Overview of the Original Diagnosis System
BME 100 class of 17 teams with 6 students on each team was able to diagnosis 34 patients for the disease-associated SNP. The testing was done over a period of about 2 hours for each team. Many things were done to prevent error within the testing. Each team was given 2 patients and each came with 3 replicates of their samples. Also, each of the 3 replicated samples had 3 drop images taken. Through having multiple test on the same subject the teams were able to decrease the chance for error. The teams also calibrated the equipment before hand with known concentrations in order to properly test if the equipment was working. These calibration samples had 3 drop images taken of them. This allowed the imageJ to also be calibrated to test if the software was working correctly. All of these things were done by the teams to prevent error within the testing. The class’s final data resulted in 3 positive conclusions, 10 negative conclusions, and 1 inconclusive conclusion. Thirteen out of the fourteen conclusions were successful, with no blank data.
What Bayes Statistics Imply about This Diagnostic Approach
For calculation 1 the patient has a moderate chance of having the disease SNP given a positive PCR result with a chance of about 50%. For calculation 2 the patient has a high chance of not having the disease SNP given a negative PCR result with about a 100% chance. Our results had a moderate level of sensitivity and a high level of specificity.
For calculation 3 there is a moderate reliability in predicting the development of the disease SNP given a positive final test conclusion with a chance of about 70%. For calculation 4 there is a high reliability in predicting the development of the disease SNP given a negative final test conclusion with a about a 100% chance. Again, our specificity was more reliable than our sensitivity.
Possible Error
One possible source of error could be due to the limitations of the micropipette to draw up and effectively transfer all 100 microliters of the PCR sample to the buffer tube. This change in volume could have negatively affected the PCR concentrations and the Bayes values. The sensitivity of the camera used to take images of the droplets could have affected the accuracy of the measurements of the droplet. If the images were not clear, the Image J program would not accurately measure the droplet, negatively affecting the data. Also, the accuracy of the Image J program could have skewed our data, as when the circle was placed around the image of the droplet, the program could have measured some empty space around the droplet.
Intro to Computer-Aided Design
3D Modeling
SolidWorks was used for this assignment due to the familiarity we have with the software. It is an advanced 3D modeling software that allows more in depth customization and design for our product. Using SolidWorks to design the adjustable stand was difficult to get the detail we desired in our stand design. The hardest part was to design the curved surface of the legs, and to match the dimensions from one pieces to the next. However, through the process new techniques such as the thread function were utilized to design the final product as accurately as possible. The piece was split into two parts between two team members. One member built the box with the on/off switch, and the other member built the legs that were added to the original design. Then, through research and teamwork, we were able to find solutions to our design problems within SolidWorks.
Our Design
Our design implements an adjustable stand that is attached to the traditional fluorimeter system that enables users to easily adjust the height of the fluorometer to take more accurate photos of the PCR reaction. We chose this design because we had trouble taking pictures of the PCR reaction from the right angle and height, and had to continuously add plastic trays to the bottom of the fluorimeter in attempt to align it with the camera on the phone. The stand will eliminate the need for extra supplies, (such as plastic trays), to raise the box and will make the process of finding the correct height for the most accurate picture more effective.
Feature 1: Consumables
The addition of a stand to the fluorimeter does not affect the effectiveness of any of the consumables that are used with a traditional fluorimeter. Therefore, our design does not require any new consumables to be packaged with our product. Very important consumables include the consumables that are required to run the fluorimeter and are difficult to acquire otherwise. Because our stand does not require the addition of newly designed consumables, our kit, including the new fluorimeter with the stand, will be accompanied by the consumables that are included with traditional fluorimeters.
Feature 2: Hardware - PCR Machine & Fluorimeter
Our system is only applicable to the fluorimeter and not the OpenPCR machine. This is because the adjustable stand is required for a fluorimeter, but there is not a comparable component in an OpenPCR machine. Our design allows the user of a fluorimeter to easily adjust the height of the stand that the slide sits on. The traditional Open PCR machine will be used in conjunction with our new design of the fluorimeter with the adjustable stand.
The Stand-Up Guys fluorimeter design addresses a major weakness of the fluorimeter because with the existing product, it is difficult to find the correct height of the stand that is compatible with the height of the phone camera. Our design makes it easy to adjust the height of the stand so it can efficiently match the height of the camera.
Our design increases the ease of use of the fluorimeter exponentially. The ability to use your own phone as a camera for the fluorimeter lowers the cost of the machine significantly, but creates problems when using the device, since all phones are different sizes. The device will be able to maintain its low price point while also eliminating the struggle of setting up the fluorimeter properly for different phone sizes by using our cheap and easy to use design, which will adjust to accommodate different phone sizes. The ability of the device to adjust to different phone sizes will allow for a quicker set-up of the device (eliminating the annoying process of trying to balance the device on other objects in order to achieve the correct height). In addition to increasing the ease of initial set-up, our product will also allow for easy switches between phones if desired.
BME 100 Spring 2017
