-
-
Skip navigation
(Access key: S).
Contact information.
The goal of this project is to develop a device that accurately and automatically timestamps an x-ray radiograph upon exposure. This is important for radiologists because often they have to make proper diagnoses for conditions that change rapidly. If the radiologists knew the time at which a series of x-ray images
were taken, rather than the time the images were processed and developed, a better understanding of a patient’s condition can be established. The device will ultimately be attached to the computed radiography (CR) cassette (see below) and will consist of three distinct components: an x-ray sensitive circuit to detect and amplify an x-ray signal, software to clock the exposure time, and the necessary hardware to interface the two.
The CR Cassette
Final Design
The first phase of our design is a transresistance photodiode amplifier that behaves as a current-to-voltage converter. Due to the op amp we chose, our amplifier has very high input impedance, a very low input current, and an exceptional speed performance. As shown below, the gain will be the feedback resistance. A 10k resistor was chosen for the photodiode sensitivity since we tested our amplifier with light. With x-rays, the sensitivity
must be decreased.
To interface the circuit with the laptop and PDA, we used a NI SCB-68 Shielded Connector Block, a NI SHC68-68-EP Shielded Connector Cable, and a NI DAQ card. Below is the layout of our final design.
The circuit is completed and runs properly. Two LabVIEW modules have been developed with the hope of integrating them into one module.
| Week | Reporting Period Beginning | Activities |
|---|---|---|
| 1 | September 3 | Talked about initial project and found out it was cancelled |
| 2 | September 10 | Chose the x-ray time stamp project and researched computed radiography |
| 3 | September 17 | Met with client and toured the x-ray facilities at UW-Health, continued to research problem |
| 4 | September 24 | Worked in small groups to come up with possible solutions to the time stamp dilemma |
| 5 | October 1 | Started working on the presentations. Each pair finalized their final 3 design ideas and chose their best one to present on 10/8/04. |
| 6 | October 8 | Gave mid-semester presentations. Started planning for the paper as well as we met with the client and came up with a possible prototype. |
| 7 | October 15 | Completed mid-semester paper. Met with Wally Peppler to discuss final design. Started planning for upcoming purchases. |
| 8 | October 22 | Met with Professor Webster and discussed other circuit designs. Divided up work for circuit design and LabView Programming among the 6 members. |
| 9 | October 29 | Designed the LabVIEW program to record the time. The circuit has been started. |
| 10 | November 5 | Developing the Bluetooth client and server software in LabVIEW. The circuit went under construction. |
| 11 | November 12 | Ordered the parts for the design. The circuit is under development but it works and the LabVIEW program is ready for testing |
| 12 | November 19 | Continued to work on the circuit and the program. Some of the things we ordered started to come in. |
| 13 | November 26 | Thanksgiving break. We ordered the PDA and connector block. We also started the poster presentation. |
| 14 | December 3 | Tested prototype. The LabVIEW program seems to work with the photo-sensitive circuit! Gave final poster presentation. |
| 15 | December 10 | Finished final paper. Met with Prof. Webster to discuss final prototype, report, and future work. |
 |
Mid-Semester Report (Oct 15 2004, 572 kb) |
 |
Mid-Semester Presentation (Nov 30 2004, 1832 kb) |
|
Final Poster Presentation (Dec 4 2004, 6344 kb) |
|
Final Poster Presentation (Dec 4 2004, 580 kb) |
|
Project Design Specification (PDS) (Dec 8 2004, 22 kb) |
|
Final Report (w/PDS) (Jan 9 2005, 891 kb) |
