@proceedings {1299883, title = {Ankle Optimization with a Soft Exosuit Reduces Metabolic Cost of Loaded Walking}, journal = {International Symposium on Wearable Robotics (WeRob)}, year = {2017}, address = {Houston, TX, November 5-8}, author = {Lauren Baker and Lee, Sangjun and Long, Andrew and Jinsoo Kim and Nikos Karavas and Ignacio Galiana and Conor Walsh} } @proceedings {1299880, title = {Autonomous soft exosuit with hip extension assistance for overground walking and jogging}, journal = {International Symposium on Wearable Robotics (WeRob)}, year = {2017}, address = {Houston, TX, November 5-8}, author = {Dabin Choe and Jinsoo Kim and Lee, Giuk and Nikos Karavas and Nicolas Menard and Conor Walsh} } @article {Payneeaan6736, title = {Soft robotic ventricular assist device with septal bracing for therapy of heart failure}, journal = {Science Robotics}, volume = {2}, number = {12}, year = {2017}, publisher = {Science Robotics}, abstract = {Previous soft robotic ventricular assist devices have generally targeted biventricular heart failure and have not engaged the interventricular septum that plays a critical role in blood ejection from the ventricle. We propose implantable soft robotic devices to augment cardiac function in isolated left or right heart failure by applying rhythmic loading to either ventricle. Our devices anchor to the interventricular septum and apply forces to the free wall of the ventricle to cause approximation of the septum and free wall in systole and assist with recoil in diastole. Physiological sensing of the native hemodynamics enables organ-in-the-loop control of these robotic implants for fully autonomous augmentation of heart function. The devices are implanted on the beating heart under echocardiography guidance. We demonstrate the concept on both the right and the left ventricles through in vivo studies in a porcine model. Different heart failure models were used to demonstrate device function across a spectrum of hemodynamic conditions associated with right and left heart failure. These acute in vivo studies demonstrate recovery of blood flow and pressure from the baseline heart failure conditions. Significant reductions in diastolic ventricle pressure were also observed, demonstrating improved filling of the ventricles during diastole, which enables sustainable cardiac output.}, doi = {10.1126/scirobotics.aan6736}, url = {http://robotics.sciencemag.org/content/2/12/eaan6736}, author = {Payne, Christopher J. and Wamala, Isaac and Bautista-Salinas, Daniel and Saeed, Mossab and Van Story, David and Thalhofer, Thomas and Markus A. Horvath and Abah, Colette and Pedro J. del Nido and Walsh, Conor J. and Nikolay V. Vasilyev} } @article {1258411, title = {Highly Sensitive Capacitive-Based Soft Pressure Sensor Based on Conductive Fabric and Micro-porous Dielectric Layer}, journal = {Advanced Materials Technologies}, year = {2017}, abstract = {In this paper, the design and manufacturing of a highly sensitive capacitive-based soft pressure sensor for wearable electronics applications are presented. Toward this aim, two types of soft conductive fabrics (knitted and woven), as well as two types of sacrificial particles (sugar granules and salt crystals) to create micropores within the dielectric layer of the capacitive sensor are evaluated, and the combined effects on the sensor{\textquoteright}s overall performance are assessed. It is found that a combination of the conductive knit electrode and higher dielectric porosity (generated using the larger sugar granules) yields higher sensitivity (121 {\texttimes} 10-4\ kPa-1) due to greater compressibility and the formation of air gaps between silicone elastomer and conductive knit electrode among the other design considerations in this study. As a practical demonstration, the capacitive sensor is embedded into a textile glove for grasp motion monitoring during activities of daily living.}, url = {http://onlinelibrary.wiley.com/doi/10.1002/admt.201700237/abstract?systemMessage=Wiley+Online+Library+usage+report+download+page+will+be+unavailable+on+Friday+24th+November+2017+at+21\%3A00+EST+\%2F+02.00+GMT+\%2F+10\%3A00+SGT+\%28Saturday+25th+Nov+for+SGT+}, author = {Ozgur Atalay and Asli Atalay and Joshua Gafford and Conor J Walsh} } @article {Panizzolo4169, title = {Lower limb biomechanical analysis during an unanticipated step on a bump reveals specific adaptations of walking on uneven terrains}, journal = {Journal of Experimental Biology}, volume = {220}, number = {22}, year = {2017}, pages = {4169{\textendash}4176}, publisher = {The Company of Biologists Ltd}, abstract = {Although it is clear that walking over different irregular terrain is associated with altered biomechanics, there is little understanding of how we quickly adapt to unexpected variations in terrain. This study aims to investigate which adaptive strategies humans adopt when performing an unanticipated step on an irregular surface, specifically a small bump. Nine healthy male participants walked at their preferred walking speed along a straight walkway during five conditions: four involving unanticipated bumps of two different heights, and one level walking condition. Muscle activation of eight lower limb muscles and three-dimensional gait analysis were evaluated during these testing conditions. Two distinct adaptive strategies were found, which involved no significant change in total lower limb mechanical work or walking speed. An ankle-based strategy was adopted when stepping on a bump with the forefoot, whereas a hip-based strategy was preferred when stepping with the rearfoot. These strategies were driven by a higher activation of the plantarflexor muscles (6{\textendash}51\%), which generated a higher ankle joint moment during the forefoot conditions and by a higher activation of the quadriceps muscles (36{\textendash}93\%), which produced a higher knee joint moment and hip joint power during the rearfoot conditions. These findings provide insights into how humans quickly react to unexpected events and could be used to inform the design of adaptive controllers for wearable robots intended for use in unstructured environments that can provide optimal assistance to the different lower limb joints.}, issn = {0022-0949}, doi = {10.1242/jeb.161158}, url = {http://jeb.biologists.org/content/220/22/4169}, author = {Panizzolo, Fausto A. and Lee, Sangjun and Taira Miyatake and Rossi, Denise Martineli and Christopher Siviy and Jozefien Speeckaert and Ignacio Galiana and Walsh, Conor J.