Factors Associated With the Accuracy of Depth Gauge Measurements

Background: It is important to select appropriate screws in orthopedic surgeries, as excessively long or too short a screw may results failure of the surgeries. This study explored factors that affect the accuracy of measurements in terms of the experience of the surgeons, passage of drilled holes and different depth gauges.Methods: Holes were drilled into fresh porcine femurs with skin in three passages, straight drilling through the metaphysis, straight drilling through the diaphysis, and angled drilling through the diaphysis. Surgeons with different surgical experiences measured the holes with the same depth gauge and using a vernier caliper as gold standard. The length of selected screws, and the time each surgeon spent were recorded. The measurement accuracy was compared based on the experiences of the surgeons and the passage of drilled holes. Further, parameters of depth gauges and 12-mm cortical bone screws from five different manufacturers were measured.Results: A total of 13 surgeons participated in 585 measurements in this study, and each surgeon completed 45 measurements. For the surgeons in the senior, intermediate, and junior groups, the average time spent in measurements was 689, 833, and 785 s with an accuracy of 57.0, 42.2, and 31.5%, respectively. The accuracy and measurement efficiency were significantly different among the groups of surgeons (P < 0.001). The accuracy of measurements was 45.1% for straight metaphyseal drilling, 43.6% for straight diaphyseal drilling, and 33.3% for angled diaphyseal drilling (P = 0.036). Parameters of depth gauges and screws varied among different manufacturers.Conclusion: Both observer factor and objective factors could affect the accuracy of depth gauge measurement. Increased surgeon's experience was associated with improvements in the accuracy rate and measurement efficiency of drilled holes based on the depth gauge. The accuracy rate varied with hole passages, being the lowest for angled drilled holes.

Metrological Analysis of the Relationship Model between the Properties of Piezoelectric Materials

The properties of piezoelectric materials due to the effect of electrical, mechanical, thermal, radiation, and chemical parameters are systematized. On the basis of Maxwell's relations (obtained from expressions for thermodynamic functions) and the application of the system analysis methodology, it made it possible to develop an analytical model of the relationship between the parameters and properties of piezoelectrics in the form of a system of equations. The results of the metrological analysis of an analytical model, which made it possible to identify the sources of additional errors in the measurement of parameters, to derive formulas for their calculation, which in turn contributes to an increase in the accuracy of measurements of the piezoelectrics parameters and products based on them, are presented.

Study on the Reliability and Accuracy of Scolioscope, a New Digital Scoliometer

Early detection of scoliosis with school screening and quick, easy, and reliable assessment of its progress are of paramount importance in the management of patients. There have been several tools described, with the most common being the analog scoliometer. Most recently, smartphone applications have entered this area with and without the use of sleeves for the device. There is no research that has evaluated the accuracy of measurements both left and right in either digital or analog devices. In this study, we evaluated the reliability and validity of a new digital scoliometer called the Scolioscope. Thirty subjects were included for the intra-rater reliability study. ICC values >0.9 were calculated both for same-day and between-day measurements. The device was highly accurate with an average difference from the ones set on the sine bar of 0.03° for right-side measurements and 0.18° for the left. These measurements suggest a highly accurate and reliable tool.

Analysis of the temperature component of the combined standard uncertainty of the refractive index according to the test data of the control system for meteorological parameters developed for the Lyptsi geodetic polygon

The National Scientific Centre “Institute of Metrology” is actively involved in the implementation of a number of international projects under the EMPIR programme. One of such joint projects is the EMPIR 18SIB01 GeoMetre research project “Large-scale dimensional measurements for geodesy”. The overall goal of the project is to ensure traceability of length measurements – from the measurement standard of the unit of length to long distances typical for geodetic measurements. As a result of the project, it is necessary to provide length measurements of at least 5 km with an expanded uncertainty of no more than 1 mm. The main task of the NSC “Institute of Metrology” within this project is the development, research and practical implementation of methods and means of accounting for the influence of the earth’s atmosphere on the results of measurements of long distances in geodesy, carried out using electromagnetic waves in the optical range. When performing the section Task 1.4 of the project, new methods of highly accurate determination of the mean integral refractive index of air, used as a correction taking into account the influence of the atmosphere on the measurement results, are justified. Requirements for the accuracy of measurements of meteorological parameters at discrete points of the baseline are formulated, which are necessary to determine the mean integral refractive index. That is, the requirements for the metrological characteristics of temperature, pressure and humidity sensors are determined. The article discusses the results of the development, manufacture and testing of the sensors for temperature measurement. It is shown that the created sensors meet the requirements of the GeoMetre project.

Devising a method for measuring the motion parameters of industrial equipment in the quarry using adaptive parameters of a video sequence

The method and structural scheme of an information-measuring system for determining the parameters of objects' movements (technological equipment in the quarry for extracting block natural stone) have been proposed. A distinctive feature of time video sequences containing images of measured objects is their adaptation and adjustment in accordance with the intensity of movement and accuracy requirements for measurement results. Structural and software-algorithmic methods were also applied for improving the accuracy of measurements of motion parameters, namely: complexation of two measuring channels and exponential smoothing of digital references. One of the measuring channels is based on a digital video camera, the second is based on an accelerometer mounted on an object and two integrators. Exponential smoothing makes it possible to take into consideration the previous countdowns of movement parameters with weight coefficients. That ensures accounting for the existing patterns of movement of the object and reducing the errors when measuring the parameters of movement by (1.4...1.6) times. The resulting solutions have been implemented in the form of an information and measurement system. The technological process of extracting blocks of natural stone in the quarry was experimentally investigated using a diamond-rope installation. Based on the contactless measurement of motion parameters, it is possible to ensure control over this process and improve the quality of blocks made of natural stone. Based on the experimental study of measurement errors, recommendations were given for the selection of adaptive parameters of a video sequence, namely the size of images and the value of the inter-frame interval. In addition, methods for the software-algorithmic processing of measuring information were selected, specifically exponential smoothing and averaging the coordinates of the contour of an object, measured in 30 adjacent lines of the image

