For decades, catheter prototyping has been shrouded in mystique. Engineers outside specialized manufacturing facilities often believed that building a functional catheter delivery system required cleanrooms, million-dollar extrusion equipment, and complex manufacturing processes. This perception has created an unnecessary barrier to innovation, slowing down early-stage development and inflating R&D costs.
The reality? Modern catheter prototyping is democratized. With the right components, basic adhesives, and accessible fabrication techniques, R&D engineers can assemble functional catheter delivery systems on a standard lab bench. We're not talking about sterile, finished medical devices ready for clinical trials—we're talking about working prototypes for benchtop testing, design validation, and proof-of-concept demonstrations.
By the end of this guide, you'll know exactly where to source catheter components, how to assemble them using simple bonding techniques, and why both 3D printing and low-pressure injection molding have become essential tools for rapid prototyping of distal catheter features. More importantly, you'll understand that the biggest barrier to early-stage catheter innovation isn't technical capability—it's knowledge access.
Let's break down that barrier.
1. Understanding Catheter Shaft Options: Materials and Construction
The catheter shaft is the foundation of your delivery system. Understanding the available options—and where to source them—is the first step toward DIY catheter prototyping.
Catheter Shaft Materials: What's Available Off-the-Shelf
PTFE (Polytetrafluoroethylene / Teflon)
- Properties: Low friction coefficient, excellent for inner liners, chemically inert, rigid
- Typical use: Inner shafts, guidewire channels, low-friction interfaces
- Where to buy: Zeus Industrial Products, Vesta Inc., MicroLumen (accept small quantities for R&D)
- Cost range: $10-50 per meter depending on diameter
Polyurethane (PU)
- Properties: Flexible, biocompatible, good kink resistance, moderate pushability
- Typical use: Outer shafts where flexibility is prioritized, pediatric applications
- Where to buy: Putnam Plastics, MicroLumen, Chamfr marketplace
- Cost range: $15-60 per meter
Pebax® (Nylon block copolymer)
- Properties: Industry standard, variable durometer (40D to 72D), excellent balance of flexibility and pushability
- Typical use: Outer shafts for cardiovascular and structural heart delivery systems
- Where to buy: Arkema (material supplier), Putnam Plastics (fabricated tubes), available through Chamfr
- Cost range: $35-80 per meter for braided reinforced versions
- Pro tip: Pebax 72D braided tubes offer the best compromise for most cardiovascular applications
Silicone
- Properties: Ultra-flexible, poor pushability, biocompatible
- Typical use: Distal segments requiring maximum conformability
- Where to buy: Standard medical tube suppliers, even AliExpress/Temu for non-sterile prototyping
- Cost range: $5-25 per meter
Catheter Shaft Construction: Braided vs. Coiled Reinforcement
Single Lumen Tubes
- Simplest construction: just the base polymer
- Best for initial concept testing
- Limited pushability over long distances
Multi-Lumen Catheters
- Multiple internal channels (guidewire lumen + flush port, for example)
- Available as standard configurations from MicroLumen, Putnam Plastics
- Essential for complex delivery systems requiring irrigation or multiple guidewires
Braided Reinforcement
- What it is: Metallic wire mesh (usually stainless steel or nitinol) embedded between polymer layers
- Benefits: Superior pushability, excellent torque transmission, maintains lumen integrity under compression
- How to identify: Hold tube to light—you'll see the woven pattern through transparent sections
- Suppliers: Asahi Intecc, Fort Wayne Metals (sell components), Zeus/CathX Medical (fabricated tubes)
- Applications: Any delivery system requiring precise distal tip control over tortuous anatomy
Coil Reinforced Shafts
- What it is: Metal coil spring wound around or within the catheter wall
- Benefits: High flexibility with radial support, excellent kink resistance
- Typical use: Distal segments, neuro/coronary applications with extreme vessel tortuosity
- Suppliers: Fort Wayne Metals (micro-coils), Sandvik Materials (custom coils)
Comparative Guide: Choosing Your Shaft Configuration
|
Shaft Type |
Pushability |
Flexibility |
Kink Resistance |
Torque Control |
Typical Use Case |
|
PTFE single lumen |
★★★★ |
★★ |
★★★ |
★★ |
Inner shaft, guidewire channel |
|
Polyurethane plain |
★★ |
★★★★★ |
★★★ |
★ |
Flexible distal segments |
|
Pebax 72D braided |
★★★★★ |
★★★ |
★★★★ |
★★★★★ |
Cardiovascular outer shaft |
|
Pebax + coil distal |
★★★ |
★★★★★ |
★★★★★ |
★★★ |
Neuro, tortuous anatomy |
Catheter prototyping starter recommendation: The Protobrix U-Handle accommodates tube diameters from 6 to 24 French. For optimal performance, we recommend maintaining a 4 French diameter difference between inner and outer tubes. A typical starter configuration would be a Pebax 72D braided outer shaft (10Fr) paired with a PTFE inner liner (6Fr). This configuration covers most cardiovascular and structural heart applications and provides excellent push-pull independence.
