Statistical Validation of Heart Rate Measurement Using Modulated Magnetic Signature of Blood with Respect to Electrocardiogram

 Abstract—Heart rate (HR) is an important human physiological marker commonly used for the understanding of an individual's physical health. This paper adopts and outlines the magnetic method of non-invasive acquisition of blood pulse using the disturbance created by blood flowing through a localized magnetic field (i.e. Modulated Magnetic Signature of Blood - MMSB). The measurement setup is designed to acquire the MMSB and a gold standard instrumentation, Electrocardiogram (ECG) for 20 healthy subjects (10 males and 10 females, aged 18-22). Two independent measurements were conducted for each subject resulting in 40 HR measurements collected. Four statistical tests were applied to validate the instantaneous HR measured from MMSB waveform with respect to the ECG waveform. First, the Pearson Correlation and Coefficient of Determination was applied on the measured HR and both MMSB and ECG methods of measurements were positively correlated (R=0.99) with perfectly linear relationship (< 1% scores in the data due to error). Secondly, the Paired Student's t-test and the Wilcoxon Signed-Rank Test were applied on the measured HR and they showed no significant difference (at 95% limits of agreement) for the mean and median calculated from HR measured from the two methods. Lastly, the Bland and Altman Test is applied on the measured HR and the ±2*Standard Deviation (SD) is derived as 0.48 blood pulse per minute (bpm). This is not significant for measurement of resting HR for healthy individual, who has a typical resting HR of +1 bpm. The result obtained from the Bland and Altman Test affirms accuracy of MMSB to be used as an alternative to ECG system for HR measurements. Results obtained from all the four statistical tests are coherent and supports the use of MMSB as a viable alternative to ECG for measuring resting HR for healthy individuals.