**6. The smartphone in the operating theater**

#### **6.1 Estimation of blood loss in the operating room**

Accurate assessment of blood loss is an important aspect of surgical management. Blood loss is usually assessed by visual estimation of the amount of blood in suction cartridges, surgical sponges and surgical drapes, which makes it very subjective.

An application has been recently developed to make this assessment more objective. It uses the Smartphone camera to capture images of surgical fields and then uses image analysis algorithms and cloud-based machine learning to accurately estimate the amount of hemoglobin (Hb) blood loss in real time on soaked surgical fields [51].

Another more relevant application developed by the same author allows the assessment of blood loss by estimating the hemoglobin level [52].

#### **6.2 Location of tumor lesions**

#### *6.2.1 In neurosurgery*

Operating theaters are equipped with microscopes to provide a good standard of care. However, in developing countries, microscopes are not always available. An adaptation of the Smartphone camera has been used as a valid alternative to the microscope. In a hospital in West Africa: using a simple tin can, a Smartphone shell and a rod attached to the bed, a Smartphone holder was created. This device provided surgeons with a magnification tool and a source of light in the surgical field. This simple "Smartphone-based exoscopy" allowed surgeons to obtain

adequate magnification during brain surgery. This device has made it possible to overcome the lack of microscopes or surgical magnifying glasses, and can be useful in countries with limited resources [53].
