Surgical video – part 1: intraoperative video recording and storage

Introduction

Urology has been ‘ahead of the game’ with

technology, so to speak. Historically, as

urologists, we have been used to working

with endoscopic images for many years

and were probably the first surgical

specialty to be recording endoscopic

surgical video on cine film [1].

With the explosion and expansion of

information technology, instantaneous

dissemination of medical knowledge

across the globe is a reality and is here

to stay [2]. In this digital age, there is an

increasing opportunity for surgeons to

create their own videos for the purpose of

education, demonstration on websites or

social media, and increasingly journals are

requesting or accepting video footage for

publication. The selection of technology

is diverse and can be overwhelming for

the technologically naive. In this first

paper we will cover patient consent for

video recording, video media formats,

equipment needed for capturing video

footage and optimal storage devices.

Consent and ethical

considerations

First and foremost, the surgeon should

obtain informed oral or, preferably, written

consent from the patient to record video

footage of any surgical procedure. The

General Medical Council provides detailed

advice to guide clinician compliance with

these principles. During the consent

process it is important to emphasise to

the patients that their details will remain

anonymised and they should not be

identifiable [3]. Individual hospitals vary in

their requirements to obtain permission to

record video. It is important to make sure

you comply with your hospital’s protocol.

The responsible Caldicott Guardian or

department of medical illustration can

provide more information regarding

live transmission of a surgical procedure,

attempts to record an operative video

should not compromise the operation

itself. As with anything in the operating

theatre, precautions for sterility must be

taken. Appropriately counselled patients

may appreciate the opportunity to

contribute to medical science [2].

In our hospital, we routinely record

live urological procedures including

laparoscopy, cystoscopy and robotic

surgery. We consent all patients and

record all robotic surgery to hard disk.

Operations are deleted as the disk

becomes full, unless there is a particular

reason to archive the video footage such

as unusual anatomy, surgical procedure or

complication. At the patient’s request, we

will burn a copy of the operation to Blu-ray

disc.

Input

Video and image recording in urology are

beneficial in laparoscopy, cystoscopy and

robotic surgery. These require dedicated

stack systems provided by companies

with a wealth of experience in this domain

including Karl Storz, Olympus, Richard

Wolf and the DaVinci robot to name

but a few. The quality of the recording

will obviously depend on the camera

attached to the stack system. A look at

the back of a stack system will reveal a

vast array of connections and sockets

(Figure 1). These convert an analog video

Figure 1: Rear view showing input and output sources on a video capture device.

Surgical video – part 1:

intraoperative video recording

and storage

The use of digital technology has progressed in leaps and bounds and nowhere is

this more apparent than in medicine and surgery. Footage of live surgery is now

easily accessed on the internet or displayed at conferences. Thus, the 21st century

urologist needs knowledge on how to skilfully capture live video footage for the

purpose of education, demonstrations on educational websites, publication in

electronic format, or consent. The selection of technology is diverse and can be

overwhelming. The purpose of this two-part series is to guide the inexperienced

urological surgeon in the fundamentals of recording, storing, editing, animating

and production of a definitive surgical video for either publication or teaching.

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signal into an image displayed on a video

encoded screen. Screens in Europe are

encoded to display colour images via

PAL or SECAM. NTSC was the standard

in North America until 2010, and is being

phased out in favour of ATSC (aka HDMI)

thus it would be wise to check screen

compatibility for other parts of the world.

The standard analog video is transmitted

as a composite video (one channel).

For better signal transmission with full

colour, a two-channel (separate video aka

S-video) or three-channel (component

video) connector is required. However,

none of these carry audio signals. From

the year 2000, digital visual interface

(DVI) was introduced for the transmission

of uncompressed digital video signal.

Further development has now resulted in

the serial digital interface (SDI) and high

definition multimedia interface (HDMI)

for transmission of high resolution video

signals.

Screen resolution

There are many resolutions available to

record your videos. Before you record

video, you need to know the target

medium on which the footage will be

replayed. The resolution needed to replay

video on a smartphone is much lower

compared to being displayed on a 10

metre-wide screen in the auditorium of

the plenary session at an international

scientific meeting. If there is any

possibility that the video footage being

recorded will ultimately be part of a

surgical paper or presentation, it makes

a lot of sense to record in the highest

resolution available. It is very easy to

decrease resolution of recorded video, but

impossible to increase resolution. Table

1 summarises resolutions available for

video capture.

Aspect ratios and their usage

The aspect ratio is the shape of the

rectangular display of the video. This can

differ widely depending on the intended

use of the video, for example displaying

on YouTube versus a wide-screen

television. Getting an appropriate aspect

ratio will prevent mishaps such as having

a video that looks too stretched out

horizontally or vertically.

