Final Design

The final device consists of two main parts: the garment and the electronics. The garment, shown in Figure 10c and 10d, includes vacuum ports, Velcro flaps, and a bladder sewn into a pocket. The electronics include a peristaltic pump, a pressure sensor, and a User Interface (UI) contained within a housing, connected to the garment via a silicone tube running from the pump to the bladder.

The garment is made from three fabrics: YULEX, Ripstop, and spandex. YULEX is used for structure and comfort, as it is a sturdy yet soft closed cell foam material. It is sewn between two layer of Ripstop, chosen for its inelasticity and waterproof nature, the former of which allows it to fully translate the expansion of the bladder into constriction around the leg, and the latter of which allows the garment to be easily wiped down and cleaned when a patient visits for a check-up. Spandex was used for the bladder pocket alone, as a stretchy material was required to allow the bladder to expand as much as possible without resistance. The bladder was made from Thermoplastic Polyurethane (TPU) and the fastening method was chosen to be Velcro, for ease of application and adjustability. Two vertical rows of portals were placed 180 degrees apart on the garment for NPWT tubing to be routed through.

The bladder is connected to the electronics housing by a length of silicone tubing, where it is inflated by a peristaltic pump to a bladder pressure that correlates to the prescribed garment pressure. Pressure sensors and feedback control ensure accurate garment pressure is applied. A user interface enables medical professionals to set and monitor garment pressure. The system is powered by a rechargeable lithium battery that is to be charged while the patient sleeps at night by a wall charger.

Though this non-waterproof garment is the final design solution, a garment with waterproofing aspects was also made. As shown in the sketch in Figure 8 and the photos of the actual garment shown in Figure 9a, 9b, and 9c, this prototype includes nitrile gaskets on the top and bottom of the garment, as well as on each vacuum port to ensure waterproofing.