TY - JOUR
T1 - Measurement of posture by triangulation using potentiometers
AU - Yu, C. H.
AU - De, N.
PY - 1999/5
Y1 - 1999/5
N2 - To measure the posture of a paraplegic while standing up, an economical method has been developed. Markers, glued over the joints, hook onto strings which run to rotary potentiometers mounted on a fixed frame. Springs maintain a near-constant small tension in the strings, and the potentiometers rotate as the strings wind onto pulleys. The positions are calculated by triangulation, using two potentiometers per joint, assuming that body segment lengths are constant, or three potentiometers without this assumption. Using a second-order polynomial fit, the random error in length measurement for each potentiometer is less than ±2 mm for the string length from 0 mm to 1100 mm, or less than ±1 mm in actual range from 600 mm to 1000 mm. With two potentiometers per joint, using a second-order polynomial fit and assuming the ankle position is known exactly, an estimate of the resulting errors in the knee and hip marker positions are 4 and 8.5 mm, respectively.
AB - To measure the posture of a paraplegic while standing up, an economical method has been developed. Markers, glued over the joints, hook onto strings which run to rotary potentiometers mounted on a fixed frame. Springs maintain a near-constant small tension in the strings, and the potentiometers rotate as the strings wind onto pulleys. The positions are calculated by triangulation, using two potentiometers per joint, assuming that body segment lengths are constant, or three potentiometers without this assumption. Using a second-order polynomial fit, the random error in length measurement for each potentiometer is less than ±2 mm for the string length from 0 mm to 1100 mm, or less than ±1 mm in actual range from 600 mm to 1000 mm. With two potentiometers per joint, using a second-order polynomial fit and assuming the ankle position is known exactly, an estimate of the resulting errors in the knee and hip marker positions are 4 and 8.5 mm, respectively.
KW - FES
KW - Joint position measurement
KW - Posture measurement
UR - http://www.scopus.com/inward/record.url?scp=0033134162&partnerID=8YFLogxK
U2 - 10.1016/S1350-4533(99)00045-4
DO - 10.1016/S1350-4533(99)00045-4
M3 - Article
C2 - 10514044
AN - SCOPUS:0033134162
SN - 1350-4533
VL - 21
SP - 259
EP - 263
JO - Medical Engineering and Physics
JF - Medical Engineering and Physics
IS - 4
ER -