32 research outputs found
Egocentric Perception using a Biologically Inspired Software Retina Integrated with a Deep CNN
We presented the concept of of a software retina, capable
of significant visual data reduction in combination with
scale and rotation invariance, for applications in egocentric
and robot vision at the first EPIC workshop in Amsterdam
[9]. Our method is based on the mammalian retino-cortical
transform: a mapping between a pseudo-randomly tessellated
retina model (used to sample an input image) and a
CNN. The aim of this first pilot study is to demonstrate a
functional retina-integrated CNN implementation and this
produced the following results: a network using the full
retino-cortical transform yielded an F1 score of 0.80 on a
test set during a 4-way classification task, while an identical
network not using the proposed method yielded an F1
score of 0.86 on the same task. On a 40K node retina the
method reduced the visual data bye×7, the input data to the
CNN by 40% and the number of CNN training epochs by
36%. These results demonstrate the viability of our method
and hint at the potential of exploiting functional traits of
natural vision systems in CNNs. In addition, to the above
study, we present further recent developments in porting
the retina to an Apple iPhone, an implementation in CUDA
C for NVIDIA GPU platforms and extensions of the retina
model we have adopted
A Pilot Study To Determine the Incidence, Type, and Severity of Non-Routine Events in Neonates Undergoing Gastrostomy Tube Placement
BACKGROUND: Non-routine events (NRE) are defined as any suboptimal occurrences in a process being measured in the opinion of the reporter and comes from the field of human factors engineering. These typically occur well up-stream of an adverse event and NRE measurement has not been applied to the complex context of neonatal surgery. We sought to apply this novel safety event measurement methodology to neonates in the NICU undergoing gastrostomy tube placement.
METHODS: A prospective pilot study was conducted between November 2016 and August 2020 in the Level IV NICU and the pediatric operating rooms of an urban academic children\u27s hospital to determine the incidence, severity, impact, and contributory factors of clinician-reported non-routine events (NREs, i.e., deviations from optimal care) and 30-day NSQIP occurrences in neonates receiving a G-tube.
RESULTS: Clinicians reported at least one NRE in 32 of 36 (89%) G-tube cases, averaging 3.0 (Standard deviation: 2.5) NRE reports per case. NSQIP-P review identified 7 cases (19%) with NSQIP-P occurrences and each of these cases had multiple reported NREs. One case in which NREs were not reported was without NSQIP-P occurrences. The odds ratio of having a NSQIP-P occurrence with the presence of an NRE was 0.695 (95% CI 0.06-17.04).
CONCLUSION: Despite being considered a simple operation, \u3e80% of neonatal G-tube placement operations had at least one reported NRE by an operative team member. In this pilot study, NRE occurrence was not significantly associated with the subsequent reporting of an NSQIP-P occurrence. Understanding contributory factors of NREs that occur in neonatal surgery may promote surgical safety efforts and should be evaluated in larger and more diverse populations.
LEVEL OF EVIDENCE: IV
Defining the Epidemiology of Safety Risks in Neonatal Intensive Care Unit Patients Requiring Surgery
OBJECTIVE: The aim of the study was to determine the incidence, type, severity, preventability, and contributing factors of nonroutine events (NREs)-events perceived by care providers or skilled observers as a deviations from optimal care based on the clinical situation-in the perioperative (i.e., preoperative, operative, and postoperative) care of surgical neonates in the neonatal intensive care unit and operating room.
METHODS: A prospective observational study of noncardiac surgical neonates, who received preoperative and postoperative neonatal intensive care unit care, was conducted at an urban academic children\u27s hospital between November 1, 2016, and March 31, 2018. One hundred twenty-nine surgical cases in 109 neonates were observed. The incidence and description of NREs were collected via structured researcher-administered survey tool of involved clinicians. Primary measurements included clinicians\u27 ratings of NRE severity and contributory factors and trained research assistants\u27 ratings of preventability.
RESULTS: One or more NREs were reported in 101 (78%) of 129 observed cases for 247 total NREs. Clinicians reported 2 (2) (median, interquartile range) NREs per NRE case with a maximum severity of 3 (1) (possible range = 1-5). Trained research assistants rated 47% of NREs as preventable and 11% as severe and preventable. The relative risks for National Surgical Quality Improvement Program - pediatric major morbidity and 30-day mortality were 1.17 (95% confidence interval = 0.92-1.48) and 1.04 (95% confidence interval = 1.00-1.08) in NRE cases versus non-NRE cases.
CONCLUSIONS: The incidence of NREs in neonatal perioperative care at an academic children\u27s hospital was high and of variable severity with a myriad of contributory factors
An endogenous circadian rhythm of respiratory control in humans
Many physiological and behavioural functions have circadian rhythms – endogenous oscillations with a period of approximately 24 h that can occur even in the absence of sleep. We determined whether there is an endogenous circadian rhythm in breathing, metabolism and ventilatory chemosensitivity in humans.Ten healthy, adult males were studied throughout 4 days in a stable laboratory environment. After two initial baseline days (16 h wakefulness plus 8 h sleep) that served to achieve a steady state, subjects were studied under constant behavioural and environmental conditions throughout 41 h of wakefulness. Ventilation, metabolism and the magnitude of the hypercapnic ventilatory response (HCVR) were measured every 2 h. Individuals’ data were aligned according to circadian phase (core body temperature minimum; CBTmin) and averaged.In the group average data, there was a significant and large amplitude circadian variation in HCVR slope (average of ±0.4 l min−1 mmHg−1; corresponding to ±12.1 % of 24 h mean), and a smaller amplitude rhythm in the HCVR x-axis intercept (average of ±1.1 mmHg; ±2.1 % of 24 h mean).Despite a significant circadian variation in metabolism (±3.2 % of 24 h mean), there were no detectable rhythms in tidal volume, respiratory frequency or ventilation. This small discrepancy between metabolism and ventilation led to a small but significant circadian variation in end-tidal PCO2(PET,CO2; ±0.6 mmHg; ±1.5 % of 24 h mean).The circadian minima of the group-averaged respiratory variables occurred 6-8 h earlier than CBTmin, suggesting that endogenous changes in CBT across the circadian cycle have less of an effect on respiration than equivalent experimentally induced changes in CBT.Throughout these circadian changes, there were no correlations between HCVR parameters (slope or x-axis intercept) and either resting ventilation or resting PET,CO2. This suggests that ventilation and PET,CO2 are little influenced by central chemosensory respiratory control in awake humans even when at rest under constant environmental and behavioural conditions.The characteristic change in PET,CO2 during non-rapid eye movement sleep was shown to be independent of circadian variations in PET,CO2, and probably reflects a change from predominantly behavioural to predominantly chemosensory respiratory control.This study has documented the existence and magnitude of circadian variations in respiration and respiratory control in awake humans for the first time under constant behavioural and environmental conditions. These results provide unique insights into respiratory control in awake humans, and highlight the importance of considering the phase of the circadian cycle in studies of respiratory control