A Randomized Controlled Trial Comparing the Effect of Two-Time Durations of Balloon Compression During Percutaneous Balloon Compression in Resistant Trigeminal Neuralgia.

BACKGROUND: Percutaneous balloon compression of the trigeminal nerve's gasserian ganglion for the treatment of trigeminal neuralgia is an interventional pain procedure with results comparable to microvascular decompression surgery. The procedure is safe in experienced hands and has less morbidity associated with it. However, there is a lack of clear-cut guidelines about the details of the technique like balloon shape, inflation pressure, and duration of inflation. So, keeping the inflation pressure and shape of the balloon constant, we studied the effect of the duration of inflation of the balloon and its effect on pain relief in refractory trigeminal neuralgia cases. OBJECTIVES: To study the outcome with 2 different durations of balloon inflation times in terms of pain relief and complications after percutaneous balloon compression. STUDY DESIGN: Prospective parallel design randomized, controlled trial. SETTING: The study was conducted in a tertiary care hospital in North Eastern India after obtaining approval from the Institutes' ethics committee (Dean/2018/EC/449). The study was also registered with the Clinical Trials Registry of India (CTRI no. CTRI/2019/03/018166). All patients referred to a pain clinic for unilateral facial pain were screened for the study over  2 years from April 2019 to March 2021. METHODS: Forty patients who met the diagnosis of trigeminal neuralgia and who did not respond satisfactorily to medications were included in the study. They underwent routine blood investigations and a magnetic resonance image of the brain to rule out any medical or surgical conditions. Percutaneous balloon compression was conducted under C-arm guidance using a 12 gauge cannula and a 4 Fr Fogarty balloon was used for compressing the gasserian rootlets. RESULTS: Patients who underwent 90 seconds as well as 120 seconds showed good pain relief. The 2 groups did not show any significant difference in pain relief based on the duration of compression. Visual analog scale scores were reduced from 7-8 to 0-3. Masseter muscle weakness was present in 47.5% of patients post-procedure and recovered in all except one patient. LIMITATIONS: We have followed up with our patients for a short period of 6 months only. We could not measure the intra-luminal compression pressure of the balloon. CONCLUSION: There is no difference in the pain relief obtained by the 2 different durations of compressions. A longer duration of compression, however, has more incidence of side effects.

Effect of 3% Hypertonic Saline Resuscitation on Lactate Clearance and Its Comparison With 0.9% Normal Saline in Traumatic Injury Patients: A Prospective Randomized Control Trial.

BACKGROUND:  Fluid resuscitation with normal saline (NS) can aggravate lactate production. The objective of this study was to evaluate the efficacy of small-volume resuscitation using 3% hypertonic sodium chloride (HS) and its comparison with NS in trauma patients. The primary endpoint was an increase in lactate clearance after 1 hr of fluid resuscitation. The secondary endpoint was the incidence of hemodynamic stability, the volume of transfusion, correction of metabolic acidosis, and complications such as fluid overload and abnormal serum sodium levels. MATERIALS AND METHODS: It was a prospective, randomized, single-blind study. The study was conducted on 60 patients who arrived at the trauma center for emergency operative intervention. Inclusion criteria for patient selection were trauma victims of age more than 18 years and the requirement of emergency operative intervention for trauma except for traumatic brain injury. Patients were divided into two groups: Group HS (hypertonic saline) and Group NS (normal saline). Patients were resuscitated with either 3% HS (4ml/kg) or 0.9% NS (20ml/kg). RESULTS: The HS group had higher lactate clearance at 1 hour compared to the NS group, and this difference was statistically significant with a p-value of <0.001. When hemodynamic parameters were compared at 30 and 60 minutes after resuscitation, the HS group had a significantly lower heart rate (p<0.05 at 30 minutes and <0.001 at 60 minutes, respectively), a higher mean arterial pressure at 60 minutes (p<0.001), a higher pH at 60 minutes (p< 0.05), and a higher bicarbonate concentration at 60 minutes (p<0.05). The HS and NS groups had significant differences in serum sodium levels at 60 minutes (p<0.001). CONCLUSIONS: Resuscitation with 3% hypertonic saline improved lactate clearance. Lower volumes of fluid infusion for resuscitation achieved better hemodynamic stability and correction of metabolic acidosis in the hypertonic saline group. Our study shows that hypertonic saline can be a promising fluid for small-volume resuscitation in trauma patients with compensated mild to moderate shock.

Securing Optical Networks Using Quantum-Secured Blockchain: An Overview.

