Evaluation of swallowing functions depend on aging and surgical operation of gullet cancer using neck bioelectrical impedance

We have confirmed that observation of the neck electrical impedance was effective to evaluate swallowing functions. Consequently, we have proposed Impedance Pharyngography (IPG) which could record the neck electrical impedance during swallowing. However, it is not easy to compare different subject's IPG directly. We introduced the parameter analysis and the discriminant analysis. The parameter analysis can evaluate IPG waveforms quantitatively. And the discriminant analysis can classify swallowing functions into some groups using result of the parameter analysis. First of all, we obtained IPGs of 88 persons classified into the four groups. And we performed the parameter analysis and the discriminant analysis. As a result, we could obtain the hitting ratio of 65.9% and three discriminant functions. Next, we obtained IPGs of one gullet cancer patient. He is not included in abovementioned 88 persons. His IPG waveforms were measured by several times before and after the surgical operation. We analyzed these using the parameter analysis and the discriminant functions obtained by the discriminant analysis of abovementioned 88 persons. These results corresponded with the state of his swallowing functions at that time. By using statistical processing, we obtained the inspection results which can compare a subject's swallowing functions with the other subjects' ones. Consequently, it can be said that the diagnostic value of this method is very useful.