Peter Wolf

ETH Zurich | ETH Zürich · Department of Health Sciences and Technology

After a neurological injury, neurorehabilitation aims to restore sensorimotor function of patients. Technological assessments can provide high-quality data on a patient’s performance and support clinical decision making towards the most appropriate therapy. In this study, the ArmeoPower, a robotic exoskeleton for the upper extremities, was used to...

Purpose: An observational study on therapists was executed as a joint project between the Sensory-Motor Systems Lab, ETH Zurich, and the Swiss Paraplegic Centre, Nottwil. The primary goal was to establish a methodology to reasonably tailor current robotic systems to the therapist's preferences in terms of their interaction strategies with the patie...

Introduction: Children and adolescents with neurological impairments face reduced participation and independence in daily life activities due to walking difficulties. Existing assistive devices often offer insufficient support, potentially leading to wheelchair dependence and limiting physical activity and daily life engagement. Mobile wearable rob...

In this work, we propose a framework enabling upper-limb rehabilitation exoskeletons to mimic the personalised haptic guidance of therapists. Current exoskeletons face acceptability issues as they limit physical interaction between clinicians and patients and offer only predefined levels of support that cannot be tuned during the movements, when ne...

Background: Two player games have been suggested to be more motivating than single-player games when applied to neurorehabilitation. This work aimed to contrast cooperative and competitive forms of therapeutic gaming. Methods: An air hockey computer game was played by twenty dyads of subacute stroke patients who did not know each other beforehand....

Robot-assisted neurorehabilitation requires trajectories between arbitrary poses in the patient's range of motion. Data-driven optimization methods, such as Learning by Demonstration, are well suited to replicate complex multi-joint movements. However, these methods lack individualization to patient-, robot- and exercise-specific constraints. We pr...

Wearable robots show promise in addressing physical and functional deficits in individuals with mobility impairments. However, the process of learning to use these devices can take a long time. In this study, we propose a novel protocol to support the familiarization process with a wearable robot (the Myosuit) and achieve faster walking speeds. The...

Robot-assisted neurorehabilitation requires automated generation of goal positions for reaching tasks in functional movement therapy. In state-of-the-art solutions, these positions are determined by a motivational therapy game either through constraints on the end-effector (2D or 3D games), or individual arm joints (1D games). Consequently, these p...

Independent physiotherapy at home is a crucial element of rehabilitative care for a wide range of conditions as it constitutes a large portion of the overall therapy dose. However, up to 80% of individuals who are prescribed at-home physiotherapy do not consistently adhere to their treatment schedule, resulting in poor treatment outcomes. This is l...

Exoskeleton robots found application in neurorehabilitation, telemanipulation, and power augmentation. The human–robot attachment system of an exoskeleton should transmit all the interaction forces while keeping the anatomical and robotic joint axes aligned. Existing attachment concepts were bounding the performance of modern exoskeletons due to in...

We developed an exoskeleton for neurorehabilitation that covered all relevant degrees of freedom of the human arm while providing enough range of motion, speed, strength, and haptic-rendering function for therapy of severely affected (e.g., mobilization) and mildly affected patients (e.g., strength and speed). The ANYexo 2.0, uniting these capabili...

Robots were introduced in the field of upper-limb neuro-rehabilitation to relieve the therapist from physical labor, and to provide high-intensity therapy to the patient. A variety of control methods were developed that incorporate patients' physiological and biomechanical states to adapt the provided assistance automatically. Higher level states s...

Assistive forces transmitted from wearable robots to the robot’s users are often defined by controllers that rely on the accurate estimation of the human posture. The compliant nature of the human–robot interface can negatively affect the robot’s ability to estimate the posture. In this article, we present a novel algorithm that uses machine learni...

Background Exosuits have been shown to reduce metabolic cost of walking and to increase gait performance when used in clinical environment. Currently, these devices are transitioning to private use to facilitate independent training at home and in the community. However, their acceptance in unsupervised settings remains unclear. Therefore, the aim...

Relative comparison of clinical scores to measure the effectiveness of neuro-rehabilitation therapy is possible through a series of discrete measurements during the rehabilitation period within specifically designed task environments. Robots allow quantitative, continuous measurement of data. Resulting robotic scores are also only comparable within...

