We are interested in constructing an intrinsic optical imaging system to investigate changes in cortical blood flow. The simple versions of this procedure - look relatively straight forward to put together but the devil is always in the details.
not yet heard about that but it sounds like a great idea.
I heard from Cornelius Farber that they used a fiber optic to monitor fluorescent dyes. So you might like to contact him directly since it is only guessing from my side (http://www.uni-muenster.de/OCCMuenster/members/cornelius-faber.html)
I'm routinely using the setup by Val Kalatsky (Kalatsky & Stryker 2003, Neuron), but although I know a bit about programming, I couldn't have built it myself. The problem, from my point of view, is to extract the relevant information from the data flow (provided that you go for periodic imaging, which would seem reasonable). The hardware, in contrast, is rather straightforward and can easily be built by an able workshop. I suppose you know the relevant papers - else, you're welcome to ask.
Is purchase not an option for you? I'm not sure whether Val still sells his setups; his web page seems to be down (at least, I don't find it). Instead, a google search for "val kalatsky imaging" renders a free download as 10th hit. But loading the page is just failing, so I can't tell you whether it is what you need.
We, like Konrad, use a system very similar to Kalatsky and Stryker with great success. Collecting the images isn't as big of a deal as doing the proper analysis. We have a series of lab written MatLab scripts that do the job for us. How successful your system will be is very much dependent on the camera involved.
Optical Imaging Inc actually sells entire setups for doing what you are looking for. I suggest taking a lock at their products, but we are actually going to be building a second system soon so I will see what information I can gather for you.
Our lab has done quite a bit on this, with laser speckle imaging and camera-based imaging in general. This PDF discusses functional optical hemodynamic imaging of a dorsal window chamber model, but it is just as usable for cerebral imaging.
It all depends on what kind of changes you want to image, Rohan. If you want to look at flow in blood vessels during surgery, Novadaq and Carl Zeiss have systems that image indocyanine green fluorescence. If you want to look at overall changes, non-invasively, then there are a range of options depending on whether you want more surface information or deep information. Diffuse optical tomography is good for deep information. I was going to suggest you check the work in this area from Beckman Laser Institute at UCI, but I see Bernard Choi has also responded. You could also check Sergio Fantini's group at Tufts University and David Boas' work at Harvard University. http://ase.tufts.edu/biomedical/research/fantini/researchAreas/BrainImaging.pdf
In terms of analyzing periodic data, as mentioned by some of the posts above, please see my and Takeshi Yokoo's 2011 paper in J. Neurosci. Meth. I have worked on analyzing intrinsic signal (and other) data and that paper presents a good method for getting low-noise estimates of periodic signals in multivariate data.
It could take a while to frame my next set of questions as I am still making my way through the http://www.weizmann.ac.il/brain/grinvald/pdf/invivoscreenweb.pdf document. Thanks, Kamil.
At this stage an Electrical Engineer at our University and I have started working on the project. From our initial coverage of the literature we are leaning towards establishing a tandem lens macroscope style system, with appropriate wavelength LED's, in a ring configuration, being switched by a trigger delivered from the camera in order to pick up changes in oxygenated and non-oxygenated hemoglobin over time. We are a little bamboozled by the CCD choice. Many of the papers describing this technique have used a Dalsa 1M30/60 camera. However, CCD technology appears to have moved on significantly since these CCDs were first released. For instance CCD Area Acquistion CCDs now seem to be able to achieve frame rates = 180/s at 1024x1024 pixels. With that said obviously good results have been achieved with existing technology - and foremost in our mind is the quality of control software that will interface with the camera.
I would be very interested in your collective opinion about the broad direction we are heading in.
basically, I think that it would be helpful if you could specify what parameter you want to measure. Coming from my own perspective, I have silently assumed that you are interested in neuronal activity measured via blood oxygenation. Some answers, however, indicate that optical imaging can as well be used to study the cortical blood supply itself - which would make a large part of my first answer irrelevant.
And this may also hold true for your question concerning the frame rate. For the acquisition of cortical topographic maps, we are even binning down our frame rate by a factor of 4, i.e. to 7.5fps. Changes in blood oxygenation are slow. Moreover, the amount of data would explode our system if we didn't bin. But that may be different if you are interested in fast capillary changes or the like.
