Question

Read how can you design an impedance plesmythography device that measures changes in electrical resistance across the chest with respiration. Compare it with the pneumatic compression belt-triggering type.

Answer 1

Answer :-

1. Impedance Plethysmography :- It is a method of determining changing tissue volumes in the body, based on the measurement of electric impedance at the body surface. Determination of the cardiac stroke volume is an area in which accurate, easily applied, noninvasive methods are needed. Impedance cardiography is easy to apply, noninvasive, and also cheap; however, it has serious methodological limitations, which are discussed below. We also provide a brief overview of other applications of impedance plethysmography.
The magnetic method corresponding to electric impedance plethysmography is called magnetic susceptibility plethysmography. This method may be used for monitoring blood volume changes in the thorax. Most living tissues are diamagnetic since water is their major constituent. If a strong magnetic field is applied to the region of the thorax, the movements of the heart, blood, and chest wall during the heart cycle cause variations in magnetic flux.

2. Pneumatic Compression Belt :- Pneumatic compression belt is developed for abdominal compression and is used to reduce respiratory motion of patients undergoing hypo-fractionated or single fraction stereotactic radio-ablative therapy for abdominal cancers. The clinical objective of belt usage was to reduce the cranial-caudal (CC) respiratory motion of the tumor to 5 mm or less during both CT simulation and treatment. A retrospective analysis was done to determine the effectiveness of the device and associated clinical procedures to reduce the CC respiratory motion of the tumor.