Knowledge about the orientation of a representative ankle joint axis is limited to studies of tarsal morphology and of quasistatic movements. The aim of our study was therefore to determine the development of the axis orientation during walking. Intracortical bone pins were used to monitor the kinematics of the talus and tibia of five healthy volun...

The versatile functionality of the human upper limb is owed to the coordinated rotation of the scapula and humerus, a pattern called the scapulohumeral rhythm (SHR). Various medical conditions can alter the SHR, frequently leading to limitations in activities of daily living. However, to date, supporting the SHR in practice is often not feasible. W...

Exoskeletons operate in continuous haptic interaction with a human limb. Thus, this interaction is a key factor to consider during the development of hardware and control policies for these devices. Physics simulations can complement real-world experiments for prototype validation, leading to higher efficiency in hardware and software development i...

Soft wearable robots to assist human movements, such as exosuits, have rapidly gained attention thanks to their compliance, low weight and accessibility. However, force measurement in exosuits still rely on load cells and rigid sensors that are not wearable or unsuitable for applications outside the lab. Soft, stretchable and lightweight sensors th...

Soft wearable robots to assist human movements, such as exosuits, have rapidly gained attention thanks to their compliance, low weight and accessibility. However, force measurement in exosuits still rely on load cells and rigid sensors that are not wearable or unsuitable for applications outside the lab. Soft, stretchable and lightweight sensors th...

Exoskeletons operate in continuous haptic interaction with a human limb. Thus, this interaction is a key factor to consider during the development of hardware and control policies for these devices. Physics simulations can complement real-world experiments for prototype validation, leading to higher efficiency in hardware and software development i...

Effortlessly performing activities of daily living constitutes a cornerstone of our personal independence. Naturally, various forms of upper limb impairments can have a substantial impact on quality of life. We developed the Myoshirt, a textile-based soft wearable robot, or exomuscle, that autonomously follows the user’s movements and thereby assis...

Knowledge about the orientation of the ankle joint axis is limited to studies of tarsal morphology and of quasistatic movements. The aim of our study was therefore to determine the axis during walking. Intracortical bone pins were used to monitor the kinematics of the talus and tibia of five healthy volunteers. The finite helical axis was determine...

Coronavirus disease 2019 (COVID-19) has affected the conditions of work in healthcare institutions and the quality of patient care around the world. Emerging healthcare robotic technology may facilitate and improve the overall quality of life, as well as the diagnostics, rehabilitation, and intervention services. This paper reports the lessons lear...

Soft robotic suits are good candidates both for supporting physical therapy in clinical environments and for improving mobility in outdoor settings. Here, we investigate both modes of use using the Myosuit, a lightweight robotic suit for the lower limbs: (1) we show that it can be safely used to support a supervised physical therapy program, and (2...

High-intensity training (HIT) is known to have deteriorating effects on performance which manifest in various physiological changes such as lowered force production and oxidative capacity. However, the effect of HIT in climbing on finger flexor performance has not been investigated yet. Twenty-one climbers partook in an intervention study with thre...

Background Wearable robots have been shown to improve the efficiency of walking in diverse scenarios. However, it is unclear how much practice is needed to fully adapt to robotic assistance, and which neuromotor processes underly this adaptation. Familiarization strategies for novice users, robotic optimization techniques (e.g. human-in-the-loop),...

Background Scapular dyskinesis, i.e., the deviant mobility or function of the scapula, hampers upper limb function in daily life. A typical sign of scapular dyskinesis is a scapula alata—a protrusion of the shoulder blade during arm elevation. While some reversible causes of scapula alata can be treated with therapy, other, irreversible causes requ...

The use of robots has attracted researchers to design numerous haptic training methods to support motor learning. However, investigations of new methods yielded inconclusive results regarding their effectiveness to enhance learning due to the diversity of tasks, haptic designs, participants skill level, and study protocols. In this review, we devel...

This study investigated how skill level and task complexity influence the calibration of perception-action and particularly how close an individual acts relative to his or her maximal action capabilities. Complexity was manipulated between two (Touch, Grasp) and more than two (Removing, Moving Up) nested affordance conditions. For all conditions, w...

Most wearable robots that assist the gait of workers, soldiers, athletes, and hobbyists are developed towards a vision of outdoor, overground walking. However, so far, these devices have predominantly been tested indoors on laboratory treadmills. It is unclear whether treadmill-based laboratory tests are an accurate representation of overground amb...