2. Sourcing Catheter Components: The Modern Procurement Landscape
One of the biggest breakthroughs in DIY catheter prototyping is the emergence of accessible component marketplaces and the surprising availability of catheter parts through unconventional channels.
Specialized MedTech Component Marketplaces
Chamfr.com: The GitHub of Medical Device Components
- Digital marketplace connecting component suppliers with R&D engineers
- What you'll find: Catheter shafts, mandrels, luers, hubs, strain reliefs, guidewires, balloons
- Minimum order quantities: Often as low as 10-50 pieces (vs. 1000+ from traditional suppliers)
- Speed: Many suppliers ship within days
- Hidden value: RFQ (Request for Quote) feature allows you to describe your need without revealing your 5-year business plan. Suppliers respond in hours, not weeks.
- Expert insight: According to Damian Carr, founder of Eyedea MedTech Education and a leading catheter design expert, "30% of the suppliers I found on Chamfr were completely new to me after 20 years in the field."
Direct-from-Manufacturer Small Quantity Sources
Qosina Corporation
- Catalog shopping for medical components: Luer locks, connectors, stopcocks, valves, Y-connectors
- No minimums: Order single units or by the dozen
- Instant pricing: Online catalog with immediate checkout
- Perfect for: Proximal connections, hub assemblies, fluid management components
Nordson Medical
- Specialization: Hubs, hemostatic valves, manifolds, strain reliefs
- R&D programs: Accept small quantity orders for development projects
- Engineering support: Free application guidance
MicroLumen Inc.
- Custom extrusion capabilities: Multi-lumen tubes, medical-grade polymers
- R&D-friendly: Small production runs (100-500 pieces) accepted
- Lead time: 2-4 weeks for custom profiles
Protobrix / Protomed Component Stock Through our partnerships with AP Technologies and SG Medical, Protobrix maintains an inventory of commonly used catheter tubing in various diameters (6-24 French range) and configurations. While not all options are listed in our online store, we can often supply tubes for prototyping on short notice.
Available through Protobrix:
- Pebax tubes (various durometers and reinforcements)
- PTFE liners (single and multi-lumen)
- Polyurethane shafts
- Custom lengths cut to your specifications
Why this matters: Avoid 4-6 week lead times from traditional suppliers. Contact us directly at contact@protomed.fr to discuss tube availability for your specific application. We can often ship within days, not weeks.
The Surprising World of Amazon, AliExpress, and Temu for Catheter Prototyping
Here's where the catheter industry's best-kept secret lies: many catheter components are commodity items available through consumer marketplaces at a fraction of medical-grade supplier prices.
