COMBINED RESPIRATION AND CARDIAC GATING FOR RADIOTHERAPY USING ELECTRICAL IMPEDANCE TECHNOLOGY

摘要

A gating system uses measurements of electrical impedance of a subject to provide simultaneous gating for respiratory and cardiac motion. The gating is based on the change in bio impedance that occurs across trans-thoracic electrodes during breathing and cardiac motion. These quantities can be measured non-invasively in real time by transmitting a known low-amplitude and low-frequency current and measuring voltage drop across electrodes attached to the thorax. The gating signals may control delivery of radiation by a radiotherapy device or an imaging device.