Clinical trials

Major depressive disorder (MDD) is a serious condition that causes long-term symptoms such as feeling sad, losing interest in activities, and having thoughts of self-harm. Difficulty in making an effort is a key factor in functional impairment. Current methods to evaluate this difficulty use clinical assessments and computer-based tasks, but there is a gap between the measurements and real-life behavior. To address this, the study team proposes creating an instrumented behavioral test, HORMES, to objectively assess reduced motivation during everyday activities and measure physiological responses. The study will examine differences in brain activity, autonomic system function, and metabolic energy expenditure in patients with major depression during a decision-making task that involves physical effort.

The goal of this study is to learn about the effect of applying transcutaneous vagus nerve stimulation (tVNS) during motor training on motor learning in older adults. The main question it aims to answer is whether applying tVNS after successful motor trials (post-success tVNS) will facilitate the rate of motor learning. Participants will be randomly assigned to tVNS or sham group and receive tVNS or sham, respectively, at the outer ear during finger control training sessions. Finger control performance will be tested before and after the training sessions without outer ear stimulation.

Two hallmarks of both healthy aging and age-related disease are 1) memory and navigational deficits, particularly in orienting towards goal locations and planning how to navigate to them, and 2) increased susceptibility to stress and altered regulation of the stress response. However, there are marked individual differences in these age-related changes. The investigators' proposal will help characterize factors that contribute to this variability. Participants will be pseudorandomly assigned to stress-manipulated or control groups. The investigators will give both groups a novel immersive navigation task, validated by the PI in healthy young adults. This paradigm gives participants the opportunity to either (a) flexibly draw on spatial memory in order to plan efficient routes to goal locations, or (b) fall back on inefficient, but cognitively less-demanding, stimulus-response associations (i.e., habits). Using neuroimaging and behavioral measures, the investigators' protocol will test whether experimentally-induced stress leads individuals to bring fewer details about future locations to mind when route planning, and whether such restricted prospective thought ultimately biases participants towards relatively inflexible, habitual actions.

This work will focus on new algorithms for robotic ankle exoskeletons and testing these in human subject tests. Individuals who have previously had a stroke will walk while wearing a robotic exoskeleton on a specialized treadmill as well as during other movement tasks (e.g., overground, stairs, ramps). The study will compare the performance of the advanced algorithm with not using the device to determine the clinical benefit.

An exoskeleton device is a robotic system designed to improve an individual's ability to move and perform tasks encountered in everyday situations. These devices consist of external rigid limb segments that assists humans through different body movements with the use of actuators. These devices are controlled by an onboard computer that determines the timing and magnitude of assistance deployed to the user. Exoskeleton controller performance is key to providing beneficial assistance that does not inhibit the user's movement. Preceding work will compare the benefit of personalized hip versus ankle joint exoskeleton assistance for improvement of post-stroke gait. It will combine exoskeleton technology with the user's movement feedback to improve wearable robotic assistance to an individual stroke survivor's gait pattern. For the clinical trial research covered under this protocol, the investigator will test various exoskeleton technologies with stroke survivors in real-world contexts, indoors and outdoors, and measure clinically meaningful outcomes and user perceptions regarding technology usability and adoption. The long-term goal is to deploy self-adaptive, adoptable exoskeletons for personalized assistance during community ambulation.

Conduct a clinical field trial at CHOA's Day Rehab Program using the clinical exoskeleton in conjunction with visual biofeedback with pediatric patients who present with genu recurvatum or crouch gait over 5 rehabilitation visits.