Automatic Measurement Techniques Research Articles

From 2D to 3D: automatic measurement of the Cobb angle in adolescent idiopathic scoliosis with the weight-bearing 3D imaging

Background contextAdolescent idiopathic scoliosis (AIS) necessitates accurate spinal curvature assessment for effective clinical management. Traditional two-dimensional (2D) Cobb angle measurements have been the standard, but the emergence of three-dimensional (3D) automatic measurement techniques, such as those using weight-bearing 3D imaging (WR3D), presents an opportunity to enhance the accuracy and comprehensiveness of AIS evaluation. PurposeThis study aimed to compare traditional 2D Cobb angle measurements with 3D automatic measurements utilizing the WR3D imaging technique in patients with AIS. Study design/settingA cohort of 53 AIS patients was recruited, encompassing 88 spinal curves, for comparative analysis. Patient sampleThe patient sample consisted of 53 individuals diagnosed with AIS. Outcome measuresCobb angles were calculated using the conventional 2D method and three different 3D methods: the Analytical Method (AM), the Plane Intersecting Method (PIM), and the Plane Projection Method (PPM). MethodsThe 2D cobb angle was manually measured by 3 experienced clinicians with 2D frontal whole-spine radiographs. For 3D cobb angle measurements, the spine and femoral heads were segmented from the WR3D images using a 3D-UNet deep-learning model, and the automatic calculations of the angles were performed with the 3D slicer software. ResultsAM and PIM estimates were found to be significantly larger than 2D measurements. Conversely, PPM results showed no statistical difference compared to the 2D method. These findings were consistent in a subgroup analysis based on 2D Cobb angles. ConclusionEach 3D measurement method provides a unique assessment of spinal curvature, with PPM offering values closely resembling 2D measurements, while AM and PIM yield larger estimations. The utilization of WR3D technology alongside deep learning segmentation ensures accuracy and efficiency in comparative analyses. However, additional studies, particularly involving patients with severe curves, are required to validate and expand on these results. This study emphasizes the importance of selecting an appropriate measurement method considering the imaging modality and clinical context when assessing AIS, and it also underlines the need for continuous refinement of these techniques for optimal use in clinical decision-making and patient management.

Modernising the control network for determining displacements in hydraulic structures using automatic measurement techniques

Modernising the control network for determining displacements in hydraulic structures using automatic measurement techniques

The use of automatic measurement techniques in the geotechnical monitoring system of PGE GiEK S.A., KWB Turów branch

Geotechnical monitoring currently plays a key role in the research of the processes taking place in the ground medium and preventing hazardous events. In the case of open-pit mining, several solutions are commonly used to monitor various geotechnical parameters. However, geotechnical situation is usually assessed based on recorded values of deep and surface displacement, which allow to accurately predict landslides. The measurements are most often carried out manually, which, due to the difficult terrain conditions in the case of open-pit mining, are often timeconsuming and complicated, especially taking into account dangerous landslide movements. Therefore, in order to ensure a higher degree of safety against the risk of landslides, modern solutions are required in the field of geotechnical monitoring. This article presents modern automatic measurement techniques, compares various solutions available on the market and illustrates the benefits of their application in open-pit mining. It also discusses the expansion and modernization of the control and measurement network at KWB Turów, carried out in recent years, as well as the observational method for controlling the efficiency of stackers, developed after the installation of automated measuring stations, with its impact on the geotechnical safety of an internal waste heap. The paper as a case study presents, what a modern and effective geotechnical monitoring system should look like, which in practice will ensure continuous observation of selected parameters and enable a quick response in the event of a landslide threat. Last but not least, the author focuses on the creation of an innovative landslide early warning system, implemented at KWB Turów.

Characterizing and Modeling Smoking Behavior Using Automatic Smoking Event Detection and Mobile Surveys in Naturalistic Environments: Observational Study.

