Tele-surgery is one of the emerging fields which combine engineering and medical sciences.
Application of tole-surgery can be found in remote communities, war-zones and disasterstricken
areas. One of the most complex and tedious issue in tele-surgery is needle insertion.
The surgeon relies on haptic feedback during needle insertion. The force exerted on needle
during insertion is measured and reproduced at surgeon's end is known as haptic feedback.
The realistic force reproduction requires haptic feedback device which should be
dynamically identical to needle. The haptic feedback device enables the surgeon to sense the
needle insertion remotely.
The basic objective of this thesis is to design a device used for needle insertions in soft tissue.
The force information from needle insertions is measured by a sensor. The force feedback
produced by the device can be used in robot-assisted needle insertion. A device is designed
for reality-based data that results in more accurate representation of a needle insertion haptic
feedback scenario.
The device is modeled dynamically and it is clear from the model that the reactive force is
reproduced by the friction forces which is controlled by the motors. The system is sensitive
to mass of rollers, mass of the stick and friction between the stick and rollers.
The needle insertion force is modeled in three parts; force due to capsule stiffness, friction,
and cutting. The force due to capsule stiffness is modeled terms of three components namely
diameter of needle, elasticity of tissue and deformation of tissue. The data from model is
compared with real time force data. The haptic feedback device input and output forces are
compared and the highest correlation factor is 82%. The sensitivity analysis of the device is
performed. The capsule stiffness force for 0.9 millimeter diameter needle is 0.98 Newton, the
stiffness force for 0.8 millimeter is 0.91 Newton and stiffness force for 0.6 millimeter
diameter is 0.41 Newton. The capsule stiffness force for 0.6 millimeter needle is not
following the capsule stiffness model. The insertion force data was collected on chicken skin
and meat.
The device designed in this work is having one degree of freedom; it only produces force
feedback for vertical needle insertion. This design is not able to produce the force feedback
for angular needle insertion.
Graphical User Interface is designed for the visual haptic feedback. The data acquisition is
done with the help of a PC sound card. Future work should include the design of a multidegree
of freedom haptic feedback device and to advance the GUI for audio feedback that
may be extended to accommodate the design of a simulator
