Session 9: Flexible Electronics Applications I

The Flexible Electronics behind the Graftworx SmartPatch
Wednesday, February 14, 2018
2:35 PM - 2:55 PM

Tremendous opportunity to improve medical care can be facilitated by adapting the Internet of Things (IoT) to the Internet of the Body. Each pathology presents different challenges for wearability, power consumption, sensor selection, sensor interface, and economics. Graftworx is addressing the particular need of monitoring the health of an arteriovenous access used in the hemodialysis of patients suffering end stage renal disease. The access is surgically created in a patient to provide an area of high flow to remove and return blood during hemodialysis. If the access becomes blocked, the success rate of clearing the blocking by techniques such as an angioplasty improves the sooner the blockage can be detected and addressed. Graftworx has designed a wearable SmartPatch that is worn over the arteriovenous access. A suite of sensors is used to monitor the flow through the access. If a disruption to healthy flow is detected, an alert is generated to the clinician. The electronics for the SmartPatch are fabricated on a single substrate flex board that has been fabricated with regions of different stiffness. The flexible tether regions support the bending of the SmartPatch around physiological features. Regions of greater stiffness provide stress isolation and higher reliability for the soldered components during the molding process and also in use. A single substrate flex was chosen instead of a rigid-flex design to minimize the area that would have otherwise been required for interconnects. Challenges of the assembly due to incorporation of specific sensors and a battery are also discussed.