstract

A quasi-passive leg exoskeleton is presented for load-carrying augmentation during walking. The exoskeleton has no actuators, only ankle and hip springs and a knee variable damper. Without a payload, the exoskeleton weighs 11.7kg and requires only 2 Watts of electrical power during loaded walking. For a 36kg payload, we demonstrate that the quasi-passive exoskeleton transfers on average 80% of the load to the ground during the single support phase of walking. By measuring the rate of oxygen consumption on a study participant walking at a self-selected speed, we find that the exoskeleton slightly increases the walking metabolic cost of transport (COT) as compared to a standard loaded backpack (10% increase). However, a similar exoskeleton without joint springs or damping control (zero-impedance exoskeleton) is found to increase COT by 23% compared to the loaded backpack, highlighting the benefits of passive and quasi-passive joint mechanisms in the design of efficient, low-mass leg exoskeletons.