METHOD AND APPARATUS FOR ESTIMATING THE FLUID CONTENT OF A PART OF THE BODY OF A SUBJECT

摘要

There is provided a method for estimating the volume of fluid in part of the body of a subject, the method comprising obtaining a measurement of the circumference, c, of the part of the body of the subject; obtaining a measurement of the impedance of the part of the body of the subject using electrodes attached across the part of the body of the subject; and estimating the volume of fluid in the part of the body of the subject from the measurement of impedance and the measurement of the circumference c. An apparatus comprising a control unit configured to perform the method is also provided.

主权项

1. A method for estimating the volume of extra-cellular fluid in part of the body of a subject, the method comprising:
obtaining a measurement of the circumference, c, of the chest of the subject; obtaining a measurement of the impedance of the lungs of the subject using electrodes attached across the part of the body of the subject; and estimating the volume of fluid in the part of the body of the subject from the measurement of impedance and the measurement of the circumference c by evaluating:VEXT=(ρEXTA1/2L5/2REXT)2/3where VEXT is the volume of extra-cellular fluid in the lungs, REXT is the component of the measurement, of impedance corresponding to the extra-cellular fluid, A is the area of the section invested by the injected current, ρEXT is the resistivity of the extra-cellular fluid, and L is the straight-line distance between the electrodes in a pair when the electrodes are attached to the subject, wherein the distance L is determined from a distance d between the electrodes across the skin of the subject and the measurement of the circumference c.