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Soft tissue artifact compensation model for accurate estimation of knee orientation

Applicant Aminian Kamiar
Number 137940
Funding scheme Project funding (Div. I-III)
Research institution Lab. de mesure et d'analyse des mouvements EPFL - STI - LMAM
Institution of higher education EPF Lausanne - EPFL
Main discipline Electrical Engineering
Start/End 01.10.2011 - 31.08.2012
Approved amount 51'335.00
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All Disciplines (4)

Discipline
Electrical Engineering
Surgery
Biomedical Engineering
Sport Medicine

Keywords (4)

Gait analysis; Knee function; Biomechanics; Soft Tissue Artefact

Lay Summary (English)

Lead
Lay summary

Gait analysis is mostly performed in biomechanical laboratories and uses mainly motion capture devices such as optoelectronic systems. Although accurate enough to reconstruct the motion properly, they are limited by the soft tissue artifact (STA). Then, the need of a suitable STA compensation technique is highly required for an accurate evaluation of segment kinematics. However, until now, there is no known efficient technique to compensate STA effects during gait. This can be explained by the lack of accurate and precise data for the skin and the bones during a gait activity. 

During our ongoing project supported by SNF, using the most advanced technologies from motion capture, bi-plane fluoroscopy and image processing, we have been successful to acquire synchronously relatively large amount of data from the skin and the bones. These data include the actual kinematics of the prosthetic knee and associated soft tissue kinematics of 80 markers apposed on the skin from 20 patients walking for many several minutes at different speed. It constitutes in our knowledge a unique database in the world.

Our objective is to extend the prior research to develop a new STA compensation method and to apply it on clinical data to improve the analysis and the interpretation of the outcomes used in gait analysisThis research will develop a STA compensation method based on accurate and precise experimental data of 20 subjects collected and analyzed during the ongoing project. These data correspond mainly to the trajectories of skin markers apposed on the lower limb and the poses (orientations and positions) of the knee F.I.R.S.T prosthesis (Symbios, Switzerland) implanted into the lower limb. 

This project will provide new complementary tools to reconstruct the 3D knee orientation accurately. It will offer to surgeons a truly objective outcome evaluation of patient treatment in orthopaedic surgery, rehabilitation and sports medicine. It will offer also the possibility to detect earlier dysfunctions and potentially avoid later failure, which will be beneficial for the patient and the cost-effectiveness of public and private health and wellbeing.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Error performances of a model-based biplane fluoroscopic system for tracking knee prosthesis during treadmill gait task
Barré Arnaud, Aminian Kamiar (2018), Error performances of a model-based biplane fluoroscopic system for tracking knee prosthesis during treadmill gait task, in Medical & Biological Engineering & Computing, 56(2), 307-316.
Assessment of the lower limb soft tissue artefact at marker-cluster level with a high-density marker set during walking
Barré Arnaud, Aissaoui Rachid, Aminian Kamiar, Dumas Raphaël (2017), Assessment of the lower limb soft tissue artefact at marker-cluster level with a high-density marker set during walking, in Journal of Biomechanics, 62, 21-26.
Soft tissue artifact distribution on lower limbs during treadmill gait: Influence of skin markers' location on cluster design
Barré Arnaud, Jolles Brigitte M., Theumann Nicolas, Aminian Kamiar (2015), Soft tissue artifact distribution on lower limbs during treadmill gait: Influence of skin markers' location on cluster design, in Journal of Biomechanics, 48(10), 1965-1971.
Soft Tissue Artifact Assessment During Treadmill Walking in Subjects With Total Knee Arthroplasty
Barre Arnaud, Thiran Jean-Philippe, Jolles Brigitte M., Theumann Nicolas, Aminian Kamiar (2013), Soft Tissue Artifact Assessment During Treadmill Walking in Subjects With Total Knee Arthroplasty, in IEEE Transactions on Biomedical Engineering, 60(11), 3131-3140.
Effect of markers attachment on soft tissue artifact and knee kinematics during gait
Barré A, ThiranJP, Jolles BM, Theumann N, Aminian K, Effect of markers attachment on soft tissue artifact and knee kinematics during gait, in Proceeding of 3D-AHM, Bologne, IT 1(1), 1(1).

