Bench Talk

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COVID-19 put a spotlight on the critical importance of timely healthcare data in aiding identification of infected and at-risk individuals. Well before the COVID-19 pandemic, however, healthcare wearables and other connected medical devices had proven their ability to provide long-term data needed to warn of potential health problems. Long after the pandemic has run its course, wearables are likely to find an expanded role in healthcare. By providing continuously updated measurements of the primary vital signs, wearables will help shorten time to treatment and relieve healthcare workers from performing necessary but time-consuming measurements, allowing them to focus on patient care. Here, we will explore how wearables offer an effective, long-term solution for delivering the essential patient data required by healthcare workers.

The Importance of Vital Signs Measurements

Vital signs measurements typically provide healthcare providers with the first indications of disease or chronic health issues. For this reason, any visit to a doctor’s office, clinic, or hospital has for decades begun with measurements of an individual’s primary vital signs, including body temperature, pulse rate, respiratory rate, and blood pressure. In some health conditions, other physiological metrics, such as peripheral oxygen saturation (SpO2), gain importance and are included in the list of vital sign measurements.

Through experience and training, physicians become aware of underlying pathologies when they find changes or abnormal readings in the primary vital signs, including:

• Body temperature, which can reflect the body’s immunological system’s response to infection or other conditions.
• Pulse rate, which can indicate underlying issues with the heart.
• Respiratory rate, which reflects overall cardiovascular fitness and provides a particularly important indicator of possible cardiopulmonary problems.
• Blood pressure, which reflects cardiovascular health and often suggests a wide range of other medical conditions.

Vital signs measurements became particularly important as the COVID-19 pandemic progressed. Healthcare professionals found that a relatively reliable COVID-19 predictor was elevated body temperature arising from the body’s immune response to infection by the SARS-CoV-2 virus that causes the disease. As a result, body temperature measurement quickly gained widespread use as a screener for possible infection. In fact, regular monitoring of the full set of vital signs remains particularly important for those deemed at-risk because of age, chronic health conditions, or conditions that can compromise the immune system.

For those infected with the SARS-CoV-2 virus, physicians monitor an extended set of vital signs to watch for the progression of the COVID-19 disease. For example, SpO2 measurement is critical for detecting reduced oxygen saturation levels associated with the infection’s ability to compromise the respiratory system. When oxygen saturation is reduced as it often is in COVID-19 cases, the respiratory rate can climb as the cardiopulmonary system attempts to gain more oxygen. Because further progression of the disease broadly impacts human physiology, frequent monitoring of a patient’s vital signs becomes essential.

Measuring Vital Signs with Wearable Technology

For each of these vital signs, wearable technologies are emerging or already in place for performing vital signs measurements for an extended duration at required update rates. For example, temperature wearables already play a role in hospitals, particularly in many neonatal units where infants wear tiny wireless temperature sensor patches that enable healthcare workers to monitor body temperature without disturbing their tiny patients.

Smartwatches and fitness bands with a built-in heart-rate monitor (HRM) not only provide their users with basic heart-rate measurement but also serve as the foundation for advanced detection of other health problems. Even routine heart-rate data can provide detection of atrial fibrillation or other arrhythmias, according to a study by the digital-health startup Cardiogram and the University of California San Francisco (UCSF) that used heart-rate data from HRM-enabled smartwatches. Further studies by Cardiogram and UCSF found that heart-rate data can provide an early indicator of diabetes or pre-diabetes conditions. Other types of heart-rate data analysis can provide heart-rate variability (HRV) measurements, which can signal physiological pathologies like cardiovascular disease and psychological factors such as anxiety or depression, known to impact health and well-being.

Using the same types of optical sensors used in HRM-capable smartwatches and fitness wearables, other analysis techniques can derive SpO2, respiratory rate, and blood pressure without the need for separate pulse oximeter clips, respiratory chest straps, or blood pressure cuffs. Similarly, other wearable technologies and measurement techniques can generate electrocardiograms with sufficient resolution to alert physicians to the need for more in-depth tests.

For long-term studies, wearables help ensure compliance by patients who are no longer required to visit clinics or even connect themselves at home to some bulky medical device. In fact, even with the variability and reduced resolution often found with some healthcare wearable measurements, the results are often sufficient to provide an early warning to healthcare providers.

Leveraging Key Enablers for Enhanced Healthcare Monitoring

Advanced sensor technologies and sophisticated analysis methods are only part of the healthcare wearable puzzle, but the remaining pieces needed for continuous vital signs monitoring are readily available. Wearable developers can take advantage of a broad array of wireless connectivity solutions, including microcontrollers with integrated radio subsystems for Bluetooth^® 5 and other connectivity options.

Wearable devices can maintain the integrity and high level of data confidentiality needed to support their use in the healthcare data chain using standard security mechanisms. Built around wireless microcontrollers, a wearable can send healthcare data securely to mobile devices, local networks, and even the cloud. These same Bluetooth-enabled devices also provide the foundation for contact tracing algorithms designed to stem future COVID-19 outbreaks without compromising personal privacy or security. These and other ultra-low-power devices provide the functionality and performance required to support more sophisticated healthcare algorithms without compromising the limited power budgets typically available in battery-powered products.

Conclusion

With their small size and comfortable fit, wearables can perform unobtrusive measurements at an update rate and measurement duration required by physicians and do so without further burdening healthcare workers. Fortunately, the underlying wearable technologies and analysis capabilities are in place to facilitate healthcare among populations working to recover from the pandemic and seeking more effective, long-term solutions for improved health and well-being.