An endoscopic solo surgery simulator was designed to quantitatively evaluate human-machine interface in robotic camera positioning systems. Our simulator can assess not only the quantitative efficiency of laparoscopic cameraworks but also the influence of cameraworks upon the accuracy of surgical actions. Two human-machine interfaces: a face motion navigation system and a voice activated system were developed and compared. As a result, the face control interface was more efficient in cameraworks than the voice control, even under a stress to control the instruments. However, it was also found that the face motion may have bad influence on precise surgical actions.

Medical Image Computing and Computer-Assisted Intervention — MICCAI 2002

Methods, apparatuses, and systems relating to image guided interventions on dynamic tissue. One embodiment is a method that includes creating a dataset that includes images, one of the images depicting a non-tissue internal reference marker, being linked to non-tissue internal reference marker positional information, and being at least 2-dimensional. Another embodiment is a method that includes receiving a position of an instrument reference marker coupled to an instrument; transforming the position into image space using a position of a non-tissue internal reference marker implanted in a patient; and superimposing a representation of the instrument on an image in which the non-tissue internal reference marker appears. Computer readable media that include machine readable instructions for carrying out the steps of the disclosed methods. Apparatuses, such as integrated circuits, configured to carry out the steps of the disclosed methods. Systems that include devices configured to carry out steps of the disclosed methods.

Methods, apparatuses, and systems useful in conducting image guided interventions

We present a level set framework for implementing editing operators for surfaces. Level set models are deformable implicit surfaces where the deformation of the surface is controlled by a speed function in the level set partial differential equation. In this paper we define a collection of speed functions that produce a set of surface editing operators. The speed functions describe the velocity at each point on the evolving surface in the direction of the surface normal. All of the information needed to deform a surface is encapsulated in the speed function, providing a simple, unified computational framework. The user combines pre-defined building blocks to create the desired speed function. The surface editing operators are quickly computed and may be applied both regionally and globally. The level set framework offers several advantages. 1) By construction, self-intersection cannot occur, which guarantees the generation of physically-realizable, simple, closed surfaces. 2) Level set models easily change topological genus, and 3) are free of the edge connectivity and mesh quality problems associated with mesh models. We present five examples of surface editing operators: blending, smoothing, sharpening, openings/closings and embossing. We demonstrate their effectiveness on several scanned objects and scan-converted models.

/pdf/level-set-surface-editing-operators-znjc0ra6m7.pdf

Level set surface editing operators

The present invention is an OCT imaging system user interface for efficiently providing relevant image displays to the user. These displays are used during image acquisition to align patients and verify acquisition image quality. During image analysis, these displays indicate positional relationships between displayed data images, automatically display suspicious analysis, automatically display diagnostic data, simultaneously display similar data from multiple visits, improve access to archived data, and provide other improvements for efficient data presentation of relevant information.

User interface for efficiently displaying relevant oct imaging data

In this paper, we present a novel method for extracting center axis representations (centerlines) of blood vessels in contrast enhanced (CE)-CTA/MRA, robustly and accurately. This graph-based optimization algorithm which employs multi-scale medialness filters extracts vessel centerlines by computing the minimum-costpaths. Specifically, first, new medialness filters are designed from the assumption of circular/elliptic vessel cross-sections. These filters produce contrast and scale independent responses even the presence of nearby structures. Second, they are incorporated to the minimum-cost path detection algorithm in a novel way for the computational efficiency and accuracy. Third, the full vessel centerline tree is constructed from this optimization technique by assigning a saliency measurefor each centerline from their length and radius information. The proposed method is computationally efficient and produces results that are comparable in quality to the ones created by experts. It has been tested on more than 100 coronary artery data set where the full coronary artery trees are extracted in 21 seconds in average on a 3.2GHz PC.

