Caliper Tool Research Articles

Ocular surface parameters repeatability and agreement —A comparison between Keratograph 5M and IDRA

PurposeTo evaluate the repeatability and agreement in dry eye measurements using Oculus Keratograph 5M (K5M) and SBM Sistemi IDRA (IDRA). MethodsA total of 108 participants were enrolled and 108 eyes were evaluated. Tear meniscus height (TMH) and first and average non-invasive break-up time (NIBUT) were measured using the K5M and IDRA (order randomly assigned). TMH was measured using the built-in caliper tool while NIBUT was computed by the automatic algorithm of the instruments. ResultsThe Bland Altman plots analysis showed a good agreement between the two instruments for TMH (95 % Limits of Agreement (LoA), −0.17 to 0.16), but not the first NIBUT (95 % LoA, −8.13 to 14.79) and average NIBUT (95 % LoA, −7.89 to 10.32). The values of the first and average NIBUT measured using IDRA were significantly shorter than in K5M (difference = median (IQR) −2.75 (−6.48- −0.28)s, p < 0.001 and difference = median (IQR) −1.65 (−3.97–1.89)s, p = 0.008 respectively). The TMH (p = 0.037) and NIBUT average (p = 0.033) measured by K5M, as well as the TMH (p = 0.040) measured by IDRA, exhibited unstable measurements across the three measurement times. The remaining parameters exhibited stability with three repeated measurements. ConclusionThe NIBUT measurements are not interchangeable between IDRA and K5M, while the TMH was little difference between the two instruments. It is important to exercise caution when using different ocular surface analyzers to minimize errors in comparing multiple measurements.

Choroidal and central macular thickness before and after treatment in post fever retinitis.

To study the choroidal thickness (CT) and central macular thickness (CMT) in post-fever retinitis (PFR) and their correlation with visual acuity and treatment. A retrospective, observational study of patients presenting with PFR from 2013 to 2021 and with spectral domain optical coherence tomography (SD-OCT) (Heidelberg®, SpectralisTM, Heidelberg, Germany) images were included. The CT and CMT were measured at presentation and at the final visit. The CT was measured subfoveally and at points 2000 µm superior, inferior, medial, and lateral from the fovea using the caliper tool. Seventy-nine eyes of 65 patients were included for this study. The mean age was 39.03 (±16.00) years with female preponderance of 53.84% (n = 35). Mean follow-up duration was 30 days. Mean CT at presentation and at follow-up was 254.12 µm and 241.51 µm, respectively. CT was decreased in majority of the eyes 67.1% (n = 53) from their baseline value. Mean CMTs at presentation and final visit were 454.8 µm and 223.7 µm, respectively. Best corrected visual acuity had a positive correlation with CMT (r = 0.340; P = 0.002) and negligible correlation with CT. A significant decrease in the mean CT was noted in patients who received doxycycline either alone or in combination with a steroid as compared to those who did not receive any treatment (P < 0.001). The significance of which is unknown presently. CMT has a greater role in determining the final visual outcome than CT. CT can be reduced post-treatment with no effect on vision.

A scalable and lightweight group authentication framework for Internet of Medical Things using integrated blockchain and fog computing

