A Novel Measurement Device for Volume Management in Lower Limb Amputees: A Technical Note

Many amputees suffer from irritation and wounds as a result of poor residual limb volume management. Reasons contributing to failure to maintain volume properly include peripheral neuropathy, cognitive impairment, and social/cultural issues. Amputees commonly use socks of various thicknesses to account for diurnal limb volume loss. However, data relating to sock compliance is lacking due to an absence of a reliable way to collect usage data. A device was fabricated utilizing wireless RFID and socket-limb interface force detection technology to track sock usage and activity of an amputee. Pilot data was collected through both in-lab and out-of-lab protocols. The collected data showed encouraging results tracking interface force data, however accurate sock data collection was difficult. Suggested solutions include designing a more effective antenna and using the interface force data to detect limb presence to start a tag accumulator algorithm. Clinical applications for the Sock Monitor include intervention through alerting the amputee of a need for a sock change before tissue damage occurs and evidence for prosthetists to justify insurance reimbursement for components and socket replacements. The next step is to use a new prototype with better hardware and firmware to collect real-world usage data from a large group of amputees. A predictive model will be made and implemented to determine if intervention in sock usage improves comfort and limb tissue health.