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Sural nerve is the most common nerve used as a source for nerve grafting. Open harvest with longitudinal incisions produces unsightly scars, and this have led to development of less invasive techniques using endoscopes, nerve stripper, and mini-incisions. Several anatomical classifications have also been proposed due to the variations in the anatomy of the sural nerve. A simple and practical surgicoanatomical classification of the sural nerve based on which we have refined our minimal access technique, the multiple mini-incision technique for sural nerve harvest is proposed. In this technique, the incisions required for harvest of the sural nerve are standardized and predictable. A fibular incision is required when the sural nerve has major contribution from the common peroneal nerve. We have found this a simpler and reliable technique of harvest of sural nerve in nerve reconstructive surgery.

Digital fringe multiplication is a useful technique for obtaining fractional fringe orders in photoelasticity at regions with very feeble retardations. In this paper, the effectiveness of the existing fringe multiplication techniques is investigated theoretically and experimentally. A new approach for fringe multiplication, using background nullified fringes, is developed to overcome the prevailing issues. Three options for obtaining background nullified fringe patterns are explained. Further, quadrature transformation of these fringe patterns is carried out to fetch uniform modulation. Moreover, a simplified fringe multiplication method is worked out to obtain fractional fringes from the uniformly modulated fringe patterns. The proposed procedures have been demonstrated through simulated as well as experimental images. A parametric study is carried out to understand the influence of pixel resolution and bit depth of the images on fringe multiplication. A criterion is established for finding out the maximum possible fringe multiplication for a given initial pixel/fringe resolution. It is observed that, for higher levels of fringe multiplication, larger bit depth of the image in conjunction with sufficient fringe resolution would be essential. The same also holds for fringe multiplication at areas with stress concentrations.

Ramberg-Osgood (R-O) type stress-strain models are commonly employed during elasto-plastic analysis of metals. Recently, 2-stage and 3-stage R-O variant models have been proposed to replicate stress-strain behavior under large plastic deformation. The complexity of these models increases with the addition of each stage. Moreover, these models have considered deformation till necking only. In this paper, a simplistic multi-stage constitutive model is proposed to capture the strain-hardening non-linearity shown by metals including its post necking behavior. The constitutive parameters of the proposed stress-strain model can be determined using only elastic modulus and yield strength. 3-D digital image correlation was used as an experimental tool for measuring full-field strains on the specimens, which were subsequently utilized to obtain the material parameters. Our constitutive model is demonstrated with an aerospace-grade stainless steel AISI 321 wherein deformation response averaged over the gauge length (GL) and at a local necking zone are compared. The resulting averaged and local material parameters obtained from the proposed model provide interesting insights into the pre and post necking deformation behavior. Our constitutive model would be useful for characterizing highly ductile metals which may or may not depict non-linear strain hardening behavior including their post necking deformations.

Cerebrovascular reactivity mapping performed with resting-state blood oxygen level–dependent functional MRI provided a task-free method for measuring cerebrovascular reserve in both healthy adults and patients with Moyamoya disease and is sensitive to revascularization surgery.

Time average digital holography under random excitation or square wave excitation is established as an on-site non-destructive testing tool for defect detection in large metallic and composite sandwich structures due to its high sensitivity, single exposure interferogram, and fast inspection capability. However, extensive calibration studies are necessary to corroborate the defect type and defect size with the excitation frequency range and excitation magnitude. In this paper, a method to simulate a time average digital holographic fringe pattern under random excitation is proposed with the idea to minimize the number of calibration experiments and also for better evaluation of the size and type of defect. The proposed method circumvents the requirement for a closed form expression for the complex characteristic fringe function for time average interferometry under random excitation. The computed fringe pattern is illustratively compared with an experimental time average digital holographic fringe pattern.

BackgroundTeleconsultation over the smartphone is now widely used in modern medicine in the management of burns, flap cover, upper extremity trauma, and in the assessment of the feasibility of reimplantation in amputated fingers. The development of the WhatsApp application has enhanced the smartphone's efficiency remarkably to transmit images in clinical and academic settings with its failsafe and encrypted technology. In hand surgery, a teleconsultation technology must communicate details of finger vascularity effectively. However, there is a paucity of evidence on the functionality of these modern teleconsultation technologies in Hand Surgery. Here, the authors have estimated the efficiency of the WhatsApp teleconsultation in the assessment of finger vascularity.