BackgroundThere are 1.1 billion smokers worldwide, and each year, more than 8 million die prematurely because of cigarette smoking. More than half of current smokers make a serious quit every year. Nonetheless, 90% of unaided quitters relapse within the first 4 weeks of quitting due to the lack of limited access to cost-effective and efficient smoking cessation tools in their daily lives.ObjectiveThis study aims to enable quantified monitoring of ambulatory smoking behavior 24/7 in real life by using continuous and automatic measurement techniques and identifying and characterizing smoking patterns using longitudinal contextual signals. This work also intends to provide guidance and insights into the design and deployment of technology-enabled smoking cessation applications in naturalistic environments.MethodsA 4-week observational study consisting of 46 smokers was conducted in both working and personal life environments. An electric lighter and a smartphone with an experimental app were used to track smoking events and acquire concurrent contextual signals. In addition, the app was used to prompt smoking-contingent ecological momentary assessment (EMA) surveys. The smoking rate was assessed based on the timestamps of smoking and linked statistically to demographics, time, and EMA surveys. A Poisson mixed-effects model to predict smoking rate in 1-hour windows was developed to assess the contribution of each predictor.ResultsIn total, 8639 cigarettes and 1839 EMA surveys were tracked over 902 participant days. Most smokers were found to have an inaccurate and often biased estimate of their daily smoking rate compared with the measured smoking rate. Specifically, 74% (34/46) of the smokers made more than one (mean 4.7, SD 4.2 cigarettes per day) wrong estimate, and 70% (32/46) of the smokers overestimated it. On the basis of the timestamp of the tracked smoking events, smoking rates were visualized at different hours and were found to gradually increase and peak at 6 PM in the day. In addition, a 1- to 2-hour shift in smoking patterns was observed between weekdays and weekends. When moderate and heavy smokers were compared with light smokers, their ages (P<.05), Fagerström Test of Nicotine Dependence (P=.01), craving level (P<.001), enjoyment of cigarettes (P<.001), difficulty resisting smoking (P<.001), emotional valence (P<.001), and arousal (P<.001) were all found to be significantly different. In the Poisson mixed-effects model, the number of cigarettes smoked in a 1-hour time window was highly dependent on the smoking status of an individual (P<.001) and was explained by hour (P=.02) and age (P=.005).ConclusionsThis study reported the high potential and challenges of using an electronic lighter for smoking annotation and smoking-triggered EMAs in an ambulant environment. These results also validate the techniques for smoking behavior monitoring and pave the way for the design and deployment of technology-enabled smoking cessation applications.International Registered Report Identifier (IRRID)RR2-10.1136/bmjopen-2018-028284

Measuring arterial blood pressure in humans: Auscultatory and automatic measurement techniques for human biological field studies.

Human biologists have been examining arterial blood pressure since they began studying the effects of the environment and culture on the health of diverse populations. The Korotkoff auscultatory technique with a trained observer and aneroid sphygmomanometer is the method of choice for blood pressure measurement in many bioanthropological field contexts. Korotkoff sounds (the first and fifth phases) are the preferred determinants of systolic and diastolic pressure, even in infants, children, pregnant women, and the elderly. Training of observers, positioning of individuals, and selection of cuff size are all essential for obtaining standardized measurements. Automatic electronic devices are increasingly being used for blood pressure measurement in human biological studies. The automatic monitors often use the oscillometric method for measuring pressure, but must be validated before use. The emergence of automatic ambulatory blood pressure monitors has opened another avenue of research on blood pressure in human biology, where allostasis and circadian responses to environmental change and real life behavioral challenges can be defined and evaluated, largely because there is now the ability to make multiple measurements over time and in varying contexts. Stand-alone automatic monitors can also be substituted for manual auscultated readings in field contexts, although in studies where participants measure their own pressure, education about how the devices work and protocol specifics are necessary. Finally, computer-driven plethysmographic devices that measure pressure in the finger are available to evaluate short-term reactivity to specific challenges.

A step forward parameter for the effects of transcatheter aortic valve implantation: transmural dispersion of repolarization.

