As modern medical advances allow increasingly
accurate diagnoses, there is a clear expectation among the public
that surgical intervention can be carried out with comparable speed
and precision. But as such treatments increase in complexity, the
skills required to carry them out become ever more rare and costly.
Often, for example, there is a need to work through deep and narrow
access points, where the surgeon is unable to sense the action at
the tip of the tool. Adjacent soft tissues can be easily damaged,
even by the most skilled of human hands. Mechatronic technologies
can be applied in a broad range of medical and surgical applications,
reducing the level of skills required and the costs incurred.
The term mechatronics refers to systems for sensing and controlling
the movement and deformation of materials under forces applied by
automatic surgical tools. When dealing with soft tissues, changes
in tool action need to respond to tissue movement. In this project,
sensing schemes to infer tissue behaviour and to automatically achieve
precise tool action with respect to deforming tissues were developed
for tools working in different tissue types. Intelligent software
analyses the changes in sensory data and makes microfine adjustments
in tool operations.
Techniques under the microscope
This project's goal was to advance the use of
mechatronics in very difficult surgical procedures. From the outset,
four separate surgical applications were targeted, all representing
concrete opportunities for commercial exploitation.
First, a new system for mechatronic stapedotomy was developed. Stapedotomy
involves drilling a hole through one of the small bones in the inner
ear. The new, automatic breakthrough detection system stops the
drill as soon as the bit has broken through the bone, thus avoiding
damage to sensitive tissues on the other side. Until now, the low
drilling forces used have made this a delicate operation with high
risk of accidental damage.
Secondly, an improved epidural puncture procedure was developed,
including a force simulator for surgeon training. Penetrating spinal
tissue to inject pain-relieving fluids is a procedure widely used
in surgery but one which carries a risk of spinal damage or ineffectual
injection if the needle is positioned inaccurately.
New methods were developed for drilling in the osteosynthesis of
long bones, very similar to the stapedotomy procedure described
above. Finally, improved laser ablation techniques were designed
for the removal of deep-seated brain tumours. New software helps
to guide the ablation probe, avoiding blood vessels which must not
be damaged, and removes the need for intervention by a specialist
Sensors and software
All the new systems involve the introduction
of novel sensors and software to provide safer, more reliable operations
where previously skilled and experienced surgeons were required.
Particular innovation was displayed in the application of software
and sensor techniques to improving positional accuracy and force
feedback. Each new technique has the potential to improve patient
recovery times and to reduce the incidence of cross infection between
surgeon and patient, thanks to their limited invasiveness.
These and other developments could make certain delicate surgical
operations more widely available by enabling less-experienced surgeons
to perform the work without any increase in risks. Shorter recovery
times, lowered risk of infection and greater availability of operations
will also contribute substantially to lower costs for health service
Remote control comes closer
Although it was not a declared goal of
the project, the new technology could ultimately contribute to groundbreaking
developments in telemedicine. The ability of expert surgeons to
manage operations remotely currently relies on local surgeons working
to expert's instructions via audio and video links. The sensors
developed under this project can now provide surgeons with live
feedback, enabling them to actually conduct some operations remotely
themselves. This opens up the possibility of bringing specialist
surgery to patients unable to travel to conventional hospitals,
for example after major disasters.
Project partners included the Universities of Bristol, Siegen and
Thessaloniki and the Scuola Superiore Santa Anna in Italy, four
distinguished research institutions well known to each other through
academic networks, demonstrating that original, focused applied
research can be successfully concluded without the support of industrial