New catheter improves safety and precision in anesthesia

Whether for minor orthopedic or surgical procedures—often, it's sufficient to numb only a specific area of the body. But in these so-called local or regional anesthesias, the precise placement of the catheter is critical. Until now, this has required a great deal of experience, higher doses of anesthetic, or additional X-ray imaging—all of which come with drawbacks for patients.

A new project at the Institute for Circular Economy of Bio:Polymers (ibp) at Hof University of Applied Sciences aims to change that.

A new catheter tube visible under ultrasound is being developed in collaboration with ALPO Medizintechnik GmbH and the ibp. Medical support and a state-of-the-art ultrasound system are being provided by Kliniken Hochfranken.

The key innovation: By specifically adjusting the so-called acoustic impedance—a measure of how much ultrasound waves are reflected at the interface between different materials—the catheter becomes clearly visible in the ultrasound image. "This makes the otherwise invisible plastic tube easy to locate, without the side effects of contrast agents or X-ray radiation," explains Franziska Bauer, research associate at the ibp.

Pork loin as a test object

Initial tests were conducted using synthetic tissue models such as ballistic gel or phantom tissue. However, it quickly became clear that these materials caused interference in the ultrasound images.

The solution was found in pork loin: "Real muscle tissue provides realistic conditions and allows a valid assessment of visibility. In these tests, the new catheter proved its ultrasound compatibility—a crucial step on the road to medical approval," says Bauer.

To receive medical approval, the catheter must successfully pass a variety of tests and evaluations, including assessments of safety, performance, and clinical effectiveness. Once the final regulatory hurdles are cleared, there will be nothing standing in the way of its use in clinical practice. The advantages are clear: less anesthetic, fewer side effects, no radiation exposure—and a noticeable relief for medical staff.

Provided by Hochschule Hof - University of Applied Sciences