The 3A system utilises a 3 axis accelerometer sensors to measure the inclination in two dimensions.

The 3AMG system utilises a 3 axis accelerometer, plus 3 axis magnetometer and 3 axis rate gyro sensors to measure orientation in 3 dimensions.

In each system the sensors are wired to an MPU (Master Processing Unit), which collates the data and transmits it to the Pearl Sensor software (included) running on a Windows PC or laptop. The MPU can be slipped into a pocket or taped to a patient. In the standard system, the MPU is connected to the computer using a USB cable (provided). An alternative is the Wireless MPU, which transmits the information using Bluetooth to the PC/laptop.

The sensors, MPU and cables are supplied in a useful carry box.