Continuous health monitoring

Continuous health monitoring and integrated diagnostic devices, worn on the body or used at home, have been suggested for the identification and prevention of early manifestations of disease. Some of the challenges to the capabilities of these devices have been the materials used, their abilities to generate accurate data, and validating the data analytics used to extract actionable conclusions from the obtained health data. These devices, or proposed devices, are part of an overall trend towards continuous monitoring in healthcare, with more devices offering continuous patient monitoring and hospital automation for better patient care.

Continuous health monitoring, especially for those at risk for or dealing with chronic disease, has been shown to be incredibly beneficial. An eight-year study, performed at the Stanford University School of Medicine and with collaborators, studied 109 people using a combination of wearable technology, genome sequencing, and microbial and molecular profiling. Through this technology, scientists were able to gather a baseline idea of a person's health, and from this baseline detect early signs of illness.

An understanding of the possible benefits has led to a further desire to manufacture devices that are non-intrusive, so consumers can wear and integrate them into their lives without interrupting their daily routine. There has also been a push in healthcare to increase the use of health monitoring at home for those patients dealing with chronic illnesses, to improve overall patient health.

With an increase in consumer use of connected devices and handheld devices, wearing medical devices for continuous monitoring is expected to be well received by consumers, especially for those with health concerns.Based on this, various companies are developing a variety of devices for continuous monitoring, along with the underlying data analytics to make the collected data informative for health professionals. For those with chronic conditions, these are seen as potentially offering improved quality of life and reduced hospitalizations.

Similarly, consumer devices once not considered to be health devices are being increasingly developed with secondary health monitoring functions built in. For example, Apple's AirPod headphones can monitor blood oxygen levels. And new patents from the company have suggested that next-generation AirPods could have EKG and ICG capabilities, both considered important for detecting heart failure. The Apple Watch already supports these features, with a heart rate monitor and fall detection; it can also measure respiration and alert a user to sleep apnea and is expected to include a thermometer in future generations to help with fertility planning.

Example of wearable consumer devices capable of continuous health monitoring.

One of the most well-known examples of continuous monitoring devices is the fitness tracker. Initially introduced to offer step-counting, heart-rate monitoring, and related fitness-tracking capabilities, many of these devices have added to their measuring capabilities to include respiration, blood oxygen, and related sensors to check for abnormalities in a baseline.

The Oura Ring.

The Oura Ring is one such device, and is capable of detecting slight variations in body temperature and has been suggested for use to catch early COVID-19 symptoms and incipient outbreaks. Another example is Amazon's Halo wristband, which monitors a wearer's voice, analyzes its tone, and reports on mood. Considered beneficial for mental health, this device is intended to help the wearer reflect on their various and varying emotional states to better understand what prompted them, and can allow an individual to avoid certain encounters, experiences, or people in order to reduce their overall stress. And the brand Hapi is developing a "smart fork," which can monitor how much and how quickly a user eats.

With an increase in the use of wearables, the relative size has also reduced to make the devices more efficient and convenient for a person to wear. For example, CART-I from SkyLabs is a wearable ring-type medical device offering continuous cardiac monitoring without user intervention. The device uses the finger because it provides accuracy and improved signal quality compared to other devices, and the ring form makes it easier to affix sensors to the skin and minimize noise in the data.

Example of a continuous glucose monitor.

Similarly, continuous glucose monitors have been introduced, allowing wearers and patients with diabetes to continuously monitor their blood glucose levels without needing to prick their fingers multiple times a day. These have been used for various health monitoring conditions and offer at-a-glance checks into a person's levels and can offer warnings for when a person's blood sugar begins to drop too low.

Example of the different sensors included on a smart toilet for continuous health measurements.

While wearables increase in popularity and are made easier to use and less intrusive to wear, there have been other attempts to develop new ways of continuous health monitoring. One such example that is non-intrusive and does not impact a user's daily routine is a toilet-based health-monitoring tool, or smart toilet. Smart toilets can measure urine and stool, both biologically rich in content, and have been shown to be capable of early diagnosis for disease. And with improvements in machine learning models, these systems are becoming better at classifying, quantifying, and interpreting data for easier diagnosis for clinicians and alerting patients to any issues with their systems.

In consumer cases, wearable devices are at the forefront of designing devices for continuous health monitoring, as these devices are typically unobtrusive and more likely to be worn and adopted by consumers over anything invasive or with needles. Wearable devices are built to offer users a freedom of movement, and often using devices that stick to the skin gets the best possible results without being invasive. For example, 3M has designed "skin-friendly" adhesives and devices, including foam tapes, non-woven and woven tapes, hydrocolloids, and polyurethanes.

