For my PhD I designed and built a device to simulate swallowing in the mouth. There is a whole thesis that details the processes of making it and then using it for testing.
In short the device consists of a silicone ‘tongue’ shown in profile below, which is compressed against a hard ‘roof’ in about 600 ms. This action is very fast and so a camera records the event at 1000 frames per second. The purpose of building this contraption was to quantify the speed and pressure in a fluid during this stage of the swallowing process. This information can be useful when designing fluids and fluid thickener products for people who have dysphagia (swallowing difficulties). As such the fluids that were tested in the device were a range of those typically given to dysphagia patients.
Here is a slo-motion video of the simulator executing a swallow. The bolus is pushed backward towards the pharynx, the area above your throat. The graphs shows the pressure recorded in the bolus at the fourth pressure sensor.
The simulator has two measurement systems, one for pressure and one for velocity. To measure pressure there are five sensors built into the palate which measure the fluid pressure indirectly.
To measure the speed of fluids during a ‘swallow’ I used a technique called Particle Image Velocimetry. This process tracks the position of many small particles shown in a 2D plane of a moving fluid to produce a velocity vector field.
You need a few frames of motion to make the calculations and with many frames you can capture this motion over time. In my case the particles in the fluid were actually small bubbles.
Personally, the project enabled me to learn a wide variety of skills including mechanical design, CAD, electronics, programming in C++ and MATLAB and the integration of a number of very different types of system into one complete device.
The oral simulator now resides in the UCL School of Pharmacy. After my PhD it went on to be used for a number of experiments which involved testing orodispersible film and tablet behaviour in the mouth (two methods of administering medicine orally).
PhD Thesis
discovery.ucl.ac.uk/id/eprint/10066883
Published Papers
A Mechanical Simulator of Tongue–Palate Compression to Investigate the Oral Flow of Non-Newtonian Fluids - ieeexplore.ieee.org/abstract/document/8301544
In Vitro Oral Cavity Model for Screening the Disintegration Behavior of Orodispersible Films: A Bespoke Design - https://jpharmsci.org/article/S0022-3549(19)30004-8/fulltext
How Do Orodispersible Tablets Behave in an In Vitro Oral Cavity Model: A Pilot Study - pubmed.ncbi.nlm.nih.gov/32660030