The Internet of Medical Things (IoMT) is the network of medical devices, software applications, and healthcare information systems used for remote monitoring and delivery of healthcare services. Despite the several advantages of IoMT for today smart healthcare, security issues are growing due to the inadequate computation, limited storage and insufficient self-protection capabilities of IoMT devices. Authentication of IoMT devices is the main requirement to secure IoMT systems. Although, the recent authentication schemes based on tamper-proof decentralized architecture of blockchain technology are robust and enjoy a high level of security, yet they require high computation, more storage, and long authentication time. These issues lead to reduced scalability and time efficiency, which are necessary for large-scale, time-sensitive IoMT systems. To this end, this paper proposes a novel group authentication framework for IoMT Systems. The group authentication scheme is implemented through a four-phase process, including setup, registration, secret construction, and authentication. To enhance both efficiency and scalability, the proposed group authentication framework employs a combination of elliptic curve cryptography (ECC), Shamir’s secret sharing (SSS) algorithm, and blockchain-based fog computing technologies. We simulated the proposed framework through the Ethereum platform and Solidity language and its performance is evaluated using the Hyperledger Caliper tool. The simulation experiments of the proposed framework showed that the average latency of authenticating IoMT devices was 0.5 second and the throughput was 400 transactions per second. Our analysis of the proposed framework’s performance against other cutting-edge blockchain-based authentication techniques showed that it outperformed them in terms of latency and throughput. A security analysis of the proposed framework was conducted using the widely accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool. The formal and informal security analysis demonstrated that the proposed framework is secure and resistant to potential authentication-related attacks. We also noted that the average latency of the proposed framework maintains a fairly narrow range when the number of submitted transactions rises, indicating that it supports the scalability of the IoMT system.

A novel Hyperledger blockchain-enabled decentralized application for drug discovery chain management

The aim of the drug discovery process is to create a brand-new drug that is both safe and useful for treating disease in patients. The trustworthy collaboration of the organisations involved in the drug discovery process and the integrity of their contributions are essential for this process. Current drug discovery chains use centralised systems, which are susceptible to lockdown by cyberattacks. Blockchain, with its many characteristics such as accountability, immutability, integrity, privacy, and security, has the potential to be extremely useful in drug discovery chain management. The purpose of this work is to create a drug discovery framework utilizing the strengths of blockchain technology in combination with machine learning (ML). Such a system would provide a secure, efficient, and faster drug development life cycle. This study presents a novel Hyperledger fabric-based drug discovery application that empowers the permissioned organisations to upload, update, view, and verify contributions. ML is used to preprocess data and visualise features. In the proposed work, a unique identifier is assigned to each contribution asset using the secure hash algorithm (SHA-256). The proposed design also enables the regulatory authority to issue certificates proving the ownership of contributions to the contributing organisations. The blockchain ledger has been used to store the meta-data and InChIKey of drug contributions, and actual contributions are in off-chain storage. In this work, we have successfully built an end-to-end decentralised drug discovery application with a front-end interface and demonstrated chaincode algorithms. The end-to-end application is not available in any previous work. The Caliper tool has been used to investigate throughput, latency, and resource statistics. The performance and comparative analysis show that the proposed design is scalable and promising for drug discovery chain management.

Impact of endorsement policy on the performance of blockchain‐based VANET

AbstractWith the revolution in technology, VANET has emerged as a new generation of technology and used globally for intelligent traffic management systems. VANET uses a PKI‐based protocol to maintain privacy and security. Still, some crucial issues remain unresolved, like blind belief in communicated messages, lack of vehicle's interest in participation, revealing the sender vehicle's identity, and maintaining integrity. The solution to these issues will prevent vehicles from propagating fake messages while concurrently protecting the confidentiality of each involved vehicle against tracking attacks. Blockchain, a peer‐to‐peer, immutable, distributed ledger‐based technology, can be adapted as a robust solution to overcome critical challenges and make VANET more secure and reliable. This paper proposes a novel blockchain‐based VANET architecture, blockchain‐based vehicular ad‐hoc network (B‐VANET), implemented on the Hyperledger Fabric platform. B‐VANET aims to secure the network by validating road events before actually updating it on the network. For validation, the trust factor of each vehicle and their past involvement in the network is maintained. Trust factor value decides the trustworthiness of a vehicle. Based on this trust factor, a dynamic endorsement policy is designed. Endorsement policy, part of the smart contract, plays a vibrant role in Hyperledger Fabric. It decides how many and which particular peers can endorse the transaction to make it valid and add it to the ledger. Multiple possible approaches to endorsement policies are identified for B‐VANET and are analyzed using the Hyperledger Caliper tool. These approaches are evaluated for data integrity, confidentiality, and real‐time system issues. An appropriate approach for the B‐VANET system is recognized, giving the best throughput and latency in all possible scenarios. It is analyzed that compared to the worst approach, the best approach achieves an almost 15% increase in throughput and reduces latency by nearly half. We also compared the performance of B‐VANET and other approaches to show that our proposed system better meets VANET's security needs.

