Investigation of a body

摘要

PCT No. PCT/GB93/02223 Sec. 371 Date May 30, 1995 Sec. 102(e) Date May 30, 1995 PCT Filed Oct. 28, 1993 PCT Pub. No. WO94/09699 PCT Pub. Date May 11, 1994A method of investigation of a body including applying interrogatory electrical signals at different frequencies to the body. First signals are obtained representing first electrical impedance measurements at the different frequencies. Second signals are obtained representing subsequent second electrical impedance measurements at the different frequencies after a change in the internal state of the body. Characteristics of part of the body are selectively determined in response to the first and second signals at the different frequencies. The invention has application in electrical impedance tomography techniques where the different frequency behavior of different parts of the body associated with temporal changes can be used to improve organ resolution and tissue differentiation.