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BioMed Research International 2015Morphometry is introduced as quantitative approach to seek information concerning variations and changes in the forms of organisms that described the relationship... (Review)
Review
Morphometry is introduced as quantitative approach to seek information concerning variations and changes in the forms of organisms that described the relationship between the human body and disease. Scientists of all civilization, who existed until today, examined the human body using anthropometric methods. For these reasons, anthropometric data are used in many contexts to screen for or monitor disease. Anthropometry, a branch of morphometry, is the study of the size and shape of the components of biological forms and their variations in populations. Morphometrics can also be defined as the quantitative analysis of biological forms. The field has developed rapidly over the last two decades to the extent that we now distinguish between traditional morphometrics and the more recent geometric morphometrics. Advances in imaging technology have resulted in the protection of a greater amount of morphological information and have permitted the analysis of this information. The oldest and most commonly used of these methods is radiography. With developments in this area, CT and MRI have also been started to be used in screening of the internal organs. Morphometric measurements that are used in medicine, are widely used in the diagnosis and the follow-up and the treatment of the disease, today. In addition, in cosmetology use of these new measurements is increasing every day.
Topics: Anthropometry; Biometry; Diagnostic Imaging; Humans
PubMed: 26413519
DOI: 10.1155/2015/404261 -
Revista Brasileira de Enfermagem 2019to analyze scientific evidence available in health literature on ethics, standardization and biometric indicators. (Review)
Review
OBJECTIVE
to analyze scientific evidence available in health literature on ethics, standardization and biometric indicators.
METHOD
an integrative review carried out in August 2016, on the databases: National Library of Medicine, Literatura Latino-Americana e do Caribe em Ciências da Saúde (Latin-American and Caribbean Literature on Health Sciences), and on the library Scientific Electronic Library Online. The review included primary articles on: ethics, standardization and biometric indicators, in Portuguese, English, or Spanish; and excluded studies that were not found as full texts, as well as opinions, commentary, reviews, theses, and dissertations. For the evaluation of the articles, it was used evidence levels from one to five.
RESULTS
eight articles were included, with scientific evidence levels 4 and 5: scientific productivism, production evaluation systems, internationalization, impact factor, classification of journals, and adequate and inadequate practices for publication.
CONCLUSION
it was verified the need for publications with higher evidence levels so that Brazilian journals can follow international standards dealing with research ethics.
Topics: Biometric Identification; Biometry; Brazil; Ethics; Humans; Publications; Reference Standards
PubMed: 31644766
DOI: 10.1590/0034-7167-2018-0283 -
Computational Intelligence and... 2018
Topics: Artificial Intelligence; Biometric Identification; Biometry; Electroencephalography; Humans
PubMed: 29977277
DOI: 10.1155/2018/5483921 -
Sensors (Basel, Switzerland) Mar 2022Secure and reliable sensing plays the key role for cognitive tracking i.e., activity identification and cognitive monitoring of every individual. Over the last years...
Secure and reliable sensing plays the key role for cognitive tracking i.e., activity identification and cognitive monitoring of every individual. Over the last years there has been an increasing interest from both academia and industry in cognitive authentication also known as biometric recognition. These are an effect of individuals' biological and physiological traits. Among various traditional biometric and physiological features, we include cognitive/brainwaves via electroencephalogram (EEG) which function as a unique performance indicator due to its reliable, flexible, and unique trait resulting in why it is hard for an un-authorized entity(ies) to breach the boundaries by stealing or mimicking them. Conventional security and privacy techniques in the medical domain are not the potential candidates to simultaneously provide both security and energy efficiency. Therefore, state-of-the art biometrics methods (i.e., machine learning, deep learning, etc.) their applications with novel solutions are investigated and recommended. The experimental setup considers EEG data analysis and interpretation of BCI. The key purpose of this setup is to reduce the number of electrodes and hence the computational power of the Random Forest (RF) classifier while testing EEG data. The performance of the random forest classifier was based on EEG datasets for 20 subjects. We found that the total number of occurred events revealed 96.1% precision in terms of chosen events.
