*6.2.2 Use of augmented reality to localize tumor lesions*

Accurate localization of intracranial lesions before surgery is important, but sometimes difficult. Modern navigation systems are very useful, but expensive.

A low-cost solution for locating brain lesions and their surface projections in augmented reality has been described by a Chinese team. They used an iPhone to partially achieve this goal and assessed its accuracy and feasibility in a clinical neurosurgical setting.

This low-cost, iPhone-assisted, image-based augmented reality solution is technically feasible and useful for the localization of certain intracranial lesions, in particular superficial supratentorial intracranial lesions of medium size [54].

#### **6.3 The smart scope**

Another technological revolution should be mentioned: endoscopes Smartphone cameras, or otherwise called "Smart-Scopes".

In this case the Smartphone replaces the endoscopic camera and monitor by using its own camera and screen. The endoscope is coupled to the Smartphone camera and a removable light source completes the device. The Smartphone will be protected by a transparent sterile bag. The result is another laparoscopic surgical device called the smartscope that offers portable, cable-free, low-cost laparoscopic visualization.

Since the Smartphone used will mainly provide its camera to the surgical device: the higher the quality of the camera (4 K and 3D), the better the image of the surgical site. The size of the Smartphone is not important since the image obtained is immediately casted via Wi-Fi on a larger monitor. The image transfer is instantaneous and keeps the native resolutions.

The part that adapts the Smartphone to the endoscope can be made from an old, unusable camera head or purchased new. Different models are available on the market; some are specific to certain smart phones.

Removable camera sources are available on the market. Their disadvantage is that they have a limited life span.

The main advantage of this system is that it does not require any wiring. The image obtained on the Smartphone screen can be directly casted via Wi-Fi on a large monitor. It is a stand-alone system that completely dispenses with expensive laparoscopic columns. The surgeon holds the device and stands behind the Smartphone to watch the screen.

Real-time transmission of the image can be done through media streaming devices (such as Chromecast and Airplay). The device is plugged into the HDMI port of a TV and communicates, via Wi-Fi connection, with another Internetconnected device (computer, Smartphone, tablet, etc.), in order to display the received multimedia content on the TV [55].

The Smartphone therefore benefits from the power of the new cameras fitted to high-quality smart phones. As their cameras are constantly evolving, they allow high-definition images with true-to-life colors to be obtained. 4 k cameras are now available in many smart phones at much more affordable prices than 4 k-ultra HD laparoscopic columns.

The only limitation to this system is the limited duration of the removable light source.

The feasibility of this system is no longer in question. The smart scope has been used in various specialties: gynecology, urology, gastrology, otorhinolaryngology, etc.

In gynecology, a Greek team was able to create and test this device and proved its effectiveness in various surgical procedures. Thus it was possible to operate on ruptured ectopic pregnancies with hemoperitoneum, adnexal torsion, tubo-ovarian abscesses. This device has also made it possible to carry out diagnostic laparoscopy of ovarian cancer, enabling the extension and condition of the abdominal cavity to be assessed and biopsies of the mass to be performed. Image quality, resolution and acquisition were excellent, and the surgeons who performed the procedures reported no diagnostic problems with the new system [55].

Extrapolating the same principle, other basic surgeries such as appendectomy or cholecystectomy could be carried out without the need for a costly laparoscopic column.

In otolaryngology a Smartphone-based endoscopic device has also proven its clinical value and performance: The Smartphone system has shown an acceptable level of clarity for an ENT specialist to distinguish between healthy and diseased or damaged tissue regions via the Smartphone screen. By connecting to a wireless headset, the Smartphone-based endoscope system could even superimpose an endoscopic image on a real-world view [56].

In urology, a Smartphone coupled with a rigid endoscope can replace a cystoscope. It can be used in the emergency department for diagnostic procedures. As the system is fully self-contained and portable, it will make old, cumbersome and time-consuming procedures more efficient and cost-effective.

The 1951 USAF resolution test pattern was used to evaluate the image obtained from the smartscope. The results were found to be comparable to conventional cystoscopy for the rigid cystoscope [57].

The cost is approximately 50 to 70 times less than that of a standard high definition endoscopic camera [58]. Other devices replacing the usual laparoscopic surgical equipment have been developed and are constantly being improved. Optimization and validation of these systems is needed in terms of safety, as most of these devices are still in the experimental stage, but they have already proven to be of enormous benefit in developing countries: they are inexpensive and very easily reproducible. These devices have already been tested in basic laparoscopic surgeries: cholecystectomy, appendectomy, tubal ligation… [59].

The main advantages of the smart scope are:

• Cost: it costs 70 times less than the standard HD endoscopic camera [58].

The endoscope system with LED light source costs around \$45 with the cost of a Smartphone with a good camera estimated at \$1000 versus conventional video endoscopy with a standard camera and XL light source which costs \$45000 [60].

Ease of use and availability:


The only disadvantage of the smartscope is the limited duration of the removable light source.
