Measuring Physical and Electrical Parameters in Free-Living Subjects: Motivating an Instrument to Characterize Analytes of Clinical Importance in Blood Samples

Significance: A path is described to increase the sensitivity and accuracy of body-worn devices used to monitor patient health. This path supports improved health management. A wavelength-choice algorithm developed at Mayo demonstrates that critical biochemical analytes can be assessed using accurate optical absorption curves over a wide range of wavelengths. Aim: Combine the requirements for monitoring cardio/electrical, movement, activity, gait, tremor, and critical biochemical analytes including hemoglobin makeup in the context of body-worn sensors. Use the data needed to characterize clinically important analytes in blood samples to drive instrument requirements. Approach: Using data and knowledge gained over previously separate research threads, some providing currently usable results from more than eighty years back, determine analyte characteristics needed to design sensitive and accurate multiuse measurement and recording units. Results: Strategies for wavelength selection are detailed. Fine-grained, broad-spectrum measurement of multiple analytes transmission, absorption, and anisotropic scattering are needed. Post-Beer-Lambert, using the propagation of error from small variations, and utility functions that include costs and systemic error sources, improved measurements can be performed. Conclusions: The Mayo Double-Integrating Sphere Spectrophotometer (referred hereafter as MDISS), as described in the companion report arXiv:2212.08763, produces the data necessary for optimal component choice. These data can provide for robust enhancement of the sensitivity, cost, and accuracy of body-worn medical sensors. Keywords: Bio-Analyte, Spectrophotometry, Body-worn monitor, Propagation of error, Double-Integrating Sphere, Mt. Everest medical measurements, O2SAT Please see also arXiv:2212.08763