scholarly journals Registration-free workflow for electromagnetic and optical navigation in orbital and craniofacial surgery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Schreurs ◽  
F. Baan ◽  
C. Klop ◽  
L. Dubois ◽  
L. F. M. Beenen ◽  
...  
Keyword(s):  
Reference Frame ◽  
Optical Tracking ◽  
Imaging Data ◽  
Clinical Implementation ◽  
Virtual Planning ◽  
Non Invasive ◽  
Registration Procedure ◽  
Dental Model ◽  
Set Up ◽  
Maxillary Dentition

AbstractThe accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that eliminates the need for a registration procedure altogether: registration-free navigation. In the workflow, the maxillary dental model is fused to the pre-operative imaging data using commercially available virtual planning software. A virtual Dynamic Reference Frame on a splint is designed on the patient’s fused maxillary dentition: during surgery, the splint containing the reference frame is positioned on the patient’s dentition. This alleviates the need for any registration procedure, since the position of the reference frame is known from the design. The accuracy of the workflow was evaluated in a cadaver set-up, and compared to bone-anchored fiducial, virtual splint and surface-based registration. The results showed that accuracy of the workflow was greatly dependent on tracking technique used: the workflow was the most accurate with electromagnetic tracking, but the least accurate with optical tracking. Although this method offers a time-efficient, non-invasive, radiation-free automatic alternative for registration, clinical implementation is hampered by the unexplained differences in accuracy between tracking techniques.

scholarly journals Registration-Free Workflow for Electromagnetic and Optical Navigation in Orbital and Craniofacial Surgery

2020 ◽  
Author(s):  
Ruud Schreurs ◽  
Frank Baan ◽  
Cornelis Klop ◽  
Leander Dubois ◽  
Ludo Beenen ◽  
...  
Keyword(s):  
Reference Frame ◽  
Optical Tracking ◽  
Imaging Data ◽  
Clinical Implementation ◽  
Virtual Planning ◽  
Non Invasive ◽  
Registration Procedure ◽  
Dental Model ◽  
Set Up ◽  
Maxillary Dentition

Abstract The accuracy of intra-operative navigation is largely dependent on the intra-operative registration procedure. Next to accuracy, important factors to consider for the registration procedure are invasiveness, time consumption, logistical demands, user-dependency, compatibility and radiation exposure. In this study, a workflow is presented that eliminates the need for a registration procedure altogether: registration-free navigation. In the workflow, the maxillary dental model is fused to the pre-operative imaging data using commercially available virtual planning software. A virtual Dynamic Reference Frame on a splint is designed on the patient’s fused maxillary dentition: during surgery, the splint containing the reference frame is positioned on the patient’s dentition. This alleviates the need for any registration procedure, since the position of the reference frame is known from the design. The accuracy of the workflow was evaluated in a cadaver set-up, and compared to bone-anchored fiducial, virtual splint and surface-based registration. The results showed that accuracy of the workflow was greatly dependent on tracking technique used: the workflow was the most accurate with electromagnetic tracking, but the least accurate with optical tracking. Although this method offers a time-efficient, non-invasive, radiation-free automatic alternative for registration, clinical implementation is hampered by the unexplained differences in accuracy between tracking techniques.

scholarly journals Hydraulic insertions of cochlear implant electrode arrays into the human cadaver cochlea: preliminary findings

2021 ◽  
Author(s):  
M. Geraldine ◽  
Thomas Lenarz ◽  
Thomas S. Rau
Keyword(s):  
Cochlear Implant ◽  
Outcome Measurement ◽  
Round Window ◽  
Handling Time ◽  
Human Cadaver ◽  
Hydraulic Actuator ◽  
Electrode Arrays ◽  
Non Invasive ◽  
Insertion Tool ◽  
Set Up

