Fitbit files patent for a finger-based blood pressure monitor
Fitbit has a new patent with the United States Patent Office for an innovative blood pressure monitor that captures measurements from the finger.
Details of the patent
The patent application is a continuation of a previous application filed in December 2017, titled “Finger Blood Pressure Cuff.” The new device demonstrates Fitbit’s innovation in developing automated systems for measuring a user’s blood pressure using the oscillometric blood pressure measurement (OBPM) technique.
OBPM systems are popular due to their ease of use and do not require a trained operator. However, they can be affected by hydrostatic pressure, which varies based on the device’s placement relative to the heart.
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Fitbit’s patented device aims to overcome the drawbacks of traditional OBPM systems. It does this by being less cumbersome and more accurate, addressing a crucial need in the market for reliable and convenient blood pressure monitoring devices.
Understanding traditional blood pressure monitors
Traditional blood pressure monitors typically involve an inflatable cuff which is attached around the user’s upper arm. As the cuff inflates, it squeezes the artery underneath until it’s fully occluded and blood flow is temporarily stopped. As the cuff slowly deflates, the device measures the vibrations in the artery as the blood starts to flow again. These vibrations are used to calculate the systolic and diastolic blood pressure.
However, this method can sometimes present difficulties for users. The cuffs can be cumbersome and uncomfortable. Furthermore, for accuracy, they need to be positioned correctly. This is typically around the upper arm at the heart level, which can be challenging for some users. Additionally, the hydrostatic pressure (the pressure exerted by a fluid at equilibrium due to the force of gravity) can affect the results. This means that the position of the arm relative to the heart can impact the readings. Wrist-worn OBPM devices, while more portable, are even more sensitive to such positioning issues and thus, often less reliable.
Fitbit’s innovation in blood pressure measurement
Fitbit’s newly patented technology intends to address these concerns. Their device measures blood pressure in a fundamentally different way. It employs a miniaturized and inflatable bladder that is placed inside a hole designed to receive a human finger. This design simplifies the process and makes it more comfortable for the user.
The new device offers more than just comfort. The innovative pump and pressure sensor system inside the device can control the inflation rate by modulating factors such as duty cycle, voltage, or drive frequency. This adds an extra level of precision in measuring blood pressure, which could potentially lead to more accurate readings.
In terms of positioning, the new device addresses another major issue found in traditional monitors. Because it’s designed to be used with a finger rather than the upper arm or wrist, the concerns over hydrostatic pressure variations are significantly mitigated. As the finger is more frequently at heart level, whether the user is sitting, standing, or lying down, the device can provide more consistent readings.
Moreover, the compact design makes it portable and easy-to-use. This could potentially increase the frequency of measurements, leading to better blood pressure management.
The big picture
Up until now, Fitbit’s portfolio has primarily revolved around smartwatches and fitness bands. Its smart scale is the one notable exception. However, with its recent integration into Google, we could anticipate a subtle shift in the company’s trajectory. It wouldn’t be a shock to see Fitbit pivoting towards broader health tracking solutions, potentially reducing its emphasis on wrist wearables. Given Google’s apparent focus on promoting its Pixel Watch, Fitbit might be prompted to streamline its offerings within the wearable sector.
Mind you, this is not Fitbit’s first patent for a blood pressure monitor. Last year it had a filing for a traditional looking blood pressure cuff that has some intelligent functionality built-in. But so far we are yet to see this translated into a real-world product.
Fitbit’s new blood pressure monitoring device, according to the patent details, will likely be portable and provide more accurate results compared to existing devices. By redesigning the method from a cumbersome arm or wrist cuff to a finger-based system, Fitbit aims to provide a more comfortable, reliable, and user-friendly way for individuals to keep track of this crucial health metric.
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