MedTec
Two-dimensional scanner for medical devices
A laser wave guide had to be positioned in a regular grid of scan points with 0.5mm spacing and +/-35µm accuracy. The design requirements were stringent: 5ms travel time between scan points (including time to settle), rest period at each scan point, an accelerated mass less than 1.5 grams, minimal drive volume and form factor, and battery operation. This design would thus require very light parts and backlash-free bearings that have minimal friction. Elliptec very successfully designed a direct-drive scanning stage with two of its highly dynamic and precise Elliptecmotors and customized the control software to reach each target position at maximum acceleration without overshooting. Hundreds of points can be scanned in a fraction of a second with complete standstill at each point.
Gas-sampling
In this hand-held analyzer, a precise volume of gas had to be acquired quickly for a volume- and time-sensitive analysis. Elliptec designed a battery-powered bellows sampler with one Elliptec motor. It acquires and discards gas samples fast and reliably and renders the analyzer more flexible and more economical than comparable portable units.
Autonomous navigation assistant for MRI guided interventions
Magnetic Resonance Imaging (MRI) scanners provide the best soft tissue contrast among medical imaging techniques and have few side effects on the human body. An MRI creates very strong electromagnetic fields within a tunnel where the patient is located. The fields and the somewhat claustrophobic tight space leave few options for a surgeon to accurately place external surgical markers on a patient without disturbing the image while he or she is being scanned. Providing doctors with means for remote interaction poses some unique technical challenges requiring special materials and shielding.
One such means is an MRI navigator built on Elliptec technology. The navigator has a height of less than 7cm and uses belt-drive slider system for positioning a laser pointer along the curved surface inside the MRI cavity without affecting the image quality. Four non-magnetic Elliptec motors are used for moving the laser pointer along the curvature and two motors for conical movements. Position encoders assured accuracy. The motors have been shown to work flawlessly in the strong magnetic fields while providing sufficient torque and speed for this in-situ marking application.
The device demonstrates that inexpensive, MRI-compatible navigators are possible with our piezoelectric motors. Heights of less than 5cm with lighter sliders and fewer motors are foreseeable. The device can be used inside the magnet bore of the MRI as well as for CT guided interventions.
