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Micro-drilling in Surgery

This research is producing a series of micro-drilling devices. The key is to register the tool point position with respect to tissue position automatically in real-time. Often there is a need to identify tissue types and behaviour, and to control the tool-point with respect to the detected tissue interfaces and membranes. The robotic surgical micro-drill produced is able to discriminate these conditions as different states in a process and moves the tool point autonomously to achieve consistent and precise results.

Micro-drill

The system has been used successfully in the operating theatre  and has achieved precise cochleostomies. Use of this tool has  shown that precise and consistent results can be achieved  efficiently. When drilling a cochleostomy the medial interface of the bone structure of the cochlea is discriminated against the delicate endosteal membrane in real-time such that the device penetrates the bone tissue without penetrating the membrane. As a result, trauma to the hearing organ is reduced, there is greater opportunity to retain residual hearing, sterility is maintained and debris can be removed before insertion of the electrode. These factors are expected to reduce the incidence of complications and are of growing importance as cochleostomies are becoming more common in patients with lower degrees of hearing loss.

This approach to drilling has many applications in surgery.

In More Detail...

The micro-drilling system consists of:

  • Drill unit comprising of precision actuators and sensing elements
  • Flex and lock arm
  • Hardwired control unit
  • A laptop computer

Micro-drill details

Control is via hardware. The laptop relays information on the state of the tool-point/tissue interaction. The hand held remote unit enables supervisory control. Force and torque transients at the tool-point are interpreted automatically in real time. The relationship between transients are used to discriminate between different states in the process and these can be the condition of the tool and tissue, patient and tool movement, approach towards tissue boundaries and drill breakthrough. With this information it is possible to interpret the critical breakthrough event before it occurs and to automatically control drill penetration precisely with respect to this deformingtissue boundary.