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PubMed2005

Using biometrics for participant identification in a research study: a case report.

This paper illustrates the use of biometrics through the application of an iris-based biometrics system for identifying twins and their parents in a longitudinal research study. It explores the use of biometrics (science of measuring physical or anatomical characteristics of individuals) as a technology for correct identification of individuals during longitudinal studies to help ensure data fidelity. Examples of these circumstances include longitudinal epidemiological and genetic studies, clinical trials, and multicenter collaborative studies where accurate identification of subjects over time can be difficult when the subject may be young or an unreliable source of identification information. The use of technology can automate the process of subject identification thereby reducing the need to depend on subject recall during repeated visits thus helping to ensure data quality. This case report provides insights that may serve as useful hints for those responsible for planning system implementation that involves participants' authentication that would require a more secure form of identification.

Adult↗
PubMed2006

Latent curve analyses of longitudinal twin data using a mixed-effects biometric approach.

In a recent article McArdle and Prescott (2005) showed how simultaneous estimation of the biometric parameters can be easily programmed using current mixed-effects modeling programs (e.g., SAS PROC MIXED). This article extends these concepts to deal with mixed-effect modeling of longitudinal twin data. The biometric basis of a polynomial growth curve model was used by Vandenberg and Falkner (1965) and this general class of longitudinal models was represented in structural equation form as a latent curve model by McArdle (1986). The new mixed-effects modeling approach presented here makes it easy to analyze longitudinal growth-decline models with biometric components based on standard maximum likelihood estimation and standard indices of goodness-of-fit (i.e., chi(2), df, epsilon(a)). The validity of this approach is first checked by the creation of simulated longitudinal twin data followed by numerical analysis using different computer programs (i.e., Mplus, Mx, MIXED, NLMIXED). The practical utility of this approach is examined through the application of these techniques to real longitudinal data from the Swedish Adoption/Twin Study of Aging (Pedersen et al., 2002). This approach generally allows researchers to explore the genetic and nongenetic basis of the latent status and latent changes in longitudinal scores in the absence of measurement error. These results show the mixed-effects approach easily accounts for complex patterns of incomplete longitudinal or twin pair data. The results also show this approach easily allows a variety of complex latent basis curves, such as the use of age-at-testing instead of wave-of-testing. Natural extensions of this mixed-effects longitudinal approach include more intensive studies of the available data, the analysis of categorical longitudinal data, and mixtures of latent growth-survival/frailty models.

Biometry↗
PubMed2002

Prenatal prediction of pulmonary hypoplasia: clinical, biometric, and Doppler velocity correlates.

OBJECTIVES: To determine the value of pulmonary artery Doppler velocimetry relative to fetal biometric indices and clinical correlates in the prenatal prediction of lethal lung hypoplasia (LH) in prolonged (>1 week) oligohydramnios. METHODS: Forty-two singleton pregnancies with oligohydramnios associated with premature rupture of membranes ([PROM]; n = 31) or bilateral renal pathology (n = 11) were examined using color-coded Doppler ultrasound in a cross-sectional study design. Mean gestational age was 28.0 +/- 4.3 weeks (range: 20-36 weeks). Thoracic, cardiac, and abdominal circumference and the largest vertical amniotic fluid pocket were measured. Pulsed Doppler measurements of the arterial pulmonary branches were made at the level of the cardiac 4-chamber view. Diagnosis of LH was based on clinical, radiologic, and pathologic criteria. Clinicians were blinded to the prenatal measurements. RESULTS: The prevalence of lethal LH was 43%. In the PROM subset, combination of onset of PROM at or =8 weeks, and degree of oligohydramnios at < or =1 cm presented the highest clinical prediction rate for lethal LH. For both the total group and the PROM subset, the highest prediction rate for lethal LH was presented by thoracic circumference/abdominal circumference ratio, peak systolic velocity in the proximal branch, and time-averaged and end-diastolic velocity in the middle branch of the pulmonary artery. In the PROM subset, the combination of all 3 clinical, biometric, and Doppler parameters revealed the most favorable combination to predict lethal LH (positive predictive value: 100%; accuracy: 93%; and sensitivity: 71%). CONCLUSION: Doppler velocimetry may detect changes in pulmonary artery waveforms in the presence of LH but fails to be the ultimate test for the prenatal prediction of lethal LH. The best prediction can be achieved by combining clinical, biometric, and Doppler parameters.

