This study investigated the feasibility of the Infrared (IR) sensor-based rollator for detecting the gait intention.
We placed two IR sensors on the rollator center to sense left and right knee joint anterior displacement walking intentions. We attached FSR sensor on rollator handles used for safety on/off system. Developed system was composed of wireless ambulatory measurement module that consists of knee joint anterior displacement and FSR signals with bluetooth device which transfers the measured data to PC and Window application for storing and processing and analyzing received data. And then, fuzzy algorithm is used for determining rollator velocity.
We used two IR sensors for investigating knee joint anterior displacement in order to recognize the gait intention. We also measured leg muscle activities and foot pressure, in order to verify our investigation. We took EMG signals of four leg muscles(rectus femoris, biceps femoris, tibialis anterior, the gastrocnemius muscle), and analyzed them. Foot pressure (forefoot, midfoot, rearfoot, inside, outside) were force and mean pressure. The tilt protocol was given bath tilt(10°) and flat(0°) when 1, 2 and 3km/h walking speeds were. We conducted experiments on twenty young healthy adults and ten old adults. Our findings showed that knee joint anterior displacement increases according to gait slop and velocity. It was similar results of muscle activation and foot pressure We verified knee joint anterior displacement through gait intention of detection of possibility.
We developed algorithm to detect gait intention using knee joint anterior displacement and FSR sensors. We devided into 3 parts of gait intention that is start, stop and changing walking velocity using fuzzy algorithm. Decision of starting gate was measured when the differences of distance is bigger than 5cm between R and L knee joint anterior displacement. The gait stop was determined when the differences is less than 4cm for 7 times. The velocity was changed when the distance difference value is more than ±10cm from the baseline. Results also show that the knee joint anterior displacement was efficient in measurement method on gait intention of detection. Potential use of the algorithms is foressn with old adults.