Deep Learning–Based Estimation of Implantable Collamer Lens Vault Using Optical Coherence Tomography

To develop and validate a deep learning neural network for automated measurement of implantable collamer lens (ICL) vault using anterior segment optical coherence tomography (AS-OCT). Cross-sectional retrospective study. Multicentric. A total of 2,647 AS-OCT anonymized eye scans were used from 139 eyes of 82 subjects who underwent ICL surgery in 3 different centers. Using transfer learning, a deep learning neural network algorithm was trained and validated for the regression task of estimating the ICL vault on the MS-39 OCT (CSO, Florence, Italy). A trained operator separately reviewed all OCT scans and measured the central vault using a built-in OCT caliper tool. The model was then separately tested on 191 AS-OCT scans. A Bland-Altman plot was constructed and the mean absolute percentage error (MAPE), the mean absolute error (MAE), the root mean squared error (RMSE), the Pearson correlation coefficient (r), and the determination coefficient (R2) were calculated to evaluate the strength and validity of the model. On the test set, the model achieved a MAPE of 3.42%, an MAE of 15.82 µm, an RMSE of 18.85 µm, a Pearson correlation coefficient r of +0.98 (P-Value < .00001), and a coefficient of determination R2 of +0.96. There was no significant difference between the vaults of the test set labeled by the technician versus those estimated by the model: 478 ± 95 µm versus 475 ± 97 µm, respectively, P-Value = 0.064). Using transfer learning, our deep learning neural network was able to accurately compute the ICL vault from AS-OCT scans, overcoming the limitations of an imbalanced dataset and limited training data. Such an algorithm can assist the postoperative assessment in ICL surgery. PRéCIS: This study develops and validates a deep learning model to accurately estimate implantable collamer lens vault on optical coherence tomography using transfer learning, convoluted neural networks, and regression.

Integrity assessment methodology of casing ovality deformation in shale gas wells

Casing deformation frequently occurs in shale gas wells during hydraulic fracturing. While the failure mechanism of casing ovality deformation is unclear due to the interweaving and compounding reasons from geological and engineering complexity. The multi-arm caliper tool can quantify the severity of casing deformation, and the spatial and temporal occurrence of casing deformations is analyzed. A finite element model of fractured shale squeezing casing is established to simulate the process of casing deformation. The simulated casing deformation is compared with logging data to validate the model with which the deformation mechanism would be revealed. Simulation results indicate that casing deformation in the Luzhou shale gas field belongs to compressive deformation. The length of casing deformation and the diameter shrinkage are local and small, and the deformation points are scattered along the horizontal well trajectory. The fracturing fluid pressure and fractured shale block generate a nonuniform load on the casing, which leads to stress yield and ovality deformation. The fluid pressure, formation degradation and cementing material are the key controlling factors to mitigate casing ovality deformation. This work provides a prompt & accurate assessment method and controlling measures for casing integrity in shale gas wells.

