Natalie Baddour

Natalie Baddour
University of Ottawa · Department of Mechanical Engineering

PhD University of Toronto

About

187
Publications
114,201
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,605
Citations
Introduction
I hold a Bachelor of Science degree from Memorial University of Newfoundland, a Master of Mathematics degree from the University of Waterloo and a Ph.D. in Mechanical Engineering from the University of Toronto (Canada). I spent some time as a post-doc at both the University of Toronto and also at the University of Bath (U.K) as a Chevening Fellow. I am now professor and department chair at the Department of Mechanical Engineering, University of Ottawa, Canada. I am also the Principal Investigator the Natural Sciences and Engineering Research Council of Canada CREATE grant titled "Biomedical Engineering Smartphone Training" -- see www.create-best.ca.
Additional affiliations
May 2017 - present
University of Ottawa
Position
  • Professor (Full)
May 2010 - May 2017
University of Ottawa
Position
  • Professor (Associate)
December 2005 - May 2010
University of Ottawa
Position
  • Professor (Assistant)

Publications

Publications (187)
Article
Full-text available
Human posture and range of motion (ROM) measurements are important health indicators for identifying abnormalities from various disorders (e.g., scoliosis, musculoskeletal disorders, pain syndromes). A viable real-time mobile application for measuring body posture and ROM is currently lacking. To address this need, a novel Android smartphone augmen...
Article
Full-text available
The 6-min walk test (6MWT) is commonly used to assess a person's physical mobility and aerobic capacity. However, richer knowledge can be extracted from movement assessments using artificial intelligence (AI) models, such as fall risk status. The 2-min walk test (2MWT) is an alternate assessment for people with reduced mobility who cannot complete...
Article
Full-text available
The presence of a crack in a beam leads to changes in its dynamic characteristics and hence changes in its natural frequencies and mode shapes. In this paper, Alternative Admissible Functions (AAF) with penalties for extracting the dynamic characteristics of a Euler–Bernoulli Beam with a shallow crack is proposed and validated. The proposed method...
Article
Full-text available
New artificial intelligence- (AI) based marker-less motion capture models provide a basis for quantitative movement analysis within healthcare and eldercare institutions, increasing clinician access to quantitative movement data and improving decision making. This research modelled, simulated, designed, and implemented a novel marker-less AI motion...
Article
Full-text available
Foot strike detection is important when evaluating a person’s gait characteristics. Accelerometer and gyroscope signals from smartphones have been used to train artificial intelligence (AI) models for automated foot strike detection in able-bodied and elderly populations. However, there is limited research on foot strike detection in lower limb amp...
Article
This paper proposes an adaptive nylon flywheel, which can achieve passive vibration control by generating variable equivalent mass. With changing rotational speed, the location of sliders in the slots changes, which leads to the creation of variable equivalent mass. Due to the light weight and high strength of the nylon material, a higher changing...
Article
Background: Although the global population of people with a hip disarticulation (HD) or hemipelvectomy (HP) amputation is small, the degree of disability is high, affecting function and independence. A comprehensive literature review is needed to examine the evidence for prostheses in these amputation levels. Method: A scoping literature review...
Conference Paper
Full-text available
Assumed mode methods are often used in vibrations analysis, where the choice of assumed mode affects the stability and useability of the method. System eigenfunctions are often used for these expansions, however, a change in the boundary conditions usually results in a change in eigenfunction. This paper investigates the use of Alternative Admissib...
Article
Full-text available
Fall-risk classification is a challenging but necessary task to enable the recommendation of preventative programs for individuals identified at risk for falling. Existing research has primarily focused on older adults, with no predictive fall-risk models for lower limb amputees, despite their greater likelihood of fall-risk than older adults. In t...
Article
This article presents a new stress model for EB-PVD TBC to provide insight into TBC failure mechanisms. Cycling-induced and temperature-process dependent model parameters are incorporated into stress analysis of EB-PVD TBC and then used to simulate the variation of mechanical, thermal and inelastic behaviour from metallic bond coat to thermally gro...
Article
Full-text available
Objective: In this research, a marker-less 'smart hallway' is proposed where stride parameters are computed as a person walks through an institutional hallway. Stride analysis is a viable tool for identifying mobility changes, classifying abnormal gait, estimating fall risk, monitoring progression of rehabilitation programs, and indicating progres...
Article
Full-text available
Residual stresses play an essential role in determining the failure mechanisms and life of an electron beam-physical vapour deposition thermal barrier coating (EB-PVD TBC) system. In this paper, a new transitional roughness model was proposed and applied to describe the interfacial roughness profile during thermal cycles. Finite element models were...
