Open Architecture Controller for a Catheter Insertion Surgical Robotic System by H. Bassan

Hansen Medical may be out of the game since Auris purchased it for the IP portfolio, but that does not prevent smart engineers from retrofitting the system for some further use. A prime example comes from Harmanpreet Bassan, published "Open Architecture Controller for a Catheter Insertion Surgical Robotic System".

"Sensei Catheter Robotic System is an FDA approved master-slave catheter insertion robotic system and had been used clinically for many years. In the original system, the surgeon controlled the tip of a proprietary guide catheter using a Master force-feedback device using live fluoroscopic imaging for catheter tip guidance. The Slave side of the robotic system includes a 4 degrees-of-freedom (DOF) passive positioning arm and a 10 DOF active catheter control module.

The steps to create an open-architecture controller required understanding of the original mechanical system and how various axes and other sensors in the catheter control module interacted to achieve the desired motions. Over the next few weekends, I dismantled the slave catheter module to its “bare bones” and got a thorough understanding of how the system was put together.

The slave catheter control module includes 10 DC servo motors, each equipped with redundant encoder feedback. The system also includes 6 strain gauge sensors that were used to indirectly measure the forces applied by the original system on the catheter tip. Modifications were performed on the internal electronics of the slave catheter module to access various feedback signals such that any commercial-off-the-shelf (COTS) motion controller and drive electronics would be able to achieve a fully open-architecture controller.

The open-architecture control electronics was divided into two controller chassis. One including 10 linear transconductance servo amplifiers with the needed power supplies and the second chassis with a modular motion controller running Linux with Real-Time Xenomai kernel. The modularity of the motion controller allows the addition of more interface axes cards in the future to expand the total number of axes. A haptic device would be a potential candidate for future addition into the same control hardware providing a tightly coupled master-slave robotic system."

Source: LinkedIn