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Singh A, Subedi K, Shrestha A, Bhagat T, Pyakurel P, Agrawal SK. Impact of Community Diagnosis Programme on Undergraduate Students at BP Koirala Institute of Health Sciences. Kathmandu Univ Med J (KUMJ) 2019; 17:82-87. [PMID: 32632052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Background Community Diagnosis Programme (CDP) aims to demonstrate the importance of teamwork in health care to understand the comprehensive health needs of the rural people and conceive about the research. Objective To assess the impact of community diagnosis program on undergraduate students of BP Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal. Method A cross sectional study with mixed design (quantitative and qualitative) was conducted among the undergraduate students of batch 2017 participating in community diagnosis programme of BP Koirala Institute of Health Sciences, Dharan, Nepal. Eight questions assessed the students' perceptions regarding their abilities about community diagnosis program using six point Likert Scale and four open ended questions were used to know the students' experience and perception of community diagnosis programme. Result Overall mean ± SD score for pre-exposure response was 30.47 ± 6.18 and for the post-exposure response was 40.49 ± 5.16. The overall mean ± SD score of the students categorized according to streams showed similar results in both pre-exposure response and post-exposure responses. Qualitative analysis revealed the themes like "Research, a reflection of community and new method of learning to medical students"; "method of developing confidence and good communication skills", "learning to work as a team" and "exposure to rural area"; "Research an adjunct to medical profession". Conclusion Community diagnosis programme had a positive impact on the students about basic survey process, learnt to communicate with rural people, understood the type of data and were willing to participate in similar projects in future. Qualitative analysis showed most of the students had positive experience with some negative experience of community diagnosis programme.
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Van Osch K, Allen D, Gare B, Hudson TJ, Ladak H, Agrawal SK. Morphological analysis of sigmoid sinus anatomy: clinical applications to neurotological surgery. J Otolaryngol Head Neck Surg 2019; 48:2. [PMID: 30635049 PMCID: PMC6329078 DOI: 10.1186/s40463-019-0324-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/02/2019] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVES The primary objective of this study was to use high-resolution micro-CT images to create accurate three-dimensional (3D) models of several intratemporal structures, and to compare several surgically important dimensions within the temporal bone. The secondary objective was to create a statistical shape model (SSM) of a dominant and non-dominant sigmoid sinus (SS) to provide a template for automated segmentation algorithms. METHODS A free image processing software, 3D Slicer, was utilized to create three-dimensional reconstructions of the SS, jugular bulb (JB), facial nerve (FN), and external auditory canal (EAC) from micro-CT scans. The models were used to compare several clinically important dimensions between the dominant and non-dominant SS. Anatomic variability of the SS was also analyzed using SSMs generated using the Statismo software framework. RESULTS Three-dimensional models from 38 temporal bones were generated and analyzed. Right dominance was observed in 74% of the paired SSs. All distances were significantly shorter on the dominant side (p < 0.05), including: EAC - SS (dominant: 13.7 ± 3.4 mm; non-dominant: 15.3 ± 2.7 mm), FN - SS (dominant: 7.2 ± 1.8 mm; non-dominant: 8.1 ± 2.3 mm), 2nd genu FN - superior tip of JB (dominant: 8.7 ± 2.2 mm; non-dominant: 11.2 ± 2.6 mm), horizontal distance between the superior tip of JB - descending FN (dominant: 9.5 ± 2.3 mm; non-dominant: 13.2 ± 3.5 mm), and horizontal distance between the FN at the stylomastoid foramen - JB (dominant: 5.4 ± 2.2 mm; non-dominant: 7.7 ± 2.1). Analysis of the SSMs indicated that SS morphology is most variable at its junction with the transverse sinus, and least variable at the JB. CONCLUSIONS This is the first known study to investigate the anatomical variation and relationships of the SS using high resolution scans, 3D models and statistical shape analysis. This analysis seeks to guide neurotological surgical approaches and provide a template for automated segmentation and surgical simulation.
