Fundamental research

Ansys view of human spine

Biomechanics can be effectively explored via the appropriate use of finite element analyses.  However, commercially available softwares are ill adapted to process the intricacies that govern the mechanical behaviour of physiological tissue.  Thus, manipulation of the software's code, via custom coding, is required properly model a physiological system such as the spine.

Past projects from group members:

Biomechanical responses to load bearing: the theme of analyzing how loads (Newtons) and stresses (Pa) are distributed within our body.  Specifically, it was further focused on spine biomechanics by means of finite element modeling.  The model was coded to include an iterative growth algorithm enabling the spine to grow and respond to local stresses. The coded algorithm was based on in vivo studies that correlated bone growth to stress.  Once the model was validated, in silico simulations ensued and explored the impact of bone growth rates on the onset and pathomechanism of spine deformities. Several different spinal loading techniques were investigated in parallel.

Model of the human spine as it rotates slightly from front to back

The video above shows a static simulation of the lumbar spine with a simplistic force applied on L1 containing unique components used for the first time in 3D Simulations such as the Thoracolumbar Fascia. This is a result of the meshing process used which renders a computation time of less than 5 seconds for the lumbar spine and less than a 20 seconds when it contains the entire spinal components from T1 to S1.

Current projects:

Understanding the mechanisms that contribute to spinal stability, or lack thereof, is the global theme of the proposed research program. Spinal disorders and associated back pain currently represent an epidemic hindering productivity and creating a massive economic burden to developed nations. The presentation of a spinal disorder, mechanically, represents a flawed stability mechanism.  This fundamental research seeks to evaluate and quantify the role of passive tissues in spine stability.

Close-up of a section of the back of the human spine as it rotates slightly towards the front and back

Robotic Human Spine

Spinal injuries and disorders affect the majority of individuals and present a large economic burden on health and welfare systems. However, in many cases of lower back pain, there is uncertainty about the origin of the symptoms and the exact cause of pain is unknown.
The design of a robotic human spine is aimed at developing a model to understand the effects of spinal stability on the kinematics of the spine. The robotic spine is made up of analogue bones, cavities, and pneumatic muscles. Furthermore, the system is automated through a control system which is complete with position tracking sensors, pressure sensors, force sensors, and automatic valves. By studying the biomechanics of the spine model and the possible causes for spinal instability, this system aims to provide a foundation for researchers developing solutions to better understand and correct disorders.

Back view of the MBR human spine model with many wires attachedSide view of the human spine, as built by the MBR team

Assessing spinal stability through an integrated finite element model coupled with fascia, intra-muscular, inter-muscular, and intra-abdominal pressure effects.

Remarkable research efforts have been carried out to understand the mechanics of skeletal muscles and their contribution to spine stability. As such, part of this research is to build and validate an accurate finite element modelling procedure for skeletal muscles that would take into account intramuscular pressure build-up inside. In efforts of performing a spinal stability biomechanical studies, the ultimate goal of this research is to model the major muscles that attach to the spine in the same manner, model the soft tissues in that region, include intra-abdominal pressure, and properly integrate them in an accurate finite element model of the spine’s vertebral bodies.

Finite element model of spinal muscleClose-up view of finite element model of spinal muscle

Medical Device Design of a Novel Tool to Measure Pressures of Muscles Adjacent to the Spine

Back pain is a musculoskeletal condition that affects four out of five adults in Canada at least once in their lives. With such high rates of occurrence, and 80 to 90% of those suffering not knowing the exact cause, further research is needed to better diagnose and subsequently improve patient treatment. One known cause of back pain is spinal instability, a condition to which a formal diagnostic method has yet to be developed. It is, however, known that intra-abdominal pressure (IAP) plays a role in spinal stability. Therefore, it is hypothesized that spinal stability can be quantified given a tool to measure IAP. As such, research is being conducted at the Musculoskeletal Lab to develop and test a novel non-invasive IAP measurement tool for use in the analysis of spinal stability, and, in turn, back pain.

3D model of a portion of the back of the human spine

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