/pdf/robust-vessel-tree-modeling-1u7n7d76dc.pdf

Robust Vessel Tree Modeling

A method and system for non-invasive assessment of coronary artery stenosis is disclosed. Patient-specific anatomical measurements of the coronary arteries are extracted from medical image data of a patient acquired during rest state. Patient-specific rest state boundary conditions of a model of coronary circulation representing the coronary arteries are calculated based on the patient-specific anatomical measurements and non-invasive clinical measurements of the patient at rest. Patient-specific rest state boundary conditions of the model of coronary circulation representing the coronary arteries are calculated based on the patient-specific anatomical measurements and non-invasive clinical measurements of the patient at rest. Hyperemic blood flow and pressure across at least one stenosis region of the coronary arteries are simulated using the model of coronary circulation and the patient-specific hyperemic boundary conditions. Fractional flow reserve (FFR) is calculated for the at least one stenosis region based on the simulated hyperemic blood flow and pressure.

Method and System for Non-Invasive Functional Assessment of Coronary Artery Stenosis

Various methods have been proposed to extract coronary artery centerlines from computed tomography angiography (CTA) data. Almost all previous approaches are data-driven, which try to trace a centerline from an automatically detected or manually specified coronary ostium. No or little high level prior information is used; therefore, the centerline tracing procedure may terminate early at a severe occlusion or an anatomically inconsistent centerline course may be generated. Though the connectivity of coronary arteries exhibits large variations, the position of major coronary arteries relative to the heart chambers is quite stable. In this work, we propose to exploit the automatically segmented chambers to 1) predict the initial position of the major coronary centerlines and 2) define a vessel-specific region-of-interest (ROI) to constrain the following centerline refinement. The proposed prior constraints have been integrated into a model-driven algorithm for the extraction of three major coronary centerlines, namely the left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). After extracting the major coronary arteries, the side branches are traced using a data-driven approach to handle large anatomical variations in side branches. Experiments on the public Rotterdam coronary CTA database demonstrate the robustness and accuracy of the proposed method. We achieve the best average ranking on overlap metrics among automatic methods and our accuracy metric outperforms all other 22 methods (including both automatic and semi-automatic methods).

/pdf/robust-and-accurate-coronary-artery-centerline-extraction-in-1dz8yyt3x6.pdf

Robust and accurate coronary artery centerline extraction in CTA by combining model-driven and data-driven approaches.

A robust and efficient method for the segmentation of 3D structures in CT and MR images is presented. The proposed method is based on 3D ray propagation by mean shift analysis with a smoothness constraint. Specifically, ray propagation is used to guide an evolving surface due to its computational efficiency. In addition, non-parametric analysis and shape priors are incorporated to the proposed technique for robust convergence. Several examples are depicted to illustrate its effectiveness.

/pdf/segmentation-of-3d-medical-structures-using-robust-ray-2x6zvorq79.pdf

Segmentation of 3D Medical Structures Using Robust Ray Propagation

A method and system for extracting coronary artery centerlines from 3D medical image volumes is disclosed. Heart chambers are segmented in a 3D volume. Coronary artery centerlines are initialized in the 3D volume coronary artery based on the segmented heart chambers. The coronary artery centerlines are locally refined based on a vesselness measure. A length of each coronary artery centerline is shrunk to verify that the coronary artery centerline is within a coronary artery. The coronary artery centerline is the extended using data-driven vessel tracing.

Method and system for coronary artery centerline extraction

We propose local watershed operators for the segmentation of structures, such as medical structures, from an image. A watershed transform is a technique for partitioning an image into many regions while substantially retaining edge information. The proposed watershed operators are a computationally efficient local implementation of watersheds, which can be used as an operator in other segmentation techniques, such as seeded region growing, region competition and markers-based watershed segmentation.

https://link.springer.com/content/pdf/10.1007%2F978-3-540-30135-6_16.pdf

Huseyin Tek

Papers

Method and System for Non-Invasive Functional Assessment of Coronary Artery Stenosis

Robust and accurate coronary artery centerline extraction in CTA by combining model-driven and data-driven approaches.

Segmentation of 3D Medical Structures Using Robust Ray Propagation

Method and system for coronary artery centerline extraction

Local watershed operators for image segmentation