ARDUINO, DIY, Electronics, Inspiring, LEDs, photography, Raspberry Pi, Robotics

Experiments with a Light Meter

Why I am interested in Light meters?

When I was working in Scotland, I came across photo dynamic therapy (PDT), which uses light sensitive drugs to kill cancer cells. In the entire UK, there are only two PDT centers (afaik), one of which is in Dundee. By visiting the PDT center in Dundee, I realised that after applying the PDT drugs, doctors ask patients to wait in  sun light for two hours. There is no particular reason for exactly two hours of exposure to sun light. Therefore, it is not possible to know how much light dose has been received by the patients. To address this problem, PDT center at Dundee measured sunlight across the UK and Ireland and suggested that  cheap lux meters can be used to measure the required lux dose. I met with one of the PI and discussed about this in detail.

The problem with cheap light meters:

However, most commercially available cheap lux meters can only give instantaneous measure of light. These are originally developed for photographers to know lighting in their photo and building mangers to know lighting in a room. But PDT application  requires the lux values to be logged, aggregated to know whether the required light dose is reached. I think the only way to realise that is through connecting the lux meters to a microcontroller and stream the values to a smartphone. For that I am going to use a cheap lux meter that I can confidently modify after reading this blog post .

What I did:

I ordered the lux meter with a brand name “Ceto”from the same vendor as suggested in the blog post mentioned above. I identified the pins required to tap to get the lux values out. These are the pins on the amplifier. I soldered wires to these pins to read the voltage. So effectively LUX values are converted to voltage values in this lux meter. For example LUX of 290 is converted as 0.288V. I connected these wires to a multimeter to  see these voltage values.

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Guts of the LUX meter

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Zooming inside

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Red wire is signal

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Black wire is ground

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Hot glue to keep the wires in place

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Made a hole to the case to let the soldered wires come out, so that I can feed them into a multimeter

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More hot glue to fix the wires to the case

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Connected the wires to multimeter and we can see the light values appearing on the Multimeter as voltage values.

In the next step, I will connect the lux meter to a Arduino Uno and Bluetooth so that its possible to record the  aggregated lux values overtime time to determine the light dose for PDT treatment. I will write these details in another post.

P.S: It is just one of my hobby project, not related to my research.

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DIY, Electronics, Inspiring, Robotics

DIY Toy Centrifuge

Why I like a centrifuge?

Whenever I see a motor, I think why shouldn’t it be converted as a centrifuge. I like centrifuge as a scientific instrument, especially after seeing Lab on DVD systems to diagnose diseases. Recently, I came across Manu Prakash’s paperfuge, where whirligig/buzzer toy was modified to get high speed centrifuge without using any electricity. Although, I like the idea, it still takes more than 15 minutes to separate blood to any useful analysis such as malaria detection.  May be there are better ways to improve the existing technology to get a better centrifuge, a cost effective, functional, may be little bit funny one. Latest open source models use brushless motors used in drones to make a centrifuge. I would like to try that idea. However, one has to spend at least spend $30 to make such open source centrifuge. I would like to make a low-cost, fun toy type centrifuge, so that we can teach kids about centrifuges without spending so much.

How I made One:

I took a brushless DC motor from a CPU cooling fan and attached a conical shape of plastic that I cut from a water bottle. It looks good, I am getting decent speeds with a power bank or a computer USB. Look at the videos, where I tried to separate milk, which is not possible with this toy centrifuge. I am sure that we can separate some suspension solutions which I will try soon. So far the plus points of my design are that it doesn’t require any soldering, 3D-printing. I am planning to enclose it in a cardboard box for safety reasons, although current version doesn’t spin at high speeds to make any damage.

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Top part of a water bottel

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Attach the cap to a PC fan

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Glue to attach the cap

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Finally, PC centrifuge is here

Future Plans

I am trying to make a centrifuge that can go up to 16,000 rpm, with a system similar to the above. I already designed a 3D printed holder for tubes. I will update about it soon. Until then enjoy the footage of toy centrifuge video.

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ARDUINO, Inspiring, Robotics

Can we 3D print Human beings?

Introduction:

Until and unless, you are hiding under caves, you might have heard about 3D printers. If not, 3D printing is just one step more than 2D printing. In normal 2D printing,  information is printed on a surface (usually a piece of paper).  In 3D printing, we can construct three dimensional objects by continuously printing one layer on top of another layer. Using this advanced technology, we can print plastic toys, concrete houses, custom shaped) chocolates (ah Chocolates :p), cars and even rocket engines. Most of the time, we see hobbyists using the 3D printers to make cool plastic models.