We have recently reported a potential beneficial effect of transcatheter aortic valve implantation (TAVI) on reducing ventricular arrhytmias beyond relieving symptoms in patients with symptomatic severe aortic stenosis.[1] Basically, we showed a reduction in myocardial repolarization dispersion evaluated by QT dispersion (QTd) after TAVI in this population. QTd is the most frequently used non-invasive method to assess the myocardial repolarization abnormalities in many diseases in literature. It has been well known that QTd may provide prognostic data for future ventricular tachyarrhythmias and sudden death.[2]–[4] However, ‘achilles heel’ of this method is the reproducibility of QTd measurements. In general, it is low in both manual and automatic measurement techniques and inter- and intraobserver variability is especially high in manual measurements of QTd.[5],[6] This situation was chiefly caused by using insufficient quality of electrocardiography (ECG) samples to measurement of QTd. Such ECG's do not reflect the end of T wave with sufficient certainty. Therefore, using the appropriate ECG samples is essential to obtain the reliable data on myocardial dispersion abnormalities by QTd. In our study, we used only ECG samples which have high quality. And, we believe that our results are reliable and have future perspectives on the effects of TAVI beyond relieving symptoms in patients with symptomatic severe aortic stenosis. On the other hand, the notion of ‘transmural dispersion’ has emerged in early last decade and has led to a new perception on the understanding of myocardial repolarization. According to this model, it has been accepted that three layer of myocardium including endocardium, epicardium and mid myocardial M cells have different electrophysiological features which represents a repolarization heterogenity in basal situation.[7] Conditions affecting the myocardial repolarization such as heart rate, blood electrolyte status and drugs have a different effects on these myocardial layers which can increase the basal repolarization heterogenity and can cause ventricular arrhytmia. On ECG, the peak of T-wave represents the epicardial repolarization while the end of T-wave suggests the repolarization of midmyocardial M-cells. The time between the peak and end of the T wave is called ‘Tp-e interval’ and its ratio with QTd (Tp-e/QTd) were defined as indexes of transmural dispersion of repolarization which can predict life treating arrhytmias in different populations.[8],[9] We evaluated the Tp-e interval and Tp-e/QTd ratio on ECG of patients in our study group to comply with the author's suggestions. Both Tp-e interval and Tp-e/QTd ratio were significantly reduced after TAVI procedure in patients with severe aortic stenosis (80.1 ± 3.5 vs. 78.5 ± 2.6 ms; P = 0.008 and 0.20 ± 0.1 vs. 0.19 ± 0.1; P = 0.001, respectively). We agree with the authors that the results might be useful to completely reveal of effect of TAVI procedure on electrical heterogeneity of the myocardium.

Characteristics of flattening filter free beams at low monitor unit settings

Newer linear accelerators (linacs) have been equipped to deliver flattening filter free (FFF) beams. When FFF beams are used for step-and-shoot intensity-modulated radiotherapy (IMRT), the stability of delivery of small numbers of monitor units (MU) is important. The authors developed automatic measurement techniques to evaluate the stability of the dose profile, dose linearity, and consistency. Here, the authors report the performance of the Artiste™ accelerator (Siemens, Erlangen, Germany) in delivering low-MU FFF beams. A 6 MV flattened beam (6X) with 300 MU/min dose rate and FFF beams of 7 (7XU) and 11 MV (11XU), each with a 500 MU/min dose rate, were measured at 1, 2, 3, 5, 8, 10, and 20 MU settings. For the 2000 MU/min dose rate, the 7 (7XUH) and 11 MV (11XUH) beams were set at 10, 15, 20, 25, and 30 MU because of the limits of the minimum MU settings. Beams with 20 × 20 and 10 × 10 cm(2) field sizes were alternately measured ten times in intensity modulated (IM) mode, with which Siemens linacs regulate beam delivery for step-and-shoot IMRT. The in- and crossplane beam profiles were measured using a Profiler™ Model 1170 (Sun Nuclear Corporation, Melbourne, FL) in multiframe mode. The frames of 20 × 20 cm(2) beams were identified at the off-axis profile. The 6X beam profile was normalized at the central axis. The 7 and 11 MV FFF beam profiles were rescaled to set the dose at the central axis at 145% and 170%, respectively. Point doses were also measured using a Farmer-type ionization chamber and water-equivalent solid phantom to evaluate the linearity and consistency of low-MU beam delivery. The values displayed on the electrometer were recognized with a USB-type camera and read with open-source optical character recognition software. The symmetry measurements of the 6X, 7XU, and 11XU beam profiles were better than 2% for beams ≥ 2 MU and improved with increasing MU. The variations in flatness of FFF beams ≥ 2 MU were ± 5%. The standard deviation of the symmetry and flatness also decreased with increasing MU. The linearity of the 6X beam was ± 1% and ± 2% for the beams of ≥ 5 and ≥ 3 MU, respectively. The 7XU and 11XU beams of ≥ 2 MU showed linearity with ± 2% except the 7XU beam of 8 MU (+2.9%). The profiles of the FFF beams with 2000 and 500 MU/min dose rate were similar. The characteristics of low-MU beams delivered in IM mode were evaluated using an automatic measurement system developed in this study. The authors demonstrated that the profiles of FFF beams of the Artiste™ linac were highly stable, even at low MU. The linearity of dose output was also stable for beams ≥ 2 MU.