In this article, AZoSensors explores how wearable blood pressure sensors could revolutionize blood pressure monitoring, contributing to a future with more accessible healthcare.
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What Are Wearable Blood Pressure Sensors?
Progression in the health field has led to consumer-grade smart wearables, such as wearable blood pressure sensors connected to electronic devices that aid in monitoring and recording physiological data in real time. The development of flexible, sensitive and lightweight wearable blood pressure sensors that are inexpensive and wireless can be significant for various applications in the wearable and portable device industry.
Wearable blood pressure sensors record blood pressure measurements accurately with a possible improvement to hypertension screening as well as being able to detect high blood pressure or hypertension during the night and during exercise. These types of hypertension have been associated with worse health outcomes. With hypertension being a key cause of morbidity and mortality worldwide, consumer-grade wearable blood pressure sensors may be a revolutionary health tool.
The use of wearable blood pressure sensors for monitoring hypertension is significant, with the World Health Organization (WHO) describing high blood pressure (BP) as a common but serious disorder, if not treated, being measured at 140/90 mmHg or higher.
Approximately 1.28 billion adults globally between the ages 30-79 have hypertension, with two-thirds of the population residing in low- and middle-income countries. While those in high-income countries may have easy access to medical aid for hypertension and related disorders, those in low-income countries may find low-cost wearable blood pressure sensors more useful, enabling continuous blood pressure measurement without immediate medical aid.
WHO has stated hypertension as a significant cause of premature death at a global scale and with one of the global targets being to reduce the prevalence of this disorder for non-communicable diseases by 33% by the year 2030, the use of wearable blood pressure sensors would be a great strategic approach.
The most commonly used approach to BP measurement in medicine is through a sphygmomanometer, followed by listening to the Korotkoff sounds, which is a non-invasive approach to measuring blood pressure; however, this requires a medical professional.
Automatic methods include a cuff that would wrap around the arm with a built-in pressure sensor that detects pressure oscillations while deflating the cuff, providing the BP measurement.
In comparison, using a painless and cuffless sensor that provides consistent monitoring of blood pressure can be more dynamic than cuff-based approaches. These sensors can be attached to portable devices, including smartphones, through wearable blood pressure sensors, continuously measuring the user’s blood pressure in real-time throughout their everyday functions.
Additionally, wearable blood pressure sensors may be more useful for those without access to conventional blood pressure methods, such as first aiders within workplaces and schools that could effectively use wearable blood pressure sensors for those requiring medical assistance.
Wearable Blood Pressure Sensors: Research Innovations
Available non-invasive BP measurement devices consist of the arterial tonometry method, vascular unloading technique, and the pulse waveform characteristic parameter method. However, research into wearable blood pressure sensors has developed various manufacturing methods, including using low-viscosity fluid, enabling high sensitivity and a rapid response rate within tens of milliseconds once stimulated.
An innovative research team developing wearable blood pressure sensors has created a device with a microfluidic channel on a configurated gold metal transducer between two sensitive polymer layers (Ion 2021). The wearable blood pressure sensors include a microfluidic channel filled with an electrolyte to enable volume changes from an external force, such as a waveform of the human pulse, to be felt by the transducers.
Within this wearable blood pressure sensor development, the metal transducers are configured on a substrate known as polyethylene terephthalate (PET) film due to being cost-effective with properties including transparency, hardness, mechanical strength, and resistance to temperature. The second layer of wearable blood pressure sensors consists of polydimethylsiloxane (PDMS), which is a desirable option due to its high-level flexibility as well as high thermal and dielectric characteristics. Additionally, metallic transducers, such as gold, silver, aluminium and copper, are common materials when developing flexible sensors such as wearable blood pressure sensors as a result of their good electrical conductivity.
This technological innovation aims to develop low-cost, flexible and accurate wearable blood pressure sensors with high sensitivity to minimal pressure, a significant factor when accurately calculating hemodynamic parameters, especially in strenuous conditions such as during exercise when the heart rate is elevated.
