Precise, small and non-magnetic
Piezo motors in medical technology. The numerous advantages of piezo motors are ideal for medical applications. In some diagnostic applications, especially in combination with magnetic resonance imaging (MRI) scanners, there is no alternative. The Swedish company PiezoMotor specializes in these motors.
Piezo motors feature compact dimensions and high precision – and therefore fulfil the requirements of diagnostic equipment and digital scanners, insulin pumps and surgical robots. The components that PiezoMotor has been developing for more than 20 years are based on the technology of piezoelectricity. A row of bimorph transducers is arranged so that they bend and expand when voltage is applied. When combined in pairs that are actuated alternately, they move an actuator stem in nanometer steps.
Voltage applied to the Piezo LEGS causes them to bend and extend or retract. This moves the driving shaft forward Photo: PiezoMotor
Smart concept in MRI robots and PET scanners
Users value the nanometer positioning accuracy of the motors, which deliver exact and reproducible results with ultra-high resolution. A linear motor powered by piezoelectricity, for example, provides the required nanolitre precision in a dosing pump. If required, the miniature motors are also available in a non-magnetic version, which qualifies them for use in MRI scanners. The Worcester Polytechnic Institute (WPI) used piezo motors to develop an MRI surgical robot that operated without interference even when exposed to the application’s magnetic field of several tesla. Applications for the robot now include, for example, precision thermal ablation of brain tumours, positioning of electrodes for deep brain stimulation in the treatment of Parkinson’s disease, as well as MRI-guided biopsy for prostate cancer diagnosis.
A micro dosing pump required a precise solution. The piezoelectric motor from PiezoMotor was the answer
Photo: Ginolis
Since the motors are vacuum compatible, they are also suitable for use in applications that involve radioactive substances, such as positron emission tomography (PET). A cyclotron is needed to produce the radioactive isotopes used for scanning and diagnosis of tumours and very small metastases. But not every clinic has the option of producing these isotopes, due to the complexity and high price of a cyclotron. As these isotopes decay rapidly their production has to be in the vicinity of the PET scanner. Vacuum-compatible piezo motors made the architecture of a cyclotron significantly simpler and the acquisition more affordable to the clinics. The experts at PiezoMotor support the development engineers with their knowledge and innovativeness. Together they analyse the requirements and options, in order to find suitable solutions.
