Development and implementation of an MR-safe encoder for pneumatic actuators of the MR-safe catheter robot for endovascular applications

Finished: 2022-01-18

MSc assignment

Aims and objectives

To design and develop a novel control strategy for the MR-safe pneumatic stepper motors mounted on the catheter manipulator of a robotic platform for endovascular interventions.

Background

Cardiovascular diseases are taking the lives of 17.9 million people every year, 31% of all global deaths, and this rate keeps increasing every year. Endovascular treatment is a safe, effective, minimally invasive method which has been highly promoted in clinical treatment of several cardiovascular conditions. Nevertheless, vascular intervention techniques take several hours and require the use of significant amounts of fluoroscopy resulting in extensive radiation exposure to the operator.  Although PPEs (personal protection equipment, such as x-ray gowns) can protect parts of the operator’s body from radiations, they are heavy and uncomfortable to wear. This results in an increased fatigue during long procedures which cause musculoskeletal disorders and affect the operations accuracy.  In this context.  remotely controlled vascular intervention robot has the following advantages: high precision, stability, and safety; clinicians can operate the robot from outside the operating room, so the radiation taken is consistently reduced. We are developing a robotic system for endovascular intervention and the next-gen, precise, safe, and reliable catheter robot manipulator needs to be developed.

Brief project plan

A major limitation of the current MR-safe catheter manipulator prototype is the lack of a feedback system in its pneumatic actuators. Such actuators are pneumatic stepper motors powered by an air compressor connected through long pneumatic tubes. Such configuration can cause occasional pressure loss which results in reduced motor force output and causes the motor to miss steps. Therefore, it’s clear that the absence of a feedback system that can take in account the state of the motors and feed the control system to compensate for the potential errors, negatively affects the safety and reliability of the platform.

The aim of this project is to address this challenge by designing and testing a novel MR-safe feedback system for our robot. This includes:

  • Design and development of MR-safe encoders;
  • Design and development of a control strategy for anomaly detection of pressure data using MR-safe pressure sensors.