Topics: Biometric Identification; Biometry; Cognition; Delivery of Health Care; Humans; Privacy
PubMed: 35336276
DOI: 10.3390/s22062101 -
Indian Journal of Ophthalmology Jan 2024High-precision biometry and accurate intraocular lens (IOL) power calculation have become essential components of cataract surgery. In clinical practice, IOL power... (Review)
Review
High-precision biometry and accurate intraocular lens (IOL) power calculation have become essential components of cataract surgery. In clinical practice, IOL power calculation involves measuring parameters such as corneal power and axial length and then applying a power calculation formula. The importance of posterior corneal curvature in determining the true power of the cornea is increasingly being recognized, and newer investigative modalities that can estimate both the anterior and posterior corneal power are becoming the standard of care. Optical biometry, especially using swept-source biometers, with an accuracy of 0.01-0.02 mm, has become the state-of-the-art method in biometry. With the evolution of IOL formulas, the ultimate goal of achieving a given target refraction has also moved closer to accuracy. However, despite these technological efforts to standardize and calibrate methods of IOL power calculation, achieving a mean absolute error of zero for every patient undergoing cataract surgery may not be possible. This is due to inherent consistent bias and systematic errors in the measurement devices, IOL formulas, and the individual bias of the surgeon. Optimization and personalization of lens constants allow for the incorporation of these systematic errors as well as individual bias, thereby further improving IOL power prediction accuracy. Our review provides a comprehensive overview of parameters for accurate biometry, along with considerations to enhance IOL power prediction accuracy through optimization and personalization. We conducted a detailed search in PubMed and Google Scholar by using a combination of MeSH terms and specific keywords such as "ocular biometry," "IOL power calculations," "prediction accuracy of refractive outcome in cataract surgery," "effective lens position," "intraocular lens calculation formulas," and "optimization of A-constants" to find relevant literature. We identified and analyzed 121 relevant articles, and their findings were included.
Topics: Humans; Lens Implantation, Intraocular; Phacoemulsification; Refraction, Ocular; Lenses, Intraocular; Biometry; Cornea; Cataract; Retrospective Studies; Optics and Photonics
PubMed: 38131567
DOI: 10.4103/IJO.IJO_1219_23 -
Biometrical Journal. Biometrische... Sep 2019Clinical trials with adaptive sample size reassessment based on an unblinded analysis of interim results are perhaps the most popular class of adaptive designs (see...
Clinical trials with adaptive sample size reassessment based on an unblinded analysis of interim results are perhaps the most popular class of adaptive designs (see Elsäßer et al., 2007). Such trials are typically designed by prespecifying a zone for the interim test statistic, termed the promising zone, along with a decision rule for increasing the sample size within that zone. Mehta and Pocock (2011) provided some examples of promising zone designs and discussed several procedures for controlling their type-1 error. They did not, however, address how to choose the promising zone or the corresponding sample size reassessment rule, and proposed instead that the operating characteristics of alternative promising zone designs could be compared by simulation. Jennison and Turnbull (2015) developed an approach based on maximizing expected utility whereby one could evaluate alternative promising zone designs relative to a gold-standard optimal design. In this paper, we show how, by eliciting a few preferences from the trial sponsor, one can construct promising zone designs that are both intuitive and achieve the Jennison and Turnbull (2015) gold-standard for optimality.
Topics: Biometry; Clinical Trials as Topic; Humans; Pancreatic Neoplasms
PubMed: 30411405
DOI: 10.1002/bimj.201700308 -
Eye (London, England) Feb 2023We provide global averages and standard deviations for ocular biometry-axial length (AL), corneal radius of curvature (CR), anterior chamber depth (ACD), lens thickness...
BACKGROUND/OBJECTIVES
We provide global averages and standard deviations for ocular biometry-axial length (AL), corneal radius of curvature (CR), anterior chamber depth (ACD), lens thickness (LT), white to white (WTW), and central corneal thickness (CT). We hope a better understanding of normal and abnormal values will help clinicians gain further insight into their surgical outcomes, especially for off-target eyes.
