NanoShunt provides foundation to avoid transport tubes and complications of current shunt technology by Direct Dispersion and Disposal (DDD) of CSF in Hydrocephalus patients. DDD can avoid current shortcomings of VP Shunt.
A miniature device (connected to a catheter in the ventricle) when placed beneath the scalp, will convert CSF into ultrafine droplets under favorable temperature and pressure conditions which will then evaporate into vapor and leave the subgaleal space through a process of diffusion through the scalp and/or uptake from the rich capillary bed. This novel process would obviate the need for tunneling a catheter through the subcutaneous tissues of the neck and the entire thorax and into the peritoneal cavity.
Create a miniaturized device which will convert CSF into fine droplets (NanoMist) measuring 1-5 microns (ultrafine droplets).
NanoShunt proposes that ultrafine droplets created in an enclosed compartment will evaporate and diffuse through a membrane which approximates (or simulates) the physical properties of human scalp.
The thermodynamics and transport phenomena of CSF conversion model is presented here. The preliminary prototype is functioning as expected.
The transition from VP Shunt Technology to new NanoShunt process and product technology is shown below schematically.
Thermodynamics and Transport Modeling:
A schematic both thermodynamics and transport phenomena concepts of CSF disposal are highlighted below schematically. The modeling work is underway to aid in understanding and conducting prototype experiments.
Absorption in capillary bed
Diffusion through skin
Mission of NanoShunt Project:
Carry out laboratory prototype investigation to demonstrate that the device when placed under the scalp in a cadaveric specimen and connected to a closed fluid system will diffuse through the scalp when compared to a control setup without the device.
CSF Evaporation Thermodynamics Under Body Temperature Conditions (37 C):
The mist released from the implant will aerosolize in the implant cavity which is usually at the body temperature of 37 C. Although not well documented, the local pressure inside the implant cavity may be less than ambient. The graph below is d2-law plot of evaporation of droplets by Professor Brian Spalding. The data are for isolated droplets hanging in ambient temperature. The curves are shown for both 0% humidity and elevated humidity of 60% RH. Roughly, it is seen that below 10 micron droplets tend to evaporate in milliseconds. Any reduced pressure in cavity will further accelerate evaporation. The vapors produced transport downstream and get absorbed in capillary bed and diffuse through scalp and disposed of as sweat.
CSF Droplet Transport Model:
CSF two phase flow and subsequent evaporated vapors with in the cavity is being modeled by CFD computational model.