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1.
Front Psychol ; 12: 733173, 2021.
Article in English | MEDLINE | ID: mdl-34712180

ABSTRACT

In this paper, we describe the model for faculty diversity developed as part of the Professorial Advancement Initiative (PAI) funded under the NSF AGEP program. The PAI, consisting of 12 of the 14 Big Ten Academic Alliance universities, had the goal of doubling the rate at which the universities hired tenure-track minoritized faculty, defined by National Science Foundation as African Americans, Hispanic/Latinx, Native Americans, and Pacific Islanders. This paper reviews the key programmatic elements of the PAI and discusses lessons learned and the practices developed that helped the Alliance achieve its faculty diversity goal.

2.
Nutr Rev ; 76(9): 708-721, 2018 09 01.
Article in English | MEDLINE | ID: mdl-30010929

ABSTRACT

Folic acid, a B vitamin, is vital for early neurodevelopment and is well known for its protective effect against neural tube defects. Various national health agencies worldwide recommend that women of childbearing age take approximately 0.4 to 1 mg of supplemental folic acid daily to reduce the risk of neural tube defects in offspring. Several countries have tried to promote folic acid intake through mandatory fortification programs to reduce neural tube defects. Supplementation combined with mandatory fortification of foods has led to high levels of folic acid and related metabolites in women of childbearing age. Recent studies have reported that oversupplementation, defined as exceeding either the recommended dietary allowance or the upper limit of the daily reference intake of folic acid, may have negative effects on human health. This review examines whether maternal oversupplementation with folic acid affects the neurodevelopment of offspring. Data from animal studies suggest there are behavioral, morphological, and molecular changes in the brain of offspring. Additional studies are required to determine both the dosage of folic acid and the timing of folic acid intake needed for optimal neurodevelopment in humans.


Subject(s)
Dietary Supplements/adverse effects , Folic Acid/adverse effects , Neurodevelopmental Disorders/chemically induced , Overnutrition/etiology , Pregnancy Complications/etiology , Prenatal Exposure Delayed Effects/chemically induced , Animals , Female , Folic Acid/administration & dosage , Food, Fortified , Humans , Infant, Newborn , Male , Neural Tube Defects/prevention & control , Pregnancy , Recommended Dietary Allowances
3.
Simul Healthc ; 12(6): 356-363, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29210891

ABSTRACT

INTRODUCTION: Although recent literature suggests that students should be trained in the care of persons with disability (PWDs) as a form of cultural sensitivity (CS), healthcare professionals may receive limited experience during their formal training. After pharmacy students in 2 previous years of testing failed to adequately assess and plan for the care of a standardized patient's chief complaint and disability in an Objective Structured Clinical Examination (OSCE), the investigators added debriefing to the OSCE to determine if it would improve student's ability to assess and plan for the care of PWD. METHODS: Two sequentially enrolled second-year pharmacy school student cohorts participated in this study (control n = 90; intervention n = 82). During the OSCE, students interviewed and examined a standardized patient with a simulated physical disability and other chronic disease states. Students were then instructed to develop a care plan considering the patient's disability and other disease states. The intervention cohort received debriefing; the control did not. Students documented the care plan in a subjective, objective, assessment, and plan (SOAP) note. Investigators assessed SOAP note score (general ability of students to write a SOAP note) and CS score (specific ability to care for PWD) to determine the effectiveness of the debriefing. RESULTS: The intervention group showed a significantly higher percent mean CS score than the control group (93.6% ± 19% and 61.1% ± 30.7%, respectively, P < 0.001), translating to a mean of 56.2/60 points earned for the intervention group and 36.7/60 points earned for the control group. Scores ranged from 0 to 60 points for both intervention and control groups. Students in the intervention group had an absolute improvement in pass rates (those students scoring ≥70% on the OSCE) of 59.4% with 92.7% of the students passing in the intervention group versus 33.3% of the students passing in the control group (P < 0.001). The overall SOAP note scores were no different between the 2 cohorts (P = 0.353). CONCLUSIONS: Debriefing added to an OSCE improved students' performance in developing care plans for disabled patients. Ideally, longitudinal studies should be completed to determine if these skills transfer from debriefings to clinical practice. Development of effective training and assessment methods is essential for students to obtain adequate skills and knowledge to care for persons with disabilities.


