System Accuracy Evaluation Research Articles

Accurate urine sodium measurements at home using Point of Care Testing in patients with Short Bowel Syndrome.

Measurement of the urine sodium concentration (USC) is a simple procedure that in many patients adequately indicates their hydration status. This is of particular importance in patients suffering from short bowel syndrome (SBS), who may very rapidly dehydrate and are at risk for permanently compromising their kidney function. A point of care test (POCT) that allows reliable measurement of USC would enable these patients to effectively evaluate their sodium- and water balance in the at home setting, thereby avoiding hospital visits and delayed test results. In this study, a POCT device to assess USC was first analytically validated after which it was applied for the at home evaluation of the hydration status in patients with SBS. First, we validated the imprecision, bias and limit of quantification of USC as measured with the Fisic Medimate POCT device in comparison to an automated routine chemistry system. Next, the device was used for monitoring USC at home in 21 patients with SBS, including an evaluation of user friendliness System Usability Scale (SUS) and accuracy for detecting low sodium levels as compared to the routine chemistry system. The imprecision of the POCT device at low USC was 6.1 %. In samples at the clinical decision threshold to identify patients at the verge of dehydration of 20 mmol/l as measured by routine chemistry USC, the POCT device demonstrated a mean estimation of USC of 20.6 mmol/l (95% CI 18.8-22.4). Dehydration was detected with a sensitivity of 95% when the medical decision limit for urinary sodium on the POCT device was set at a safe concentration of 30 mmol/l. Using the device was straightforward and easy to learn for patients with an overall System Usability Scale (SUS) score of 86. USC measurements using this POCT device can be safely integrated into daily practice for early detection of dehydration in patients with SBS. Clear patient instructions to ensure accurate drop dispensing and a higher clinical decision threshold of USC of 30 mmol/l will allow a high sensitivity for detecting dehydration in patients with short bowel syndrome.

Accuracy Evaluation Method for Vector Data Based on Hexagonal Discrete Global Grid

With the continuous advancement of technology for obtaining geographic spatial data, the accumulated volume of such data has been increasing, thus imposing higher demands on the storage, organization, and management of such data. As a new form of data management, the Discrete Global Grid System (DGGS) provides standardized descriptions and the exchange of geographic information on a global scale, enabling the efficient storage and application of large-scale global spatial data. Constituting a traditional type of GIS spatial data, vector data have advantages such as clear positions, implicit attributes, and suitability for map output. The representation of vector data in the global discrete grid network based on an equal-area projection, such as the hexagonal grid, fundamentally solves problems such as data redundancy, geometric deformation, and data discontinuity that arise when representing multiple vector data in a gridded format. This paper proposes different gridding methods for various types of vector data, and a quantifiable accuracy evaluation system is established from the perspectives of geographical deviation, geometric features, and topological relationships, to evaluate the accuracy of the gridded vector data, covering all types of gridded vector data based on the hexagonal grid. The evaluation method is generally applicable to all hexagonal-grid-based gridded vector data, and can be generalized based on application scenarios, for evaluating the usability of hexagonal grid vector data.

Real-Time Accuracy Evaluation of Arterial Catheter Transducer Systems

IntroductionArterial pressure is currently monitored in ICU with a catheter–transducer fluid line. This fluid filled tubing line distorts the original waveform due to its dynamic characteristics (natural frequency, Fn, and damping coefficient, z), introducing potentially significant errors when calculating the cardiac output from pulse contour signal analysis. MethodsIn our study, we cross-compared Fn and z obtained with our new Fast External Pressure Test (FEPT) and with the Fast Flush Test (FFLT), to the reference technique (Sine wave variable Frequency Analysis Test - SFAT). It was carried on a testbench for 48 hours. Fn and z were measured using the three techniques with two fluid-filled tubing lines (standard, STD, and blood conserving device, BCD). ResultsFn measurements with FEPT and FFLT present similar biases (0.79 vs 0.83 Hz), but lower variability for FEPT, with limits of agreement (LOA) ranging from −3.35 to +4.99 Hz for FFLT vs −2.29 to +3.86 Hz (p<0.0001) for FEPT. For the measurement of z, FEPT has a bias of 0.047 and LOA of −0.063 to +0.157, much lower (p<0.0001) than those measured with the FFLT (bias 0.139 and LOA −0.028 to +0.306). ConclusionWhen automated, the FEPT method will detect potential situations of over/under estimations occurrences. This will prevent false alarms, alarm fatigue and therefore consequences on patient care. Eventually, FEPT turns to be more accurate than FFLT, less scattered, less time-consuming, less invasive and so well suited for use in clinical settings.