Adult↗
PubMed1984

Privacy Act of 1974; altered system of records--PHS. Notification of altered system of records: 09-30-0036, "Alcohol, Drug Abuse, and Mental Health Epidemiologic and Biometric Research Data, HHS/ADAMHA/OA".

In accordance with the requirements of the Privacy Act, the Public Health Service (OHS) is publishing a notice of proposal to alter the system of records in the Alcohol, Drug Abuse, and Mental Health Administration (ADAMHA), National Institute of Mental Health (NIMH), entitled, "Mental Health Epidemiologic and Biometric Research Data, HHS/ADAMHA/NIMH," to create an umbrella system of records to include epidemiologic and biometric research data in the areas of alcohol and drug abuse in addition to data already collected and maintained for mental health research. The system is to be retitled, "Alcohol, Drug Abuse, and Mental Health Epidemiologic and Biometric Research Data, HHS/ADAMHA/OA." PHS invites interested persons to submit comments on the proposed alteration on or before November 23, 1984.

Civil Rights↗
PubMed2003

Morphological and biometric revision of the cleithra, opercular and pharyngeal bones of Iberian teleosts belonging to the genus Barbus (Pisces, Cyprinidae).

Species of the genus Barbus present in the Iberian Peninsula are an interesting study group, due to its diversity and complex taxonomic position. In this work, 299 specimens of eight species were studied. All of them are endemic to the Iberian Peninsula, except for Barbus meridionalis. Cleithra, opercular and pharyngeal bones were extracted from each specimen. These bones were morphologically compared and measured, obtaining biometric indices. From these indices, the biometric differences of each bone were analysed with a principal component analysis. Later, a principal component analysis and a discriminant analysis were performed considering the three bones together. The morphological differences and similarities are congruous with the biometric results. In addition, this osteological comparison partially agrees with the present taxonomic position of these species, being a contribution to the systematics and phylogeny of genus.

Animals↗
PubMed2006

Biometric identification using 3D face scans.

Biometrics is an emerging area of bioengineering that pursues the characterization of a person by means of something that the person is or produces. Face recognition is a particularly attractive biometric challenge. Most of the face recognition research performed in the past used 2D intensity images. However, algorithms based on 2D images are not robust to changes of illumination in the environment or orientation of the subject. The ability to acquire 3D scans of human faces removes those ambiguities, since they capture the exact geometry of the subject, invariant to illumination and orientation changes. Unencumbered by those limitations, research in 3D face recognition is now beginning to address a different source of error in biometric recognition: facial geometry deformation caused by facial expressions, which can make 3D algorithms which treat 3D faces as rigid surfaces fail. In this paper, a 3D face recognition framework is proposed to tackle this problem. The framework is composed of three subsystems: expression recognition system, expressional face recognition system and neutral face recognition system. In particular, a system for the recognition of faces with one type of expression (smile) and neutral faces was implemented and tested on a database of 30 subjects. The results proved the feasibility of this framework.

Algorithms↗
PubMed1990

[Biometric parameters of the uterus, ovaries and levels of 17 beta-estradiol (E2) after delivery in sheep].

