A Facile Magnetic System for Tracking of Medical Devices

Abstract

The largest disadvantage of modern day minimally invasive surgery is the required use of X‐ray or fluoroscopic imaging for locating or tracking medical catheters and tubes. The implications are increased costs and effort, limited availability for instance in less developed countries, and the cumulative exposure to contrast dyes and ionizing radiation are detrimental to health, especially in young patients and neonates with increased sensitivity. In order to reduce the use of X‐ray imaging and provide a wider accessibility, a facile magnetic system is proposed for subcutaneous medical device localization. It consists of a lightweight and flexible, biocompatible, and permanent magnet at the tip of the subcutaneous device and a sensing device to scan the dermal surface and locate the magnetic tip. The mechanical and magnetic properties of the magnetic tip are tailored to fit the requirements of the delicate catheter application. Evaluation of the tracking system using a 5 Fr magnetic tip resulted in a depth‐dependent position and orientation error of 0.75 mm and 3.7°. Additionally, a maximum placement depth error of 0.96 mm is achieved. Evaluation of the system in vivo revealed its practicality and accuracy as well as the influence of potential user errors.

Magnetic Catheter Placement in Neonates: A Handheld Solution to Radiation Exposure and Operational Delays

“…As discussed previously, [36] these maximum and minimum field values, shown in Figure 5a,b, are projected from both ends of the dipole and can be related to the location of the front and tail ends of the magnetic tip. The vector V (bold letters indicate vector quantities) connecting these two points represents the subdermal orientation 𝜽 of the catheter tip.…”

“…This composite can be molded into any shape and can sustain a high remanence field after it has been magnetized. The method for fabricating the magnetic catheter tip is described stepwise by [36] as well as the physical and magnetic characterization. Briefly, the magnetic tips are fabricated from a mixture of 5:1 (80 wt%) NdFeB: PDMS.…”

“…In our previous paper, [36] we introduced a facile magnetic tracking system as a potential alternative to existing catheter position evaluation techniques. We focused on the implementation of a magnet tip on an umbilical catheter together with a handheld Magnetic Sensing Device in an attempt to reduce X-ray exposure of neonates.…”