Article
Full-text available
Recognizing aggressive movements is a challenging task in human activity recognition. Wearable smartwatch technology with machine learning may be a viable approach for human aggressive behavior classification. This research identified a viable classification model and feature selector (CM-FS) combination for separating aggressive from non-aggressiv...
Conference Paper
Ankle foot orthosis (AFO) stiffness affects ankle range of motion but can also provide energy storage and return to improve mobility. To perform multiple activities during the day, a person may want to change their AFO stiffness to meet their activity's demand. Carrying multiple AFOs and changing AFOs is inconvenient and could discourage users from...
Conference Paper
Marker tracking for postural and range of motion (ROM) measurements transcends multiple disciplines (e.g., healthcare, ergonomics, engineering). A viable real-time mobile application is currently lacking for measuring limb angles and body posture. To address this need, a novel Android smartphone augmented-reality-based application was developed usi...
Conference Paper
Identifying people at risk of falling can prevent life altering injury. Existing research has demonstrated fall-risk classifier effectiveness in older adults from accelerometer-based data. The amputee population should similarly benefit from these classification techniques; however, validation is still required. 83 individuals with varying levels o...
Article
Full-text available
The theory of the continuous two-dimensional (2D) Fourier Transform in polar coordinates has been recently developed but no discrete counterpart exists to date. In the first part of this two-paper series, we proposed and evaluated the theory of the 2D Discrete Fourier Transform (DFT) in polar coordinates. The theory of the actual manipulated quanti...
Article
A new adaptive nylon flywheel is proposed, which can achieve passive vibration control by generating variable equivalent mass. With changing rotational speed, the location of sliders in the slots changes, which leads to the creation of variable equivalent mass. Due to the light weight and high strength of the nylon material, a higher changing ratio...
Thesis
Full-text available
Many people with a lower extremity amputation have problems with stability when walking. These difficulties can result in activity avoidance, stumbles or falls, and lower quality of life. When analyzing amputee mobility, proper foot strike (FS) labelling can be problematic due to irregular gait patterns and asymmetries. This project explored FS ide...
Article
Full-text available
The theory of the continuous two-dimensional (2D) Fourier transform in polar coordinates has been recently developed but no discrete counterpart exists to date. In this paper, we propose and evaluate the theory of the 2D discrete Fourier transform (DFT) in polar coordinates. This discrete theory is shown to arise from discretization schemes that ha...
Article
Purpose: This research compares gait strategies to maintain stable gait over a variety of non-level walking conditions for individuals with a transtibial amputation and able-bodied individuals. Methods: Twelve people with unilateral transtibial amputation and twelve able-bodied individuals walked on a self-paced treadmill in a park-like virtual env...
Preprint
Full-text available
The theory of the continuous two-dimensional (2D) Fourier Transform in polar coordinates has been recently developed but no discrete counterpart exists to date. In the first part of this two-paper series, we proposed and evaluated the theory of the 2D discrete Fourier Transform (DFT) in polar coordinates. The theory of the actual manipulated quanti...
Preprint
The theory of the continuous two-dimensional (2D) Fourier Transform in polar coordinates has been recently developed but no discrete counterpart exists to date. In this paper, we propose and evaluate the theory of the 2D discrete Fourier Transform (DFT) in polar coordinates. This discrete theory is shown to arise from discretization schemes that ha...
Conference Paper
Full-text available
Distracted navigation causes 20% of all powered wheelchair accidents. In social situations, wheelchair users must divide their attention between navigating the chair and conversing with an accompanying person. These conversations could lead to increased mental stress and distractions from maneuvering the chair. This project aims to eliminate the ne...
Article
Full-text available
Vibration signal analysis is an important technique for bearing fault diagnosis. For bearings operating under constant rotational speed, faults can be diagnosed in the frequency domain since each type of fault has a specific Fault Characteristic Frequency (FCF), which is proportional to the shaft rotational speed. However, bearings often operate un...
Presentation
A conference presentation about the paper titled "Multiple depth sensor setup and synchronization for marker-less 3D human foot tracking in a hallway". Presentation slides are available at: http://seh2019.icmc.usp.br/presentations/SEH-14.pdf
Conference Paper
In this research, an animation was designed to determine an appropriate physical setup for depth sensors in an institutional hallway, for human foot surface capture and tracking. The sensor configuration was tested by creating the setup in a laboratory with Intel RealSense D415 depth cameras, synchronizing multiple depth sensors (spatially and temp...
