Catheters are widely used today for a range of medical functions. These thin tubes made from medical grade materials are essentially medical devices that can be inserted in the body for treating diseases or performing surgical procedures.
Through the modification of material or adjusting the way catheters are manufactured, it is possible to tailor catheters for cardiovascular, urological, gastrointestinal, neurovascular, and ophthalmic applications.
In this post, we’ll showcase the many types of catheters and how they are designed and manufactured today. We’ll guide you on what to look out for in a catheter manufacturer, plus highlight Interplex and our track record in this area.
Ready to get started? Let’s jump in.
Table of Contents
What Are The Different Types of Catheters?
Looking back through the history of medicine, rigid catheters made from reeds or onion stalks were used by ancient healers for insertion into the human body. However, the first medical usage of a flexible catheter was employed by none other than Benjamin Franklin in 1752 to treat his brother’s bladder stones.
Although most people think of catheters as the rubber tubes used to drain out urine in urinary tract conditions, various advancements in catheter design, technology, and manufacturing has enabled its use for treating a wide variety of medical conditions and as vital diagnostic procedures.
One such advancement is the smart catheter. What makes them different from regular catheters is that they contain “smart technology” allowing for the sending of signals along the catheter length to the distal tip in order to change it to a desired shape as it is inserted into the body. More on smart catheters later in this discussion.
How Are Catheters Made?
The manufacturing of catheters is an end-to-end operation that is being conducted by leading medical manufacturers such as Interplex Medical.
It all begins with the catheter design. Depending upon the medical procedure in which the catheter will be used, catheter designers take into consideration certain characteristics and functions – including a smaller or wider diameter, flexibility, steerability, the ability to handle greater torque or pressure, the need for extra coils, creating an atraumatic tip, modifications to allow for the addition of scopes, lasers, surgical instruments, and other medical devices – in relation to the internal anatomy of the human body part wherein the catheter will be inserted.
In the case of the catheter designers of Interplex Medical, they observe a hands-on engineering approach, going so far as to make careful observations of catheter use during operations by expert surgeons and clinicians. The valuable feedback obtained from these medical professionals help them to design catheters based on the characteristics that are mentioned above.
In the development of catheters, raw materials that are commonly used include the following:
How is a catheter made? Let’s take a look at the step by step process by which the most basic of catheters, namely the Foley catheter, is made. Most catheters are still made using this process, with added procedures for improved flexibility, the addition of special instruments, radiopacity for visualization through x-rays, CT scan, MRI and other imaging procedures, etc.
- A long, thin tube is made by pouring the raw material into a room temperature vulcanization (RTV) mold, which is in the desired shape and diameter of the catheter.
- The material is then cured with heat for a duration of 0.5 to 40 hours. Once it is cool, the tube is pulled out from the mold.
- One small opening is punched at the distal end of the tube.
- A thin band of cured latex is slipped by hand over the tube so that it forms a sheath over the opening where the opening was made.
- To keep the catheter in place inside the body, a balloon is created along the distal end of the tube. This balloon is formed by dipping the entire tube length in latex, thus creating an overcoat layer and bonding to the distal and proximal ends of the cured latex band.
- At the proximal end, the tube forks into two shorter tubes – one for the attachment of the urine bag and the other for injection of sterile water via a needleless syringe in order to fill the balloon.
Obviously, smart catheters are highly advanced and specialized than the lowly Foley. Smart catheters utilize a special braiding process that allows for fine fibre optic wires to traverse along the length of the catheter tube. These wires are part of a two-way communications network that sends electrical signals from a controller being operated by the surgeon or clinician to the length and distal end of the smart catheter. Using the controller, the medical professional can light up the interior of a vein, artery or other hollow vessel in the body and guide it through. He can also steer and maneuver the distal end through blocks, such as in atherosclerosis, or create additional coils so that the catheter can be passed through tight, convoluted blood vessels like in varicose veins.
Smart catheters also allow for the easy placement of stents. Through the lumen of the catheter, the surgeon can insert cautery or laser devices to burn away tumours and other obstructing masses. It also aids in the rapid induction of medications within a diseased.
Keeping in mind the many applications of smart catheters, among the considerations that catheter engineers take note of include:
- Greater user control over the smart catheter, including its flexibility, steerability, and maneuverability.
- Modifications in design and especially width/diameter of the catheter lumen to allow for the passage of specialized surgical instruments.
- The embedding of sensors, batteries and other power sources, lighting and imaging, and electrical circuitry.
- Embedded shape-memory alloys so that the smart catheter can change into specific coils or shapes during guided insertion.
- Greater strength, stability, and integrity of the length and lumen of the catheter during drug induction or the use of heat sources like lasers, which may cause degradation or deformation.
In recent decades, medical professionals have come to realise that minimally invasive procedures using catheters are better tolerated by the human body with much better treatment outcomes. With the continuing development of better and smarter catheters by catheter manufacturers, it will soon be possible to treat cancers and other conditions that are unreachable and/ or are difficult to treat through conventional surgical procedures as well as allow for the diagnosis of diseases in their early stages.