SUBJECTS/METHODS
We searched the MEDLINE database using keywords "axial length, corneal power, anterior chamber depth, lens thickness, white to white, and corneal thickness." We included studies that reported averages and standard deviations on eye biometry for at least 1300 eyes. Global weighted averages and standard deviations were calculated using the Cochrane method.
RESULTS
Fourteen studies were included, originating from Asia (Japan, Singapore, Myanmar, Iran, South Korea, China), Europe (Germany, United Kingdom, Portugal), Australia, and North America (United States). Global ocular biometry metrics were: AL-23.49 mm ± 1.35 mm, CR-7.69 mm ± 0.28 mm, ACD-3.10 mm ± 0.47 mm, WTW-11.80 mm ± 0.42 mm, LT-4.37 mm ± 0.43 mm, and CT-544 μm ± 38 μm. Total eyes per value ranged from 19,538 to 90,814.
CONCLUSIONS
We report global ocular biometry averages and standard deviations. No eyes were from studies in Africa or South America, highlighting the need to publish eye biometry data from these continents. We hope that promoting a deeper understanding of biometry values will help clinicians gain insight into surgical outcomes and drive innovations in lens calculations.
Topics: Humans; Axial Length, Eye; Cornea; Lens, Crystalline; Data Collection; Biometry; Anterior Chamber; Refraction, Ocular
PubMed: 35190667
DOI: 10.1038/s41433-022-01961-3 -
Ceska a Slovenska Oftalmologie :... Feb 2014The present study compares accuracy of optical biometry (OB) and ultrasound biometry (UB) based on postoperative best corrected visual acuity (BCVA) results, and... (Comparative Study)
Comparative Study
PURPOSE
The present study compares accuracy of optical biometry (OB) and ultrasound biometry (UB) based on postoperative best corrected visual acuity (BCVA) results, and assesses the extent of the usage of the measurement methods in current practice.
METHODS
335 eyes in total were operated for cataract at Beskydské oční centrum (Beskydy Eye Centre; BOC), Frýdek-Místek hospital, in the period between 7 February 2007 and 7 April 2010. All patients were examined using both IOL-Master and Ocu-Scan prior to the surgery. All surgeries were performed using microcoaxial phacoemulsification, 2,2 mm incision, implanting IOL AcrySof SP, SPN or SPN IQ. BCVA was examined three months after the surgery. We first calculated medians of anterior-posterior axial length (AL) values measured using both methods; with both the whole set and individual subsets created according to the eye length. Difference between the two methods was calculated in mm. We calculated accurate dioptric power of the IOL, which should have been implanted in the lens bag to ensure postoperative emmetropia, using BCVA results. With each eye, we determined the size of diopter variation of the IOLs dioptric power value for emmetropia determined by an optical biometer from the accurate value of the IOLs dioptric power. Ultrasound biometry results were processed in the same way. The SRK-T formula was used for calculation with each biometry. We also calculated the number of variations above 1 D and 2 D with both biometric methods.
RESULTS
The median of axial eye length measured using an optical biometer was 23,08 mm, and the median of axial eye length measured using ultrasound biometry was 22,93 mm. The difference between these values was 0,15 mm (150 microns), which equals the difference between average values of coincident measurement results. Average variation of dioptric power of an implanted IOL from retrospectively established optimum value of the IOLs optical power was 0,40 D lower with optical biometry and 0,16 D lower with ultrasound biometry. In the context of assessing the course of the curves of both methods created using a polynomial graph, this result confirms that the two methods correspond significantly, and therefore selecting any of the methods could not negatively impact determination of the implanted IOLs dioptric power. Comparing the frequency of variations above 1D and 2,0 D with OB and UB from the accurate value of the IOLs dioptric power, we discovered a substantially higher percentage of variations with UB - up to 25 % of the total set above 1,0 D.
CONCLUSION
RESULTS of comparing accuracy and comfort of AL measurement with both methods justify unambiguous preference of optical biometry over ultrasound biometry in current practice. If measurement using ultrasound probe is done correctly, results of both methods correspond significantly, and so the methods are mutually replaceable. Using ultrasound biometry is therefore adequate in case optical biometry cannot be used.
