A non-invasive and portable bioimpedance method and a device for detecting superior to inferior closure of the pharynx during swallowing have been developed. The 2-channel device measures electric impedance across the neck at two levels of the pharynx via injected currents at 40 and 70 kHz. The device has been trialled on both healthy and dysphagic subjects. Results from these trials revealed a relationship (r = 0.59) between the temporal separation of the second peaks in the bioimpedance waveforms and descending pressure sequence in the pharynx as measured by pharyngeal manometry. However, these features were only clearly visible in the bioimpedance waveforms for 64% of swallows. Further research is underway to improve the bioimpedance measurement reliability and validate waveform feature correlation to swallowing to maximise the device's efficacy in dysphagia rehabilitation.
Keywords: 2-channel device; bioelectric phenomena; bioimpedance measurement reliability; bioimpedance waveforms; biomedical measurement; descending pressure sequence; dysphagia rehabilitation; dysphagia visualisation; dysphagic subjects; electric impedance measurement; electrical bioimpedance measurement; frequency 40 kHz; frequency 70 kHz; injected currents; medical disorders; neck; pharyngeal manometry; pharynx closure; portable bioimpedance method; swallowing; waveform feature correlation.