What bio scientists can do with 3D-printers?

They can use 3D printers to print the artificial organs using single (live) cells as building blocks. Recent examples of brain cell, heart embryos, prosthetic skull, and legs are evident of the exponential growth in the 3D printing technology.

That immediately, brings up the question, can we put together the 3D-printeded tissues of heart, brain, skull, skeleton, and nerves to make/3D print a complete animal, even a human being?

Does God permit us to do so?

Most of the religious scriptures tell us that we are all constructed from the basic elements soil, water and air. Bible says 3 elements, Baghadgita says 5 elements and Quran says just 2 elements. So the point is somehow it’s possible to copy the Nature, if not the God.

So can we do it?

Let’s do the math first. A human body consists of 10^14 or 100 Trillion single cells. 50 Million cells die/replaced every second.

Little philosophical pause

That means part of us are die and reborn every day. Can you appreciate the beauty of God’s creation for a moment? How complex giants are we?

Let’s come back to science

Using the current 3D printing technology developed by Prof. Boris Chichkov in Germany, we can print 10^8 single cells per second. That means a complete human body can be printed in 2 hours and 47 minutes. Hold your breath. Prof. Boris Chichkov is claiming that it’s even possible to improve the current technology to print 10^10 single cells per second, we can 3D-print a man/woman in 30 seconds. I don’t know about you, but my heart skipped a beat when I was looking at those numbers for the first time. So many philosophical questions were blowing my mind, and I don’t have answers for any of them.

Why do you care?

Because, printing the individual organs, if not the entire body has some immediate benefits:

  • We can print the organs such as hearts and liver to save many lives.
  • For example, In India 200,000 people need a new kidney every year and 100,000 need a new liver. We can stop people dying due to lack of organ donors.
  • In many cases, like developing countries, organ replacement is a costly affair and it involves many kinds of bad things such as human trafficking. So we can avoid that mess, by simply printing the required organs, like how we buy an injection in a shop.
  • The 3D printed bodies can be used as pedagogic tools to teach biology/anatomy to students. Imagine saving lives of many frogs and rats in scientific labs to learn biology.
  • We can rapidly test the drugs on artificial organs, before going for trails on rats and human beings. It will save serious money and time to develop new drugs.

 

Why do I care?

Because, apart from the above reasons, I am making a syringe pump in recent times. Using that I am going to make a bio printer, not to print organs but to print biostructures such as….I don’t know yet. But why? I am just curious. How? Will tell you soon. Is it my main research? Hell no. It’s just one of my hobby project. So it will take some time to see the pictures and videos of me doing bioprinting.

Take away message:

Yes, it is possible to 3D print human beings, or in general animals (at least in principle). Like any technology, it’s more useful than harmful when used in the right spirit.

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Inspiring, Machine learning, Raspberry Pi, Robotics

Raspberry Pi Spotter

 

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What is it?

Rapberry Pi Spotter basically recognizes the features in a given image. It analyses the images taken from a webcam connected to the Raspberry Pi and tells us what is in the image. Please see the video of jetpac in my previous post.

Why it is important?

The importance of this software is that, it does all this image analysis in offline. One might wonder how come the Raspberry Pi with little CPU power can do this. As I have explained in the previous post, Pi does it through its powerful GPU.

I thought it is really cool, if I can implement it on a simple Robotic platform. The robot goes around and keep  informing us what it sees in its surroundings, just like in the video shown by Jetpac.

What did I do ?

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So I have constructed a basic robot with an RC car, and connected a webcam to Pi (The construction details and better pics will be detailed in the next post).  Then  I have Installed the webiopi to get the video stream. Then I have implemented the browser interface as shown  in the above pic for the Raspberry Pi.  Now the Robot can be controlled from any device with a browser. I will upload the  demonstration video soon.

How does it work?

The arrow buttons on the interface control the Robot’s movement. In the above, the video is streamed just like the cambot developed by Eric / trouch. The yellow button above the video stream is to implement the deepbelief software.

When we click on this spotter button, webiopi will search for the latest image captured by the webcam and deepbelief will find the features in that image. Then it displays the results in the text box above the spotter button.

How to install it?

In my previous post, I have explained how to install the deepbelief network on Raspberry Pi. You can find the instructions to install the webiopi here.

I have uploaded my code into github. Note, that the code is really very rough at the moment. This code will work, even if one does not have a Robot. In that case the arrow buttons do nothing. However, video feed will be analyzed as in the original video of jetpac.

First, one has to download the files of cambot.py and index.html into a folder, where the deep belief software was installed previously. We also need to configure the settings of motion, so that it will stream the images directly into that folder. I will write detailed instructions with videos when I get more time.

