At this stage of development, the Saccadometer can be considered as a custom-made experimental device. It is designed and manufactured to meet fully the highest standards of safety demanded for a medical diagnostic device.

Electrical hazard

The system is battery powered and the voltage in the system does not exceed 3V. The optional connection with a computer for downloading data (which would not normally be performed while the device is being worn) is via an electrically isolated 1.5m plastic optical fibre. .The mechanical arrangement of terminal sockets on the Saccadometer control unit makes it impossible to make any electrical connections to the control unit when the sensor is connected to it.

Laser radiation

The stimulus lasers are of the type commonly used in laser pointers, but deliberately under-powered to minimse any possible hazard: their maximum output is 0.3 mW rather than the standard 1mW, and can be further adjusted downward by the user: in practice the lowest setting of 0.09mW is commonly used, as this helps conserve battery charge.

Infra-red irradiance

Calculation and direct measurement establish that the infra-red irradiance does not exceed 0.6 mW/cm2, well below the level accepted as the safe for the eyes (10 mW/cm2). The level of irradiance depends on the output of the infra-red illuminators, and the distance between the source and the illuminated surface, which can vary depending on the anatomical shapes of the nose and the eye cavity. The Saccadometer control system automatically compensates for varying distance by adjusting the intensity of the source. When it is closer to the eye, the intensity is automatically reduced, so that the infra-red irradiance is held constant at the calculated level however close the emitter is to the eye.

Cleaning

The sensor and head-band can cleaned and disinfected using a wipe moistened with alcohol: water should not be used