How To Measure Your Blood Pressure Without A Cuff
I first started writing about mobile device health (mHealth) about seven years ago. When the Apple Watch was announced in 2015, I knew mHealth adoption would accelerate. In March 2015, Health Attitude: Unraveling and Solving the Complexities of Healthcare was published and in July that year a peer-reviewd journal published “How mHealth will spur consumer-led healthcare“. In both of these I expressed my optimism about how mHealth would ultimately have a profound impact on our health.
Before proceeding, I would like to clarify the difference between mHealth and telehealth, both terms being used more frequently. Telehealth refers to all instances of healthcare using modern technology such as Zoom, WebEx, Microsoft Teams, and other healthcare-specific systems to communicate, diagnose, and prescribe. mHealth refers to the concept of mobile self-care. The predominant examples are consumer technologies like smartphone and tablet apps which enable consumers to capture their own health data.
According to IQVIA, an American multinational company serving the combined industries of health information technology and clinical research, estimates there are now 318,000 mHealth apps. Many of these are trivial exercise related apps to record steps or miles. However, some mHealth apps are quite sophisticated. The Apple Watch can perform an EKG of your heart rhythm in 60 seconds and measure your oxygenation level in 15 seconds. In addition to the apps, the FDA has approved hundreds of mHealth devices.
An example of an mHealth device is a digital otoscope which attaches to a smartphone and enables a parent to take a picture of the inside of a child’s ear. A physician looking at the result can make a diagnosis. A more advanced mHealth device is smartphone-based microscopy. The technology is fast approaching the standard of laboratory-based microscopes but with a substantially lower upfront cost. Smartphone-based microscopy is even yielding portable handheld options for fluorescent imaging of viruses and DNA molecules. My book and journal article describe many more examples.
One mHealth device and app many have awaited is a way to measure blood pressure without the cuff. A Swiss company, Aktiia, developed a cuffless blood pressure monitor several years ago, and has now announced their wrist-worn device has received a medical device approval in Europe. The device could have a very positive impact on hypertension detection and management. It is now available for pre-order in the UK through the Aktiia website.
The obvious question is how does this device work without a cuff? The full explanation is quite long and technical, but a high level summary is the heart valve opens and closes and waves are created which propagate through the artery. A standard optical sensor, as shown in the picture above, captures data about what the waves do. The Aktiia technology uses pulse wave analysis to derive the exact blood pressure. Seems like magic but five clinical trials proved it to be accurate.
I will be surprised if Apple doesn’t acquire Aktiia or introduce its own technology using the Apple Watch for the task. We are still in the early stages of mHealth but I believe we will see many more amazing technologies emerge and have a very positive impact on the quality and cost of healthcare.