Monday, May 21, 2012

Designing catheters for cardiac procedures

Cardiac catheterization lab

Catheters are used in a myriad of cardiac catheterization procedures. In these procedures, a catheter is inserted into the femoral vein or artery through an incision in the groin and then advanced into the heart. The catheter is then used to complete the necessary procedure, such as deploy a stent or a valve. The catheter is removed from the body after completing the procedure.

Catheterization procedures eliminate the need for open heart surgery and offer various advantages such as faster implant time, reduced hospitalization, and faster recovery.  Some human factors considerations when designing catheters for such procedures are summarized below.

  • During catheterization procedures, physicians are fixated on the X-ray or fluoroscopic imagery. Fluoroscopy is an imaging technique that allows physicians to obtain real-time images of the heart structures during a procedure.
  • Physicians manipulate the catheter (using their hands) and look for feedback on the X-ray image. Because virtually all the visual resources of the physicians are dedicated to the imagery, they rarely look down at the catheter during a procedure.  So if the catheter has multiple buttons or controls on it representing multiple functions, these must be easily distinguishable to physicians by touch (i.e., tactile differentiation).
  • Designers frequently think that being able to visually discriminate between controls (i.e., using color or labeling) would be sufficient. This is inadequate in catheter design and has the potential to create user errors and confusions, especially when there are multiple controls on the catheter each depicting a unique function.
  • It is advisable to use redundant coding mechanisms such as size, shape, texture, and location when designing catheter controls so that users are able to differentiate between the controls through touch.
  • Often during these procedures, one hand of the physician is at the access site (where the catheter is inserted) and the other hand is on the catheter handle – torquing the catheter, manipulating the controls on the catheter and so on. Moving the hand away from the access site is undesirable as this has the potential to compromise the stability of the catheter. Therefore, it is important that the controls in the catheter handle be designed so as to facilitate a one-handed operation.

Photo credit Vuk at the German language Wikipedia, via Wikimedia Commons. 


  1. This was a great read about designing catheters for cardiac procedures! I came across your blog while I was reading about Bard catheters online because my doctor told me they were the best. I'm definitely happy I did because this was a very insightful and intriguing read, thank you for sharing with us Arathi!

  2. This was a very informative article. I have had multiple surgeries where I was hooked up to catheters and I just wanted to learn a little bit more about them. This site was very helpful!

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