4.3. Tool handle design
When designing a surgical instrument, certain criteria must be
fulfilled. Surgical instrument should be designed in a manner that
allows ease and universality of use, durability, mass production, fast
and easy sterilization, and resistance to physical and chemical agents.
All surgical tools can be classified into four categories: cutting and
dissecting instruments; grasping instruments; retracting instruments,
and wound closing instruments and materials.51
Surgical instruments are becoming more and more complex. Therefore,
designers face a challenging task to incorporate new features and
achieve better performance and optimal design.52
Traditional design techniques, which are geared toward user
characteristics, such as anthropometric design, do not contain
sufficient data for good instrument design to best adapt to target
population needs.
Minimally invasive surgical approaches significantly improve surgical
results. The instrumentation has changed significantly from open to
laparoscopic and robotic surgery with varying usability and ergonomic
qualities.53 In order to establish guidelines for the
future design of surgical instruments, it is necessary to assess the
effects of current surgical approaches and surgical instruments.
Laparoscopic surgery techniques have been shown to provide major
benefits to patients. However, surgeons are subjected to hard working
conditions due to poor ergonomic design of instruments. A review of
laparoscopic instruments reveals important design
aspects.54 It is concluded that there is a need for
more information on ergonomic guidelines on users’ sensory requirements
during design and production of surgical instruments.
Although robotic surgery seems to remove physical discomfort during and
after surgery, the results of different studies show that there is room
for improvement of seating positions and control lever ergonomics. It is
found that comfort and precision are the most important aspects of
surgical instrument selection.53
Although the benefits of minimally invasive surgery (MIS) are
undeniable, the surgeon must deal with disadvantages caused by
non-regional instrument handles. Inadequate ergonomic positioning of
arms and fingers can lead to pressure, nerve irritation, and rapid
fatigue. Therefore, it is necessary to compare ergonomic efficiency of
several different instruments’ handles used during surgery to find the
most adequate solution for surgery. It should be investigated whether
the position of the surgeon in relation to the patient during operation
affects the use of instrument handles. Recent studies show that the
shape of most used instrument handles causes users’ inconvenience and
that none of currently available handles on the market meet all
ergonomic criteria. The correct solution to this problem reflects the
need to embrace ergonomic recommendations when designing handles for MIS
instruments. It is necessary to use anatomical, physiological, and
ergonomic data, as well as the results of authentic experience. On this
basis, an ideal ergonomic working position for surgeons can be
recommended, with optimal understanding for manipulation of instrument’s
functional elements. In order to allow the surgeon to evaluate ergonomic
handles for MIS instruments according to their own needs, criteria for
actual „ergonomic handles“ must be introduced.55
Using ergonomic principles, providing both more intuitive instrument
manipulation and a form that reduces high-pressure zones in contact with
the arm of a surgeon, a new ergonomic handle design can be
proposed.51 New solutions selected in this manner not
only provide important ergonomic advantages, but also improve efficiency
when performing tasks by reducing extreme joint movements.