Emily Newton, Editor-in-Chief, Revolutionized12.16.21
Medical-grade PCBs are the key to unlocking the future of our health and care. As the healthcare industry moves toward more advanced technologies and precise automation, highly capable medical robots will become the norm.
They won’t just be handling basic maintenance tasks, either. A trip to the doctor’s office or hospital may soon see you communicating and interacting with robotic office staff, nurses, and even makeshift surgeons. If that thought seems frightening, consider that most of those technologies will be so reliable, they can achieve things no human professional ever could. How are engineers designing medical-grade PCBs to meet the various requirements and conditions that exist in the field?
While your design process may look slightly different, the general makeup is the same. Here are some common steps in the PCB design and development stages for medical robots:
Step one is to gather all the relevant information and begin creating a drawing or schematic of the PCB. This is the initial planning phase, and you should take time to consider the type of board you will create, the materials, power requirements, and other critical factors—such as sequencing or split planes. Medical PCBs have remarkably complex specifications at times that must be adhered to.
It’s also important to understand the schematic is a general guideline. And while the required specifications must be met, some of the other elements may change as the work progresses. You may decide on a different design for component placement after realizing something doesn’t fit or isn’t as efficient as initially thought, for instance.
The enclosure is important because it protects the board from external exposure and shields it from other events. This is especially important for devices used inside the robot body. But because PCBs are often custom-designed, it means the housing needs to be built to match. Ample time is needed before development begins to choose the materials, design, and have the units shipped or produced.
Here are some things to think about when choosing a housing:
Component placement will take the longest during both the design and assembly stages. The layout must meet mechanical and electrical requirements, but also there’s a performance aspect—circuits must be grouped together. This may require moving components around the board and testing response or reaction times to determine optimal configuration.
Also, there should be alternative components available, besides the first-choice selections. Testing them for success and failure rates is important. When you find one not up to par, the alternatives will be there—provided you’ve tested them.
There are auto-routing tools available, but it’s important to understand their limitations. They don’t always follow optimal procedures, so it’s necessary to review power traces and sometimes manually reconfigure them.
Every PCB design and assembly process should take this into account, regardless of whether it’s an expected encounter or not. Proper spacing, trace width, ground planes, and signal-to-noise ratios (SNRs) are critical elements to build around.
Where are the major test points for the board before, during, and after assembly? More test points will help reduce errors and ensure the conditions are optimal during operation. What’s more, depending on the design and layouts chosen, every board is going to be different, so it’s necessary to evaluate proper testing each time a change or update is made. This is true for later product revisions, as well.
Thorough documentation will prove useful as you go, so be sure to record and note the testing procedures, locations, and results, and keep that information securely stored.
The final step in the process is, of course, to assemble the board. That includes the initial board development, solder paste stenciling and soldering, pick and placement for the components, reflow soldering, and any minor adjustments. A final inspection for quality control must always be honored. Then it’s time for the through-hole component insertions, if that’s relevant to the project.
Functional testing must be done to ensure the board, all components, and the product itself are in full working order.
There are many things to consider when developing PCBs to specifications, particularly when it comes to protecting them and building in resistance. For example, the assembly process must be planned, with thru-hole mounting and attached components or surface mounting for embedded and soldered components. The finished products are commonly used in medical imaging systems such as CT and CAT scanners, as well as heart rate, blood pressure, and glucose monitors.
Protecting medical-grade PCBs and planning safer designs calls for a full understanding of design specs, requirements, uses, and the final product. It may be necessary to create a surface-mounted board so the components are safe from how the device is being used and what conditions it is subjected to.
Most medical-grade devices are not going to be tossed into a volcano with extreme heat, but they will be in a sterile environment. They may be used inside the human body, and they could be exposed to other harsh conditions. Those scenarios and possibilities must be considered even at the initial design and planning phase.
Medical robots can be used inside the body and out. That will change and evolve as the technologies grow much more capable. Imagine nanobots, which enter the bloodstream of a patient to assess health, take measurements or fix an ailment. They can even be used in dentistry or for therapeutic purposes. The PCBs of those devices will be microscopic, so the design really needs to be tight.
