Pneumatic Stepper Motor

C04783: Precise MRI Safe Motor

Novelty:

A new motor design that can operate in the presence of a large electromagnet while maintaining the precision required for medical procedures.

Value Proposition:

Pneumatic actuators are widely used for both commercial and industrial applications due to their low cost, compact size, high power to weight ratio, reliability, and low maintenance. In some situations, these are preferred over the ubiquitous electric motors, especially when an air supply is readily available. The major limitation of pneumatic actuation is the reduced precision in controlled motion, thus making it unsuitable for use in surgical robotics. Alternative solutions in this field suffer from other drawbacks, such as the inability to operate in an MRI environment. This technology, however, provides a highly controllable pneumatic motor that is MRI-safe. Other advantages include: Does not affect image quality

Technical Details:

Johns Hopkins researchers have developed a pneumatic stepper motor that can be easily controlled for precise motion. Directional rotary motion of discrete displacement is achieved by sequentially pressurizing three ports of the motor. The motor assembly includes a motor, gearhead, and position encoder, allowing for open-loop step operation, as well as, closed-loop control with feedback from the built in incremental encoder. This invention was developed for medical applications to be used in conjunction with a robot that can precisely operate within the presence of MRI equipment. Therefore, it is constructed of nonmagnetic and dielectric materials to make it fully compatible with the MRI environment.

Looking for Partners:

To develop and commercialize the technology as a new motor to be integrated into devices in the Robotic Surgery Market.

Stage of Development:

Prototype

Data Availability:

Under CDA / NDA

Publications/Associated Cases:

IEEE ASME Trans Mechatron. 2007 February 1; 12(1): 98–106.