HyPSTR: Hydraulic Plantar Soft Tissue Reducer
During 2010 to early 2012, I completed a Master of Science in Mechanical Engineering at the University of Washington. My thesis project consisted of the ideation, design, build, test, and live-human subject testing of the HyPSTR. Data from the testing were used to derive an equivalent stiffness modulus for the test subject's foot bottom.
Although people with diabetes account for only 9% of the population, they undergo ~60% of all lower-limb amputations. Diabetes is thought to stiffen the fat tissue over time, which leads to higher stresses on the bottom of the foot causing ulcers that frequently lead to amputation.
The design, build, and test of the device was documented in my thesis and a journal article (ARTICLE 1) written by the grad student who took over the project after my graduation. The data obtained with the device were used (after my graduation) as input to a subject-specific, whole-foot finite element model from which internal stresses in the soft tissue were quantified (ARTICLE 2).
System schematic
System (LHS is in Control room, RHS is in MR Imaging room)
Lower leg constraint (reflects some updates made after I left)
Data signal filter design and EMI-based noise reduction results
1-pixel width of MRI data from patient A high-resolution scan
1-pixel width of MRI data from patient A dynamic scan showing heel soft tissue compression
Patient A heel soft tissue stiffness modulus derivation