Subject(s)
Disabled Persons/rehabilitation , Education, Pharmacy/organization & administration , Formative Feedback , Adult , Clinical Competence , Communication , Educational Measurement , Female , Humans , Male , Young Adult
5.
Am J Public Health ; 104(11): 2103-13, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25211758

ABSTRACT

OBJECTIVES: We explored differences in health and education outcomes between children living in social housing and not, and effects of social housing's neighborhood socioeconomic status. METHODS: In this cohort study, we used the population-based repository of administrative data at the Manitoba Centre for Health Policy. We included children aged 0 to 19 years in Winnipeg, Manitoba, in fiscal years 2006-2007 to 2008-2009 (n = 13,238 social housing; n = 174,017 others). We examined 5 outcomes: age-2 complete immunization, a school-readiness measure, adolescent pregnancy (ages 15-19 years), grade-9 completion, and high-school completion. Logistic regression and generalized estimating equation modeling generated rates. We derived neighborhood income quintiles (Q1 lowest, Q5 highest) from average household income census data. RESULTS: Children in social housing fared worse than comparative children within each neighborhood income quintile. When we compared children in social housing by quintile, preschool indicators (immunization and school readiness) were similar, but adolescent outcomes (grade-9 and high-school completion, adolescent pregnancy) were better in Q3 to Q5. CONCLUSIONS: Children in social housing had poorer health and education outcomes than all others, but living in social housing in wealthier areas was associated with better adolescent outcomes.


Subject(s)
Educational Status , Health Status , Public Housing , Residence Characteristics , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Manitoba/epidemiology , Outcome and Process Assessment, Health Care , Public Housing/statistics & numerical data , Residence Characteristics/statistics & numerical data , Socioeconomic Factors , Young Adult
6.
Can J Cardiol ; 29(5): 606-12, 2013 May.
Article in English | MEDLINE | ID: mdl-23395221

ABSTRACT

BACKGROUND: Hypertension is a substantial health concern because it poses significant risks for cardiovascular morbidity and mortality and is highly prevalent in the population. Tracking hypertension is important because it is a risk factor for other conditions, but prevalence estimates might vary depending on the data source used. METHODS: This report describes 3 national population-based data sources for estimating hypertension prevalence in Canada and discusses their strengths and weaknesses to aid in their use for policy and program planning. They are compared based on: sample coverage, case identification, and prevalence estimates. RESULTS: Each source produces a different measure of hypertension prevalence, as follows: (1) diagnosed hypertension from the Canadian Chronic Disease Surveillance System (CCDSS) (2007/2008); (2) self-reported diagnosed hypertension from the Canadian Community Health Survey (CCHS) (2007-2008); and, (3) physically-measured hypertension from the Canadian Health Measures Survey (CHMS) (2007-2009). Crude rates and counts of hypertension prevalence among individuals aged 20 to 79 years of age, excluding pregnant women, are compared, resulting in prevalence ranging from 18.2% in self-report data to 20.3% in diagnosed data. The data sources differ in terms of target population, case identification, and limitations, which affects the estimates. CONCLUSIONS: Each source has unique strengths and is best suited for addressing particular research questions. For example, diagnosed hypertension can be used to determine health care utilization patterns, self-reported to examine health determinants, and measured high blood pressure to improve awareness, treatment, and control. Combined, they can address multiple issues and increase our knowledge of hypertension in Canada.


