Guy Albert Dumont

Guy Albert Dumont
University of British Columbia - Vancouver | UBC · Department of Electrical and Computer Engineering

PhD

About

658
Publications
108,542
Reads
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11,308
Citations
Citations since 2017
111 Research Items
5034 Citations
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Additional affiliations
July 1989 - present
Columbia University
Position
  • Professor (Full)
July 1983 - present
University of British Columbia - Vancouver

Publications

Publications (658)
Article
Stethoscope-recorded chest sounds provide the opportunity for remote cardio-respiratory health monitoring of neonates. However, reliable monitoring requires high-quality heart and lung sounds. This paper presents novel artificial intelligence-based Non-negative Matrix Factorisation (NMF) and Non-negative Matrix Co-Factorisation (NMCF) methods for n...
Article
In response to: Spurr R, Ng E, Onchiri FM, Rapha B, Nakatumba‐Nabende J, Rosenfeld M, Najjingo I, Stout J, Nantanda R, Ellington LE. Performance and usability of a new mobile application for measuring respiratory rate in young children with acute lower respiratory infections. Pediatr Pulmonol. 2022 Aug 22. doi: 10.1002/ppul.26125 This article is pr...
Preprint
In response to: Spurr R, Ng E, Onchiri FM, Rapha B, Nakatumba-Nabende J, Rosenfeld M, Najjingo I, Stout J, Nantanda R, Ellington LE. Performance and usability of a new mobile application for measuring respiratory rate in young children with acute lower respiratory infections. Pediatr Pulmonol. 2022 Aug 22. doi: 10.1002/ppul.26125.
Article
Full-text available
Introduction Treatment options for ADHD in adults consist of psycho-education, cognitive behavioral therapy (CBT), pharmacotherapy or a combination thereof. Current studies do not yet provide insights into the additive effects of CBT and pharmacotherapy regarding the quality of life in adults with ADHD. Objectives In this study, we investigated th...
Conference Paper
Neonatal respiratory distress is a common condition that if left untreated, can lead to short- and long-term complications. This paper investigates the usage of digital stethoscope recorded chest sounds taken within 1 min post-delivery, to enable early detection and prediction of neonatal respiratory distress. Fifty-one term newborns were included...
Article
Full-text available
Background: Iron-deficiency anemia is a known risk factor for several adverse perinatal outcomes, but data on its impact on specific maternal morbidities is less robust. Further, information on associations between anemia in early pregnancy and subsequent outcomes are understudied. Methods: The study population was derived from the Community Lev...
Preprint
Full-text available
Neonatal respiratory distress is a common condition that if left untreated, can lead to short- and long-term complications. This paper investigates the usage of digital stethoscope recorded chest sounds taken within 1min post-delivery, to enable early detection and prediction of neonatal respiratory distress. Fifty-one term newborns were included i...
Preprint
Full-text available
Stethoscope-recorded chest sounds provide the opportunity for remote cardio-respiratory health monitoring of neonates. However, reliable monitoring requires high-quality heart and lung sounds. This paper presents novel Non-negative Matrix Factorisation (NMF) and Non-negative Matrix Co-Factorisation (NMCF) methods for neonatal chest sound separation...
Article
In this study, a new method is proposed to assess heart and lung signal quality objectively and automatically on a 5-level scale in real-time, and to assess the effect of signal quality on vital sign estimation. A total of 207 10 s long chest sounds were taken from 119 preterm and full-term babies. Thirty of the recordings from ten subjects were ob...
Conference Paper
Full-text available
Obtaining high quality heart and lung sounds enables clinicians to accurately assess a newborns cardio-respiratory health and provide timely care. However, noisy chest sound recordings are common, hindering timely and accurate assessment. A new Non-negative Matrix Co-Factorisation based approach is proposed to separate noisy chest sound recordings...
Article
Presents a profile of Guy A. Dumont.
Article
Full-text available
Objective. Investigation of the night-to-night (NtN) variability of pulse oximetry features in children with suspicion of Sleep Apnea.Approach. Following ethics approval and informed consent, 75 children referred to British Columbia Children's Hospital for overnight PSG were recorded on three consecutive nights, including one at the hospital simult...
Preprint
Full-text available
Digital stethoscopes in combination with telehealth allow chest sounds to be easily collected and transmitted for remote monitoring and diagnosis. Chest sounds contain important information about a newborn's cardio-respiratory health. However, low-quality recordings complicate the remote monitoring and diagnosis. In this study, a new method is prop...
Preprint
Full-text available
The COVID-19 pandemic has had an enormous toll on human health and well-being and led to major social and economic disruptions. Public health interventions in response to burgeoning case numbers and hospitalizations have repeatedly bent down the epidemic curve in many jurisdictions, effectively creating a closed-loop dynamic system. We aim to forma...
