Why Shape Sensing is Poised to Displace Other Localization Technologies

Effective guidance and navigation of medical devices inside the human anatomy is a critical aspect in many procedures, but remains tricky with currently available solutions.

While the trend in technology tends to favor electromagnetic sensors, there are many reasons to be wary of their application in the clinical domain. Electromagnetic interferences are a powerful force that can throw off localization of a device and needlessly jeopardize the entire procedure.

Devices which utilize electromagnetic tracking solutions are at the mercy of the ambient conditions surrounding the operating theater, they only indicate location within a very small working volume, and some patients are even ruled out of associated procedures due to the presence of metallic implants.

Engineers are then forced to up their game and plan for any situation to guarantee the integrity of the procedure and protect patients. However, with the inability to always predict the surrounding environment or how other instrumentation residing in the same room will disturb the electromagnetic spectrum it becomes impossible to ensure consistency and accuracy over time.

Moreover electromagnetic sensors only track the location of a single point and can be difficult and cumbersome to integrate.

The most widely employed approach to visualize the position of catheters and other medical devices inside the body during surgical procedures is of course the use of Xray fluoroscopy.

Unfortunately, while the solution is both elegant and precise the exposure to quasi-continuous radiation is detrimental to patients and personnel.

Additionally, Xray images are only 2D and are often difficult to interpret.  Xray fluoroscopy also extends procedure duration and reduces the number of procedures performed per practitioner per year due to radiation exposure time-outs.

As an alternative technology, 3D shape sensing uses light as a medium and does not suffer from electromagnetic interference or any of the limitations mentioned above.

It is easily integrated to provide the exact shape and location of the entire length of a medical device throughout the entire duration of a surgical procedure without the use of Xray fluoroscopy.

The technology is based on the ability of fiber optic cables to sense strain and temperature continuously along its length and derive the 3D shape accordingly.