A radio receiver includes a low noise amplifier, intermediate frequency mixing stage, complex bandpass filter, a single analog to digital converter, a 1st digital mixing module, and a 2nd digital mixing module. A branch node includes a search key sequence number expressing the position information of a key in the search key string to be used in the bit string comparison during the bit string search and the discrimination bit position for that key. The system corroborates, patient, the care provider, the medical device, and the manner in which it is to be used, and authorizes the action to be undertaken through an interface on a personal digital assistant PDA over a wireless communication channel. The detection level of the natural emission light by the semiconductor light detecting element decreases, and light detection precision increases. A switch may be provided to operate the system upon trigger actuation, or independently of the firearm trigger. Thus the device and a vehicle lamp comprising the device can prevent light energy from losing.