Figure 4. Neck-worn positional therapy device.

The middle part (ring structure) of the apparatus shown consists of a small vibrating motor (such as the one used in cell phones) and a position sensor. Three small round batteries (two positioned on the left, one on the right) are connected via the white cables. The braided black cables connect the device to the polysomnograph system. Reprinted from Journal of Sleep Research, Vol 21(3), van Maanen JP et al. Evaluation of a new simple treatment for positional sleep apnoea patients, pages 322-329, Copyright 2012, with permission of John Wiley & Sons, Inc.²⁸