Sofar (Italy)

Topical studies [1-5] demonstrate that signal acquisition can be performed at sampling frequencies far below the minimal frequency dictated by the ideal sampling theorem, a concept called "compressive sampling" (CS). This technique can be applied to signals that don't convey the entire information amount predicted by the traditional sampling theory, regardless of the maximum frequency contained in their spectrum. Signals with this intriguing characteristic are called sparse.

To the editor: With great interest we read the article Total laparoscopic hysterectomy versus da Vinci robotic hysterectomy: is using the robot beneficial? by Soto et al. [1], which was published in your journal. The introduction of any new surgical system is expected to provide added value for existing ones, and we absolutely accept the conclusion of this excellent article that with experience a totally endoscopic hysterectomy still is superior to robotic surgery. Despite extensive work, telesurgery is probably still in its infancy. In our opinion, the main reason for the long operative time is the lack of haptic sensation and the reliance on visual force feedback. There have been claims that the results of visual force feedback and haptic feedback are comparable [2]. In a novel European telesurgical system, the Telelap Alf-x, the lack of tactile feedback has been overcome, and the surgeon can accurately feel the tensility of the knots she/he ties, which makes the telesurgical endoscopic procedure as similar as possible to open surgery. In experimental surgeries that were performed to find out whether haptic sensation will influence the operation time, the average time for cholecystectomy using the Telelap Alf-x was 31.75 minutes as compared to 91 minutes using a conventional telesurgical system [3]. Haptic sensation probably contributed to the self-confidence of the surgeon, who was not dependent on visual force feedback only. The Telelap Alf-x system is composed of 1 or 2 consoles and 3 or 4 long arms which enable abdominal or transdouglas access and to move freely around the patient during the surgery. The console supplies open 3D sight and is equipped with an eye-tracking system which moves any point that is looked at to the centre of the screen and instruments are activated by looking at the respective icon. The system stops movement when the surgeon's eyes are not fixed at the screen. All instruments are quickly attached to the arms by magnets and detect the pivot point on the fascia automatically to avoid extension of the incision. The instruments are reusable, and 1:1 haptic feedback is transmitted from the tip of the instrument to the surgeon's fingers when pushing or pulling, enabling to feel tissue consistency and the tension when knotting sutures. Despite the promising data resulting from our preliminary studies, we insist that telesurgery should have defined indications and should not be used unless prospective comparative studies have proven its superiority over conventional endoscopy.