Smart wearables that collect vital data, such as fitness trackers, smartwatches, and medical-grade health monitors, are becoming more and more popular in the marketplace. They are, for the vast majority, made in China. As they start to be produced in very large numbers, they are following the model of other mass-market electronic products, and buyers need to be aware of the implications of that model before starting their fitness wearable development project.
The General Model of R&D vs. Assembly in China
Not many people know how wearable technology manufacturing (and other electronics such as smartphones and laptops) is organized in China.
Some companies do the R&D, designing the PCB, writing the firmware, and selecting components, and then sell the whole solution as “kits” to other companies. Let’s call them the R&D companies.
Those other companies buy the kits, then assemble and test the final products. We’ll call them the assemblers.
Assemblers do not:
- Have access to the source code.
- Decide what key components to use.
- Control the sensor integration.
All of these decisions are made by the R&D company.
So, when you get in touch with a manufacturer of a smartwatch, chances are, all they can do is offer relatively light customization. The software may have a slightly different feel. Maybe the casing will have a different shape. But it usually doesn’t go much deeper than that.
What Does That Mean When It Comes to Customization Options?
When made in China outside of big brands like Apple or Huawei, these products tend to be low-cost with intense competition between assemblers, and very little differentiation.
Any of the models will often look like many others that are made from the same kit. A kit typically includes:
- The electronic design and components.
- The firmware is loaded on the motherboard.
- Key peripherals like display, memory, and ports.
All these elements have been tested to work together. Customizations are possible, but they require additional payment, which goes mostly to the R&D company. Typically, you pay the assembler, who then pays the R&D company.
A real-world customization example
A German company orders a smartwatch with slight customization. They pay an assembler in Shenzhen who is using a kit from a Shenzhen R&D company. The assembler doesn’t have the source code or own the IP, and simply passes on requests (and payments) to the R&D company. In the end, the German company cannot get the source code, bill of materials, or key technical data, even if they forced the assembler to share everything they had.
The Extra Implications for Fitness/Medical Wearables That Collect Vitals Data
If you are developing a medical device or fitness wearable and want to build your own intellectual property, you need raw biometric data from the device’s sensors.
Look at the Apple Watch health functions:
- Blood oxygen
- ECG
- High/low heart rate notifications
- Irregular rhythm notifications
- Low cardio fitness notifications
- Sleep apnea notifications
All these rely on raw sensor data, which is then processed through a proprietary algorithm. To compete, you must create your own formulas, tuned for your niche application.
Without raw data, you can’t…
- You can’t develop your own analytics.
- You can’t run population-level data analysis.
- You won’t have a strong IP to attract investors.
- You may not be able to meet medical device certification requirements.
As noted earlier, assemblers do not have the raw data because they don’t have access to the source code.
Is It Impossible to Have Access to the Raw Data?
In our experience, only a small minority of companies will provide raw data.
Why?
- IP protection – Raw data access could lead to reverse engineering of their algorithms.
- Performance concerns – If raw data is compared to certified medical devices or even an Apple Watch, discrepancies might be exposed.
- Business model – R&D companies want to keep customers dependent on their integrated solutions.
By only providing processed or calculated values, they avoid scrutiny.
What This Means for Your Medical or Fitness Wearable Development Strategy
If you want to own your product and work based on an existing device, here’s what I recommend:
- Find and work directly with the R&D company.
- Negotiate raw data access upfront.
- Verify they can actually provide it (ask for sample data or API documentation).
- Lock IP rights into your contract.
The problem is that it’s quite difficult and it often is impossible.
If you have time & funding, and if you want a device unique to your company, there is an alternative. Start the product design from scratch with your own team or a “work for hire” design firm. That’s how you have full flexibility, provided your design architecture and your development contracts allow for it.
For a medical device in the EU or the USA, these steps are essential for achieving regulatory compliance.

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