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Feasibility study of a hand guided robotic drill for cochleostomy.

Brett P, Du X, Zoka-Assadi M, Coulson C, Reid A, Proops D - Biomed Res Int (2014)

Bottom Line: The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator.The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory.This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced.

View Article: PubMed Central - PubMed

Affiliation: Brunel Institute for Bioengineering, Brunel University, London UB8 3PH, UK.

ABSTRACT
The concept of a hand guided robotic drill has been inspired by an automated, arm supported robotic drill recently applied in clinical practice to produce cochleostomies without penetrating the endosteum ready for inserting cochlear electrodes. The smart tactile sensing scheme within the drill enables precise control of the state of interaction between tissues and tools in real-time. This paper reports development studies of the hand guided robotic drill where the same consistent outcomes, augmentation of surgeon control and skill, and similar reduction of induced disturbances on the hearing organ are achieved. The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator. The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory. This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced. The results for trials on phantoms show that drill unit compliance is an important factor in the design.

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Simulated coupled drilling feed force and torque (assuming drilling through in cochleostomy) showing principal characteristics [12].
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fig2: Simulated coupled drilling feed force and torque (assuming drilling through in cochleostomy) showing principal characteristics [12].

Mentions: The mathematical model, reported in [12], predicts results shown in Figure 2 that help to describe typical features used by the tactile sensing scheme to identify the approach to a tissue interface such that penetration can be avoided. The drill bit feed force and torque are plotted as functions of displacement. The characteristics indicate clear changes in transients between coupled signals that correspond to stages in the process. In this simulation feed rate is assumed to be constant. The force and torque transients clearly show the point at which hole depth is equal to the burrs radius at stage 2 at approximately 0.5 mm and is indicated by an observable change in gradient of the torque transient. Onset of breakthrough occurs at stage 3 at approximately 1.3 mm resulting in the sharp increase and subsequent roll-off in the force signal. Amongst other properties and tissue behaviour, these coupled features of the sensory transients are used to anticipate the position of the tissue interface precisely. If drilling did not cease at this point then the hole would be completed at stage 4, at approximately 1.4 mm. The force and torque would then fall to zero when full penetration occurred. If penetration is allowed to take place, then in reality the tip of the drill bit will have penetrated much further beyond the tissue interface than is necessary to complete the removal of bone tissue of the cochlea as the tissues are flexible and will have deflected significantly in response to tool forces prior to penetration. Avoiding penetration is important in the process to minimise trauma of the hearing organ, as is the amplitude of disturbances induced during the drilling process [13].


Feasibility study of a hand guided robotic drill for cochleostomy.

Brett P, Du X, Zoka-Assadi M, Coulson C, Reid A, Proops D - Biomed Res Int (2014)

Simulated coupled drilling feed force and torque (assuming drilling through in cochleostomy) showing principal characteristics [12].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109386&req=5

fig2: Simulated coupled drilling feed force and torque (assuming drilling through in cochleostomy) showing principal characteristics [12].
Mentions: The mathematical model, reported in [12], predicts results shown in Figure 2 that help to describe typical features used by the tactile sensing scheme to identify the approach to a tissue interface such that penetration can be avoided. The drill bit feed force and torque are plotted as functions of displacement. The characteristics indicate clear changes in transients between coupled signals that correspond to stages in the process. In this simulation feed rate is assumed to be constant. The force and torque transients clearly show the point at which hole depth is equal to the burrs radius at stage 2 at approximately 0.5 mm and is indicated by an observable change in gradient of the torque transient. Onset of breakthrough occurs at stage 3 at approximately 1.3 mm resulting in the sharp increase and subsequent roll-off in the force signal. Amongst other properties and tissue behaviour, these coupled features of the sensory transients are used to anticipate the position of the tissue interface precisely. If drilling did not cease at this point then the hole would be completed at stage 4, at approximately 1.4 mm. The force and torque would then fall to zero when full penetration occurred. If penetration is allowed to take place, then in reality the tip of the drill bit will have penetrated much further beyond the tissue interface than is necessary to complete the removal of bone tissue of the cochlea as the tissues are flexible and will have deflected significantly in response to tool forces prior to penetration. Avoiding penetration is important in the process to minimise trauma of the hearing organ, as is the amplitude of disturbances induced during the drilling process [13].

Bottom Line: The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator.The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory.This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced.

View Article: PubMed Central - PubMed

Affiliation: Brunel Institute for Bioengineering, Brunel University, London UB8 3PH, UK.

ABSTRACT
The concept of a hand guided robotic drill has been inspired by an automated, arm supported robotic drill recently applied in clinical practice to produce cochleostomies without penetrating the endosteum ready for inserting cochlear electrodes. The smart tactile sensing scheme within the drill enables precise control of the state of interaction between tissues and tools in real-time. This paper reports development studies of the hand guided robotic drill where the same consistent outcomes, augmentation of surgeon control and skill, and similar reduction of induced disturbances on the hearing organ are achieved. The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator. The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory. This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced. The results for trials on phantoms show that drill unit compliance is an important factor in the design.

Show MeSH