It depends of your material resources. The fastest way is purchasing one of the commercially available systems, but to build in the lab - it is much cheaper. A Few years ago, I used Cascade 512b camera (Roper Scientific) and HAL-100 light source , light shutter and set of filters (green and red). But the situation on the market changes very fast so now some new parts are available. We can use LED as a light source. We used Metamorph to control the system. Now we have a MiCAM, we are working with voltage-sensitive dye but it is also suitable for intrinsic imaging.
If you need some details please do not hesitate to e-mail,
Yes, we are interested in the actual blood supply, flow and O2 consumption. We would find it useful for identifying regions of motor cortex that we are interested in. We would also like to develop a BOLD system approach for examining changes in cortical connectivity. Similar to that described by: http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016322
We have started getting quotes on area scan CCD's for the system - we really like the look of the DALSA 1M60 - its used in quite a few IOS studies, its 1024 x 1024, 12 bit, 60 fps (spec sheet attached). Therefore, it would lend itself nicely to mutlispectral imaging. However, I nearly fell over when the Australian distributor told me that the 1M30, which is half the frame rate of the 1M60 was going to be $9000 plus a `$2000 frame grabber card - when he told me this my mind was so blank that forgot to ask how much the 1M60 was going to be, but presumably quite a bit more.
Zhang and Murphy, in their beautiful 2010 paper (http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0050119) report using both the 1M60 and Sony XCST70. The XCST70 is quite a bit cheaper ~$1000 has the same frame rate (~60fps) a lower res = 768 x 494 and lower bit depth (8). From the Weizmann paper I understand that bit depth is more crucial then resolution, and Murphy appears to have developed a workaround for this. In an earlier paper (Journal of Neuroscience Methods 182 (2009) 211–218) in relation to the Sony they report:
"[using the] the 8-bit dynamic range [of the Sony] we collect images at relatively high frame rates (30 Hz) and collapse across time to effectively boost well capacity. To increase signals further, we also integrate light from multiple stimulation trials and in space when regions of interest are used for calculations, and always perform calculations with 32-bit precision"
Basler seem to have a reasonable in-between option in the 'Pilot' series camera:http://www.baslerweb.com/products/pilot.html?model=137 with 1024 x 1024, 12 bit at 60fps at cost of 4K + 1K framergrabber card. The catch here is that the Teledyne Dalsa camera comes with software that has an accessible - intuitive GUI - whereas with the Basler you get the camera drivers and a pleasant smile from the sales team.
Any suggestions on how we should proceed with this decision???
Sony spec sheet:http://pro.sony.com/bbsccms/assets/files/mkt/indauto/Brochures/is-1104.pdf
Hi, I am using the Grinvald system (optical imaging inc) I would like some advise of how to analyze those images, I'm quite lost, I've never done any signal processing, any idea of where can I find a more user friendly approach to analyze them?
There should be a software with the grinvald system that should allow you to do basic analysis and get an idea of what it is about. But data analysis also mainly depends on what protocol you are using (episodic vs continuous stimulation), voltage sensitive dye or intrinsic optical imaging, or even the species.
Probably my comment is too late, but anyway, here it goes. If you are looking to image the cerebral blood flow through laser speckle imaging, you do not need a super-fast frame grabber. Remember that the hemodynamic response has 4-5 seconds duration (in rodents), so anything with 4-5 fps will do for you.
The most important issue for you is to get a 12-bit camera with good noise performance at fast shutter speeds (~10ms). The group of Dr. Lesage has published several papers using a CS3960DCL, Toshiba Teli camera and lately, another system with the Pantera 1M60, DS-21-01M60-12E, Teledyne Dalsa. This latter camera is supposed to be newer and better; however, its performance is not as good as the Toshiba (in terms of SNR), nonetheless it gets the job done. A drawback of the Dalsa is that a saturated pixel will saturate a whole line in the image, so we have to pay attention to hot spots, even if they are outside the FOV of interest. Hope it helps
I've built one before with a qimaging camera for $12,000. Now that the Basler Ace cameras are out, I'm going to try an acA1300-30um Monochrome. USB3 interface. $695 from Edmund Optics. Use free ephus software from Svoboda lab that runs in matlab for the frame triggering, data acquisition and data processing. Should have the whole rig built for under $3k. Will post a build to my blog once its done. Cheers.