Tension-Controlled Active Compression Garment for Treatment of Orthostatic Intolerance

Abstract

Medical compression garments are used to treat lymphatic disorders or conditions of poor venous return (e.g. orthostatic intolerance). Conventional compression garments, namely elastic compression sleeves and inflatable compression systems, may aid in relief of these conditions but are also limited in usability. Fixed levels of compression in elastic materials may induce challenges in donning/doffing, complicating patient compliance [1]. Compression levels in inflatable systems are customizable, but these garments are also bulky and require a tethered inflation source [2]. We are interested in developing easy-to-don/-doff compression garments using shape memory alloy (SMA) coil actuators that contract with heat from an applied current which can be wrapped around the body to apply compressive forces. More specifically, we use a spring coil formation as described by Holschuh et al. [3]. Further developed in the Wearable Technology Lab at the University of Minnesota, our current SMA compression garment (SMA-CG) design improves upon the work of Duvall et al. [4] presented in previous year’s (2017) Design of Medical Devices Conference, representing a year’s evolution in active compression garment design that integrate actuators made with SMA.

Everyday Living Artificial Intelligence Hub

“…The Hub framework allows for the analysis of selfsupplied information (such as information about a user's schedule, habits, and preferences) alongside biometric data collected from OTC wearable devices with the goal of providing interventions into the user's life to help them self-regulate. These interventions are in the form of notifications (reminders to breathe, reminders that a meeting or other scheduled time is coming up), or bindings with devices that operate "In Real Life (IRL)" such as the SmartHugs Garment (Pettys-Baker et al, 2018), a wearable shirt designed to perform compression on dysregulated individuals. Detected stress events are confirmed with the user via the Hub Conversational Agent (Hub CA), which can ask questions about the severity and timing of the stressful event, and confirm whether an intervention is necessary or desirable.…”

Dynamic, Tunable, and Conformal Wearable Compression Using Active Textiles

“…Holschuh and colleagues developed multiple compression devices with integrated low‐spring index SMA springs (ε s > 100%) that could be pulled directly over the body like high‐stretch SMP devices. [ 18,44–46 ] While unit tension capabilities were determined by the density of the aggregated SMA springs (meaning compression capabilities vary by device design), these devices have been shown to accomplish generated unit tension up to 1026 N m −1 (a 111% increase from the inactive unit tension). [ 18 ] As with straight filament devices, compression devices composed of spring geometries require a passive substrate to distribute the force produced by the active material elements across the body surface and provide placement management of those elements across that surface.…”

Development of Smart Textile Materials with Shape Memory Alloys for Application in Protective Clothing

“…The ability of SMAs to change their shape, size, or internal structure under the influence of a particular stimulus is the subject of intensive application research [11]. The works in this area are also associated with their applications in textiles and clothing [5,[12][13][14][15][16][17][18][19][20][21][22][23][24]. For example, the active knits made of SMA wire have a great potential for use as innovative actuators, because these materials thanks to the hierarchically organized structure is able to produce complex three-dimensional actuation motions [25].…”