scholarly journals An open-source real-time ultrasound reconstruction system for four-dimensional imaging of moving organs

2009 ◽  
Author(s):  
Danielle Pace ◽  
David Gobbi ◽  
Chris Wedlake ◽  
Jan Gumprecht ◽  
Jonathan Boisvert ◽  
...  
Keyword(s):  
Open Source ◽  
Real Time ◽  
Spatial Resolution ◽  
Imaging System ◽  
Imaging Modality ◽  
Motion Artifacts ◽  
Computer Assisted ◽  
Source Imaging ◽  
3D Slicer ◽  
4D Ultrasound

Four-dimensional imaging is a necessary step in computer-assisted interventions (CAI) performed on moving surgical targets, such as those located within the beating heart or influenced by respiratory motion. Ultrasound (US) is often the best imaging modality for this application, as it provides good contrast and spatial resolution while remaining simple to integrate into the operating room. However, conventional 2D US imaging is often insufficient for preoperative planning and surgical guidance, real-time 3D ultrasound imaging using matrix array probes has a smaller field of view and lower spatial resolution, and 3D volumes created using 3D US reconstruction suffer from motion artifacts. As an alternative, gated 4D ultrasound reconstruction using a tracked 2D US probe is a promising technology. In this paper, we present SynchroGrab4D to the open-source community. SynchroGrab4D performs 3D and 4D US reconstruction in real-time while visualizing the output volume(s) within an OpenIGTLink-compliant CAI system, such as 3D Slicer. Also included are VTK classes that perform ECG-gating and that interface with several commercial tracking systems, as well as a 4D Imaging module in 3D Slicer. Our open-source imaging system can be used to collect the 4D image data required for computer-assisted surgical planning and intraoperative guidance for a variety of moving organs.

scholarly journals Enhanced Contactless Vital Sign Estimation from Real-Time Multimodal 3D Image Data

2020 ◽  
Vol 6 (11) ◽  
pp. 123
Author(s):  
Chen Zhang ◽  
Ingo Gebhart ◽  
Peter Kühmstedt ◽  
Maik Rosenberger ◽  
Gunther Notni
Keyword(s):  
Real Time ◽  
3D Imaging ◽  
Imaging System ◽  
Vital Signs ◽  
Image Data ◽  
Motion Artifacts ◽  
Video Data ◽  
Ambient Light ◽  
3D Image ◽  
Controlled Illumination

The contactless estimation of vital signs using conventional color cameras and ambient light can be affected by motion artifacts and changes in ambient light. On both these problems, a multimodal 3D imaging system with an irritation-free controlled illumination was developed in this work. In this system, real-time 3D imaging was combined with multispectral and thermal imaging. Based on 3D image data, an efficient method was developed for the compensation of head motions, and novel approaches based on the use of 3D regions of interest were proposed for the estimation of various vital signs from multispectral and thermal video data. The developed imaging system and algorithms were demonstrated with test subjects, delivering a proof-of-concept.

MITK-OpenIGTLink for combining open-source toolkits in real-time computer-assisted interventions

2016 ◽  
Vol 12 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Martin Klemm ◽  
Thomas Kirchner ◽  
Janek Gröhl ◽  
Dominique Cheray ◽  
Marco Nolden ◽  
...  
Keyword(s):  
Open Source ◽  
Real Time ◽  
Computer Assisted

A System for Visualizing and Assessing Electromagnetic Tracking Error during Computer-­‐assisted Surgery

2018 ◽  
Author(s):  
Vinyas Harish
Keyword(s):  
Open Source ◽  
Real Time ◽  
Random Noise ◽  
Tracking Error ◽  
Computer Assisted Surgery ◽  
Ground Truth ◽  
Optical Tracking ◽  
Computer Assisted ◽  
Electromagnetic Tracking ◽  
Surgical Equipment

PURPOSE: Electromagnetic tracking is used in image-­‐guided interventions to monitor the position of surgical equipment. However, it is prone to error. During navigation procedures, the measurement and visualization of error should take place to ensure precision and accuracy. Our goal was to extend open-­‐source software such that no programming from the user is needed for error monitoring.   METHODS: The electromagnetic tracking error was defined as the difference in position readings of a surgical stylus that was optically and electromagnetically tracked. The optical tracking reading was considered ground truth as it is unaffected by metal objects. The stylus was moved freehandedly within a region of interest to quickly sample electromagnetic tracking error, including error caused by field-­‐distortion inducing ferromagnetic materials and random noise. All tracked devices were used in a plug-­‐and-­‐play manner. Measurements were visualized in real-­‐time in 3D Slicer, an open-­‐ source platform for medical image computing (www.slicer.org).   RESULTS: To determine the reproducibility of the data collected by our system, the tracking error was measured in regions of interest representing a surgeon’s workspace. Tests were done with and without metal objects placed in the workspace. A quick freehand sampling procedure was sufficient to detect error. Freehand measurements within a controlled environment reported distortion values of 1.16 mm (STD 0.71 mm). Measurements taken with a metal rod and parts from a surgical retractor kit were 4.27 mm (STD 2.92 mm) and 8.26 mm (STD 2.08 mm), respectively.   CONCLUSION: Our system shows promise for the real-­‐time visualization of electromagnetic tracking error during computer-­‐assisted surgical procedures

scholarly journals Development of open source software for computer-assisted intervention systems

