WB-3R
(Waseda Bioinstrumentation system No.3 Refined)

Research overview

To evaluate objectively the training of medical skill, motion measurement has ever been performed by skill evaluation machine and motion capture system. But, they are unsuitable to stress and psychological stability evaluation because they are considered for subject psychological state. Then, the long-turm vision is to develop the system, which can make the training more efficient by feedback of the result of skill and psychological evaluation from system to trainee or boss. So, we measure both motion and psychological state in the training situation at once. This research purpose is to construct comprehensive measurement system "WB-3R" (Waseda Bioinstrumentation system No.3 Refined), which is added physiological marker for psychological measurement to before motion capture system. In this experiment, we use EMG (electromyography) as physiological marker.

Fig. 1 WB-3R

Fig. 1 WB-3R

TOP

System overview

Before now, we have developed ultra-miniaturized wearable motion capture system, WB-3, which can measure the position and motion of head, arms and hands. In this research, we use ultra-miniaturized wearable motion capture system, WB-3(Waseda Bioinstrumentation system No.3). And we add EMG as physiological marker to WB-3, we construct new comprehensive system, WB-3R, which can measure the position motion and physiological marker at once.

WB-3

WB-3 The WB-3 IMU is very compact and light weight (size 26 x 20 x 8 mm and weight 2.9 g). A picture of the WB-3 IMU is shown in Fig. 2. it can also be easily attached to objects and tools without effecting their overall weight and balance. The IMU is composed by the following sensors : 3-axis accelerometer LIS3LV02DL; 2-axis gyroscope IDG300; 1-axis gyroscope LISY300AL; and 3-axis magnetometer HMC5843. IMU's characteristics are summarized in Table 1. The IMU contains also a 32 bit microcontroller STM32 Cortex (STMicroelectronics) for embedded signal elaboration. The communication between PC and IMU is performed using CAN BUS at 1 Mb/s. Sampling frequency is 100[Hz].


Fig. 1 WB-3 IMU

Fig. 2 WB-3 IMU

Table 1. WB-3 IMU characteristics

Table 1. WB-3 IMU characteristics

TOP

EMG

WB-3R is assumed to medical training and the scene of surgery. There are many physiological marker to measure psychological state. But, some way to measure physiological marker is unsuitable, for example, sweating, which is need to be set on fingertip and Electroencephalogram, which give restraint. Then, we select EMG. Actually, measurement of EMG is performed to measure the muscle state. But, as measuring paticular muscle state, we can make a conjecture of psychological state. Measuring EMG enable to know stress level and impatient level. Then, we can evaluate objectively stress and impatient torelance, and psychological stability. In this research, we use surface EMG sensors (DELSYS Ins. Figure. 3), which enable to measure EMG easily. This EMG sensor's characteristics are summerized in Table 2. In program, WB-3R perform nondimensionalization automatically and output the relative value against max EMG value.



Fig. 3 Surface EMG sensors

Fig. 3 Surface EMG sensors

Table 2. Surface EMG sensors characteristics

Table 2. Surface EMG sensors characteristics

TOP

History

WB-1 (2004)

WB-1R (2005)

 WB-2

WB-2 (2007)

WB-2R (2008)

 WB-3

WB-3 (2009)
Last Update: 2011-11-01
Copyright(C) 2003-2011 WB Team/Takanishi Laboratory
All Rights Reserved.