Veeshal H Patel, MD, MBA, Colin Brahmstedt, BS, Alex Balus, BS, Krista Camero, MS, Dillon Kwiat, Michael R Harrison, MD. University of California, San Francisco
Objective: Magnamosis is a magnetic compression anastomotic device for the gastrointestinal tract, with the goal of creating a leak-free anastomosis. It has thus far been successful in numerous animal studies and an ongoing human clinical trial. Since the magnetic rings can be placed and coupled using open, laparoscopic, and endoscopic or hybrid techniques, the surgeon needs assurance that the magnets have mated properly without intervening structures that might prevent a good anastomosis. Therefore, we have created a microsensor with wireless communication to be integrated into the Magnamosis device that will tell the surgeon the state of the magnetic coupling during the procedure.
Description of the technology: The core innovation is the use of an energy-harvesting Near Field Communication (NFC) integrated circuit (IC) to wirelessly power the implanted microsensor. Implanted batteries are not necessary. The integrated circuit board, multiple pressure microsensors, an accelerometer, and an antenna are integrated inside the polycarbonate shell around the ring magnet, thereby isolating all the electrical components and the magnet from the body.
Data from the pressure sensors is used to calculate that the two magnet rings are close enough together to ensure a secure anastomosis without intervening structures. The information is transmitted wirelessly to a transceiver that is capable of sending and receiving a signal. This device tells the surgeon that the magnets are properly coupled, thereby ensuring a secure anastomosis. An accelerometer provides orientation across three axes and an additional sensor measures internal body temperature. Postoperatively, intermittent readings can non-invasively monitor the progression of the coupled magnets through the bowel to expulsion.
Preliminary results: As this juncture, the implantable microsensor is prototyped and in the initial bench testing stage. Bench testing and simulations have demonstrated that we can indeed measure and gather this data using the various sensors. Additionally, through engineering redesigns, we have demonstrated the ability to safely insert the sensing systems into the device while maintaining its ability to remain biologically inert.
Conclusions/Future Directions: The immediate next steps will involve additional preclinical testing in an animal model to demonstrate both safety and effectiveness. This will permit us to evaluate the quality of the data at various locations and between various tissues throughout the gastrointestinal tract. Additionally, we plan to utilize the data to create a model to identify tolerances and safe ranges for forces and compression strength between the magnets, and therefore, between two walls of the stomach, small bowel, or large bowel.
The significance of the Magnamosis device and this sensor is twofold: first, it will provide the ability to apply new surgical solutions that were previously not feasible; second, it gives the promise of a new technology resulting in a physiologically and anatomically inert implanted biosensor that can provide valuable biological feedback without requiring a battery source.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 91167
Program Number: ET004
Presentation Session: Emerging Technology Session (Non CME)
Presentation Type: Podium