First Hexa-Combo Logging-While-Drilling Run in Kuwait: A Case Study

Directional wells through the 6-in. production-hole sections in the Marrat Reservoir of the Jurassic formations have traditionally required several wireline-logging and hole-conditioning runs for comprehensive petrophysical interpretation and completion design. As the planned well inclinations increase to maximize reservoir exposure and sweep efficiency, wireline deployment poses significant challenges due to the increased risk of losing the bottomhole assembly (BHA) in the hole. Over time, logging-while-drilling (LWD) tools have become preferable for the asset team, where the tools are run either in the drilling BHA or during a dedicated wiper trip after the section has been drilled to total depth (TD). Using LWD tools in this application also reduces well delivery times and costs. A comprehensive logging solution was required to drill the 6-in. reservoir section of a study well. The complex LWD string, consisting of gamma ray, resistivity, neutron porosity, azimuthal density, azimuthal sonic, and nuclear magnetic resonance (NMR) tools, was deployed on a motorized rotary steerable system (MRSS) BHA. In addition, a prototype high-resolution acoustic imaging and caliper tool, designed to be run in both water-based mud (WBM) and oil-based mud (OBM), was also included. The acquired logging data were used for enhanced formation evaluation. Fracture and borehole breakout interpretation from the image data played a key role in the successful completion design. This ultimately led to Kuwait’s first successful “hexa-combo” LWD drilling run and the country’s first LWD ultrasonic imaging tool run in OBM in this hole size, with 13.3 ppg OBM with a maximum downhole temperature of 275°F.

Effects of negative air ions (NAIs) on Leishmania major: A novel tool for treatment of zoonotic cutaneous leishmaniasis (ZCL).

BackgroundCutaneous leishmaniasis (CL) is a Neglected Tropical Disease (NTD) that causes high morbidity in the tropics and sub-tropics. Despite the remarkable advancements in the treatment of CL, the available therapeutics are far from ideal and also cause serious adverse side effects. Negative air ions (NAIs) generators are widely available for domestic and industrial uses. Several studies have reported on positive effects of NAIs therapy on human health as a non-pharmaceutical treatment for respiratory disease, allergy, or stress-related health conditions, including infectious diseases. To our knowledge, no studies have examined the effectiveness of the NAIs therapy against Leishmania parasites. The aims of this study were to investigate the effect of NAIs therapy on Leishmania major (L. major) the causative agent of CL in in vitro and in a murine model.Methodology/Principal findingsIn vitro anti-leishmanial effects of NAIs therapy were measured by parasitological methods. NAIs therapy was assessed in vivo in L. major infected BALB/c mice by measuring the footpad (FP) lesion size and parasite load using metric caliper tool and qPCR, respectively. Immune responses in treated and non-treated mice were assessed by measuring the levels of IFN-γ, IL-4, NO and arginase activity. In vitro NAIs therapy significantly decreased the viability of Leishmania promastigotes and of amastigotes cultured in macrophages, but did not affect the host cells. NAIs therapy of L. major infected BALB/c mice resulted in reduced FP lesion size, diminished parasite burden, and importantly decreased induction of IL-4 and arginase activity in the presence of NAIs. In contrast IFN-γ and NO levels were significantly enhanced. NAIs therapy significantly diminished the progression of disease compared to the control group, but was less effective than amphotericin B treatment.ConclusionsOur study shows that NAIs treatment was effective in vitro and in Leishmania-infected mice, elicited a T-helper 1 (Th1) response and increased efficient cellular immunity, resulting in a diminished parasite load. Therefore, NAIs therapy can be considered as a useful and safe tool that can contribute to clearing L. major infections without inducing toxicity in host cells. The applications and mechanisms of NAIs therapy warrant further investigation especially in humans suffering from CL.

Attribute-based access control scheme for data sharing on hyperledger fabric

With the popularization of the IoT and big data, the application value of data has become increasingly prominent. Therefore, it is particularly important to ensure the legitimate use of privacy data in the process of data sharing through access control. Traditional schemes usually use a trusted central organization to implement access control. However, a fully trusted central organization does not exist, and the access process of centralized access control is also opaque. In order to solve these problems, in this paper, we propose a decentralized attribute-based and fine-grained access control scheme for data sharing on Hyperledger Fabric. Firstly, the encrypted data is stored on the InterPlanetary File System (IPFS) and the returned hash is saved in the blockchain, by virtue of the immutability of blockchain. Secondly, a decentralized fine-grained attribute-based access control through smart contracts to prevent unauthorized users from accessing data resource. Thirdly, the linear integer secret sharing algorithm is used to achieve symmetric key sharing among multiple attributes to ensure the security of the key. Finally, the security analysis of the proposed scheme and the performance evaluation using the Hyperledger Caliper tool show the feasibility and effectiveness of the new scheme.

