Camera-Robot Calibration for the da Vinci® Robotic Surgery System.

The development of autonomous or semi-autonomous surgical robots stands to improve the performance of existing teleoperated equipment, but requires fine hand-eye calibration between the free-moving endoscopic camera and patient-side manipulator arms (PSMs). A novel method of solving this problem for the da Vinci® robotic surgical system and kinematically similar systems is presented. First, a series of image-processing and optical-tracking operations are performed to compute the coordinate transformation between the endoscopic camera view frame and an optical-tracking marker permanently affixed to the camera body.

Is the Vertical-Horizontal Illusion a Byproduct of the Environmental Vertical Illusion?

The vertical-horizontal illusion is the overestimation of a vertical line compared to a horizontal line of the same length. Jackson and Cormack (2007) proposed that the vertical-horizontal illusion might be a byproduct of the mechanisms that generate the environmental vertical illusion, which is the tendency to overestimate vertical distances (i.e.

State Estimation for MRI-Actuated Catheters via Catadioptric Stereo Camera.

An MRI-actuated catheter is a novel robotic catheter system that utilizes the MR scanner for both remote steering and catheter tracking. In order to develop the mathematical model and the planning algorithm of the catheter in parallel to the MR tracking system, an alternative catheter tracking method is needed. This paper presents a catheter tracking algorithm based on the particle filter and the catadioptric camera system.

Analysis of Dynamic Response of an MRI-Guided Magnetically-Actuated Steerable Catheter System.

This paper presents a free-space open-loop dynamic response analysis for an MRI-guided magnetically-actuated steerable intra-vascular catheter system. The catheter tip is embedded with a set of current carrying micro-coils. The catheter is directly actuated via the magnetic torques generated on these coils by the magnetic field of the magnetic resonance imaging (MRI) scanner.

Real-Time Visual Tracking of Dynamic Surgical Suture Threads.

In order to realize many of the potential benefits associated with robotically assisted minimally invasive surgery, the robot must be more than a remote controlled device. Currently, using a surgical robot can be challenging, fatiguing, and time consuming. Teaching the robot to actively assist surgical tasks, such as suturing, has the potential to vastly improve both patient outlook and the surgeon's efficiency.

Three-Dimensional Surgical Needle Localization and Tracking Using Stereo Endoscopic Image Streams.

This paper presents algorithms for three-dimensional tracking of surgical needles using the stereo endoscopic camera images obtained from the da Vinci Surgical Robotic System. The proposed method employs Bayesian state estimation, computer vision techniques, and robot kinematics. A virtual needle rendering procedure is implemented to create simulated images of the surgical needle under the da Vinci robot endoscope, which makes it possible to measure the similarity between the rendered needle image and the real needle.

Iterative Jacobian-Based Inverse Kinematics and Open-Loop Control of an MRI-Guided Magnetically Actuated Steerable Catheter System.

This paper presents an iterative Jacobian-based inverse kinematics method for an MRI-guided magnetically-actuated steerable intravascular catheter system. The catheter is directly actuated by magnetic torques generated on a set of current-carrying micro-coils embedded on the catheter tip, by the magnetic field of the magnetic resonance imaging (MRI) scanner. The Jacobian matrix relating changes of the currents through the coils to changes of the tip position is derived using a three dimensional kinematic model of the catheter deflection.

Experimental Validation of the Pseudo-Rigid-Body Model of the MRI-Actuated Catheter.

An MRI-actuated catheter is a novel robotic catheter system that utilizes the MRI for both remote steering and visualization for catheter ablation of atrial fibrillation. Planning and control of the catheter requires a sufficiently fast yet accurate model of the catheter. The pseudo-rigid-body (PRB) model offers a reasonable trade-off between speed and accuracy by approximating the continuum catheter as rigid links connected by flexible joints, thus reducing the infinite degrees of freedom of the continuum mechanism to a finite one.

PeakCaller: an automated graphical interface for the quantification of intracellular calcium obtained by high-content screening.

Background: Intracellular calcium is an important ion involved in the regulation and modulation of many neuronal functions. From regulating cell cycle and proliferation to initiating signaling cascades and regulating presynaptic neurotransmitter release, the concentration and timing of calcium activity governs the function and fate of neurons. Changes in calcium transients can be used in high-throughput screening applications as a basic measure of neuronal maturity, especially in developing or immature neuronal cultures derived from stem cells.

Catadioptric Stereo Tracking for Three Dimensional Shape Measurement of MRI Guided Catheters.

The recent introduction of Magnetic Resonance Imaging (MRI)-actuated steerable catheters lays the ground work for increasing the efficacy of cardiac catheter procedures. The MRI, while capable of imaging the catheter for tracking and control, does not fulfill all of the needs required to identify and develop a complete catheter model. Specifially, the frequency response of the catheter must be identified to ensure stable control of the catheter system.

Evolved navigation illusion provides universal human perception measure.

The ability to replicate an experiment across any scientific discipline rests on the assumption that different experimenters are capable of perceiving the same methods and outcomes. However, the large individual differences in experimenters' visual perception undermine this tenet of the scientific process. Further, common devices for measuring similarity in perceptual capacity do not replicate across human groups.

