Microfluidic CFD Applications: Medical Devices
Medical Test Strips
FLOW-3D simulation of dissolving
medicine in a medical patch.
Medical test strips used for rapid diagnostics and determination of relevant biomedical parameters have undergone considerable advances in recent years. Far from the conventional strips with absorbent fleece, new precisely-fabricated microchannels, with defined geometric structures, are now possible via Microsystems engineering. Proper geometrical design of these microstructures enables selective control of the capillary-driven flows. FLOW-3D flow simulation software can be used to optimize the designs of these strips.
Biotech Simulation Examples
Figure 1: Blood flow simulation
Figure 2: Shear thinning fluid in a
Figure 1: Blood, a non-Newtonian fluid, can be modeled using FLOW-3D through narrow arteries and veins to determine pressure balance and flow rates should there be a blockage. CFD simulation aids in circulation improvement for placement of stents, grafting procedure to eliminate blockage, and bypass surgeries.
Figure 2: FLOW-3D is used to predict transient injection forces on a plunger and strain rate for various solutions of shear thinning medical fluid. Medical fluids contain essential components that undergo high strain through shear thinning at the syringe-needle interface. FLOW-3D can be used to model various syringe-needle geometries and fluids to analyze the strain experienced by fluid in passage through the needle as well as the force generated on the plunger for automated injections.
Modeling Nasal Passages
Nasal drug delivery system, a promising non-invasive means of administrating drugs, poses numerous design challenges. If the spray particles are too large they tend to deposit in the anterior portion of the nasal cavity which reduces the effectiveness of the drug. If the particles are too small, a majority of the particles could pass directly to the lungs wasting most of the dose. For some drugs it is desirable to target a specific region of the nasal cavity like the olfactory region, which has a potential of delivering drugs directly to the brain. Designing a successful nasal drug delivery system requires optimizing various factors such as drug particle size, particle speed, spray angle, and nozzle insertion depth. Using FLOW-3D, the effects of the various design parameters on the system can be easily studied by running a series of simulations.
This CFD simulation shows the trajectory of spray particles through the nasal cavity. Particles are
colored by size, where red indicates the largest particles and blue the smallest. The simulation shows
that the smaller the particles are, the deeper they penetrate into the nasal cavity. The smallest
particles then exit the nasal cavity and go further into the respiratory system.