Many recording formats have a

variety of aspect ratio options. Table

2 lists some example ratios and their

most appropriate usage. The numbers

represent the relation between width and

height (x:y respectively).

A device that can record in HD is

obviously more desirable. One must

then consider the output file format and

whether this would be compatible for

dissemination. Popular video formats

include Movie Picture Experts Group

(MPEG) 1, MPEG-2, MPEG-4, Audio Visual

Interleave (AVI), Windows Media Video

(WMV) and movie (.mov). WMV is coded

by Microsoft and developed mainly for

PCs with Windows operating system

(OS). AVI has cross-compatibility for

Macintosh (Mac) OS, however it is poor

for compressed video files. MPEG-4 is the

most widely used format for interactive

high quality audio and video capture

and playback for the internet. This may

sometimes be expressed as H.264/

MPEG-4 AVC. The coding standard

H.264 or advanced video coding (AVC)

has been developed to maximise video

compression [4]. This permits smaller

video file sizes with no loss of quality. It

has been adopted in many commercial

applications such as Blu-ray, closed

circuit television, terrestrial TV, satellite

TV and internet protocols. This versatility

is an added benefit as it is compatible

with most operating systems including

Windows or Mac. It supports resolution

up to 1080p however the quality may vary

by device.

Images and stills can be taken during

the video capture or while editing. These

will be explored in our second series on

editing software. Formats include JPEG,

TIFF, BMP to name a few.

Hardware

For the sake of ease, this paper assumes

the computer platform will be Apple OS.

Since their product line includes video

editing software and supports a wide

variety of file formats, it is a good choice

for the novice video editor. Following a

comprehensive review of the available

technology, we present a range of devices

to suit every budget.

Non-medical grade capture devices

Simple non-medical grade external

video capture devices include video CD

recorders such as the Sony VCD – VD20 or

latterly 1080p HD video recorders. These

have now been superseded by digital

technologies such as smartphones and

head-mounted devices like the GoPro

Hero [5].

For easy recording on the go, portable

Table 1: Resolutions available for video capture.

What is it? Maximum

resolution

Aspect

ratio

30 min

video

file size

Comment

SD Standard

definition.

Less

resolution

than HD.

640 x 480 4:3 ~300MB Good for

smaller displays

like YouTube,

smartphones,

websites with

low-data

requirements.

HD Finer

resolution

than SD.

1920 x

1080

16:9 ~3GB Fits most standard

widescreen

televisions and

displays.

Three-

dimensional

video.

1920 x

1080

16:9 ~30GB Increases depth

perception.

Capturing robotic-

device video.

4K Ultra-HD. 4096 x

3112

1.9:1 ~600GB An upgrade to

HD technology.

Appropriate for

high-quality

television and the

latest and widest

screens. Not in

standard medical

grade, yet.

Table 2: Aspect ratios in width to height.

Aspect Ratio Appearance Compatible devices Comments

3:2 ‘Tall devices’ iPhone 4S and earlier. Superseded.

4:3 Standard definition Televisions, computer

monitors, iPad.

Old standard for

televisions, still

good for websites.

16:9 Widescreen Widescreen televisions,

iPhone 6/5S.

Supported by

YouTube.

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non-medical grade video capture devices

such as the Elgato Video Capture device

(Figure 2) perform admirably for capturing

analogue video. As most stack systems

have composite and S-video outputs as

well as audio, it is ready to plug. A SCART

adapter is included in the package.

Through an output USB port, the device

may be connected to a laptop or external

storage device for real time recording

as the internal memory is limited to one

gigabyte (GB). The preloaded software

makes it easy to record, capture stills and

upload to YouTube. Although best for Mac

users with dual core processor at 2.0GHz

or higher, it is compatible with Windows

7 and above, but not Vista or XP. Suitable

alternatives include the Diamond One

Touch VC500 or the Dazzle DVD Recorder

HD by Pinnacle. These devices cost less

than £100, are portable, easy to plug and

capture from virtually any video source

with HD quality.

Medical grade video capture devices

This is a burgeoning field as robotic surgery

with the 3D Da Vinci robot continues

to expand in the UK. It is important to

note that these recorders are designed

to be attached to cameras; hence the

compatibility with already existing

equipment is key. They all have a range of

inputs and outputs for recording and are

user-friendly.

MediCapture offers the USB 170, USB

200 and USB 300. They are easy to use

and work with existing medical equipment

including ultrasounds, endoscopes and

surgical microscopes. Only the USB 300

allows HD recording onto a 320GB internal

hard drive [6].

