Non-invasive device measures a patient's blood flow
Scientists have developed a portable device that can scan patients' bodies to monitor their blood flow, which can help to diagnose and monitor a myriad of medical conditions University of Waterloo

Scientists from the University of Waterloo in Ontario, Canada have developed the first portable, non-invasive, touchless device that is able to fully image a patient's body to monitor the blood flow in their body, which could revolutionise early detection of heart problems.

The patent-pending technology is known as Coded Hemodynamic Imaging and it is able to monitor a patient's blood flow at multiple arterial points simultaneously without making direct contact with the skin. The device uses Photoplethysmography (PPG), a light-based method invented in the 1930s for tracking cardiovascular activities that detects changes in light intensity to detect changes in blood volume in a particular area of the body.

Until now, PPG has only worked when it has been in close proximity with the patient's body, but the new device has sensors that are able detect hemodynamic waveforms from a distance.

This would be hugely beneficial in detecting heart problems ahead of time, as well as in assessing the condition of burn patients, patients who have contracted highly contagious diseases, or infants in neonatal intensive care who are so small that their tiny fingers are unsuitable for traditional monitoring.

"Traditional systems in wide use now take one blood pulse reading at one spot on the body. This device acts like many virtual sensors that measure blood flow behaviour on various parts of the body. The device relays measurements from all of these pulse points to a computer for continuous monitoring," said Robert Amelard, a PhD candidate in systems design engineering at Waterloo and recipient of the prestigious Alexander Graham Bell Canada Graduate Scholarship from the Natural Sciences and Engineering Research Council of Canada.

"By way of comparison, think of measuring the traffic flow across an entire city rather than through one intersection."

Even better, the device can be used to scan multiple patients at once and from a distance, making it perfect for a mass emergency situation where many patients are being brought into the emergency room at the same time.

"This technology provides for a more predictive approach to monitor vitals and the potential for its use is extensive, such as indicating arterial blockages that might otherwise go undetected, or warning older adults who risk falling as a result of getting dizzy when they stand," said Professor Alexander Wong of the Faculty of Engineering at Waterloo and Canada Research Chair in Medical Imaging Systems.

The study, entitled "Feasibility of long-distance heart rate monitoring using transmittance photoplethysmographic imaging (PPGI)" is published in Nature's Scientific Reports journal.

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