The prospect of using Shewhart control charts in assessing the quality of ionometric measurements by the method of adding a sample to a standard

Modern methods of quantitative physical and chemical measurements should necessarily include procedures for quality control of research results. Recently, the procedure for quality control of measurements using control charts is gaining particular popularity in the practice of analytical measurements. To date, the methods of potentiometric studies operating in the territory of the Russian Federation, in most cases, do not include quality control using this control procedure. However, despite the complexity of the implementation and interpretation of its results, it is the use of control charts that allows you to control the quality of ionometric measurements. This is especially important for potentiometric determinations based on the addition method, since the instability of the slope of the electrode function and its deviation significantly contribute to the uncertainty of the measurement results. This article presents the main results of evaluating the use of the Shewhart control chart method for monitoring the repeatability and accuracy of measurement results. The measurement results have been obtained using an improved method of quantitative potentiometric determination of high concentrations (more than 1 gm/cdm) of ammonium ions by the method of adding a sample to the standard. In addition, an experimental substantiation of the fact that the value of the slope of the electrode function significantly affects the accuracy of measurements by the addition method has been presented. It has been revealed that when the angular coefficient of the electrode function is more than 62 mV/pNH4+ at (25±5)°C, deviations of the measurement results from the control standard by more than 50% are observed. It has been found that at (25±5)°С the most accurate results of quantitative determination are achieved when the angular coefficient of the electrode function is from 54 mV/pNH4+ to 62 mV/pNH4+ inclusive.

Practicality of Wound Detection Using Smartphone Measure App

The record of the pressure sore with photo needs to be measurable. We compare the time consumption of wound assessment ruler and measure application of smartphone and the satisfaction of the users. The time needed is 20 and 35 seconds for the ruler and the application on average. But the satisfaction is better for application for its convenience, less infection, and the accuracy of measurements.

Method of enthalpy calibration for differential scanning calorimeters

The article describes a new method for enthalpy calibration of differential scanning calorimeters. The method allows you to remove the limitation on the temperature range in which this metrological procedure can be carried out. The proposed method does not require the use of standard samples of heats of fusion, therefore, it is not limited by the thermophysical properties of the certified substances. The developed method solves the problem of increasing the accuracy of measurements of specific enthalpy and heats of phase transitions of various substances for all types of differential scanning calorimeters. The effectiveness of the method in solving this problem is confirmed and illustrated by the authors by comparing the results of measuring the heats of fusion of a number of metals. The results obtained on differential scanning calorimeters calibrated by the new method and on the same instruments, but calibrated in accordance with the generally accepted standardized method of the International Union of Theoretical and Applied Chemistry, were compared. The authors experimentally revealed the advantages of the new method in terms of saving time and money required for calibration. The article will be of interest to those specialists who use differential scanning calorimeters in the development of new materials, control of technological processes, production, input and output control, as well as to those specialists who develop methods for research and measurement of various materials on differential scanning calorimeters.

A Comparison of the Accuracy of WATCHMAN and WATCHMAN FLX Device Sizing between CT, TEE, and Patient Specific 3D Models

Background and Hypothesis: In patients with Atrial fibrillation (AF), the Left Atrial Appendage (LAA) is the most common site of thrombus formation. The LAA occlusion procedure using the WATCHMAN device implant is an alternative for stroke prevention in AF patients. Transesophageal echocardiogram (TEE) and Computed tomography (CT) scans aid in measuring the LAA to predict implant device sizes. However, due to varying LAA anatomy and limited spatial resolution, the current imaging techniques often predict one of two sized devices. The objective of this retrospective study is to compare the accuracy of measurements made preoperatively of the LAA with those on 3D models to determine if they can be used in preoperative planning. We hypothesize 3D models will be more accurate in predicting device size and any anatomical impediments than traditional TEE planning. Project Methods: There were 21 subjects selected who underwent the WATCHMAN FLX procedure at Parkview Heart Institute in 2021. 3D models of LAA were created from CT scans using a Form 2 3D printer. The device sizes predicted for the procedure were determined from Boston Scientific FLX guidelines based on the maximum LAA orifice diameter from TEE, CT, and 3D models. Results: Two-proportion z-test between the 3D model predicted sizes to the actual size deployed demonstrated no statistical significance (p=0.298) demonstrating no difference between 3D model predicted sizes and actual size deployed. Two-proportion z-test between TEE vs actual size and CT vs actual size demonstrated statistical significance, suggesting a difference between the group's predictions. 3D models predicted the accurate device size for 20/21(95%) subjects. TEE measurements of maximum orifice diameter were, on average, lower compared to CT and 3D model measurements. Conclusion and Potential Impact: 3D printed models provide the most accurate device size predictions and can be used to optimize presurgical planning while reducing intraoperative complications.