Optimization of Heartbeat Detection in Fiber-Optic Unobtrusive Measurements by Using Maximum A Posteriori Probability Estimation

Abstract

This paper deals with an optimized heartbeat detection multimethod by using maximum a posteriori probability (MAP). The approach was derived for unobtrusive fiber-optic measurements of cardiac activity. Multiple independent detection methods were selected and characterized by their delays and variability referring to cardiac electrical excitation (R waves). Validation of the approach was performed in two experiments involving 24 participants: 10 interferometric signals were recorded at rest, 14 with variable heart rate after physical exercise. The proposed MAP heartbeat detection was assessed by a cross validation in 250 iterations. Obtained results show the overall efficiency, which was estimated by a product of the sensitivity, precision, and variability of heartbeat detections, yields 97.04 ± 3.36% for the experiment with physical exercise and 97.07 ± 4.49% at rest. The method's accuracy guarantees that the heartbeat detections differ for 22 ± 5 ms and 22 ± 3 ms from the ECG reference in the two types of experiments, respectively.

Ballistocardiography and Seismocardiography: A Review of Recent Advances

“…Jansen et al applied a detection method based on a "tem-393 plate matching" rule by evaluating a correlation function in a 394 local moving window [64], a method which was further refined 395 and developed by Shin et [66], [67], and methods which use wavelets 403 to preprocess the signal prior to peak detection [53], [68].…”

“…The results showed 95.2% of sen-399 sitivity and 94.8% of specificity in average for five subjects and 400 three types of BCG signals. Additional methods for heartbeat 401 detection from BCG signals include those which combine differ-402 ent estimators [46], [66], [67], and methods which use wavelets 403 to preprocess the signal prior to peak detection [53], [68].…”

A Method of Detecting Heartbeat Locations in the Ballistocardiographic Signal From the Fiber-Optic Vital Signs Sensor

“…There are a number of fiber-optic strain gauges designed to monitor vital signs, of which the most popular are interferometers [17], micro-[10]- [11] and macrobending sensors [18], and fiber Bragg gratings (FBGs) [18], [19]. Many researchers took a liking to the FBGs due to their spectral encoding, easy multiplexing, and selfreferencing capabilities [20].…”

Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures

“…[56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75] Body movements caused by the function of the lungs and heart cause phase changes between signals (sensing and reference) and could be identified as a series of time-variable interference patterns. Thus far, in research on the acquisition of physiological signals, fiber-optic interferometers have been tested in their most popular configurations, i.e., Michelson, Mach-Zehnder, and Sagnac interferometers.…”

“…[58][59][60] The popular Michelson interferometer has been the most widely studied. [61][62][63][64][65][66][67][68][69][70][71][72] As shown in Fig. 4, the Michelson interferometer consists of two optical paths (arms), i.e., the sensing and reference fibers.…”