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A smart wristband connected wirelessly to a smartphone could herald a new wave of wearable devices to monitor personal health and the environment.
This cutting-edge technology – a plastic wristband with a flexible circuit board and biosensor - could easily be added to existing wearable devices that monitor heart rate and physical activity. Thanks to recent achievements in developing ever-smaller sensors, the market for wearable devices is rapidly growing, as is the desire to monitor one’s health.
Current wearables can measure only a handful of physical parameters such as heart rate and exercise activity. The ability for a wearable device to monitor the counts of different cells in our bloodstream would take personal health monitoring to the next level.
Abbas Furniturewalla, Former Undergraduate Researcher in the Department of Electrical and Computer Engineering at Rutgers University New Brunswick
"It's like a Fitbit but has a biosensor that can count particles, so that includes blood cells, bacteria and organic or inorganic particles in the air," added Mehdi Javanmard, assistant professor within the Department of Electrical and Computer Engineering at the School of Engineering.
The wristband’s biosensor features a channel or pipe thinner than the diameter of a human hair with gold electrodes rooted inside. Blood samples are attained through tiny pinpricks with the blood being fed through the channel and blood cells counted.
A circuit processes electrical signals, while a micro-controller digitizes the data which is transmitted wirelessly via a Bluetooth module. The data is communicated to an Android smartphone with an app that processes and displays the data, but it can be used on iPhones or other smartphones too.
“The platform contains a standard polydimethylsiloxane (PDMS) microfluidic channel integrated on a wristband, and the circuitry on the wristband is composed of a custom analog lock-in amplification system, a microcontroller with an 8-bit analog-to-digital converter (ADC), and a Bluetooth module wirelessly paired with a smartphone,” the duo write in their study, published in Microsystems and Nanoengineering.
Such technology – a microfluidic impedance cytometer - would have application in the field, offices, and hospitals to help healthcare professionals obtain rapid blood test from patients without the need for costly and large laboratory-based equipment. Counting cells usually requires the use of fluorescence or impedance-based measurements which require labeling of biological cells. The impedance cytometry employed in this wristband uses electrical measurements as an alternative – and doesn’t require any labeling. Furthermore, it can be used to detect proteins and nucleic acids, as well as cells.
"There's a whole range of diseases where blood cell counts are very important," explains Javanmard, who is senior author of the study. "Abnormally high or low white blood cell counts are indicators of certain cancers like leukemia, for example."
Blood cell counts can be used to indicate illnesses such as internal bleeding where low blood cell counts would be present. The system can be employed to investigate to a varied range of biomarkers by switching the standard microfluidic channel with microfluidic channels designed for specific biomarker isolation.
These next-generation wristbands could have a variety of applications in biomedical and environmental monitoring and would allow patients to infinitely keep tabs on their health and send results to their physicians remotely. Monitoring body health in such a way could be critical for detecting illnesses early on, which in turn would enable more accurate diagnosis, more effectual treatment, and reduce morbidity or health repercussions.
"This would be really important for settings with lots of air pollutants and people want to measure the amount of tiny particles or dust they're exposed to day in and day out," Javanmard said. "Miners, for example, could sample the environment they're in."