A tele-monitoring system for gait rehabilitation with an inertial measurement unit and a shoe-type ground reaction force sensor

In this paper, a tele-monitoring system is proposed, using an inertial measurement unit (IMU) and a shoe-type ground reaction force (GRF) sensor called a Smart Shoe to measure a patient's walking data, and transmitting the measured data via the Internet. In our previous work, a mobile gait-monitoring system was developed, which provided visual feedback based on GRFs measured by a Smart Shoe (used as a mobile platform). However, the limited information provided by the Smart Shoe alone may not be adequate for a tele-monitoring system using the Internet. In the present tele-monitoring system for gait rehabilitation, a Smart Shoe is combined with an IMU for detailed monitoring of walking motions. By analyzing the signals from the IMU and the Smart Shoe, foot trajectories, walking distance, length of stride, etc., can be estimated. A user-friendly graphic interface displays the measured or estimated data on separate computers at the patient's location and the physical therapist's office. Thus, using the proposed system , it is possible to monitor a patient's walking motion via the Internet, without restrictions on time or place. Gait rehabilitation treatment is usually administered manually by a physical therapist in a rehabilitation facility. The physical therapist diagnoses the patient's status based on walking data, and then provides an appropriate gait rehabilitation intervention. Since evaluation of the patient's status from detailed monitoring data is one of the most fundamental aspects of the rehabilitation process, numerous evaluation methods and monitoring systems have been developed. The Fugl-Meyer Assessment [9], Functional Independence Measure (FIM) [11], and Barthel Index [7] have been widely used to evaluate motor and sensory impairment. However, these questionnaire-based methods are difficult to use for observation or assessment of the dynamic motions of daily living, such as walking motions, and monitoring such dynamic motions mainly depends on the experience, knowledge, and observational skills of the physical therapist. The sensor sets required to quantitatively measure and assess dynamic motions are usually complicated, and are applicable only in specially equipped environments, such as research laboratories or hospitals. Also, rehabilitation treatments are administered to patients only when they visit a rehabilitation facility, and thus the rehabilitation effect is experienced only during rehabilitation sessions. Camera-based methods such as VICON [20] are widely used for observing gait motions. These methods require several optical markers to be mounted on the human body, and the light reflected from the markers is detected by cameras. They produce well-quantified and …