Evaluation of a Wearable Sensor System Monitoring Posture Changes and Activities for Use in Rehabilitation

Abstract

To evaluate the effectiveness of rehabilitation, physical therapists must assess the posture changes in patients standing-up, walking, etc. Conventional subjective assessment of using direct observation or interviews at rehabilitation centers and of the actual physical condition is difficult, calling for the development of objective measurement of the posture change and activity both at rehabilitation centers, and in the home. One way to do so is to record these using a video camera, but the measurement range is usually limited and not useful in rehabilitation. A wearable system for monitoring angle changes in the trunk, thigh, and calf on the sagittal plane together with walking speed we developed earlier, required that the user carry three sensors for the trunk, thigh, and calf and a data logger, and wear cumbersome cables. To eliminate this practical drawback, we designed a new sensor for rehabilitation and quantitatively assessed posture change during rehabilitation and activity in daily living using the new system. We combined the previous four units into two – a jacket-typed trunk unit holding a data logger and a sensor for measuring trunk angle change and a knee-supporter-typed lower limb sensors containing two angular sensors – greatly simplifying the cumbersome cable assembly. We measured activity in eight rehabilitation subjects and four subjects during daily living using the wearable device. Results demonstrated that our device could measured detailed motion characteristics as angle changes between body segments during rehabilitation, and the rate of four activities – standing, walking, sitting, and lying – during daily living, making it useful in rehabilitation.

Development of a ubiquitous healthcare monitoring system combined with non-conscious and ambulatory physiological measurements and its application to medical care

“…On the other hand, using the wearable sensor units which 3 axes accelerometer and gyro-sensor, amplifier, Micro SD card, transmitter, battery, CPU are installed, the posture changes and walking speed can be measured with sampling frequency of 25 Hz [15]. The system can record the activities for about 6 hours with real time monitoring using the wireless system and for about 12 hours with off-line monitoring using only memory card.…”

“…Moreover, we attempted to monitor the vital signs in the subject with chronic diseases at the hospital room [14]. Within the ambulatory measurements, we developed a wearable system measuring the detailed postural changes together with walking speed, showing its usefulness for the gerontology and the rehabilitation field [15].…”

Development of a network system combined with ambulatory and non-conscious physiological measurements for supporting challenged kids -A new proposal of a gait monitoring system for use in rehabilitation

“…From these viewpoints, various less-burdensome physiological measurement techniques and network systems were designed [1]- [10]. Also, we developed an ambulatory system measuring the detailed postural changes together with walking speed [11] and non-conscious measurement systems without the need either to attach any biological sensors to the subject's body and any troublesome operations of measurement devices during normal daily life [12]. These showed their high measurement precision by comparison with simultaneous recordings of conventional methods and their usefulness for the medical care and the rehabilitation field [13], [14].…”

“…We are naming this system "Challenged-Kid's Information Delivery Service Note, c-KIDS Note". Especially in this study, using the wearable gait monitoring system [11], [13], newly combined with network, we have firstly investigated its capability to evaluation for the efficacy of the brace attached to the lower limb during rehabilitation program in five children with disabilities. Figure 1 shows the new concept of the network system combined with the ambulatory and the non-conscious physiological measurements for supporting disabled child.…”

“…To achieve the concept mentioned above, we firstly attempted the gait monitoring of the challenged kids in a rehabilitation room using the wearable system as shown in Figure 2. In this study, the sensor units are smaller than those of previous system [11] and in addition the data accumulated in the sensor units can be taken out using a smartphone and a tablet PC by the Bluetooth and be transferred to the data server. By these improvements, the therapist could measure the gait of the children and browse the data without cumbersome operation.…”