Needle-Tissue Interaction Force State Estimation for Robotic Surgical Suturing.

Robotically Assisted Minimally Invasive Surgery (RAMIS) offers many advantages over manual surgical techniques. Most of the limitations of RAMIS stem from its non-intuitive user interface and costs. One way to mitigate some of the limitations is to automate surgical subtasks (e.

Automatic Initialization and Dynamic Tracking of Surgical Suture Threads.

In order to realize many of the potential benefits associated with robotically assisted minimally invasive surgery, the robot must be more than a remote controlled device. Currently using a surgical robot can be challenging, fatiguing, and time consuming. Teaching the robot to actively assist surgical tasks, such as suturing, has the potential to vastly improve both patient outlook and the surgeon's efficiency.

Needle Path Planning for Autonomous Robotic Surgical Suturing.

This paper develops a path plan for suture needles used with solid tissue volumes in endoscopic surgery. The path trajectory is based on the best practices that are used by surgeons. The path attempts to minimize the interaction forces between the tissue and the needle.

Visual field dependence as a navigational strategy.

Visual perception is an important component of environmental navigation. Previous research has revealed large individual differences in navigational strategies (i.e.

Animacy, perceptual load, and inattentional blindness.

Inattentional blindness is the failure to notice unexpected objects in a visual scene while engaging in an attention-demanding task. We examined the effects of animacy and perceptual load on inattentional blindness. Participants searched for a category exemplar under low or high perceptual load.

Evolutionary relevance facilitates visual information processing.

Visual search of the environment is a fundamental human behavior that perceptual load affects powerfully. Previously investigated means for overcoming the inhibitions of high perceptual load, however, generalize poorly to real-world human behavior. We hypothesized that humans would process evolutionarily relevant stimuli more efficiently than evolutionarily novel stimuli, and evolutionary relevance would mitigate the repercussions of high perceptual load during visual search.

Context is quick, knowledge is slow: rapid time-course of contextual modulations in the horizontal-vertical illusion.

One of the oldest visual illusions consists of observers' tendency to estimate vertical lines as longer than equal horizontal lines. This Horizontal-Vertical Illusion has been studied widely; however, most studies may not generalize to natural contexts because they have not addressed the low-level processes that occur rapidly and in response to context-free lines vs the possibility for high-level processes that arise over time in response to context. These issues were investigated via a novel design: rapid time-sequencing embedded within the context of natural images.

Evolved navigation theory and the plateau illusion.

Most people anecdotally feel that the distance extending toward a cliff or slope appears shorter than the same distance extending away from it. This odd impression persists, despite the distance being equal across both conditions and humans encountering such a scenario daily in the navigation of stairs, slopes, curbs, and vertical surfaces protected by handrails. We tested three sets of competing predictions about this previously uninvestigated phenomenon.

Learning and exposure affect environmental perception less than evolutionary navigation costs.

Most behaviors are conditional upon successful navigation of the environment, which depends upon distance perception learned over repeated trials. Unfortunately, we understand little about how learning affects distance perception-especially in the most common human navigational scenario, that of adult navigation in familiar environments. Further, dominant theories predict mutually exclusive effects of learning on distance perception, especially when the risks or costs of navigation differ.

Preference for the nearer of otherwise equivalent navigational goals quantifies behavioral motivation and natural selection.

Navigation and environmental perception precede most actions in mobile organisms. Navigation is based upon the fundamental assumption of a ubiquitous Preference for the Nearest of otherwise equivalent navigational goals (PfN). However, the magnitude and triggers for PfN are unknown and there is no clear evidence that PfN exists.

Modeling of Needle-Tissue Interaction Forces During Surgical Suturing.

This paper presents a model of needle tissue interaction forces that a rigid suture needle experiences during surgical suturing. The needle-tissue interaction forces are modeled as the sum of lumped parameters. The model has three main components; friction, tissue compression, and cutting forces.

Estimation of Soft Tissue Mechanical Parameters from Robotic Manipulation Data.

Robotic motion planning algorithms used for task automation in robotic surgical systems rely on availability of accurate models of target soft tissue's deformation. Relying on generic tissue parameters in constructing the tissue deformation models is problematic; because, biological tissues are known to have very large (inter- and intra-subject) variability. A priori mechanical characterization (e.

Evolved navigation theory and horizontal visual illusions.

Environmental perception is prerequisite to most vertebrate behavior and its modern investigation initiated the founding of experimental psychology. Navigation costs may affect environmental perception, such as overestimating distances while encumbered (Solomon, 1949). However, little is known about how this occurs in real-world navigation or how it may have evolved.

Reducing the presence of navigation risk eliminates strong environmental illusions.

Many researchers have assumed that navigational costs, as opposed to the visual stimuli per se, produce several large-magnitude distance illusions-in spite of the absence of experimental data. We used virtual reality to remove the presence of realistic falling costs, while leaving the visual information otherwise intact. This resulted in removal of the distance illusions proposed to have evolved in response to falling costs.