A Dual-Function Wheeled Probe for Tissue Viscoelastic Property Identification during Minimally Invasive Surgery

Abstract

This paper proposes a novel approach for the identification of tissue properties in-vivo using a force sensitive wheeled probe. The purpose of such a device is to compensate a surgeon for a portion of the loss of haptic and tactile feedback experienced during robotic-assisted minimally invasive surgery. Initially, a testing facility for validating the concept exvivo was developed and used to characterize two different testing modalities -static (1-DOF) tissue indentation and rolling (2-DOF) tissue indentation. As part of the static indentation experiments a mathematical model was developed to classify tissue condition based on changes in mechanical response. The purpose of the rolling indentation tests was to detect tissue abnormalities, such as tumors, which are difficult to isolate under static testing conditions. During such tests, the test-rig was capable of detecting simulated miniature buried masses at depths of 12mm. Based on these experiments a portable device capable of carrying out similar tests in-vivo was developed. The device was designed to be operated through a trocar port and its key feature is the ability to transition between static indentation and rolling indentation modalities without retracting and changing the tool.

Novel miniature MRI-compatible fiber-optic force sensor for cardiac catheterization procedures

“…These sensors were used for different kinds of measurements, such as blood pressure, oxygen level, blood flow, blood velocity and others. They make use of several sensing principles, such as strain-gauges [8], piezoresistivity [9], PVDF films [1] and fibre-optic technology [10], [11], [15]. However, only a small number of sensors were developed for the detection of contact forces between the catheter and tissue [12], [13].…”

Technological assessment of the biogalvanic method for tissue characterization

“…Sensing modalities look to exploit various underlying properties that pertain to tissue health. Alteration of tissue mechanical properties with pathology has been assessed intraoperatively through direct mechanical contact measurement (Zbyszewski et al, 2009, Noonan et al, 2007 and ultrasound based elastography techniques (Gao et al, 1996, Elias et al, 2011. Palmeri and Nightingale (2011) discuss some of the issues associated with elastography, with the challenges of applying repeatable physical stimulation and quantitatively interpreting data through a suitable mathematical model being shared throughout mechanical characterisation modalities.…”

Pseudo-haptics for rigid tool/soft surface interaction feedback in virtual environments

“…The soft object stiffness 3D haptic data which is used for the purposes of this paper comes from the rolling/sliding indentation method introduced by [6], [23]- [25] to detect tissue abnormalities.…”

“…All of the nodules were buried at a depth of 6 mm; this distance was measured from the top of the each nodule to the silicone surface. To obtain a rolling/sliding stiffness map [6], [23]- [25], 59 straight-line trajectories (121 mm long and parallel to the x-axis with a interval of 4 mm between trajectories along the y-axis) were defined. A robot arm (Mitsubishi RV-6SL 6-DOFrobotic manipulator with a positioning accuracy of 0.01 mm) was programmed to move attached the rolling indentation probe along these 59 straight-line trajectories at a speed of 30 mm/s with a constant rolling indentation depth.…”