MRI INFUSION PUMP Group Members: Aman Ghotra – Team Leader Can Pi – Communicator Miguel Benson - BSAC Prakash Rao – BWIG Client: Dr. George Newman, Ph.D. Frank Hospod Advisor: John Webster, Ph.D.

OUTLINE Problem Statement Client’s Requirements Designs 1-3 Spur Gear Vane Pump Peristaltic Pump Decision Matrix Stepping Motor Design Proposal Future Goals

PROBLEM STATEMENT Current MRI compatible infusion pumps are syringe-driven Limitations: Flexibility in programming Saline and gadolinium capacities (60 mL and 60 mL, respectively) Time Consuming (~7 min) www.medrad.com

CLIENT REQUIREMENTS The pumps must: Be made of a non-ferrous material Minimize gadolinium or saline waste Deliver accurate flow rates (0.2-4 mL/s, ± 0.02 mL/s) Be easily sterilized and durable Be programmable Sequence: saline→bolus →saline →infusion →saline Manage time to produce consistent images Attach to containers (60/180 mL)

SPUR GEAR PUMP A pair of matched gears rotate in opposite directions. The air pockets created by the rotating gears draw in the liquids. The fluid exit at the outlet of the gear. http://www.mech.uwa.edu.au/DANotes/gears/meshing/meshing.html#top

PROS & CONS PROS Low cost Simple Reliable Efficient CONS Hard to sterilize Sanitizing solution Replacement

VANE PUMP http://www.animatedsoftware.com

VANE PUMP (cont.) Cost Varies greatly $174 - $2993 Parts Rotor Vane plates Casing http://www.animatedsoftware.com/

PROS AND CONS Cons Pros Complex Develops good vacuum Not for thick liquids Contamination possible Hard to Clean Pros Develops good vacuum Good with thin liquids Can change displacement and angle

PERISTALTIC PUMPS Flow rate controlled by roller clamp Tube walls squeezed to form seal as roller moves along tube More rollers increase accuracy http://www.animatedsoftware.com/pumpglos/peristal.htm

PERISTALTIC PUMPS (cont.) Positive Displacement Pump Used in a variety of medical applications http://www.pump-manufacturers.com/suppliers/environmentalpumping.html

PERISTALTIC PUMPS (cont.) Accuracy decreases as tubing wears and loses flexibility BUT, tubing will be changed after every patient Very sterile – no external contact with fluid Typical price range: $170+ http://www.uspto.gov/

DESIGN EVALUATION Maintenance Efficiency Cost Accessibility Total Spur Gear Pump 1 2 3 8 Vane Pump 6 Peristaltic Pump 11 0 – worst; 3 - best

STEPPING MOTORS Converts electrical energy into motion Characteristics: Voltage = Torque Low cost ($60 & up) Easily programmable C/C++ Program Labview http://eio.com/step-rot.html

DESIGN PROPOSAL Alternative: If we can’t find out how to deshield the pump/motor case: We will have the motor in the control room and connect this with the rest of the apparatus through the wall.

FUTURE GOALS Work on budget with client Buy parts to assemble pump Buy an economical Stepper Motor Learn programming Figure out deshielding options/nonferrous materials

Questions?