Vertebra by vertebra

Fast, high-resolution optical measurement of the human back, spine, and pelvis is accomplished with DIERS International’s formetric 4D contactless, radiation-free system with up to five camera units equipped with uEye industrial cameras from IDS Imaging Development Systems. A dynamic version and additional modules for determining the mobility of the cervical spine or gait analysis and leg axis measurement make the system a compact movement analysis laboratory.

The DIERS formetric product family provides answers to a wide range of clinical questions concerning the objective and quantitative analysis of body statics and posture. Deformities such as scoliosis and spinal malformations can be visualized, and a wide variety of progress checks can be performed – all while the patient stands in front of the system.

Based on the principle of triangulation, a light projector casts a grid of lines onto the patient’s back, which is recorded by a camera unit. Computer software analyzes the line curvatures and generates a three-dimensional image of the surface using photogrammetry.

The system provides a surface model of the back and a 3D model of the spine without the use of reflective markers. It reconstructs the spatial course of the spine and the position of the pelvis independently. The 4D technology (3D + temporal component) enables very high accuracy, increasing clinical informative value. The influence of small body movements during the examination on the result can be minimized by averaging a series of measurements. In addition, measurement sequences are possible for posture analyses and functional studies.

Holistic movement analysis

To be able to make examinations in motion, the company also has a dynamic version of the DIERS formetric system, DIERS 4D Motion. Using the latest projection and camera technology and specially developed software, as the patient runs on a treadmill, the complex interaction of the spine and pelvis can be measured and displayed in moving images. This enables an analysis of the vertebral body rotation and creates movement models of the spine.

Additional modules increase the range of applications up to a compact motion analysis laboratory. For example, the optional DIERS leg axis posterior and lateral camera modules for video-based analysis of the leg axis geometry can determine and document asymmetries in stance and movement sequence. The system software detects reflective markers applied to the patient and calculates movement patterns (dynamic) and angles (static and dynamic). In the case of foot and posture corrections, the effects on the leg axes can be directly displayed and checked.

With the additional Cervical Spine module, the mobility of the cervical spine can also be recorded three-dimensionally. The measurement data and asymmetries are displayed graphically for analysis. The measurement process takes place using a special head hood. The DIERS formetric 4D system requires an additional camera system for the Cervical Spine module.

As a high-end solution for holistic movement analysis at a running speed up to 30km/h, the DIERS 4D high performance Lab is also available. Its core technology is also the DIERS formetric 4D back and spine measuring device, combined with four fast, powerful IDS cameras for video gait analysis of the legs from all sides and a treadmill with integrated foot pressure measuring plate. All devices are combined for simultaneous measurements of the whole body.

With the integration of these and other measurement systems, it’s possible for the first time to view the complex biomechanical interaction in the human musculoskeletal system holistically. Contributing to this system are up to five IDS uEye CP industrial cameras per unit.

“We use the UI-3040CP as well as the UI-3240CP in our units. The USB 3.0 interface and the speeds achieved by both models convinced us,” explains Christian Diers, managing director/CEO of DIERS Int’l.

The uEye CP stands for compact power and is suitable for all types of industrial applications due to its high level of functionality with comprehensive pixel pre-processing and its small size of 29mm x 29mm x 29mm. The internal 120MB image memory for buffering image sequences also qualifies it for multi-camera systems. The USB 3.0 cameras enable a high data rate of 420MB/s, low central processing unit (CPU) load, and easy integration. Users can choose from many modern complementary metal-oxide semiconductor (CMOS) sensors from manufacturers such as Sony, CMOSIS, e2v, and ON Semiconductor with a wide range of resolutions.

The model UI-3040CP-M-GL Rev. 2 enables excellent image quality even in low light or when shooting fast-moving subjects. The integrated IMX273 global shutter CMOS sensor from Sony’s Pregius range scores particularly well for its image quality, high sensitivity, and wide dynamic range. With a resolution of 1.57MPixels (1,448px x 1,086px) at 3.45µm pixels, it achieves 243 frames per second. This makes the camera suitable for classic industrial applications such as surface inspection, but also for detailed image evaluation in medical technology.

The UI-3240CP-M-GL Rev. 2 is a powerful industrial camera with the e2v 1.3MP CMOS sensor. This sensor is one of the most sensitive sensors in the IDS portfolio. Besides its light sensitivity, the camera is distinguished by the sensor offering two global and rolling shutter variants that can be switched during operation, providing maximum flexibility for changing requirements and environmental conditions.

Both models allow for easy integration into the customer application, as Christian Diers confirms: “We use the IDS SDK to integrate the cameras into our software. The added value for us lies in the simple verification of the correct functioning and integration of the cameras into our system. Environmental settings, such as brightness or contrast, are controlled by the IDS software package.

DIERS Int’l GmbH
https://www.diers.com

IDS Imaging Development Systems
https://www.ids-imaging.us