The SDC3 from Stryker has a user-

controlled touch screen and allows

simultaneous recording from two sources.

It offers the largest internal storage

capacity (1TB), and multiple output

formats including Blu-ray, DVD, iPad and

USB. It can be fully integrated wirelessly

onto your hospital’s PACS or image

management network. The Karl Storz

AIDA Compact Neo offers similar qualities

[7].

The Olympus IMH-20 (Figure 3) is a

stand-alone HD recording device. It offers

simultaneous image recording from up to

two sources as a single or separate file onto

a dual touch screen display panel. Another

advantage is synchronised voice recording

with video, although this can be added

later with video editing software. Patient

data can be added via the touch screen

panel on the recorder for easy search and

retrieval. More than 70 hours of SD and

HD recording are possible onto its large

500GB internal drive. Alternatively, DVD,

Blu-ray, USB flash or portable HDD are

compatible optical media for distribution.

Finally, the recorder is compatible with

Olympus’ system integration if already set

up for image management. The IMH -10, an

earlier model, exists with 320GB internal

disk space and no touch screen display [8].

The HVO – 3000MT (Figure 4)

manufactured by Sony is a 3D HD recorder

capable of simultaneous recording and

streaming of live video footage. At the

press of a button 30 hours of 1080i video

footage can be stored onto its 400GB

internal hard disk drive (HDD). With a wide

array of inputs, it supports SD, HD and 3D

sources. MPEG-4/H.264 AVC compression

is used and the output can be distributed

onto Blu-ray disc, DVD or USB flash or

portable hard drive. The device can be

connected to the hospital’s servers or run

Sony’s OPSIGATE image management

system for easy access and storage of

patient data. It comes equipped with a

remote control but additional accessories

can be purchased separately such as a foot

switch to improve workflow management

[9]. Obviously, 3D camera heads, monitors

and printers are required to make full

use of Sony’s 3D recording capacity,

nevertheless the HD and SD capabilities

of the HVO-3000MT remain. A suitable

alternative would be the Sony HVO –

1000MD that offers similar specifications

without 3D recording.

Storing your video, what to

expect

As a general rule, more is better! If your

video is in the latest 4K format, expect to

have storage in the terabytes (1000GB).

Portable USB drives are simple to use. USB

3.0 is the fastest for data transfer which is a

consideration if using many 4K videos.

Conclusion

Video capture in the operating room is

possible using a range of portable or stand-

alone units. We have provided an overview

of current video capture devices available

on the market, ranging from the affordable

to the latest technology 3D recorder.

Table 3: Summary of non-medical grade capture devices.

Type of

capture device

Quality you

can expect

Approximate

cost

Comment

iPhone 5S 1080p HD video

recording

£500 Video capture with lens

and storage all in one.

GoPro Hero3 1080p HD video

recording

£300 Video capture with lens

and storage all in one.

Waterproof casing,

potentially autoclavable.

Sony, Panasonic,

Sharp, Canon HD

video recorders

1080p

HD video

recording

£600 An inline device that

easily captures video.

Will export direct to

iMovie, YouTube.

Figure 4: The Sony HMV – 3000MT 3D video recorder.

Figure 2: The Elgato video capture device.

Figure 3: The Olympus IMH – 10 and 20 video recorders.

“Patients may

appreciate the

opportunity to

contribute to medical

science.”

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Table 4: Summary of the features of different video capture devices.

Elgato MediCapture

USB 300

Olympus

IMH-20

Sony HV0-

3000MT

Stryker

SDC3

Karl Storz AIDA

Compact Neo

Video input RCA stereo,

SCART,

S-video

Composite,

S-video, DVI,

HD-SDI

Composite, DVI,

HD/SD - SDI, Y/C

Composite,

3G-SDI, HD/SD

- SDI, S-video,

DVI

RGB,

Composite,

S-video, DVI

Composite,

RGB, DVI-D,

S-video, SD-SDI

Audio

included?

Yes, 48kHz,

AAC format

Not specified Yes Not specified Yes Yes

Video

recording

format

NTSC,

SECAM,

PAL, PAL/60

video

MPEG-4,

AVC/H-264

MPEG-4, AVC/H-

264

MPEG-4 AVC/H-

264

MPEG-2,

MPEG-4,

AVC/H-264

MPEG-2

Compatibility

YouTube

iPad

iPod / iTunes

Yes

N/A

Yes

N/A

Yes

N/A

SD recording Yes Yes Yes Yes Yes Yes

HD recording MPEG-4 or

H.264 bit

H.264 MPEG-4 MPEG-2,

MPEG-4

MPEG-2,

MPEG-4,

AVC/H-264

MPEG-2

3D recording No No Yes Yes No No

Resolution

(aspect ratio)

640x480

(4:3)

640x360

(16:9)

1920x1080i

(16:9)

1920x1080i

(16:9)

720x480i (4:3)

720x576i (4:3)

1920x1080

(16:9) 720x576

(4:3)

1920x1080p

(16:9)

1920x1080p

(16:9)

Capture

stills?

