Miniature personal radiation detector - records doses due to radiotherapy and permits location of tumours and blood clots

摘要

Nuclear radiation are measured by a portable instrument which is carried with a patient to record doses due to radiotherapy treatment. It permit doctors to travel to a patient rather than vice versa for the location of tumours and blood clots. Radiations are sensed by a detector (30) whose type depends on application envisaged and is polarised from a DC/DC converter (31) which obtains a high voltage from the instrument battery. The detector output is amplified (32) by an amplifier with FET input and then applied to threshold level (33) and pulse shaping circuits (34). Pulses are counted (36) during period determined by a clock generator (35). The counted pulses are indicated on a numerical display (37) while a loudspeaker (38) connected to a low frequency amplifier (39) gives audible indications.