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EURAXESS

MSCA-COFUND-CLEAR-Doc-PhD Position #CD22-26: Spinal Cord Injury patient model – Damaged tissue and modelling

13/10/2022

Job Information

Organisation/Company
Université Gustave Eiffel
Department
TS2-LBA
Research Field
Engineering
Researcher Profile
First Stage Researcher (R1)
Country
France
Application Deadline
Type of Contract
Temporary
Job Status
Full-time
Hours Per Week
35
Is the job funded through the EU Research Framework Programme?
H2020 / Marie Skłodowska-Curie Actions COFUND
Marie Curie Grant Agreement Number
101034248
Is the Job related to staff position within a Research Infrastructure?
No

Offer Description

This PhD project aims at providing the improved multidisciplinary diagnosis tools which are required for decision making in Spinal Cord Injury (SCI) patient management, from transportation post-injury to rehabilitation. Between 250 000 and 500 000 injuries worldwide with spinal cord injuries (SCI) occur every year and 33% of such lesions lead to tetraplegia or paraplegia. SCI can occur resulting from traumatisms but also degenerative (e.g. myelopathies) or congenital (e.g. Chiari and syringomyelia) diseases. In addition, the occurrence of SCI degenerative pathologies grows with aging population. Among the various forms that SCI can have, cervical SCI are the most severe as they have major medical, psychosocial and financial consequences. Today, SCI patient diagnosis is limited by the time that can be dedicated to examination. This project will investigate the role of Cerebro Spinal Fluid (CSF) in improvement or alteration of SCI patients’ conditions. It aims at developing biomechanical markers associated with the interaction of CSF and meningeal tissues.

Clinical diagnostic and prognostic include cognitive assessment such as an American Spinal Injury Association Impairment score or International Standards for the Neurological Classification of Spinal Cord Injury (Marino et al., 2003; Waring et al., 2010) and imaging investigation when possible. The imaging investigation and acquisitions of SCI patients are limited to suitable time (capacity of the patient to lay still) on the table. CT scan is reported as the gold standard for SCI assessment. However, MRI, while more expensive and time consuming, enables structural investigation of the white and grey matter using specific sequence. Current diagnostic of SCI patients does not take into account the biomechanical tissue damage in which CSF flow, meningeal tissue and spinal cord structure take part. Current guidelines on traumatic SCI management states that early decompression surgery within the first 24 hours should be considered. Type and timing of the pharmacological treatment are also questioned in the early phase of the traumatic SCI but also in degenerative cervical myelopathy (DCM) and in congenital SCI. Development of an adapted rehabilitation is also part of the clinical experts choices. Thus, specific biomechanical markers for SCI patient assessment could be used by clinical expert in decision related to patient management.

The knowledge on the quasi-static behaviour of the structure to model (meningeal tissues) is necessary to develop FSI models. Material properties of the components of the canal have been described in the literature from white and grey matters (Bilston and Thibault, 1996; Karimi et al., 2017; Sparrey and Keaveny, 2011; Yu, 2019) with more recently association with axonal structure, to meningeal tissue (De Kegel et al., 2018; Jin et al., 2014; Shetye et al., 2014). Others components of the canal need to be characterized to enhance current canal simulation. While the micro-structure of the tissue is mostly described through its composition in collagen fibers and elastin, constitutive models usually use one or two fibers populations described by an orientation angle and a coefficient of dispersion. This is to say that mainly all fibers organization could be described by two populations while, especially on meningeal tissue, the full description of the micro-structure is missing. Thus, literature underlines the lack of integration and knowledge on collagen fibers mechanical behaviour into efficient constitutive models, especially.

Simulations of the canal have been reported even including FSI approaches (Cheng et al., 2014). However, such simulations mostly present a limited number of patient-specific canal fluid dynamics without describing association between morphology and CSF dynamics, and nor in the context of SCI except for Chiari and Syringomelia. No report of the canal simulation including damaged tissue mechanical properties neither specific simulation of the components of the canal. In the meantime, multi-scale simulations are reported using homogenization techniques for simulation of others physio-pathological mechanisms such as arterial tissue (Bianchi et al., 2019). An alternative approach to multi-scale modelling is the phenomenological approaches which consists in finding an adequate constitutive model of a material considering the micro-level behaviour of the structure. Such approach has been develop for the creation of an generic constitutive model (Zhang et al., 2019). Multi-scale modelling is then required for simulation of the micro-structure and mechano-biological phenomenon associated with SCI.

This PhD project will be divided into three parts:

• experimental investigation of damaged tissue

• improvement of the cervical spine simulation.

