The Review Effect: Papers & Models!!

09:50 am

Yes, back after a big gap! Not healthy. Was busy with reviews, which I consider are a waste of time. Lost out on 4 days worth of project work or Image processing studies. Upset, but can't help, gotta move on.

Alright, so the last time, my external guide, and me, had a discussion, we decided on having a computer simulated model for utero-placental, or umbilical artery, or middle cerebral artery. He suggested something new, quite exciting. Instead of modeling the blood flow physically, we could model it electrically. He even sent me a model that he found on www.biomedical-engineering-online.com. Nice website,.. so much of information available. Wish I had more time to go through this.

A thing that excited me the most of the use of an electrical model. This excited me not at the time that he explained the model to me, but after the reviews took place. Because in the reviews I realised what the ethical committee considers important and authentic for the publication of a paper. Advantage of using an electrical model is that on one hand we could implement its hardware and obtain the output, on the other hand we could simulate the model on simulink and obtain the output. Match both the outputs and check if they are anywhere close to the actual physiological output. If all these match we will end up with a good authentic model.

Now, we have realized that we need to create a utero-placental circulation model whose output needs to be a velocity profile of blood flow vr, as given out by the doppler signal of the ultrasound machine's doppler mode, so that I can then use it according to the following relation,

fD = (2 f vr cosq )/c

to generate fD which can be used in matlab to generate an audio output. This will then, be varied under various circumstances, to obtain a database to train my Artificial Intelligence module.

Need to search for papers that describe various utero-placental models predicting the doppler waveforms.

A paper " Effect of non-linearity in predicting doppler waveforms through a novel model " is the best that I've found till now. 

Other than that, a paper referred as, A transmission line modelling approach to the interpretation of uterine Doppler waveforms. also seems nice, which is the base paper for the previous one. So, basically the same concept. 

Then there's this paper Gestational age dependency of umbilical flow waveforms: an investigation using a lumped parameter model whose content again, I cant see. 

Then there's Markov Based Mathematical Model of Blood FlowPattern in Fetal Circulatory System. I'll have to search for at least 2-3 more before going to studying the models that are available to view.

ATB!

Promising Optimistic Discussion, Heavy Dreams!

12:15pm

Had a very calm cool, and constructive discussion with my exter nal guide yesterday. Felt good that he did appreciate the model that I had suggested. Guessing he just read it. Hmm.. But we talked and found out a good way to solve this problem. Have formed the minutes of the meeting as always, to really understand in short, what he wants me to do. Here they are: 

Discussion About Various Ways To Simulate The Blood Flow

The ‘Timing the delivery of preterm fetus_A case study based on computer simulations’ paper gave a good model. It's sort of a neural network where you build the model using patient data. Then you know what is the input and you know what is the output. Then you build a neural network and give a test sample, as an input and then your output would be something that the model would throw up as the solution. But the problem is the validation of the interpretation of the acquired patient data, since it is always subjective.

Using Simulink model is a good idea. Simulink is basically blocks available on various functions on the on the in the MATLAB program. But,we need to enter a model into Simulink. Also we need to be sure that the model is a good model, in order to build it. One solution can be that, we could contact, the people who wrote ‘Timing the delivery of preterm fetus : A case study based on computer simulations ’ and see if they are ready to give that patient data or that model itself.

There are, also, electrical models of blood flow. You can build an electrical model for blood flow, and model the flow as electric current. Depending on the diameter of the vessel you can arrive at the resistance of the vessel, the capacitance is basically the elasticity of the vessel, that tells how much the vessel is going to be pulsatile.

Rough Project Plan

If we do a some kind of a literature survey, we should arrive at at least 3 or 4 models, and we can chose one of them with a good reason, like e.g., the way the validation is done. In our first chapter then, we may have to list down various models that we have analyzed and why we chose the model. It would be nice to use a model already validated by someone and simulate it using Simulink.

Then you try out changes in some of the parameters, and see how the flow behaves. On this, we can apply some kind of an algorithm and demonstrate that the signal processing technique can identify such flows. e.g., we could simulate a flow whose resistance changes with time, the changing the flow behavior. We can pick it up, using the signal processing algorithm. This could then show that it can be a very useful technique which can be used in actual ultrasound machines. And using those simulations and results we can approach any hospital.

Thus, we can have a firm grounding to show the ethical committee the experiments that we have done on our computer simulations. They and the patients too can check it up, and decide if they could share their data. This makes a logical sense.

Short Timeline

14^th October 2012: Identify all the models we can and talk about the different models we have.

21^st October 2012: Fix on a particular model based on how they have validated it etc. with a logical reason.

At the same time, we can study and start building the various scenarios that we want to simulate using Simulink, because then we can start planning on which algorithm you will chose in a particular scenario.

So now, my trouble is that, I have so many things at hand.

1) Search for at least a model per day

2) Prepare for Project Review

3) Image Processing Study, coz he is really demanding.

Today's plan is, Image processing till evening, and Project Review at night.

ATB!