2005 ◽  
Author(s):  
Peter Kazanzides ◽  
Anton Deguet ◽  
Ankur Kapoor ◽  
Ofri Sadowsky ◽  
Andy LaMora ◽  
...  
Keyword(s):  
Open Source ◽  
Real Time ◽  
Open Source Software ◽  
Servo Control ◽  
Computer Assisted ◽  
Medical Robots ◽  
The Real ◽  
Software Libraries ◽  
Performance Requirements ◽  
Hardware Interface

We are developing open source software for computer assisted intervention systems. Our primary experience has been with medical robots, but the concepts (and software) apply to many physical devices that interact with the real world. The real-time performance requirements permeate all levels of our software, including common tools (such as logging, class and object registers), vectors, matrices and transformations. Our software libraries are written in C++, but are also accessible from Python, which provides a convenient environment for rapid prototyping and interactive testing. The real-time support includes a device (hardware) interface and a task library. Device-specific modules such as robot servo control and trajectory generation can be provided by tasks or by external devices. Ultimately, we intend to provide a framework that supports extension via dynamically loaded plug-in modules. Our development process utilizes a multitude of open source tools, including CVS, CMake, Swig, CppUnit, Dart, CVSTrac, Doxygen and LaTeX. These tools help to ensure compliance with our software development procedure.

Ambulatory Assessment

2009 ◽  
Vol 14 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Ulrich W. Ebner-Priemer ◽  
Timothy J. Trull
Keyword(s):  
Real Time ◽  
Clinical Psychology ◽  
Real Life ◽  
Ambulatory Assessment ◽  
Computer Assisted ◽  
Affective Valence ◽  
Time Data ◽  
Physiological Processes ◽  
Context Specific ◽  
Questionnaire Studies

Convergent experimental data, autobiographical studies, and investigations on daily life have all demonstrated that gathering information retrospectively is a highly dubious methodology. Retrospection is subject to multiple systematic distortions (i.e., affective valence effect, mood congruent memory effect, duration neglect; peak end rule) as it is based on (often biased) storage and recollection of memories of the original experience or the behavior that are of interest. The method of choice to circumvent these biases is the use of electronic diaries to collect self-reported symptoms, behaviors, or physiological processes in real time. Different terms have been used for this kind of methodology: ambulatory assessment, ecological momentary assessment, experience sampling method, and real-time data capture. Even though the terms differ, they have in common the use of computer-assisted methodology to assess self-reported symptoms, behaviors, or physiological processes, while the participant undergoes normal daily activities. In this review we discuss the main features and advantages of ambulatory assessment regarding clinical psychology and psychiatry: (a) the use of realtime assessment to circumvent biased recollection, (b) assessment in real life to enhance generalizability, (c) repeated assessment to investigate within person processes, (d) multimodal assessment, including psychological, physiological and behavioral data, (e) the opportunity to assess and investigate context-specific relationships, and (f) the possibility of giving feedback in real time. Using prototypic examples from the literature of clinical psychology and psychiatry, we demonstrate that ambulatory assessment can answer specific research questions better than laboratory or questionnaire studies.

scholarly journals Target tracking accuracy and latency with different 4D ultrasound systems – a robotic phantom study

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Svenja Ipsen ◽  
Sven Böttger ◽  
Holger Schwegmann ◽  
Floris Ernst
Keyword(s):  
Target Tracking ◽  
Real Time ◽  
Template Matching ◽  
Image Data ◽  
Distinct Advantage ◽  
Reference Trajectory ◽  
Data Streaming ◽  
Tracking Accuracy ◽  
Time Data ◽  
4D Ultrasound

AbstractUltrasound (US) imaging, in contrast to other image guidance techniques, offers the distinct advantage of providing volumetric image data in real-time (4D) without using ionizing radiation. The goal of this study was to perform the first quantitative comparison of three different 4D US systems with fast matrix array probes and real-time data streaming regarding their target tracking accuracy and system latency. Sinusoidal motion of varying amplitudes and frequencies was used to simulate breathing motion with a robotic arm and a static US phantom. US volumes and robot positions were acquired online and stored for retrospective analysis. A template matching approach was used for target localization in the US data. Target motion measured in US was compared to the reference trajectory performed by the robot to determine localization accuracy and system latency. Using the robotic setup, all investigated 4D US systems could detect a moving target with sub-millimeter accuracy. However, especially high system latency increased tracking errors substantially and should be compensated with prediction algorithms for respiratory motion compensation.