Wearable robots are undergoing a disruptive transition, from the rigid machines that populated the science-fiction world in the early eighties to lightweight robotic apparel, hardly distinguishable from our daily clothes. In less than a decade of development, soft robotic suits have achieved important results in human motor assistance and augmentat...

Nested affordances in climbing comprise of multiple sequential actions, encompassing more than isolated reaching and grasping. This study examined the extent to which the perception of (multiple) nested affordances in climbing can be understood relative to body-scaled anthropometrics (arm span) and action-scaled (maximal action capabilities) measur...

The use of robotics in health care has seen a recent rise in interest due to its potential for use during the SARS-CoV-2 pandemic. The transmission rate of COVID-19 has meant that health-care workers are under increasing pressure, risks, and workload to manage the requirements of personal protective equipment, strict disinfection procedures, and th...

Background: Physical activity is a recommended part of treatment for numerous neurological and neuromuscular disorders. Yet, many individuals with limited mobility are not able to meet the recommended activity levels. Lightweight , wearable robots like the Myosuit promise to facilitate functional ambulation and thereby physical activity. However, t...

In rowing, rowers need outdoor and indoor training to develop a proficient technique. Although numerous indoor rowing machines have been proposed, none of the devices can realistically render the haptic, visual, and auditory characteristics of an actual rowing scenario. In our laboratory, we developed a simulator to support rowing training indoors....

To complement the assistance of a wearable robot, users with leg weakness often rely on balance and body-weight support (BWS) through their arms and passive walking aids. A precise quantification of this arm support is crucial to better understand real-world robot dynamics, human-robot interaction, and human user performance.

Passive spring-like structures can store and return energy during cyclic movements and thereby reduce the energetic cost of locomotion. That makes them important components of the human body and wearable assistive devices alike. This study investigates how springs placed anteriorly across the hip joint affect leg joint angles and powers, and leg mu...

Although robot-assisted training is present in various fields such as sports engineering and rehabilitation, provision of training strategies that optimally support individual motor learning remains as a challenge. Literature has shown that guidance strategies are useful for beginners, while skilled trainees should benefit from challenging conditio...

Wearable robots for the legs have been developed for gait rehabilitation training and as assistive devices. Most devices have been rigid exoskeletons designed to substitute the function of users who are completely paralyzed. While effective for this target group, exoskeletons limit their users' contributions to movements. Soft wearable robots have...

In the past few years, several light-weight soft wearable robots, so called exosuits, for upper extremity assistance have been developed. The design of exosuits is often based on a bio-mimetic design approach, mimicking the human biomechanics. However, in the design process, the interactions of movement directions during daily living tasks have not...

Wearable robots for the legs have been developed for gait rehabilitation training and as assistive devices. Most devices have been rigid exoskeletons designed to substitute the function of users who are completely paralyzed. While effective for this target group, exoskeletons limit their users' contributions to movements. Soft wearable robots have...

A multitude of robotic systems have been developed to foster motor learning. Some of these robotic systems featured augmented visual or haptic feedback, which was automatically adjusted to the trainee’s performance. However, selecting the type of feedback to achieve the training goal usually remained up to a human trainer. We automated this feedbac...

Motor learning is assumed to be a partly error driven process. Motor learning studies on simple movements have shown that skilled subjects benefit from training with error amplification. Findings of studies with simple movements do not necessarily transfer to complex sport movements. The goal of this work was to determine the benefit of visual erro...

Background Multiplayer games have emerged as a promising approach to increase the motivation of patients involved in rehabilitation therapy. In this systematic review, we evaluated recent publications in health-related multiplayer games that involved patients with cognitive and/or motor impairments. The aim was to investigate the effect of multipla...

Goal-directed reaching movements in three-dimensions are important for our interaction with the environment. Instrumented setups displaying virtual targets for rehabilitation training of reaching movements often provide limited depth cues, which may affect movements. This work aims to quantify effects of limited depth cues on reaching movements. We...

Objectives: To evaluate the immediate responses to forearm compression of blood lactate concentration, heart rate, perceived exertion and local forearm muscle pain during severe climbing in elite climbers. Method: Seven elite climbers (18 ± 2 years; 164 ± 5 cm; 57.8 ± 5.3 kg) performed 3 × 3 climbing bouts with maximal intensity on a distinct 8 m b...