Radiopaque Marker Bands
- What to search: "Platinum iridium marker band catheter" or "radiopaque ring medical"
- Sizes available: 0.5mm to 3mm inner diameter
- Sources: AliExpress, specialized jewelry suppliers
- Price: ~$0.30-0.80 per piece vs. $3-8 from medical suppliers
- Quality caveat: Not certified for clinical use, perfect for prototyping and benchtop validation
Luer Lock Connectors
- Availability: Amazon, eBay medical surplus
- Specifications: Identical geometry to medical-grade versions (ISO 594 compliant)
- Price: $0.10-0.30 per unit vs. $1-3 from Qosina
- Use case: Early-stage assembly, proof-of-concept demonstrations
Guidewires for Compatibility Testing
- Source: eBay medical surplus, expired inventory sales
- Brands available: Abbott, Terumo, Boston Scientific
- Why it matters: Test your catheter's internal geometry with actual clinical guidewire profiles
- Caution: For benchtop testing only—never use expired medical devices clinically
Tubing and Basic Components
- Silicone tubing: Amazon, McMaster-Carr (industrial supplier with medical-grade options)
- Heat shrink tubing: For strain relief, available everywhere
- Small metal components: Springs, rings, bands from hobby electronics suppliers
3. Assembly Methods: The Glue That Holds It All Together
Here's the medical device industry's hidden truth: catheter assembly is fundamentally about adhesive bonding. Forget complex welding or mechanical crimping for early-stage prototypes—medical-grade adhesives create robust, reliable bonds for functional testing.
The Right Adhesive for Each Bond Type
Cyanoacrylate (CA) Adhesives: The Workhorse
Bostik 7452 Medical Grade Cyanoacrylate
- Bond type: PTFE to Pebax, polyurethane to nylon, general plastic-to-plastic
- Cure time: 10-30 seconds
- Bond strength: Medium to high (sufficient for benchtop testing and ex-vivo validation)
- Application: Inner/outer tube transitions, marker band attachment
- Biocompatibility: USP Class VI certified, ISO 10993 compliant
- Cost: ~$30 per 20g bottle
- Pro tip: Surface prep is everything—clean with isopropanol, let dry completely
- Protobrix partnership note: Available through our recommended supplier network
Bostik 7475 (Flexible CA)
- Special property: Maintains flexibility after cure—critical for catheter applications
- Ideal for: Polyurethane-to-polyurethane bonds where flexion occurs
- Cure time: 60 seconds
- Use case: Distal segment assembly where the bond must bend without cracking
- Advantage over standard CA: Lower modulus prevents stress concentration at bond lines
UV-Curable Adhesives: Speed and Precision
Bostik UV1540
- Bond type: Metal marker bands to polymer tubes, transparent plastic bonding
- Cure method: UV light (365nm) exposure—instant polymerization
- Bond strength: High
- Advantage: Precise placement, no squeeze-out, repositionable before UV exposure
- Equipment needed: UV flashlight ($30 on Amazon, 365nm wavelength)
- Medical certification: ISO 10993-5 and ISO 10993-10 compliant
Two-Component Epoxy: Maximum Strength
Bostik 2720 Medical Grade Epoxy
- Bond type: Luer locks to catheter proximal end, high-stress connection points
- Cure time: 24 hours at room temperature (accelerated at 60°C to 2 hours)
- Bond strength: Extremely high (survives pressure testing >300 psi)
- Application: Permanent proximal attachments, hub assemblies
- Biocompatibility: USP Class VI, ISO 10993 certified
Practical Assembly Techniques: Step-by-Step
Example: Attaching a Radiopaque Marker Band
Surface preparation
- Clean tube with isopropanol (IPA)
- Dry completely (30-60 seconds)
- Lightly abrade with 600-grit sandpaper if bonding PTFE
Marker placement
- Slide platinum-iridium marker band onto catheter shaft
- Position at desired location (typically 2-5mm from distal tip)
Adhesive application
- Load Bostik 7452 into 1ml syringe with 22-gauge needle
- Apply tiny drop (0.1-0.2μL) at marker-tube interface
