IR control in operating theatres

If operating theatre equipment, such as OR tables, is adjusted using infrared (IR) controls, this can interfere with lighting control or regulation when combined. Interferences of IR controls in fluorescent lamp operation with electronic control gear (ECG) can occur if the operating frequency or harmonic oscillations thereof in ECG and modulation frequencies of IR controls are too close to each other, frequency filter edges are not steep enough, meaning the interference distance is too low, or where frequency ranges even overlap.

These issues can be avoided by observing the criteria for IR emitters and receivers as well as typical operating frequencies for IR controls in operating theatres (see also table) defined by European standard EN 61920 "Infrared free air applications" (2004 edition). In case of doubt, preliminary testing for correct functioning of IR controls is recommended (q.v. chapter "IR control compatibility").

Table 1.93: Examples for operating frequencies of IR controls in the operating theatre as well as electronic control gear (ECG)

With LED luminaires this problem will not occur. LED light does neither show any IR radiation nor the critical opration frequency range to disturb an IR receiver.