Speckle Vibrometry for Instantaneous Heart Rate Monitoring

Figures

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  Figure 1. Schematic of a near-focused camera system for speckle vibrometry [17].

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  Figure 2. The illustration of the experimental setup of speckle vibrometry. The two figures on the right are illustrations of the camera and laser positioning from two view angles: from the end of the bed and from the right side of the bed. The elevation angle of the camera and laser is around 120 degrees. The figure on the left is the real-life experimental setup that we deployed for data acquisition, where the green dashed line indicates the laser beam and the red rectangle indicates the camera. This configuration is applied to all three sleeping positions: supine, lateral, and prone.

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  Figure 3. Ensemble average of SV cardiac waveforms from one participant in the time domain. The x-axis and y-axis are both normalized, rendering an arbitrary unit (a.u.).

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  Figure 4. Bland–Altman plot: on-skin IHR comparison between SV (i.e., Nvalid) and ECG (i.e., Mvalid).

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  Figure 5. Bland–Altman plot: on-comforter (32 mm) IHR comparison between SV (i.e., Nvalid) and ECG (i.e., Mvalid).

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  Figure 6. Bland–Altman plot: on-bedsheets (32 mm) IHR comparison between SV (i.e., Nvalid) and ECG (i.e., Mvalid).