Conference Paper
Full-text available
The ability of depth cameras like Kinect to capture a scene's depth information in three-dimensions, along with 2D color RGB images, in real-time makes marker-less human motion capture a potential option for applications such as rehabilitation, robotics, education, etc. Various depth sensor technologies are commercially available, and selecting the...
Article
Full-text available
Recent developments in photoacoustics have witnessed the implementation of a radar matched-filtering methodology into the continuous wave photoacoustic modality. The main merit of using matched filtering in continuous photoacoustics is the improvement in signal to noise ratio (SNR), but the correlation process may result in a loss of resolution. It...
Conference Paper
Full-text available
Stance-control knee-ankle-foot orthoses (SCKAFO) permit free knee motion during swing and knee flexion resistance during stance for individuals with knee-extensor muscle weakness. Microprocessor-controlled SCKAFO use electronic sensors and control algorithms to dictate when knee flexion resistance engages or disengages. Many SCKAFO require full leg...
Chapter
Full-text available
Appropriately positioning the Nipple-Areola Complex (NAC) during chest masculinization surgery is a principle determinant of the aesthetic success of the procedure. Nonetheless, today, this positioning process relies on the subjective judgement of the surgeon. Therefore, this paper proposes a novel machine learning solution that leverages Artificia...
Article
Using experimentally measured temperature-process-dependent model parameters, the failure analysis and life evaluation were conducted for electron beam-physical vapor deposition thermal barrier coatings (EB-PVD TBCs)with Pt-modified β-NiAl bond coats deposited on Ni-base single crystal superalloys. The failure analysis and life model were applied t...
Chapter
Full-text available
Article
Full-text available
Thermal conductivity of porous thermal barrier coatings was evaluated using a newly developed five-phase model. It was demonstrated that porosities distributed in coating strongly affect thermal conductivity. The decisive reason for this change in thermal conductivity can be traced back to defect morphology and its orientation, depending on the coa...
Article
Full-text available
Background Functionality and versatility of microprocessor-controlled stance-control knee-ankle-foot orthoses (M-SCKAFO) are dictated by their embedded control systems. Proper gait phase recognition (GPR) is required to enable these devices to provide sufficient knee-control at the appropriate time, thereby reducing the incidence of knee-collapse a...
Article
Full-text available
In social situations, people who use a powered wheelchair must divide their attention between navigating the chair and conversing with people. These conversations could lead to increased mental stress when navigating and distraction from maneuvering the chair. As a solution that maintains a good conversation distance between the wheelchair and the...
Article
Many approaches to elastography incorporate shear waves; in some systems these are produced by acoustic radiation force (ARF) push pulses. Understanding the shape and decay of propagating shear waves in lossy tissues is key to obtaining accurate estimates of tissue properties, and so analytical models have been proposed. In this paper, we reconside...
Article
Accurately evaluating the gear mesh stiffness with tooth fault(s) plays an important role in gear dynamic simulations. Common approaches to evaluating the gear TVMS with spall assume a specific geometry (rectangular, round, elliptical, V-shape etc.) to approximate the features of the spall. The accuracy of geometry-based methods on modeling gear to...
Article
Full-text available
Vibration signal analysis is an important means for bearing fault detection/diagnosis and bearings often operate under time-varying rotational speed conditions. This data article contains vibration datasets collected from bearings with different health conditions under different time-varying speed conditions. The health conditions of the bearing in...
Article
Dynamical modeling of a gear system with faults has been an important research topic for understanding fault features and their associated fault vibration mechanisms. Due to the complicated structures and intricate interactions between the components of the gear system, the fault vibration features and corresponding vibration mechanisms due to toot...
Article
Bearings often operate under time-varying rotational speed conditions. Processing the signal in the time-frequency domain and extracting the Instantaneous Fault Characteristic Frequency (IFCF) and the Instantaneous Shaft Rotational Frequency (ISRF) are important approaches for bearing fault diagnosis under time-varying speed conditions without sign...
Conference Paper
Full-text available
The kurtogram is a spectral analysis tool used to detect non-stationarities in a signal. It can be effectively used to determine the optimal filter for bearing fault feature extraction from a blurred vibration signal, since the transients of the bearing fault-induced signal can be regarded as non-stationary. However, the effectiveness of the kurtog...
Conference Paper
Recent developments in imaging systems have seen the implementation of a radar matched-filtering approach. The goal of the imaging system is to obtain information about an unknown object embedded in the system, by controlling the parameters of the input and measuring the response to the known input. The main merit of using matched filtering in imag...
