Broadband frequency domain near infrared spectroscopy for fluid volume status monitoring during hemodialysis (Conference Presentation)

We present a new application of Broadband Frequency Domain Near Infrared Spectroscopy (NIRS): monitoring end stage kidney disease (ESKD) patients undergoing hemodialysis (HD). The custom NIRS system combines frequency domain (FD) and broadband continuous wave (CW) measurements. FD and CW measurements were integrated using model-based analysis to provide broadband absorption and reduced scattering changes using modified Beer-Lambert law, using measured scattering values at baseline. Across six HD subjects a notable decrease in CW spectra was observed, indicating an increase in overall absorption as fluid is removed during HD. Oxyhemoglobin, total hemoglobin, and oxygen saturation trended upwards (p < 0.05).