Minimum Variance Signal Selection for Aorta Radius Estimation Using Radar

Abstract

This paper studies the optimum signal choice for the estimation of the aortic blood pressure via aorta radius, using a monostatic radar configuration. The method involves developing the Cramér-Rao lower bound (CRLB) for a simplified model. The CRLB for model parameters are compared with simulation results using a grid-based approach for estimation. The CRLBs are within the 99% confidence intervals for all chosen parameter values. The CRLBs show an optimal region within an ellipsoid centered at 1 GHz center frequency and 1.25 GHz bandwidth with axes of 0.5 GHz and 1 GHz, respectively. Calculations show that emitted signal energy to received noise spectral density should exceed 10 12 for a precision of approximately 0.1 mm for a large range of model parameters. This implies a minimum average power of 0.4 μW. These values are based on optimistic assumptions. Reflections, improved propagation model, true receiver noise, and parameter ranges should be considered in a practical implementation.

Ultrawideband Technology in Medicine: A Survey

“…A criterion Journal of Electrical and Computer Engineering 7 for the best selection of bandwidth and center frequency was presented in [16,17]. Even with a more realistic simulation scenario than that in Figure 5, the feasibility of estimating the aorta radius with the use of UWB radar has been demonstrated [18].…”

“…For instance, the IR-UWB radar has the potential to detect, noninvasively, tiny movements inside the human body [14]. Thereby, it is entirely possible to monitor cardiovascular physiological parameters using movement detection of the aorta [15][16][17][18] or other parts of the arterial system. Such parameters include heart rate (HR), respiration motion, blood pressure (BP), and so forth.…”