Measurement of Impact Forces on Teeth and Jaw when Wearing Sports Mouth Guards

The objective of this project is to accurately measure the forces the teeth and jaw experience when subjected to impact. For this purpose piezoelectric technology (PVDF), which converts voltage to force and vice versa can be used to measure forces applied to teeth. A PVDF cable is calibrated and used for measuring force along with a control measuring device (PCB Piezotronics). The method involves wrapping the PVDF cable around a 3D home-printed, customized denture. The cable was chosen due to the fact that it allows for adequate fit between mouth guard and denture. Two masses, a baseball and 2 lbs - 3D printed projectile, were dropped from a height of 1m onto the denture with and without mouth guard. Results showed a significant force absorption by the mouth guard (more than 50% of initial impact force). After several trials, (n=10 for each group, baseball with and without mouthguard, as well as 2lbs), it was found that the impact shock absorption by the mouth guard ranged between 60-70%. Figure 1 shows the values at which the denture was impacted, with and without a mouth guard for baseball and 2 lbm cylinder. Finally, FEA Analysis was also used to show the regional stress and strain along the denture.https://scholarscompass.vcu.edu/capstone/1201/thumbnail.jp

Real-time visualization of magnetic flux densities for transcranial magnetic stimulation on commodity and fully immersive VR systems

Transcranial Magnetic Stimulation (TMS) is a non-invasive procedure that uses time varying short pulses of magnetic fields to stimulate nerve cells in the brain. In this method, a magnetic field generator (“TMS coil”) produces small electric fields in the region of the brain via electromagnetic induction. This technique can be used to excite or inhibit firing of neurons, which can then be used for treatment of various neurological disorders such as Parkinson’s disease, stroke, migraine, and depression. It is however challenging to focus the induced electric field from TMS coils to smaller regions of the brain. Since electric and magnetic fields are governed by laws of electromagnetism, it is possible to numerically simulate and visualize these fields to accurately determine the site of maximum stimulation and also to develop TMS coils that can focus the fields on the targeted regions. However, current software to compute and visualize these fields are not real-time and can work for only one position/orientation of TMS coil, severely limiting their usage. This paper describes the development of an application that computes magnetic flux densities (h-fields) and visualizes their distribution for different TMS coil position/orientations in real-time using GPU shaders. The application is developed for desktop, commodity VR (HTC Vive), and fully immersive VR CAVETM systems, for use by researchers, scientists, and medical professionals to quickly and effectively view the distribution of h-fields from MRI brain scans

Real-time visualization of magnetic flux densities for transcranial magnetic stimulation on commodity and fully immersive VR systems

Transcranial Magnetic Stimulation (TMS) is a non-invasive procedure that uses time varying short pulses of magnetic fields to stimulate nerve cells in the brain. In this method, a magnetic field generator (“TMS coil”) produces small electric fields in the region of the brain via electromagnetic induction. This technique can be used to excite or inhibit firing of neurons, which can then be used for treatment of various neurological disorders such as Parkinson’s disease, stroke, migraine, and depression. It is however challenging to focus the induced electric field from TMS coils to smaller regions of the brain. Since electric and magnetic fields are governed by laws of electromagnetism, it is possible to numerically simulate and visualize these fields to accurately determine the site of maximum stimulation and also to develop TMS coils that can focus the fields on the targeted regions. However, current software to compute and visualize these fields are not real-time and can work for only one position/orientation of TMS coil, severely limiting their usage. This paper describes the development of an application that computes magnetic flux densities (h-fields) and visualizes their distribution for different TMS coil position/orientations in real-time using GPU shaders. The application is developed for desktop, commodity VR (HTC Vive), and fully immersive VR CAVETM systems, for use by researchers, scientists, and medical professionals to quickly and effectively view the distribution of h-fields from MRI brain scans.This is a proceeding published as Vijay K. Kalivarapu, Ciro Serrate, Ravi L. Hadimani, "Real-time visualization of magnetic flux densities for transcranial magnetic stimulation on commodity and fully immersive VR systems," Proc. SPIE 10219, Three-Dimensional Imaging, Visualization, and Display 2017, 102190P (10 May 2017); doi: 10.1117/12.2262164. Posted with permission.</p