Respiration frequency and volume measuring instrument - has electrodes applied to chest to detect varying electrical impedance

摘要

Respiration volume and frequency may be measured without any form of active co-operation by the patient and without restricting his freedom of movement in any way. This makes this system equally suitable for therapy- or sport applications. This is achieved by applying an RF-field to the patients chest and measuring the varying electrical impedance caused by lung inflation. A r.f. field is generated by a generator (2) and ia applied to the chest of a patient (5) by means of electrodes (1) which effectively form a capacitor. A signal is derived from these electrodes due to the varying impedance and may be monitored visually (5,6,7) or orally.