- Critical technique: Let capillary action distribute adhesive under marker band
Cure and verification
- Wait 30-60 seconds for full polymerization
- Gently pull on marker—should not move
- If marker slides, bond has failed—remove with acetone, re-clean surface, retry
Example: Inner Tube to Outer Tube Bonding
Alignment
- Insert inner tube (e.g., 6Fr PTFE) through outer tube (10Fr Pebax braided)
- Ensure proper protrusion or recession (per design spec)
- Use mandrel wire to maintain inner lumen patency
Bonding jig
- 3D print or machine a simple alignment fixture
- Holds tubes concentrically during cure
- Critical for preventing misalignment that creates flow disruption
Adhesive selection
- Bostik 7452 for standard PTFE-Pebax bonds
- Apply circumferentially at junction
- Cure for 60 seconds
Validation
- Perform pull test (should withstand 2-5 lbs force without separation)
- Check for leaks by pressurizing lumen with saline
- Inspect bond line for voids
Pro Tips from the Field
"Less is more with adhesive application"
- Over-application creates rigid sections that become failure points
- Excess adhesive can occlude lumens or create rough external surfaces
- Aim for <0.5mm bond line thickness
"Surface preparation determines 80% of bond quality"
- Oils, dust, or moisture cause immediate bond failure
- PTFE and polyethylene require plasma treatment or chemical etching for reliable bonds (for prototyping, light abrasion with sandpaper works)
"Test to failure, not just to spec"
- Pull apart your assembly to understand failure modes
- Does the adhesive fail, or does the substrate tear? (Substrate tear = good bond)
- Understanding limits prevents failures during actual testing
Essential Equipment for Catheter Assembly
- UV lamp: 365nm LED flashlight (~$30)
- Precision syringes: 1ml luer-lock with 22G needles
- Mandrels: Stainless steel wire matching inner lumen diameter (prevent adhesive occlusion)
- Alignment fixtures: 3D-printed jigs for concentric tube assembly
- IPA (Isopropanol): For surface cleaning and degreasing
- Acetone: For removing failed bonds and cleaning tools
4. Advanced Prototyping: 3D Printing and Low-Pressure Injection Molding
The democratization of biocompatible 3D printing and accessible injection molding technology has revolutionized catheter prototyping. What once required expensive injection molding tooling can now be prototyped in hours or small-batch manufactured in days.
3D Printing for Custom Distal Features
Biocompatible 3D Printing Materials for Catheter R&D
Formlabs Surgical Guide Resin (Class I biocompatible)
- Certification: ISO 10993 certified for skin contact
- Properties: Rigid, sterilizable, excellent dimensional accuracy
- Use cases: Handles, hubs, rigid proximal components, injection molds
- Cost: ~$150 per liter (yields 20-40 components depending on size)
Formlabs Elastic 50A Resin
- Properties: Shore 50A durometer—simulates silicone
- Use cases: Atraumatic catheter tips, soft distal features, flexible seals
- Print quality: 25-50 micron layer resolution (more than sufficient for catheter prototyping)
Formlabs High Temp Resin
- Properties: Heat deflection temperature up to 238°C under load
- Special use: Injection mold manufacturing (withstands molding temperatures)
- Cost: ~$180 per liter
Stratasys MED610 (FDM alternative)
- Properties: Translucent, simulates polyurethane mechanical properties
- Use cases: Functional prototypes for mechanical testing
- Sterilization compatible: Autoclave, EtO, gamma radiation
Low-Pressure Injection Molding: Bridging Prototyping and Production
While 3D printing excels for rapid iteration, low-pressure injection molding offers a crucial middle ground between hand-built prototypes and full-scale manufacturing. This technology is now accessible to R&D labs—and we use it extensively at Protomed for catheter component development.