Preprint
Full-text available
Obtaining high-quality heart and lung sounds enables clinicians to accurately assess a newborn's cardio-respiratory health and provide timely care. However, noisy chest sound recordings are common, hindering timely and accurate assessment. A new Non-negative Matrix Co-Factorisation-based approach is proposed to separate noisy chest sound recordings...
Article
Full-text available
Background Blood pressure measurement is a marker of antenatal care quality. In well resourced settings, lower blood pressure cutoffs for hypertension are associated with adverse pregnancy outcomes. We aimed to study the associations between blood pressure thresholds and adverse outcomes and the diagnostic test properties of these blood pressure cu...
Article
Full-text available
Background Incomplete vital registration systems mean that causes of death during pregnancy and childbirth are poorly understood in low-income and middle-income countries. To inform global efforts to reduce maternal mortality, we compared physician review and computerised analysis of verbal autopsies (interpreting verbal autopsies [InterVA] softwar...
Article
Full-text available
Dose-dependent effects of ketamine on processed electroencephalographic depth-of-hypnosis indices have been reported. Limited data are available for the NeuroSENSE WAVCNS index. Our aim was to establish the feasibility of closed-loop propofol-remifentanil anesthesia guided by the WAVCNS index in the presence of an analgesic dose of ketamine. Thirty...
Article
Full-text available
In pregnancy in well-resourced settings, limited data suggest that higher blood pressure (BP) visit-to-visit variability may be associated with adverse pregnancy outcomes. Included were pregnant women in 22 intervention clusters of the CLIP (Community-Level Interventions for Preeclampsia) cluster randomized trials, who had received at least 2 prena...
Article
Background: Closed-loop control of propofol-remifentanil anesthesia using the processed electroencephalography depth-of-hypnosis index provided by the NeuroSENSE monitor (WAVCNS) has been previously described. The purpose of this placebo-controlled study was to evaluate the performance (percentage time within ±10 units of the setpoint during the m...
Article
This paper presents a two-component framework to detect model-plant mismatch (MPM) in cross-directional (CD) processes on paper machines under model-predictive control. First, routine operating data is used for system identification in closed loop; second, a one-class support vector machine (SVM) is trained to predict MPM. The iterative identificat...
Article
Background: Treatment options for attention deficit hyperactivity disorder (ADHD) in adults consist of psycho-education, cognitive behavioral therapy (CBT), pharmacotherapy or a combination thereof. Aim: To investigate the effect of CBT combined with pharmacotherapy on the quality of life in adults with ADHD compared to medication alone. Method...
Article
In the TRIUMF electron linear accelerator (e-linac), electron beams are injected into cavity resonators and accelerated to energies up to 50 MeV. The control goal is to maintain constant accelerating field inside the cavity resonators. As a result of energy transfer from the field to the beam, cavity voltage is reduced. In this work, we aim to use...
Article
With advances in digital stethoscopes, internet of things, signal processing and machine learning, chest sounds can be easily collected and transmitted to the cloud for remote monitoring and diagnosis. However, low quality of recordings complicates remote monitoring and diagnosis, particularly for neonatal care. This paper proposes a new method to...
Article
Full-text available
A framework using semidefinite programming is proposed to enable the design of sigma delta modulator loop filters at the transfer function level. Both continuous-time and discrete-time, low-pass and band-pass designs are supported. For performance, we use the recently popularized Generalized Kalman–Yakubovič–Popov (GKYP) lemma to place constraints...
Article
This paper studies application of different constrained control concepts for the control of Depth of Hypnosis (DOH) in closed-loop anesthesia to guarantee patient safety, while ensuring acceptable tracking performance. The core idea is to formulate Overdosing (OD) prevention and Blood Pressure Decrease (BPD) prevention as operational constraints, a...
Article
Objective Monitoring of the ultra-low frequency potentials, particularly cortical spreading depression (CSD), is excluded in epilepsy monitoring due to technical barriers imposed by the scalp ultra-low frequency electroencephalogram (EEG). As a result, clinical studies of CSD have been limited to invasive EEG. Therefore, the occurrence of CSD and...
Article
Full-text available
Background and Objective: New proposals to improve the regulation of hypnosis in anaesthesia based on the development of advanced control structures emerge continuously. However, a fair study to analyse the real benefits of these structures compared to simpler clinically validated PID-based solutions has not been presented so far. The main objectiv...
Article
Full-text available
Background To overcome the three delays in triage, transport and treatment that underlie adverse pregnancy outcomes, we aimed to reduce all-cause adverse outcomes with community-level interventions targeting women with pregnancy hypertension in three low-income countries. Methods In this individual participant-level meta-analysis, we de-identified...
