Development of vibrating insoles.

The objective of this study was to describe the development of vibrating insoles. Insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy. This study describes the requirements for the tactors, (tactile actuators) insole material and noise generator. A search for the components of vibrating insoles providing mechanical noise to the plantar side of the feet was performed. The mechanical noise signal should be provided by tactors built in an insole or shoe and should obtain an input signal from a noise generator and an amplifier. Possible tactors are electromechanical tactors, a piezo actuator or the VBW32 skin transducer. The Minirator MR1 of NTI, a portable MP3 player or a custom-made noise generator can provide these tactors with input. The tactors can be built in foam, silicone or cork insoles. In conclusion, a C2 electromechanical tactor, a piezo actuator or the VBW32 skin transducer, activated by a custom-made noise generator, built in a cork insole covered with a leather layer seems the ideal solution.