Echographic examination in isolated sites controlled from an expert center using a 2-D echograph guided by a teleoperated robotic arm.

The objective of the present project was to design and validate a method for teleoperating (from an expert site) an echographic examination in an isolated site. A dedicated robotic arm holding a real ultrasound (US) probe is remotely controlled from the expert site with a fictive probe, and reproduces on the real probe all the movements of the expert hand. The isolated places, defined as areas with reduced medical facilities, could be secondary hospitals 20 to 50 km from the university hospital, or dispensaries in Africa or Amazonia, or a moving structure like a rescue vehicle or the International Space Station (ISS). These sites are linked to the expert one by ISDN (numeric) telephone or satellite lines. At the expert center, the US medical expert moves a fictive probe, connected to a computer (no. 1) that sends the coordinate changes of this probe via an ISDN or satellite line to a second computer (no. 2), located at the isolated site, that applies them to the robotic arm holding the real echographic probe. The system was tested on 20 patients. In all cases, the expert was able to perform the main views (longitudinal, transverse) of the liver, gallbladder, kidneys, aorta, pancreas, bladder, prostate and uterus as during direct examination on the patient. The heart and spleen were not visualized in 2 and 4 of the 20 cases, respectively. The mean duration of the robotized echography (27 +/- 7 min for three to four organs) was approximately 50% longer than direct echography of the patient.