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13
result(s) for
"Addison, Anthony P."
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Noncontact Respiratory Monitoring Using Depth Sensing Cameras: A Review of Current Literature
2021
There is considerable interest in the noncontact monitoring of patients as it allows for reduced restriction of patients, the avoidance of single-use consumables and less patient–clinician contact and hence the reduction of the spread of disease. A technology that has come to the fore for noncontact respiratory monitoring is that based on depth sensing camera systems. This has great potential for the monitoring of a range of respiratory information including the provision of a respiratory waveform, the calculation of respiratory rate and tidal volume (and hence minute volume). Respiratory patterns and apneas can also be observed in the signal. Here we review the ability of this method to provide accurate and clinically useful respiratory information.
Journal Article
Continuous non‐contact respiratory rate and tidal volume monitoring using a Depth Sensing Camera
2022
The monitoring of respiratory parameters is important across many areas of care within the hospital. Here we report on the performance of a depth-sensing camera system for the continuous non-contact monitoring of Respiratory Rate (RR) and Tidal Volume (TV), where these parameters were compared to a ventilator reference. Depth sensing data streams were acquired and processed over a series of runs on a single volunteer comprising a range of respiratory rates and tidal volumes to generate depth-based respiratory rate (RR
depth
) and tidal volume (TV
depth
) estimates. The bias and root mean squared difference (RMSD) accuracy between RR
depth
and the ventilator reference, RR
vent
, across the whole data set was found to be -0.02 breaths/min and 0.51 breaths/min respectively. The least squares fit regression equation was determined to be: RR
depth
= 0.96 × RR
vent
+ 0.57 breaths/min and the resulting Pearson correlation coefficient, R, was 0.98 (p < 0.001). Correspondingly, the bias and root mean squared difference (RMSD) accuracy between TV
depth
and the reference TV
vent
across the whole data set was found to be − 0.21 L and 0.23 L respectively. The least squares fit regression equation was determined to be: TV
depth
= 0.79 × TV
vent
—0.01 L and the resulting Pearson correlation coefficient, R, was 0.92 (p < 0.001). In conclusion, a high degree of agreement was found between the depth-based respiration rate and its ventilator reference, indicating that RR
depth
is a promising modality for the accurate non-contact respiratory rate monitoring in the clinical setting. In addition, a high degree of correlation between depth-based tidal volume and its ventilator reference was found, indicating that TV
depth
may provide a useful monitor of tidal volume trending in practice. Future work should aim to further test these parameters in the clinical setting.
Journal Article
A feasible route for the design and manufacture of customised respiratory protection through digital facial capture
by
Reed, Caroline A.
,
Morrell, Alexander P.
,
Coward, Trevor
in
639/166/985
,
692/700
,
692/700/3160
2021
The World Health Organisation has called for a 40% increase in personal protective equipment manufacturing worldwide, recognising that frontline workers need effective protection during the COVID-19 pandemic. Current devices suffer from high fit-failure rates leaving significant proportions of users exposed to risk of viral infection. Driven by non-contact, portable, and widely available 3D scanning technologies, a workflow is presented whereby a user’s face is rapidly categorised using relevant facial parameters. Device design is then directed down either a semi-customised or fully-customised route. Semi-customised designs use the extracted eye-to-chin distance to categorise users in to pre-determined size brackets established via a cohort of 200 participants encompassing 87.5% of the cohort. The user’s nasal profile is approximated to a Gaussian curve to further refine the selection in to one of three subsets. Flexible silicone provides the facial interface accommodating minor mismatches between true nasal profile and the approximation, maintaining a good seal in this challenging region. Critically, users with outlying facial parameters are flagged for the fully-customised route whereby the silicone interface is mapped to 3D scan data. These two approaches allow for large scale manufacture of a limited number of design variations, currently nine through the semi-customised approach, whilst ensuring effective device fit. Furthermore, labour-intensive fully-customised designs are targeted as those users who will most greatly benefit. By encompassing both approaches, the presented workflow balances manufacturing scale-up feasibility with the diverse range of users to provide well-fitting devices as widely as possible. Novel flow visualisation on a model face is presented alongside qualitative fit-testing of prototype devices to support the workflow methodology.
