Several surgical specialties have been rapidly transformed by minimally invasive surgery. A central example is laparoscopic cholecystectomy, or gallbladder excision, a common procedure that is executed almost exclusively using minimally invasive surgery techniques. Surgeons work through a set of three to five incisions approximately 1 cm in size. Long-handled instruments are used to grip and cut tissue within the body, and a video laparoscope provides a view of the internal operating field.
Because this procedure avoids the long incision through abdominal wall used in the conventional open procedure, patients recover more quickly. Benefits include greatly reduced discomfort, improved cosmesis, reduced convalescence and hospitalization costs, and less time away from productive work.
The necessity of working through a few fixed incisions places severe limitations on dexterity in manipulation, and only a few procedures are possible with the current hand-held instruments. Lateral movement of the instrument shaft is not possible at the incision, which thus act as a fulcrum, reversing the directions of the surgeon’s hand motions at the instrument tip and varying the mechanical advantage as the instruments move in and out. The video monitor is often located on the far side of the patient, and the difference in orientation between the endoscope and the monitor requires the surgeon to perform a difficult mental transformation between visual and motor coordinate frames. Contact force perception is impaired by friction and varying mechanical advantage at the incision, and distributed tactile information is absent.
No comments:
Post a Comment