After working on numerous medical devices, we realized that catheter component manufacturing necessitates the precision of countless small details. In this blog, we describe the development process, materials, manufacturing technologies, and difficulties of complex catheters.
What is a Catheter?
Catheters are flexible tubes used in medicine for delivering and removing fluids from the body or monitoring bodily fluid levels. They can be placed into blood vessels, the heart, urinary tract, or any pathway in the body.
Three Layers of a Catheter
In catheter components manufacturing, we consider each layer a part of one designed system.
Inner Layer
The inner liner is our first step because it influences the performance of the catheter directly. We usually choose low-friction materials like PTFE to provide a smooth path for guidewires, fluid delivery, or other medical tools. From our experience, the lower the friction is, the easier the catheter becomes to deliver, particularly in case of prolonged or complicated interventions.
Reinforcement Layer
We consider the reinforcement layer to be the heart of the catheter. Depending on what kind of performance characteristics the catheter should have, we may use stainless steel braid, nitinol braid, or coil reinforcement. We know that just a minor change in the braid design or wire type may lead to a noticeable improvement in the torque, pushability, flexibility, or kink resistance.
Outer Layer
At the outer layer, we adjust the catheter’s feel and performance. With medical-grade polymers of various hardnesses, we are able to develop a catheter with enough rigid zones and flexible parts at the same time.
Catheter Development Process
Initial Concept and Design
All projects start with a discussion. Prior to starting any design, we take our time to learn the intended use of the catheter, its anatomy, and the required performance. We also consider manufacturing capabilities from the very beginning since an idea that seems perfect on paper may be impractical to manufacture. As soon as we define all requirements, we create our initial CAD design.
Prototyping and Designing
A prototype provides an opportunity to test something tangible rather than just talk about it. Components are manufactured, assembled, and tested. At this stage, modifications in terms of wall thickness, shaft design, materials, or tip geometry to increase flexibility and manipulation are made. Most catheter designs go through several versions until a prototype is created.
Testing, Verification, and Validation
With a working prototype, we begin to collect data. We test critical measurements, assembled components, and mechanical tests according to the specifications of the product. Should something not function as we anticipated, we return to the drawing board, revise our plans, and re-test. Based on our past experiences, this has always helped us find any issues while they are easy to address rather than after manufacturing has already begun.
Manufacturing and Production
Once the design process has been completed, we turn our attention towards repeatability. We manufacture all of the parts of the catheter, assemble the product, and conduct our inspections throughout the manufacturing process rather than at the end of it. This ensures that we manufacture catheters of the same consistent quality regardless of whether we are producing a pilot run or ramping up production.
Documentation and Traceability
All processes starting from receipt of materials up to finished product inspection are fully documented in order to ensure full traceability of each catheter back through the whole manufacturing process. During our long-term operation in this field, we have seen that documentation is not only an instrument for compliance with regulations but it also facilitates problem-solving and continuous improvement of the manufacturing process.
Critical Capabilities for Complex Catheter Manufacturers
Materials Expertise and Handling
The choice of materials determines the performance of the catheters in terms of flexibility, strength, and kinking. The materials that are used include Pebax, polyurethane, PTFE, and nitinol. This is why we handle and store them very cautiously.
Key Capabilities:
- Proper material storage condition
- Traceability of materials
- ISO Class 7 cleanroom assembly
Precision Braiding, Lamination, and Assembly
These catheters comprise several layers of polymers, reinforcements, markers, and tips. All the layers should be assembled accurately to ensure good performance.
Key Capabilities:
- Precision shaft braiding
- Thermal lamination
- Laser cutting of markers and hypotubes
- RF tipping, UV curing, and thermal bonding
- Inline dimensional inspection
Seamless Component Integration
The integration of tips, markers, pull wires, sensors, and metal components needs to be done very carefully.
Key Capabilities:
- Laser welding of metal components
- Adhesive dispensing
- Pull wire tensioning
- Tip forming and overmolding
Injection Molding for Tips, Handles, and More
Some catheters may need more than just the flexible tubing. Such additional elements provide enhanced functionality and usability.
Micro Molding for Catheter Tips
Soft tips can be manufactured using the micro-molding process to achieve seamless connection with the shaft of the catheter. It allows to keep the profile even while enhancing flexibility.
Insert Molding for Radiopaque Markers
Radiopaque indicators like platinum or gold rings can be incorporated into the tip or any other catheter component through the injection molding process to ensure safe and reliable placement.
Injection Molding for Catheter Handles and Hubs
Catheter handles and hubs are critical elements providing the necessary steering and delivery functionality. Our company produces functional handles and hubs with integrated inserts, textures, and other assembly details.
Types of Complex Catheters and Their Unique Demands
Implant Delivery Catheters
They should be able to carry devices such as stents, valves, or occlusions and deliver them into the body precisely. We specialize in loading, crimping, deployment testing, and integration of markers.
Balloon Catheters
Balloon catheters need proper inflation, deflation, and a strong connection between the balloon and shaft. We take care of the assembly, bonding, and testing, collaborating with experts in balloon forming.
Steerable and Deflectable Catheters
Such catheters are designed to perform difficult navigation tasks. We specialize in pull wire assembly, torque control, and transition for effective steerable and deflectable behavior.
Imaging Catheters
Imaging catheters like OCT and IVUS require precise alignment to produce the best image performance. We support shaft assembly, component integration, and concentricity/rotation tests.
Ablation Catheters
They require mechanical and electrical precision to perform therapeutic procedures. Our specialists concentrate on electrode assembly, bonding, insulation, and electrical tests.
Catheter Component Manufacturing Materials
| Material | Common Applications |
| Pebax® | Flexible shafts |
| Nylon | Structural catheter layers |
| Polyurethane | Soft outer jackets |
| PTFE | Low-friction inner liners |
| FEP | Heat-shrink processing |
| Silicone | Soft components |
| Stainless Steel | Braided reinforcement |
| Nitinol | Flexible reinforcement and steering |
| PEEK | High-strength structural components |
| Polycarbonate | Handles and hubs |
Things to Consider in Catheter Component Manufacturing
In our experience, the toughest part about catheter component manufacturing is usually not the initial design but being able to replicate it multiple times to maintain the same high standard of quality. We are mindful of the effects of tolerances, materials, bonding, and assembly because even small variations may impact function.
Even changes to a polymer’s characteristics could impact its flexibility and dexterity. By taking such things into account ahead of time, we can create a manufacturing process that will work well going forward.
Conclusion
Catheter component manufacturing takes more than just having good materials and equipment. From our point of view, the best catheter designs are those that involve cooperation of engineers, manufacturers, and medical device experts at an early stage. The combination of engineering expertise and manufacturing know-how can help avoid issues in the production process.
At MedCNCParts, we offer precision manufacturing services for high-tech medical parts. Contact us to discuss your next project.