Journal Article
Measuring Up: A Comparison of TapeStation 4200 and Bioanalyzer 2100 as Measurement Tools for RNA Quality in Postmortem Human Brain Samples
2023
The determination of RNA integrity is a critical quality assessment tool for gene expression studies where the experiment’s success is highly dependent on the sample quality. Since its introduction in 1999, the gold standard in the scientific community has been the Agilent 2100 Bioanalyzer’s RNA integrity number (RIN), which uses a 1–10 value system, from 1 being the most degraded, to 10 being the most intact. In 2015, Agilent launched 4200 TapeStation’s RIN equivalent, and reported a strong correlation of r2 of 0.936 and a median error < ±0.4 RIN units. To evaluate this claim, we compared the Agilent 4200 TapeStation’s RIN equivalent (RINe) and DV200 to the Agilent 2100 Bioanalyzer’s RIN for 183 parallel RNA samples. In our study, using RNA from a total of 183 human postmortem brain samples, we found that the RIN and RINe values only weakly correlate, with an r2 of 0.393 and an average difference of 3.2 RIN units. DV200 also only weakly correlated with RIN (r2 of 0.182) and RINe (r2 of 0.347). Finally, when applying a cut-off value of 6.5 for both metrics, we found that 95.6% of samples passed with RIN, while only 23.5% passed with RINe. Our results suggest that even though RIN (Bioanalyzer) and RINe (TapeStation) use the same 1–10 value system, they should not be used interchangeably, and cut-off values should be calculated independently.
Journal Article
Kinematic data profile and clinical outcomes in robotic inguinal hernia repairs: a pilot study
2023
BackgroundSurgical training requires clinical knowledge and technical skills to operate safely and optimize clinical outcomes. Technical skills are hard to measure. The Intuitive Data Recorder (IDR), (Sunnyvale, CA) allows for the measurement of technical skills using objective performance indicators (OPIs) from kinematic event data. Our goal was to determine whether OPIs improve with surgeon experience and whether they are correlated with clinical outcomes for robotic inguinal hernia repair (RIHR).MethodsThe IDR was used to record RIHRs from six surgeons. Data were obtained from 98 inguinal hernia repairs from February 2022 to February 2023. Patients were called on postoperative days 5–10 and asked to take the Carolina Comfort Scale (CCS) survey to evaluate acute clinical outcomes. A Pearson test was run to determine correlations between OPIs from the IDR with a surgeon’s yearly RIHR experience and with CCS scores. Linear regression was then run for correlated OPIs.ResultsMultiple OPIs were correlated with surgeon experience. Specifically, for the task of peritoneal flap exploration, we found that 23 OPIs were significantly correlated with surgeons’ 1-year RIHR case number. Total angular motion distance of the left arm instrument had a correlation of − 0.238 (95% CI − 0.417, − 0.042) for RIHR yearly case number. Total angular motion distance of right arm instrument was also negatively correlated with RIHR in 1 year with a correlation of − 0.242 (95% CI − 0.420, − 0.046). For clinical outcomes, wrist articulation of the surgeon’s console positively correlated with acute sensation scores from the CCS with a correlation of 0.453 (95% CI 0.013, 0.746).ConclusionsThis study defines multiple OPIs that correlate with surgeon experience and with outcomes. Using this knowledge, surgical simulation platforms can be designed to teach patterns to surgical trainees that are associated with increased surgical experience and with improved postoperative outcomes.
