Extrusion Process Requirements For Successful Catheter Development

The finish and quality of Catheters used in minimally invasive surgical procedures play a vital role in its performance with the end user. Several manufacturing dependencies such as the material used along with the extrusion process itself will decide the consistency and repeatability of catheters manufactured across the lifecycle of a catheter.

In this article, we explore the importance of involving extrusion engineers in the earlier catheter development stages.

The Importance Of Establishing A Correct Extrusion Process

With scores of decisions to be made in the design and development of a medical device, manufacturers (OEMs) usually rely on their own team of design and development experts. This is great as long as the entire manufacturing process is handled in-house. However, when the manufacturing is outsourced to a contract manufacturer, even very minor differences in how extrusion is conducted will affect the quality and performance of the entire medical device.

The extrusion process uses heat and customized dies to draw the material into a tube form with the desired thickness, diameter and determines important characteristics of the catheter’s performance such as:

• Push
  Catheters must possess the right amount of ability to push through the internal anatomy to get to their target sites as intended, a braided shaft lends better push and necessary torque compared to a non-braided one. The latest polymers (e.g. PEEK) and metal alloys (e.g. Nitinol) can offer variations in the characteristics of the catheter.
  
• Flexural stiffness
  As heat is applied to the selected catheter material, its physical properties can change and take on corresponding degrees of flexibility.  The rate and length of cooling also plays a part in determining the flexibility.
  
• Kink Resistance
  Stiffness and kink resistance are undoubtedly connected. So, the manner and temperature of heating and cooling will determine how far the catheter tube is kink resistant. At times the catheter sheath can be co-extruded onto the catheter tube, or it can be added using a slightly different material. This sheath can be braided (more push and torque) or coiled, depending on what characteristic you want.  

Striking the right balance in these properties can determine exactly what kind of catheter you will get, not just once, but on a consistent basis. Only experts in polymer science and experts in the field of materials behavior can work out the right balance in the achieving numerous catheter characteristics

Additional Important Catheter Characteristics

• Hydrophilic catheter coatings – for higher lubricity
• Multi-durometer segments – For better steerability and maneuverability
• Radio-opacity – For better real-time catheter trackability
• Wire options – Flat (lower flexibility) or round (greater flexibility)

Ensure a Consistent and Repeatable Extrusion Process with Quasar Medical

Quasar medical is a leading provider of technologies and services to medical companies, specializing in minimally invasive delivery and access devices. Our facilities are ISO 13485 certified, and we employ the latest technology with extrusion lines to provide tight tolerances and high-quality medical extrusions quickly and efficiently. Our extrusion team specializes in materials selection, and design optimization to facilitate push, flex and kink resistance for catheters.