Other research into wearable blood pressure sensors also includes the integration of photoplethysmography (PPG) in smartphone applications where blood pressure can be measured through PPG signals using the camera or a portable detector attached to the smartphone that detects changes in blood flow in various body parts during the cardiac cycle. Wearable blood pressure sensors that are developed into smartphones may be more easily accepted by global populations through new mobile phone upgrades that have the wearable blood pressure sensors embedded as part of their novel feature.
Wearable Blood Pressure Sensors: Commercial Landscape
Approximately 20% of the population within the US currently own a smart wearable device, with this global market predicted to grow at a CAGR of 25%, leading to $70 billion in sales by 2025. Additionally, with these devices already attempting to embed wearable blood pressure sensors with low accuracy, this type of feature can only become more evolved, enabling wearable blood pressure sensors to become a ubiquitous addition to smart devices.
With an estimated 1.28 billion adults with hypertension in low- and middle-income countries as well as 46% of adults unaware of carrying this condition, the market for wearable blood pressure sensors is significant and could alleviate a global health burden.
Wearable Blood Pressure Sensors: Future Outlook
The prevalence of hypertension and cardiac health has led to higher awareness in global populations that are more likely to use technology, including wearable blood pressure sensors, to take control of their health.
While wearable blood pressure sensors require further research into creating an accurate and low-cost device, this approach to raising and instilling health precautions with continuous monitoring may ease the global health burden of hypertensive conditions. The use of wearable blood pressure sensors may also aid in accomplishing the health goal set out by WHO to reduce hypertension in global populations.
Additionally, wearable blood pressure sensors would be significant for many populations due to the financial burden on healthcare systems. A study predicting the total cost of treating hypertension within the US in 2030 calculated this may cost approximately $50.3 billion, including both direct medical costs and indirect costs related to losing productivity due to morbidity and mortality in the population.
The use of wearable blood pressure sensors with accurate blood pressure measurement may reduce the population that experiences hypertension and more, those that experience worse health outcomes that eventually lead to mortality.
Having a device that includes wearable blood pressure sensors that continuously monitors blood pressure may encourage more people to seek healthier lifestyles that reduce blood pressure, which is also detectable by wearable blood pressure sensors.
References and Further Reading
Al-Qatatsheh A., et al. (2023) Blood pressure sensors: Materials, fabrication methods, performance evaluations and future perspectives. Sensors (Basel, Switzerland). Accessed July 16. https://pubmed.ncbi.nlm.nih.gov/32796604/.
Arakawa T. (2018) Recent research and developing trends of wearable sensors for detecting blood pressure. Sensors. 8(9), p. 2772. doi:10.3390/s18092772
Bayoumy K, et al. (2021) Smart wearable devices in cardiovascular care: Where we are and how to move forward. Nature Reviews Cardiology. 18(8), pp. 581-599. doi:10.1038/s41569-021-00522-7
El Abbasi M. K., et al. (2022). Wearable blood pressure sensing based on transmission coefficient scattering for microstrip patch antennas. Sensors. 22(11), p. 3996. doi:10.3390/s22113996
Ion M, et al. (2021) Design and fabrication of a new wearable pressure sensor for Blood Pressure Monitoring. Sensors. 21(6), p. 2075. doi:10.3390/s21062075
Konstantinidis D., et al. (2022) Wearable blood pressure measurement devices and new approaches in hypertension management: The Digital Era. Journal of Human Hypertension. 36(11), pp. 945-951. doi:10.1038/s41371-022-00675-z
Lazazzera R, et al. (2019) A new wearable device for blood pressure estimation using Photoplethysmogram. Sensors. 19(11), p.2557. doi:10.3390/s19112557
World Health Organization. Hypertension. Accessed July 16, 2023. https://www.who.int/news-room/fact-sheets/detail/hypertension.
Zhao L., et al. (2023) Emerging sensing and modeling technologies for wearable and Cuffless Blood Pressure Monitoring. npj Digital Medicine. 6(1). doi:10.1038/s41746-023-00835-6