Visual improvement and regeneration of retinal layers in eyes with small, medium, and large idiopathic full-thickness macular holes treated with the inverted internal limiting membrane flap technique over a period of 12 months

PurposeThis study aims to compare the improvement of best-corrected visual acuity (BCVA) and the reduction in defect length of external limiting membrane (ELM) and ellipsoid zone (EZ) in small (< 250 μm), medium (ge 250 μm), and large (ge 400 μm) full-thickness macular holes (FTMH) treated with inverted internal limiting membrane (I-ILM) flap technique over a follow-up period of 12 months.MethodsNinety-one eyes of 87 patients were enrolled in this retrospective study. BCVA and spectral-domain optical coherence tomography (SD-OCT) were conducted preoperatively as well as after 1, 3, 6, 9, and 12 months postoperatively. The defect length of the ELM and the EZ was measured using the caliper tool at each follow-up time point.ResultsBCVA improved significantly in the group of small, medium, and large FTMH over the time of 12 months, whereby the improvement did not depend on FTMH size over 9 months. Only after 12 months, large FTMH showed significantly higher BCVA improvement compared to small and medium FTMH. The closure rate was 100% (91/91). The defect length of ELM and EZ reduced continuously over the period of 12 months. There was a significant correlation between defect length of ELM and EZ with postoperative BCVA.ConclusionThe I-ILM flap technique has very good morphological and functional outcomes in small, medium, and large FTMH over a long-time period, indicating that it can be considered as a treatment option in small and medium FTMH. The defect length of ELM and EZ is directly connected to postoperative BCVA.

A Blockchain‐based Framework for Privacy Preservation of Electronic Health Records (EHRs)

AbstractHealthcare Records are becoming more valuable than ever due to the emergence of various new diseases and the current pandemic. These records are scattered throughout multiple healthcare providers in several places. Keeping them in physical form is time‐consuming; thus, they need to be kept in electronic form. Electronic Healthcare Records (EHRs) are mostly managed at the individual company level, creating a single point of failure and exposing users to various security risks, including amateur‐level attacks and data breaches by hackers. This article proposes a permissioned blockchain‐based framework to overcome the above issues for secured storage and sharing of EHRs over the network. For the overall implementation of the framework Hyperledger Fabric (HLF), InterPlanetary Distributed File System (IPFS), and Identity Based Proxy Re‐Encryption (IB‐PRE) algorithm are used. To create proposed blockchain network, HLF is used. To manage EHRs on the blockchain, IPFS is used where the actual encrypted massive data is stored off‐chain, and their corresponding hash values are stored on the blockchain. Further, IB‐PRE algorithm is used to share EHRs in a safe manner, where a proxy node retrieves requested data from IPFS, performs re‐encryption, and returns the re‐encrypted data to the requester thus, ensures user privacy and data integrity. Finally, the Hyperledger Caliper tool is used to run a performance test to check the system efficiency in terms of throughput and latency. Features and performance‐based comparisons of the proposed and existing related work are made to demonstrate the effectiveness.