} } @article {1188321, title = {An Implantable Extracardiac Soft Robotic Device for the Failing Heart: Mechanical Coupling and Synchronization}, journal = {Soft Robotics}, volume = {4}, number = {3}, year = {2017}, pages = {241-250}, abstract = {Soft robotic devices have significant potential for medical device applications that warrant safe synergistic interaction with humans. This article describes the optimization of an implantable soft robotic system for heart failure whereby soft actuators wrapped around the ventricles are programmed to contract and relax in synchrony with the beating heart. Elastic elements integrated into the soft actuators provide recoiling function so as to aid refilling during the diastolic phase of the cardiac cycle. Improved synchronization with the biological system is achieved by incorporating the native ventricular pressure into the control system to trigger assistance and synchronize the device with the heart. A three-state electro-pneumatic valve configuration allows the actuators to contract at different rates to vary contraction patterns. An in vivo study was performed to test three hypotheses relating to mechanical coupling and temporal synchronization of the actuators and heart. First, that adhesion of the actuators to the ventricles improves cardiac output. Second, that there is a contraction{\textendash}relaxation ratio of the actuators which generates optimal cardiac output. Third, that the rate of actuator contraction is a factor in cardiac output.}, url = {https://doi.org/10.1089/soro.2016.0076}, author = {Payne, Christopher J. and Wamala, Isaac and Abah, Colette and Thalhofer, Thomas and Saeed, Mossab and Bautista-Salinas, Daniel and Markus A. Horvath and Nikolay V. Vasilyev and Roche, Ellen T. and Pigula, Frank A. and Walsh, Conor J.} } @article {10.1371/journal.pone.0184054, title = {Human-in-the-loop Bayesian optimization of wearable device parameters}, journal = {PLOS ONE}, volume = {12}, number = {9}, year = {2017}, month = {19 Sep, 2017}, pages = {1-15}, publisher = {Public Library of Science}, abstract = {The increasing capabilities of exoskeletons and powered prosthetics for walking assistance have paved the way for more sophisticated and individualized control strategies. In response to this opportunity, recent work on human-in-the-loop optimization has considered the problem of automatically tuning control parameters based on realtime physiological measurements. However, the common use of metabolic cost as a performance metric creates significant experimental challenges due to its long measurement times and low signal-to-noise ratio. We evaluate the use of Bayesian optimization{\textemdash}a family of sample-efficient, noise-tolerant, and global optimization methods{\textemdash}for quickly identifying near-optimal control parameters. To manage experimental complexity and provide comparisons against related work, we consider the task of minimizing metabolic cost by optimizing walking step frequencies in unaided human subjects. Compared to an existing approach based on gradient descent, Bayesian optimization identified a near-optimal step frequency with a faster time to convergence (12 minutes, p \< 0.01), smaller inter-subject variability in convergence time ({\textpm} 2 minutes, p \< 0.01), and lower overall energy expenditure (p \< 0.01).}, doi = {10.1371/journal.pone.0184054}, url = {https://doi.org/10.1371/journal.pone.0184054}, author = {Kim, Myunghee and Ye Ding and Philippe Malcolm and Jozefien Speeckaert and Siviy, Christoper J. and Walsh, Conor J. and Scott Kuindersma} } @proceedings {1135896, title = {Pop-up-inspired design of a septal anchor for a ventricular assist device}, journal = {ASME Design of Medical Devices Conference}, year = {2017}, address = {Minneapolis, MN, April 11-13}, author = {Temel, F.Z. and McClintock, H. and Payne, C. and Wamala, Isaac and Walsh, Conor J. and Nikolay V. Vasilyev and Wood, Robert J.} } @proceedings {1135891, title = {Approaches to Real-Time Ventricular Wall Strain Measurement for the Control of Soft Robotic Ventricular Assist Devices}, journal = {The 9th Hamlyn Symposium on Medical Robotics}, year = {2017}, address = {London, June 25-28}, author = {Van Story, David and Saeed, M. and Price, K. and Wamala, Isaac and Hammer, P. and Bautista-Salinas, Daniel and Daniel Vogt and Walsh, Conor J. and Wood, Robert J. and Nikolay V. Vasilyev} } @proceedings {1135886, title = {Exosuit-induced improvements in walking after stroke: comprehensive analysis on gait energetics and biomechanics}, journal = {International Symposium on Wearable Robotics (WeRob)}, year = {2017}, address = {Houston, TX, November 5-8}, author = {Jaehyun Bae and Louis N. Awad and Kathleen O{\textquoteright}Donnell and De Rossi, Stefano and Hendron, K. and Sloot, Lizeth and Kudzia, Pawel and Kenneth G. Holt and Ellis, T. and Walsh, Conor J.} } @proceedings {1135876, title = {Soft Exosuits Increase Walking Speed and Distance after Stroke}, journal = {International Symposium on Wearable Robotics (WeRob)}, year = {2017}, address = {Houston, TX, November 5-8}, author = {Louis N. Awad and Jaehyun Bae and Kathleen O{\textquoteright}Donnell and Hendron, Kathryn and Sloot, Lizeth and Christopher Siviy and Kudzia, Pawel and Kenneth G. Holt and Ellis, T. and Walsh, Conor J.} } @article {1132816, title = {Distal Proprioceptive Sensor for Motion Feedback in Endoscope-Based Modular Robotic Systems}, journal = {IEEE Robotics and Automation Letters}, volume = {PP}, year = {2017}, abstract = {Modular robotic systems that integrate with commercially-available endoscopic equipment have the potential to improve the standard-of-care in therapeutic endoscopy by granting clinicians with capabilities not present in commercial tools, such as precision dexterity and motion sensing. With the desire to integrate both sensing and actuation distally for closed-loop position control in fully-deployable, endoscope-based robotic modules, commercial sensor and actuator options that acquiesce to the strict form-factor requirements are sparse or nonexistent. Herein we describe a proprioceptive angle sensor for potential closed-loop position control applications in distal robotic modules. Fabricated monolithically using printed-circuit MEMS, the sensor employs a kinematic linkage and the principle of light intensity modulation to sense the angle of articulation with a high degree of fidelity. On-board temperature and environmental irradiance measurements, coupled with linear regression techniques, provide robust angle measurements that are insensitive to environmental disturbances. The sensor is capable of measuring +/-45 degrees of articulation with an RMS error of 0.98 degrees. An integrated demonstration shows that the sensor can give real-time proprioceptive feedback when coupled with an actuator module, opening up the possibility of fully-distal closed-loop control.}, url = {https://doi.org/10.1109/LRA.2017.2737042}, author = {Joshua B. Gafford and Aihara, Hiroyuki and Thompson, Christopher and Wood, Robert J. and Walsh, Conor J.