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Koch RW, Saleh H, Folkeard P, Moodie S, Janeteas C, Agrawal SK, Ladak HM, Scollie S. Skill Transference of a Probe-Tube Placement Training Simulator. J Am Acad Audiol 2019. [DOI: 10.3766/jaaa18054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Koch RW, Moodie S, Folkeard P, Scollie S, Janeteas C, Agrawal SK, Ladak HM. Face and Content Validity of a Probe Tube Placement Training Simulator. J Am Acad Audiol 2018; 30:227-234. [PMID: 30461412 DOI: 10.3766/jaaa.17114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Probe tube placement is an important skill audiologists must learn to make real-ear measurements in an audiology clinic. With current evidence-based guidelines recommending insertion of the probe tube within 5 mm of the tympanic membrane (TM) for proper acoustical measurements, students must be well trained to ensure they are capable to perform this placement in clinical practice. This is not always the case as it has been found that real-ear measurements are not performed in a clinic as often as required. To address this, a simulator consisting of a 3D-printed ear model and an optical tracking system was developed to provide a training system for students to practice probe tube placement and to provide a method to evaluate competency before starting clinical practicum placements. Two simulators were developed, an adult model and a pediatric model. PURPOSE To assess the face and content validity of the two probe tube placement simulators (adult and pediatric) and define barriers and facilitators to implementing this system into an educational setting. RESEARCH DESIGN Participants followed the setup and operating instructions designed to guide them through each functionality of the simulator. A questionnaire was used to assess face and content validity, applicability to an educational setting, and to determine perceived barriers and facilitators to using the probe tube simulators for training purposes. Five additional probe tube placements with each simulator were performed in which distance-to-TM was recorded. STUDY SAMPLE Twelve participants with significant probe tube placement experience. DATA COLLECTION AND ANALYSIS Participants rated each question in the questionnaire from 0% to 100% depending on their level of agreement. Averages and standard deviations (SDs) were compiled and presented for each section (face validity, content validity, and applicability to an educational setting). Final facilitators and barriers for the simulator were compiled and the top answers of each are presented. The five quantitative probe tube placement measurements for each participant were averaged, SDs were calculated, and contacts with the TM while placing the probe tube were recorded. RESULTS The average face validity score over all questions for the adult model was 65% (SD = 18.2) whereas the pediatric model received a score of 64% (16.4). The overall content validity average score was 78.7% (17) and applicability to an educational setting had an average score of 80% (5.33). The average distance-to-TM across all trials and participants was 3.74 mm (1.82) for the adult model and 2.77 mm (0.94) for the pediatric model with only one participant exceeding the recommended maximum of 5 mm. Listed shortcomings of the current simulator included realism of the 3D-printed ear, ease of insertion of an otoscope tip into the ear, ability to visualize the ear canal "landmarks" and the TM, and foam tip insertion experience. CONCLUSIONS Results were generally very positive for the simulator, and future iterations will look to improve the flexibility and texture of the ear, as well as the otoscopic view of the ear canal and TM.
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Iyer JS, Zhu N, Gasilov S, Ladak HM, Agrawal SK, Stankovic KM. Visualizing the 3D cytoarchitecture of the human cochlea in an intact temporal bone using synchrotron radiation phase contrast imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:3757-3767. [PMID: 30338153 DOI: 10.1364/boe.9.00375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/17/2018] [Accepted: 05/23/2018] [Indexed: 05/21/2023]
Abstract
The gold standard method for visualizing the pathologies underlying human sensorineural hearing loss has remained post-mortem histology for over 125 years, despite awareness that histological preparation induces severe artifacts in biological tissue. Historically, the transition from post-mortem assessment to non-invasive clinical biomedical imaging in living humans has revolutionized diagnosis and treatment of disease; however, innovation in non-invasive techniques for cellular-level intracochlear imaging in humans has been difficult due to the cochlea's small size, complex 3D configuration, fragility, and deep encasement within bone. Here we investigate the ability of synchrotron radiation-facilitated X-ray absorption and phase contrast imaging to enable visualization of sensory cells and nerve fibers in the cochlea's sensory epithelium in situ in 3D intact, non-decalcified, unstained human temporal bones. Our findings show that this imaging technique resolves the bone-encased sensory epithelium's cytoarchitecture with unprecedented levels of cellular detail for an intact, unstained specimen, and is capable of distinguishing between healthy and damaged epithelium. All analyses were performed using commercially available software that quickly reconstructs and facilitates 3D manipulation of massive data sets. Results suggest that synchrotron radiation phase contrast imaging has the future potential to replace histology as a gold standard for evaluating intracochlear structural integrity in human specimens, and motivate further optimization for translation to the clinic.