Biometric changes of uterus, ovaries, follicles and 17 beta-oestradiol (E2) concentrations were investigated in 15 lambing ewes of the Slovak Merino breed in the puerperal period. The sex organs were excised immediately after bleeding from ewes slaughtered on days 1, 7, 17, 25 and 34 post partum (p. p.). Biometric parameters of the body and horns of uterus were measured by a calliper. The ovaries were weighed on an analytical balance, their length, width and height were measured at the same time. The size and number of follicles were determined on the ovary surface. The blood for E2 detection was collected from vena jugularis three and one day before delivery (days -1, -3). Blood samples were also collected after delivery on days 1, 7, 17, 25 and 34. E2 concentrations in the blood serum of ewes were determined by RIA-test-ESTRA kits, designed in one institute at Kosice. The highest weight of uterus body in the test ewes was recorded on day 1 p. p. In the following days the weight of uterus body had a decreasing trend. There were significant differences in the weight of uterus body from day 17 to day 34 p. p., in comparison with the first day after lambing (P less than 0.01). A significant decrease in the length of uterus body was observed from day 17 to day 34 of observation (P less than 0.01; P less than 0.001). An increase in the length of a nongravid horn, observed on day 7 p. p., was followed by a gradual decrease until day 34, similarly like in its weight. No statistically significant differences were found out in the ovary length, width and height. Neither were any greater changes recorded in the weight of ovaries from day 1 to day 34 after delivery. The highest number of small structures (28) observed on day 7 p. p. in the ipsilateral ovary was decreasing in the course of puerperium and the number of follicles larger than 2, 4 and 5 mm was increasing. The highest concentrations of E2 were not recorded on day -1 before delivery. The significantly lowest concentrations of E2 were recorded on day 25 p. p. The above-mentioned results are preliminary and they enlarge the knowledge of biometric parameters of uterus, ovaries, follicles and E2 concentrations after delivery in ewes.

Animals↗
PubMed1977

[Biometric modification of the eyeball in chorioretinal surgery by Lincoff's indentation method].

Biometric modifications were observed on eyeballs operated upon using the indentation method of Lincoff. The biometric modification of the anteroposterieur axis of the eye was studied by an opticoechographic method. 30 eyeballs with retinal detachment were operated upon using the Lincoff method with silastic implants. The length of the eyeball is not modified. But the analysis of the results indicates a significant reduction of the depth of the anterior chamber. This is entirely neutralized by a slight augmentation of the axial length of the vitreous body. The orientation of the implant has an influence on the biometric data. If it is a radial one, the anteriorposterior axis is lengthened; when it is parallel to the limbus, there a shortening with a reduction in the depth of the anterior chamber.

Anterior Chamber↗
PubMed1997

Fetal biometric ratios by transvaginal sonography as a marker for aneuploidies in early pregnancy.

The aim of this study was to obtain by transvaginal sonography in early pregnancy normal biometric charts of some fetal ratios and to evaluate the utility of these ultrasonographic indices as biometric markers for the identification of fetal chromosome abnormalities. The study population included 1054 normal euploid fetuses and 30 fetuses with an abnormal karyotype. We obtained six standard ultrasound measurements by transvaginal sonography at 11-16 weeks' gestation before genetic amniocentesis in patients at risk for genetic disorders. Seven biometric ratios (biparietal diameter/femur length, biparietal diameter/humerus length, head circumference/abdominal circumference, abdominal circumference/femur length, abdominal circumference/humerus length, femur length/foot length, and humerus length/foot length) were calculated and reference curves were plotted. The ratios from aneuploid fetuses showed no differences from reference ranges. Only in trisomy 13 fetuses were abnormal values of head circumference/abdominal circumference, biparietal diameter/humerus length, and biparietal diameter/femur length ratios detected, probably due to the high incidence of microcephaly and central nervous system malformations in these fetuses. The normal values of sonographic ratios obtained by transvaginal sonography in the first and early second trimester of pregnancy cannot generally be considered a useful tool for the detection of chromosomal abnormalities. Only ratios involving cephalic measurements can be used in early pregnancy as screening markers in the detection of trisomy 13 fetuses.

Aneuploidy↗
PubMed1997

Biometric study of acute primary angle-closure glaucoma.