Protecting the devices and components means considering many different scenarios. Some common factors to think about are:
Placing components and designing the layout of a PCB is a complex process, even for small DIY projects that require bots to follow lines or walls and avoid obstacles in their paths. One must meet the mechanical requirements of the project, group circuits for better efficiency and reliability, and ensure everything fits seamlessly on the board. And that’s just designing the board itself. Materials, soldering, assembly processes, and housing are all important, as well.
Understanding how to build printed circuit boards for medical applications and robots is just the start. Each application or bot requires a unique design, which means encountering several difficulties, such as the following:
Medical robots will be instrumental to the future of the health and medical industries. They will provide care and service efficiencies, handle increasingly sophisticated tasks and make up for labor shortages in the field—the AAMC projects a shortfall of 139,000 physicians by 2033. They come in various sizes and may take on advanced roles both inside and outside of the human body.
Medical-grade PCBs are essential to the continued use and advancement of these technologies. Printed circuit boards go inside the devices and systems and are used for many different things, namely to create an electrical circuit for proper activation. Protecting those PCBs, and the robots as a whole, is necessary to run the equipment optimally and keep patients safe. This will lead to continued advancements in the field of medicine.
Emily Newton is the editor-in-chief at Revolutionized Magazine. She regularly covers topics on robotics and automation as well as trends in the industrial sector.
They won’t just be handling basic maintenance tasks, either. A trip to the doctor’s office or hospital may soon see you communicating and interacting with robotic office staff, nurses, and even makeshift surgeons. If that thought seems frightening, consider that most of those technologies will be so reliable, they can achieve things no human professional ever could. How are engineers designing medical-grade PCBs to meet the various requirements and conditions that exist in the field?
Designing the Board
While your design process may look slightly different, the general makeup is the same. Here are some common steps in the PCB design and development stages for medical robots:
1. Create a Schematic
Step one is to gather all the relevant information and begin creating a drawing or schematic of the PCB. This is the initial planning phase, and you should take time to consider the type of board you will create, the materials, power requirements, and other critical factors—such as sequencing or split planes. Medical PCBs have remarkably complex specifications at times that must be adhered to.
It’s also important to understand the schematic is a general guideline. And while the required specifications must be met, some of the other elements may change as the work progresses. You may decide on a different design for component placement after realizing something doesn’t fit or isn’t as efficient as initially thought, for instance.
2. Select a Board Housing
The enclosure is important because it protects the board from external exposure and shields it from other events. This is especially important for devices used inside the robot body. But because PCBs are often custom-designed, it means the housing needs to be built to match. Ample time is needed before development begins to choose the materials, design, and have the units shipped or produced.
Here are some things to think about when choosing a housing:
- What is the ideal configuration of the enclosure—standing or lying flat?
- How many layers will the housing support?
- Will the board need to be trimmed or redesigned to fit?
- What are the drill hole ranges, and what securements are safe to use?
- What are the ideal trace thicknesses and spacing specifications?
- Are there clearances and portholes or will those need to be added?
- How much time is needed to produce or acquire extra units?
3. Situate Components
Component placement will take the longest during both the design and assembly stages. The layout must meet mechanical and electrical requirements, but also there’s a performance aspect—circuits must be grouped together. This may require moving components around the board and testing response or reaction times to determine optimal configuration.
Also, there should be alternative components available, besides the first-choice selections. Testing them for success and failure rates is important. When you find one not up to par, the alternatives will be there—provided you’ve tested them.
4. Route the Key Nets
There are auto-routing tools available, but it’s important to understand their limitations. They don’t always follow optimal procedures, so it’s necessary to review power traces and sometimes manually reconfigure them.
Every PCB design and assembly process should take this into account, regardless of whether it’s an expected encounter or not. Proper spacing, trace width, ground planes, and signal-to-noise ratios (SNRs) are critical elements to build around.
5. Create the Test Points
Where are the major test points for the board before, during, and after assembly? More test points will help reduce errors and ensure the conditions are optimal during operation. What’s more, depending on the design and layouts chosen, every board is going to be different, so it’s necessary to evaluate proper testing each time a change or update is made. This is true for later product revisions, as well.
Thorough documentation will prove useful as you go, so be sure to record and note the testing procedures, locations, and results, and keep that information securely stored.