} } @article {Awadeaai9084, title = {A soft robotic exosuit improves walking in patients after stroke}, journal = {Science Translational Medicine}, volume = {9}, number = {400}, year = {2017}, pages = {eaai9084}, publisher = {American Association for the Advancement of Science}, abstract = { Passive assistance devices such as canes and braces are often used by people after stroke, but mobility remains limited for some patients. Awad et al. studied the effects of active assistance (delivery of supportive force) during walking in nine patients in the chronic phase of stroke recovery. A soft robotic exosuit worn on the partially paralyzed lower limb reduced interlimb propulsion asymmetry, increased ankle dorsiflexion, and reduced the energy required to walk when powered on during treadmill and overground walking tests. The exosuit could be adjusted to deliver supportive force during the early or late phase of the gait cycle depending on the patient{\textquoteright}s needs. Although long-term therapeutic studies are necessary, the immediate improvement in walking performance observed using the powered exosuit makes this a promising approach for neurorehabilitation. Stroke-induced hemiparetic gait is characteristically slow and metabolically expensive. Passive assistive devices such as ankle-foot orthoses are often prescribed to increase function and independence after stroke; however, walking remains highly impaired despite{\textemdash}and perhaps because of{\textemdash}their use. We sought to determine whether a soft wearable robot (exosuit) designed to supplement the paretic limb{\textquoteright}s residual ability to generate both forward propulsion and ground clearance could facilitate more normal walking after stroke. Exosuits transmit mechanical power generated by actuators to a wearer through the interaction of garment-like, functional textile anchors and cable-based transmissions. We evaluated the immediate effects of an exosuit actively assisting the paretic limb of individuals in the chronic phase of stroke recovery during treadmill and overground walking. Using controlled, treadmill-based biomechanical investigation, we demonstrate that exosuits can function in synchrony with a wearer{\textquoteright}s paretic limb to facilitate an immediate 5.33 {\textpm} 0.91{\textdegree} increase in the paretic ankle{\textquoteright}s swing phase dorsiflexion and 11 {\textpm} 3\% increase in the paretic limb{\textquoteright}s generation of forward propulsion (P \< 0.05). These improvements in paretic limb function contributed to a 20 {\textpm} 4\% reduction in forward propulsion interlimb asymmetry and a 10 {\textpm} 3\% reduction in the energy cost of walking, which is equivalent to a 32 {\textpm} 9\% reduction in the metabolic burden associated with poststroke walking. Relatively low assistance (\ 12\% of biological torques) delivered with a lightweight and nonrestrictive exosuit was sufficient to facilitate more normal walking in ambulatory individuals after stroke. Future work will focus on understanding how exosuit-induced improvements in walking performance may be leveraged to improve mobility after stroke. }, issn = {1946-6234}, doi = {10.1126/scitranslmed.aai9084}, url = {http://stm.sciencemag.org/cgi/content/full/9/400/eaai9084?ijkey=K/pmOVs/Os2Xo\&keytype=ref\&siteid=scitransmed}, author = {Louis N. Awad and Jaehyun Bae and O{\textquoteright}Donnell, Kathleen and De Rossi, Stefano M.M. and Hendron, Kathryn and Sloot, Lizeth H. and Kudzia, Pawel and Stephen Allen and Kenneth G. Holt and Terry D. Ellis and Walsh, Conor J.} } @article {awad2017reducing, title = {Reducing Circumduction and Hip Hiking During Hemiparetic Walking Through Targeted Assistance of the Paretic Limb Using a Soft Robotic Exosuit.}, journal = {American Journal of Physical Medicine \& Rehabilitation}, year = {2017}, publisher = {LWW}, abstract = { ObjectiveThe aim of the study was to evaluate the effects on common poststroke gait compensations of a soft wearable robot (exosuit) designed to assist the paretic limb during hemiparetic walking. DesignA single-session study of eight individuals in the chronic phase of stroke recovery was conducted. Two testing conditions were compared: walking with the exosuit powered versus walking with the exosuit unpowered. Each condition was 8 minutes in duration. ResultsCompared with walking with the exosuit unpowered, walking with the exosuit powered resulted in reductions in hip hiking (27 [6\%], P = 0.004) and circumduction (20 [5\%], P = 0.004). A relationship between changes in knee flexion and changes in hip hiking was observed (Pearson r = -0.913, P \< 0.001). Similarly, multivariate regression revealed that changes in knee flexion (β = -0.912, P = 0.007), but not ankle dorsiflexion (β = -0.194, P = 0.341), independently predicted changes in hip hiking (R2= 0.87, F(2, 4) = 13.48, P = 0.017). ConclusionsExosuit assistance of the paretic limb during walking produces immediate changes in the kinematic strategy used to advance the paretic limb. Future work is necessary to determine how exosuit-induced reductions in paretic hip hiking and circumduction during gait training could be leveraged to facilitate more normal walking behavior during unassisted walking. }, url = {https://doi.org/10.1097/PHM.0000000000000800}, author = {Louis N. Awad and Jaehyun Bae and Kudzia, Pawel and Long, Andrew and Hendron, Kathryn and Kenneth G. Holt and Kathleen O{\textquoteright}Donnell and Terry D. Ellis and Conor J Walsh} } @article {ADMT:ADMT201700135, title = {An Additive Millimeter-Scale Fabrication Method for Soft Biocompatible Actuators and Sensors}, journal = {Advanced Materials Technologies}, year = {2017}, abstract = {A hybrid manufacturing paradigm is introduced that combines pop-up book microelectromechanical systems (MEMS) manufacturing with soft-lithographic techniques to produce millimeter-scale mechanisms with embedded sensing and user-defined distributed compliance. This method combines accuracy, flexibility in material selection, scalability, and topological complexity with soft, biocompatible materials and microfluidics, paving the way for applications of soft fluid-powered biomedical robotics. This paper proposes two classes of fully soft fluidic microactuators and two integration strategies to demonstrate the hybrid soft pop-up actuators. Fatigue properties, blocked torque, maximum deflection, stiffness, and maximum speed are analyzed and the performance of the hybrid mechanisms is compared to their fully soft counterparts. The manufacturing approach allows integrating capacitive sensing elements in the mechanisms to achieve proprioceptive actuation. Multiple hybrid soft pop-up actuators are combined into a multiarticulated robotic arm that is integrated with current flexible endoscopes to improve distal dexterity and enable tissue retraction in an ex vivo proof of concept experiment.}, keywords = {actuators, advanced manufacturing, sensors, soft robotics, surgical robotics}, issn = {2365-709X}, doi = {10.1002/admt.201700135}, url = {http://dx.doi.org/10.1002/admt.201700135}, author = {Sheila Russo and Ranzani, Tommaso and Walsh, Conor J. and Wood, Robert J.