Journal Article
Kinematic metrics and surgeon experience in robotic cholecystectomies: a pilot study on breaking down technical performance
by
Yee, Andrew
,
Andrews, Robert
,
Bitner, Daniel P
in
Cholecystectomy
,
Dissection
,
Robotic surgery
2024
BackgroundRecent studies have correlated surgical skill measured by video-based assessment with improved clinical outcomes. Certain automated measures of operative performance in robotic surgery can be gathered beyond video review called objective performance indicators (OPIs). We explore the relationship between OPIs, surgeon experience, and postoperative recovery, hypothesizing that more efficient dissection will be associated with experience.MethodsFifty-six robotic cholecystectomies between February 2022 and March 2023 were recorded at a large tertiary referral center. Surgeon experience and clinical outcomes data from the EMR were obtained for all 56 cases with 10 completing the QOL survey. Two steps of robotic cholecystectomies were reviewed: dissection of Calot's triangle (DCT) and dissection of the gallbladder from the liver (DGL). Postoperative recovery was measured using the SF-36 well-being survey. Univariate analysis was conducted using Pearson’s coefficient.ResultsIncreased operative experience was associated with more efficient camera and instrument movements. DCT had 7 and DGL had 31 of 41 OPIs that correlated with experience. With respect to DGL, more experienced surgeons had reduced step duration and instrument path length and increased camera and instrument speeds.ConclusionsSeveral OPIs correlate with surgical experience and may form the basis of more instructive feedback for trainees and less experienced surgeons in improving intraoperative technique.
Journal Article
Reactivity of a Carene-Derived Hydroxynitrate in Mixed Organic/Aqueous Matrices: Applying Synthetic Chemistry to Product Identification and Mechanistic Implications
by
LaLonde, Rebecca Lyn
,
McAlister, Addison B.
,
Bailey, Gabriela M.
in
3-Carene
,
Aerosols
,
Air pollution
2021
β-hydroxynitrates (HN) are a major class of products formed during OH and NO3 initiated oxidation of terpenes. Their production contributes significantly to secondary organic aerosol (SOA) formation and NOx sequestration. However, studying the condensed phase reactions of this important class of molecules has been hindered by the lack of commercially available authentic standards. The goal of this work was to examine the influence of water concentration and solvent identity on product yields of a tertiary HN derived from 3-carene prepared in house. To assess the role of water on conversion chemistry, bulk-phase reactions were conducted in DMSO-d6, a non-nucleophilic solvent, with a gradient of water concentrations, and analyzed with 1H NMR. Product identifications were made by comparison with authentic standards prepared in house. Four major products were identified, including an unexpected diol produced from carbocation rearrangement, diol diastereomers, and trans-3-carene oxide, with varying yields as a function of water concentration. Product yields were also measured in two protic, nucleophilic solvents, MeOD-d4 and EtOD-d6. Finally, reactions with added chloride formed alkyl chloride products in yields approaching 30%. These results are among the first to highlight the complexities of nucleophilic reactions of hydroxynitrates in bulk, mixed aqueous/organic media and to identify new, unexpected products.
Journal Article
Cerebral white matter rarefaction has both neurodegenerative and vascular causes and may primarily be a distal axonopathy
by
Beach, Thomas G
,
Sue, Lucia I
,
Scott, Sarah
in
Alzheimer Disease - diagnostic imaging
,
Alzheimer Disease - pathology
,
Alzheimer's disease
2023
Abstract
Cerebral white matter rarefaction (CWMR) was considered by Binswanger and Alzheimer to be due to cerebral arteriolosclerosis. Renewed attention came with CT and MR brain imaging, and neuropathological studies finding a high rate of CWMR in Alzheimer disease (AD). The relative contributions of cerebrovascular disease and AD to CWMR are still uncertain. In 1181 autopsies by the Arizona Study of Aging and Neurodegenerative Disorders (AZSAND), large-format brain sections were used to grade CWMR and determine its vascular and neurodegenerative correlates. Almost all neurodegenerative diseases had more severe CWMR than the normal control group. Multivariable logistic regression models indicated that Braak neurofibrillary stage was the strongest predictor of CWMR, with additional independently significant predictors including age, cortical and diencephalic lacunar and microinfarcts, body mass index, and female sex. It appears that while AD and cerebrovascular pathology may be additive in causing CWMR, both may be solely capable of this. The typical periventricular pattern suggests that CWMR is primarily a distal axonopathy caused by dysfunction of the cell bodies of long-association corticocortical projection neurons. A consequence of these findings is that CWMR should not be viewed simply as “small vessel disease” or as a pathognomonic indicator of vascular cognitive impairment or vascular dementia.
