MRI Infusion Pump

MRI Infusion Pump

Team Members:

Nate Gaeckle

Tim Eng

9-18-03

Function: The current MRI infusion pump is inefficient, time consuming, and doesn’t perform to the standard that the client wishes. Currently a technician must manually change the gadolinium and saline reservoirs before each bolus infusion. After the bolus, the technician must use a different concentration of each liquid for a second infusion. On average, this changeover takes about seven minutes. In this time, the circulatory pattern of the patient could change due to movements of the patient. This has a negative effect on the results of the MRI. Also, the gadolinium and saline come in pre-packaged amounts. Some patients do not need the whole bottle of solution, and it is tossed out after the infusion. In this way, the current set-up is inefficient.

Client Requirements:

• The pump must be made of a non-ferrous material
• The pump should be design so that no gadolinium or saline is wasted
• It must be able to accurately control the flow rates of gadolinium and saline throughout the scan by the use of computer sequencing.
• Flow rate needs to have a range from 0.1 mL/s to 4-5 mL/s
• Needs to be a way to sterilize each accessory of the pump
• Must be able to perform the contrast infusion right after the bolus.
• The pump must be able to infuse saline alone, gadolinium alone or a combination of the two.

Physical and Operational Characteristics:

a. Performance Requirements: The device will be used on a daily basis, changing syringes for each patient for sterility. The components of the pump in contact with the saline or Gadolinium must be able to be sterilized. It must be able to survive differing amounts of standby and usage times as well as be durable to perform equally well for all patients throughout the day. On average, the hospital sees 2-3 patients a day, but it can get up to about 7 patients a day. The average usage time of the pump is around several seconds for the bolus injection of contrast followed by infusion lasting 1-2 minutes. The pump must be readily available for use at all times. Air bubbles cannot be present in the pump as they will cause artifacts on the image. The amount of time allotted between patients is approximately 10 minutes for set up. Although it is not high priority, it may be possible to reduce the set up time.

b. Safety: The device must be MRI compatible, so as to not pose any complications with the scan or endanger the patient’s life. The device must be able to operate in a magnetic field of 0.5 to 2.0T. Therefore it must not contain any ferro-magnetic metal. Additionally, the tubing connecting the pump to the patient’s IV must be long and pliable to allow for comfort and ease of movement of the patient in and out of the MRI scan area (~5-6 feet). Coiled tubing is now being used and is satisfactory for the client’s needs. Tubing that is not sufficient in length can cause danger and discomfort to the patient as well as affecting scan quality with slight instability of the patient. The syringes cannot be put under such pressure that they or the tubing will burst.

a.c. Accuracy and Reliability: The pump must be reliable and accurate to deliver fluid in 1 (or 0.5) mL increments. No leakage or coagulation is allowed, as the infusion must be controlled in a constant fashion by the operator. The bolus must be injected in the range of 10-25 mL with +/- 0.5 mL accuracy at a flow rate of 3 mL/sec +/- 0.2 mL/sec. Gadolinium and saline are then optimally infused simultaneously at diluted contrast with a flow rate of 0.25 to 0.35 mL/sec for Gadolinium and 0.65 to 0.75 mL/sec for saline +/- 0.02 mL/sec or better.

d. Life in service: The pump must comply with hospital regulations as to how long it can be used. The device must stay consistent and able to endure daily usage for years with out alteration of hampered performance.

e. Operating Environment: The pump must not be affected by the strong magnetic field in the MRI room. The technicians will have training to ensure proper usage. The pump should be designed so that it does not need a lot of handling, therefore it will not endure much stress or strain in the hospital environment.

f. Ergonomics: The pump will need to be mobile so that it can be set in different areas of the scan room with ease. The tubing, and chemicals need to be able to be exchanged without hassle.

g. Size: The pump and apparatus must be small enough so that it can easily be moved around. There are no restrictions on the size.

h. Materials: The design can contain any material, as long as it is not magnetic.

Product Characteristics:

a. Quantity: Only one design needs to be made in order for our testing purposes, but if successful, this sort of design could be used in every hospital that uses MRI.

b. Target Cost: The desired cost is still undefined, but should cost less than any of the current technology.

Miscellaneous:

a. Standards and Specifications: Since the product will be used in a hospital environment, it must be deemed safe by the FDA.

b. Competition: There are a few different designs of infusion pumps made by companies such as Medrad. There was a design known as the Tomojet® made similar to the clients wishes, but it was bought and suppressed because it was not as profitable for the medical companies.