Cirrus Suggestions

Fri, 13 Jan 2017 18:58:34 GMT

Hi All

Looking for input from Cirrus users. (we use a 5000)

When capturing a volume scan (512x128), as you get to the final few b-scans, the live view of the B-scan will begin to flicker rapidly between the scan it's capturing and what appears to be the central scan line. With a good patient, this is very brief and the scan will complete.

On a patient with marginal fixation or view, this flickering may last a few seconds or longer, but again eventually completes.

I've accepted that this is normal behavior.

NOW - on a POOR patient, where the entire scan may takes >60-90 seconds the flickering on the final scans will slow down substantially and the completion seems to taken forever, even relative to the already slow B-scan capture rate.

I'm curious if anyone knows the explanation of why the display of the flickering scans (and presumably the actual capture) slows down and if there's a way to address it. I've been pondering the theory that there is some sort of buffer than is being exhausted by the looooong capture time and if there was a hardware fix i could try (increase buffer allocation, more RAM etc).

I guess while i'm asking, validation that this flickering is "normal" would be good.

Thanks!

Fri, 13 Jan 2017 19:17:08 GMT

Jim this may be the high resolution horizontal and vertical BScan that is taken on all of the Zeiss cube scans.

If you have a patient where scans are taking 60-90 seconds something may be amiss. i have rarely seen scans take this long. When the tracking has issues you have the option to turn it off - which may actually be preferential on difficult patients. The other thing and I have noticed many people don't know this so I'll toss it out there, when the tracking is scanning you can use the mouse, mouse wheel and/or keyboard to recenter, z-offset, and stay within the pupil - basically driving the scan while it is capturing.

What software version are you running? Perhaps I can send you an updated version.

Fri, 13 Jan 2017 19:24:15 GMT

I have an older software version but from what I've seen with demos it sounds like it may be the tracking when you take an OCT. The machine is trying to keep matching up with the initial reference image it captures a the beginning and if patients have movement (especially small movements from nystagmus.) or media opacity issues it makes it that much more difficult for the machine to keep up to capture the image. In those situations you could try to turn the tracking off if that's possible. You might end up with motion artifacts and blinks but it should capture them faster so even if you have to retake they shouldn't take as long. Just a suggestion but it might be something to look into.

Mon, 16 Jan 2017 16:11:23 GMT

I think it happens in all cube scans at the end of the scan. If it is a difficult patient, I just tell them that I can tell it is almost finished, and blink quickly and fixate.
Libba

Tue, 31 Jan 2017 00:42:55 GMT

This happens often with poor fixation or media opacities, first thing I do is "drive" the scan like Mike said, if that doesn't work, cancel the scan and rescan w/o tracker, making sure you have a descent scan. We are a big practice and can't afford spending 60-90 secs on 1 scan, I'm sure you don't either.

Good luck

Andy

Tue, 31 Jan 2017 15:58:51 GMT

Yes Andy et.al. - often with inconsistent fixation or marginal view, but occasionally on a "regular" patient, but the hesitation is fairly brief. And yes, we actively scan almost all of our patients. As a tertiary care university setting, we see a large number of end-stage referrals and Peds patients 3 yo and up. So these are the situations were the extreme scan times and flickering are the worst. Canceling and re-scanning is a very bad choice after you've invested the time into getting that far - and the reality is that i probably won't get anything better. No-tracking isn't an option because the data is virtually useless due to the amount of eye movement.

Thanks for all the input. Has anyone resolved the end-scan flicker issue with a hardware or software upgrade? ( we are at v. 7.6.0.118 on a 5000)

j-

Wed, 1 Feb 2017 20:45:59 GMT

Jim send me your OCT 5000 Serial Number via email and I will send you the 9.5 software. The eye tracking for the 5000 is vastly improved with the release of the OCT Angiography in 9.0 version. I can have 9.5 shipped to you.

Fri, 28 Apr 2017 20:39:47 GMT

Jim,

I would agree with the other posts and trying the new software. Also, I use the FastTrac about 70% of the time. Sometimes the patient can hold steady and not blink for 2-3 seconds, but not much longer. Also, the 200 x 200 scan is about 2 seconds vs. the 3 seconds for the 512 x 128.

Artificial tears can help with patients who blink too much.

Be aware, if you do the Ganglion Cell Analysis, each macular scan has to done at the same resolution to be printed on the same page.