Smaller. Lighter. Innovative. Medical device designers often use these three terms to describe the trends driving their current and future product development. Of these requisites, smaller has become a fixation for next-generation designs, especially in the catheter business. The ability to micro-mold plastics and access tiny electronics are critically important for making components smaller.
Across the board, there are many good reasons for reducing the size of medical devices, such as requiring less space for storage and transportation. More importantly, micro technology promises lower healthcare costs through less intrusive and invasive procedures, leading to less recovery time for patients and reduced hospital stays. Less invasive surgical procedures offer many benefits such as less surgery trauma, lower post-operation risks and fewer patient clinical visits.
The push towards the micro in the medical device industry is also a significant economic opportunity. According to a recent report from BCC Research, the global market for medical device technologies is expected to grow from $810.4 billion in 2024 to $1.3 trillion by the end of 2029, at a compound annual growth rate (CAGR) of 9.8% from 2024 through 2029. As the industry continues to push toward smaller than ever devices, the ablation catheter sector is breaking solid new ground with industry partners.
Precision Device Assembly and Micro Fluid Dispensing Technologies
One such partner is the fluid dispensing technology supplier. As manufacturers produce smaller and smaller catheters, quality control becomes an even bigger issue. While many professionals in the quality business focus on physical precision in the production of these components, there is another critical piece of the equation. Medical device manufacturers must rely on precision jetting and micro fluid dispensing technologies to actually assemble these high-quality ablation catheters. Enter the fluid process engineer.
The Fluid Process Engineer
Fluid process engineers have a deep knowledge of fluids, viscosity and how to dispense each liquid to meet the most stringent of specifications. These engineers investigate touchpoints along the development path to troubleshoot and solve fluid assembly issues and integrate automated precision dispensing solutions that reliably and repeatedly place micro amounts of fluids onto a material or substrate.
Professionals in the fluid dispensing field are also laser-focused on high precision and quality control, such as the placement of microdots during the assembly of ablation catheters. Micro assembly applications can be very complex depending upon the type of fluid or adhesive and its viscosity. Once the fluid reaches the material or substrate, it must be able to restructure and recover to keep it from spreading and contaminating other components on the substrate.
The thixotropy of fluids is a major factor in successful micro-dispensing for a variety of applications. Thixotropy is a material property that depicts how some fluids and gels become less viscous when agitated but return to their original state over a period of time. Hence, expertise in fluid control is often invaluable to medical device manufacturers, who may not have this expertise in-house.
Micro-Dispensing Tech for Catheter Development
An ablation catheter is a thin tube inserted through a blood vessel into the patient’s heart. Catheter ablation is a minimally invasive treatment for fast heartbeats. The medical term for this is cardiac arrhythmia. Ablation is a technique used to strategically destroy abnormal tissue that could be causing an irregular heartbeat and restore proper function to the heart. This procedure is also known as cardiac ablation or radiofrequency ablation.
Contemporary ablation catheter designs are pushing the boundaries of material and manufacturing capabilities. A modern catheter that was once 2 mm in diameter is now 1 mm in diameter or smaller. These catheters can deliver pacemakers into the body and offer stenting, valving, suturing and pacing properties. These micro-sized devices also benefit from being placed close to the area in the body where they operate best.
Device manufacturers focus on capability, scalability and sustainability to make micro engineering catheters function well. The key aspect of a micro catheter is its thin walls and subassembly design, which plays a dynamic role as all components must flawlessly fit together. The use of rapid prototyping, micro plastic molding technologies and metrology technologies are all tools in the toolkit to ensure quality assurance.
During product development, fluid process experts step in at the critical and costly assembly stage. Dispensed adhesive microdots are 300-400 microns in diameter, which is roughly the thickness of 5-6 human hairs. To achieve these miniscule deposit sizes, sophisticated fluid dispensing technologies are necessary. Advances in fluid jetting make minimally invasive specialty catheters possible. In the future, precise technologies for dispensing small lines and dots at the micron level will be crucial.
Innovation Steps in
Based in East Providence, R.I., Nordson EFD is a veteran player in the fluid dispensing sector. The company’s PICO Nexus jetting system provides real time insights for data-driven process control and assembly. Designed for smart factory readiness, it connects fluid dispensing to Industry 4.0 efficiencies.
Users can control, manage and monitor jetting functions at the point of dispense via Industrial Ethernet protocols from a human machine interface (HMI) of their choice. The IIoT innovation lies within the machine’s ability to provide extreme precision and repeatability with its self-regulating calibration for improved valve-to-valve jetting performance.
Specifically, the solution’s micro deposit capability—as small as 0.5 nL—can be applied precisely at up to 1,000Hz continuously. These capabilities, coupled with micron (µm) level stroke adjustment, are ideal for sophisticated non-contact applications such as advanced cardiac catheter manufacturing.
The product’s web-based interface enables remote programming and on-demand inspection of fluid dispensing functions from a personal computer, laptop and other mobile devices, a dramatic boost for productivity. The controller is a compact design employing standard 24V and DIN-rail mounted plug-and-play technology to optimize production space utilization, especially where multiple valves are required. The solution also provides another rung of security for each system in the dispensing ecosystem.
Valve Technologies also Enable Precision
Needle valves are an essential tool for putting fine dispensing fluid lines and dots onto substrates. Ablation catheter manufacturing frequently requires microdots as small as 150 µm (0.15 mm; 0.006 in.) diameter. Nordson EFD has designed a line of valves that enable dispensing in tight spaces at more complex angles. These contact valves are different from non-contact valves like the PICO Nexus system because they must come in contact with the dispensing surface to apply a fluid. This makes them slower than jetting systems, but no less reliable or accurate.
For applications requiring deposits down to the fractions of a microliter, there is a line of valves that provide pneumatical operation and control. Catheter fabricators often choose this valve type because it dispenses consistent microdots as small as 0.18 mm (0.007 in.) diameter and is unaffected by entrapped air in fluids.
Nordson’s small gauge standard spray valves can apply a precise, uniform spray pattern up to 30% smaller than standard spray valves. The valve makes spray patterns as small as 3.3 mm (0.13 in.) and as great as 19 mm (0.75 in.) in diameter. A mini spray valve also provides the kind of precision needed for ablation catheter production with spray control in uniform patterns as narrow as 1 mm (0.04 in.) wide with accurate edge definition.
Hand-Held Fluid Dispensing Still Needed for Catheter Production
Automating the precise movements necessary to build an advanced ablation catheter is oftentimes impossible. Many highly skilled people perform the extremely precise movements necessary on these small workpieces.
To apply dispensing fluids manually, Nordon EFD’s specialized dispensers and chamfered tips are used to exact, repeatable micro-deposits on or between delicate surfaces. In the 33-ga size, the tips are capable of consistently making a 0.10 mm / 0.004 in. line of dispensed fluids. These solutions provide contamination-free and static-free performance and purity necessary for medical device manufacturing.
The Challenges Ahead
As engineers find success in new ablation catheter designs, other areas of the life sciences industry are looking to mirror those achievements. It is now routine to see smaller implantable devices for managing heart rhythm, pain and blood pressure. What these devices share in common lies within the build of the device. The ongoing challenge is to make ever more minute fluid deposits for their assembly as the requirement is for nanoliter and smaller deposit sizes. This is a significant change in manufacturing moving from microliters to nanoliters, with deposit sizes specifically at 4 nanoliters.
The long game for the development of medical devices like catheters is clearer, though. As global demand continues to rise, more efficient production approaches are necessary. Automated systems are integrating micro fluid dispensing technologies to keep up with this progress.
