10 Optical Heart Rate Monitor Considerations for New Wearables
You’re sitting in a planning meeting. The team has just come up with some pretty amazing ideas for the new wearable device with an optical heart rate monitor you’re adding to your product line. Everyone’s really excited and the planning process gets its start as they all turn to you: who should we partner with for the biometrics?
Suddenly you realize you’re not entirely sure where to begin.
We’ve heard this before. Many times. After all, Valencell has been involved in more biometric wearable projects than any other company in the world. So we thought we’d help ease your mind by providing 10 things you should look for in your search for a biometric sensor system that meets your needs.
Before we dive into the details, it’s important to understand one particular aspect of biometric wearables. We use the term “system” very deliberately because getting biometrics right in wearables requires a system in which the key components (hardware/optomechanics, firmware, signal processing, data assessments and device validation testing) need to be designed and built to work together seamlessly. You can think of these things like links in a chain and weakness or failure in any one of these links will cause major problems for your product.
So without further ado, here are the 10 things to consider in selecting a biometric sensor system for your next wearable:
1. Get proof that it works before you get started.
This might seem pretty obvious, but anyone who has brought a biometric wearable to market will tell you thatthe hardest part of the product development cycle is getting the biometric sensor system to work well enough to meet your requirements . Your starting point should be a working reference design. Any HR technology vendor you are considering working with should be able to show you a working reference design that performs at the levels of precision and accuracy you require. If the device is meant for exercise monitoring, then make sure the reference design has been tested during interval training and outdoors (through shadows), where most biometric wearables fail.
Some other ways to validate the technology include:
- Find independent testing and validation with published white papers outlining the methodologies and results. It is important that the results are presented by a respected third party, whose credentials you trust.
- Test other companies’ products in the market that are using a particular vendors technology. Are their customers pleased with the performance? How does it perform in your tests?
2. Does the technology provider know your market and can they support your requirements?
Applications for biometric wearables are broad. Make sure your technology provider has the capabilities and experience to deliver on the device you want to build. The right form factor, the right metrics, the right levels of accuracy, and the right user experience all play huge roles in a product’s success.
For example, consumers have clearly demonstrated their desire for biometrics in their fitness devices — but they are now asking for more compelling user experiences. Will yours have accurate measurements in the fitness categories they’re most interested in?
And speaking of accuracy, you should double-down when it comes to accuracy if you’re developing for any health-related purpose whatsoever.
Also, if you’re thinking about creating product for some of the hot new expansion areas, like gaming or first responders, you’ll have greater success if you’re working with a vendor who has demonstrated experience within your intended uses and in your desired form factors.
3. Do they have expertise in optomechanics?
Optomechanical design is a critical factor in accurate biometric wearables. The team you select should have extensive optomechanical expertise. They should understand how light is coupled to & from the body to optimize the signals indicating blood flow and minimize environmental noise. A strong team will be sure that the right wavelengths are being used for the chosen device body location and form factor. Understanding things like emitter/detector spacing and appropriate displacement between the skin and the sensor will ease the way to a viable product.
4. Are they using advanced signal extraction methodologies?
Because of the complexities in individual bodies, it’s critical for all technology developers to have keen understanding of signal extraction algorithms, particularly something called active signal characterization. Some of the biggest challenges in getting optical biometric sensors to work in wearables are being able to identify and characterize both motion and environmental noise that can corrupt signals. This “active noise cancellation for OHRM” allows the biometric sensor system to report accurate data. It should be noted that the algorithms that implement the signal extraction method must be demonstrated in the exact hardware that will go to market. This is because the algorithms must be updated depending on the hardware configuration.
5. What biometrics can you get from the sensor system?
Basic heart rate measurement is quickly becoming a minimum requirement for wearables. More advanced metrics will define the future, so take a serious look at what metrics you can get from the system. Does it support continuous heart rate or is it just spot measurements taken periodically? Can it deliver more advanced metrics like RR interval (HRV), breathing rate, or blood pressure? And, perhaps more importantly, can the vendor prove to you they can deliver those metrics? Actions speak louder than words.
Also think about the roadmap. Where is the vendor headed? You’ll want to be sure that their future product roadmap aligns with your product plan. Moreover, you should make certain your biometric sensor partner can provide you with field upgradability for your hardware, to mitigation bugs and to assure feature improvements will be painless.
6. What are their product testing capabilities?
When you partner with vendors for core components of your product, it’s important to know how they test their own work, but also how they test their product within your device. If they offer prototype testing services, you’re heading in the right direction. But be sure to ask if they can test your intended use cases. How do they conduct that testing?
Also, find out what their testing protocols involve. Are they simply running a steady-state 10-minute treadmill test for a fitness use case? If that’s how you expect your product to be used, then that is appropriate. If you believe it will be used outdoors, for interval training, by people of all ages, fitness levels and skin color — especially if you plan to market it this way — you should expect those tests to be run. The testing should match how you expect your customers to use the product.
7. Proven Experience
We’ve alluded to this earlier, but it’s critical to understand what other products on the market are using the tech you’re looking at including in your product. Analyzing consumer reviews of the OHRM in those devices can give you critical insight into how that component will work in your device.
If their technology is in products on the market today, how accurate are those products? Are the product reviews positive (at least as it pertains to the heart rate monitoring and biometrics component)?
8. Team Expertise
You should get an understanding of the skills and expertise of the vendor’s team. Do they specialize in hardware? Optics? Firmware? Algorithms? What are their core competencies?
Look up the people that work there on LinkedIn. Check out their engineers’ backgrounds and skills. This will give you a more realistic picture of their capabilities as a group.
Look at their website. What positions are they hiring for? This will provide some insights on where they are investing in the future.
9. Manufacturing Partner Experience
Building a biometric wearable is a substantially different project than anything else you’ve done before. Even if you’ve designed and built activity tracking wearables before, don’t underestimate the complexity of adding optical biometrics. It’s one thing to get some prototypes working in your lab. It’s a completely different thing to get that device manufactured at scale, and building up an optical system for quality and yield control.
You should chose a contract manufacturer (CM)/ original design Manufacturer (ODM) that has experience building biometric wearables at scale. They will have faced and solved many unforeseen challenges that other manufacturers have not. Ideally, the company providing your biometric sensor system should have a network of CM’s & ODM’s they’ve worked with and brought products to market with in the past.
10. Intellectual Property
Despite being a relatively new space, there is an extensive patent landscape in biometric wearables and high-profile companies are litigating in this space. This includes areas such as optomechanical designs, data processing, data assessments and visualization of wearable data. Make sure your team is well-versed in the IP landscape and your designs are free from any IP complications that could cause problems after the product is in the market.
How to Get Smart — fast.
When the viability of your product is on the line, knowing that you have a partner that has been through this hundreds of times before can give you peace of mind. But don’t just believe what we tell you. Interview a series of vendors. Read their white papers. Visit their testing facilities. Have full faith in your partner before you move forward, and the results will be obvious in your product’s success.
Originally published at valencell.com on October 12, 2016.