Perhaps you’ve been barraged by emails from Fitbit that try and get you to buy one of their products during one of their many sales. Perhaps you’re a trendy techie and have a wearable in the form of a Galaxy or Apple Watch. Or perhaps you’re simply the owner of a smartphone made within the past few years. All these technologies have heart rate monitoring built into them from the get-go, and it is increasingly hard to get away from gadgets that don’t have some form of heart monitoring. With how ubiquitous the technology has gotten, I would like to look today at one of the patents put forward by Fitbit, one of the more popular brands when it comes to wearable fitness trackers. For this post, I’ll be using the information put forward by Google Patents, seen here.
One of the many figures in the patent, detailing the backside of the wearable.
The patent is simply titled as, “Wearable heart rate monitor,” and has a patent number of US8945017B2. It was originally filed on June 3rd, 2014, and was then approved on February 3rd, 2015. This makes the time to issue a little under a year, which is quite fast for an electronics product. The two inventors credited in the patent are Subramaniam Venkatraman and Shelten Gee Jao Yuen. Looking at the other patents associated with them, Venkatraman seems to have worked on more navigational devices, while Jao Yuen has worked on several other gyroscope-related projects. The assignee is, of course, Fitbit Inc. themselves. Officially, one of the classifications of the patent is, “signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal.” This one patent has 30 different claims to its name.
Of the 30 different claims in the patent, many of them tie into 2 main claims. The first is that the wearable heart monitor has a way to efficiently, accurately, and quickly determine the heart rate of the user. The second is to ensure that the wearable is capable of compiling the heart rate monitor’s data, including the heart rate data. This patent is aimed at both casual and advanced fitness enthusiasts, as the data gleaned from the wearable is handy to track. Runners, in particular, would find this tempting as it also mentions step tracking and other forms of movement.
The heart rate monitor works by using a waveform sensor, which reads signals at the surface of the skin. These signals are sent to the rest of the device, where the data is processed. The raw data from the sensor is rough and has a lot of noise from several factors, including movement and moisture. To remove the noise, the data has to be passed through several filters. From that data, a heart rate can be determined, and then presented to the user. Unlike the monitors of prior ages, this heart rate monitor would not rely upon disposable components, instead simply being able to be used multiple times by wearing it. In addition, the heart rate tracker would track more than just heart rate, including details about steps.
References: Venkatraman, S., & Yuen, S. G. J. (2014). Wearable heart rate monitor. Retrieved from https://patents.google.com/patent/US8945017B2/en
