Hello there, in the past week, we divided ourselves into groups so that we cover a lot of stuff. We managed to do many activities compared to the past weeks. (Groups are the best!)

The first group was working on the suction pump control system circuit designs. The designs that we came up with were:

• On top Infrared sensor

The infrared transmitter and the receiver will be positioned on top of the suction bottle (tank), and the infrared (ir) signal will refract on the surface of the liquid and will be sensed by the receiver. The level of the liquid in the bottle will be measured by the time the infrared signal will take to reach the receiver.

• Side infrared sensor

The transmitter and the receiver will be positioned and aligned on opposite sides of the bottle. When the bottle is empty or the liquid has not reached the level where the sensors are, the ir signal will be sensed by the receiver, however when the ir signal is blocked or it is bent, i.e. the ir signal does not reach the receiver, the control system will shut down the motor.

The other group was working on the mechanical designs of the control system. The designs that were proposed were:

• Stand design

A mechanical stand to hold the sensors in position

• Belt design

A belt that will hold the sensors and that will be wrapped around the suction pump bottle.

Another group went to Queen Elizabeth central hospital to talk to the nurses about our designs of the suction pump control system. The nurse preferred the belt design because it takes less space than the stand design and it is easy to use.

The past two weeks have been all about designing and developing a low cost digital phototherapy dosing meter. A Phototherapy dosing meter is used to measure the intensity of blue light that is administered to babies that are suffering from jaundice.

At Queen Elizabeth central hospital, the biggest government hospital in Blantyre, there is a shortage of phototherapy dosing meters. The meter they are currently using was designed by Greg Nusz and Advait Kotecha in cooperation with engineering world health. Since this meter uses an analogue meter to show the reading, it suffers from calibration drift problem. This renders the meter unreliable.

Objectives:

 Our main objective was to design and develop a low cost digital   phototherapy dosing meter which is portable, accurate and has no calibration drift problem.

 We had two prototypes that were already developed, one from rice,  another from fifth year students from poly. We chose the prototype from Poly which uses an LCD to show the readings instead of an  analogue meter.

Design:

We made some modifications to the Poly prototype:

1. Changed the sensor.
2. Modified the circuit.
3. Changed the meter casing.

Progress:

Right now we are almost done with the dosing meter, the only thing which is remaining is, calibration. We are waiting for a commercial dosing meter to use as a standard meter.

I was so thrilled (and a little nervous), when I heard that I had been selected to be among the few students that would be doing the Rice and Poly internship this summer. The chance of working on different biomedical projects together with fellow students from Rice University, was indeed an honor.

The first week was fun, meeting our cool friends from Rice; Emily, Sarah and Catherine; teaching them a few Chichewa phrases and Shopping for the materials that we would use.