The deployment of optical network infrastructure and development of new network services are growing rapidly for beyond 5/6G networks. However, optical networks are vulnerable to several types of security threats, such as single-point failure, wormhole attacks, and Sybil attacks. Since the uptake of e-commerce and e-services has seen an unprecedented surge in recent years, especially during the COVID-19 pandemic, the security of these transactions is essential. Blockchain is one of the most promising solutions because of its decentralized and distributed ledger technology, and has been employed to protect these transactions against such attacks. However, the security of blockchain relies on the computational complexity of certain mathematical functions, and because of the evolution of quantum computers, its security may be breached in real-time in the near future. Therefore, researchers are focusing on combining quantum key distribution (QKD) with blockchain to enhance blockchain network security. This new technology is known as quantum-secured blockchain. This article describes different attacks in optical networks and provides a solution to protect networks against security attacks by employing quantum-secured blockchain in optical networks. It provides a brief overview of blockchain technology with its security loopholes, and focuses on QKD, which makes blockchain technology more robust against quantum attacks. Next, the article provides a broad view of quantum-secured blockchain technology. It presents the network architecture for the future research and development of secure and trusted optical networks using quantum-secured blockchain. The article also highlights some research challenges and opportunities.

MSE-based analysis of circular grating self-images for testing beam collimation.

Mean square error (MSE) is used to detect variations in the period between a pair of self-images formed at two different Talbot planes of a circular grating (CG) using a beam splitter in a conventional collimation testing setup. By varying the position of the collimator with respect to the point source, the collimation state of the input beam is varied and the computed MSEs are analyzed to deduce the collimation state. The minimum value of the MSE indicates beam collimation. For equal sized images, the MSE relates to the sum of the squared difference between spatially correspondent pixel values of the images. Since comparison of the spatial information takes place at the pixels' level, any small spatial shift between patterns of the two self-images due to collimation error is detected with precision. The CG, comprising concentric circular structures, offers added advantage in terms of error-free alignment, which otherwise is error prone and cumbersome with widely used linear gratings. It is well known that self-images formed with circular grating have good fidelity with less optical distortions and irregularities, especially at distant Talbot planes. Also, the self-images formed with circular gratings are less affected by lens aberrations, tilts, misalignments, etc. Higher sensitivity in beam collimation is achievable, as self-images of a CG can be recorded at widely separated Talbot planes, and analyzed using an algorithm which is more responsive toward any minute difference between them. The suggested method is promising for a quick collimation setting with good accuracy and enhanced sensitivity.

Comparative analysis of image pre-filtering techniques for phase-shifted noise-affected interferograms.

Phase-shifting techniques are one of the most promising strategies to extract the phase information and retrieve the parameters of interest (e.g., refractive index, beam collimation, object shape, deformations, thickness, focal length, etc.) from interferograms. However, traditional phase-shifting techniques suffer from both internal and external noise, which reduce measurement accuracy. This paper reports a comparative analysis of the three commonly used filtering techniques, namely, Fourier, windowed Fourier, and wavelet filtering for noise reduction and accurate extraction of phase information from phase-shifted interferograms. Toward this, two basic types of noise (additive and multiplicative noise) are introduced in the simulated interferograms and processed using the pre-filtering strategies. The effect of second-order harmonics in the presence of noise is also examined. In addition, experimental demonstrations of the real-life applicability of the analyses are provided using the interferograms recorded on coherent (Talbot) and incoherent (Lau) grating shearing interferometers. High accuracy in the measurement of defocusing error of the lens is obtained using the filtering strategies. Further inferences and insights are drawn in favor of the pre-filtering techniques.

Anti-Voltage-Gated Potassium Channel Antibody Syndrome: A Rare Cause of Hyponatremia in Intensive Care Unit.

Hyponatremia causing seizure is a common cause for admission in the critical care unit. Here, we describe a peculiar case of seizure due to hyponatremia, associated with anti-voltage-gated potassium channel antibody syndrome. This case emphasizes that how a proper workup can unveil unusual but potentially treatable causes of hyponatremia. The hallmark of this syndrome is that neurological symptoms may relapse or progress if the disorder is not recognized in time. This case report emphasizes the point that how a keen observation may decode subtle signs of the grave but potentially treatable pathologies.

Life cycle analysis of electrically actuated SMA spring using Talbot interferometry.

