Inventing What’s Next in Heart Rate Sensor Systems for Wearable Technology

Quite simply the most accurate heart rate sensor for wearable technology available today.


heart rate sensor

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Whole > Sum of the parts

Many people think you can create accurate biometric wearable devices by piecing together some LED’s, some firmware, some algorithms, and calling it a heart rate sensor. It’s not that simple.

Valencell has learned over many years of R&D, trial & error, and product development that the systems approach to building biometric wearable devices is most effective. Everything must be designed and developed to work together from the start – the optomechnanics, the firmware, the algorithms, and the testing & validation processes.

  • You can have the best optomechanics in the world, but if your algorithms are not optimized for that signal, it won’t work.
  • Likewise, you can have the best algorithms in the world, but if you have a poor signal coming from the sensor, it won’t work.
  • Finally, even if you get the hardware and the software working together, you have to test and validate that it works on people of all shapes, sizes, colors, genders, and fitness levels.

Get there faster with Valencell.

Wearable Technology - Headphones


Scalable to multiple form-factors such as earbuds, smartwatches, armbands and wrist devices.

Valencell’s heart rate sensors can be used in wearables and hearables for virtually anyone, anywhere, doing anything.
PerformTek® heart rate sensor technology is the only continuous heart rate sensor technology proven accurate during virtually any exercise and in virtually any environment. Read more about our testing methods here.

We’ve been innovating in optical heart rate sensor technology for 10 years, before wearables even existed. Our levels of accuracy are proven by independent scientific validation and by users of Valencell-powered products every day.


Optical Heart Rate Sensor Design

Our sensor technology gives wearable devices the ability to continuously and accurately measure weak blood flow signals even during extreme physical activity. PerformTek achieves this with a state-of-the-art, ultra-miniaturized heart rate sensor module small enough to fit within an audio earbud, smartwatch, or other wearable device. The sensor module includes an optical emitter, an optical detector, specialized optomechanics and an accelerometer.

How it Works
Wearable Technology - How it Works
How it Works


Wearable Technology

Photoplethysmography (PPG) is not new. It’s been used for decades to measure blood flow changes and translate these changes to pulse rate. Until now, products using PPG have been too large and uncomfortable for consumer use and have not been effective at measuring blood flow during exercise or outdoors. Our patented PerformTek biometric technology has solved many of these problems.

Like the traditional PPG approach, PerformTek heart rate sensor technology measures weak blood flow signals by shining light at the skin with an optical emitter and sensing the scattered light with a photodetector. The key differences are Valencell’s patented optomechanics and signal extraction methodologies, which employ active signal characterization to actively remove optical signals associated with motion artifacts (such as skin motion and footsteps) and environmental exposure (such as sunlight) from the photodetector.

It’s like active noise cancellation for biometric wearables. The result is a clean signal that contains more accurate information about blood flow. Because blood flow modulates with heart rate and respiration rate, PerformTek-powered algorithms can accurately extract heart rate, RR-interval, respiration rate, and other blood flow parameters even during intense exercise. To gauge user activity level and to generate activity context, the PerformTek earbud sensor module leverages the accelerometer that is built in to the sensor module. The PerformTek signal extraction method applies a proprietary algorithm to the accelerometer signal to measure running, cycling and activity cadence and to estimate speed and distance traveled. Valencell also estimates VO2 and calories burned by processing both the accelerometer signal and blood flow signal.

Heart Rate Sensor API

Valencell’s accurate biometric signal extraction method is coded in firmware on a digital signal processing chip (DSP chip). Application developers can communicate with this DSP chip through the PerformTek API, which allows app developers to access this data and make virtually any health, medical or fitness application their minds can dream up.

To learn more about integrating our heart rate sensor technology into your ideas, see our Access page.