A high-accuracy system model and accuracy evaluation method for transfer alignment

With the increasing demand for high-accuracy navigation, distributed payloads put forward higher requirements for the initial alignment accuracy of their equipped slave inertial navigation systems (INSs). However, the existing transfer alignment models have poor compensation effect on flexible deformation, resulting in low alignment accuracy. Moreover, these models cannot accurately evaluate the accuracy of transfer alignment due to ignoring the errors of the master INS. To address these two problems, a new high-accuracy transfer alignment system model is established by comprehensively considering errors of the master and slave INSs. Further, the propagation characteristics of the master and slave inertial sensor errors in transfer alignment are analyzed, and the relationship expression between the master and slave inertial sensor accuracy and the transfer alignment accuracy is derived. Thus, the accuracy of transfer alignment can be pre-evaluated according to the master and slave inertial sensor accuracy. The experiment results show that the alignment accuracy of the proposed method is improved by more than 71.56% compared with the traditional methods, and the relative errors between the proposed accuracy evaluation method and the Monte Carlo simulations are less than 9.14%. Thus, the correctness, effectiveness and superiority of the proposed method are verified.

Evaluation of 3D Markerless Motion Capture System Accuracy during Skate Skiing on a Treadmill.

In this study, we developed a deep learning-based 3D markerless motion capture system for skate skiing on a treadmill and evaluated its accuracy against marker-based motion capture during G1 and G3 skating techniques. Participants performed roller skiing trials on a skiing treadmill. Trials were recorded with two synchronized video cameras (100 Hz). We then trained a custom model using DeepLabCut, and the skiing movements were analyzed using both DeepLabCut-based markerless motion capture and marker-based motion capture systems. We statistically compared joint centers and joint vector angles between the methods. The results demonstrated a high level of agreement for joint vector angles, with mean differences ranging from -2.47° to 3.69°. For joint center positions and toe placements, mean differences ranged from 24.0 to 40.8 mm. This level of accuracy suggests that our markerless approach could be useful as a skiing coaching tool. The method presents interesting opportunities for capturing and extracting value from large amounts of data without the need for markers attached to the skier and expensive cameras.

System Accuracy and Interference Evaluation of a New Glucose Dehydrogenase-Based Blood Glucose Meter for Patient Self-Testing.

New European medical device regulations require the performance of postmarketing surveillance evaluations for blood glucose meters (BGMs). We conducted an ISO15197:2015-conform system performance evaluation with the approved glucose dehydrogenase (GDH)-based Wellion NEWTON BGM. One hundred subjects were enrolled into the study (44 female, 56 male, 43 healthy subjects, 23 type 1 diabetes, 34 type 2 diabetes, age: 53.7 ± 15.8 years). In addition, manipulated heparinized whole blood was used for a laboratory interference test with ten selected substances (interference definition: substance-induced bias > 10%). The mean absolute relative difference (MARD) was 4.7%, and 100% of the values were in zones A (99.7%) and B (0.3%), respectively, of the consensus error grid. Interference was observed with xylose only, which is a known interfering substance for GDH-based BGMs.

Evaluation of treatment planning system accuracy in estimating the stopping‐power ratio of immobilization devices for proton therapy

To assess treatment planning system (TPS) accuracy in estimating the stopping-power ratio (SPR) of immobilization devices commonly used in proton therapy and to evaluate the dosimetric effect of SPR estimation error for a set of clinical treatment plans. Computed tomography scans of selected clinical immobilization devices were acquired. Then, the water-equivalent thickness (WET) and SPR values of these devices based on the scans were estimated in a commercial TPS. The reference SPR of each device was measured using a multilayer ion chamber (MLIC), and the differences between measured and TPS-estimated SPRs were calculated. These findings were utilized to calculate corrected dose distributions of 15 clinical proton plans for three treatment sites: extremity, abdomen, and head-and-neck. The original and corrected dose distributions were compared using a set of target and organs-at-risk (OARs) dose-volume histogram (DVH) parameters. On average, the TPS-estimated SPR was 19.5% lower (range, -35.1% to 0.2%) than the MLIC-measured SPR. Due to the relatively low density of most immobilization devices used, the WET error was typically <1mm, but up to 2.2mm in certain devices. Overriding the SPR of the immobilization devices to the measured values did not result in significant changes in the DVH metrics of targets and most OARs. However, some critical OARs showed noticeable changes of up to 6.7% in maximum dose. The TPS tends to underestimate the SPR of selected proton immobilization devices by an average of about 20%, but this does not induce major WET errors because of the low density of the devices. The dosimetric effect of this SPR error was negligible for most treatment sites, although the maximum dose of a few OARs exhibited noticeable variations.