Cybathlon is an event for people with disabilities to compete against each other by solving everyday tasks with the support of the latest assistance technologies.

Background Goal-directed reaching for real-world objects by humans is enabled through visual depth cues. In virtual environments, the number and quality of available visual depth cues is limited, which may affect reaching performance and quality of reaching movements. Methods We assessed three-dimensional reaching movements in five experimental gr...

Subject average hand path ratio group comparison. The boxes in group color denote median and the 50 coverage intervals. The whiskers indicated ±2.7 standard deviations or 99.3% coverage intervals. Small plus symbols denote the outliers. Horizontal black bars above the boxes denote significant group differences in the Tukey-Kramer post-hoc test; A s...

More detailed information on depth cue implementation and rationale. The supplementary S1 Table was added to give some more detailed information and rationale on the different depth cues from Table 1. (PDF)

Investigator’s study protocol. The supplementary S1 Protocol is the checklist according to which the investigator instructed the subject. Dependent on the subject’s preference, the instruction was given in English or German. (PDF)

Result data container. The supplementary S1 Dataset container (.zip file) contains two Matlab® tables (saved as .mat files). “averageResultsTableFile.mat” contains the outcome data of subject means required for the between group analyses (Fig 3, Fig 4, Table 2, and S1 Fig). “resultsTableFile.mat” contains the outcome data for each individual moveme...

Functional Electrical Stimulation (FES) can elicit muscular contraction and restore motor function in paralyzed limbs. FES is a rehabilitation technique applied to various sensorimotor deficiencies and in different functional situations, e.g. grasping, walking, standing, transfer, cycling and rowing. FES can be combined with mechanical devices. FES...

The following is an interview conducted for IEE Robotics and Automation Magazine (RAM) with Stefan Schrade from Team Varileg, Swiss Federal Institute of Technology (ETH), Z?rich, which placed fifth at Cybathlon 2016

The following is an interview conducted for IEEE Robotics and Automation Magazine (RAM) with Robert Riener, who initiated the Cybathlon.

The articles in this special section present the major events, showcases, and activities that were part of the Cybathlon 2016 event.

Robot-assisted training can be enhanced by using augmented feedback to support trainees during learning. Efficacy of augmented feedback is assumed to be dependent on the trainee's skill level and task characteristics. Thus, selecting the most efficient augmented feedback for individual subjects over the course of training is challenging. We present...

Among the different factors employed in a player-centric design of games, personality has not been well researched. At the same time, rewards are a component that could be better utilized in serious games. While recent research suggests that rewards can be beneficial, the effect of reward contingency on motivation is still unclear. The link between...

Multiplayer environments are thought to increase the training intensity in robot-aided rehabilitation therapy after stroke. We developed a haptic-based environment to investigate the dynamics of two-player training performing time-constrained reaching movements using the ARMin rehabilitation robot. We implemented a challenge level adaptation algori...

The aim of this study was to use bone-anchored markers to determine the bone movement of calcaneal adduction, eversion and tibial rotation in a global coordinate system and to describe the relationship of calcaneal adduction to tibial rotation. Furthermore, the amount of overall intra-foot motion in the transverse plane (metatarsal I relative to ca...

In sports, the provision of augmented feedback is an important means to accelerate learning of new movements. Traditionally, concurrent augmented feedback has been provided verbally or visually. However, more recent studies have shown sonification of data during the movement, i.e. the mapping of a measured variable to parameter of sound, can be ver...

Bone anchored markers using intracortical bone pins are one of the few available methods for analyzing skeletal motion during human gait in-vivo without errors induced by soft tissue artifacts. However, bone anchored markers require local anesthesia and may alter the motor control and motor output during gait. The purpose of this study was to exami...

Basalp, Ekin, Gerig, Nicolas, Marchal-Crespo, Laura, Sigrist, Roland, Riener, Robert and Wolf, Peter. Visual Augmentation

Age-related decline in grey and white brain matter goes together with cognitive depletion. To influence cognitive functioning in elderly, several types of physical exercise and nutritional intervention have been performed. This paper systematically reviews the potential additive and complementary effects of nutrition/nutritional supplements and phy...

Rewards in serious games have had a long and at times contentious history about their effect on intrinsic motivation, with contradictory findings about whether they are detrimental to intrinsic motivation or not. While recent research suggests that rewards can be beneficial, the effect of reward contingency on motivation is still unclear. The link...