Digital video recording of endoscopic procedures in the operating room
By Jacques Bron on Friday, July 18 2008
I have recently been confronted to the need of digitally recording live endoscopic / laparoscopic surgery procedures in the operating room (OR). This challenge had several constraints such as :
- the system should be small and easily tranportable in and out of the OR
- the system should be compatible with most video endoscopy standards and connections used in ORs
- easy manipulation by surgeon or nurse is required
- cost should be low, compared to professional systems that are integrated into video endoscopy / laparoscopy platforms (around $10.000)
- if possible, avoid the need to bring a laptop in the OR
- widely compatible video file format for subsequent video editing
After researching on the web, I found and tested Pinnacle Video Transfer (PVT). This device is small, light and doesn't require to bring the laptop in the OR. Video storage can be any USB 2.0 storage device including a portable hard disk drive, USB flash drive or even an iPod. The PVT provides high-quality MPEG-4 encoding in H.264 at up to 720x480/576 (NTSC/PAL) resolution and supports multiple inputs including S-Video, Composite video and stereo audio.
At $129, this device is much cheaper than professionnal systems proposed by video endoscopy companies (they sell around $10.000). It delivers a video quality that is good enough for scientific congresses and medical / educational web sites.
In order to get the PVT work for me, here is what I have used :
- PVT with its power supply (included)
- S-Video cable (you can find one in any electronics / video store)
- External hard disk drive (Seagate USB 2.0 200 Gb, but you can use any other brand and storage size)
- USB 2.0 cable (usually supplied with the hard disk drive)
This reduced cost solution is very easy to setup and operate. Selecting the right resolution and quality of capture is done by pressing a button. For example, when you use an external hard disk drive you can select one of these three resolutions available :
On an iPod, the highest video quality is 640x480. The maximum recording duration varies depending on the selected recording quality and the recording capacity of the connected USB device. As an example, on a 250 GB drive and with best recording quality, 187 hours of video can be stored. That's more than any long surgery procedure ! Starting and stopping the video capture is a one-touch start / stop button and that makes the system very easy to operate even by non -tech users. Of course, video quality isn't comparable to HD, but what we get here is sufficient for most medical / scientific usage. One little problem I encountered concerned the type of formatting of the external hard disk drive (HDD). The PVT needs to have the hard drives formatted either in FAT16 or FAT32 formats. That can be a problem for people using Windows computers as Windows 2000 / XP / Vista cannot natively format FAT32 partitions larger than 32 GB. I'll explain how I easily solved that issue in another post. Anyway, even if you CAN format your external HDD in FAT32, the files cannot be bigger than 4 GB. When recording a long video sequence (like a surgical procedure), you may need bigger files, as 4 GB in best quality is about 3 hours of video. The PVT can handle this file size limitation automatically by creating a new file each time a capture file has reached the size of 4 GB. The new files are automatically numbered in ascending sequences. During this procedure, a few seconds of video capture are lost. All this is done automatically inside the PVT until you stop the capture or your external HDD is full. Below is a sample capture of a urological endoscopic procedure. The original capture was done with best quality (720x576). It was then edited in Adobe Premiere Elements in order to keep only a short sequencet. The width and height of the movie were then reduced to 436x335 px in order to fit in this web page's design. The resulting file was then exported as a flash (.flv) video movie and then integrated in a flash file (.swf) : Overall, the Pinnacle Video Transfer is a low-cost, efficient and easy-to-use solution for people who need to digitally record videos from sources like endoscopy or laparoscopy. It fulfills the requirements of compacity and mobility we have for use in OR. Of course, this device is also suitable for any other kind of video capture like family or business movies, as it has been originally developed for these markets. Links for products cited in this article : Pinnacle Video Transfer on Pinnacle web site
