The efficacy of physiological cost index (PCT) measurement of a subject walking with an Intelligent Prosthesis

The Intelligent Prosthesis may enable lower limb amputees to walk faster th an with conventionally damped prostheses and as a result the physical burde n involved in walking could be expected to be considerably higher. The aim of this study was to investigate whether or not physiological cost index (P CI) is applicable as an indicator for monitoring the amount of exercise loa d involved in walking with an Intelligent Prosthesis. The method used a tre admill and monitored gas exchange, ventilation and heart rate (HR) in 6 uni lateral trans-femoral amputees, ages were between 17 and 34 with an average age of 23.1. The exercise protocol was as follows: for each person speeds at 0.8 times the subjects free level walking speed, 1.0 times, 1.2 times, 1 .4 times and for some 1.6 times were applied. In each case the index, of co rrelation between PCI and oxygen uptake in response to walking speed was ca lculated. A significant correlation was observed between PCI and oxygen upt ake in each case, which indicated a close relationship between cardiopulmon ary factor and energy consumption while walking. These results suggest that PCI is of use as an indicator for ascertaining the amount of exercise load in walking with an Intelligent Prosthesis.