Research on accuracy of field patrol data based on GIS

Field patrol is the main method of wildlife protection, which plays a very important role in the protection and management of natural resources and biodiversity in nature reserves. However, it is difficult to completely evaluate the patrol accuracy, because it is impossible to preset the animal site in advance. Based on patrol data collected from the First Ecological Guard Competition, the accuracy of patrol route, animal site and geographical factor of animal site and GIS method are evaluated and analyzed. The results show that: (1) the patrol route has the highest accuracy, and the average accuracy is 87.91%, which indicates that ranger could basically patrol according to the preset patrol route; (2) the accuracy of animal site is not as good as that of patrol route, and the average accuracy is 51.10%, mainly because recorded animals are not right, standardized and complete; (3) the altitude accuracy is high, the slope accuracy is very low. It is recommended that slope data would no longer be recorded in the future and be directly obtained by GIS method. The results are helpful to improve the patrol accuracy evaluation system.

A Precision Evaluation Index System for Remote Sensing Data Sampling Based on Hexagonal Discrete Grids

With the rapid development of earth observation, satellite navigation, mobile communication, and other technologies, the order of magnitude of the spatial data we acquire and accumulate is increasing, and higher requirements are put forward for the application and storage of spatial data. As a new form of data management, the global discrete grid can be used for the efficient storage and application of large-scale global spatial data, which is a digital multiresolution georeference model that helps to establish a new model of data association and fusion. It is expected to make up for the shortcomings in the organization, processing, and application of current spatial data. There are different types of grid systems according to the grid division form, including global discrete grids with equal latitude and longitude, global discrete grids with variable latitude and longitude, and global discrete grids based on regular polyhedrons. However, there is no accuracy evaluation index system for remote sensing images expressed on the global discrete grid to solve this problem. This paper is dedicated to finding a suitable way to express remote sensing data on discrete grids, as well as establishing a suitable accuracy evaluation system for modeling remote sensing data based on hexagonal grids to evaluate modeling accuracy. The results show that this accuracy evaluation method can evaluate and analyze remote sensing data based on hexagonal grids from multiple levels, and the comprehensive similarity coefficient of the images before and after conversion is greater than 98%, which further proves the availability of the hexagonal-grid-based remote sensing data of remote sensing images. This evaluation method is generally applicable to all raster remote sensing images based on hexagonal grids, and it can be used to evaluate the availability of hexagonal grid images.

The Feasibility of Assessing the Cortical Bone Trajectory Screw Placement Accuracy Using a Traditional Pedicle Screw Insertion Evaluation System.

This was a retrospective observational study. We aimed to characterize the feasibility of assessing the accuracy of cortical bone trajectory (CBT) screw placement in midline lumbar interbody fusion using a traditional pedicle screw insertion accuracy evaluation system based on computed tomography (CT). Since Santoni and colleagues proposed CBT as an alternative approach for the treatment of lumbar degenerative disease, CBT has been biomechanically and clinically investigated in detail. The reported misplacement rate was 0%-12.5%. Therefore, these cortical screws may result in severe complications, such as nerve root, vascular, and spinal cord injuries. However, to the best of our knowledge, the accuracy of the current assessment system of cortical bone screw placement has not been described clearly. Overall, 342 cortical screws of 69 consecutive patients with lumbar degenerative disease who underwent midline lumbar interbody fusion surgery in one surgeon's initial phase were examined retrospectively. A comprehensive and detailed pedicle screw accuracy classification and grading system was introduced in our study, including 5 types of misplacement: (1) medial and (2) lateral cortical bone perforation (MCP and LCP) of the corresponding pedicle, (3) anterior cortical bone perforation of the vertebral body, (4) endplate perforation, and (5) foraminal perforation (FP). The degree of interobserver and intraobserver agreement with regard to the screw positions based on CT were used as indicators of the reliability of the modified classification system. All patients were retrospectively assessed for screw placement-related complications throughout the entire treatment course to evaluate the relationship between the procedure adequacy and neurological symptoms. The interobserver and intraobserver agreements were substantial-to-almost perfect (κ=0.78 and 0.88, respectively) in distinguishing the acceptable-placed pedicle screws from those with partial or complete cortical perforation. In the MCP and LCP-the most common types of misplacement-the interobserver agreement was substantial (κ=0.70 and 0.76, respectively), and the intraobserver agreement was almost perfect (κ=0.85 and 0.89, respectively). In total, there are 7 (2.05%) MCP and 65 (19.01%) LCP screws. The screw placement-related complication rate is significantly higher in the MCP and FP groups than that in the LCP group. Our study demonstrated that using a pedicle screw classification and grading system based on CT to assess the accuracy of CBT screw placement is feasible and practical. MCP and FP screws are more likely to cause neurological deficits with statistical significance, especially grade 2 MCP. We recommend inexperienced surgeons choose a lateral trajectory rather than a medial one if they cannot ensure accurate screw insertion. Level III.

