Page 166 - Flexible Robotics in Medicine

152 Chapter 6

corneal procedures, but with the added complication of obstructed vision, which makes
proper illumination a key priority [11].

6.1.2 Robotic ocular surgery

Surgery has long been an area of the large potential for robotics, and with the technological
advancements that have been made in recent years, robotic surgery has become a distinct
reality. Robot-assisted surgical methods have helped to overcome problems in manual
surgery, such as hand tremors [12], while complete surgical systems, such as the da Vinci
surgical system, have revolutionized entire surgical fields by significantly increasing the
range of motion and vision of surgeons in laparoscopy [13].

The adoption of robotics in ophthalmic surgery has not been as significant [14], primarily
due to the fact that the field does not suffer from the restricted range of motion or awkward
and uncomfortable operating positions that make robotic surgery so attractive to
laparoscopy. However, as ophthalmic surgeries are usually performed through a microscope
and need precise manipulations using delicate instruments, robotic surgery can be used to
address issues pertinent to eye surgery, such as hand tremors and lack of precision and
accuracy. Solving these problems could potentially allow for procedures that are not so
common at present, such as intravascular drug delivery [15].
As a result, research in robotics for eye surgery has shifted from single-task robots, which
tried to maintain the remote center of motion (RCM) and the 6-degrees-of-freedom (DOF)
robot capable of performing retinal cannulation, to entire surgical systems. Multiple
feasibility studies [16,17] have been conducted to test the usefulness of currently available
surgical systems in ophthalmic surgery. Of particular note is the da Vinci surgical system,
which is the commercially dominating robotic surgical system available today. Early studies
[16,17] showed that while the da Vinci was able to provide excellent control of tools and
had the necessary dexterity required to perform ophthalmic surgical tasks such as suturing
of corneal lacerations, 25-gauge par plana vitrectomy, and anterior capsulorhexis. The
studies further brought up several issues with the da Vinci, such as its high-setup cost,
absent retro-illumination, obstructed maneuverability of the instruments due to endoscope
position, having to reposition the endoscope multiple times, and an RCM that was not at the
level of the eye, which caused unwanted lateral tension on the eye surface.

Since those first studies, published in 2008, devices have been proposed to better adapt the
da Vinci platform to ophthalmic surgery, such as the hexapod surgical system [18], which
was designed to be attached to the da Vinci and would allow for an RCM at the site of
ocular penetration, or “The Microhand” [19]; a novel micro-forceps concept made using
MEMS that mimics the human hand. Other investigators, such as the team behind IRISS
[20], have taken a different approach and designed a surgical platform for ocular surgery