Perspectives on the comparative benefits of body-powered and myoelectric upper limb prostheses.

Background: Patient access to body-powered and myoelectric upper limb prostheses in the United States is often restricted by a healthcare system that prioritizes prosthesis prescription based on cost and perceived value. Although this system operates on an underlying assumption that design differences between these prostheses leads to relative advantages and disadvantages of each device, there is limited empirical evidence to support this view.

Main Text: This commentary article will review a series of studies conducted by our research team with the goal of differentiating how prosthesis design might impact user performance on a variety of interrelated domains.

A Comparison of Approaches for Segmenting the Reaching and Targeting Motion Primitives in Functional Upper Extremity Reaching Tasks.

There is growing interest in the kinematic analysis of human functional upper extremity movement (FUEM) for applications such as health monitoring and rehabilitation. Deconstructing functional movements into activities, actions, and primitives is a necessary procedure for many of these kinematic analyses. Advances in machine learning have led to progress in human activity and action recognition.

Computer-assisted approaches for measuring, segmenting, and analyzing functional upper extremity movement: a narrative review of the current state, limitations, and future directions.

The analysis of functional upper extremity (UE) movement kinematics has implications across domains such as rehabilitation and evaluating job-related skills. Using movement kinematics to quantify movement quality and skill is a promising area of research but is currently not being used widely due to issues associated with cost and the need for further methodological validation. Recent developments by computationally-oriented research communities have resulted in potentially useful methods for evaluating UE function that may make kinematic analyses easier to perform, generally more accessible, and provide more objective information about movement quality, the importance of which has been highlighted during the COVID-19 pandemic.

A comparison of compensatory movements between body-powered and myoelectric prosthesis users during activities of daily living.

Background: People with upper limb absence use compensatory movements to accommodate lack of motion in the prosthetic hand. The purpose of this study was to determine if the type of prosthesis used (i.e.

First Demonstration of Functional Task Performance Using a Sonomyographic Prosthesis: A Case Study.

Ultrasound-based sensing of muscle deformation, known as sonomyography, has shown promise for accurately classifying the intended hand grasps of individuals with upper limb loss in offline settings. Building upon this previous work, we present the first demonstration of real-time prosthetic hand control using sonomyography to perform functional tasks. An individual with congenital bilateral limb absence was fitted with sockets containing a low-profile ultrasound transducer placed over forearm muscle tissue in the residual limbs.

Classification Performance and Feature Space Characteristics in Individuals With Upper Limb Loss Using Sonomyography.

: Sonomyography, or ultrasound-based sensing of muscle deformation, is an emerging modality for upper limb prosthesis control. Although prior studies have shown that individuals with upper limb loss can achieve successful motion classification with sonomyography, it is important to better understand the time-course over which proficiency develops. In this study, we characterized user performance during their initial and subsequent exposures to sonomyography.

Recommendations for the Successful Implementation of Upper Limb Prosthetic Technology.

Despite the numerous prosthetic hand designs that are commercially available, people with upper limb loss still frequently report dissatisfaction and abandonment. Over the past decade there have been numerous advances in prosthetic design, control, sensation, and device attachment. Each offers the potential to enhance function and satisfaction, but most come at high costs and involve surgical risks.

Differences in quality of movements made with body-powered and myoelectric prostheses during activities of daily living.

Background: Upper limb prostheses likely do not enable movements having the same kinematic characteristics as anatomical limbs. The quality of movements made using body-powered and myoelectric prostheses may further differ based on the availability of sensory feedback and method of terminal device actuation. The purpose of this work was to compare the quality of movements made with body-powered and myoelectric prostheses during activities of daily living.

Sonomyography Combined with Vibrotactile Feedback Enables Precise Target Acquisition Without Visual Feedback.

Upper limb prosthesis users currently lack haptic feedback from their terminal devices, which significantly limits their ability to meaningfully interact with their environment. Users therefore rely heavily on visual feedback when using terminal devices. Previously, it has been shown that force-related feedback from an end-effector or virtual environment can help the user minimize errors and improve performance.

