Abstract:
Pain and pressure sensation as parts of somatosensory system provides sense of awareness of joint
position & body orientation in space. Proprioception works like a constant feedback loop where
human beings are very well aware of body position and forces acting on it. Any abnormality in
pressure especially for amputees would result in skin break down, joint disorders and noncompliance of prosthetic limb. In order to avoid problems related to skin & joints along with
psychological satisfaction of patient, pressure mapping is performed with improved device
compliance. Due to unavailability and high cost of MEMS based bubble sensors and TEKSCAN
system, an effective and low-cost solution to problems related to pressure mapping before and
after prosthetic fittings is introduced wherein a device capable of being incorporated within stump
and prosthesis with minimal chances of breakage due to its flexibility is designed. Twelve
pressure tolerant & sensitive areas of stump were marked upon silicon-based stump liner of 3mm
thickness for TTP socket. FSR are attached to those specified areas and a Bluetooth module is
used in PCB to send data through PLX-DAQ into MS-Excel. When a patient wears his/her
prosthesis along with specially designed silicon liner having FSR and bears weight or walk, data
is sent back into excel sheet recording the pressure values from 12 locations of a stump. Then
adjustments can be made in prosthesis on the exact locations that showed increased pressure
values so to eliminate pain and pinch and relieve the patient. Data from 7 patients during standing/
loading response of gait cycle was taken at Rehabilitation department of hospitals and required
adjustments were made in prosthetic socket and alignment by the clinician/prosthetist.
Comparison between means of pressure values before (27N/m2) and after making adjustment in
prosthesis was made which showed improved values of pressure on distal tibia (<17N/m2) Data
from 1 patient was obtained through all phases of his gait cycle and plotted on MS-Excel to find
out exact phase of gait cycle causing more pressure on stump. The results showed significantly
increased values of pressure on sensitive regions of stump during mid-stance phases of gait cycle
(>75N/m2). While during early stance and swing phases the pressure values were significantly low
(<28.7N/m2)