Through-Tubing Casing Deformation and Tubing Eccentricity Image Tool for Well-Integrity Monitoring and Plug Abandonment

Casing deformation and tubing eccentricity is a concern in the oil and gas industry for safety and operational reasons. Casing deformation or tubing eccentricity originates from various sources such as well completion, corrosion, formation swelling, collapse, and salt dome creep. It is important to implement a well-integrity surveillance program covering all casing and tubing strings for the full well life cycle from initial completion to abandonment. However, there has been no effective through-tubing logging method to evaluate the casing string for deformation and eccentricity. This paper describes a new Deformation-and-Eccentricity (DEC) tool that is based on electromagnetic technology and designed to measure casing deformation and tubing eccentricity while logging inside completion tubing. The DEC tool generates a unique compressed-and-focused magnetic field that provides an increased signal-to-noise ratio (SNR). The tool then employs an array of magnetic sensors to measure the magnetic flux density distributions azimuthally around the tool. The tool’s compressed-and-focused magnetic field is designed to (1) saturate the magnetic flux of the tubing, (2) to inject more magnetic flux into the first casing behind the tubing, and (3) to increase the signal measurement sensitivity and SNR. The sensor matrix measures flux density changes that correspond to variations in distance between tubing and casing. The high-resolution azimuthal magnetic sensor matrix delivers high-accuracy measurements that are used to image the flux density changes. A finite-element-based forward modeling and an optimized Gaussian processes regression method have been developed to process the raw logging data. The DEC tool has a built-in orientation measurement capability that is based on gyroscopes and accelerometers that are used to align the deformation and eccentricity images and index curves as well as the tubing thickness image. The tool specifications state accuracies of 1% of the eccentricity ratio and 5% of the deformation ratio in the range of casing OD up to 13.375 in. DEC technology provides an advanced answer product for through-tubing casing deformation and eccentricity measurements in downhole well-integrity and plug-abandonment applications. When combined with other well-integrity measurements such as a multifinger caliper and multipipe thickness log tool, a complete well-integrity evaluation can be achieved throughout the life cycle of a well. For example, significant casing deformation can often indicate possible damaged cement behind the casing. Other applications for the technology include locating tubing clamps for fiber-optic cables and control lines and determining the orientation of multistring tubing completions. Performances of the tool have been validated through research simulations, lab tests, and field trials. This paper includes a field case study of a deviated gas production well with tubing buckling and casing micro dogleg.

FULL-THICKNESS MACULAR HOLE SIZE BY HYPERTRANSMISSION SIGNAL ON SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

To assess the full-thickness macular hole (FTMH) size using the choroidal hypertransmission signal on spectral-domain optical coherence tomography and to compare this method to the standard aperture measurement of the minimum aperture size at the level of the neurosensory retina. Cross-sectional study of retrospective data. Eyes with FTMH imaged on spectral-domain optical coherence tomography were included. Two independent masked graders used the device's built-in caliper tool to measure the FTMH minimum aperture size at the level of the neurosensory retina and the size of the corresponding hypertransmission signal below the level of the retinal pigment epithelium/Bruch membrane complex. To assess the reproducibility of the hypertransmission measurement in tilted scans, two measurements were obtained and compared; the first was traced parallel to the retinal pigment epithelium (parallel hypertransmission), and the second was horizontal to the image frame (horizontal hypertransmission), both using Image J software. A total of 31 eyes were enrolled. The mean FTMH minimum aperture size was smaller compared with both the choroidal parallel hypertransmission and horizontal hypertransmission measurements (mean ± SD: 335.7 ± 139.5 µm, 376.7 ± 150.6 µm, 375.1 ± 150.0 µm, respectively. P < 0.001 for both comparisons). The proposed hypertransmission measurement is a feasible and reproducible alternative to assess FTMH size and could provide the basis for an automated FTMH measurement on cross-sectional spectral-domain optical coherence tomography scans, as presented in this study, or on the spectral-domain optical coherence tomography volumetric data set by using an en face projection.

Determination of Horizontal In-Situ Stress Profiles and Rock Deformation Moduli in Karamay Basin Using a Multiobjective Optimization Technique

Summary We introduce a quick and cost-effective method of estimating horizontal in-situ stress profiles and rock elastic moduli vs. depth from geophysical logs taken in vertical well sections. A multiobjective optimization approach finds the optimum solution for the inversion of in-situ stresses and the rock mechanical parameters from elastic borehole deformations measured by the commonly available four-arm caliper tools. The four-arm caliper log responses also permit quality control (QC) of input and identification and classification of borehole sections that display breakouts and sloughing. The method is applied in the estimation of horizontal in-situ stress profiles and rock deformation moduli vs. depth in Karamay Basin, Northwestern China. The results have demonstrated good agreement with available field in-situ stress measurements, indicating promising broader applications of the method.

