Biomedical Engineering Reference
In-Depth Information
1.2 Conventional and Modern Surgical Techniques
Surgery is the treatment of diseases or other ailments through manual intervention using
instruments that cut and sew body tissues. In open surgery, referred to as the first-
generation technique, a large incision was usually made in the body that allowed the
surgeon full access to organs and tissues. Although this type of procedure allowed the
surgeon to have a wide range of motion, as well as tissue assessment through palpation,
the resulting trauma highlighted the limitations of this technique [5]. For instance, in a
conventional open-heart cardiac operation, or a cholecystectomy (gall bladder removal
surgery), the majority of trauma to the patient is caused by the surgeon's incisions to gain
access to the surgical site, rather than the procedure itself. The invasiveness of cracking
and splitting the rib cage to uncover the heart muscle, and trauma caused by incisions in
the abdomen to gain access to the gall bladder, causes a long postoperative hospital stay
and increasing cost and pain to the patient [6].
However, recent advances in surgery have greatly reduced the invasiveness of previous
surgical procedures and, to overcome many of the shortcomings and complications of
open surgery, MIS (referred to as the second-generation surgical procedure) was intro-
duced. It involves making very small incisions (referred to as access holes or trocar ports)
in the body through which very slender devices are inserted. These can be a laparoscopic
tool, an endoscope to allow the surgeon full view of the surgical site or a sharp pointed
instrument (trocar) enclosed in a metal tube (cannula) either to draw off fluid or to intro-
duce medication. Various other surgical instruments, such as clippers, scissors, graspers,
shears, cauterizers, dissectors, and irrigators are also used. These are mounted on long
poles and can be inserted and removed from the other trocar ports to allow the surgeon
to perform other necessary tasks. Upon completion of the surgical procedure, the trocars
are removed and the incisions closed.
There are, however, certain disadvantages with MIS. Because these procedures are
viewed on a 2D screen, the natural hand - eye coordination is disrupted, as indeed is
the surgeon's perception of depth [7]. Furthermore, because images from the camera are
magnified, small motions such as tremors in the camera, or even a heartbeat, can cause the
surgical team to experience motion-induced nausea. In addition, because there is no tactile
feedback, the surgeon has no sense of how hard he is pulling, cutting, twisting, or suturing.
There is a phenomenon referred to as SAID (specific adaption to imposed demands),
which can loosely be interpreted as meaning that your body always adapts to exactly
what you are doing, whether you are conscious of it or not. In terms of MIS, this means
that the surgeon is required to undergo a rigorous retraining program, otherwise he/she
is limited to performing either restricted or simpler surgical procedures. Because modern
surgical procedures are far more complex than in the past, and the surgeon's knowledge
and skill alone may not guarantee the success of an operation [8], a third-generation
of surgical procedures, robotic surgery, was developed to rectify this potential problem
since it places less stress on the surgeon and decreases both the surgical time and the
patient recovery period [9, 10]. However, the current medical robots have not eliminated
all the above-mentioned shortcomings. As an example, although the Da Vinci
and Zeus
medical robots have rectified a number of them, surgeons are still handicapped by the
lack of tactile sensing and its associated benefits [11, 12].
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