Conference Paper
Full-text available
Much research has been carried out to investigate the dynamical response of a gear system because of its importance on vibration feature analysis. It is well known that the gearbox casing is one of the most important components of the gear system and plays an important role in signal propagation. However, its effects have widely been neglected with...
Conference Paper
The discrete Fourier transform in Cartesian coordinates has proven to be invaluable in many disciplines. However, in application such as photoacoustics and tomography, a discrete 2D-Fourier transform in polar coordinates is needed. In this paper, a discrete 2D-Fourier transform in polar coordinates is presented. It is shown that numerical implement...
Article
Full-text available
Background: A transfemoral amputee's functional level can be classified from K-level 0 (lowest) to K-level 4 (highest). Knowledge of the biomechanical differences between K3 and K4 transfemoral amputation could help inform clinical professionals and researchers in amputee care and gait assessment. Objectives: Explore gait differences between K3-...
Poster
Full-text available
Aggressive activities can be monitored using wearable devices such as smartwatches. This research compared unilateral and bilateral smartwatches for aggressive movement classification. Results indicate that using one smartwatch on the non-dominant wrist is sufficient to effectively distinguish between aggressive movements and non-aggressive movemen...
Article
Full-text available
Walking on various surfaces encountered in everyday life requires lower limb prosthesis users to continually adapt their movement patterns. Elevated vacuum suspension systems could improve transtibial amputee gait on non-level surfaces; however, research is lacking to guide clinical practice. Twelve transtibial amputees were fitted with the Össur s...
Data
Appendix A (six degree of freedom 57 marker set). (DOCX)
Article
Full-text available
Many important physical phenomena are described by wave or diffusion-wave type equations. Recent work has shown that a transform domain signal description from linear system theory can give meaningful insight to multi-dimensional wave fields. In N. Baddour [AIP Adv. 1, 022120 (2011)], certain results were derived that are mathematically useful for...
Article
Under normal operating conditions, bearings often run under time-varying rotational speed conditions. Under such circumstances, the bearing vibrational signal is non-stationary, which renders ineffective the techniques used for bearing fault diagnosis under constant running conditions. One of the conventional methods of bearing fault diagnosis unde...
Article
Full-text available
Purpose: Describe and quantify how people with transfemoral amputations (TFA) maintain stable gait over a variety of surfaces; including, downhill and uphill, top and bottom-cross-slopes, medial-lateral translations, rolling hills and simulated rocky surfaces. Methods: Ten TFA and ten matched people without amputations (NA) walked in a virtual envi...
Conference Paper
Full-text available
Background: Emerging microprocessor-controlled knee-ankle-foot orthoses (M-SCKAFOs) use multiple sensor systems to guide knee control during gait, and can provide enhanced functions across daily walking activities. M-SCKAFO systems could use machine learning based gait phase detection and/or rule-based gait phase detection for natural walking. Most...
Conference Paper
Full-text available
In recent years, a study has shown that 20% of all powered wheelchair related accidents are caused by distracted driving. These accidents include bumping into objects and/or people that can injure a person, damage the wheelchair, or tip and fall. In many social situations, people who use a powered wheelchair must divide their attention between navi...
Conference Paper
Full-text available
Background Aggressive behaviour can occur in clinical and elderly care settings with people suffering from dementia, mental disorders, or other conditions that affect memory. Since identifying the nature of the event can be difficult with people having memory and communication issues, other methods to identify and record aggressive behaviour would...
Conference Paper
Full-text available
Bearing fault diagnosis under constant operational condition has been widely investigated. Monitoring the bearing vibration signal in the frequency domain is an effective approach to diagnose a bearing fault since each fault type has a specific Fault Characteristic Frequency (FCF). However, in real applications, bearings are often running under tim...
Conference Paper
Full-text available
Gear condition indicators are one of the most important gear transmission fault detection and diagnosis techniques. Various kinds of condition indicators for different kinds of gear fault types (e.g. tooth crack, wear, eccentricity, etc.) have been proposed in the past several decades. However, their relative effectiveness, especially in light of s...
Article
Full-text available
The failure analysis and life prediction of atmospheric plasma-sprayed thermal barrier coatings (APS-TBCs) were carried out for a thermal cyclic process. A residual stress model for the top coat of APS-TBC was proposed and then applied to life prediction. This residual stress model shows an inversion characteristic versus thickness of thermally gro...
Thesis
Full-text available
This thesis presents the design and evaluation of an infant CPR training manikin with a hysteretic thoracic response and real-time feedback mechanism. The work is divided into three parts. First, the absence of thoracic force-displacement curves for infants is an important issue for the design of CPR training manikins. For this reason, a Matlab pr...