Holipress by Holimaker: Desktop Injection Molding
System Overview:
- Technology: Pneumatic low-pressure injection (0.5-7 bar) vs. traditional high-pressure (hundreds of bar)
- Mold compatibility: Works with 3D-printed molds (SLA resin, even some FDM materials)
- Material range: Medical-grade silicones, TPEs (thermoplastic elastomers), polyurethanes
- Cycle time: 5-15 minutes per part (depending on geometry and material)
- Cost: ~€5,000-8,000 system vs. €50,000+ for traditional injection molding equipment
Why This Matters for Catheter Prototyping:
Traditional injection molding requires machined aluminum or steel molds costing $10,000-50,000. Low-pressure systems like Holipress accept 3D-printed molds (€20-50 in resin), enabling:
- Rapid mold iteration: Design → print → inject in the same day
- Complex geometries: Internal threads, undercuts, thin walls
- True material properties: Unlike 3D-printed parts, injected components have production-like mechanical properties
- Small batch production: 10-50 identical parts for validation testing
Practical Application at Protomed: Threaded Atraumatic Tips
At Protomed, we use the Holipress system to create removable catheter tips with integrated threads:
Design advantage:
- 3D print the mold with internal thread geometry (M2.5 or M3 thread profile)
- Inject soft polyurethane (Shore 60A-80A) to create atraumatic tip
- Integrated threads allow tip to be screwed onto catheter shaft
- Benefit: Swap tips between tests without rebuilding entire catheter—perfect for testing multiple distal geometries with the same shaft assembly
Process:
- Mold design: CAD model with core/cavity split, thread features
- 3D print mold: Formlabs High Temp Resin (withstands injection temperatures up to 180°C)
- Inject material: Medical-grade polyurethane pellets (Pellethane, Tecoflex)
- Demold: 5 minutes cooling, unscrew thread core
- Finish: Trim flash, inspect threads, ready to use
Material properties comparison:
|
Property |
3D Printed (Elastic 50A) |
Injected Polyurethane (Shore 60A) |
|
Tensile strength |
2-3 MPa |
8-12 MPa |
|
Tear resistance |
Low (layers delaminate) |
High (homogeneous material) |
|
Durometer consistency |
±5 Shore |
±2 Shore |
|
Fatigue life (flex cycles) |
100-500 |
10,000+ |
|
Sterilization compatibility |
Limited (resin degradation) |
Excellent (EtO, gamma, autoclave) |
|
Surface finish |
Layer lines visible |
Smooth, mold-quality |
When to use each:
- 3D printing: Ultra-fast iteration (hours), complex organic shapes, initial concept validation
- Low-pressure injection: Batch consistency (10+ parts), functional material properties, threaded/mechanical features, pre-clinical testing
Common 3D Printed and Injected Catheter Components
1. Atraumatic Distal Tips
- 3D printed: Design freedom for tapered shapes, rounded profiles, integrated flush channels
- Injected: Threaded attachment interface, production-like durometer, repeatable geometry
- Material choice: Elastic 50A for quick tests, injected TPU Shore 60A-80A for validation
2. Implant Attachment Interfaces
- Test mechanical fit before committing to production injection molding
- Iterate designs in hours (3D print) or days (injection molded batch)
- Validate deployment mechanics with actual implants
3. Custom Hubs and Handles
- 3D printed: Ergonomic testing, feel the design in-hand
- Injected: Functional prototypes with integrated seals, o-rings, threaded connections
- Cost comparison: $2-5 in resin (3D print) vs. $15-30 per injected part vs. $500-2000 for machined prototypes
Practical Workflow: 3D Printing + Injection Molding
Week 1: Concept development
- CAD design of catheter tip geometry
- 3D print tip directly (Elastic 50A)
- Benchtop test: fit, function, basic mechanics
- Iterate design daily
Week 2: Mold development
5. Convert CAD to mold design (core/cavity split) 6. 3D print injection mold (High Temp Resin) 7. Trial injections to optimize process parameters (temperature, pressure, cooling time)
Week 3: Batch production
8. Inject 10-20 tips with validated process 9. Perform validation testing (tensile, flex fatigue, deployment) 10. Generate data for Design Input Document
Educational Resource: Damian Carr's "Catheter R&D Handbook" includes detailed sections on integrating both 3D-printed and injection-molded components into catheter assemblies. His hands-on workshops through Eyedea MedTech Education demonstrate these techniques with real components and live prototyping exercises.
5. Practical Example: Building a 10Fr Cardiovascular Delivery Catheter
Let's walk through a complete build from bill of materials to functional prototype, using dimensions compatible with the Protobrix U-Handle (6-24 French range).
