Description:
The proposed work will investigate a general approach to improving peripheral blood circulation in the lower leg
by augmenting venous blood return.
The general approach is based on
the literature and findings of a recent investigation that assessed the effects of vacuum-assisted suspension
system (VASS) prostheses on blood circulation in dysvascular transtibial
amputees.
Some support was found for the hypothesis that such devices increase blood flow in the residual limb, but there
also were several unexpected outcomes including elevated
transcutaneous oxygen in the residual limb and increased blood flow in the sound limb.
One explanation for the results is that inadequate movement of blood caused stasis, and VASS
helps veins perform their function by applying cyclic external pressures on the skin during ambulationÍž possibly
replacing/augmenting the forces normally exerted by the calf muscle.
This explanation is supported by a study reporting that venous valves, known to be critical components for
returning blood, occur in far greater numbers in the peripheral venous system
than previously known.
Based on this general hypothesis, alternative strategies for more effectively providing such assistance using
external physical pressure were identified and are
the basis for the more specific approaches to be investigated in the proposed work, which is intended to
determine if peripheral circulation can be improved in non-amputee patients
with diabetes or CVI who are at risk of developing ulcers.