Collaboration

Group / person Country
Types of collaboration
University of Rome “Foro Italico” Italy (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
University of Bologna Italy (Europe)
- Publication
- Research Infrastructure
- Exchange of personnel
Symbios, SA Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Industry/business/other use-inspired collaboration

Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Les secrets de la locomotion humaine Flash, EPFL Western Switzerland 2012

Associated projects

Number Title Start Funding scheme
120136 Reconstruction de la cinématique 3D du genou de patients durant les activités de la vie quotidienne 01.09.2008 Project funding (Div. I-III)

Abstract

Introduction.Gait analysis with accurate and reliable instrument is considered as the main tool in orthopedics for the objective outcome evaluations of lower joint functions after a medical or surgical treatment. Gait analysis is mostly performed in biomechanical laboratories and uses mainly motion capture devices such as optoelectronic systems. Although accurate enough to reconstruct the motion properly, they are limited by the interference coming from the human body itself and more specifically the soft tissue artifact (STA). Indeed, the main assumption in biomechanics is to consider the human body as a set of rigid body segments where the measurement of sensors or markers apposed on the skin will give a direct measure of the underlying bone. However, it is now well known that layers over the bones (muscles, soft tissue, and skin) create deformations related to the bones and then reduce the quality of the biomechanical analysis. Then, the need of a suitable STA compensation technique is highly required for the evaluation of patient treatment. However, until now, there is no known efficient technique to compensate STA effects during gait. This can be explained by the lack of accurate and precise data for the skin and the bones during a gait activity. This lack is mainly because of the difficulties to setup adequate experiments from commercially available instruments and to devise dedicated algorithms to process data and reduce the user interaction time. As the consequence, there is not enough gait data to be representative of the analyzed population. From such a dataset, it will comes possible to explain the limitation of developed STA compensation techniques, to develop new constraints on the skin data and then use bones data to validate them.During our ongoing project supported by SNF, using the most advanced technologies from motion capture, bi-plane fluoroscopy and image processing, we have been successful to acquire synchronously relatively large amount of data from the skin and the bones. These data include the actual kinematics of the prosthetic knee and associated soft tissue kinematics of 80 markers apposed on the skin from 20 patients walking for many several minutes at different speed. It constitutes in our knowledge a unique database in the world.Objectives.Our objective is to extend the prior research to develop a new STA compensation method and to apply it on clinical data to improve the analysis and the interpretation of the outcomes used in gait analysis. In order to reach this objective we aim:•To classify STA compensation methods detailed in the literature by comparing their results with gold standard data acquired in our project as lots of them use only synthetic data as validation.•To provide new constraints on bone movement by considering the patterns of orientation derivative (linear acceleration and the angular velocity of each segment), which give independent and complementary information, compared to markers trajectories. •To study the relation between the STA and the gait speed•To design a new STA compensation model by merging the results of the above methods in order to provide clinically useful metrics for bone movement and knee function evaluation.•To propose a clinically usable method where the tracking of bone movement using bi-plane fluoroscopy system is accelerated and the skin reflective markers used with motion capture system are clinically user-friendly.Approaches and methods.This research will be divided in two phases: the first phase will develop a STA compensation method based on accurate and precise experimental data of 20 subjects collected and analyzed during the ongoing project. These data correspond mainly to the trajectories of 80 markers apposed on the lower limb analyzed and the poses (orientations and positions) of the knee F.I.R.S.T prosthesis (Symbios, Switzerland) implanted into the lower limb. All of these data were acquired synchronously using a devised system composed of an optoelectronic motion capture system (7 cameras, VICON, UK) and two fluoroscopes (Philips BV Pulsera 300, Netherlands). In a second phase, the developed model will be extended to be useable into clinical analysis. It will be able to extract compensated clinical outcomes as well as errors associated with the STA. In the second phase, we will also develop a semi-automatic segmentation method used to track knee prosthesis with the bi-plane fluoroscopic system in order to allow surgeons to use this technique in their daily routine with acceptable user interaction time.Expected benefits.This project will provide new complementary tools to reconstruct the 3D knee orientation accurately as well as the extraction of improved clinical outcomes. Surgeons will be able to use this technique in their daily routine as well, with acceptable user interaction time. This will be of major importance, technically and medically, as in both cases, it will allow for a truly objective outcome evaluation of patient treatment in orthopaedic surgery, rehabilitation and sports medicine. It will offer also the possibility to detect earlier dysfunctions and potentially avoid later failure, which will be beneficial for the patient and the cost-effectiveness of public and private health and wellbeing.
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