Subject(s)
Diagnostic Techniques and Procedures , Health Surveys , Hypertension/diagnosis , Adult , Aged , Canada/epidemiology , Female , Humans , Hypertension/epidemiology , Male , Middle Aged , Pregnancy , Prevalence , Public Health Surveillance , Self Report , Young Adult
7.
Am J Pharm Educ ; 75(8): 157, 2011 Oct 10.
Article in English | MEDLINE | ID: mdl-22102747

ABSTRACT

OBJECTIVE: To describe a systematic assessment process that provides continuous improvement in the curriculum, supports faculty development, and enhances student learning outcomes. DESIGN: Teams of faculty members, students, and course instructors conducted course assessments, which consisted of monitoring the delivered instruction for agreement with planned content and course integration within the curriculum, and providing ongoing feedback for improving course content, course management, faculty teaching, and student learning experiences. ASSESSMENT: Areas needing improvement were identified and appropriate changes were made. Improvements were achieved in course policy standardization, course integration within the curriculum, faculty teaching behaviors, and student experiences. CONCLUSION: The curriculum assessment plan provides a structured method of monitoring and delivering continuous quality improvement.


Subject(s)
Curriculum/standards , Education, Pharmacy/standards , Educational Measurement/standards , Models, Educational , Quality Improvement/standards , Curriculum/trends , Education, Pharmacy/trends , Humans , Quality Improvement/trends , Students, Pharmacy
8.
IEEE Trans Image Process ; 20(11): 3063-72, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22010123

ABSTRACT

Two-band analysis-synthesis filters or wavelet filters are used pervasively for compressing natural images. Both FIR and IIR filters have been studied in this context, the former being the most popular. In this paper, we examine the compression performance of these two-band filters in a dyadic wavelet decomposition and attempt to isolate features that contribute most directly to the performance gain. Then, employing the general exact reconstruction condition, hybrid FIR-IIR analysis-synthesis filters are designed to maximize compression performance for natural images. Experimental results are presented that compare performance with the popular biorthogonal filters in terms of peak SNR, subjective quality, and computational complexity.

9.
IEEE Trans Image Process ; 19(11): 3064-71, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20529744

ABSTRACT

In this correspondence, a new two-channel overlapped block transform is introduced by prefiltering the Haar transform. The prefiltering employs plane rotations with one single rotation angle to achieve high computational efficiency. The resulting transform is equivalent to a periodically time-varying (PTV) filter bank. The proposed transform or PTV filter bank has several advantages for image coding. First, symmetric extension is very easily performed at the boundaries in spite of the fact that the filters are asymmetric. Second, arithmetic complexity can be reduced to simple shifts and adds. Finally, the performance for image compression is shown to be high, both in terms of visual quality and PSNR. As a result, the proposed transform is a competitive alternative to the 5/3 and the 9/7 filters, which are currently popular for subband/wavelet image coders.

10.
IEEE Trans Image Process ; 18(8): 1717-23, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19423446

ABSTRACT

Subband decompositions for image coding have been explored extensively over the last few decades. The condensed wavelet packet (CWP) transform is one such decomposition that was recently shown to have coding performance advantages over conventional decompositions. A special feature of the CWP is that its design and implementation are performed in the cyclic frequency domain. While performance gains have been reported, efficient implementations of the CWP (or more generally, efficient implementations of cyclic filter banks) have not yet been fully explored. In this paper, we present efficient block-based implementations of cyclic filter banks along with an analysis of the arithmetic complexity. Block-based cyclic filter bank implementations of the CWP coder are compared with conventional subband/wavelet image coders whose filter banks are implemented in the time domain. It is shown that block-based cyclic filter bank implementations can result in CWP coding systems that outperform the popular image coding systems both in terms of arithmetic complexity and coding performance.

