David P. Noonan

An articulated universal joint based flexible access robot for minimally invasive surgery

This paper introduces an articulated robotic device based on universal joints with embedded micro motors for minimally invasive surgery. The device features an articulated distal tip with seven independently controllable degrees-of-freedom (DoF), arranged as two universal joints (intersecting pitch and yaw) and three single DoF joints (yaw only); two Ø3mm internal channels, one for an on-board camera for visualization and the other for passing interventional instruments. The design allows the robot to explore the entire peritoneal cavity from a chosen single incision point. A trans-vaginal procedure using the device to locate the uterine horn, as a model of a human fallopian tube, and apply an endoscopic clip was carried out during a live porcine trial to demonstrate the potential for performing a Natural Orifice Translumenal Endoscopic Surgery (NOTES) tubal ligation procedure.

Rolling Mechanical Imaging for Tissue Abnormality Localization During Minimally Invasive Surgery

We describe a novel approach for the localization of tissue abnormalities during minimally invasive surgery using a force-sensitive wheeled probe. The concept is to fuse the kinaesthetic information from the wheel-tissue rolling interaction into a pseudocolor rolling mechanical image (RMI) to visualize the spatial variation of stiffness within the internal tissue structure. Since tissue abnormalities are often firmer than the surrounding organ or parenchyma, a surgeon then can localize abnormalities by analyzing the image. Initially, a testing facility for validating the concept in an ex vivo setting was developed and used to investigate rolling ¿wheel-tissue¿ interaction. A silicone soft-tissue phantom with embedded hard nodules was constructed to allow for experimental comparison between an RMI and a known soft-tissue structure. Tests have also been performed on excised porcine organs to show the efficacy of the method when applied to biological soft tissues. Results indicate that the RMI technique is particularly suited to identifying the stiffness distribution within a tissue sample, as the continuous force measurement along a given rolling trajectory provides repeatable information regarding relative variations in the normal tissue response. When compared to multiple discrete uniaxial indentations, the continuous measurement approach of RMI is shown to be more sensitive and facilitates coverage of a large area in a short period of time. Furthermore, if parametric classification of tissue properties based on a uniaxial tissue indentation model is desirable, the rolling indentation probe can be easily employed as a uniaxial indenter.

Design of a multitasking robotic platform with flexible arms and articulated head for Minimally Invasive Surgery

This paper describes a multitasking robotic platform for Minimally Invasive Surgery (MIS). The device is designed to be introduced through a standard trocar port. Once the device is inserted to the desired surgical site, it can be reconfigured by lifting an articulated section, and protruding two tendon driven flexible arms. Each of the arms holds an interchangeable surgical instrument. The articulated section features a 2 Degrees-of-Freedom (DoF) universal joint followed by a single DoF yaw joint. It incorporates an on-board camera and LED light source at the distal end, leaving a Ø3mm channel for an additional instrument. The main shaft of the robot is largely hollow, leaving ample space for the insertion of two tendon driven flexible arms integrated with surgical instruments. The ex-vivo and in-vivo experiments demonstrate the potential clinical value of the device for performing surgical tasks through single incision or natural orifice transluminal procedures.

A Hand-held Instrument to Maintain Steady Tissue Contact during Probe-Based Confocal Laser Endomicroscopy

Probe-based confocal laser endomicroscopy (pCLE) provides high-resolution in vivo imaging for intraoperative tissue characterization. Maintaining a desired contact force between target tissue and the pCLE probe is important for image consistency, allowing large area surveillance to be performed. A hand-held instrument that can provide a predetermined contact force to obtain consistent images has been developed. The main components of the instrument include a linear voice coil actuator, a donut load-cell, and a pCLE probe. In this paper, detailed mechanical design of the instrument is presented and system level modeling of closed-loop force control of the actuator is provided. The performance of the instrument has been evaluated in bench tests as well as in hand-held experiments. Results demonstrate that the instrument ensures a consistent predetermined contact force between pCLE probe tip and tissue. Furthermore, it compensates for both simulated physiological movement of the tissue and involuntary movements of the operators hand. Using pCLE video feature tracking of large colonic crypts within the mucosal surface, the steadiness of the tissue images obtained using the instrument force control is demonstrated by confirming minimal crypt translation.

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

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 ex-vivo 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.

