Waseda Bioinstrumentation System WB-3
(Waseda Bioinstrumentation system No.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. 1. Thanks to its extremely reduced dimensions it can be attached to human body with less physical restriction (for comparison, a commercial system with the same characteristics would be 10 times bigger); 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.

The WB-3 wearable bioinstrumentation system was developed by using 20 Inertial Measurement Units (Fig. 2). The weight of whole system (including cables, suit, battery) is about 1.1kg. The is WB-3 portable bioinstrumentation system capable of measuring the motion of human's arms, legs, head and body. Thanks to the CAN bus interface, moreover, it can be easily expanded to integrate the data coming from other sensors. Two example videos of the upper body motion reconstruction are presented below.