Dual Nintendo Wii remote controllers can be head mounted to track motion with their integral MEMS accelerometers, infrared sensors, and a snap-on gyroscope (right) for detection of rotation.
Consumer-grade infrared cameras in the Nintendo Wii game controller have enabled motion analytics capable of identifying an important eye disorder. A proof-of-concept demonstration showed that affordable medical-grade systems can be built from consumer-grade infrared sensors and opens the door to ultra-precise instruments that harness the Wii's inexpensive micro-electro-mechanical system (MEMS) accelerometers and gyroscopes.
Today medical diagnostics is often dependent on the precise measurement of body posture, to determine if abnormalities fall into a known pattern. If the diagnosis is accurate enough, known conditions and therapies can be quickly invoked to help patients who otherwise might have to wait until symptoms become so acute that no cure is possible.
Unfortunately, precision diagnostic instrumentation is often expensive and cumbersome, opening an opportunity for MEMS sensors to downsize traditional posture measuring instruments using inexpensive components.
Medical researchers at Seoul National University (Korea) recently demonstrated that the consumer-grade infrared camera in the Nintendo Wii controller could be harnessed to create a medical instrument that could diagnose ocular torticollis--an abnormal twist of turn of the neck that patients with ocular defects adopt in order to adopt to maintain binocular vision.
"Accurate measurement of the angle of the abnormal head position is crucial for evaluating disease progression and determining treatment," said medical professor Jeong-Min Hwang at Seoul National University's College of Medicine.
Two Wii remotes were used to jury-rig a three-dimensional (3D) motion sensor the researchers called an infrared optical head tracker (IOHT). A four light-emitting-diode array was used as an invisible infrared beacon that the Wii infrared camera could use to evaluate the distance and orientation of the patient's head.
"We believe IOHT has the potential to be widely used as a head posture measuring device in clinical practice," said Hwang.
Software analytics performed feature detection and pattern recognition on the Bluetooth data streams from the infrared camera to measure and record the angle of the head in real-time. The results were found to comparable those obtained from an expensive laboratory-grade Cervical Range of Motion (CROM) instrument. Sensor readings from the MEMS accelerometers and gyroscopes could be used to further enhance accuracy and real-time tracking capabilities.
For the future, the team hopes to develop a working prototype of an instrument that could rival the clinical utility of a CROM. More extensive analytics could also enable even more precise readings obtained from the MEMS accelerometer and gyroscopes in the Wii remote.