Characterizing Functional Upper Extremity Movement in Haptic Virtual Environments.

Haptic virtual environments have been used to assess cognitive and fine motor function. For tasks performed in physical environments, upper extremity movement is usually separated into reaching and object manipulation phases using fixed velocity thresholds. However, these thresholds can result in premature segmentation due to additional trajectory adjustments common in virtual environments.

Differential experiences of embodiment between body-powered and myoelectric prosthesis users.

Prosthesis embodiment, the perception of a prosthesis as part of one's body, may be an important component of functional recovery for individuals with upper limb absence. This work determined whether embodiment differs between body-powered and myoelectric prosthesis users. In a sample of nine individuals with transradial limb absence, embodiment was quantified using a survey regarding prosthesis ownership and agency.

Electrophysiological Evidence of Early Cortical Sensitivity to Human Conspecific Mimic Voice as a Distinct Category of Natural Sound.

Purpose From an anthropological perspective of hominin communication, the human auditory system likely evolved to enable special sensitivity to sounds produced by the vocal tracts of human conspecifics whether attended or passively heard. While numerous electrophysiological studies have used stereotypical human-produced verbal (speech voice and singing voice) and nonverbal vocalizations to identify human voice-sensitive responses, controversy remains as to when (and where) processing of acoustic signal attributes characteristic of "human voiceness" per se initiate in the brain. Method To explore this, we used animal vocalizations and human-mimicked versions of those calls ("mimic voice") to examine late auditory evoked potential responses in humans.

Identifying the benefits and risks of emerging integration methods for upper limb prosthetic devices in the United States: an environmental scan.

: Novel connective and control methods between an upper limb prosthetic device and end-user have large potential rewards and risks, making economic evaluation difficult. : We conducted an environmental scan to assess user perspectives on advancements in upper limb prosthetic device integration. The environmental scan consisted of a PubMed literature search, grey literature review, formation of a community advisory board (CAB) and key informant interviews.

Reliability of upper limb movement quality metrics during everyday tasks.

Background: Quantitative assessments of an individual's functional status commonly involve the use of movement quality metrics.

Research Question: The purpose of this work was to quantify the reliability of movement quality metrics in healthy adults during a variety of unconstrained activities of daily living (ADLs).

Methods: Nineteen participants performed six ADLs (lifting a laundry basket, applying deodorant, turning a doorknob, placing a pill in a pillbox, placing a pushpin in a bulletin board, and drinking water from a glass) during two separate sessions.

Reliability of upper limb and trunk joint angles in healthy adults during activities of daily living.

Assessments of upper limb performance should require participants to perform tasks that challenge the limits of their ability. In order to select appropriate tasks, it is important to know which joints are used to perform the movement and how reliably those movements can be measured. The purpose of this work was to quantify the reliability of upper limb and trunk joint angles in healthy adults during common activities of daily living (ADLs).

Factors associated with interest in novel interfaces for upper limb prosthesis control.

Background: Surgically invasive interfaces for upper limb prosthesis control may allow users to operate advanced, multi-articulated devices. Given the potential medical risks of these invasive interfaces, it is important to understand what factors influence an individual's decision to try one.

Methods: We conducted an anonymous online survey of individuals with upper limb loss.

Surveying the interest of individuals with upper limb loss in novel prosthetic control techniques.

Background: Novel techniques for the control of upper limb prostheses may allow users to operate more complex prostheses than those that are currently available. Because many of these techniques are surgically invasive, it is important to understand whether individuals with upper limb loss would accept the associated risks in order to use a prosthesis.

Methods: An online survey of individuals with upper limb loss was conducted.

Implanted electrodes for multi-month EEG.

An implanted electroencephalogram (EEG) recorder would help diagnose infrequent seizure-like events. A proof-of-concept study quantified the electrical characteristics of the electrodes planned for the proposed recorder. The electrodes were implanted in an ovine model for eight weeks.