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

Biomechanics research team relies on e-chains in innovative fluoroscopy system

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

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

The bi-planar mobile X-ray system developed by the LMB is capable of tracking highly dynamic human joint movements in 3D. By using two overlapping image planes, the device overcomes the problems of out-of-plane errors and thus enables accurate 3D registration of the 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 to safely guide the many different power and signal cables of the motion track system. To precisely track the human knee during dynamic activities, the heavy support carriages with the imaging units have to accelerate rapidly. Finding energy chains that are suitable for such fast accelerations was a challenge - especially in conjunction with the tight installation space. The chains had to be compact enough to fit into the channels embedded in the laboratory floor, which are 24m long, 1.20m wide and 0.15m deep.

Solution

The team sought advice from our e-chain experts in Switzerland and came up with a solution that fulfils all requirements: E4.56 chains for vertical movement and a double chain solution with P4.42 chains for the two carriages travelling horizontally. We have developed the P4 series for applications with very high fill weights and speeds. As the P4 is equipped with profile rollers, the drive force required to move the e-chain is reduced to less than 25%. It also impresses with its quiet, low-vibration operation and long service life. As a modular system, it 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, quiet and modular, quick to assemble and easy to open. If cables need to be replaced or supplemented, this does not require a great deal of effort.