Magnetic Resonance Pneumatic Stepper Motor With Multiple Concentric Shafts Output

Pneumatic stepper motors can be used to actuate MR safe robotics and other devices. Due tight space requirements inside the MRI scanner, it is useful combine several individual into a single device with an efficient shared actuator mechanism, called multiple concentric shaft pneumatic motor. The demonstrated “multimotor” prototype has six geared shafts driven by four cylinders controlled five lines. dimensions are ${\phi 58 \times 25}\rm \,{\text{mm}}$ (excluding shafts) maximum torque at 1.5 bar system pressure in range 56 114 Nmm. unloaded stepping frequency 50 Hz when using 0.3 m tubes drops 12 5.1m 15 N mm load on each shaft. positioning accuracy two steps most path planning algorithm needs 1.7 times as many separate single-axis motors. An examplatory 6-DOF manipulator design concept proposed motor requires order of magnitude fewer components than state-of-art robotic systems comparable kinematics. While multimotor offers significant advantages tube count, dynamic performance fundamentally poor, compromised coaxial output require thoughtful kinematic make effective use