Example of a skin attached glucose monitor using skin-safe tape.

For consumer and healthcare uses, this includes stick-to-devices, such as different tapes, diagnostic tapes, and spacers that are bioassay compatible and minimize the potential for chemical interference in devices, structured materials that offer precisely-shaped and micro-replicated surface structures or channels to provide a controlled dimension of physical, chemical, and optical properties; it includes microfluidic solutions, which allow for liquid samples through a device without invading the body, membranes and porous films that enable a device to capture particles or ensure samples flow properly, and flexible circuits to improve precision and accuracy of diagnostic devices.

Battery technology for consumer devices has also come a long way, with some considering further advances necessary to increase the overall adoption of devices. One such proposed example has been the use of thermoelectronics to sustainably supply power through the conversion of body heat into electric power. Early attempts at such systems were incapable of producing power large enough or stable enough for continuous operation of commercial health monitoring sensors. But, when paired with emerging Li-S batteries, these have been able to deliver power sustainably and continuously, with the Li-S batteries only needing half the charging voltage of Li-ion batteries.

Many of the benefits of continuous health monitoring have been studied in clinical and healthcare settings. Here, the use of wearables and non-intrusive or remote-patient monitoring tools has shown better performance than spot measurements, with a massive increase in the amount of clinical data capable of being captured. This data can further be analyzed through machine learning to derive further insights into a patient's overall health.

Bed-based sensors for increased continuous patient monitoring capabilities.

Further, remote patient monitoring has been suggested as a model to allow patients to be treated in the hospital for shorter periods of time and recover at home. Remote monitoring has been shown to provide similar levels of care and care management while reducing readmissions for patients and reducing the dangers of a transitional stage, when a patient leaves a hospital and returns home, when many people are at their most vulnerable. Connected devices can take the burden off of the patient and have been shown to communicate vital data to healthcare staff, and allow them to detect and address problems as they arise.

An extension of continuous patient monitoring for in-care situations, and for transition periods, hospitals and the US health system have increasingly turned to remote patient monitoring to improve patient outcomes and to reduce hospitalization visits and costs. These include mobile technologies that extend patient-caregivers beyond a traditional clinical setting and have been used for helping consumers with chronic illness track their symptoms. Many of these programs accelerated in their use and adoption during the COVID-19 pandemic, when remote patient monitoring and telehealth solutions provided a chance to reduce the burden on healthcare institutions and the shortages they faced on staff, equipment, devices, medicines, and infrastructure.

A virtual doctor's visit where a patient's vitals can be displayed through remote monitoring devices.

Remote patient monitoring systems include the physical and digital devices patients may use for monitoring vital signs and symptoms, digital solutions for logging and aggregating any necessary data and any increased patient context, and artificial intelligence systems that can reduce the need for a doctor to examine said data. They can provide alerts to healthcare providers when their attention is needed, or else alert a consumer to a need to seek medical attention.

With the increased interest and use of continuous monitoring technologies for health, especially as the use of these technologies increased during the COVID-19 pandemic, there have been concerns raised over the safety and privacy of these technologies—particularly the personal and private health data collected from these devices for analysis. And in the case of devices that use audio detection for snoring or sleep apnea, there are other sound data that could be collected. There is some concern over the possible surveillance of an individual person's health and the possible insights they could provide for marketers and companies to know more about individual tastes, when individuals are dieting or struggling with their weight, or managing chronic conditions such as diabetes, cancer, or mental illness.

Examples of regulatory pathways for home monitoring technologies before and during COVID-19.

Some concerns have been raised about which devices fall under the classification of medical devices, according to the U.S. Federal Food, Drug, and Cosmetic Act (FDCA), specifically Section (§) 201(h) of said act. Medical devices are required to meet FDA guidelines in order to be on the market. For example, when Apple launched an upgrade in 2018 to the company's smartwatch that allowed it to operate as a personal electrocardiogram (ECG), the FDA considered the app to be a moderate-risk device requiring special controls to provide reasonable assurance of its safety and effectiveness, and essentially classified the devices as a "Software as a Medical Device" class II device.

Furthermore, some of these technologies are not considered medical devices and are therefore not subject to FDA regulation. This could include apps that monitor a user's food consumption for the management of nutritional activity, or apps that monitors a user's daily exercise activity for improved cardiovascular health. The data they are harvesting can continue to be considered personal and health-based, but the regulations do not require them to be cared for as such. This has raised concerns over what this data could also be used for.