} } @article {1115171, title = {Continuous sweep versus discrete step protocols for studying effects of wearable robot assistance magnitude}, journal = {Journal of NeuroEngineering and Rehabilitation}, volume = {14}, number = {1}, year = {2017}, month = {July 12}, pages = {72}, type = {journal article}, abstract = { BackgroundDifferent groups developed wearable robots for walking assistance, but there is still a need for methods to quickly tune actuation parameters for each robot and population or sometimes even for individual users. Protocols where parameters are held constant for multiple minutes have traditionally been used for evaluating responses to parameter changes such as metabolic rate or walking symmetry. However, these discrete protocols are time-consuming. Recently, protocols have been proposed where a parameter is changed in a continuous way. The aim of the present study was to compare effects of continuously varying assistance magnitude with a soft exosuit against discrete step conditions. MethodsSeven participants walked on a treadmill wearing a soft exosuit that assists plantarflexion and hip flexion. In Continuous-up, peak exosuit ankle moment linearly increased from approximately 0 to 38\% of biological moment over 10 min. Continuous-down was the opposite. In Discrete, participants underwent five periods of 5 min with steady peak moment levels distributed over the same range as Continuous-up and Continuous-down. We calculated metabolic rate for the entire Continuous-up and Continuous-down conditions and the last 2 min of each Discrete force level. We compared kinematics, kinetics and metabolic rate between conditions by curve fitting versus peak moment. ResultsReduction in metabolic rate compared to Powered-off was smaller in Continuous-up than in Continuous-down at most peak moment levels, due to physiological dynamics causing metabolic measurements in Continuous-up and Continuous-down to lag behind the values expected during steady-state testing. When evaluating the average slope of metabolic reduction over the entire peak moment range there was no significant difference between Continuous-down and Discrete. Attempting to correct the lag in metabolics by taking the average of Continuous-up and Continuous-down removed all significant differences versus Discrete. For kinematic and kinetic parameters, there were no differences between all conditions. ConclusionsThe finding that there were no differences in biomechanical parameters between all conditions suggests that biomechanical parameters can be recorded with the shortest protocol condition (i.e. single Continuous directions). The shorter time and higher resolution data of continuous sweep protocols hold promise for the future study of human interaction with wearable robots. }, isbn = {1743-0003}, doi = {10.1186/s12984-017-0278-2}, url = {http://dx.doi.org/10.1186/s12984-017-0278-2}, author = {Philippe Malcolm and Rossi, Denise Martineli and Christopher Siviy and Lee, Sangjun and Quinlivan, Brendan Thomas and Martin Grimmer and Walsh, Conor J.} } @article {1113941, title = {Batch Fabrication of Customizable Silicone-Textile Composite Capacitive Strain Sensors for Human Motion Tracking}, journal = {Advanced Materials Technologies}, year = {2017}, abstract = {This paper presents design and batch manufacturing of a highly stretchable textile-silicone capacitive sensor to be used in human articulation detection, soft robotics, and exoskeletons. The proposed sensor is made of conductive knit fabric as electrode and silicone elastomer as dielectric. The batch manufacturing technology enables production of large sensor mat and arbitrary shaping of sensors, which is precisely achieved via laser cutting of the sensor mat. Individual capacitive sensors exhibit high linearity, low hysteresis, and a gauge factor of 1.23. Compliant, low-profile, and robust electrical connections are established by fusing filaments of micro coaxial cable to conductive fabric electrodes of the sensor with thermoplastic film. The capacitive sensors are integrated on a reconstructed glove for monitoring finger motions.}, url = {http://doi.org/10.1002/admt.201700136}, author = {Asli Atalay and Vanessa Sanchez and Ozgur Atalay and Daniel M. Vogt and Florian Haufe and Wood, Robert J. and Walsh, Conor J.} } @proceedings {1113166, title = {Soft Wearable Robots Can Increase Walking Speed and Distance After Stroke: Proof of Concept}, journal = {Combined Sections Meeting of the American Physical Therapy Association (APTA CSM)}, year = {2017}, address = {San Antonio, TX, USA, February 15-18}, author = {Louis N. Awad and Jaehyun Bae and Kathleen O{\textquoteright}Donnell and Kathryn L. Hendron and Kudzia, Pawel and Zurawski, Erica and Kenneth G. Holt and Terry Ellis and Walsh, Conor J.} } @article {1113161, title = {Varying negative work assistance at the ankle with a soft exosuit during loaded walking}, journal = {Journal of NeuroEngineering and Rehabilitation}, volume = {14}, number = {1}, year = {2017}, month = {June 26}, pages = {62}, type = {journal article}, abstract = { BackgroundOnly very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some studies obtained this result by means of high positive work assistance while others combined negative and positive work assistance. There is no consensus about the isolated contribution of negative work assistance. Therefore, the aim of the present study is to examine the effect of varying negative work assistance at the ankle joint while maintaining a fixed level of positive work assistance with a multi-articular soft exosuit. MethodsWe tested eight participants during walking at 1.5 ms-1 with a 23-kg backpack. Participants wore a version of the exosuit that assisted plantarflexion via Bowden cables tethered to an off-board actuation platform. In four active conditions we provided different rates of exosuit bilateral ankle negative work assistance ranging from 0.015 to 0.037 W kg-1 and a fixed rate of positive work assistance of 0.19 W kg-1. ResultsAll active conditions significantly reduced metabolic rate by 11 to 15\% compared to a reference condition, where the participants wore the exosuit but no assistance was provided. We found no significant effect of negative work assistance. However, there was a trend (p = .08) toward greater reduction in metabolic rate with increasing negative work assistance, which could be explained by observed reductions in biological ankle and hip joint power and moment. ConclusionsThe non-significant trend of increasing negative work assistance with increasing reductions in metabolic rate motivates the value in further studies on the relative effects of negative and positive work assistance. There may be benefit in varying negative work over a greater range or in isolation from positive work assistance. }, isbn = {1743-0003}, doi = {10.1186/s12984-017-0267-5}, url = {http://dx.doi.org/10.1186/s12984-017-0267-5}, author = {Philippe Malcolm and Lee, Sangjun and Simona Crea and Christopher Siviy and Saucedo, Fabricio and Ignacio Galiana and Panizzolo, Fausto A. and Kenneth G. Holt and Walsh, Conor J.} } @conference {1113156, title = {Hybrid carbon fiber-textile compliant force sensors for high-load sensing in soft exosuits}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)}, year = {2017}, address = {Vancouver, BC, Canada, September 24-28}, author = {Oluwaseun Araromi and Walsh, Conor J. and Wood, Robert J.} } @conference {1113151, title = {Improved assistive profile tracking for walking and jogging soft exosuits with off-board actuation}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)}, year = {2017}, address = {Vancouver, BC, Canada, September 24-28}, author = {Lee, Giuk and Ye Ding and Ignacio B. Galiana and Nikolaos Karavas and Zhou, Y. M. and Walsh, Conor J.