Before starting a case, the surgeon using either device must ensure that its battery is fully charged, as a full charge typically supports 1 hour of continuous recording (the Google Glass battery is a lithium-ion 670-mAh internal unit). A full charge should be enough to capture a short case. Newer GoPro models, with a battery listed at 1050 mAh, provide 1 to 2 hours of recording. When more than 1 hour is needed, an external USB battery pack can be used. This pack allows the device to remain plugged in throughout the case (the pack is kept in the surgeon’s back pocket). We recommend having an external battery pack that is at least 10,000 mAh (~$30 online retail), which easily provides 3+ hours of recording. Unfortunately, this arrangement can be cumbersome. Alternatively, with GoPro, additional batteries may be purchased, but the user needs to dismount the device in order to swap them in (may be difficult during surgery). With both units, partitioning a video into shorter segments conserves battery power and minimizes the risk of file corruption, which may occur if the battery dies or the device overheats.
Google Glass users can bypass manual operation of the device by giving it voice commands (eg, start video, take still image). The exception is for recording video for more than 10 seconds (current default setting). Unfortunately, the surgeon must touch the device to start this recording, which means using extra gloves to preserve operating field sterility. Still images can be made through a combination of voice and head gestures and without manual intervention (Figure 2). Last, users must ensure that the device is not actively connected through Bluetooth to a mobile phone, as incoming calls, text messages, and e-mails may disrupt active recording and become a distraction. The connection can be deactivated by disabling Bluetooth on the host smartphone or by placing the phone into airplane mode and turning off Wi-Fi.
Google Glass users can see what is being recorded through the viewfinder prism, whereas GoPro requires precise framing of the video before recording. Framing is done by grossly aiming the device in the desired direction. However, there is no way to ensure exact aim during recording. If at any point during a case there is slight repositioning of the GoPro, there is a risk of recording the case out of the center of view. An important advantage to newer GoPro versions is the ability to control the device through a wireless remote that can be placed under the surgeon’s gown. The remote can be used to pause and resume recording, without changing gloves, as is done with Google Glass. Last, because the minimum viewing distance from the surgical field is usually 18 inches or more, typically there is no loss of focus or blurring of the image from short-distance recording on either device.
3. File management and playback
Before using wearable technology in the operating room, surgeons must become aware of its limitations with respect to file storage and playback. Google Glass has a usable memory of about 12 GB (1 hour of video may require 1.5-2.0 GB). Conversely, GoPro’s capacity is defined by the micro SD card used. Therefore, the Google Glass hard drive must be regularly maintained well before being brought into the operating room, whereas recording can be extended (with respect to memory) for the GoPro if the media card is large enough.
Both devices allow for wired file transfer, which may be done with Windows Explorer (PC) or iPhoto (Macintosh). However, Google Glass also allows for wireless transfer, through portable storage supported by Google. Although this type of file transfer may be convenient for short, everyday clips made outside the operating room, it is prohibitive for surgical media, mainly because of patient privacy concerns. With wireless transfer to a nonsecure cloud platform, there is a risk of breach of patient confidentiality. We therefore recommend against using wireless upload when producing surgical multimedia, as patient identifiers are likely to be included in the recorded audio or video contents. Conversely, with GoPro, the micro SD card can be used as a portable hard drive to transfer files to a laptop or media reader, obviating the need for wired or wireless transmission. Last, when using traditional wire transfer or memory card to upload to a hard drive, users must ensure that the drive complies with patient privacy laws and regulations.
4. Privacy and patient consent
As mentioned, great care must be taken to ensure that patient privacy laws are followed. This is especially relevant with content uploaded to online cloud storage, as with Google Glass. The upload may occur automatically if the unit is connected to a Wi-Fi hotspot. In addition, when using surgical media for a real-time webcast for education or demonstration purposes, surgeons must ensure that no protected health information is broadcast and that the patient and the surgical team are aware of the webcast and its purposes.