Neuro And Ortho
Biomechanics Lab
CURRENT RESEARCH
Design and Fabrication of a Small in Vivo Biomechanical Testing Device
PROJECT MEMBERS: Thomas Zamorski (UG), Bridgette Saverine (UG), Veronica Schimpf (UG), Michael Tarquini (UG)
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Stretching of the brachial plexus nerve during child birth could result in brachial plexus palsey. At this time, only ex vivo testing has been completed to test the biomechanical properties of the brachial plexus nerve. Our goal is to measure the brachial plexus nerve in vivo to replicate real-life conditions.
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Final Rig Design
The final rig design consists of the following:
1. Locking pivot ranging from 0-90° to properly position the camera
2. Camera
3. Progressive Automations Linear Actuator http://www.progressiveautomations.com/mini-linear-actuator
4. Elbow hinge with full 360° of rotation for an accurate clamp angle
5. Adjustable rod ranging from 8-12 inches in length.
6. Load Cell
7. Clamp to attach the plexus
8. Adjustable locking hinge ranging from 0-180 degrees
9. Base to clamp the setup
Mechanism of Functional Recovery after Combinatoial Treatment Strategy by Studying Change in the Anatomical and Synaptic Plasticity (In Collaboration with Dr. Leone and Dr. Francis)
PROJECT MEMBERS: Sarah Townsend (UG)
Success of any treatment strategy depends on detailed understanding of the mechanism of recovery. Using immunostaining techniques we will first assess the neuroprotective and neuroregenerative effects of the scaffold+neurotrophins. One of the pathological outcomes of SCI is the formation of cavities of varying sizes in the injured spinal cord [39]. Since, neurotrophins protect neurons from degeneration we hypothesize to see a reduced cavity formation in animals transplanted with scaffold+neurotrophins. Axonal infiltration into transplant will be assessed by immunohistochemical presence of neurofilament (RT97) and growth associated protein (GAP43) responsible for axonal extension. To further assess regeneration, we will use retrograde tracing techniques to identify the location of the cell bodies that are projecting to or through the lesion site. A recent report by Courtine et al. suggest that significant functional recovery can occur after hemisection injury to the cord without the regeneration of direct projection from supraspinal areas, and can be mediated by reorganization of descending and propriospinal connections [40] . By counting the labeled neurons in the cord above the lesion (T7-T8) and motor centers in the brain stem (red nucleus) after injecting tracer in the locomotor circuits L1-2, we will determine if there is any descending or propriospinal axon growth within the transplant. Successful findings will help establish the efficacy of the bioengineered scaffold secreting neurotrophins in establishing anatomical connections while preserving spared descending pathways.
Body Weight Supported Treadmill Training Device
PROJECT MEMBERS: Babitha Tom (M.S), Thomas Zamokrsi (UG), Shania Shaji (UG)
Spinal cord injury (SCI) is a devastating and debilitating condition that affects an estimated 227,080 to 300,938 persons in the United States with approximately 12,000 new cases occurring each year. Current treatment strategies include activity based rehabilitation therapies, such as body weight supported treadmill training (BWSTT) that utilizes the uninjured descending pathways in incomplete SCI patients and spinal circuits below the level of injury in complete SCI patients. If the descending inputs are minimal or absent, recovery in walking over-ground is never observed in SCI patients. Since the amount of spared descending input strongly regulates the extent of recovery after BWSTT, combining transplantation treatment strategies that increase the number of descending inputs by inducing neuroprotective and regenerative environment around the injured spinal cord holds most promise to further enhance the functional recovery after BWSTT. Transplantation strategies using cells genetically engineered to deliver neurotrophins, which is a neuroprotective and neuroregenerative agent, limit spinal tissue loss, promote regeneration/sprouting of injured axons, bridge the site of injury and result in some functional recovery in animal SCI models. Clinical translation of these techniques poses several problems, including rejection and issues with regulation of release, requiring more invasive approaches with additional problems associated with potential rejection and regulation of release of bioactive compounds. To overcome these limitations, we propose using bioengineered scaffold poly N-(isopropyl acrylamide) – poly (ethylene glycol) (PNIPAAm-PEG), which has shown to be highly biocompatible and when functionalized to secrete a neurotropic factor can promote regeneration and functional recovery in a surgically induced SCI animal model. In the proposed study, we aim to further investigate the efficacy of this bioengineered scaffold secreting neurotrophins as an alternative to cellular transplants in a clinically relevant contusion SCI animal model. Furthermore by incorporating BWSTT in these animals, our collaborative group will for the first time report the combinatorial effect of scaffold+neurotrophins+BWSTT in a clinically relevant contusion SCI model. Successful findings from this study will help develop a unique tissue-engineering approach with promising clinical application in incomplete SCI patients. By adding other growth promoting agents to this bioengineered scaffold, future studies can explore the beneficial effects of the proposed combinatorial treatment strategy in complete SCI animal model.