Feasibility and Clinical Utility of Ultra-Widefield–Navigated Swept-Source Optical Coherence Tomography Imaging

2021 ◽  
pp. 247412642199733
Author(s):  
Kyle D. Kovacs ◽  
M. Abdallah Mahrous ◽  
Luis Gonzalez ◽  
Benjamin E. Botsford ◽  
Tamara L. Lenis ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Clinical Utility ◽  
Clinical Decision Making ◽  
Imaging System ◽  
Imaging Modality ◽  
Case Series ◽  
Subretinal Fluid ◽  
Optical Coherence ◽  
Swept Source ◽  
Oct Imaging

Purpose: This work aims to evaluate the clinical utility and feasibility of a novel scanning laser ophthalmoscope-based navigated ultra-widefield swept-source optical coherence tomography (UWF SS-OCT) imaging system. Methods: A retrospective, single-center, consecutive case series evaluated patients between September 2019 and October 2020 with UWF SS-OCT (modified Optos P200TxE, Optos PLC) as part of routine retinal care. The logistics of image acquisition, interpretability of images captured, nature of the peripheral abnormality, and clinical utility in management decisions were recorded. Results: Eighty-two eyes from 72 patients were included. Patients were aged 59.4 ± 17.1 years (range, 8-87 years). During imaging, 4.4 series of images were obtained in 4.1 minutes, with 86.4% of the image series deemed to be diagnostic of the peripheral pathology on blinded image review. The most common pathologic findings were chorioretinal scars (18 eyes). In 31 (38%) eyes, these images were meaningful in supporting clinical decision-making with definitive findings. Diagnoses imaged included retinal detachment combined with retinoschisis, retinal hole with overlying vitreous traction and subretinal fluid, vitreous inflammation overlying a peripheral scar, Coats disease, and peripheral retinal traction in sickle cell retinopathy. Conclusions: Navigated UWF SS-OCT imaging was clinically practical and provided high-quality characterization of peripheral retinal lesions for all eyes. Images directly contributed to management plans, including laser, injection or surgical treatment, for a clinically meaningful set of patients (38%). Future studies are needed to further assess the value of this imaging modality and its role in diagnosing, monitoring, and treating peripheral lesions.

scholarly journals Unsupervised Sub-Pixel Water Body Mapping with Sentinel-3 OLCI Image

2019 ◽  
Vol 11 (3) ◽  
pp. 327 ◽  
Author(s):  
Xia Wang ◽  
Feng Ling ◽  
Huaiying Yao ◽  
Yaolin Liu ◽  
Shuna Xu
Keyword(s):  
Surface Water ◽  
Real Time ◽  
Spatial Resolution ◽  
Water Body ◽  
Land Surface ◽  
Clustering Algorithm ◽  
Body Mapping ◽  
Water Index ◽  
Land Surface Water ◽  
Body Map

Mapping land surface water bodies from satellite images is superior to conventional in situ measurements. With the mission of long-term and high-frequency water quality monitoring, the launch of the Ocean and Land Colour Instrument (OLCI) onboard Sentinel-3A and Sentinel-3B provides the best possible approach for near real-time land surface water body mapping. Sentinel-3 OLCI contains 21 bands ranging from visible to near-infrared, but the spatial resolution is limited to 300 m, which may include lots of mixed pixels around the boundaries. Sub-pixel mapping (SPM) provides a good solution for the mixed pixel problem in water body mapping. In this paper, an unsupervised sub-pixel water body mapping (USWBM) method was proposed particularly for the Sentinel-3 OLCI image, and it aims to produce a finer spatial resolution (e.g., 30 m) water body map from the multispectral image. Instead of using the fraction maps of water/non-water or multispectral images combined with endmembers of water/non-water classes as input, USWBM directly uses the spectral water index images of the Normalized Difference Water Index (NDWI) extracted from the Sentinel-3 OLCI image as input and produces a water body map at the target finer spatial resolution. Without the collection of endmembers, USWBM accomplished the unsupervised process by developing a multi-scale spatial dependence based on an unsupervised sub-pixel Fuzzy C-means (FCM) clustering algorithm. In both validations in the Tibet Plate lake and Poyang lake, USWBM produced more accurate water body maps than the other pixel and sub-pixel based water body mapping methods. The proposed USWBM, therefore, has great potential to support near real-time sub-pixel water body mapping with the Sentinel-3 OLCI image.

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