11.
IEEE Trans Med Imaging ; 27(3): 370-7, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18334432

ABSTRACT

A new technique is presented for interpolating between grey-scale images in a medical data set. Registration between neighboring slices is achieved with a modified control grid interpolation algorithm that selectively accepts displacement field updates in a manner optimized for performance. A cubic interpolator is then applied to pixel intensities correlated by the displacement fields. Special considerations are made for efficiency, interpolation quality, and compression in the implementation of the algorithm. Experimental results show that the new method achieves good quality, while offering dramatic improvement in efficiency relative to the best competing method.


Subject(s)
Algorithms , Artificial Intelligence , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Pattern Recognition, Automated/methods , Subtraction Technique , Image Enhancement/methods , Reproducibility of Results , Sensitivity and Specificity
12.
IEEE Trans Image Process ; 17(2): 177-89, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18270110

ABSTRACT

In subband/wavelet image coding, size-limited subband decompositions are ordinarily used to avoid increasing the number of samples that need to be coded. To reduce coding distortions that can occur at the borders, the symmetric extension filter bank is typically employed. This paper introduces some new perspectives and improvements to that decomposition. The symmetric extension filter bank is couched in the cyclic frequency domain, providing a framework that accommodates FIR and IIR filters in a natural way, all with perfect reconstruction. IIR filters with both rational and irrational transfer functions can be implemented and, in the context of symmetric extension, can accommodate IIRs that effectively have perfect stopband suppression. Enhancements to the filter bank at a tree-structured system level are also presented and include the application of spectral reversal correction and a transition band normalization approach to designing the constituent filters of the symmetric extension wavelet packet transform.


Subject(s)
Algorithms , Computer Graphics , Data Compression/methods , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Signal Processing, Computer-Assisted , Numerical Analysis, Computer-Assisted , Reproducibility of Results , Sensitivity and Specificity
13.
J Affect Disord ; 104(1-3): 37-44, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17367867

ABSTRACT

BACKGROUND: Depressed patients show mood-congruent errors in the identification of emotion in facial expressions. Errors consist of impaired performance (recognition errors) and negative bias (seeing faces as sadder than they are). This abnormal processing may both reflect and contribute to the negative affective state. In this study, we administered an emotional recognition in facial expression task to women with premenstrual dysphoric disorder (PMDD) to determine whether processing errors similar to those in depression were present and whether they were confined to the luteal phase (i.e., state dependent). METHODS: The Facial Discrimination Task (FDT) was administered in the follicular and luteal phases to women with PMDD (n=28) and asymptomatic controls (n=27). RESULTS: ANOVA with repeated measures identified significantly increased negative judgments (both performance errors and bias) in women with PMDD during the luteal phase (more neutral to sad misjudgments and higher negative bias index) as well as impaired "specificity" of judgments [an inability to discriminate neutral from emotional stimuli] (diagnosis by phase interactions, p<0.05), findings similar to those observed in depression. No menstrual cycle effects were seen in controls, and no differences between patients and controls were seen on a control task (age assessment of pictured subjects). LIMITATIONS: The levels of significance obtained were modest and would not withstand correction for multiple comparisons. CONCLUSION: Women with PMDD display a luteal phase-dependent impairment (negative bias) in the processing of non-verbal affective information. This negative bias may contribute to the generation of negative mood states during the luteal phase and could suggest the presence of dysfunction in those brain regions whose coordinated activity mediates the recognition of emotion in facial expression.


Subject(s)
Affect , Discrimination, Psychological , Facial Expression , Judgment , Menstrual Cycle/physiology , Premenstrual Syndrome/psychology , Adult , Depression/diagnosis , Depression/epidemiology , Depression/psychology , Diagnostic and Statistical Manual of Mental Disorders , Female , Follicular Phase/physiology , Humans , Luteal Phase/physiology , Premenstrual Syndrome/diagnosis , Premenstrual Syndrome/epidemiology , Psychological Tests , Recognition, Psychology
14.
BJOG ; 112(8): 1016-21, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16045511

