Referencing CT Scans Through a Headmounted Optical Display During Laparoscopic Surgery

Helena M Mentis, PhD¹, Ahmed Rahim, BS², Pierre R Theodore, MD². ¹University of Maryland, Baltimore County, ²University of California San Francisco

Introduction

With the increasing use of imaging systems in the OR, each with its own display, it is an ever-growing challenge to have the required image on the appropriate display. Having the required CT scans or X-rays in the surgeon’s field of view without having to adjust the orientation of displays or turn away from the patient would provide an immense benefit in maintaining attention on the patient and task. This would provide a benefit in both OR design as well as surgical outcomes. We present here a head-mounted optical display to show CT scans to assist in laparoscopic surgery.

Methods and Procedures

For this trial, the Vuzix M100 was used. As opposed to the Google Glass, where information is projected onto a transparent ‘window’, The Vuzix M100 uses a miniature color-LCD that presents the image without visual interference. An external portable battery pack enabled the surgeon to use the device for extended periods of time.

The head-mounted optical display has been used in 40 complex minimally invasive cardiothoracic surgeries – i.e. CT images would be needed intraoperatively. A CT image chosen by the operating surgeon was preloaded onto the head-mounted optical display’s computer to be placed in the periphery of the surgeon’s point of view and referenced when needed. The surgeon took notes after each use to capture benefits and hindrances to the display’s use.

Figure 1. The Vusix M100 head-mounted optical display: diagram (on left) and in use (on right).

Results

Having the images at the surgeon’s disposal was deemed quick and easy to use. For instance, in using the system to pinpoint the exact location of a lesion that was buried deep in the lung, the surgeon was able to glance at the images displayed on the system and then quickly reorient his vision back to the laparoscopic video. There was no record of fatigue from wearing the device throughout the surgery. It was also noted that, as the display was not in the direct line of site, it did not obstruct the field of vision. When needed, it was easy to glance over and switch attention between head-mounted optical display and endoscopic display across the table.

The system’s hindrances were due to its design for consumer markets as opposed to one specifically designed for surgery. First, the display’s default is to enter standby after two minutes. In those situations, a nurse was called over to reactivate the display by touching the power button on the side. Second, there was no sterile mechanism for cycling through CT scans. Finally, the head mounted optical device competed for space with glasses, loupes, or a facemask.

Conclusions

Although there were some hindrances, the head-mounted optical display was useful for complicated laparoscopic cases. However, further work needs to be conducted in order to seamlessly integrate the display into the OR. The most important feature that we are addressing is the use of verbal commands and gestures to interact with the images and the display.