} } @conference {1113146, title = {Distal Proprioceptive Sensor for Feedback Control of Modular Roboendoscopic Systems}, booktitle = {IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)}, year = {2017}, address = {Vancouver, BC, Canada, September 24-28}, author = {Joshua B. Gafford and Wood, Robert J. and Walsh, Conor J.} } @proceedings {1113141, title = {Wearable Soft Robotic Device Supports the Failing Heart In Vivo}, journal = {The 9th Hamlyn Symposium on Medical Robotics}, year = {2017}, address = {London, June 25-28}, author = {Payne, Christopher J. and Wamala, Isaac and Abah, Colette and Thalhofer, Thomas and Saeed, Mossab and Bautista-Salinas, Daniel and Markus A. Horvath and Nikolay V. Vasilyev and Roche, Ellen T. and Pigula, Frank A. and Walsh, Conor J.} } @proceedings {1113136, title = {Human-Exosuit Interfaces Absorb and Return Energy, Reshaping Exosuit to Human Power Flow}, journal = {41st Annual Meeting of the American Society of Biomechanics (ASB)}, year = {2017}, address = {Boulder, CO, August 8-11}, author = {Matthew B. Yandell and Quinlivan, Brendan T. and Dmitry Popov and Walsh, Conor J. and Karl E. Zelik} } @proceedings {1113131, title = {Effect of slope and speed on kinetics of jogging with a backpack}, journal = {41st Annual Meeting of the American Society of Biomechanics (ASB)}, year = {2017}, address = {Boulder, CO, August 8-11}, author = {Philippe Malcolm and Panizzolo, Fausto A. and Jozefien Speeckaert and Jinsoo Kim and Su, Hao and Lee, Giuk and Ignacio B. Galiana and Kenneth G. Holt and Walsh, Conor J.} } @proceedings {1113126, title = {Effect of powered exosuit training on impulse during gait}, journal = {41st Annual Meeting of the American Society of Biomechanics (ASB)}, year = {2017}, address = {Boulder, CO, August 8-11}, author = {Bowers, W. and Panizzolo, Fausto A. and Nikolaos Karavas and Eckert-Erdheim, Asa and Christopher Siviy and Long, Andrew and LaFiandra, M. and Walsh, Conor J. and Freisinger, G.} } @proceedings {1113121, title = {Unilateral ankle assisting soft robotic exosuit can improve post-stroke gait during overground walking}, journal = {41st Annual Meeting of the American Society of Biomechanics (ASB)}, year = {2017}, address = {Boulder, CO, August 8-11}, author = {Sloot, Lizeth and Hejrati, Babak and Kudzia, Pawel and Jaehyun Bae and Kathryn L. Hendron and Kathleen O{\textquoteright}Donnell and Kenneth G. Holt and Terry D. Ellis and Louis N. Awad and Walsh, Conor J.} } @proceedings {1113116, title = {A uni-lateral soft exosuit for the paretic ankle can reduce gait compensations in patients post-stroke}, journal = {41st Annual Meeting of the American Society of Biomechanics (ASB)}, year = {2017}, address = {Boulder, CO, August 8-11}, author = {Kudzia, Pawel and Jaehyun Bae and Louis N. Awad and Long, Andrew and Sloot, Lizeth and Kathryn L. Hendron and Kenneth G. Holt and Kathleen O{\textquoteright}Donnell and Terry Ellis and Walsh, Conor J.} } @proceedings {1113111, title = {Human-Exosuit Interfaces Absorb and Return Energy, Reshaping Exosuit to Human Power Flow}, journal = {XXVI Congress of the International Society of Biomechanics (ISB)}, year = {2017}, address = {Brisbane, Australia, July 23-27}, author = {Matthew B. Yandell and Quinlivan, Brendan T. and Dmitry Popov and Walsh, Conor J. and Karl E. Zelik} } @article {ADMT:ADMT201700081, title = {A Highly Stretchable Capacitive-Based Strain Sensor Based on Metal Deposition and Laser Rastering}, journal = {Advanced Materials Technologies}, year = {2017}, abstract = {Wearable sensing technology is an emerging area and can be utilized for human motion monitoring, physiology monitoring, and human{\textendash}machine interaction. In this paper, a new manufacturing approach is presented to create highly stretchable and soft capacitance-based strain sensors. This involves a rapid surface modification technique based on direct-write laser rastering to create microstructured surfaces on prestrained elastomeric sheets. Then, to impart conductivity, sputtering technology is utilized to deposit aluminum and silver metal layers on the bottom and top surfaces of the elastomer sheet, creating a soft capacitor. During benchtop characterization of the sensors, this study demonstrates that the fabricated electrodes maintain their electrical conductivity up to the 250\% strain, and the sensor shows a linear and repeatable output up to 85\% strain. Finally, their potential is demonstrated for monitoring human motion and respiration through their integration into a wearable arm sleeve and a thoracic belt, respectively.}, keywords = {capacitive sensors, laser rastering, soft strain sensors, sputtering, surface microtreatment}, issn = {2365-709X}, doi = {10.1002/admt.201700081}, url = {http://doi.org/10.1002/admt.201700081}, author = {Ozgur Atalay and Asli Atalay and Joshua Gafford and Wang, Hongqiang and Wood, Robert and Conor Walsh} } @article {1113086, title = {Reducing the metabolic cost of running with a tethered soft exosuit}, journal = {Science Robotics}, volume = {2}, number = {6}, year = {2017}, month = {2017-05-31 17:52}, pages = {eaan6708}, abstract = {Assisting hip extension with a tethered exosuit and a simulation-optimized force profile reduces metabolic cost of running.}, url = {http://doi.org/10.1126/scirobotics.aan6708}, author = {Lee, Giuk and Jinsoo Kim and Panizzolo, Fausto A. and Zhou, Yu Meng and Baker, Lauren M. and Ignacio Galiana and Philippe Malcolm and Walsh, Conor J.} } @conference {1113046, title = {Design and Preliminary Evaluation of a Multi-Robotic System with Pelvic and Hip Assistance for Pediatric Gait Rehabilitation}, booktitle = {15th IEEE International Conference on Rehabilitation Robotics (ICORR)}, year = {2017}, address = {London, July 17-20}, author = {Park, Evelyn J. and Kang, Jiyeon and Su, Hao and Stegall, Paul and Miranda, Daniel L. and Wen-Hao Hsu and Karabas, Mustafa and Phipps, Nathan and Agrawal, Sunil K. and Goldfield, Eugene C. and Walsh, Conor J.} } @conference {1113036, title = {Soft Robotic Shoulder Support: Design, Characterization, and Preliminary Testing}, booktitle = {15th IEEE International Conference on Rehabilitation Robotics (ICORR)}, year = {2017}, address = {London, July 17-20}, author = {O{\textquoteright}Neill, Ciaran and Phipps, Nathan and Cappello, Leonardo and Paganoni, Sabrina and Walsh, Conor J.