Development of Urinary Tract Infection Detection Machine (the antibiotic finder)

Supervisor: Dr. Suman Kapur

Duration: May 2013 - July 2013

Project overview:

Point of Care Testing can be defined as medical testing carried out at or near the site of patient care. With the adent of portable technology, simple and relatively less complicated bological tests, like blood pressure tests or pregnancy tests, can now be carried out at home, courtesy of point of care testing devices. Such devices are found to be of great importance in India, especially in rural areas where access to a hospital is difficult ad getting test results can take many days at a stretch. The antibotic finder machine, or as we used to call it " The UTI (Urinary-Tract-Infection) detection machine", is one such point of care device that has revolutionized the world of self-testing in India. The aim of the device is to test anti-biotic senstitivity of bacteria and other pathogens, found in the body fluids of patients. It does not require any big infrastructure and can give results within hours. At the launch of the dvice, it was received with great appreciation and a couple of nwespaper articles were published that mention the achievement. Links to the online articles are provided below.

My Role : Development of the device was quite a long process, and I got involved in it as a "lab-oriented-project" student, during an on-going semester. When I joined the team, there was already a working prototype that was being subject to testing. I had the task of solving some of the issues in measurement, like inconsistencies, that were showing up from time to time, and also to address the usability issues, including the mechanical design .

the prototype the assay I spent my initial days learning from the PHd students in the lab, about the working of the machine, and about the kind of results that are expected to come. After having an overall idea about the electrical, mechanical and the biological functioning of the machine, I started pinpointing a few issues in the electrical designs, and solving them. These were all minor issues like improper voltage control, that could add up to an inconsistent result. The prototpe was using an arduino mega board, other parts like a color sensor, an infrared LED were all connected through a comon PCB to the arduino. After having understood the algorithm the ball and screww arrangementthat was already programmed into the arduino board, I could point out a few redundancies and loopholes, and I tried to fix them. Moreover in my attmepts to bring about improvements I also proposed a new algorithm . The machine has a moving tray of samples (the assay), which is moved by a stepper motor, and it has to stop right below a sensor, to test each sample for the presence of cloudy pathogens. In order to improve the readings, I proposed an algorthm which takes several readings above a single sample, at different positions, and takes the average, giving more weightage to the reading near the center of the sample well.

Later on as we realized that the electrical improvements were highly related to the mechanical arrangement of the machine, quite a few students from the mechanical engineering department were brought in to help. During that time, I also helped them to understand the existing machine, and the goals that we wanted to achieve. Along with the other students, I was involved in the design of the new and improved prototype.

Problems faced : We realised the amount of effort that goes in to move from a prototype design, to an industry grade product. The problems of inconsistent readings would crop up qute often and sometimes minor causes like failing of an electrical part, were quite difficult to find out. Other than that, there were some problems with mechanical inaccuracies of the parts being used. It was proposed to change a rack and pinion arrangement for movement, to a ball and screw arrangement for achievening high precision. Sometimes we also took outside help from manufacturers to solve our mechanical issues.

links