Role of anterior segment optical coherence tomography in the evaluation of microbial keratitis

Anterior segment optical coherence tomography (AS-OCT) is a newer technology that provides two-dimensional images of corneal infiltration. This study was undertaken to assess whether AS-OCT can aid objective evaluation and response to treatment in resolving microbial keratitis. This prospective study was performed on 17 patients of who underwent slit lamp and AS-OCT examination at presentation and follow up on days 3, 7, 14, 28 and 6 weeks. A standardized scanning protocol was used to measure the corneal thickness (CT) and infiltrate thickness (IT) using the caliper tool of a commercially available AS-OCT device. The mean CT in the infiltrated area and mean IT, both were thickest at presentation (710.88 um and 288.76 um respectively). The mean CT decreased to 665.12 µm, 650.24 µm, 584.35 µm, 549 µm, 507.47 µm on days 3, 7, 14, 28 and 6 weeks respectively. Similarly, the mean IT decreased to 287.24 µm, 244.41 µm, 197 µm, 174.59 µm and 154.82 µm. Paired t- test was used to calculate the statistical change in CT and IT, which was significant (p&amp;#60;0.0001) at 6 weeks, at the rate of 0.67% and 1.01% per day. AS-OCT can show morphological characteristics of microbial keratitis and give quantitative assessment at every follow up.

Microscope-Integrated Intraoperative Optical Coherence Tomography-Guided Big-Bubble Deep Anterior Lamellar Keratoplasty.

The purpose of this study was to evaluate the feasibility of microscope-integrated intraoperative optical coherence tomography (OCT) for real-time quantitative analysis of surgical planes in big-bubble deep anterior lamellar keratoplasty (DALK). In this interventional case series, intraoperative OCT-guided big-bubble DALK was performed in 16 consecutive eyes of 16 patients with keratoconus. Trephination depth was measured using the intraoperative OCT caliper tool. Aiming for a depth within 150 μm from the endothelial surface, the trephination groove was extended to a deeper plane using a 15-degree blade. Repeat OCT scans were taken to measure residual stromal thickness before insertion of the DALK probe from the bottom of the extended trephination. Caliper measurements, success rate of pneumatic dissection, and complications were recorded. After trephination, residual stromal thickness exceeded 150 μm in all eyes and averaged 257.1 ± 42.5 μm. In each case, the initial trephination groove was extended to a depth within 150 μm from the endothelial surface (118.9 ± 27.1 μm). Big-bubble formation was achieved in 12 eyes (75%). Type 1 bubble was obtained in 11 eyes. Perforation requiring conversion to penetrating keratoplasty occurred in 4 eyes during insertion of the cannula into a residual stromal bed of <100 μm (n = 2; 63 and 75 μm) or layer-by-layer dissection (n = 2). Quantitative analysis of intraoperative OCT scans can be used to assist decision-making on whether to proceed with pneumatic dissection or extend the trephination groove, thereby facilitating insertion of the injection cannula at the desired stromal depth.

