Surgeon's Point-of-View (POV) Video Recording

Learning how to video record vivid, stable, high-def, and focussed shots from my (surgeon's) point-of-view has not been an easy endeavor due to technology limitations, though things do appear to be slowly improving. There have been pros and cons with most video-recording systems to date which I have summarized below. The "perfect" video-recording system has yet to be developed which must include all these elements:

• Wearable on headlight or glasses
• Camera located between the eyes that is maneuverable to adjust recording angle
• Head-up view to see what is being recorded real-time
• Manual white balance adjustment

• Manual exposure adjustment (bright lights used in surgery often confuse auto-exposure settings which result in washed-out pictures)

• Auto-focussing with adjustable zoom

• VERY good image stabilization

• HD video-recording

General Problems with Head-Mounted Video Recordings

The problem with current head mounted video-recording systems including Google Glass are several-fold. First of all, no matter how good you think you are staying still, there are constant micro-motions/tremors which produce unusable erratic videos. This annoying camera movement becomes even more pronounced when using cameras with longer focal lengths which is why most head-mounted camera systems come with a fixed, wide-angle lens which unfortunately takes away from the narrow-angle, focussed shot a surgeon would like recorded.

Also, the smaller and lighter the camera, the more inferior the optics resulting in poor video quality (compared to high-resolution, 3CCD, HD recordings which is what the surgeon's want).

These short-comings are common with all head-mounted video-recording systems. Unfortunately, there are even more problems depending the camera.

Google Glass (or any eyeglass side-mounted camera)

Typically, when a surgeon operates, the surgical field (green) is a certain distance from the his/her face. When in a comfortable position, wearing any type of head-mounted camera system located on the side like Google Glass unfortunately ends up video-recording a point that is above and to the side (purple) of what is actually desired.

In order to compensate the vertical offset, either the surgeon has to flex the head more or move the eyeglass down towards the lip.

To adjust the horizontal offset, the surgeon would have to turn and move the head to one side such that the camera has a more direct line shot into the surgical field... but that would mean the surgeon would be operating off-centered, almost looking over one shoulder.

Although doable, this is far from perfect or comfortable.

Central Head-Mounted Video Camera Systems

There ARE video-recording cameras that contain a camera that can be placed centrally over the forehead or between the eyes including Luxtec and SurgeonCam which are mounted on the headlight and PivotHead glasses (among others) where the camera is built into the frame between the eyes.

The headlight mounted systems'  camera angle can be adjusted to provide a more precise POV recording, but the general disadvantages of body-worn cameras still apply with constant erratic motion and wide-angle shots that do not specifically focus in on the surgical field.

The PivotHead glasses do provide perfect central shots, but still suffer from a vertical offset (orange) which cannot be adjusted like the headlight mounted systems.

Overhead Mounted Camera Systems

For the same reason the best photos are obtained by cameras fixed to a tripod, the best videos are often obtained by cameras fixed into position by a stationary object.

One object cameras can be attached to are overhead fixtures.. specifically the operating room lights.

Such cameras are attached typically to the light-handle of such overhead operating room lights which are directed down into the surgical field. Such systems provide excellent focussed, stable, high-quality video-recordings with one BIG disadvantage. The surgeon's head keeps getting in the way.

Also, the light-handle is positioned for optimal lighting of the surgical field... not optimal framing for capturing good videos.

Bed-Mounted Camera Systems

Using a Thompson Laparoscopic Retractor System, the video camera can be attached to one of the articulating arms and adjusted sterilely as needed. Using this retractor system can allow the camera to be positioned independently of the overhead operating room lights and to be as close to the surgical field as necessary.

The video is limited by how good the camera is that is attached. The best one I've been able to find is the Sony HXR-MC1 which incorporates a large-sized lipstick camera that is attached to a controller where manual controls for focus, zoom, white balance, exposure, etc can be made. Other than the built-in LCD screen, there are included plugs (Component, RCA, and with adapter S-Video) that allow what the camera is recording to be thrown up onto a large screen.

Other wireless video lipstick cameras are now being produced, but lack manual controls to adjust zoom, white balance, and exposure. Some offer real-time video display so it may be just a matter of time before all other manual controls found with the Sony HXR-MC1 become more widely available.

The main disadvantage with this setup is that the setup itself can get in the way of the surgeon.

Conclusion

So there you have it... No perfect surgical POV video system yet... Maybe in the next few years if technology keeps moving the way it is.

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Hearing and Understanding ONE Voice Among Many Sounds

Have you ever wondered how is it that a normal hearing human being can hear and understand one person talking in an environment where there are many other people talking just as loudly be it a restaurant, conference, county fair, etc?

How is it that you can hear and understand one particular person over another, even if they are both talking equally loud?

Researchers are just beginning to understand how a human does it... Before explaining, lets use an analogy.

In the past, I used the analogy of an old antenna based radio to explain how human hearing works... A given antenna radio has a volume knob that one can adjust up or down (as would occur with a hearing aid) as well as antenna reception which allows one to get a clear signal vs one full of static.

The ear is like the volume knob and the brain is the antenna... As such, if the reception is bad and there's a lot of background static, a person will have a hard time understanding what is being said on the radio... regardless of whether the volume knob is turned up all the way or not.

Similarly, if the brain is not filtering out the background noise to isolate the sound or person you want to hear and understand, you will have a hard time understanding what is being said.

While the ear indiscriminately hears everything, I've always just stated "the brain" acts to filter out the background noise you don't want to hear, but nobody really understood how, until recently...

Researchers in New York determined that there are different regions of the brain that perform this sound filtration that is completely separate from the auditory cortex (part of the brain that "hears" sounds transmitted from the ear).

Furthermore, the brain areas responding only to the selected voice constantly fine-tunes the reception to allow further improvement in comprehension over time... just like fiddling with an antenna to get as clear a signal on a radio station.

If the brain is not able to properly focus and filter the sound, the individual will have a hard time understanding conversation in a noisy environment, regardless of whether the person has normal hearing or not (for example, in patients with ADHD).

Of course, if hearing loss is also present along with an unfocused brain, it just makes it that much harder (for example, in the elderly who not only have hearing loss, but also decrease in brain function as well).

On the opposite extreme are people who make their living focusing on a specific sound among many sounds and have much greater ease in understanding people talking in a noisy environment. Take professional musicians in an orchestra who excel at hearing a single instrument during a Beethoven orchestral performance.

Source:
Hear That? In A Din Of Voices, Our Brains Can Tune Into One. NPR 3/6/13

Reference:
Mechanisms Underlying Selective Neuronal Tracking of Attended Speech at a “Cocktail Party”. Neuron, Volume 77, Issue 5, 980-991, 6 March 2013

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Revolutionary Camera Takes "Living" Pictures

Lytro has introduced a new type of camera that may have tremendous implications in medical photography.

It is a camera that takes a "living" picture. What does that mean?

In essence, it is a camera that takes a picture taking ALL the light information that is present such that the picture can be manipulated as if you haven't taken the picture yet.

It sounds confusing, but practically speaking, it means that one can literally refocus any part of a picture AFTER it has been taken. We are not talking about photoshopping using the blur or sharpen filter. It is literally refocussing a picture AFTER it has been taken!!!

You need to see it to believe it...

Click here to view some sample pictures. Touch (click) to refocus any part of the picture; pinch (double-click) to zoom.

I can't wait to see some medical photography done with this camera which starts at $399.

Purchase through the company's website.

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