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Feasibility of long-distance heart rate monitoring using transmittance photoplethysmographic imaging (PPGI).

Amelard R, Scharfenberger C, Kazemzadeh F, Pfisterer KJ, Lin BS, Clausi DA, Wong A - Sci Rep (2015)

Bottom Line: For this purpose, a novel PPGI system was designed at the hardware and software level.Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction.Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring.

View Article: PubMed Central - PubMed

Affiliation: University of Waterloo, Department of Systems Design Engineering, Waterloo, N2L3G1, Canada.

ABSTRACT
Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restricts their use to at-rest short-term monitoring. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, many of which are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level. Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction. Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring. The results support the hypothesis that long-distance heart rate monitoring is feasible using transmittance PPGI, allowing for new possibilities of monitoring cardiovascular function in a non-contact manner.

No MeSH data available.


Example of the detrending procedure.A nonlinear trend was estimated in the original signal and subsequently removed, resulting in a signal with a stable mean. This process removed variability in illumination due to movement.
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f6: Example of the detrending procedure.A nonlinear trend was estimated in the original signal and subsequently removed, resulting in a signal with a stable mean. This process removed variability in illumination due to movement.

Mentions: where I is the identity matrix, λ is a relative weighting term, and D2 is the discrete approximation matrix of the second derivative. Figure 6 shows the recovery of a stable signal from a signal corrupted by movement using this detrending method. is the final processed PPGI signal.


Feasibility of long-distance heart rate monitoring using transmittance photoplethysmographic imaging (PPGI).

Amelard R, Scharfenberger C, Kazemzadeh F, Pfisterer KJ, Lin BS, Clausi DA, Wong A - Sci Rep (2015)

Example of the detrending procedure.A nonlinear trend was estimated in the original signal and subsequently removed, resulting in a signal with a stable mean. This process removed variability in illumination due to movement.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594125&req=5

f6: Example of the detrending procedure.A nonlinear trend was estimated in the original signal and subsequently removed, resulting in a signal with a stable mean. This process removed variability in illumination due to movement.
Mentions: where I is the identity matrix, λ is a relative weighting term, and D2 is the discrete approximation matrix of the second derivative. Figure 6 shows the recovery of a stable signal from a signal corrupted by movement using this detrending method. is the final processed PPGI signal.

Bottom Line: For this purpose, a novel PPGI system was designed at the hardware and software level.Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction.Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring.

View Article: PubMed Central - PubMed

Affiliation: University of Waterloo, Department of Systems Design Engineering, Waterloo, N2L3G1, Canada.

ABSTRACT
Photoplethysmography (PPG) devices are widely used for monitoring cardiovascular function. However, these devices require skin contact, which restricts their use to at-rest short-term monitoring. Photoplethysmographic imaging (PPGI) has been recently proposed as a non-contact monitoring alternative by measuring blood pulse signals across a spatial region of interest. Existing systems operate in reflectance mode, many of which are limited to short-distance monitoring and are prone to temporal changes in ambient illumination. This paper is the first study to investigate the feasibility of long-distance non-contact cardiovascular monitoring at the supermeter level using transmittance PPGI. For this purpose, a novel PPGI system was designed at the hardware and software level. Temporally coded illumination (TCI) is proposed for ambient correction, and a signal processing pipeline is proposed for PPGI signal extraction. Experimental results show that the processing steps yielded a substantially more pulsatile PPGI signal than the raw acquired signal, resulting in statistically significant increases in correlation to ground-truth PPG in both short- and long-distance monitoring. The results support the hypothesis that long-distance heart rate monitoring is feasible using transmittance PPGI, allowing for new possibilities of monitoring cardiovascular function in a non-contact manner.

No MeSH data available.