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Iyer JS, Zhu N, Gasilov S, Ladak HM, Agrawal SK, Stankovic KM. Visualizing the 3D cytoarchitecture of the human cochlea in an intact temporal bone using synchrotron radiation phase contrast imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:3757-3767. [PMID: 30338153 PMCID: PMC6191620 DOI: 10.1364/boe.9.003757] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/17/2018] [Accepted: 05/23/2018] [Indexed: 05/21/2023]
Abstract
The gold standard method for visualizing the pathologies underlying human sensorineural hearing loss has remained post-mortem histology for over 125 years, despite awareness that histological preparation induces severe artifacts in biological tissue. Historically, the transition from post-mortem assessment to non-invasive clinical biomedical imaging in living humans has revolutionized diagnosis and treatment of disease; however, innovation in non-invasive techniques for cellular-level intracochlear imaging in humans has been difficult due to the cochlea's small size, complex 3D configuration, fragility, and deep encasement within bone. Here we investigate the ability of synchrotron radiation-facilitated X-ray absorption and phase contrast imaging to enable visualization of sensory cells and nerve fibers in the cochlea's sensory epithelium in situ in 3D intact, non-decalcified, unstained human temporal bones. Our findings show that this imaging technique resolves the bone-encased sensory epithelium's cytoarchitecture with unprecedented levels of cellular detail for an intact, unstained specimen, and is capable of distinguishing between healthy and damaged epithelium. All analyses were performed using commercially available software that quickly reconstructs and facilitates 3D manipulation of massive data sets. Results suggest that synchrotron radiation phase contrast imaging has the future potential to replace histology as a gold standard for evaluating intracochlear structural integrity in human specimens, and motivate further optimization for translation to the clinic.
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Schart-Morén N, Hallin K, Agrawal SK, Ladak HM, Eriksson PO, Li H, Rask-Andersen H. Peri-operative electrically evoked auditory brainstem response assessment of facial nerve/cochlea interaction at cochlear implantation. Cochlear Implants Int 2018; 19:324-329. [DOI: 10.1080/14670100.2018.1481179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Abstract
Stapedectomy and stapedotomy represent the state-of-the-art surgical procedures in addressing the conductive hearing loss caused by otosclerosis. Their high rates of success and long-term stability have been demonstrated repeatedly in many studies. In comparing the short- and long-term results of the 2 procedures, it is evident that stapedotomy confers better hearing gain at high frequencies and lower complication rates. Modified stapes mobilization procedures may represent the next major development in stapes surgery in a selected patient population.
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Iyaniwura JE, Elfarnawany M, Ladak HM, Agrawal SK. An automated A-value measurement tool for accurate cochlear duct length estimation. J Otolaryngol Head Neck Surg 2018; 47:5. [PMID: 29357924 PMCID: PMC5778705 DOI: 10.1186/s40463-018-0253-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 01/08/2018] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND There has been renewed interest in the cochlear duct length (CDL) for preoperative cochlear implant electrode selection and postoperative generation of patient-specific frequency maps. The CDL can be estimated by measuring the A-value, which is defined as the length between the round window and the furthest point on the basal turn. Unfortunately, there is significant intra- and inter-observer variability when these measurements are made clinically. The objective of this study was to develop an automated A-value measurement algorithm to improve accuracy and eliminate observer variability. METHOD Clinical and micro-CT images of 20 cadaveric cochleae specimens were acquired. The micro-CT of one sample was chosen as the atlas, and A-value fiducials were placed onto that image. Image registration (rigid affine and non-rigid B-spline) was applied between the atlas and the 19 remaining clinical CT images. The registration transform was applied to the A-value fiducials, and the A-value was then automatically calculated for each specimen. High resolution micro-CT images of the same 19 specimens were used to measure the gold standard A-values for comparison against the manual and automated methods. RESULTS The registration algorithm had excellent qualitative overlap between the atlas and target images. The automated method eliminated the observer variability and the systematic underestimation by experts. Manual measurement of the A-value on clinical CT had a mean error of 9.5 ± 4.3% compared to micro-CT, and this improved to an error of 2.7 ± 2.1% using the automated algorithm. Both the automated and manual methods correlated significantly with the gold standard micro-CT A-values (r = 0.70, p < 0.01 and r = 0.69, p < 0.01, respectively). CONCLUSION An automated A-value measurement tool using atlas-based registration methods was successfully developed and validated. The automated method eliminated the observer variability and improved accuracy as compared to manual measurements by experts. This open-source tool has the potential to benefit cochlear implant recipients in the future.
