Transforming healthcare with wearable technology
Optical technology in smart watches and rings now supports medical-grade vital sign monitoring.
How consumer wearables enable medical monitoring
In the 20th century and for most of the 21st century so far, healthcare has been a service performed by professionals in dedicated locations, at specific times – normally in a hospital or clinic, supported by the results of tests supplied by laboratories.
The second quarter of this century is going to see a radical change: the introduction of new wearable devices will mean that monitoring, diagnosis and treatment can happen continuously, 24/7, wherever the patient is – at home, at work, even asleep in bed.
This technology is one of the critical enablers of a new ‘4P’ paradigm in medicine: the idea that a healthcare system delivers better outcomes for people, and often with fewer inputs from medical professionals and at lower cost, when it is personalized, predictive, preventive and participatory.
This 4P model is extremely attractive to advanced, industrialized countries that are facing the demographic timebomb of a rapidly aging population. The complex medical needs of the elderly threaten to overwhelm a tax base that is shrinking because of the declining ratio of workers to retired people. These countries have much to gain from wearable technology that can:
- Detect the warning signs of illness before it becomes critical
- Provide 24/7 monitoring of patients after surgery or other medical intervention, to reduce the risk of later complications
- Generate personalized diagnostic data to inform lifestyle choices, so that individuals can act to reduce their risk of conditions such as heart disease or diabetes, and enjoy a longer healthy lifespan
Advanced optical technology for medical-grade wearables
Providing the medical capabilities in a new generation of consumer wearable devices – smart watches, smart rings, earbuds, or smart patches – is sophisticated optical semiconductor technology: LEDs which emit light at tightly specified wavelengths in the visible or near infrared spectrum, and ultra-sensitive photodetectors (photodiodes) which are tuned to the same wavelength as the emitter.
Wearable technology with health monitoring capabilities also typically contains a dedicated analog front end (AFE) to amplify and digitize the signals from photodiodes. In addition, the AFE performs signal conditioning for electrical measurements such as electrocardiograms (ECG), for detecting heart conditions or abnormalities, as well as galvanic skin response (GSR), and bio-impedance.
Using a technique called photoplethysmography (PPG), the optical system can derive a range of vital signs from the measurements of light scattered in the body’s tissues and partially absorbed by the hemoglobin in the blood vessels in the wrist, ring finger or ear. Using PPG, algorithms can accurately determine:
- Heart rate
- Heart rate variability
- Blood oxygen saturation (SpO2)
When combined with our temperature sensor’s input for core body temperature, and electrocardiograms from electrodes touching the skin, a wearable device can provide a detailed picture of the wearer’s long-term health condition, potentially uncovering early stage disease markers even in apparently healthy people who are not aware of any symptoms.
Transforming medical monitoring and diagnosis
This capability is new to the science of medicine: before now, testing and monitoring of patients have been limited to a snapshot at a single point in time, and measured under the artificial conditions of a clinical setting. Diagnostic accuracy and insight will be transformed by the ability to analyze long time series of data, captured at all times of day and night, and when the patient is living their normal life.
This also marks a complete change in the use of consumer wearable devices, which today are still generally seen as a lifestyle accessory – something which can tell the wearer how active they have been (step counting) or how intense an exercise session was (approximate heart rate measurement), but which could not contribute to a medical assessment of health status.
We are now seeing the emergence of a new generation of wearable technology which is accurate and reliable enough to be used to inform medical diagnosis and treatment. Of course, this requires compliance with medical standards and approval from regulators such as the US Food and Drug Administration (FDA), or China’s National Medical Products Administration (NMPA).
At the forefront of this new development in medical-grade consumer wearable technology, our products set the standard for quality and reliability for the sensor components used in these devices.
ams OSRAM is already a trusted supplier and market leader of semiconductor products to the medical equipment industry. For instance, also in computed tomography (CT) and digital X-ray sensors for medical imaging which offer outstanding precision, high acquisition speeds, low noise and ultra-low power consumption.
Now our PPG solutions, such as the AS7057 and AS7058 AFEs, the SFH 7018 LED, and the SFH 2705 and SFH 2706 photodiodes, as well as the AS6221 temperature sensor, are providing the functionality and performance required in wearable devices that are intended to support medical use cases. This is demonstrated by a smart watch reference design developed by ams OSRAM.
In an internal study, ams OSRAM compared the measurements from an SpO2 reference clip, a blood oxygen monitor used in hospitals, and a chest strap for heart rate measurement, with the measurement data from the smart watch reference design. This comparison showed that the smart watch, using algorithms developed by ams OSRAM, complies with the specifications of the relevant standards.
Of course, every customer has to test their own design implementation, but our reference design shows that customers can be confident that they can achieve standards compliance for vital signs measurement in a smart watch when using ams OSRAM components.
And the increasing sophistication of AI software promises to make the detection of physiological markers even more accurate and reliable. A vision of what is possible by combining optical and electrical sensor technology with AI can be seen in the heartKIT™ AI reference model library from ams OSRAM partner Ambiq, a manufacturer of low-power AI processors. The heartKIT system uses vital sign measurements captured by ams OSRAM sensors.
More to come from consumer wearables
The ability to accurately measure vital signs in consumer wearable devices is already a transformative step for modern digitalized healthcare. But the future promises scope to track even more vital signs, realizing the vision of the 4P model for truly personalized and preventive healthcare: in future, your smart watch or smart ring might be monitoring how stressed you are, tracking the menstrual cycle, or even monitoring the concentration of alcohol in your bloodstream – all with the magic of PPG, temperature, electrical and spectral sensing technology performed by components from ams OSRAM.
So the future of personalized medicine is enabled by consumer devices that are convenient and comfortable to wear for long periods.
It is exciting to see how the technology is starting to transform medical care, and the potential it offers to help people live longer, healthier lives.
And with the advanced optical semiconductor technology and deep expertise at its disposal, ams OSRAM is the perfect partner for the device manufacturers who are developing this next generation of wearable products.