Progress Report, Week 7: October 25th
These last two weeks we have redefined our customer needs and technical requirements based on the feedback from our first presentation. We have refined our alternatives plans and determined specific obstacles with each. We have started brainstorming ways to overcome these obstacles and are almost to the point where they are ready for comparison using the QFD chart.
Our three alternative plans can be referred to informally as Elastic Indicator, Water Reservoir, and Optical Indicator. Some issues we encountered with these designs, respectively, include placement of the elastic ring relative to the arm and what material to use, movement of the patient and accuracy (possible time delay between pulse and visible water disturbance), and lastly a non-electronic light source.
This week we plan on outlined schematics for each design as detailed as possible, as well as preparing for the presentation by determining proofs of concepts and parameters for each.
Also this week we created a proposal to indirectly incorporate the Arduino microcontroller:
Problem: To design and use a controlled system to test the accuracy of any prototype device.
Proposed Project: We propose to use an arduino microprocessor to implement a designed program that will control a fluid (water, air, synthetic?) system that will adapt to user input values (pressure? frequency?).
- Plan of Activities:
- Gather relevant properties of the system (brachial artery diameter, density/elasticity of “flesh”, fluid viscosity) that will serve to physically represent the arm and mimic dynamic changes in response to the cuff; also hardware (microcontroller, two force/pressure sensors, syringe pump)
- Gather materials that best mimic these properties (ballistics gel?)
- Write a program that will control the speed of the syringe pump as well as record the real pressure inside tubing and the forces that reach the surface of the [ballistics gel]
- Test each prototype by setting a program for the arduino microcontroller to a systolic and diastolic pressure and comparing it to results from measurement taken with device