Electrically actuated shape memory alloys (SMAs) find widespread applications in engineering and science. Such materials are known to retain/remember their state. In the stressed/deformed state, when activated by the application of a suitable excitation mechanism, such as the use of heat or potential, they return to their original unstressed state. To test their reliability, it is a standard procedure to undertake a life cycle analysis. In this paper, the life cycle analysis of a SMA spring using the Talbot interferometric technique is reported. The life cycle of the SMA spring is analyzed in terms of the displacement drift, which sets in because of the functional fatigue generated due to its repeated use. Collimated light from a He-Ne laser transmitted through a beam splitter is converged through a focusing lens onto a plane mirror attached to the spring. Backreflected light from the mirror is incident on a set of two Ronchi gratings separated by the Talbot distance, forming a moiré pattern. The resulting interferograms are analyzed using a fringe rotation mechanism. The angle of orientation is a function of displacement drift. There is deterioration in the SMA property because of repeated cycles, and the spring loses its ability to return to its original unstretched position. The values of the displacement drift generated after 1, 1000, 2000, 3000, 4000, and 5000 such cycles as measured using a Talbot interferometer are 0, 0.875, 1.275, 1.459, 1.720, and 1.859 mm, respectively. It is observed that the SMA effect deteriorates as the number of stretching/contraction cycles increases. The uncertainty analysis is also reported. The expanded uncertainty was determined to be 201.61 µm.

Automated collimation testing by determining the statistical correlation coefficient of Talbot self-images.

In this paper, we propose a simple, fast, and accurate technique for detection of collimation position of an optical beam using the self-imaging phenomenon and correlation analysis. Herrera-Fernandez et al. [J. Opt.18, 075608 (2016)JOOPDB0150-536X10.1088/2040-8978/18/7/075608] proposed an experimental arrangement for collimation testing by comparing the period of two different self-images produced by a single diffraction grating. Following their approach, we propose a testing procedure based on correlation coefficient (CC) for efficient detection of variation in the size and fringe width of the Talbot self-images and thereby the collimation position. When the beam is collimated, the physical properties of the self-images of the grating, such as its size and fringe width, do not vary from one Talbot plane to the other and are identical; the CC is maximum in such a situation. For the de-collimated position, the size and fringe width of the self-images vary, and correspondingly the CC decreases. Hence, the magnitude of CC is a measure of degree of collimation. Using the method, we could set the collimation position to a resolution of 1 µm, which relates to ±0.25 µ radians in terms of collimation angle (for testing a collimating lens of diameter 46 mm and focal length 300 mm). In contrast to most collimation techniques reported to date, the proposed technique does not require a translation/rotation of the grating, use of complicated phase evaluation algorithms, or an intricate method for determination of period of the grating or its self-images. The technique is fully automated and provides high resolution and precision.

Collimation testing using deflectometry in conjunction with windowed Fourier transform analysis.

In this paper, we demonstrate a simple automated procedure for the detection of collimation of an optical beam by incorporating the windowed Fourier fringe analysis technique into a deflectometric setup. The experimental arrangement consists of a deflectometry-based system in which light from a laser is expanded and passed through a collimating lens. The transmitted light illuminates a coarse sinusoidal grating. The grating image is directly captured through a charge-coupled device. Typical image patterns corresponding to "in-focus," "at-focus," and "out-of-focus" positions of an optical beam are recorded. Depending on the position of the collimating lens, the grating line spacing and the resulting phase of the emerging wavefront varies. Direct phase measurement using the windowed Fourier transform method has been used to obtain the slope map of the wavefront. The slope of the phase map depicts the diverging, collimated, or converging nature of the optical beam. The positioning error of light beam collimation was approximately 1 µm. The experimental arrangement is simple, low cost, and compact. The technique is fully automatic and provides high resolution, high precision, and good sensitivity.

Fingerprint detection and mapping using a phase shifted coherent gradient sensing technique.

In this paper, a full field technique for mapping a latent fingerprint using a coherent gradient sensing (CGS) sensor is proposed. Collimated light from an He-Ne laser illuminates a specimen comprising a fingerprint implanted onto a reflecting surface. Reflected light from the specimen is analyzed using the CGS sensor comprising a pair of gratings. Reflected light carries information regarding the depth and orientation of furrows and ridges in the fingerprint. The topological information of the fingerprint is retrieved using four-step phase shifting interferometry. Well-defined 2D and 3D phase plots have been reconstructed to map the topography of the human fingerprint. The recorded slope data reconstructs the information regarding the separation and depth of the ridges in the latent fingerprint. The proposed technique is noninvasive and full field and does not require any kind of chemical or physical treatment. The sensor is very simple, yields interferometric sensitivity, and has the advantages of easy alignment, compactness, and low cost.

Intraoperative tumor lysis syndrome in a child with Wilms' tumor.