Agreement of optical coherence tomography thickness measurements between Heidelberg Eye Explorer and ImageJ software

ObjectiveTo investigate the agreement and correlation of manual central foveal thickness (CFT) measurements using the Heidelberg Eye Explorer and ImageJ software. MethodsOptical coherence tomography (OCT) images were identified. CFT was measured using the Heidelberg Eye Explorer caliper tool. Two independent graders measured the CFT of the same images using ImageJ software. A Pearson correlation coefficient, intraclass correlation coefficient, Bland–Altman plots, and coefficient of repeatability were used to assess the agreement and correlation between the Heidelberg Eye Explorer and ImageJ measurements. ResultsOne-hundred and twenty-two OCT images from 91 patients were analyzed. Mean CFT as measured using the Heidelberg caliper tool was 264.8 ± 113 µm. Using ImageJ software, graders 1 and 2 obtained mean CFT values of 267 ± 114.3 µm and 270 ± 114.8 µm, respectively. Pearson correlation revealed a strong correlation between the Heidelberg and Image J measurements (r = 0.999, p < 0.0001). Bland–Altman plots noted a less than 4 µm mean difference between Heidelberg and ImageJ CFT values (2.67 ± 3.46 and 3.72 ± 2.78 µm for graders 1 and 2, respectively). ConclusionThere was strong agreement between the Heidelberg Eye Explorer and ImageJ software for manual CFT measurements. ImageJ may be a reliable tool for thickness measurements when proprietary OCT software is unavailable.

Validation of a Novel Ultrasound Simulation Model for Teaching Foundation-Level Ultrasonography Skills to Veterinary Students.

Veterinary ultrasonography is a complex, advanced skill requiring repetitive exposure and supervision to gain competence. Consequently, newly graduated veterinarians are underprepared and lack the resources to achieve basic ultrasound proficiency upon graduation. Ultrasound simulation has been proposed as an adjunct educational tool for teaching entry-level ultrasound skills to student veterinarians. The objectives of this multicentric prospective observational cohort study were to describe the development of a novel ultrasound training model, establish model construct and face validity, and seek participant feedback. The model was constructed using three-dimensional silicone shapes embedded in ballistics gel within a glass container. A novice cohort of 15 veterinary students and 14 expert participants were prospectively enrolled in the study. Each cohort underwent training and assessment phases using a simulation model. Participants were asked to (a) determine shape location, (b) identify shape type using a shape bank, and (c) measure shape axes using the caliper tool. Time for each phase was recorded. Anonymous post-participation survey feedback was obtained. For most shapes (4/6), experts performed significantly better than novices in identifying shape type and location. Generally, no significant difference was found in mean axis shape measurements between cohorts or compared to the true mean axis measurements. No significant difference was found in scan time for either phase. This study's results support the validation of this ultrasound simulation model and may demonstrate early evidence for its use as a training tool in the veterinary curriculum to teach entry-level ultrasound skills.

Vision Based Self Adaptive Algorithm for 6 Axis ABB Industrial Welding Robot

The ultimate aim of this work “Vision Based Self Adaptive Algorithm for 6 Axis ABB Industrial Welding Robot” is to develop a self-adaptive RAPID algorithm based on the captured image of the work piece. The image of the work piece is captured using NI Guppy pro F031C camera which has 300 DPI with 120 FPS resolution. The captured image is transferred to the LabVIEW software for developing the self-adaptive algorithm through RS232 serial communication protocol. The LabVIEW vision assistant module is used to develop an algorithm based on the geometry of the captured image. The various image processing operations like Thresholding, Morphological operation (Thinning), and edge detection are carried out. The caliper tool is used to measure the distance between the coordinate points (welding distance). With the aid of Visual Basic, the measured values are converted into coordinates. The coordinates are used to develop a RAPID program with the aid of ABB Robot Studio library functions. The virtual server is established between the ABB Robot Studio and IRC5 Controller with the use of MOD-BUS protocol with VISA. After receiving the data from the MOD-BUS, the IRC5 controller moves the ABB Industrial Robot End effectors along with the welding gun for the welding purpose. The work piece is located on the designed jigs and fixtures. The different types of welding with different design can be incorporated with the Vision Assistant module for further development. To illustrate the developed algorithm, robot assisted MIG welding process is carried out. The welded work-pieces are tested for its strength quality and the results are verified. Optimal welding parameters for the good quality of weldment identified by using Taguchi method of optimization.