Nintendo Wii remote controllers for head posture measurement: accuracy, validity, and reliability of the infrared optical head tracker.
OBJECTIVE
To evaluate the accuracy, validity, and reliability of a newly developed infrared optical head tracker (IOHT) using Nintendo Wii remote controllers (WiiMote; Nintendo Co. Ltd., Kyoto, Japan) for measurement of the angle of head posture.


METHODS
The IOHT consists of two infrared (IR) receivers (WiiMote) that are fixed to a mechanical frame and connected to a monitoring computer via a Bluetooth communication channel and an IR beacon that consists of four IR light-emitting diodes (LEDs). With the use of the Cervical Range of Motion (CROM; Performance Attainment Associates, St. Paul, MN) as a reference, one- and three-dimensional (1- and 3-D) head postures of 20 normal adult subjects (20-37 years of age; 9 women and 11 men) were recorded with the IOHT.


RESULTS
In comparison with the data from the CROM, the IOHT-derived results showed high consistency. The measurements of 1- and 3-D positions of the human head with the IOHT were very close to those of the CROM. The correlation coefficients of 1- and 3-D positions between the IOHT and the CROM were more than 0.99 and 0.96 (P < 0.05, Pearson's correlation test), respectively. Reliability tests of the IOHT for the normal adult subjects for 1- and 3-D positions of the human head had 95% limits of agreement angles of approximately ±4.5° and ±8.0°, respectively.


CONCLUSIONS
The IOHT showed strong concordance with the CROM and relatively good test-retest reliability, thus proving its validity and reliability as a head-posture-measuring device. Considering its high performance, ease of use, and low cost, the IOHT has the potential to be widely used as a head-posture-measuring device in clinical practice.
Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
Jongshin
J
Kim
Kyoung Won
KW
Nam
Ik Gyu
IG
Jang
Hee Kyung
HK
Yang
Kwang Gi
KG
Kim
Jeong-Min
JM
Hwang
D000328:Adult; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D005260:Female; D006257:Head / Q000502:physiology*; D006801:Humans; D007259:Infrared Rays; D008297:Male; D009068:Movement / Q000502:physiology; D010988:Play and Playthings; D011187:Posture / Q000502:physiology*; D015203:Reproducibility of Results; D018910:Video Games; D055815:Young Adult