Topics: Biometry; Female; Humans; Interferometry; Lenses, Intraocular; Male; Middle Aged; Reproducibility of Results; Visual Acuity
PubMed: 24862369
DOI: No ID Found -
Journal of Cataract and Refractive... Mar 2022To assess the repeatability and accuracy of corneal astigmatism measurement with a spectral-domain optical coherence tomography (OCT) system (Avanti, Optovue) and... (Observational Study)
Observational Study
PURPOSE
To assess the repeatability and accuracy of corneal astigmatism measurement with a spectral-domain optical coherence tomography (OCT) system (Avanti, Optovue) and compare them with Scheimpflug imaging (Pentacam HR, Oculus) and swept-source optical biometry (IOLMaster 700, Carl Zeiss Meditec AG).
SETTING
Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
DESIGN
Prospective cross-sectional observational study.
METHODS
60 pseudophakic eyes with monofocal nontoric intraocular lens that previously had refractive surgery were analyzed. To assess accuracy, simulated keratometry (SimK) and net corneal astigmatism, obtained from each device, were compared with subjective manifest refraction astigmatism. Repeatability for corneal astigmatism was assessed for OCT and Pentacam HR by the coefficient of repeatability from 3 repeated measures.
RESULTS
Compared with manifest refraction, SimK readings produced with-the-rule astigmatic bias that was reduced for net astigmatism for the 3 devices. Except for OCT net astigmatism, all instruments significantly overestimated the magnitude of the astigmatism (linear mixed-effects model [LMM], P < .05). OCT net astigmatism showed the highest accuracy for manifest astigmatism prediction with the smaller 95% confidence ellipse for the mean difference vector. OCT net mean absolute difference was 0.57 diopters (D), significantly smaller than that of the other modalities (LMM, P < .05). Net corneal astigmatism measured with OCT showed the best repeatability (coefficient of repeatability = 0.29 D).
CONCLUSIONS
OCT has the capability to measure net corneal astigmatism with higher precision and accuracy than Pentacam HR Scheimpflug imaging and IOLMaster 700 swept-source optical biometry in postrefractive subjects.
Topics: Astigmatism; Biometry; Cornea; Corneal Topography; Cross-Sectional Studies; Humans; Prospective Studies; Reproducibility of Results; Tomography, Optical Coherence
PubMed: 34326282
DOI: 10.1097/j.jcrs.0000000000000766 -
Nature Communications Nov 2023Fetal biometry and amniotic fluid volume assessments are two essential yet repetitive tasks in fetal ultrasound screening scans, aiding in the detection of potentially...
Fetal biometry and amniotic fluid volume assessments are two essential yet repetitive tasks in fetal ultrasound screening scans, aiding in the detection of potentially life-threatening conditions. However, these assessment methods can occasionally yield unreliable results. Advances in deep learning have opened up new avenues for automated measurements in fetal ultrasound, demonstrating human-level performance in various fetal ultrasound tasks. Nevertheless, the majority of these studies are retrospective in silico studies, with a limited number including African patients in their datasets. In this study we developed and prospectively assessed the performance of deep learning models for end-to-end automation of fetal biometry and amniotic fluid volume measurements. These models were trained using a newly constructed database of 172,293 de-identified Moroccan fetal ultrasound images, supplemented with publicly available datasets. the models were then tested on prospectively acquired video clips from 172 pregnant people forming a consecutive series gathered at four healthcare centers in Morocco. Our results demonstrate that the 95% limits of agreement between the models and practitioners for the studied measurements were narrower than the reported intra- and inter-observer variability among expert human sonographers for all the parameters under study. This means that these models could be deployed in clinical conditions, to alleviate time-consuming, repetitive tasks, and make fetal ultrasound more accessible in limited-resource environments.
Topics: Pregnancy; Female; Humans; Amniotic Fluid; Retrospective Studies; Deep Learning; Automation; Biometry
PubMed: 37923713
DOI: 10.1038/s41467-023-42438-5