6. Assemble
The final step in the process is, of course, to assemble the board. That includes the initial board development, solder paste stenciling and soldering, pick and placement for the components, reflow soldering, and any minor adjustments. A final inspection for quality control must always be honored. Then it’s time for the through-hole component insertions, if that’s relevant to the project.
Functional testing must be done to ensure the board, all components, and the product itself are in full working order.
Protecting the PCBs
There are many things to consider when developing PCBs to specifications, particularly when it comes to protecting them and building in resistance. For example, the assembly process must be planned, with thru-hole mounting and attached components or surface mounting for embedded and soldered components. The finished products are commonly used in medical imaging systems such as CT and CAT scanners, as well as heart rate, blood pressure, and glucose monitors.
Protecting medical-grade PCBs and planning safer designs calls for a full understanding of design specs, requirements, uses, and the final product. It may be necessary to create a surface-mounted board so the components are safe from how the device is being used and what conditions it is subjected to.
Most medical-grade devices are not going to be tossed into a volcano with extreme heat, but they will be in a sterile environment. They may be used inside the human body, and they could be exposed to other harsh conditions. Those scenarios and possibilities must be considered even at the initial design and planning phase.
Medical robots can be used inside the body and out. That will change and evolve as the technologies grow much more capable. Imagine nanobots, which enter the bloodstream of a patient to assess health, take measurements or fix an ailment. They can even be used in dentistry or for therapeutic purposes. The PCBs of those devices will be microscopic, so the design really needs to be tight.
Protecting the devices and components means considering many different scenarios. Some common factors to think about are:
- How will the device be used?
- What conditions will it be exposed to?
- Will the machine need to be cleaned or sterilized, and should the PCB be resistant to moisture?
- What materials are being used?
- What’s the circuit layout, and what components will be installed?
- Which assembly process has been chosen? Is it ideal?
Placing components and designing the layout of a PCB is a complex process, even for small DIY projects that require bots to follow lines or walls and avoid obstacles in their paths. One must meet the mechanical requirements of the project, group circuits for better efficiency and reliability, and ensure everything fits seamlessly on the board. And that’s just designing the board itself. Materials, soldering, assembly processes, and housing are all important, as well.
Medical-Grade PCB Design Challenges
Understanding how to build printed circuit boards for medical applications and robots is just the start. Each application or bot requires a unique design, which means encountering several difficulties, such as the following:
- Quality: Medical-grade PCBs are held to much higher standards that are non-negotiable and adhere to ISO 13485 requirements. This proves the devices are up to spec when it comes to changes in technology and regulatory requirements. The emphasis is on risk management and risk-based decision-making, as well as changes in the supply chain.
- Risk management: If a smartwatch or smartphone fails, a simple restart won’t hurt anyone. If medical-grade devices like a pacemaker or support technology go down, patients can lose their lives. Medical robots and devices must follow ISO 14971 requirements. The goal is to achieve a level of safety and reliability worthy of use in the field.
- Prototyping: Increasingly custom designs will be necessary for medical-grade PCBs and medical robots to handle more sophisticated tasks. A proper system of prototyping and design must be put in place to create effective products and test and implement them in safe, responsible ways.
- Bio-friendly materials: The materials used inside and out must be compatible with the human body, including the PCBs, components, and circuits. That’s especially true of devices that will be used indefinitely inside the body, like a pacemaker. This is vital for the items to be accepted and work properly for the sake of the patient.
- Fabrication and assembly: Circuit fabrication takes time, but smarter assembly means increasing output without compromising on quality. On some level, designs will need to consider this challenge because overly complex layouts complicate the situation and can result in failures. Much care and attention should be given in this step.
The Future of Medical
Medical robots will be instrumental to the future of the health and medical industries. They will provide care and service efficiencies, handle increasingly sophisticated tasks and make up for labor shortages in the field—the AAMC projects a shortfall of 139,000 physicians by 2033. They come in various sizes and may take on advanced roles both inside and outside of the human body.
Medical-grade PCBs are essential to the continued use and advancement of these technologies. Printed circuit boards go inside the devices and systems and are used for many different things, namely to create an electrical circuit for proper activation. Protecting those PCBs, and the robots as a whole, is necessary to run the equipment optimally and keep patients safe. This will lead to continued advancements in the field of medicine.