Project: 10Fr Cardiovascular Delivery System Prototype
Design specifications:
- Outer diameter: 10 French (3.33mm)
- Inner lumen: 6 French (2.0mm) - maintaining 4Fr difference as recommended
- Working length: 1000mm
- Radiopaque marker at distal tip
- Female luer lock at proximal end
- Threaded atraumatic soft tip (removable)
Bill of Materials (BOM)
|
Component |
Specification |
Supplier |
Unit Cost |
|
Pebax 72D braided tube |
10Fr OD × 1000mm |
Protobrix/AP Technologies |
$48 |
|
PTFE liner |
6Fr OD × 1000mm |
Protobrix/SG Medical |
$14 |
|
Platinum-iridium marker |
2.0mm ID, 0.5mm wall |
AliExpress |
$0.60 |
|
Female luer lock |
ISO 594 compliant |
Qosina |
$0.80 |
|
Injected soft tip |
Shore 70A TPU, M3 thread |
Protomed (Holipress) |
$8 |
|
Bostik 7452 |
20g bottle |
Bostik distributor |
$30 (reusable) |
|
Bostik UV1540 |
10g bottle |
Bostik distributor |
$25 (reusable) |
|
Mandrel wire |
1.8mm stainless steel |
Hardware store |
$3 |
Total prototype cost: ~$95-100 (excluding reusable adhesives) Assembly time: 50-70 minutes (including cure times)
Assembly Sequence
Step 1: Distal tip preparation (15 min)
- Injection mold atraumatic tip (if not already done—5 min cycle time)
- Post-process: trim flash, inspect M3 threads
- Insert mandrel wire through PTFE inner tube
- Thread soft tip onto PTFE distal end (M3 threads mate with catheter shaft)
- Optional: Apply small amount of Bostik 7452 to lock threads (removable with acetone if needed)
Step 2: Marker band attachment (5 min)
- Slide marker band onto Pebax outer tube
- Position 3mm from distal end
- Apply Bostik UV1540 with syringe needle
- Expose to UV light (365nm) for 30 seconds
- Verify bond with gentle pull test
Step 3: Inner/outer tube assembly (15 min)
- Thread PTFE inner tube (with attached tip) through Pebax outer tube
- Adjust inner tube protrusion (tip extends 2mm beyond outer tube)
- Use 3D-printed alignment jig to maintain concentricity
- Bond PTFE to Pebax at proximal end using Bostik 7452
- Cure with mandrel in place to prevent lumen occlusion (60 seconds)
Step 4: Proximal luer attachment (10 min + 24hr cure)
- Trim Pebax outer tube to flush end
- Insert luer lock fitting 10mm into tube
- Apply Bostik 2720 epoxy circumferentially
- Allow 24-hour room temperature cure (or 2-hour at 60°C)
Step 5: Validation testing (15 min)
- Visual inspection: check bond integrity, marker alignment
- Push-pull test: manually verify smooth inner tube motion
- Kink resistance: bend to 90° radius, check for lumen collapse
- Guidewire compatibility: thread 0.035" guidewire through inner lumen
- Leak test: pressurize lumen with saline syringe, observe for leaks
What You Can Test Immediately with Your Prototype + U-Handle
Once your DIY catheter is assembled and mounted on the Protobrix U-Handle, you can begin generating validation data:
1. Pushability assessment
- Create a tortuous path using silicone tubing bent in 3D curves
- Measure push force required to advance catheter tip in 10cm increments
- Quantify force vs. distance curves
- Compare 10Fr vs. 8Fr configurations to understand size impact
2. Kink resistance characterization
- Perform 3-point bend test at multiple locations along shaft
- Document minimum bend radius before lumen collapse
- Compare to predicate device benchmarks
- Test effect of braided reinforcement vs. plain tubes
3. Marker visibility verification
- If you have access to fluoroscopy or X-ray (many universities and test houses do)
- Document marker position clarity
- Measure radiopacity vs. background contrast
- Verify marker doesn't migrate during push-pull actuation
4. Deployment mechanism validation
- If your catheter carries an implant prototype (3D-printed valve, stent, etc.)
