In radiographic tilting beds the table upon which the patient is placed needs to be moved and controlled with smooth precision. In this type of application, servo motors and drives play a key role.
Fluoroscopes, angiograms and other radiographic applications can be achieved by obtaining a series of individual X-ray images that are then stitched together or animated to create increasingly detailed imagery that is suitable for expert medical analysis.
In addition to utilising advanced computer software to process the high-resolution radiography imaging, the table upon which the patient is placed needs to be moved and controlled with smooth precision – often over a wide range of angles and positions.
Servo motors and servo drives can be utilised to assure the safe and smooth movement of medical patients.
Reliable, precise movements
For upper and lower gastrointestinal barium enhanced studies, the table needs to smoothly tilt the patient from a horizontal position right up to a vertical position. This movement allows the liquid to flow through the patient’s digestive system while being captured in real time by the fluoroscopic X-ray source.
Each movement of the bed must be engineered to facilitate optimal operator use, to ensure maximum patient safety and to prevent extraneous patient movement during the examination.
The servo motors and drives solution
Each bed is equipped with six Parker SMB low-inertia brushless servo motors ranging from 3 to 10 Nm, with four of the motors equipped with a holding brake for additional safety.
In addition, six SLVD-N servo drives ranging from 5 to 10 A receive command signals from the controller, amplify the signals and transmit current to the servo motors to produce the precise range of motion, torque and positioning required.
The first servo motor controls the up-and-down motion of the table for easy patient access, enabling the table to be lowered to a minimum of 43 cm above the ground, the lowest of its category. The second motor allows the table to move transversally up to 30 cm outwards. The third and fourth motors meanwhile, control the oblique projections of the X-ray source. The fifth servo motor controls the movement of the column holding the X-ray source, allowing it to extend up to 180 cm from the table surface. The sixth and final motor controls the tilting motion of the table, enabling a full 90° range of motion for fluoroscopy and other radiography applications.
Working closely with experts from Parker, the manufacturer was able to improve the reliability and movement repeatability versus the previous solution used.
“We have chosen Parker because of their reputation, quality and the reliability of their products. Furthermore, thanks to Parker’s innovative technologies, it has been possible to constantly improve the performance of our machines. Partnering with Parker is profitable, in terms of both the technical and commercial support provided with the ultimate beneficiaries being medical staff and of course the patients themselves.”
Ing. Alessandro Biasini, R&D project leader, CAT Medical Systems
Learn more about servo motors here.
Article contributed by Michelangelo Matullo, automation account manager, Central South Italy, Electromechanical & Drives Division Europe.