This video explains the difference between the three modalities of OCT : time-domain, Spectrum-domain and Swept source OCT. A simple explanation of FFT is included
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@maryamsolouti810410 ай бұрын
I saw several videos for OCT and this was the best one that I finally understood the concept vividly. Thank You :)
@AH-oo1oq2 жыл бұрын
Very informative, very nice way of explaining. One thing to also note here is that the intensity of the light is also affected by the absorption of the tissue, which means that sometimes the constructive interference does not lead to the maximum amplitude even though the object is focused. In other words, noise can be generated by light traveres different types of tissues with different absorption factors. This effect makes the images sometimes blurry and noisy. Allow me to add something here, Fast-fourier Transformation OCT is only achieved using specialized line-cameras.
@aatt32093 жыл бұрын
One of the very best tutorials out there on OCT (concept + setup), very glad I saw this video, thank you so much!
@adelabdelshafik3 жыл бұрын
Welcome. Glad to hear your opinion.
@melmel18203 жыл бұрын
You saved my life and you helped me understand something I couldn't understood a really long time ago
@135prashant2 жыл бұрын
You are a genius sir to explain the complicated principle with such patience and ease. I love your presentation
@adelabdelshafik2 жыл бұрын
Thanks. Glad to hear your opinion.
@lachezarkolev30592 жыл бұрын
This is some world class explanation. You broke the topic into relevant parts and explained everything so clearly and fluently. Amazing job. Thanks.
@adelabdelshafik2 жыл бұрын
Thanks. Glad to hear your opinion.
@melmel18203 жыл бұрын
Thank you very much, you are the best teacher ever on KZbin THE BEST
@adelabdelshafik3 жыл бұрын
Glad to hear your opinion
@PreangkaRoy Жыл бұрын
Really, after seeing this lecture, I thought that I have learned more...waiting for the new lecture
@adelabdelshafik Жыл бұрын
Glad to hear your opinion. Thanks.
@Muhammadusman-zi9uz2 жыл бұрын
Very good presentation Sir. Easy to understand and nicely explained. Thank you
@adelabdelshafik2 жыл бұрын
Glad to hear your opinion.
@stelthirdeyeproductions58192 жыл бұрын
This was just what I was looking for, linking the theory with the practice. Thank you Sir! I wonder what is the reason that the swept single frequency light ray method (narrow-band) can get to and hence measure the deeper layers, when compared to the broad band light source method? Is it a matter of increased light power density assuming distances are kept the same? Looking forward to watch your other two videos. Thank you.
@marialiseth7633 Жыл бұрын
incredible explanation! congratulations! thanks for sharing
@lambda49316 ай бұрын
The beam splitters in you diagrams are facing the wrong way.
@jovanantic1362 ай бұрын
Very Helpful
@adelabdelshafik2 ай бұрын
Thanks
@convex93453 жыл бұрын
Hello Sir, I have a doubt. As you mentioned, in TDOCT the light source is monochromatic, but in the literature, it is mentioned that the light source is broadband with continuous waveform. If we use a monochromatic light source then the interference pattern still observes at the unequal path length difference. Thanks in advance
@fadyabsy3 жыл бұрын
تسلم يا بروف شرح اكثر من رائع
@adelabdelshafik3 жыл бұрын
thanks
@Tenjayy Жыл бұрын
Perfect
@abdulrahmanalotaibi1370 Жыл бұрын
Thank you for a very good explanation!!!!!
@adelabdelshafik Жыл бұрын
Glade to hear your opinion
@soheilaakbari181 Жыл бұрын
Thanks,perfect
@adelabdelshafik Жыл бұрын
Welcome
@majidakhzari50715 ай бұрын
The Source of light in SS and SD is same ? SLD?
@sachinmdesai3 жыл бұрын
Thanks sir. Waiting eagerly for more in this series
@adelabdelshafik3 жыл бұрын
welcome. I am preparing an new one these says.
@bspkhaleghi3 жыл бұрын
Very informative Thanks
@adelabdelshafik3 жыл бұрын
Glad to hear your opinion
@dawnlh2 жыл бұрын
Thanks for the wonderful tutorial, it's vary helpful! I wander is it convenient for you share the lecture slides or notes, hope to make a note for future reference!
@adelabdelshafik2 жыл бұрын
OK. I will work on it. Thanks for your suggestion.
@danielaperezguerrero26973 жыл бұрын
Nice explanation!
@adelabdelshafik3 жыл бұрын
Glad to hear your opinion
@AH-oo1oq2 жыл бұрын
One thing is left open here, how to map between FFT Domain to the spacial domain.
@adelabdelshafik2 жыл бұрын
I did not understand the question. FFT domain OCT is another name for spectral domain OCT.
@AH-oo1oq2 жыл бұрын
@@adelabdelshafik For spectal OCT, an inverse FFT is necessary to transform light spectrum (from the line camera) into time/spacial domain relevant to the pachymetry of eye.
@adelabdelshafik2 жыл бұрын
@@AH-oo1oq I believe an engineer is needed to discuss such statement, which is beyond my ability as an ophthalmologist. If you find it useful for ophthalmologists following this channel, you may further explain that point.
@manmathkumardas58563 жыл бұрын
very good video sir, learned a lot
@adelabdelshafik3 жыл бұрын
Glad to hear you opinion.
@srisridurga3 жыл бұрын
Well explained sir.. Thank u so much
@adelabdelshafik3 жыл бұрын
Welcome
@bumkyukim9950 Жыл бұрын
Both TD and SD(SS) use micro purse light source?
@adelabdelshafik Жыл бұрын
Yes. You are right.
@user-nx1rg9tn7z3 жыл бұрын
Hi thanks for the video, some basic ideas are still unclear to me: is the mirror movable in time domain OCT so we do not get destructive interference? How do we know when to move the mirror? Is this a closed loop system where the detector tells the mirror to move back when destructive interference is detected? thanks!
@adelabdelshafik3 жыл бұрын
Hi. To start with I am not an engineer, , I guess the mirror is moving all the time for a fixed distance , as rays are reflected from different layers of retina simultaneously the detector will capture subsequent layers with constructive interface, this will result in detecting 5-6 layers of the retina with certain distance in between with no layer detected hence we can get a section in the retina. Finally have a look at this video : kzbin.info/www/bejne/oF7YZHx7nMiHn7M
@kimbich72353 жыл бұрын
Thanks u😊.
@adelabdelshafik3 жыл бұрын
Welocme
@kimbich72353 жыл бұрын
@@adelabdelshafik Hi, sir, Can you talk something more about enhanced depth imaging, and difference between EDI- Cirrus HD OCT 5000 and EDI Heidelberg Spectralis. I don't understand how EDI technique works "Spectral domain can show to a little extend these deep structures when using a technique known as enhanced depth imaging, by pushing the instrument closer to the eye " . Thank you so much.
@adelabdelshafik3 жыл бұрын
@@kimbich7235 sorry at present time I do not have much information regarding EDI, may be in the future.