} } @article {Yandell2017, title = {Physical interface dynamics alter how robotic exosuits augment human movement: implications for optimizing wearable assistive devices}, journal = {Journal of NeuroEngineering and Rehabilitation}, volume = {14}, number = {1}, year = {2017}, pages = {40}, abstract = { \  BackgroundWearable assistive devices have demonstrated the potential to improve mobility outcomes for individuals with disabilities, and to augment healthy human performance; however, these benefits depend on how effectively power is transmitted from the device to the human user. Quantifying and understanding this power transmission is challenging due to complex human-device interface dynamics that occur as biological tissues and physical interface materials deform and displace under load, absorbing and returning power. MethodsHere we introduce a new methodology for quickly estimating interface power dynamics during movement tasks using common motion capture and force measurements, and then apply this method to quantify how a soft robotic ankle exosuit interacts with and transfers power to the human body during walking. We partition exosuit end-effector power (i.e., power output from the device) into power that augments ankle plantarflexion (termed augmentation power) vs. power that goes into deformation and motion of interface materials and underlying soft tissues (termed interface power). ResultsWe provide empirical evidence of how human-exosuit interfaces absorb and return energy, reshaping exosuit-to-human power flow and resulting in three key consequences: (i) During exosuit loading (as applied forces increased), about 55\% of exosuit end-effector power was absorbed into the interfaces. (ii) However, during subsequent exosuit unloading (as applied forces decreased) most of the absorbed interface power was returned viscoelastically. Consequently, the majority (about 75\%) of exosuit end-effector work over each stride contributed to augmenting ankle plantarflexion. (iii) Ankle augmentation power (and work) was delayed relative to exosuit end-effector power, due to these interface energy absorption and return dynamics. ConclusionsOur findings elucidate the complexities of human-exosuit interface dynamics during transmission of power from assistive devices to the human body, and provide insight into improving the design and control of wearable robots. We conclude that in order to optimize the performance of wearable assistive devices it is important, throughout design and evaluation phases, to account for human-device interface dynamics that affect power transmission and thus human augmentation benefits. \  }, issn = {1743-0003}, doi = {10.1186/s12984-017-0247-9}, url = {http://dx.doi.org/10.1186/s12984-017-0247-9}, author = {Matthew B. Yandell and Quinlivan, Brendan T. and Dmitry Popov and Conor Walsh and Karl E. Zelik} } @article {Horvath2017, title = {An Intracardiac Soft Robotic Device for Augmentation of Blood Ejection from the Failing Right Ventricle}, journal = {Annals of Biomedical Engineering}, year = {2017}, pages = {1-12}, abstract = { We introduce an implantable intracardiac soft robotic right ventricular ejection device (RVED) for dynamic approximation of the right ventricular (RV) free wall and the interventricular septum (IVS) in synchrony with the cardiac cycle to augment blood ejection in right heart failure (RHF). The RVED is designed for safe and effective intracardiac operation and consists of an anchoring system deployed across the IVS, an RV free wall anchor, and a pneumatic artificial muscle linear actuator that spans the RV chamber between the two anchors. Using a ventricular simulator and a custom controller, we characterized ventricular volume ejection, linear approximation against different loads and the effect of varying device actuation periods on volume ejection. The RVED was then tested in vivo in adult pigs (n\ =\ 5). First, we successfully deployed the device into the beating heart under 3D echocardiography guidance (n\ =\ 4). Next, we performed a feasibility study to evaluate the device{\textquoteright}s ability to augment RV ejection in an experimental model of RHF (n\ =\ 1). RVED actuation augmented RV ejection during RHF; while further chronic animal studies will provide details about the efficacy of this support device. These results demonstrate successful design and implementation of the RVED and its deployment into the beating heart. This soft robotic ejection device has potential to serve as a rapidly deployable system for mechanical circulatory assistance in RHF. }, issn = {1573-9686}, doi = {10.1007/s10439-017-1855-z}, url = {http://dx.doi.org/10.1007/s10439-017-1855-z}, author = {Markus A. Horvath and Wamala, Isaac and Rytkin, Eric and Doyle, Elizabeth and Payne, Christopher J. and Thalhofer, Thomas and Berra, Ignacio and Solovyeva, Anna and Saeed, Mossab and Hendren, Sara and Roche, Ellen T. and Pedro J. del Nido and Walsh, Conor J. and Nikolay V. Vasilyev} } @proceedings {1075226, title = {Immuno-regulatory Roles of Cyclic Loading that Promotes Skeletal Muscle Regeneration}, journal = {Biomedical Engineering Society (BMES) Annual Meeting}, year = {2017}, address = {Phoenix, AZ, October 11-14}, author = {Seo, Bo Ri and Payne, Christopher and Kwee, Brian and Walsh, Conor J. and Mooney, David J.} } @article {973646, title = {Assistance magnitude versus metabolic cost reductions for a tethered multiarticular soft exosuit}, journal = {Science Robotics}, volume = {2}, number = {2}, year = {2017}, month = {18 Jan 2017}, pages = {eaah4416}, abstract = {When defining requirements for any wearable robot for walking assistance, it is important to maximize the user{\textquoteright}s metabolic benefit resulting from the exosuit assistance while limiting the metabolic penalty of carrying the system{\textquoteright}s mass. Thus, the aim of this study was to isolate and characterize the relationship between assistance magnitude and the metabolic cost of walking while also examining changes to the wearer{\textquoteright}s underlying gait mechanics. The study was performed with a tethered multiarticular soft exosuit during normal walking, where assistance was directly applied at the ankle joint and indirectly at the hip due to a textile architecture. The exosuit controller was designed such that the delivered torque profile at the ankle joint approximated that of the biological torque during normal walking. Seven participants walked on a treadmill at 1.5 meters per second under one unpowered and four powered conditions, where the peak moment applied at the ankle joint was varied from about 10 to 38\% of biological ankle moment (equivalent to an applied force of 18.7 to 75.0\% of body weight). Results showed that, with increasing exosuit assistance, net metabolic rate continually decreased within the tested range. When maximum assistance was applied, the metabolic rate of walking was reduced by 22.83 {\textpm} 3.17\% relative to the powered-off condition (mean {\textpm} SEM).