Tumor lysis syndrome in an onco-metabolic emergency resulting from massive lysis of rapidly proliferating malignant cells seen commonly in patients with hematological malignancies such as acute lymphocytic leukemia and Burkitt's lymphoma and is quite rare in solid tumors. Spontaneous development of tumor lysis has been described among other trigger factors such as corticosteroid therapy, anesthesia, tumor manipulation during surgery and pyrexia. We describe such a case in a 5-year-old boy posted for excision and staging of a massive Wilms' tumor who developed a hyperkalemic cardiac arrest during the procedure and its subsequent intraoperative and postoperative management. Intraoperative cardiac arrest is a stressful situation for both the anesthesiologist and the surgeon, more so when it involves a child. The aim of this report is to make the anesthesiologist aware of the possibility and occurrence of such a phenomenon in children and be adequately prepared for such an emergency.

Phase-shifting lateral shearing interferometry using wedge-plate and interferometric grating.

A simple and robust method for introducing a phase-shifting test procedure in a wedge-plate shearing interferometer is proposed. The output of the wedge-plate lateral shearing interferometer (LSI) is superposed onto a sinusoidal grating, forming a moiré pattern. The in-plane translation of grating perpendicular to the grating lines is used for introducing a known amount of phase shifts in the interferometer. Direct measurement of phase using a four-step phase-shifting method is undertaken. The applicability of this devised phase-shifting wedge-plate LSI has been successfully tested for setting the collimation position of optical beams. Good accuracy and precision are achieved.

Cardiac tamponade by hydatid pericardial cyst: a rare case report.

INTRODUCTION: Hydatid cysts are most commonly found in the liver and lungs but they are rarely found in pericardium. CASE PRESENTATION: We present a rare case of isolated hydatid cyst in pericardium of heart of a 70 year old female presented in casualty with unusual features like, dyspnea, palpitation and chest pain mimicking acute coronary syndrome. DISCUSSION: Hydatid cyst in Pericardium represents only 0.5-2% of cases of systemic echinoccocal infection. Isolated pericardial cyst is very rare in endemic region and may present mimicking acute coronary syndrome. Cardiac hydatid cysts should always be considered in presence of eosinophilia as present like acute coronary syndrome in endemic area.

Comparison of Ranson, Glasgow, MOSS, SIRS, BISAP, APACHE-II, CTSI Scores, IL-6, CRP, and Procalcitonin in Predicting Severity, Organ Failure, Pancreatic Necrosis, and Mortality in Acute Pancreatitis.

Background. Multifactorial scorings, radiological scores, and biochemical markers may help in early prediction of severity, pancreatic necrosis, and mortality in patients with acute pancreatitis (AP). Methods. BISAP, APACHE-II, MOSS, and SIRS scores were calculated using data within 24 hrs of admission, whereas Ranson and Glasgow scores after 48 hrs of admission; CTSI was calculated on day 4 whereas IL-6 and CRP values at end of study. Predictive accuracy of scoring systems, sensitivity, specificity, and positive and negative predictive values of various markers in prediction of severe acute pancreatitis, organ failure, pancreatic necrosis, admission to intensive care units and mortality were calculated. Results. Of 72 patients, 31 patients had organ failure and local complication classified as severe acute pancreatitis, 17 had pancreatic necrosis, and 9 died (12.5%). Area under curves for Ranson, Glasgow, MOSS, SIRS, APACHE-II, BISAP, CTSI, IL-6, and CRP in predicting SAP were 0.85, 0.75, 0.73, 0.73, 0.88, 0.80, 0.90, and 0.91, respectively, for pancreatic necrosis 0.70, 0.64, 0.61, 0.61, 0.68, 0.61, 0.75, 0.86, and 0.90, respectively, and for mortality 0.84, 0.83, 0.77, 0.76, 0.86, 0.83, 0.57, 0.80, and 0.75, respectively. Conclusion. CRP and IL-6 have shown a promising result in early detection of severity and pancreatic necrosis whereas APACHE-II and Ranson score in predicting AP related mortality in this study.

Penetrating injury of ascending aorta with arrow in situ.

Penetrating injuries of the aorta are rare and highly lethal; very few patients are able to reach the hospital alive. We report a case of penetrating injury into the ascending aorta with the arrow still in situ, shot by a bow in a tribal region of India. The wound of entry into the aorta was sealed by the arrow itself. The patient came to us walking and supporting the arrow with his left hand. He was operated on, and the arrow was successfully removed from the aorta.

Slope measurement of bent plates using double grating shearing interferometry.