Generation of crustal movement correction parameter considering valid period and accuracy guarantee

In recent years, due to the development of precise point positioning (PPP), the inconsistency of map and satellite positioning results due to crustal deformation has come to the surface. In order to solve this problem, a parameter for correcting the crustal deformation is necessary, and if it is provided as a service, the validity period and the accuracy guarantee are also necessary. In this research, we considered the validity period of parameters and the estimation method of the coordinates used for calculating the amount of crustal deformation and actually constructed the crustal movement correction parameter generation system and accuracy evaluation system. The parameters generated by this method are called semi-dynamic reduction (SD/R) parameters. As a result of evaluating the accuracy of SD/R parameters, we achieved a target accuracy of 4 cm at 98.3% verification points in the horizontal direction. Therefore, the effectiveness of the proposed method was shown.

System accuracy evaluation of the systems for selfmonitoring of blood glucose GL50 evo and GL 44 following DIN EN ISO 15197:2015 – A comparison of accuracy in hypo (&lt;70 mg/dL)- and hyper glycemic (≥180 mg/dL) glucose ranges

System accuracy evaluation of the systems for selfmonitoring of blood glucose GL50 evo and GL 44 following DIN EN ISO 15197:2015 – A comparison of accuracy in hypo (&lt;70 mg/dL)- and hyper glycemic (≥180 mg/dL) glucose ranges

System accuracy evaluation of 18 CE-marked current-generation blood glucose monitoring systems based on EN ISO 15197:2015

ObjectiveAccuracy of 18 current-generation blood glucose monitoring systems (BGMS) available in Europe was evaluated applying criteria adapted from EN ISO 15197:2015 with one reagent system lot. BGMS were selected based...

Kinematics parameter identification and accuracy evaluation method for neurosurgical robot

The kinematic model parameter deviation is the main factor affecting the positioning accuracy of neurosurgical robots. To obtain more realistic kinematic model parameters, this paper proposes an automatic parameters identification and accuracy evaluation method. First, an identification equation contains all robot kinematics parameter was established. Second, a multiple-pivot strategy was proposed to find the relationship between end-effector and tracking marker. Then, the relative distance error and the inverse kinematic coincidence error were designed to evaluate the identification accuracy. Finally, an automatic robot parameter identification and accuracy evaluation system were developed. We tested our method on both laboratory prototypes and real neurosurgical robots. The results show that this method can realize the neurosurgical robot kinematics model parameters identification and evaluation stably and quickly. Using the identified parameters to control the robot can reduce the robot relative distance error by 33.96% and the inverse kinematics consistency error by 67.30%.

System accuracy evaluation of the systems for self-monitoring of blood glucose GL50 evo and GL 44 following DIN EN ISO 15197:2015: A comparison of accuracy in glucose concentration ranges &lt;100 mg/dL and ≥100 mg/dL

System accuracy evaluation of the systems for self-monitoring of blood glucose GL50 evo and GL 44 following DIN EN ISO 15197:2015: A comparison of accuracy in glucose concentration ranges &lt;100 mg/dL and ≥100 mg/dL

Noninvasive Tissue Glucose Prediction in Patients with Type 1 Diabetes

Background: Pain-free assessment of the glucose information required for treatment monitoring is one of the most desired unmet medical needs in insulin treated patients with type 1 diabetes. TensorTip CoG, is a non-invasive tissue glucose monitoring device (NI-CoG) with an additional built-in invasive glucose meter (Inv-CoG), which operates based on optical methods in the near-infrared and visible wavelength range. Here we report about the results obtained from type 1 patients in the course of two clinical studies. Methods: The data from 6 patients with type 1 diabetes (3 male/3 female, age: 43±16 years, HbA1c: 8.0±0.5%), who had participated in a standard meal study experiment, and the results from 29 type 1 patients, who had participated in a system accuracy evaluation in accordance with ISO15197:2015 (13 male/16 female, age: 42±14 years, HbA1c: 7.5±0.5%) were combined for this analysis. Results: The meal study patients (n = 66 data points) and the ISO study patients (n = 29) showed good agreement of the NI-CoG predicted tissue glucose with the capillary reference method (YSI Stat2300 plus). Mean absolute relative difference (values &amp;gt;100 mg/dL) was calculated to be 13.3% (mean absolute difference for values&amp;lt;100 mg/dL: 16 mg/dL). The consensus error grid (version for type 1 diabetes) revealed 78% of the data points to be in zone A (B: 18%, C: 4%). Zone C values were only observed in patients without proper device calibration over the entire measurement range of the device. Conclusions: The results of this new non-invasive glucose prediction device are encouraging for routine use in patients with type type 1 diabetes. This non-invasive technology has reached an accuracy level for glucose prediction that is comparable to the results published for needle sensors working for flash or continuous glucose monitoring. Disclosure A. Pfützner: Advisory Panel; Self; Novo Nordisk A/S, Sanofi. Consultant; Self; Lifecare. Speaker's Bureau; Self; Berlin-Chemie AG. Research Support; Self; Boehringer Ingelheim GmbH. F. Demircik: None. A. Lier: None. S. Ramljak: None.

