Health Care has been facing tremendous challenges to meet the demands of the patients. Health care desperately needs innovative solutions to solve these challenges, technology is there however, simply changes in the software world will not make much difference.
We need combination of hardware device and the software and major collaboration with Clinicians and health tech companies. We need medical devices that are portable, smaller, cheaper, and easy to use.
In this blog we will explore the process of building medical devices, and how it can solve real world problems.
Steps to build Medical Device
Here is a guide on how you can use an evaluation board to develop a proof of concept and, ultimately, design a PCB for a medical device:
1. Document all the Requirements (2-5 weeks):
You need to make it clear what problem the device is going to solve, who will use it? Docuemt all requirements, These requirements can be functional, electrical, mechanical, or safety-related.
You might already know the requirements and have a patent registered for the use case, you can focus on the proving the patent in Proof of concept, and make sure do not limit yourself to the only patent, in real life there are multiple supporting things needed to provide the seamless patient care in the hospital as well as at home.
2. Select an Evaluation Board (2 weeks) :
Evaluation Board is like a Template, it's starting point of your medical device. It is circuit with predefined components , such as a microcontroller, sensor, or signal processing device. An evaluation board is generally sold by MCU Companies, like STMicroelectronics, Nordic Semiconductor, Infineon. Choose a board that includes the major components you're considering for your design, For example your requirement is you need 32 / 128MB of memory to store the patient’s data, you need to select the right evaluation board, sometimes, a particular evaluation board does not have the components you’re looking for. In this case you can buy components connect them temporarily.
3. Develop Proof of Concept (4-6 weeks):
To prove the concept, you need these loosely connected parts to work together, This is where you program all together, we call it as Firmware. Firmware is the program written in C language which handles all the processing and the logic for your medical device. 60% of firmware should be written and proved on the evaluation board, yes, that’s right you do not need to design the PCB to start your firmware programming. You can loosely connect all components required to the evaluation board and develop the proof of concept. You're mainly testing the feasibility of the core idea, so don't worry about the size, aesthetics, or usability of the device. This step is often done using rapid prototyping methods.
4. Test and Analyze (2 -4 weeks) :
Once you’re sure that your version 1 firmware is ready for test, make an enclosure or use a ready-made enclosure to stick all components together and test the firmware like a real life test. Test your proof of concept to see if it meets the desired requirements. Analyze the results and make necessary changes in the design. This process may take several iterations until you have a design that performs satisfactorily.
5. Design Schematic
Once you are confident with the proof of concept, start creating a schematic of the circuit. A schematic is a symbolic representation of your circuit and forms the foundation of the PCB design. Once the schematic is ready, you can design the PCB layout.
6. PCB Design & Enclosure Design
Use a PCB design software to layout the components on the board. Place components such that signal traces are as short as possible. Always consider EMC(Electromagnetic compatibility) / EMI (electromagnetic interference) issues during the layout process. Consider the board size, number of layers, routing of traces, and positioning of components. Specifically, pay attention if you’ve multiple RF components on the board.
7. PCB Fabrication and Assembly
After the design is finalized, you can send it to a PCB fabrication house. They'll use your design files to create the PCB. After the boards are fabricated, they're sent back for assembly, which involves soldering components to the board. Overconfidence costs time and money, do not order more than 10 pieces of the PCB to be fabricated and assembled.
8. Verification and Testing
Once the PCB is assembled, the board needs to be tested to ensure that it functions as expected. This can involve applying power to the board and using a variety of test equipment to check voltages, signals, and overall functionality. Add an on board diagnostic test as part of your firmware, this is usually called OBDS (On Board Diagnostic Suite). This will help you to test each component independently, like Buttons, LCD, Sensor, Memory.
You can keep this OBDS as part of the production firmware but make sure firmware enters this mode only if it is manually triggered by the person and it’s secure enough.
9. Iterative Development (2-4 months)
When you’re planning for budget and estimations, include at least 2-3 revisions of PCB. Yes, it is a painful process, no pain, no gain. That is one of the reasons there are not many medical devices available to solve crucial issues. Also, Do not look for perfection, it’s part of the process. No one will design a perfect PCB on the first try. You'll likely need to iterate on the design several times, making modifications and corrections as needed, and repeating the testing and verification steps.
10. Certification and Compliance (2-6 months, you’ve less control here):
It's most important to remember that medical devices are required to comply with local regulatory bodies like HSA (Health Science Authority), IMDA in Singapore, CDSCO(Central Drugs Standard Control Organization) in India, FDA in the USA, and get the certification from them. Therefore, the design and testing process must also include steps to ensure the device meets all relevant regulatory standards. Initially, focus on one immediate market where you would like to explore, it’s practically impossible to make sure of all regulations and certifications in the first trial.
I hope you have a clear picture of steps involved in building medical devices. I would like to introduce the Medical Device Development Service at Delighteck. If you’re interested in building medical devices or you are already in the process of building it, and you need our help to accelerate, we’ll be happy to help, please send email to firstname.lastname@example.org or Whatsapp +65 89520272.