ICP Monitor Client Josh Medow Advisor Willis Tompkins Team Members Lacey Halfen - BSAC Jess Hause – Leader Erin Main – Communicator Peter Strohm - BWIG

Outline Shunt Purpose and Function Project Inspiration Failure & malfunctions Existing ICP Monitors Components of Device Design Requirements Internal Casing Specifications Membrane Designs Bottom and side configurations Biocompatible Materials Design Matrix Future Work

Shunt Purpose and Function Regulation of ICP Hydrocephalus Excess cerebrospinal fluid causes increased ICP Mental disability, death Drain excess cerebrospinal fluid away from head Incidence rate of 1% (

Inspiration for ICP Monitor Shunt failure rate 50% failure rate in first 2-3 years Shunt malfunctions Invasive diagnosis Surgery & Shunt Tap Noninvasive diagnosis Physical Exam MRI / CT Scan (Joshua Medow, MD)

Existing ICP Monitors Battery Battery in chest but needs replacement Large in size Expensive Finite power supply Direct Electrical Power Electrical contact exposed through skin External power supply Infection prone

Overall Design Components Noninvasive method to measure intracranial pressure Effective power transmission across skin MEMS pressure transducer internally Signal transmission to external receiver

General Design Requirements Accuracy & Reliability Minimal electronic drift Lifespan ≈ 20 years Materials Biocompatible MRI – no ferrous materials Pressure ranges Average: 10 – 15 mmHg Gauge range: -30 – 100 mmHg Generate pressure waveform

Internal Casing Specifications SKULL 2 mm 1 cm 2 cm 2.5 cm 5 mm

Design Schematics Cont. MEMS LL

Solid Works Drawing

Membrane Designs Bottom Membrane Side Membrane

Materials Polyimide tubing for case Strong Biocompatible Chemical resistant Silicone or Teflon membrane Can be made thin and flexible Biocompatible Chemical resistant (

Membrane Design Matrix Biocompatibility (0.2) Feasibility (0.3) Damage Susceptibility (0.3) Sensitivity (0.2) Total (1.0) Side Membrane 10 (2.0) 5 (1.5) 8 (2.4) 6 (1.2) 7.1 Bottom Membrane 10 (2.0) 7 (2.1) 4 (1.2) 8 (1.6) 6.9

Future Work Material compatibility testing Membrane testing Encasing MEMS device and inductor coils Determine size of inductor coils Connections between MEMS and inductors

Acknowledgements Justin Williams Josh Medow Willis Tompkins