We investigated the biometric characteristics of acute primary angle-closure glaucoma (PACG) patients and sought guidelines to predict subjects at high risk of acute attack. We enrolled 80 patients who suffered acute attack of angle-closure glaucoma and 60 nonglaucoma subjects. The biometric data, measured with A scan ultrasonography, and the outcomes after various treatments were analyzed. Six patients were excluded because they were lost to follow-up. In the acute PACG patients, the axial length (mean +/- standard deviation) was 22.25 +/- 0.77 mm, the anterior chamber depth (corneal thickness included) was 2.28 +/- 0.23 mm, and the lens thickness was 4.94 +/- 0.28 mm. In the nonglaucoma subjects, the axial length was 23.26 +/- 0.76 mm, the anterior chamber depth (corneal thickness included) was 3.11 +/- 0.25 mm, and the lens thickness was 4.48 +/- 0.30 mm. An anterior chamber depth of less than 2.70 mm was the most sensitive (94%) and specific (94%) parameter to differentiate acute PACG patients from nonglaucoma subjects. The intraocular pressure was controlled within the satisfactory range in 58 patients by laser iridectomy, with or without antiglaucoma medication. Eight patients needed additional gonioplasty and eight required filtering surgery to control the intraocular pressure. Our findings provide useful information about the biometric data of eyes of patients with acute angle-closure glaucoma and offer a useful guide to predict those patients at high risk of acute attack.

Acute Disease↗
PubMed1996

Biometrical characteristics and physiological responses to a local cold exposure of the extremities.

The aim of this study was firstly to describe the physiological responses observed in 19 subjects during immersion of the arm up to the elbow in water at 5 degrees C (5 min) followed by a 10-min recovery and secondly, to correlate the observed physiological responses with biometrical characteristics of the subjects (maximal oxygen uptake, VO2max, percentage fat content of whole body, BF, and arm, forearm and hand skinfold thickness). The results showed that the time courses of changes in forearm and hand skin temperature were different compared to those of finger skin temperatures both during local cooling and during rewarming (P < 0.05). Cardiovascular responses (heart rate, systolic and diastolic blood pressures) and finger skin temperatures were not related to the biometrical characteristics of the subjects. However, at the end of the immersion, decreased hand skin temperature was correlated to VO2max (r = 0.45, P < or = 0.05) whereas decreased forearm skin temperature was correlated both to VO2max (r = 0.44, P < or = 0.05) and to skinfold thickness (r = -0.44, P < or = 0.05) but not to BF. During the beginning of the recovery period only, outside, inside forearm and hand skin temperatures were related to VO2max (r = 0.54, P < or = 0.05; r = 0.66, P < or = 0.01 and r = 0.45, P < or = 0.05, respectively) and all the skinfold thicknesses (r = -0.47 to -0.71, P < or = 0.05). It was concluded that the local skin temperature profiles differed according to the upper limb segment both during cooling and during early rewarming. Moreover, VO2max and upper limb skinfold thickness but not BF did influence the forearm and hand skin temperature changes during cooling and early rewarming but not the finger skin temperature changes and cardiovascular responses.

Adult↗
PubMed1991

Genetic basis for remating in Drosophila melanogaster. V. Biometrical and planned comparisons analyses.

Drosophila melanogaster lines previously selected for fast and slow return of female receptivity were crossed to produce 16 lines (2 parental, 2 F1, 4 F2, and 8 backcross lines). Several genetic hypotheses could be tested both through particular planned comparisons among these 16 crosses and with a biometrical analysis. Both analyses identified the difference between the fast and the slow remating speed in these lines as having an autosomal basis. This is in agreement with observations from previous chromosome-substitution analyses. However, the planned comparisons yielded no significant deviations from expectations based on no dominance, no X-chromosomal factors, and no permanent cytoplasmic factors, whereas the biometrical analysis yields the best fit when some of these factors are included.

Animals↗
PubMed1992

A biometrical genetic approach to chromosome analysis in Drosophila: detection of epistatic interactions in geotaxis.

Chromosome analysis has been widely used as a first step in elucidating the genetic architecture of several behaviors of Drosophila melanogaster. These chromosome studies have generally used incomplete designs or fairly simple statistical analyses. Here I reanalyze two data sets on geotaxis from Pyle (1978) and Ksander (1966) using a biometrical genetic design. Results from the biometrical genetic reanalysis suggest that individual differences in geotaxis might be due to genes on all three major chromosomes which show extensive epistatic interactions.

