One of the key objectives of Autocapsule was to demonstrate in vitro and in vivo a Robotic Capsule Demonstrator (RCD) capable to perform microultrasound array imaging and white light imaging of the GI tract, that can explore the GI tract via magnetic manipulation using. In this respect, all key subsystems of the RCD (wireless power transfer with telemetry, wireless image and data transfer, microultrasound imaging) have been successfully tested in the lab and in vivo. The complete RCD has been demonstrated in the lab. It has not been possible to demonstrate the fully integrated wireless RCD in vivo, because the reliability and the total volume of the final demonstrator do not guarantee a safe in-vivo experiment.
Another key objective was to demonstrate in vitro and in vivo an Implantable Capsule Demonstrator (ICD) capable to continuously monitor a specific area of the GI tract for several weeks through measurement of pH and temperature, fully untethered thanks to wireless power transfer and data transfer via a wearable external power transmitter and data receiver. To this aim, a custom multi-modal sensing ASIC for ISFETs, potentiometric, amperometric and temperature sensors was designed and tested. This chip was integrated in the design of variants of the second demonstrator (ICD2): a variant with wireless power transfer (WPT) including also the WPT ASIC reported earlier, and a variant using batteries. The second variant has been successfully tested in the lab and in vivo, exhibiting the required 30 days of fully untethered operation.
The project has enabled the advancement of a broad set of enabling technologies for implantable medical devices, culminating in the demonstration of robotic and implantable capsules and in the realization of second-generation wireless power and imaging subsystems ready for integration in future devices:
- A range of intelligent control strategies for magnetic manipulation within the Autocapsule system, encompassing closed-loop teleoperation, autonomous navigation, active stabilization has been implemented and experimentally validated.
- Integration of µUS technology into a small endoscopic capsule and into the robotic system has been achieved, enabling high-resolution subsurface imaging assessed in porcine models.
- Adaptable Wireless Power Transfer techniques compliant with SAR levels have been significantly advanced and demonstrated for both the RCD and ICD capsules, across different power levels, including a tri-axis active rectifier for RCD2 and a dedicated WPT ASIC for ICD2. These represent core technologies for a wide range of implantable medical devices.
- Wireless data transfer solutions have been developed for different power budgets and data rates, from energy-efficient low-rate telemetry in ICD2 to high-rate Wi-Fi HaLow links supporting real-time image transmission in the robotic capsule, establishing a versatile communication toolkit for future implantable medical devices.
Project results have been disseminated through peer-reviewed publications and international conferences in medical robotics and electronics. The work involved multiple PhD students and postdoctoral researchers, strengthening and expanding the project know-how base. Project IP has been generated and is under evaluation for potential protection.