The inspection of face sheet bonding, through optical interferometry techniques like holography and shearography, in potted-insert honeycomb-cored sandwich panels is different from the inspection of panels without inserts due to their complex response toward thermal and vibration stressing. In this paper, the dynamic responses of metallic honeycomb-cored sandwich structures with bonded and debonded inserts are studied using time-averaged digital holography and illustrated. At high frequencies, the face sheet regions at perfectly bonded inserts act as hard points, and regions across a debonded insert locally resonate in the sensitivity range of interferometry. Since the discontinuities created by such inserts are very complex to simulate numerically, we simulate potted-insert sandwich structures through plates with multiple holes and with multiple fully and partially bonded local stiffeners to validate this fast inspection procedure. The simulated dynamic response of the plates is compared with the time-averaged digital holography results. The operational deflection shapes near stiffeners are similar to those of fully potted inserts in a sandwich panel. Thus, the extent of debond can be evaluated at high frequencies as simulated through partially bonded stiffeners.

Sandwich structures, in the modern aerospace industry, are more sought after due to their high strength to stiffness ratio resulting in significant weight gains. Optical techniques like time-average holography and shearography are preferred in industries for inspection of huge sandwich and composite panels because of whole-field (full coverage) inspection in a lesser time leading to large savings in cost. These techniques conventionally use sinusoidal frequency sweep to capture the local resonance of defective regions. This paper highlights the difficulties with the conventional approach of time-average digital holography (TADH) and proposes a novel defect identification strategy through square wave excitation. The proposed method enhances the speed and accuracy of inspection; thereby it saves cost and increases confidence level. Extensive experiments have been carried out using honeycomb sandwich panels to demonstrate the methodology.

This paper demonstrates a unique application of DIC wherein the structural performance and structural integrity have been evaluated together almost in real-time. The results obtained from the ground level tests, simulating the bonding between the TPS to the base structure of a space crew module, are reported to find the adequacy of two different adhesives prior to actual bonding. The test objective was to characterize the adhesives based on the structural performance (deflection and strain behavior) of the TPS and conduct health monitoring in real-time (i.e. abort the test whenever the TPS fails). The dual objective could be met using DIC in a full-field and non-contact manner, which was essential due to the limitations of the contacting type measurements.

Advanced ceramics are increasingly utilised in various engineering applications such as aerospace, marine, automobile, etc. Grinding is commonly used for producing parts of high precision and high surface quality from advanced ceramics. But, there are only a few investigations on the effects of process parameters on surface roughness of advanced ceramics in surface grinding. The objective of this work is to model and optimise surface roughness of silicon carbide (SiC) advanced ceramic material during surface grinding. In the present work, a new for surface roughness in surface grinding of SiC advanced ceramic material is proposed. Effectiveness of this model is proved by comparison of the experimental results with the predicted results. Finally, optimisation of surface roughness is done considering machining parameters such as table feed rate, depth of cut and wheel speed using response surface methodology (RSM) in Design Expert software.

A new species of PremnaL., Premna rajendranii, is described from the Kerala and Tamil Nadu parts of Western Ghats. Detailed description, colour photographs, phenology, conservation status, distributional details and relevant taxonomic notes are provided along with a key to the Premnaspp. distributed in Kerala.

Intrinsic hand muscles can occasionally be used as pedicled flaps for wound coverage or functioning transfer in hand trauma. The purpose of this study was to define the vascular supply of the individual intrinsic muscles of the hand for potential use of these muscles as muscle flaps.

Musculocutaneous perforator flaps, or more simply, perforator flaps, have become increasingly popular in microsurgery because of numerous advantages, including reduced donor-site morbidity. The thoracodorsal artery perforator flap is a cutaneous flap based on cutaneous perforators of the thoracodorsal vessels. The objective of this study was to document the vascular anatomy of this flap in human cadaveric studies.

The accuracy of a diagnostic test used to classify a patient as having disease or being disease-free is a valuable piece of information to be used by the physician when making treatment decisions. If a standard reference test is available, determining the sensitivity and specificity of a new test is straightforward. However, if that reference test is incorrectly assumed to be perfectly sensitive and specific, the errors of the reference test can result in an underestimation of the accuracy of the test being evaluated. Latent class analysis can be applied to determine the sensitivity and specificity of a new test when no standard exists.

Traumatic musculotendinous junction avulsions are rare injuries except in avulsion amputations. They pose a significant challenge to the treating surgeon. We present a 24-year-old male who sustained an open musculotendinous avulsion of the flexor pollicis longus tendon. He was treated with primary tendon transfer using the flexor digitorum superficialis of ring finger, in flexor zone 3. The functional result at 10 months following surgery was excellent.