Animals↗
PubMed2005

[Lateral approach to blockade of the sciatic nerve. Biometric data using magnetic resonance imaging].

In the present study we examined 41 volunteers using magnetic resonance imaging to obtain biometric data of the thigh used for a planned blockade of the sciatic nerve via the lateral approach. At a needle entry point 12 cm proximal to the gap of the knee joint at the posterior border of the M. vastus lateralis, the sciatic nerve lies on average at a depth of 5.2 cm (39% of the femoral diameter at this site) with an angle of 10.9 degrees to the horizontal in a dorsal direction. Here the popliteal artery lies on average at a depth of 6.4 cm (48% of the femoral diameter) with an angle of 4.7 degrees to the horizontal in a ventral direction. At the marked point in the middle between the gap of the knee joint and the trochanter major at the posterior border of the M. vastus lateralis, the sciatic nerve is at an average depth of 6.2 cm (40% of the femoral diameter at this site) with an angle of 8.2 degrees in a dorsal direction. At a marked point 5 cm distal of the trochanter major at the posterior border of the M. vastus lateralis, the sciatic nerve is at a depth of 9.1 cm at a dorsal angle of 15.5 degrees (49% of the femoral diameter). The lateral blockade of the sciatic nerve at different sites of the thigh is a technique which is easy to plan with the presented biometric data. The popliteal artery could be reached only at the distal puncture point using a deep puncture and an angle in the ventral direction.

Adult↗
PubMed2006

[Accommodation ability under the aspect of refractive, demographic, and biometric parameters].

PURPOSE: The aim of this study was to evaluate the accommodation ability in healthy phakic eyes in relation to refraction and biometric parameters in order to get comparable results for patients with the accommodative 1 CU posterior chamber lens. METHODS: The study included 120 normal eyes of 120 patients (77 males, 43 females, mean age: 40+/-18, range: 11-70 years). The inclusion criteria were spherical equivalent for distance refraction <2 D, astigmatism <1.5 D, and a best-corrected visual acuity > or =0.8. Exclusion criteria were diabetes, glaucoma, cataract, traumas, or previous surgery. Subjects were divided into six age groups at increments of 10 years. Each group consisted of 20 subjects. Measurements included subjective and objective refraction (D), the accommodation ability (D) assessed with an accommodometer, and biometric parameters using the IOLMaster. In addition, the relation of anterior chamber depth and length of the eye was calculated for analyzing the relationship of anterior eye segment and accommodation. RESULTS: The spherical equivalent for distance refraction was 0.04+/-0.6 D with a range of -1.5 to 2.0 D. There was no sex-related significant difference of accommodation range. The accommodation range (D) decreased significantly with increasing age (p<0.0001, r=-0.895). The highest decrease could be found between the ages of 30 and 50 years. In subsequent years, the decline in accommodation ability was comparatively less. In association with the anterior chamber depth and the relation of anterior chamber depth and length of the eye, the accommodation ability fell with increasing age (p<0.001). The length of the eye did not correlate with the accommodation ability (p=0.8). CONCLUSION: There is a strong relationship between accommodation ability and age. Accommodation ability decreases strongly from the 3rd to the 5th decade; after that the loss of accommodation ability is relatively lower. The increase in lens thickness during the life span can implicate a correlation between the change of anterior chamber depth in relation to the length of the eye and a decrease of accommodation ability. Our results confirm Duane's hypothesis of accommodation and age.

Accommodation, Ocular↗
PubMed2003

Forensic pathological aspects of postmortem imaging of gunshot injury to the head: documentation and biometric data.