Journal Article
Characterization of Isolated Human Astrocytes from Aging Brain
2025
Astrocytes have multiple crucial roles, including maintaining brain homeostasis and synaptic function, performing phagocytic clearance, and responding to injury and repair. It has been suggested that astrocyte performance is progressively impaired with aging, leading to imbalances in the brain’s internal milieu that eventually impact neuronal function and lead to neurodegeneration. Until now, most evidence of astrocytic dysfunction in aging has come from experiments done with whole tissue homogenates, astrocytes collected by laser capture, or cell cultures derived from animal models or cell lines. In this study, we used postmortem-derived whole cells sorted with anti-GFAP antibodies to compare the unbiased, whole-transcriptomes of human astrocytes from control, older non-impaired individuals and subjects with different neurodegenerative diseases, such as Parkinson’s disease (PD), Alzheimer’s disease (ADD), and progressive supranuclear palsy (PSP). We found hundreds of dysregulated genes between disease and control astrocytes. In addition, we identified numerous genes shared between these common neurodegenerative disorders that are similarly dysregulated; in particular, UBC a gene for ubiquitin, which is a protein integral to cellular homeostasis and critically important in regulating function and outcomes of proteins under cellular stress, was upregulated in PSP, PD, and ADD when compared to control.
Journal Article
Beyond capacity: an EAST multicenter mixed-methods study exploring surgeon perceptions on patient ratios in acute care surgery
by
Knowlton, Lisa Marie
,
Holleman, Gerrit
,
Shayn Martin, R
in
Burnout
,
Critical care
,
Delivery of Health Care
2025
BackgroundOptimal provider-to-patient (PtP) ratios in acute care surgery (ACS) remain undefined despite their importance for care quality and provider sustainability. This study aimed to understand surgeon perspectives on maximum ideal ratios across trauma, emergency general surgery (EGS) and surgical intensive care unit (SICU) services.MethodsThis multicenter mixed-methods study combined quantitative surveys and semistructured interviews with ACS surgeons at level I/II trauma centers across the USA (1 August 2023–19 April 2024). Service line census data were also collected. Interviews were recorded, transcribed and qualitative analysis performed; surveys were analyzed with descriptive statistics.ResultsFifty-two interviews were completed. Survey response rate was 50.3% (212/421 eligible division leadership and faculty) from 40 centers across 24 states. The perceived maximum safe patient load for trauma and EGS was <20 patients when working independently, and up to 40 patients with full team support. SICU ratios were lower with most reporting ≤10 patients for independent coverage and ≤20 with team support. Regarding appropriate patient loads for junior residents and advanced practice providers, most respondents recommended ≤10 patients for trauma/EGS and ≤7 for SICU. For senior residents, most recommended ≤13 patients for trauma/EGS and ≤7 for SICU. Notably, 72% of centers exceeded their own leadership-recommended maximums for at least one service line. Qualitative analysis revealed patient acuity, team experience and competing demands as key workload modulators, with concerns about care quality degradation and burnout at higher ratios.ConclusionsThis study establishes potential upper threshold benchmarks for ACS PtP ratios with strong agreement across institutions. Division leadership should consider developing staffing models that account for patient acuity and service complexity while implementing escalation protocols for sustained high workloads. Current practices frequently exceed maximum ideal ratios, highlighting the need for evidence-based staffing guidelines that balance financial constraints with mounting evidence linking workload intensity and density to adverse outcomes.Level of evidenceIV.
Journal Article