ABSTRACT

OBJECTIVES: To obtain fetal heart rate, detailed fetal electrocardiography (fECG) signals and uterine contractions during labour using a single device. DESIGN: Prospective observational study. SETTING: Delivery suite at a tertiary referral hospital, London, UK. POPULATION: Fifteen patients at median gestation of 39 weeks (range 24-41) were recruited at median cervical dilatation of 4.0 cm (range 0-10) of whom 8/15 (53%) had intact amniotic membranes. METHODS: Using 12 abdominally sited electrodes, we recorded the composite abdominal signal in pregnancies intrapartum. The recorded data were analysed off-line using a blind signal separation technique. MAIN OUTCOME MEASURES: Success of signal separation and fECG time intervals. RESULTS: Successful fECG signal acquisition was achieved in 12/15 (80%) patients and an averaged fECG waveform acquired. In these patients, P and QRS waves were seen in all cases, and T waves in 11/12 (92%). True beat-to-beat heart rate (HR) was displayed and measures of its variability obtained. The mother's ECG and uterine electrical activity, shown to match tocographically recorded uterine contractions, were also separated and displayed. Failure to acquire fECG in three cases was attributed to excessive abdominal muscular activity and electrical interference. CONCLUSIONS: This study demonstrates a non-invasive technique that displays detailed intrapartum fECG waveforms, HR variability, maternal ECG and uterine contractions simultaneously, all in a single device and which avoids the potential risks of invasive monitoring with a fetal scalp electrode.


Subject(s)
Cardiotocography/methods , Electrocardiography/methods , Heart Rate, Fetal/physiology , Uterine Contraction/physiology , Cardiotocography/instrumentation , Electrocardiography/instrumentation , Electrodes , Feasibility Studies , Female , Humans , Infant, Newborn , Male , Pregnancy , Pregnancy Outcome , Prospective Studies
15.
J Cardiovasc Magn Reson ; 7(2): 425-32, 2005.
Article in English | MEDLINE | ID: mdl-15881525

ABSTRACT

The accurate representation of two-dimensional images in three dimensions has become important for many medical imaging applications and for cardiac magnetic resonance imaging (MRI) in particular. Reconstruction methods applied after data acquisition can produce three-dimensional information from two-dimensional data and make applications such as surgical planning more effective. Current reconstruction techniques usually demand contrast agents, and can suffer due to poor segmentation and sampling constraints that cause surface irregularities and distort dimensions. The novel technique presented here for anatomical modeling uses adaptive control grid interpolation (ACGI) to approximate data not captured by scanning, and a progressive shape-element segmentation technique to complete reconstruction. Quantitative validations conducted on models of pediatric cardiac malformations have confirmed the theoretical advantages of this technique, and that higher quality is achieved than with competing methods based on geometric parameters. Vascular diameters from reconstructions showed errors of less than 1% for a known geometry as compared to over 9% for competing methods. Qualitatively, models produced with the new methodology displayed substantial improvement over alternatives. Approximately 50 rare cardiac structures, including surgically altered Fontan and atypical aortic anatomies, have been reconstructed. All data used to create these reconstructions were acquired using standard pulse sequences and without contrast agents. Benefits of the new technique are particularly evident when complex vascular configurations complicate reconstruction. The proposed methodology enables a powerful tool allowing physicians to analyze and manipulate highly accurate and clearly presented vascular structures in an interactive medium.