Evaluation Method for Ship Hull Plates’ Process Molding

The evaluation procedure is an important step for the ship hull plates automatic processing, which serves as a basis for secondary processing. In this paper, an evaluation method was proposed, based on the experienced workers' knowledge. The design surface and the measured surface were registered by transforming to the new coordinate system. Then the profile errors were evaluated and decomposed into three directions: transverse, longitudinal, and torsional. Finally, the experiment results shown that the evaluation indexes, which were based on the errors decomposed result, can be served as the basis for secondary processing of the ship hull plates. 1. Introduction Ship hull plates are thick large steel plates with arbitrary threedimensional (3D) shapes. Usually, the steel plates are plastically deformed to the design shape by line heating process. And the shapes of the machining plates are evaluated by the wooden bending templates, which are generated by ship's design data. Experienced workers can evaluate the transverse bending, longitudinal bending, as well as torsional angle of the plates by this process, and get the essential factual basis for the secondary processing. However, this process has no clear-cut methodology, the evaluation results and the secondary processing plan are heavy, depending on the tacit knowledge, skill, and experience of the craftsmen during the line heating processing (Woo-Jae et al. 2010; Hiekata et al. 2011; Seong et al. 2013; Sun et al. 2013). For ship hull plates profile error evaluation, Hiekata et al. (2011) had put forward an accuracy evaluation system, using 3D laser scanner to measure the ship hull plates, and then evaluated the displacement errors by comparing the measured surface with the design surface. This system had achieved digital evaluation, but the evaluation indexes were difficult to guide the secondary processing. Sun et al. (2013) evaluated the ship hull plates by the virtual templates, and generated the processing plan, according to the evaluation results. Nevertheless, this method only evaluates the longitudinal bending and torsional condition. it still needs to be improved. Also, other researchers (Wen et al. 2013; Liu 2014; He et al. 2015; Nasri et al. 2015) had put forward various evaluation methods, but the purposed methods were aimed to improve the evaluation accuracy, seldom consider the line heating process. Thus, these methods have failed to provide the factual basis for the secondary processing.

Novel accuracy test for multispectral imaging systems based on \u0394E measurements

In the printing industry, multispectral line scan cameras are being applied with increasing frequency in print inspection. This field of application requires highly accurate camera systems. In this article, we describe a novel approach to determining the accuracy of multispectral measurements recorded by line scan cameras. The approach is based on Bayesian statistics and paves the way for inline applications. Our approach uses the distribution of color distances, as expressed by ΔE values, that arise when the reference color spectra of a color chart are compared with corresponding spectra reconstructed from the measured camera responses of observed color patches. By means of 18 ΔE values originating from a color control strip, our approach provides an accuracy evaluation of multispectral imaging systems with line scan technology. To demonstrate this, four scenarios are considered in which the multispectral imaging system is used with different measurement accuracies. It is shown that the imaging system in these cases can be reliably characterized with respect to the quality of the multispectral measurements.

System Accuracy and User Performance Evaluation of an Improved System for Self-Monitoring of Blood Glucose.

An improved test cassette for the integrated Accu-Chek® Mobile system (Roche Diabetes Care GmbH, Mannheim, Germany) has been developed. System accuracy of this improved system was evaluated based on ISO 15197:2013, clause 6.3, for three reagent system lots. According to this standard, at least 95% of the system's measurement results shall be within ±15 mg/dL and ±15% of the results of the comparison method at glucose concentrations <100 mg/dL and ≥100 mg/dL (accuracy criterion A), respectively, and at least 99% of results shall be within consensus error grid zones A and B (accuracy criterion B). In addition, accuracy was evaluated in the hands of users based on ISO 15197:2013, clause 8, with one reagent system lot.

マルチコプタの自律飛行の精度評価システムの開発

マルチコプタの自律飛行の精度評価システムの開発