Automated Remote Pulse Oximetry System (ARPOS)

Abstract

Current methods of measuring heart rate (HR) and oxygen levels (SPO2) require physical contact, are individualised, and for accurate oxygen levels may also require a blood test. No-touch or non-invasive technologies are not currently commercially available for use in healthcare settings. To date, there has been no assessment of a system that measures HR and SPO2 using commercial off-the-shelf camera technology that utilises R, G, B, and IR data. Moreover, no formal remote photoplethysmography studies have been performed in real-life scenarios with participants at home with different demographic characteristics. This novel study addresses all these objectives by developing, optimising, and evaluating a system that measures the HR and SPO2 of 40 participants. HR and SPO2 are determined by measuring the frequencies from different wavelength band regions using FFT and radiometric measurements after pre-processing face regions of interest (forehead, lips, and cheeks) from colour, IR, and depth data. Detrending, interpolating, hamming, and normalising the signal with FastICA produced the lowest RMSE of 7.8 for HR with the r-correlation value of 0.85 and RMSE 2.3 for SPO2. This novel system could be used in several critical care settings, including in care homes and in hospitals and prompt clinical intervention as required.

Remote Photoplethysmography (rPPG): A State-of-the-Art Review

“…Previous research studies have used a variety of different equipment and set-up to capture data from participants to obtain vital signs. Thermal camera [67], [68], [69], [70], Charge-Coupled Device (CCD) camera [71], [72], other affordable web cameras or those built-in laptops [73], [74], [75], [76], [77], [78], [79], [80], [81], MS Kinect V2 [82], [83], [66], Kinect Azure [84], GoPro camera with a drone [85] and smartphone [86], [87], [88], [89], [90], [91], [92], [93], [94] cameras have been previously used to obtain a person’s vital signs. Table V and Table IV show different studies conducted with various equipment and the vital sign under observation.…”

“…rPPG system measures the HR by analysing the skin pixel intensity of the heartbeats over time; the skin flashes darker and lighter as more and less blood flows through the region. It measures SpO 2 by using the optical absorption differences across the visible and near-infrared wavelength regions between Hb and deoxy-Hb [23], [66]. Various techniques from different research systems have been evaluated, critiqued with their gaps, summarised and presented in this research paper.…”

Everything About Pulse Oximetry—Part 2: Clinical Applications, Portable/Wearable Pulse Oximeters, Remote Patient Monitoring, and Recent Advances

“…The real-time ARPOS system can currently measure the vitals of up to 6 people at a distance of 4.5 meters from the camera, using affordable, off-the-shelf hardware that is easy to set up. 27…”

“…The technology can also potentially be used to scan larger crowds or gatherings to identify potentially dangerous patterns of vital signs and trigger rapid intervention. 27…”

“…The real-time ARPOS system can currently measure the vitals of up to 6 people at a distance of 4.5 meters from the camera, using affordable, off-the-shelf hardware that is easy to set up. 27 The new system could be used in different settings such as care homes, hospitals, communities, and private homes. It can communicate vital signs in real time between patients and carers, emergency services, or private users without the need to store personal data.…”