Comments:

Results are not that great.  One reason might be I am not looking at real life objects. Anyway, I am not concerned about the quality of results yet.  Also, my coding skills are very limited. I hope people with better knowledge of python, in particular webiopi and deepbelief can make it work even better. One concern is that my Pi has only 256 MB of RAM. So it usually keep freezing under load. May be 512 MB RAM Pi will give a smoother experience.

Credits:

I would like to thank Pete Warden (CTO of Jetpac) and Toshi Bass (in Webiopi google group) for helping me throughout this project. I am also thankful to guys at stackoverflow for their help with the python doubts.

 

Continue reading

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Inspiring, Photonic Crystals

Entertaining double slit experiment

“My personality is who I am, but my attitude depends on how you treat me”

Recently you might have heard a lot about light, wave, matter, particle and more scary stuff like quantum mechanics, thanks to Nobel Prize for Boson guys. You might thought it’s too crazy stuff, only few people can understand. But we can see this crazy stuff in front of our eyes very easily. I will share with you today one of the most important things in quantum mechanics, that is wave nature of light. Light is a wave as well a particle at the same time. But depending on our experiment we find it as either a particle or a wave, but not both states at a time like the above quote. I want to share with you a double slit experiment in which we find light behaving as a wave. Often times you see only a boring graph or simulated video of double slit experiment, but how in real life we can see the double slit experiment.  I do not want to waste your time, so watch this entertaining video. If you don’t have time, just watch it for less than a minute part between 4.20 – 5.00 minutes in you tube.

(This guy is crazy he has amazing videos on science, they really blow your mind)

Why did this I posted, because something interesting will follow this. That later post will explain the beauty of butterflies.

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Inspiring

Nobel prize in Physics 2013

Today the Nobel prize for Physics 2013 was awarded jointly to François Englert and Peter W. Higgs. You might remember Higgs…yeah that Higgs Boson or God* particle guy. So the prize is awarded for their theoretical discovery  that explains how mass is originated. They proposed for the first time in 1964 that a Boson (later called as Higgs Boson) was responsible for the mass of the particles inside the atom. Those sub-atomic particles indeed give the mass to atoms, and after that you know how to build the story. Atoms give mass to everything we know, you, me and all the objects around us. Therefore it was very important in the first place to understand how the mass enters in and around us. This is a very fundamental question, since Englert and Higgs answered it for us; they were awarded the greatest prize of Physics. Don’t forget though the contribution of CERN’s Large Hadron Collider (LHC) that generated all the interest of common people around this God* particle by confirming the existence of Higgs Boson on 14th March 2013.

I listed below some interesting facts about Higgs Boson

1) Higgs boson is the missing piece in the puzzle of standard model to prove that standard model indeed correct.

2) Why standard model is important? Although there are many other theories to explain the origin of world around us, standard model is widely accepted theory but it is also incomplete and, in fact, internally inconsistent.

3) According to standard model theory, the Higgs particle is a Boson with no spin no electric and colour charge. It is very unstable and it decays in to other sub-atomic particles immediately.

4) LHC not yet confirmed all the properties of Higgs Boson that were predicted by standard model, but it confirmed the most important properties such as + parity and zero spin.

5) What’s the impact of this discovery?

Good question, world will not change just now..so relax. We cannot predict the impact of fundamental discoveries immediately. When quantum mechanics was proposed even their discoverers described it as an “interesting laboratory experiment” with “no useful purpose” whatsoever. But now we have its applications in computers, mobiles, satnav and many others.

6) At least any immediate side benefits?

You know World Wide Web was created by physicists working in global collaborations on particle experiments at CERN to share their results, and the results of massive amounts of data produced by the LHC

Similarly cloud computing was created by them as it was difficult to analyse 300 trillions of proton–proton collisions that amount to 25 petabytes (1000 petabytes)  of data per year as at 2012.  Now we all use www and some cloud computing service.

So keep your fingers crossed and wait for new discoveries out of Higgs Boson. First congratulate our Nobel Prize winners Englert and Higgs and remember remaining four physicists who contributed to the theory and many others who worked on alternative models. Every small contribution counts in science.

*Finally don’t call Higgs Boson as God particle. It is nothing to do with God. It is a name given by media.

Image

The six authors of the 1964 PRL papers, who received the 2010 J. J. Sakurai Prize for their work. From left to right: Kibble, Guralnik, Hagen, Englert, Brout. Right: Higgs.

(Most parts of the information for this post is collected from Wikipedia)

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