A grating-based shearing interferometeric setup for slope measurement of bent plates has been proposed. The specimen under test is illuminated by a collimated beam from the laser. Light reflected from the specimen passes through two identical holographic gratings placed in tandem. The grating frequency has been so chosen that the diffracted orders from each grating are separated out distinctly. Two first-order beams diffracted from each of the gratings superpose in space. In the resulting interferogram, the fringes due to slope information of the object are visualized. Mathematical formulation for experimental determination of slope values has been undertaken. Validation of the experimental results with theoretical predictions in case of cantilever beam provides good correlation. The main advantage of the technique has been the realization of very compact geometry without the need for spatial filtering arrangement commonly associated with the grating-based techniques used to date.

Automated collimation testing by incorporating the Fourier transform method in Talbot interferometry.

In this paper, we report an automated technique for collimation testing by incorporating Fourier fringe analysis of the recorded interferograms in Talbot interferometry. The triangular profile of Talbot interferometric fringes has been recorded using a CCD and computer system. The interferograms corresponding to the in-focus, at-focus, and out-of-focus positions of the collimating lens have been recorded. Direct phase measurement using the Fourier transform method has been used for detection of collimation positions. Good accuracy and precision in measurement have been achieved.

Therapeutic drug monitoring by reverse iontophoresis.

Therapeutic molecules possessing distinct pharmacokinetic variation, narrow therapeutic index and concentration dependent therapeutic/adverse effects demand constant monitoring. The current methods for blood sampling are invasive and possess low patient compliance. Human skin, selective and effective membrane to chemical permeation, offers an alternative route for the extraction of endogenous molecules in the body. Significant attention has been received in the application of reverse iontophoresis in extracting drugs/biomaterials from the subdermal region. This technique involves transiting of a low electric current across the skin usually with couple of skin electrodes to extract charged as well as neutral molecules. Electromigration and electroosmosis are the two basic mechanisms involved in transport of molecules. Several in vitro and in vivo experiments demonstrated the potential of reverse iontophoresis as a noninvasive tool in clinical chemistry and therapeutic drug monitoring. This technology is currently being used in device such as Glucowatch Biogrpaher which allows blood glucose detection across skin layers. Advances in technology and rapid progress in research has widely improved the opportunity of this system, and the recent trend indicates that several products are likely to be developed very soon. This review provides an overview about the recent developments in reverse iontophoresis for therapeutic drug monitoring.

A comparative study of surgical treatment of small aortic root with or without aortic root enlargement using a single prosthesis type.

BACKGROUND: The ideal management of aortic stenosis in patients with a small aortic root remains controversial. Reports of adverse effects of patient-prosthesis mismatch (PPM) from a small-sized valve have to be weighed against the increased morbidity and mortality of aortic root enlargement procedures. METHODS: The present study retrospectively reviewed and compared clinical data of patients with predominant aortic stenosis with small aortic root (n = 209) who underwent isolated aortic valve replacement without (AVR group, n = 162) or with aortic root enlargement (AVR + ARE group, n = 47) using a single prosthesis type between January 2002 and June 2008 to assess their effect on perioperative outcomes. RESULTS: The in-hospital mortality (4.28% in AVR + ARE vs. 3.08% in AVR group) and other perioperative outcomes were similar in both the groups. Although patients of the AVR + ARE group had a greater degree of left-ventricular (LV) mass regression (-41.3 ± 32.1 vs. -21.5 ± 37.4) in the follow-up period at 12 months, there was no significant difference in functional outcome. Patients with severe postoperative PPM (indexed effective orifice area ≤0.65 cm²/m² body surface area) showed increased perioperative mortality (9.52 vs. 1.85%) and less regression of LV mass (-13.2.8 ± 27.1 vs. -27.6 ± 31.9), higher transvalvular gradient and were more symptomatic at 12-month follow-up (New York Heart Association class 1.44 ± 0.41 vs. 1.22 ± 0.28) compared to those who were having only mild to moderate PPM (indexed effective orifice area > 0.65). CONCLUSION: ARE procedures are invaluable techniques in surgical management of small aortic root patients and can be used without significantly increasing early morbidity and mortality, particularly in those cases in which AVR with a small prosthesis will lead to severe PPM.

Real-time slope mapping and defect detection in bent plates using Talbot interferometry.

We demonstrate a simple method for obtaining slope contours of bent plates using Talbot interferometry. The technique has been used to map slope contours of polymethyl methacrylate specimens of different shapes. The Talbot image of a coarse grating is projected onto a specimen such that the self-image is backreflected onto the same grating again. As a Talbot interferometer is basically a grating shearing interferometer, it results in the generation of characteristic slope maps of the specimen under test. Results of the investigation match well with other slope-mapping techniques. Validation of experimental results with theoretical predictions in the case of a cantilever beam specimen has been undertaken. Accuracy of about 4.7% with respect to theoretical predictions is obtained.