arXiv subjects

Don Krieger

Publications and source records attributed to Don Krieger.

7 recordsLinked to original sources

arXiv2023

The Evolution of Real-time Remote Intraoperative Neurophysiological Monitoring (IONM)

Real-time monitoring of nervous system function with immediate communication of relevant information to the surgeon enables prevention and/or mitigation of iatrogenic injury in many surgical procedures. The hardware and software infrastructure and demonstrated usefulness of telemedicine in support of IONM originated in a busy university health center environment and then spread widely as comparable functional capabilities were added by commercial equipment manufacturers. The earliest implementations included primitive data archival and case documentation capabilities and relied primarily on deidentification for security. They emphasized full-featured control of the real-time data display by remote observers. Today, remote IONM is routinely utilized in more than 200,000 high-risk surgical procedures/year in the United States. For many cases, remote observers rely on screen capture to view the data as it is displayed in the remote operating room while providing sophisticated security capabilities and data archival and standardized metadata and case documentation.

cs.OH↗

arXiv2022

Robust Functional Magnetoencephalographic Brain Measures with 1.0 Millimeter Spatial Separation

Neuroelectric currents were extracted from free-running magnetoencephalographic (MEG) rest and task recordings from 617 normative subjects (ages: 18-87). State-dependent neuroelectric differential activation (DA) with spatial resolution comparable to that of local field potentials was detected in the majority of this cohort. Rest-high (rest greater than task) or task-high DA was found in the majority of individual subjects in more than 13,000 1 mm^3 voxels per subject. On average, 6% of the DA voxels bordered a second voxel whose DA was opposite, i.e., one was rest-high and the other was task-high. 516 subjects showed more than 100 such opposite voxel pairs 1 mm apart; 226 subjects showed more than 1000. The number of bordering voxel pairs with the same DA was consistently higher for almost all subjects and averaged 20%, ruling out the possibility that opposite bordering voxels occur simply by chance. For 65 brain regions, more than 10% of the cohort showed significantly more same than opposite pairs. These findings taken together support the conclusion that neuroelectric DA is consistently distinguishable at single 1 mm^3 brain voxels with 1-mm spatial separation. When restricted to voxels with near-zero rest or task counts, significantly more rest-high than task-high voxels were found in 35 regions for at least 10 percent of the subjects. This inequality was not found when all DA-voxels were included. This supports the conclusion that the DA found in many rest-high voxels with near-zero task counts is due in part to task-dependent inhibition.

q-bio.NC↗

arXiv2022

Random Access Concatenated Libraries and dd enable a short-latency high-content website on an inexpensive shared server

Content-rich websites typically house their images as individual files or as more costly binary database objects. Both methods place high demands on storage resources with commensurate high monetary cost. Inexpensive shared service accounts come with strict limits on disk and computing resources which prevent their use for hosting content-rich websites. To minimize the load on these limited resources, large numbers of images or other records may be concatenated into a single file and delivered with short latency independent of location within the file using Linux utility dd. This solution and its performance are presented for (a) a website which houses 8000+ genealogical reference books with more than 3.5 million 250-Kbyte page images, (b) a website-based database of 86 million death records, and (c) a cluster computing application which utilizes 800 neuroimaging databases, each with 1.5 million records. These disparate applications demonstrate the efficacy, scalability, and general utility of the solution.

cs.DB↗

arXiv2018

Normative atlases of neuroelectric brain activity and connectivity from a large human cohort

Magnetoencephalographic (MEG) recordings from a large normative cohort (n = 619) were processed to extract measures of regional neuroelectric activity. The overall objective of the effort was to use these measures to identify normative human neuroelectric brain function. The aims were (a) to identify and measure the values and range of those neuroelectric properties which are common to the cohort, (b) to identify and measure the values and range of those neuroelectric properties which distinguish one individual from another, and (c) to identify relationships of the measures to properties of the individual, e.g. sex, biological age, and sleep symptoms. It is hoped that comparison of the resultant established norms to measures from recordings of symptomatic individuals will enable advances is our understanding of pathology. MEG recordings during resting and task conditions were provided by The Cambridge (UK) Centre for Ageing and Neuroscience Stage 2 cohort study. Referee consensus processing was used to localize and validate neuroelectric currents, p < 10-12 for each, p < 10-4 for each when corrected for multiple comparisons. Comparisons of regional activity and connectivity within-subjects produced profuse reliable measures detailing differences between individuals, p < 10-8 for each comparison, p < 0.005 for each when corrected for a total of 5 x 105 comparisons. Cohort-wide regional comparisons (p < 10-8 for each) produced profuse measures which were common to the preponderance of individuals, detailing normative commonalities in brain function. Comparisons of regional gray matter (cellular) vs white matter (communication fibers) activity produced robust differences both cohort-wide and for each individual. These results validate the high spatial resolution of the results and establish the unprecedented ability to obtain neuroelectric measures from the white matter.

q-bio.NC↗

arXiv2018

MEG-Derived Functional Tractography, Results for Normal and Concussed Cohorts

Measures of neuroelectric activity from each of 18 automatically identified white matter tracts were extracted from resting MEG recordings from a normative, n=588, and a chronic TBI, traumatic brain injury, n=63, cohort, 60 of whose TBIs were mild. Activity in the TBI cohort was significantly reduced compared with the norms for ten of the tracts, p < 10-6 for each. Significantly reduced activity (p < 10-3) was seen in more than one tract in seven mTBI individuals and one member of the normative cohort.

q-bio.NC↗

arXiv2018

Seemless Utilization of Heterogeneous XSede Resources to Accelerate Processing of a High Value Functional Neuroimaging Dataset

We describe the technical effort used to process a voluminous high value human neuroimaging dataset on the Open Science Grid with opportunistic use of idle HPC resources to boost computing capacity more than 5-fold. With minimal software development effort and no discernable competitive interference with other HPC users, this effort delivered 15,000,000 core hours over 7 months.

q-bio.NC↗

arXiv2017

Shared High Value Research Resources: The CamCAN Human Lifespan Neuroimaging Dataset Processed on the Open Science Grid

The CamCAN Lifespan Neuroimaging Dataset, Cambridge (UK) Centre for Ageing and Neuroscience, was acquired and processed beginning in December, 2016. The referee consensus solver deployed to the Open Science Grid was used for this task. The dataset includes demographic and screening measures, a high-resolution MRI scan of the brain, and whole-head magnetoencephalographic (MEG) recordings during eyes closed rest (560 sec), a simple task (540 sec), and passive listening/viewing (140 sec). The data were collected from 619 neurologically normal individuals, ages 18-87. The processed results from the resting recordings are completed and available online. These constitute 1.7 TBytes of data including the location within the brain (1 mm resolution), time stamp (1 msec resolution), and 80 msec time course for each of 3.7 billion validated neuroelectric events, i.e. mean 6.1 million events for each of the 619 participants. The referee consensus solver provides high yield (mean 11,000 neuroelectric currents/sec; standard deviation (sd): 3500/sec) high confidence (p < 10-12 for each identified current) measures of the neuroelectric currents whose magnetic fields are detected in the MEG recordings. We describe the solver, the implementation of the solver deployed on the Open Science Grid, the workflow management system, the opportunistic use of high performance computing (HPC) resources to add computing capacity to the Open Science Grid reserved for this project, and our initial findings from the recently completed processing of the resting recordings. This required 14 million core hours, i.e. 40 core hours per second of data.

q-bio.NC↗