To determine the value of imaging procedures such as computer tomography (CT) and magnetic resonance imaging (MRI) of the head in providing additional information of forensic relevance, we examined 17 cadavers of human victims of gunshot wounds to the head. Three of the victims briefly survived the gunshot wound. The weapons involved were all guns with low muzzle energy (<550 J), i.e., handguns and low-velocity rifles. In the majority of cases ( n=15) a penetrating wound to the head was found, only two cases showed the bullet lodged in the brain. In some cases, imaging of the skull and brain was performed prior to autopsy; in others imaging took place after autopsy on the isolated, formalin-fixed brain. The imaging findings were correlated with the criminological data and the results of macroscopic and microscopic examination of the brain. The findings on the bony structures of the head provided imaging criteria for differentiation between entrance and exit of the gunshot wounds, which corresponded to the forensic pathological findings at autopsy. CT scans and MRI of the cerebral parenchyma revealed lanes of opaque bone and missile fragments along the course of the missile, which allowed recognition of the missile track in 3D reconstruction. Biometric reconstruction allowed easy determination of the angle of the missile track in all three planes. Examination of the parenchymal structures and imaging of the isolated, formalin-fixed brain enabled tracking of the missile path directly along the zone of destruction as well as demonstration of secondary changes such as air bubbles along the bullet course, hemorrhage and edema. The significance of a translucent zone surrounding the missile track in several cases remains unclear; it probably represents tissue destruction secondary to temporary cavitation. The imaging procedures described here allowed excellent documentation of in situ conditions, while the storing of data enabled biometric reconstruction for determination of the angle of trajectory, of entrance and exit wounds, and the extent of tissue damage along the missile track and, possibly, in the zone of temporary cavitation.

Adult↗
PubMed2007

Heritability and shared environment estimates for myopia and associated ocular biometric traits: the Genes in Myopia (GEM) family study.

To examine the familial correlations, heritability (h(2)) and common environmental components (c(2)) of myopia and ocular biometric traits (all treated as continuous outcomes) in families collected through the Genes in Myopia (GEM) family study in Australia. A total of 132 pedigrees (723 participants) were recruited for this study. All individuals completed a risk factor questionnaire and underwent a detailed eye examination including spherical equivalent (SphE) and ocular biometric measurements of axial length (AL), anterior chamber depth (ACD) and corneal curvature (CC). Familial correlations were calculated and h(2) and c(2) were estimated using a variance component model that assumes a multivariate t distribution within each pedigree. Two definitions of common environments (c(2)) were considered: nuclear family (current) shared environment (Model 1) and sib-ship (childhood) shared environment (Model 2). Population ascertainment adjustment was performed using the Blue Mountains eye study dataset. The trends observed for familial correlations suggested that SphE is influenced by both environmental and genetic factors whereas AL, ACD and CC are predominantly genetically determined. This was largely confirmed by variance components modelling. Heritability estimates (adjusted for age, sex and years of education) from the best fitting ACE model (Model 2, childhood shared environment) were 0.50 +/- 0.05 for SphE, 0.73 +/- 0.04 for AL, 0.78 +/- 0.04 for ACD and 0.16 +/- 0.06 for CC. Childhood environmental effects were significant with c(2) estimated to be 0.33 +/- 0.04 for SphE, 0.06 +/- 0.03 for AL, 0.22 +/- 0.04 for ACD and 0.10 +/- 0.05 for CC. Age was associated with SphE, total years of education was associated with AL and sex was associated with all traits studied. We used a novel and conservative approach to account for and estimate common environmental effects by specifying either nuclear family or sib-ship environment when estimating heritability estimates and showed that all traits examined (SphE, AL, ACD and CC) are heritable, thus reflecting a genetic component. These traits therefore all represent candidates for quantitative trait linkage analyses.

Adult↗
PubMed1985

The ratio of lens thickness to axial length for biometric standardization in angle-closure glaucoma.

Biometric measurements were made by ultrasonography in 44 left eyes of 44 patients with primary angle-closure glaucoma. We defined the ratio between the lens thickness and the axial length (lens thickness/axial length factor) as a representative and unifying unit for biometric assessment of the eye. This factor defined the relationship between the lens, iris, and cornea and thus the status of the angle. Lens thickness/axial length factor values were found to be age dependent and were greater than normal for most age groups with angle-closure glaucoma. The mean normal value was 1.91 +/- 0.44; the mean values for patients in different age groups with angle-closure glaucoma ranged from 1.87 +/- 0.11 to 2.39 +/- 0.17.

Adolescent↗