Abstract Objectives (1) To evaluate the feasibility of a non-invasive, novel, simple insertion tool to perform automated, slow insertions of cochlear implant electrode arrays (EA) into a human cadaver cochlea; (2) to estimate the handling time required by our tool. Methods Basic science study conducted in an experimental OR. Two previously anonymized human cadaver heads, three commercially available EAs, and our novel insertion tool were used for the experiments. Our tool operates as a hydraulic actuator that delivers an EA at continuous velocities slower than manually feasible. Intervention(s): the human cadaver heads were prepared with a round-window approach for CI surgery in a standard fashion. Twelve EA insertion trials using our tool involved: non-invasive fixation of the tool to the head; directing the tool to the round window and EA mounting onto the tool; automated EA insertion at approximately 0.1 mm/s driven by hydraulic actuation. Outcome measurement(s): handling time of the tool; post-insertion cone-beam CT scans to provide intracochlear evaluation of the EA insertions. Results Our insertion tool successfully inserted an EA into the human cadaver cochlea (n = 12) while being attached to the human cadaver head in a non-invasive fashion. Median time to set up the tool was 8.8 (7.2–9.4) min. Conclusion The first insertions into the human cochlea using our novel, simple insertion tool were successful without the need for invasive fixation. The tool requires < 10 min to set up, which is clinically acceptable. Future assessment of intracochlear trauma is needed to support its safety profile for clinical translation.

scholarly journals Identification of Tumor-Specific MRI Biomarkers Using Machine Learning (ML)

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 742
Author(s):  
Rima Hajjo ◽  
Dima A. Sabbah ◽  
Sanaa K. Bardaweel ◽  
Alexander Tropsha
Keyword(s):  
Machine Learning ◽  
High Specificity ◽  
Cancer Biomarkers ◽  
Cancer Prognosis ◽  
Current Status ◽  
Imaging Data ◽  
Non Invasive ◽  
Machine Learning Methods ◽  
Cancer Types ◽  
Magnetic Resonance Imaging Mri

The identification of reliable and non-invasive oncology biomarkers remains a main priority in healthcare. There are only a few biomarkers that have been approved as diagnostic for cancer. The most frequently used cancer biomarkers are derived from either biological materials or imaging data. Most cancer biomarkers suffer from a lack of high specificity. However, the latest advancements in machine learning (ML) and artificial intelligence (AI) have enabled the identification of highly predictive, disease-specific biomarkers. Such biomarkers can be used to diagnose cancer patients, to predict cancer prognosis, or even to predict treatment efficacy. Herein, we provide a summary of the current status of developing and applying Magnetic resonance imaging (MRI) biomarkers in cancer care. We focus on all aspects of MRI biomarkers, starting from MRI data collection, preprocessing and machine learning methods, and ending with summarizing the types of existing biomarkers and their clinical applications in different cancer types.

scholarly journals Head models of healthy and depressed adults for simulating the effects of non-invasive brain stimulation

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 704 ◽  
Author(s):  
Nya Mehnwolo Boayue ◽  
Gábor Csifcsák ◽  
Oula Puonti ◽  
Axel Thielscher ◽  
Matthias Mittner
Keyword(s):  
Electric Fields ◽  
Brain Stimulation ◽  
Brain Anatomy ◽  
Imaging Data ◽  
Magnetic Resonance Imaging Data ◽  
Structural Variations ◽  
Major Depressive ◽  
Non Invasive ◽  
The Past ◽  
Dorsolateral Prefrontal

During the past decade, it became clear that the effects of non-invasive brain stimulation (NIBS) techniques such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) are substantially influenced by variations in individual head and brain anatomy. In addition to structural variations in the healthy, several psychiatric disorders are characterized by anatomical alterations that are likely to further constrain the intracerebral effects of NIBS. Here, we present high-resolution realistic head models derived from structural magnetic resonance imaging data of 19 healthy adults and 19 patients diagnosed with major depressive disorder (MDD). By using a freely available software package for modelling the effects of different NIBS protocols, we show that our head models are well-suited for assessing inter-individual and between-group variability in the magnitude and focality of tDCS-induced electric fields for two protocols targeting the left dorsolateral prefrontal cortex.

scholarly journals Factors affecting cell-free DNA fetal fraction: statistical analysis of 13,661 maternal plasmas for non-invasive prenatal screening

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Yaping Hou ◽  
Jiexia Yang ◽  
Yiming Qi ◽  
Fangfang Guo ◽  
Haishan Peng ◽  
...  
Keyword(s):  
Gestational Age ◽  
Maternal Age ◽  
Prenatal Screening ◽  
Maternal Plasma ◽  
Clinical Implementation ◽  
Factors Affecting ◽  
Non Invasive ◽  
Cell Free Fetal Dna ◽  
Maternal Bmi ◽  
Fetal Fraction