- Test push-pull actuation for smooth deployment using U-Handle controls
- Record deployment forces and timing
- Validate inner tube independence (outer tube remains stationary during inner tube advancement)
5. Tip interchangeability testing
- Unique advantage of threaded tips: swap geometries mid-test
- Test rounded tip vs. tapered tip vs. side-hole tip
- Document navigability differences
- Identify optimal geometry without rebuilding entire catheter
6. Data for Design Input Document
- All these tests generate quantitative performance metrics
- Build tables, charts showing your device meets functional requirements
- Strengthen investor presentations and regulatory submissions
- Demonstrate you've validated core assumptions before expensive custom development
6. When to Move Beyond DIY: The Transition to Contract Manufacturing
DIY catheter prototyping is powerful for early-stage development, but it's not the end goal. Here's when you should engage a CDMO (Contract Development and Manufacturing Organization):
You're Ready for CDMO Partnership When:
You need custom extrusions
- Specific durometer transitions (soft distal, stiff proximal in single extrusion)
- Embedded radiopaque fillers (barium sulfate, tungsten)
- Complex multi-lumen profiles not available off-the-shelf
Animal testing is imminent
- Sterile devices required (EtO, gamma, autoclave sterilization)
- Full documentation trail for regulatory submissions
- GLP (Good Laboratory Practice) compliance
High-volume consistency needed
- 10+ identical units for design verification testing
- Statistical validation of manufacturing processes
- Batch-to-batch repeatability (CpK >1.33)
Design for Manufacturing (DFM) optimization
- Transitioning from hand assembly to scalable processes
- Injection molded hubs replacing 3D-printed parts
- Process validation per ISO 13485 requirements
But Until Then: The New R&D Workflow
Traditional catheter development (18-24 months):
- Concept → CAD design (2 months)
- Engage CDMO, negotiate contracts (1 month)
- First prototype quote and build (6-8 weeks)
- Receive prototype, test, identify issues (1 week)
- Modify design, request revision (4-6 weeks)
- Repeat steps 4-5 three to five times (6-12 months)
- Build DID based on limited test data (1 month)
- Commit to expensive custom development
Modern DIY-first workflow with Protobrix (8-12 months):
- Concept → CAD design (2 weeks)
- Source components via Chamfr + Protobrix tube stock (1 week delivery)
- Assemble prototype on lab bench (1 day)
- Mount on Protobrix U-Handle (30 min)
- Test, iterate, modify design—swap threaded tips without rebuild (2-4 weeks)
- Build robust DID with real performance data (2 weeks)
- Engage CDMO with confidence knowing your design works
The difference? Speed, cost, and data quality. You enter custom development having already proven your concept, not hoping it will work. You can tell investors: "We tested 5 tip geometries, 3 shaft stiffnesses, and validated deployment in tortuous models. Here's the data."
7. Learning Resources: Standing on the Shoulders of Giants
The knowledge democratization that's enabling DIY catheter prototyping didn't happen by accident. Visionary educators and industry pioneers have worked to make catheter design expertise accessible.
Damian Carr and Eyedea MedTech Education
Damian Carr is the founder of Eyedea MedTech Education, the world's first institution dedicated exclusively to advanced catheter design education. After building a private catheter prototyping lab and consulting with companies worldwide, Carr recognized a critical knowledge gap: engineers were repeatedly making the same costly mistakes because practical catheter assembly techniques were closely guarded secrets.
"The Catheter R&D Handbook"
- Comprehensive visual guide to catheter design, materials, and manufacturing
- Written to be accessible ("even an 11-year-old could understand it")
- Covers 70+ post-processing methods, material selection, and first-principles design
- Available through Chamfr and Eyedea website
Eyedea Workshops
- Hands-on, 2-day catheter design masterclasses held globally
- Live prototyping exercises with real components
- Material selection, bonding techniques, failure analysis
- Tailored to company-specific challenges
Chamfr Webinar Series
- "Concept to Prototype: How to Build a Catheter" (recorded sessions available)
- Features live catheter builds with critique from Damian Carr and industry experts
- Demonstrates real-world mistakes and how to avoid them
- Free access through Chamfr community
Key Philosophy: "Start with the simplest form possible. Don't over-braid, over-layer, or overthink before you've tested basic ideas."
Why This Matters for Protobrix Users
The knowledge ecosystem around DIY catheter prototyping makes the U-Handle even more powerful. You're not just buying a handle—you're gaining access to:
- A community of innovators sharing component sources
- Educational resources teaching proper assembly techniques
- Validation data methodologies that strengthen your DID
- Direct tube supply from Protobrix through AP Technologies and SG Medical partnerships
Want tubes for your project? Contact us at contact@protomed.fr to discuss availability. We maintain stock of commonly used configurations and can often supply within days.