}, url = {http://robotics.sciencemag.org/cgi/content/full/2/2/eaah4416?ijkey=6qzJ/i1Y5NG9c\&keytype=ref\&siteid=robotics}, author = {Quinlivan, Brendan T. and Lee, Sangjun and Philippe Malcolm and Rossi, Denise Martineli and Martin Grimmer and Christopher Siviy and Nikolaos Karavas and Diana Wagner and Alan Asbeck and Ignacio Galiana and Conor J Walsh} } @article {973621, title = {Automatic design of fiber-reinforced soft actuators for trajectory matching}, journal = {Proceedings of the National Academy of Sciences (PNAS)}, volume = {114}, number = {1}, year = {2017}, month = {3 Jan, 2017}, pages = {51-56}, abstract = {Soft actuators are the components responsible for producing motion in soft robots. Although soft actuators have allowed for a variety of innovative applications, there is a need for design tools that can help to efficiently and systematically design actuators for particular functions. Mathematical modeling of soft actuators is an area that is still in its infancy but has the potential to provide quantitative insights into the response of the actuators. These insights can be used to guide actuator design, thus accelerating the design process. Here, we study fluid-powered fiber-reinforced actuators, because these have previously been shown to be capable of producing a wide range of motions. We present a design strategy that takes a kinematic trajectory as its input and uses analytical modeling based on nonlinear elasticity and optimization to identify the optimal design parameters for an actuator that will follow this trajectory upon pressurization. We experimentally verify our modeling approach, and finally we demonstrate how the strategy works, by designing actuators that replicate the motion of the index finger and thumb.}, url = {http://dx.doi.org/10.1073/pnas.1615140114}, author = {Connolly, Fionnuala and Conor J Walsh and Bertoldi, Katia} } @conference {973671, title = {Deployable stabilization mechanisms for endoscopic procedures}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, year = {2017}, address = {Singapore}, abstract = {Abstract:Flexible endoscopes are still the gold standard in most natural orifice translumenal endoscopic surgery (NOTES) procedures; however their flexibility (necessary for navigating through the GI tract) limits their capabilities in terms of distal manipulation and stability. We propose a deployable endoscopic add-on aimed at locally counteracting forces applied at the tip of an endoscope. We analyze different designs: a fully soft version and two hybrid soft-folded versions. The hybrid designs exploit either an inextensible structure pressurized by a soft actuator or the stiffness provided by the unfolded {\textquotedblleft}magic cube{\textquotedblright} origami structure. We focus on the fabrication and experimental characterization of the proposed structures and present some preliminary designs and integration strategies to mount them on top of current flexible endoscopes.}, url = {https://doi.org/10.1109/ICRA.2017.7989134}, author = {Ranzani, Tommaso and Sheila Russo and Schwab, F. and Conor J Walsh and Wood, Robert J.} } @conference {973676, title = {A high-force, high-stroke distal robotic add-on for endoscopy}, booktitle = {IEEE International Conference on Robotics and Automation (ICRA)}, year = {2017}, address = {Singapore}, abstract = {{\textquoteleft}Snap-On{\textquoteright} robotic modules that can integrate distally with existing commercially-available endoscopic equipment have the potential to provide new capabilities such as enhanced dexterity, bilateral manipulation and feedback sensing with minimal disruption of the current clinical workflow. However, the desire for fully-distal integration of sensors and actuators and the resulting form factor requirements preclude the use of many off-the-shelf actuators capable of generating the relevant strokes and forces required to interact with tools and tissue. In this work, we investigate the use of millimeter-scale, optimally-packed helical shape memory alloy (SMA) actuators in an antagonistic configuration to provide distal actuation without the need for a continuous mechanical coupling to proximal, off-board actuation packages to realize a truly plug-and-play solution. Using phenomenological modeling, we design and fabricate antagonistic helical SMA pairs and implement them in an at-scale roboendoscopic module to generate strokes and forces necessary for deflecting tools passed through the endoscope working port, thereby providing a controllable robotic {\textquoteleft}wrist{\textquoteright} inside the body to otherwise passive flexible tools. Bandwidth is drastically improved through the integration of targeted fluid cooling. The integrated system can generate maximum lateral forces of 10N and demonstrates an additional 96 degrees of distal angulation, expanding the reachable workspace of tools passed through a standard endoscope.}, url = {https://doi.org/10.1109/ICRA.2017.7989133}, author = {Joshua B. Gafford and Wood, Robert J. and Conor J Walsh} } @article {973631, title = {Interaction Forces of Soft Fiber Reinforced Bending Actuators}, journal = {IEEE/ASME Transactions on Mechatronics}, volume = {22}, number = {2}, year = {2017}, month = {12 Dec}, pages = {717-727}, abstract = { Soft bending actuators are inherently compliant, compact, and lightweight. They are preferable candidates over rigid actuators for robotic applications ranging from physical human interaction to delicate object manipulation. However, characterizing and predicting their behaviors are challenging due to the material nonlinearities and the complex motions they can produce. This paper investigates a soft bending actuator design that uses a single air chamber and fiber reinforcements. Additionally, the actuator design incorporates a sensing layer to enable real-time bending angle measurement for analysis and control. In order to study the bending and force exertion characteristics when interacting with the environment, a quasistatic analytical model is developed based on the bending moments generated from the applied internal pressure and stretches of the soft materials. Comparatively, a finite-element method model is created for the same actuator design. Both the analytical model and the finite-element model are used in the fiber reinforcement analysis and the validation experiments with fabricated actuators. The experimental results demonstrate that the analytical model captures the relationships of supplied air pressure, actuator bending angle, and interaction force at the actuator tip. Moreover, it is shown that an off-the-shelf bend angle sensor integrated to the actuator in this study could provide real-time force estimation, thus eliminating the need for a force sensor. }, url = {http://dx.doi.org/10.1109/TMECH.2016.2638468}, author = {Wang, Zheng and Panagiotis Polygerinos and Overvelde, Johannes TB and Galloway, Kevin C. and Bertoldi, Katia and Conor J Walsh} } @article {973641, title = {Soft robotic sleeve supports heart function}, journal = {Science Translational Medicine}, volume = {9}, number = {373}, year = {2017}, month = {18 Jan 2017}, abstract = { There is much interest in form-fitting, low-modulus, implantable devices or soft robots that can mimic or assist in complex biological functions such as the contraction of heart muscle. We present a soft robotic sleeve that is implanted around the heart and actively compresses and twists to act as a cardiac ventricular assist device. The sleeve does not contact blood, obviating the need for anticoagulation therapy or blood thinners, and reduces complications with current ventricular assist devices, such as clotting and infection. Our approach used a biologically inspired design to orient individual contracting