Subject(s)
Heart Defects, Congenital/pathology , Image Enhancement/methods , Magnetic Resonance Imaging/methods , Child , Fontan Procedure , Heart Defects, Congenital/surgery , Humans , Reproducibility of Results
16.
Arch Gen Psychiatry ; 62(2): 154-62, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15699292

ABSTRACT

CONTEXT: Alternative and over-the-counter medicines have become increasingly popular choices for many patients who prefer not to take traditional antidepressants. The adrenal androgen and neurosteroid dehydroepiandrosterone (DHEA) is available as over-the-counter hormonal therapy and previously has been reported to have antidepressant-like effects. OBJECTIVE: To evaluate the efficacy of DHEA as a monotherapy treatment for midlife-onset depression. DESIGN: A double-blind, randomized, placebo-controlled, crossover treatment study was performed from January 4, 1996, through August 31, 2002. Settings The National Institute of Mental Health Midlife Outpatient Clinic in the National Institutes of Health Clinical Center, Bethesda, Md. Patients Men (n = 23) and women (n = 23) aged 45 to 65 years with midlife-onset major or minor depression participated in this study. None of the subjects received concurrent antidepressant medications. Intervention Six weeks of DHEA therapy, 90 mg/d for 3 weeks and 450 mg/d for 3 weeks, and 6 weeks of placebo. MAIN OUTCOME MEASURES: The 17-Item Hamilton Depression Rating Scale and Center for Epidemiologic Studies Depression Scale. Additional measures included the Derogatis Interview for Sexual Functioning. Results were analyzed by means of repeated-measures analysis of variance and post hoc Bonferroni t tests. RESULTS: Six weeks of DHEA administration was associated with a significant improvement in the 17-Item Hamilton Depression Rating Scale and the Center for Epidemiologic Studies Depression Scale ratings compared with both baseline (P<.01) and 6 weeks of placebo treatment (P<.01). A 50% or greater reduction in baseline Hamilton Depression Rating Scale scores was observed in 23 subjects after DHEA and in 13 subjects after placebo treatments. Six weeks of DHEA treatment also was associated with significant improvements in Derogatis Interview for Sexual Functioning scores relative to baseline and placebo conditions. CONCLUSION: We find DHEA to be an effective treatment for midlife-onset major and minor depression.


Subject(s)
Dehydroepiandrosterone/therapeutic use , Depressive Disorder, Major/drug therapy , Depressive Disorder/drug therapy , Aged , Ambulatory Care , Cross-Over Studies , Depressive Disorder/diagnosis , Depressive Disorder/psychology , Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/psychology , Double-Blind Method , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Personality Inventory , Placebos , Psychiatric Status Rating Scales , Severity of Illness Index , Treatment Outcome
17.
IEEE Trans Image Process ; 13(11): 1424-31, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15540452

ABSTRACT

This paper introduces an improved structure for directional filter banks (DFBs) that preserves the visual information in the subband domain. The new structure achieves this outcome while preserving both the efficient polyphase implementation and the exact reconstruction property. The paper outlines a step-by-step framework in which to examine the DFB, and within this framework discusses how, through the insertion of post-sampling matrices, visual distortions can be removed. In addition to the efficient tree structure, attention is given to the form and design of efficient linear phase filters. Most notably, linear phase IIR prototype filters are presented, together with the design details. These filters can enable the DFB to have more than a three-fold improvement in complexity reduction over quadrature mirror filters (QMFs).


Subject(s)
Algorithms , Artificial Intelligence , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Information Storage and Retrieval/methods , Pattern Recognition, Automated/methods , Signal Processing, Computer-Assisted , Computer Graphics , Imaging, Three-Dimensional/methods , Numerical Analysis, Computer-Assisted , Reproducibility of Results , Sensitivity and Specificity , Subtraction Technique
18.
Biol Psychiatry ; 54(7): 757-62, 2003 Oct 01.
Article in English | MEDLINE | ID: mdl-14512217