This is the new standard of medical device innovation: fast, frugal, and fundamentally better.
Conclusion: The Democratization of Catheter Innovation
The medical device industry is undergoing a quiet revolution. Just as Arduino democratized electronics prototyping and GitHub transformed software development, accessible component marketplaces, biocompatible 3D printing, low-pressure injection molding, and knowledge-sharing platforms are democratizing catheter innovation.
The old barriers—cost, complexity, and access—are dissolving.
Today, an R&D engineer with a lab bench, $500 in components, a Protobrix U-Handle, and a weekend can build a functional catheter delivery system prototype. That prototype can generate real-world performance data. That data can inform a Design Input Document that secures funding and de-risks custom development.
Your Path Forward
Week 1: Source components
- Contact Protobrix at contact@protomed.fr for tube availability (6-24Fr range)
- Browse Chamfr for specialized components
- Order luers from Qosina, markers from AliExpress
- If you need custom distal features, explore Formlabs resin options or contact us about Holipress injection molding
Week 2: Assemble your first prototype
- Follow the techniques in this guide
- Use Bostik medical-grade adhesives for reliable bonds
- Don't aim for perfection—aim for function
- Mount your catheter on the Protobrix U-Handle (accommodates 6-24Fr)
Weeks 3-6: Test, iterate, learn, improve
- Create benchtop test models (tortuous paths, deployment fixtures)
- Collect quantitative data (push forces, kink angles, deployment success rates)
- Iterate rapidly—change shaft materials, adjust marker positions, swap threaded tips
- Test multiple configurations without rebuilding entire catheter
Weeks 7-8: Build your Design Input Document
- Compile your test data into performance specifications
- Document material selections with engineering rationale
- Include photographs, force curves, and validation test results
- Demonstrate you understand your device's performance envelope
Month 3: Engage custom development with confidence
- Approach CDMOs with a proven concept, not just a CAD file
- Negotiate from strength: "We know this design works, we've tested it"
- Accelerate manufacturing timelines because you've already de-risked the design
Resources Mentioned in This Guide
Component Suppliers:
- Protobrix / Protomed – Catheter tubes (6-24Fr), contact: contact@protomed.fr
- Chamfr.com – Comprehensive medtech component marketplace
- Qosina.com – Luers, connectors, valves (no minimums)
- Zeus Industrial Products – PTFE tubing
- Putnam Plastics – Pebax and polyurethane extrusions
- MicroLumen – Custom multi-lumen tubes
Adhesive Supplier:
- Bostik Medical Adhesives – 7452 (CA), 7475 (Flexible CA), UV1540 (UV-cure), 2720 (Epoxy)
Educational Resources:
- Eyedea MedTech Education – Workshops and "The Catheter R&D Handbook"
- Chamfr Webinars – Free prototyping tutorials and live builds
3D Printing:
- Formlabs Form 3B – Desktop biocompatible SLA printer
- Shapeways Medical – Print-on-demand service bureau
Injection Molding:
- Holipress by Holimaker – Low-pressure desktop injection system
- Available at Protomed for contract manufacturing services
Final Thought
Catheter innovation no longer belongs exclusively to large corporations with million-dollar R&D budgets. It belongs to every engineer willing to source components, learn assembly techniques, and test relentlessly.
Your concept deserves to be tested in the real world—not trapped in PowerPoint presentations waiting for funding. The tools, components, and knowledge are available. The Protobrix U-Handle gives you a professional testing platform. Partnerships with AP Technologies and SG Medical give you tube access. Bostik gives you medical-grade adhesives. Holipress gives you low-pressure injection molding capability.
The only question is: when will you build your first prototype?
Ready to mount your DIY catheter on a professional testing platform? Explore the Protobrix U-Handle →
Need catheter tubes for your project? Contact Protobrix: contact@protomed.fr
Want to learn hands-on catheter assembly? Check out Eyedea MedTech Education workshops →
Need components to start building today? Browse the Chamfr marketplace →
This guide is for educational and R&D purposes only. DIY prototypes are not medical devices and are not intended for clinical use. Always follow appropriate regulatory pathways and engage certified manufacturers for devices intended for human use.