Article
Full-text available
Background: Sepsis is the leading cause of death and disability in children. Every hour of delay in treatment is associated with an escalating risk of morbidity and mortality. The burden of sepsis is greatest in low- and middle-income countries where timely treatment may not occur due to delays in diagnosis and prioritization of critically ill chi...
Article
Around the globe, epidemiologists, statisticians, biologists, and health officials are grappling with these questions. Though engineering perspectives are uncommon in epidemiological modeling, we believe that in this case public officials could greatly benefit from one. Of course, the COVID-19 pandemic isn't an obvious or typical engineering proble...
Conference Paper
Full-text available
Closed-loop controlled drug dosing has the potential of revolutionizing clinical anesthesia. However, inter-patient variability in drug sensitivity poses a central challenge to the synthesis of safe controllers. Identifying a full individual pharmacokinetic-pharmacodynamic (PKPD) model for this synthesis is clinically infeasible due to limited exci...
Article
Background and Objective: Intraoperative hemodynamic stability is essential to safety and post-operative well-being of patients and should be optimized in closed-loop control of anesthesia. Cardiovascular changes inducing variations in pharmacokinetics may require dose modification. Rigorous investigational tools can strengthen current knowledge of...
Article
This paper proposes a model predictive control (MPC) solution for closed-loop propofol and remifentanil infusion based on feedback from a depth-of-hypnosis monitor, a multi-input single-output system. A clinically relevant objective function is proposed, extending the habituating MPC solution. The presented MPC controller meets the following clinic...
Article
Sugammadex, a specific reversal agent for steroidal neuromuscular blocking drugs, has on occasion been reported to be associated with clinical signs of awakening. We performed a study to systematically search for an increase in bispectral index values and signs of awakening in patients maintained under general anaesthesia following sugammadex admin...
Article
Purpose Processed electroencephalography (EEG) monitors support depth-of-hypnosis assessment during anesthesia. This randomized-controlled trial investigated the performance of the NeuroSENSE electroencephalography (EEG) monitor to determine whether its wavelet anesthetic value for central nervous system (WAVCNS) index distinguishes consciousness f...
Article
We develop a model-plant mismatch (MPM) detection strategy based on a novel closed-loop identification approach and one-class support vector machine (SVM) learning technique. With this scheme we can monitor MPM and noise model change separately, thus separating the MPM from noise model changes. Another advantage of this approach is that it is appli...
Article
This brief proposes a constrained control scheme for the control of the depth of hypnosis during the induction phase in clinical anesthesia. In contrast with the existing control schemes for propofol delivery, the proposed scheme guarantees overdosing prevention while ensuring good dynamic performance. The core idea is to reformulate overdosing pre...
Poster
Full-text available
Introduction: Closed-loop control of propofol-remifentanil anesthesia using the WAVCNS depth-of-hypnosis index (NeuroSENSE NS-701, v2.0.0.3, NeuroWave Systems Inc, Cleveland, OH) is clinically feasible in adult patients undergoing general anesthesia for elective surgery [1]. Ketamine, frequently used as a component of a multimodal intraoperative re...
Article
Despite advances in the treatment of acute spinal cord injury (SCI), measures to mitigate permanent neurological deficits in affected patients are limited. Immediate post-trauma hemodynamic management of patients, to maintain blood supply and improve oxygenation to the injured spinal cord, is currently one aspect of critical care which clinicians c...
Article
We propose a maximum likelihood estimation approach for the identification of symmetric noncausal models. Such models are used to represent the cross-directional dynamic response of many industrial processes that are generally modeled with a high-dimensional gain matrix. Reducing the number of parameters in a noncausal model can significantly reduc...
Article
Discussion of safety preserving control in the presence of uncertainty has mostly focused on stochastic and additive uncertainty. Multiplicative uncertainty can be represented as additive uncertainty, however, this may lead to very conservative solutions. We recently introduced a model-invariant safety-preserving control scheme for multiplicative u...
Article
Closed-loop anesthesia drug delivery systems can reduce the effect of inter-patient variability, minimize variability in desired clinical effects, and ultimately improve patient safety. Feasibility of closed-loop anesthesia has been clinically evaluated in a number of studies. To obtain regulatory approval to use closed-loop anesthesia as a clinica...
Article
Full-text available
In this study, we further investigate electroencephalographic (EEG) data recorded during October 2014 in the ultra-shielded capsule at LSBB, with a focus on the study of task-specific Granger-causal effective connectivity pat-terns. In previous studies, we showed that noise-free EEG signals acquired in LSBB are suitable for analysis of activity pat...