• Pre and post decompression surgery CSF flow simulation

Figure 1. Diagnostic canal morphology tools developed in Sudres’s PhD (3D morphological description (top left graphs), 3D ratio of compression (right corner figures).

Part 1 of the PhD program is the experimental test of damaged tissue after SCI in order to provide numerical simulations with material model enabling to accurately simulate such altered tissues. This concern the spinal cord and the meningeal tissue as well as ligament and nerves. This is a pre-requisite for the simulation of SCI condition and is based on recent meningeal tissue characterization (Evin et al., 2021; Sudres et al., 2021) and previous work from the laboratory (Fradet et al., 2016).

Part 2 of the PhD program aims at integrating the previously performed test within the actual existing model of cervical spine as well as testing by adapted sensitivity analysis the changes in material properties influence. Indeed, while constitutive models have been identified for meningeal tissue in quasi-static, integration to finite element model is missing.

Figure 2. SM2S simulation of the cervical spine including current state of ligaments and nerves simulation from (Beauséjour et al., 2022)

Part 3 of this PhD program is the simulation of pre and post decompression surgery on SCI patients. This will require adapted simulation of the CSF as well as SCI patient anatomy description (Sudres et al., 2020). As simulating CSF flow within the subarachnoidal canal, different approaches could be tested. Homogenization code could be considered to integrate altered tissues material properties.

Requirements

Research Field
Engineering
Education Level
Bachelor Degree or equivalent
Skills/Qualifications
  • At the time of the deadline, applicants must be in possession or finalizing their Master’s degree or equivalent/postgraduate degree
  • At the time of recruitment, applicants must be in possession of their Master’s degree or equivalent/postgraduate degree which would formally entitle to embark on a doctorate
Languages
ENGLISH
Level
Good
Languages
FRENCH
Level
Good

Additional Information

Benefits
  • High-quality doctoral training rewarded by a PhD degree, delivered by Université Gustave Eiffel
  • Access to cutting-edge infrastructures for research & innovation
  • Appointment for a period of 36 months based on a salary of 2 700 € (gross salary per month)
  • Job contract under the French labour legislation in force, respecting health and safety, and social security: 35 hours per week contract, 25 days of annual leave per year
  • International mobility will be mandatory
  • An international environment supported by the adherence to the European Charter & Code
  • Access to dedicated CLEAR-Doc trainings with a strong interdisciplinary focus, together with a Career development Plan
Eligibility criteria

Applicants must fulfil the following eligibility criteria :

  • At the time of the deadline, applicants must be in possession or finalizing their Master’s degree or equivalent/postgraduate degree
  • At the time of recruitment, applicants must be in possession of their Master’s degree or equivalent/postgraduate degree which would formally entitle to embark on a doctorate
  • At the time of the deadline, applicants must be in the first four years (full-time equivalent research experience) of their research career (career breaks excluded) and not yet been awarded a doctoral degree. Career breaks refer to periods of time where the candidate was not active in research, regardless of his/her employment status (sick leave, maternity leave etc). Short stays such as holidays and/or compulsory national service are not taken into account
  • At the time of the deadline, applicants must fulfil the transnational mobility rule: incoming applicants must not have resided or carried out their main activity (work, studies, etc.) in France for more than 12 months in the 3 previous years
  • One application per call per year is allowe
  • Applicants must be available full-time to start the programme on schedule (November 1st 2023)
  • Application rules are enforced by the French doctoral system which specifies a standard duration of 3 years for a full-time PhD together with the MSCA standards and the OTM-R European rules as follows
  • Citizens of any nationality may apply to the programme
  • There is no age limit
Selection process
Additional comments
  • The first step before applying is contacting the PhD supervisor. You will not be able to apply without an acceptation letter from the PhD supervisor.
  • International mobility : International mobility planned at the University of New South Wales (Australia).
  • Please contact the PhD supervisor for any additional detail on job offer
  • There are no restrictions concerning the age, gender or nationality of the candidates Applicants with career breaks or variations in the chronological sequence of their career, with mobility experience or with interdisciplinary background or private sector experience are welcome to apply
  • Support service is available during every step of the application process by email: clear-doc@univ-eiffel.fr
Website for additional job details

Work Location(s)

Number of offers available
1
Company/Institute
Université Gustave Eiffel
Country
France
City
Salon-de-Provence
Postal Code
13300
Street
304, chemin de la Croix Blanche
Geofield

Contact

City
Marne-La-Vallée
Website
Street
5, Boulevard Descartes
Postal Code
77454
E-Mail
morgane.evin@univ-eiffel.fr