Gaze contingent articulated robot control for robot assisted minimally invasive surgery

This paper introduces a novel technique for controlling an articulated robotic device through the eyes of the surgeon during minimally invasive surgery. The system consists of a binocular eye-tracking unit and a robotic instrument featuring a long, rigid shaft with an articulated distal tip for minimally invasive interventions. They have been integrated into a daVinci surgical robot to provide a seamless and non-invasive localization of eye fixations of the surgeon. By using a gaze contingent framework, the surgeonpsilas fixations in 3D are converted into commands that direct the robotic probe to the desired location. Experimental results illustrate the ability of the system to perform real-time gaze contingent robot control and opens up a new avenue for improving current human-robot interfaces.

A stereoscopic fibroscope for camera motion and 3D depth recovery during Minimally Invasive Surgery

This paper introduces a stereoscopic fibroscope imaging system for Minimally Invasive Surgery (MIS) and examines the feasibility of utilizing images transmitted from the distal fibroscope tip to a proximally mounted CCD camera to recover both camera motion and 3D scene information. Fibre image guides facilitate instrument miniaturization and have the advantage of being more easily integrated with articulated robotic instruments. In this paper, twin 10,000 pixel coherent fibre bundles (590µm diameter) have been integrated into a bespoke laparoscopic imaging instrument. Images captured by the system have been used to build a 3D map of the environment and reconstruct the laparoscopes 3D pose and motion using a SLAM algorithm. Detailed phantom validation of the system demonstrates its practical value and potential for flexible MIS instrument integration due to the small footprint and flexible nature of the fibre image guides.

The Natural Orifice Simulated Surgical Environment (NOSsE™): Exploring the Challenges of NOTES Without the Animal Model

In this paper, we introduce an inexpensive, realistic, and robust simulator model for training and requirement assessment of natural orifice transluminal endoscopic surgery (NOTES). A laparoscopic box trainer is converted into an effective NOTES environment, in which many of the challenges facing this new approach can be explored first hand in a laboratory setting. Using this simulator, experiments researching this new surgical field can be refined before moving into in vivo trials, such that the number of animals required for acquiring basic skills and validating new surgical protocols can be reduced. Additionally, the simulator has the potential to be utilized as an effective platform for education and training in NOTES, although formal validation is required before this can truly be appreciated.

Gaze contingent control for an articulated mechatronic laparoscope

This paper introduces two techniques for controlling an articulated mechatronic laparoscope through the eyes of the surgeon during minimally invasive surgery. The system consists of a 2D eye tracking unit interfaced with a mechatronic laparoscope that has five controllable degrees-of-freedom (DoF) located at the distal end of a rigid shaft. Through the use of image feedback from a tip mounted camera, a closed-loop gaze contingent framework featuring two separate control techniques (“Individual Joint Selection” and “Automatic Joint Selection”) was developed. Under this framework, the location of a surgeons 2D fixation point is converted into commands that servo the laparoscope. Experimental results illustrate the ability of both techniques to perform real-time gaze contingent laparoscope control. A key advantage of the proposed system is the ability to provide the operator with sufficient distal dexterity to achieve stable off-axis visualisation in an intuitive, hands-free manner, thus allowing other handheld instruments to be controlled simultaneously. Potential applications include Single Incision Laparoscopic Surgery (SILS) or Natural Orifice Trans-Endoluminal Surgery (NOTES), where the use of multiple instruments passing through a single incision presents both visualization and ergonomic challenges.

A Global Approach for Automatic Fibroscopic Video Mosaicing in Minimally Invasive Diagnosis

Recent developments in bio-photonics have called for the need of bringing cellular and molecular imaging modalities to an in vivo--in situ setting to allow for real-time tissue characterization and functional assessment. Before such techniques can be used effectively in routine clinical environments, it is necessary to address the visualization requirement for linking point based optical biopsy to large area tissue visualization. This paper presents a novel approach for fibered endoscopic video mosaicing that permits wide region tissue visualization. A feature-based registration method is used to register the frames of the endoscopic video sequence by taking into account the characteristics of fibroscopic imaging such as non-linear lens distortion and high-frequency fiber optic facet pattern. The registration is combined with an efficient optimization scheme in order to align all input frames in a globally consistent way. An evaluation on phantom and ex vivo tissue images allowing free-hand camera motion is presented.