ABSTRACT

BACKGROUND: Premenstrual syndrome (PMS) involves an aberrant behavioral response to normal hormone secretion. Pathogenetic theories posit abnormal modulation of gamma-aminobutyric acid (GABA) transmission in the brain by neuroactive metabolites of progesterone (neurosteroids). In earlier transcranial magnetic stimulation (TMS) studies of the motor cortex, we showed that inhibition increases in the luteal phase, consistent with neurosteroid action at the GABA(A) receptor. Here, we studied women with PMS to see if their response to endogenous progesterone differed from that of control subjects. METHODS: We studied nine women with PMS and 14 control subjects during the midfollicular and luteal phases with paired TMS. Subthreshold conditioning TMS was followed by test stimulation that produced a motor evoked potential (MEP) in a hand muscle. We gave pairs at each of seven intervals (2-10 msec) and unconditioned stimuli, measuring the amplitude ratio of the average MEP from the pairs at each interval to that from the unconditioned stimuli (ratio < 1 = inhibition). RESULTS: Both groups showed the same follicular phase response to paired TMS. Control subjects showed more inhibition in the luteal phase. Women with PMS showed relative facilitation. CONCLUSIONS: This is the first physiological evidence for an abnormal brain response to progesterone in PMS.


Subject(s)
Evoked Potentials, Motor/physiology , Follicular Phase/physiology , Luteal Phase/physiology , Motor Cortex/physiopathology , Premenstrual Syndrome/physiopathology , Adult , Analysis of Variance , Case-Control Studies , Conditioning, Classical , Diagnostic and Statistical Manual of Mental Disorders , Differential Threshold , Estradiol/analysis , Female , Humans , Progesterone/analysis , Time Factors
19.
BJOG ; 110(7): 668-78, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12842058

ABSTRACT

OBJECTIVES: To document the duration of fetal cardiac time intervals in uncomplicated singleton pregnancies using a novel non-invasive fetal electrocardiography (fECG) system and to demonstrate this technique's ability to acquire recordings in twin and triplet pregnancies. DESIGN: Prospective cross sectional observational study. SETTING: Antenatal wards and clinics, day assessment unit and centre for fetal care at a tertiary referral hospital, London, UK. POPULATION OR SAMPLE: Three hundred and four singleton and multiple pregnancies, 15-41 weeks of gestation. METHODS: Using electrodes sited on the maternal abdomen, a fetal electrocardiography (fECG) system was developed and tested on 304 pregnant women from 15 to 41 weeks of gestation, of whom 241 were uncomplicated singletons, 58 had twin and 5 had triplet pregnancies. The composite abdominal signals were stored on a laptop computer and the fECG derived off-line using a digital signal processing technique. For singletons, linear regression was used to analyse PR, QRS, QT and QTc intervals, and construct time-specific reference ranges. MAIN OUTCOME MEASURE: Duration of fECG time intervals as a function of gestational age. Success of signal separation in singleton, twin and triplet pregnancies. RESULTS: For singletons, a total of 250 recordings was obtained from 241 individuals with a signal separation success rate of 85% (213/250). Success rates were significantly poorer between 27 and 36 weeks of gestation (2 x k chi(2), P < 0.0001), with 84% (31/37) of separation failures occurring during this period. P, Q, R and S waves were seen in all cases where fetal signals were separated and were used to generate fECG time interval reference ranges. In 22% (43/199) of analysed cases, no T waves were identified, 63% (27/43) of whom were < or =24 weeks of gestation. In twins and triplets, separate fetal signals were obtained in 78% (91/116) and 93% (14/15), respectively; P, Q, R and S waves were evident in all averaged fECGs, while T waves were identified in 59% (54/91) and 57% (8/14). CONCLUSIONS: This study provides reference ranges with gestation for fECG intervals derived non-invasively from normal singleton pregnancies and demonstrates the feasibility of obtaining complete fECG recordings non-invasively across a wide gestational range in pregnancies of all pluralities. The fECG time intervals described will enable the identification of pathological fECG recordings from high risk pregnancies where fECG abnormalities are suspected.


Subject(s)
Electrocardiography/methods , Heart Rate, Fetal/physiology , Pregnancy, Multiple/physiology , Cardiotocography , Cross-Sectional Studies , Female , Gestational Age , Humans , Pregnancy , Prospective Studies , Reference Values , Sensitivity and Specificity , Triplets , Twins
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