Abstract Background The identification of cell-free fetal DNA (cffDNA) facilitated non-invasive prenatal screening (NIPS) through analysis of cffDNA in maternal plasma. However, challenges regarding its clinical implementation become apparent. Factors affecting fetal fraction should be clarified to guide its clinical application. Results A total of 13,661 pregnant subjects with singleton pregnancies who undertook NIPS were included in the study. Relationship of gestational age, maternal BMI, and maternal age with the cffDNA fetal fraction in maternal plasmas for NIPS was investigated. Compared with 13 weeks (12.74%) and 14–18 weeks group (12.73%), the fetal fraction in gestational ages of 19–23 weeks, 24–28 weeks, and more than 29 weeks groups significantly increased to 13.11%, 16.14%, and 21.17%, respectively (P < 0.01). Compared with fetal fraction of 14.54% in the maternal BMI group of < 18.5 kg/m2, the percentage of fetal fraction in the group of 18.5–24.9 kg/m2 (13.37%), 25–29.9 kg/m2 (12.20%), 30–34.9 kg/m2 (11.32%), and 35–39.9 kg/m2 (11.57%) decreased significantly (P < 0.01). Compared with the fetal fraction of 14.38% in the group of 18–24 years old, the fetal fraction in the maternal age group of 25–29 years old group (13.98%) (P < 0.05), 30–34 years old group (13.18%) (P < 0.01), 35–39 years old group (12.34%) (P < 0.01), and ≥ 40 years old (11.90%) group (P < 0.01) decreased significantly. Conclusions The percentage of fetal fraction significantly increased with increase of gestational age. Decreased fetal fraction with increasing maternal BMI was found. Maternal age was also negatively related to the fetal fraction.

P201 A remote pathway for inpatient home non-invasive ventilation set-up

2018 ◽  
Author(s):  
L Flight ◽  
S Dixon ◽  
B Khan ◽  
R Bhalla ◽  
H Aminy-Raouf ◽  
...  
Keyword(s):  
Invasive Ventilation ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Set Up

scholarly journals Herschel Footprint Database and Service

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
E. Varga-Verebélyi ◽  
L. Dobos ◽  
T. Budavári ◽  
Cs. Kiss
Keyword(s):  
Web Services ◽  
Data Model ◽  
Geometric Form ◽  
Imaging Data ◽  
Space Observatory ◽  
Herschel Space Observatory ◽  
Search Tool ◽  
Set Up

AbstractWe created the Herschel1 Footprint Database and web services for the Herschel Space Observatory imaging data. For this database we set up a unified data model for the PACS and SPIRE Herschel instruments, from the pointing and header information of each observation, generated and stored sky coverages (footprints) of the observations in their exact geometric form. With this tool we extend the capabilities of the Herschel Science Archive by providing an effective search tool that is able to find observations for selected sky locations (objects), or even in larger areas in the sky.

Application of the GWPS for Machining of a Transmission Housing

2000 ◽  
Author(s):  
Suren B. Rao ◽  
Gary L. Neal ◽  
Edward C. DeMeter ◽  
Martin W. Trethewey
Keyword(s):  
Reference Frame ◽  
Surface Current ◽  
Prototype System ◽  
Specific Information ◽  
Accuracy And Precision ◽  
Machining System ◽  
Housing Component ◽  
Set Up ◽  
Novel Concept ◽  
Machining Operations

Abstract One component of a modern machining system that has remained virtually unchanged, since time immemorial, is part location. The fundamental basis of current methods of part location is the concept of a physical datum surface, which is created in the first machining operation and conducting all the further machining operations with reference to this physical surface. Current workpiece positioning practice utilizes physical contacts between the fixture and workpiece for location. Due to contact feature variations, the positioning is inconsistent and variable for sequential machining set-ups. Consequently, geometric errors are induced in machined features. This paper proposes a novel concept, the Global Workpiece Positioning System (GWPS), for datum establishment. Precision artifacts are strategically located on the rough workpiece and a part reference frame is defined, with respect to these artifacts, at a qualification station. This part specific information now travels with the part to the machining station. At the machining station a probe is used to locate the artifacts on the part and determine their location with reference to the machine tool’s reference frame. Since the part reference frame is known with respect to the artifacts, its location can be derived with respect to the machine tool’s reference frame. The part program can then be modified to reflect the actual location of the part and the machining of the features carried out with a greater degree of accuracy and precision. A prototype system using the GWPS concept is implemented and presented. Experimental results validate the GWPS concept. A three-hole pattern is drilled and bored in an aircraft transmission housing component in a two set up operation. The GWPS located workpieces retained a hole center location accuracy within the required drawing specification without the use of the traditional location fixtures that are typically used for the two operational set-ups.

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