No Yes - JPEG/

TIFF/BMP

formats

Yes - JPEG/TIFF/

BMP formats

Yes - JPEG/TIFF/

BMP formats

Yes - JPEG/

TIFF/BMP

formats

Yes - JPEG/BMP

formats

User

interface

Nil 2.5in LCD

screen

7in LCD touch

screen

Buttons on front Touch

screen

Touchscreen,

USB silicone

keyboard

Output USB DVI Composite, Y/C,

DVI, HD/SD-SDI

Composite,

S-video, DVI,

3G/HD/SD-SDI

DVI DVI-D, SD

Software iMovie

preloaded

Not listed Not listed Not listed Not listed DICOM/HL7

Connectors

included

Yes Yes Not specified Remote control Not specified Yes

OS Mac OS

x10.5.8 or

later

Network,

Ethernet

Ethernet Ethernet Ethernet,

Wifi

Windows XP

Professional

Internal hard

drive capacity

1GB 320GB 500GB 500GB 1TB 1TB

Storage

options

/ optical

media

External HD

drive

Internal HD

drive, USB

flash / external

drive

Blu-ray, DVD,

HDD, USB flash

or external HDD

Blu-ray, DVD,

internal HD

drive, USB flash

or external HDD

Blu-ray, CD/

DVD, iPad,

USB

CD, DVD, USB

USB 2.0 USB 2.0 (3) 2.0 (2) 2.0 (4) 2.0 (2) 2.0 (4)

Dimensions

and weight

92x52x12mm

68g

240x211x63mm

1.8kg

370x167x413mm

~10.7kg

305x410x115mm

8.4kg

N/A 304x163x355mm

6.0kg

Cost* ~ £90 ~ £3-5K ~ £10–15K ~ £13K ~ £15-18K ~ £13K

*All list prices are estimates – please contact the company directly.

We recommend you ‘future proof’ your

investment. Consider compatibility with

the already available equipment, ease

of access, data transfer and ultimately

patient information safety. For projection,

bigger is better – always record at the

highest resolution onto at least 500GB

USB portable hard disk. Ultimately, for

best results when editing, invest in a Mac.

References

1. Blandy JP, Notley RG. Transurethral resection. 4th ed. St.

Louis, USA; Oxford: ISIS Medical Media; 1998.

2. Rao AR, Karim O. A benedictory ode to urological live

surgery. BJU Int 2013;112(1):11–12.

3. General Medical Council. Making and using visual and

audio recordings of patients [Internet]. 2011. Accessed

from: http://www.gmc-uk.org/guidance/

ethical_guidance/making_audiovisual.asp

4. Wiegand T, Schwarz H, Joch A, et al. Rate-constrained

coder control and comparison of video coding

standards. IEEE Transactions on Circuits and Systems for

Video Technology 2003;13(7):688–703.

5. Bizzotto N, Sandri A, Lavini F, et al. Video in Operating

Room: GoPro HERO3 Camera on Surgeon’s Head to

Film Operations – A Test. Surgical Innovation (Internet).

2013. Accessed from: http://sri.sagepub.com/cgi/

doi/10.1177/1553350613513514

6. MediCapture - MediCap Model Comparison. Accessed

from: http://www.medicapture.com/medicap-model-

comparison.php

7. Digital Documentation – SDC3: Stryker. Accessed

from: http://www.stryker.com/enus/products/

Endoscopy/VisualizationandDocumentationSystems/

DigitalDocumentation/SDC3/index.htm

8. imh_10_20_family_brochure__en_001_v1_20111026

(1).pdf.

9. Sony HMV 3000MT brochure. Accessed from:

http://www.sony.co.uk/res/attachment/

le/64/1237489007464.pdf

Gaël Nana,

CT1 Urology,

Department of Urology,

Wexham Park Hospital,

Slough, Berkshire, UK.

Charisse Colvin,

Medical Student,

Department of Urology,

Wexham Park Hospital,

Slough, Berkshire; and

American University of the

Caribbean Medical School.

Omer Karim,

MS, FRCS, FRCSUrol,

Consultant Urological Surgeon,

Department of Urology, Wexham Park

Hospital, Slough, Berkshire, UK.

omer[email protected]om

Declaration of competing interests:

None declared.

Declaration of competing interests:

None declared.

Declaration of competing interests:

None declared.

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