Article
Full-text available
Objective: The goal of this paper was to optimize robust PID control for propofol anesthesia in children aged 5-10 years to improve performance, particularly to decrease the time of induction of anesthesia while maintaining robustness. Methods: We analyzed results of a previous study conducted by our group to identify opportunities for system im...
Article
This paper presents a semi-adaptive closed-loop control approach to autonomous infusion of medications exhibiting significant transport delay in clinical effects. The basic idea of the approach is to enable stable adaptive control of medication infusion by (1) incorporating transport delay explicitly into control design by way of a Padé approximati...
Poster
Full-text available
Background: Processed electroencephalography (EEG) monitors support depth of hypnosis assessment during anesthesia [1,2]. This randomized study investigated the performance of the NeuroSENSE EEG monitor (NeuroWave Systems Inc., Cleveland Heights, OH) to determine how well its WAVCNS index [3] distinguishes consciousness from unconsciousness during...
Article
Full-text available
Sedation in the intensive care unit (ICU) is challenging, as both over- and under-sedation are detrimental. Current methods of assessment, such as the Richmond Agitation Sedation Scale (RASS), are measured intermittently and rely on patients’ behavioral response to stimulation, which may interrupt sleep/rest. A non-stimulating method for continuous...
Preprint
This paper proposes a constrained control scheme for the control of the depth of hypnosis during induction phase in clinical anesthesia. In contrast with existing control schemes for propofol delivery, the proposed scheme guarantees overdosing prevention while ensuring good performance. The core idea is to reformulate overdosing prevention as a con...
Article
This brief introduces a novel safety-preserving control scheme with minimal conservatism for uncertain systems. We have recently introduced the model-invariant safety verification technique that provides a formal guarantee of safety for systems with multiplicative model uncertainty. This approach requires a multi-model description of model uncertai...
Conference Paper
Background: Increasing accessibility to diagnostic resources would enable early detection of obstructive sleep apnea syndrome (OSAS) in children. Portable oximetry and automated signal processing techniques could speed up diagnosis. Aims and objectives: To assess symbolic dynamics as a reliable technique to characterize complex fluctuations of por...
Article
Objective: This study is aimed at assessing symbolic dynamics as a reliable technique to characterise complex fluctuations of portable oximetry in the context of automated detection of childhood obstructive sleep apnoea-hypopnoea syndrome (OSAHS). Approach: Nocturnal oximetry signals from 142 children with suspected OSAHS were acquired using the...
Article
Feasibility of closed-loop propofol anesthesia has been demonstrated in clinical trials; however, no closed-loop system is currently routinely used in clinical practice. Data from closed-loop clinical trials provide valuable information for system evaluation prior to market approval, including outlier behavior. To exploit this valuable data, closed...
Article
Background and aim: Telehealth is a strategy to expand the reach of pulmonary rehabilitation (PR). Smartphones can monitor and transmit oxygen saturation (SpO2) and heart rate (HR) data to ensure patient safety during home-based or other exercise. The purpose of this study was to evaluate the usability, validity and reliability of a Kenek O2 pulse...
Article
Background: Assessments of pediatric obstructive sleep apnea (OSA) are underutilized across Canada due to a lack of resources. Polysomnography (PSG) measures OSA severity through the average number of apnea/hypopnea events per hour (AHI), but is resource intensive and requires a specialized sleep laboratory, which results in long waitlists and del...
Conference Paper
Obstructive Sleep Apnea (OSA) is the most common form of sleep-disordered breathing in children. The gold standard to screen for OSA, polysomnography (PSG), requires an overnight stay in the hospital and is resource intensive. The Phone Oximeter is a non-invasive smartphone-based tool to record pulse oximetry. This portable device is able to measur...
Poster
Today almost 6 billion people around the world live in countries where access to adequate medical care resources and facilities is limited. Portable optical technologies can potentially improve health care delivery in emerging countries. Medical optical devices can non-invasively determine the composition of tissue and their function, as well as be...
Article
Full-text available
In this study, we proposed a novel method for extracting the instantaneous respiratory rate (IRR) from the pulse oximeter photoplethysmogram (PPG). The method was performed in three main steps: (1) a time-frequency transform called synchrosqueezing transform (SST) was used to extract the respiratory-induced intensity, amplitude and frequency variat...
Article
Full-text available
This work provides a formalized model-invariant safety system for closed-loop anesthesia that uses feedback from measured data for model falsification to reduce conservatism. The safety system maintains predicted propofol plasma concentrations, as well as the patient's blood pressure, within safety bounds despite uncertainty in patient responses to...
Article
Full-text available
The pediatric intensive care unit (ICU) is a complex environment, in which a multidisciplinary team of clinicians (registered nurses, respiratory therapists, and physicians) continually observe and evaluate patient information. Data are provided by multiple, and often physically separated sources, cognitive workload is high, and team communication...