MRI Guided Surgical Interventions

The problem

Magnetic Resonance Imaging (MRI) can provide real-time visualization of anatomic structures of the beating heart and major blood vessels with circulating blood.
It is an ideal imaging modality for beating heart intervention as it can provide real-time functional information of valves and perfusion of the myocardium.
However, the surgeon has to reach inside the magnet, advance the delivery device and deploy the prosthetics.

Current Setup

Current Setup for a typical procedure inside MRI bore. The surgeon wears headsets to communicate with operator on the MRI console, who can modify the RT-MRI scan planes. Real-time MRI images are projected on large screen inside MRI room

User Input Sensor

Robotic setup with Innomotion robot and "user input sensor".

Robot Setup

Robotic setup with Innomotion robot and image guided delivery module.

A Solution

An MRI guided computer-assisted system for valve delivery. The system consists of:
- A robotic tool holder – a modified version of commercially available MRI robot.
- An image guided delivery module.
The workflow involves:
- Preparatory procedures of placing the trocar into the apex of the heart.
- Using cooperative control to guide and insert the delivery module that is attached to robotic holder, to trocar.
- Manipulate the delivery module under image-guidance to place the prosthetic value.

Results

An economic MRI compatible user input sensor was developed and its functionality tested.
Performance of the cooperative control using this sensor was evaluated.

Robot Setup

Mean percentage difference between images under different conditions and baseline image (Phantom only). (a) Condition 2: With robot only (b) Condition 3a: With robot inside bore and sensor at 1.0m (c) Condition 3b: sensor moved to 0.5m and (d) Condition 3c: sensor moved to 0.25m

User trials

Image captures of userr trials (Right) Peg in the hole task being perfomed using the MRI compatible user input sensor [video] (Left) Same task being perfomed using a graphical user interface [video]

The MRI-compatible robot for assisted transapical heart valve replacement is a collaborative effort with:

Ming Li, National Heart Lung and Blood Institute
Dumitru Mazilu, National Heart Lung and Blood Institute

Publications

A. Kapoor, B. Wood, D. Mazilu, K. Horvath and M. Li. MRI-compatible Hands-on Cooperative Control of a Pneumatically Actuated Robot, In Proceedings, IEEE International Conference on Robotics and Automation, 2009.