Mini Torsion Biomechanical Testing Device
PROJECT MEMBERS: Joseph Loftus
The purpose of this study was to develop an economical, consistent, and repeatable torsion testing technique, including the device, for long bones affixed with compression plates. Compression plates are among the most commonly used fixation equipment in orthopedics. When focusing on forearm long bones, fracture of the radius and ulna are extremely common. It is estimated that these fractures of the radius and ulna make up 44% of hand/forearm fractures1. In pediatrics, it is estimated that 25% of all fractures are distal radius fractures2. A significant drawback in advancements of these orthopedic implants is a lack of industrial testing standard for biomechanical testing of the new iteration of these implants. Commonly used biomechanical tests include torsion, bending and combination to replicate real world scenario and the setup used for these tests costs hundreds of dollars. If a standard were to be adopted with an economical and reliable testing device, then time and money can be saved in the development and future research of the medical implants. This study details an economical and reliable custom-built torsion device with a torsion testing protocol that can be used to validate the efficacy of a newly designed forearm compression plate with various plate length, thicknesses and screw holes. These are the goals of our future projects.
Three Point Bending and Micro-CT Scans
PROJECT MEMBERS: Bridgette Saverine (UG), Shania Shaji (UG), Gabrielle Gehron (UG)
Following a SCI, there is a rapid loss of bone and muscle due to several factors including immobility and disuse. Two partially modifiable factors are lack of limb loading and normal muscle pull on bones. Declines in bone density and alterations in bone architecture increase fracture risk, and decreases in muscle volume increase risks of pressure sores, cardiovascular disease, metabolic syndrome, and diabetes. Our research includes biomechanical testing and CT scanning to determine biomechanical and morphological changes in bone after rehabilitation and exercise.
Mini Material Testing Machine
PROJECT MEMEBERS: Lindsay Stoy (UG), Thomas Zamokrsi (UG), Dylan Lawrence (G), Shania Shaji (UG)
Despite considerable research and improvements in obstetrical care, permanent Neonatal Brachial Plexus Palsy (NBPP) continues to occur in 1.1-2.2 out of 10,000 births and remains a regular challenge for the affected families and treating physicians [1]. The brachial plexus (BP) is a network of nerves that originate in the neck and run through the shoulder to the arm [2]. Stretching of the BP or avulsion of the roots can occur during birth when the infant’s shoulder impacts with the bony pelvis of the mother due to maternal (endogenous) forces as well as clinician-applied (exogenous) forces [2,3]. The effects of these forces on the BP are directly related to: magnitude, loading rate, surrounding tissue properties, and how the applied force is transmitted to the BP. Since in vivo measurements of the endogenous and exogenous forces, fetal shoulder deformation, and the response of the BP are difficult to assess during delivery, computational and physical models are used to simulate these events. However, a complete lack of biomechanical properties and data on the neonate BP limits the correct assessment of the risk of injury using these models. Thus, the goal of this project is to determine the biomechanical properties of the BP using a neonatal porcine model (piglets).
Computational Modelling of Forearm Bone Fracture Fixed with Locking Compression Plate
PROJECT MEMBERS: Tulsi Patel (UG)
The projected goal of this research is to redesign the conventional plate used for treatment of fractures caused by torsion. Previous literature offers experimental data for strength of bones tested under torsion; however, computational methods provide an efficient and less expensive technique of performing various tests to obtain the strength under different loading conditions such as compression, bending and tension. This research entails modeling and testing the radial bone along with the plate interphase and screws to achieve the optimum dimensions and overall design of the plate.