elements or actuators in a layered helical and circumferential fashion, mimicking the orientation of the outer two muscle layers of the mammalian heart. The resulting implantable soft robot mimicked the form and function of the native heart, with a stiffness value of the same order of magnitude as that of the heart tissue. We demonstrated feasibility of this soft sleeve device for supporting heart function in a porcine model of acute heart failure. The soft robotic sleeve can be customized to patient-specific needs and may have the potential to act as a bridge to transplant for patients with heart failure. }, url = {http://stm.sciencemag.org/cgi/content/full/9/373/eaaf3925?ijkey=hVQqZatzU8EIM\&keytype=ref\&siteid=scitransmed}, author = {Roche, Ellen T. and Markus A. Horvath and Wamala, Isaac and Alazmani, Ali and Song, Sang-Eun and Whyte, William and Machaidze, Zurab and Payne, Christopher J. and Weaver, James C and Fishbein, Gregory and Kuebler, Joseph and Nikolay V. Vasilyev and Mooney, David J and Frank A Pigula and Conor J Walsh} } @article {973661, title = {The Soft Robotics Toolkit: Strategies for Overcoming Obstacles to the Wide Dissemination of Soft-Robotic Hardware}, journal = {IEEE Robotics and Automation Magazine, Special Issue on Open Source and Widely Disseminated Robot Hardware}, volume = {24}, number = {1}, year = {2017}, month = {2017}, pages = {57-64}, abstract = { The Soft Robotics Toolkit (SRT) is an open-access website containing detailed information about the design, fabrication, and characterization of soft-robotic components and systems (Figure 1). Soft robotics is a growing field of research concerned with the development of electromechanical technology composed of compliant materials or structures. The SRT website hosts design files, multimedia fabrication instructions, and software tutorials submitted by an international community of soft-robotics researchers and designers. In this article, we describe the development of the SRT and some challenges in developing widely disseminated robotic-hardware resources. Our attempts to overcome these challenges in the development of the toolkit are discussed by focusing on strategies that have been used to engage participants ranging from K-12 grade students to robotics research groups. A series of design competitions encouraged people to use and contribute to the toolkit. New fabrication methods requiring only low-cost and accessible materials were developed to lower the entry barriers to soft robotics and instructional materials and outreach activities were used to engage new audiences. We hope that our experiences in developing and scaling the toolkit may serve as guidance for other open robotic-hardware projects. }, url = {http://dx.doi.org/10.1109/MRA.2016.2639067}, author = {Holland, D{\'o}nal P. and Abah, Colette and Velasco Enriquez, Marielena and Maxwell Herman and Gareth J. Bennett and Vela, Emir Augusto and Conor J Walsh} } @article {973626, title = {Toward Medical Devices With Integrated Mechanisms, Sensors, and Actuators Via Printed-Circuit MEMS}, journal = {ASME Journal of Medical Devices}, volume = {11}, number = {1}, year = {2017}, month = {11 Jan}, pages = {011007-011018}, abstract = { Recent advances in medical robotics have initiated a transition from rigid serial manipulators to flexible or continuum robots capable of navigating to confined anatomy within the body. A desire for further procedure minimization is a key accelerator for the development of these flexible systems where the end goal is to provide access to the previously inaccessible anatomical workspaces and enable new minimally invasive surgical (MIS) procedures. While sophisticated navigation and control capabilities have been demonstrated for such systems, existing manufacturing approaches have limited the capabilities of millimeter-scale end-effectors for these flexible systems to date and, to achieve next generation highly functional end-effectors for surgical robots, advanced manufacturing approaches are required. We address this challenge by utilizing a disruptive 2D layer-by-layer precision fabrication process (inspired by printed circuit board manufacturing) that can create functional 3D mechanisms by folding 2D layers of materials which may be structural, flexible, adhesive, or conductive. Such an approach enables actuation, sensing, and circuitry to be directly integrated with the articulating features by selecting the appropriate materials during the layer-by-layer manufacturing process. To demonstrate the efficacy of this technology, we use it to fabricate three modular robotic components at the millimeter-scale: (1) sensors, (2) mechanisms, and (3) actuators. These modules could potentially be implemented into transendoscopic systems, enabling bilateral grasping, retraction and cutting, and could potentially mitigate challenging MIS interventions performed via endoscopy or flexible means. This research lays the ground work for new mechanism, sensor and actuation technologies that can be readily integrated via new millimeter-scale layer-by-layer manufacturing approaches. }, url = {http://doi.org/10.1115/1.4035375}, author = {Joshua B. Gafford and Ranzani, Tommaso and Sheila Russo and Alperen Degirmenci and Samuel B Kesner and Robert D. Howe and Wood, Robert J. and Conor J Walsh} } @article {697846, title = {Biomechanical and Physiological Evaluation of Multi-joint Assistance with Soft Exosuits}, journal = {IEEE Transactions on Neural Systems and Rehabilitation Engineering}, volume = {25}, number = {2}, year = {2017}, month = {28 Jan 2016}, pages = {119 - 130}, abstract = { To understand the effects of soft exosuits on human loaded walking, we developed a reconfigurable multi-joint actuation platform that can provide synchronized forces to the ankle and hip joints. Two different assistive strategies were evaluated on eight subjects walking on a treadmill at a speed of 1.25 m/s with a 23.8 kg backpack: 1) hip extension assistance and 2) multi-joint assistance (hip extension, ankle plantarflexion and hip flexion). Results show that the exosuit introduces minimum changes to kinematics and reduces biological joint moments. A reduction trend in muscular activity was observed for both conditions. On average, the exosuit reduced the metabolic cost of walking by 0.21 {\textpm} 0.04 W/kg and 0.67 {\textpm} 0.09 W/kg for hip extension assistance and multi-joint assistance respectively, which is equivalent to an average metabolic reduction of 4.6\% and 14.6\% demonstrating that soft exosuits can effectively improve human walking efficiency during load carriage without affecting natural walking gait. Moreover, it indicates that actuating multiple joints with soft exosuits provides a significant benefit to muscular activity and metabolic cost compared to actuating single joint. }, url = {http://dx.doi.org/10.1109/TNSRE.2016.2523250}, author = {Ye Ding and Ignacio Galiana and Alan T. Asbeck and De Rossi, Stefano M.M. and Jaehyun Bae and Teles Dos Santos, Thiago R. and De Araujo, Vanessa L. and Lee, Sangjun and Kenneth G. Holt and Conor J Walsh} }