Pedograph is a medical device for measuring the variation of foot pressure at the various points under the sole.
“Diabetic patients usually suffer from lack of nerve sensation, especially in the feet. Therefore, their gait on standing and during walking may deviate from that of a normal person and points of high pressure develop under the feet. However, due to neuropathy they do not feel any pain which would have been felt had the nerve functions were alright. Later, ulcers form at these high pressure points, leading to gangrene and eventual amputation of the leg. A Pedograph revealing the variation of foot pressure at various points under the sole easily delineates such high pressure regions at an early stage so that special shoe insoles can be prepared to spread the pressure away from the hot spots. This way the patient is saved from eventual amputation, from being crippled for the entire life. Again, pressure points and pattern may differ while standing and during walking, usually it is the latter which put the soles on greater burden, and a dynamic pressure measurement during walking has more importance from a clinical point of view.” (https://bibeat.com/product/dynamic-pedograph/)
The main sensor unit (Fig) uses an optical method to create an
image of light intensities proportional to the pressure impressed at
individual points. This sensor unit provides a video image and rest of the work is done by software.
In this software, I have added a tool for measuring foot length from the composite image.
Below is the fundamental portion of the code.