Leg Compression Device to Assist in Ultrasound Testing

Design Team: Mark Rawls and Jordan Winston

Advisors: Dr. Raul Guzman and Dr. Paul King

Problem Formulation

When performing the medical test to detect deep vein thrombosis (DVT) the technician often has difficulty squeezing the leg and operating the ultrasound machine at the same time The main problem with the current method of testing for DVT is that it involves manually squeezing the leg to induce blood flow through the veins. This is a problem because the technician has other tasks that require the use of his/her hands such as operating the ultrasound machine and holding the ultrasound transducer.

Potential Solution Directions

Innovations Workbench was used to develop potential solutions:

Affixation of Transducer to Leg

Relocation of Ultrasound controls

Device to Compress Leg

Cost Effective Solution

Courtesy: http://www.hku.hk/surgery/vdc/vdc_diagnostics.htm#Duplex

•Fixing a transducer to the leg is not feasible due to the amount of shifting and compensating that is required during the test

•Relocating the ultrasound controls to the transducer is not feasible due to the immense cost involved in re-designing the common ultrasound machine

•Designing a device to compress the leg is the most feasible option in both cost and practicality

Wants/Needs

Needs: Adjustable Size, Attachment at Variable Locations, Foot Control, Safety Mechanisms, Rapid Squeeze/Release Wants: Easy attachment, Easy Disattachment, Variable Pressure, Inexpensive Assembly

Initial Design Solution

Initial Design: Velcro/Fluid Compression Leg Cuff

Design Suggestions

Positives Design Achieves

Intended Purpose System Addresses

all Design Needs System would be

cost effective to build

Negatives Design Achieves few

of Design Wants Particularly, the

system is not easy to attach and disattach.

Dr. Guzman fears that the product will not be popular unless it is simple to use.

Revised Design Solution (in progress)

• This revised design improves the speed and ease of applying and performing the leg compression while still satisfying the needs of the device, thus making it a better and more user-friendly solution to the problem

Market Potential

600,000 patients per year are hospitalized for DVT in North America Approximately 6000 registered hospitals in the U.S.Initial market for the device will be about 3,000 unitsEach unit could be sold for around $333, corresponding to $1,000,000 in initial incomeSubtracting $500,000 for patent protection, regulatory approval, manufacturing costs, and marketing leaves an initial profit of $500,000In the future, with approximately 10% replacement annually, and costs decreasing to 25% of income, the device could generate an additional $75,000 per annum in profit

Design Timeline

December 12, 2001 – Observe several procedures and have a rough design for the device on paper.January 18, 2001 – Finalize designs for the device including extensive analysis of potential safety risks and usability issues. Begin gathering the materials and components to construct a prototype.February 15, 2002 – Begin building the device, testing the various components and the overall operation of the device as it is assembled. Make any adjustments or modifications to the device to account for unforeseen difficulties or to improve performance.March 30, 2002 – Complete an initial prototype for the device and begin testing.April 15, 2002 – Redesign the device to account for any problems or improvements discovered during the testing phase.May 15, 2002 – Complete a second prototype for the device and begin testing for accuracy and usability.May 30, 2002 – All modifications have been made for the device and a final product is unveiled.