Compact cable protection at high speed on the dual-plane fluoroscope

Biomechanics research team relies on e-chain® in innovative fluoroscopy system

The Laboratory for Movement Biomechanics (LMB) at ETH Zurich is investigating the kinematics and kinetics of healthy, reconstructed and replaced joints. To this end, it has developed a two-plane fluoroscope that can track highly dynamic human joint movements in 3D space and record high-resolution, biplanar X-ray images at high speed. Two types of igus® energy chain are used to safely guide the many power and signal cables to the highly accelerating imaging units during fluoroscopy.

Energy chains P4.1 and E4.1 in the two-level fluoroscope of the LMB

What was needed: energy chain for guiding the power and signalling cables horizontally and vertically
Requirements: suitable for high accelerations and speeds, space-saving, low weight, long service life, minimal maintenance requirements
Industry: Medical technology, medical devices
Success for the customer: With P4-energy chain, the cables can be guided in the existing floor channels in a space-saving manner. Thanks to built-in profile rollers, the chains move with low friction even at high fill weights and speeds and require only a small amount of drive force. Our robust and easy-to-fill E4.1 chains provide vertical cable routing. The modular design of both e-chain® series offers flexibility for future customisation.

The bi-planar mobile X-ray system developed by the LMB is able to track highly dynamic human joint movements in 3D space. By utilising two overlapping image planes, the device overcomes the problems of out-of-plane errors, enabling accurate 3D registration of implant and natural skeletal kinematics. The design, in which the image intensifier and image source are separate, offers greater freedom of movement, both horizontally and vertically.

The new technology expands the basis for understanding and monitoring degenerative changes in the musculoskeletal system and the results of orthopaedic treatments and rehabilitation measures.

Problem

The development team was looking for suitable energy chains that would safely guide the many different power and signal cables of the motion track system. In order to accurately track the human knee during dynamic activities, the heavy carrier carriages with the imaging units have to accelerate rapidly. Finding energy chains that are suitable for such high accelerations was a challenge - especially in conjunction with the tight installation space. The chains had to be compact enough to fit into the 24 m long / 1.20 m wide / 0.15 m deep channels embedded in the laboratory floor.

Solution

The team sought advice from our e-chain® experts in Switzerland and came up with a solution that met all requirements: E4.56 chains for the vertical movement and a double chain solution with P4.42 chains for the two horizontally travelling carriages. We have developed the P4 series for applications with very high filling weights and speeds. Because the P4 is equipped with profile rollers, the drive force for moving the e-chain® is reduced to less than 25 %, and it also scores with quiet, low-vibration running and a long service life. As a modular construction kit, the system also offers the LMB team a great deal of flexibility for future customisations.
The vertical chains belong to the E4.1 series, which is suitable for almost all applications. It is also robust, low-noise and modular. It is also quick to assemble and easy to open. If cables need to be replaced or added, this does not require a great deal of effort.