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Koch RW, Ladak HM, Elfarnawany M, Agrawal SK. Measuring Cochlear Duct Length - a historical analysis of methods and results. J Otolaryngol Head Neck Surg 2017; 46:19. [PMID: 28270200 PMCID: PMC5341452 DOI: 10.1186/s40463-017-0194-2] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Accepted: 02/22/2017] [Indexed: 11/22/2022] Open
Abstract
Background Cochlear Duct Length (CDL) has been an important measure for the development and advancement of cochlear implants. Emerging literature has shown CDL can be used in preoperative settings to select the proper sized electrode and develop customized frequency maps. In order to improve post-operative outcomes, and develop new electrode technologies, methods of measuring CDL must be validated to allow usage in the clinic. Purpose The purpose of this review is to assess the various techniques used to calculate CDL and provide the reader with enough information to make an informed decision on how to conduct future studies measuring the CDL. Results The methods to measure CDL, the modality used to capture images, and the location of the measurement have all changed as technology evolved. With recent popularity and advancement in computed tomography (CT) imaging in place of histologic sections, measurements of CDL have been focused at the lateral wall (LW) instead of the organ of Corti (OC), due to the inability of CT to view intracochlear structures. After analyzing results from methods such as directly measuring CDL from histology, indirectly reconstructing the shape of the cochlea, and determining CDL based on spiral coefficients, it was determined the three dimensional (3D) reconstruction method is the most reliable method to measure CDL. 3D reconstruction provides excellent visualization of the cochlea and avoids errors evident in other methods. Due to the number of varying methods with varying accuracies, certain guidelines must be followed in the future to allow direct comparison of CDL values between studies. Conclusion After summarizing and analyzing the interesting history of CDL measurements, the use of standardized guidelines and the importance of CDL for future cochlear implant developments is emphasized for future studies.
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Ligorio G, Zanotto D, Sabatini AM, Agrawal SK. A novel functional calibration method for real-time elbow joint angles estimation with magnetic-inertial sensors. J Biomech 2017; 54:106-110. [PMID: 28236444 DOI: 10.1016/j.jbiomech.2017.01.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 01/15/2017] [Accepted: 01/17/2017] [Indexed: 11/18/2022]
Abstract
Magnetic-inertial measurement units (MIMUs) are often used to measure the joint angles between two body segments. To obtain anatomically meaningful joint angles, each MIMU must be computationally aligned (i.e., calibrated) with the anatomical rotation axes. In this paper, a novel four-step functional calibration method is presented for the elbow joint, which relies on a two-degrees-of-freedom elbow model. In each step, subjects are asked to perform a simple task involving either one-dimensional motions around some anatomical axes or a static posture. The proposed method was implemented on a fully portable wearable system, which, after calibration, was capable of estimating the elbow joint angles in real time. Fifteen subjects participated in a multi-session experiment that was designed to assess accuracy, repeatability and robustness of the proposed method. When compared against an optical motion capture system (OMCS), the proposed wearable system showed an accuracy of about 4° along each degree of freedom. The proposed calibration method was tested against different MIMU mountings, multiple repetitions and non-strict observance of the calibration protocol and proved to be robust against these factors. Compared to previous works, the proposed method does not require the wearer to maintain specific arm postures while performing the calibration motions, and therefore it is more robust and better suited for real-world applications.
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Elfarnawany M, Alam SR, Rohani SA, Zhu N, Agrawal SK, Ladak HM. Micro-CT versus synchrotron radiation phase contrast imaging of human cochlea. J Microsc 2016; 265:349-357. [PMID: 27935035 DOI: 10.1111/jmi.12507] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/29/2016] [Accepted: 10/30/2016] [Indexed: 11/26/2022]
Abstract
High-resolution images of the cochlea are used to develop atlases to extract anatomical features from low-resolution clinical computed tomography (CT) images. We compare visualization and contrast of conventional absorption-based micro-CT to synchrotron radiation phase contrast imaging (SR-PCI) images of whole unstained, nondecalcified human cochleae. Three cadaveric cochleae were imaged using SR-PCI and micro-CT. Images were visually compared and contrast-to-noise ratios (CNRs) were computed from n = 27 regions-of-interest (enclosing soft tissue) for quantitative comparisons. Three-dimensional (3D) models of cochlear internal structures were constructed from SR-PCI images using a semiautomatic segmentation method. SR-PCI images provided superior visualization of soft tissue microstructures over conventional micro-CT images. CNR improved from 7.5 ± 2.5 in micro-CT images to 18.0 ± 4.3 in SR-PCI images (p < 0.0001). The semiautomatic segmentations yielded accurate reconstructions of 3D models of the intracochlear anatomy. The improved visualization, contrast and modelling achieved using SR-PCI images are very promising for developing atlas-based segmentation methods for postoperative evaluation of cochlear implant surgery.
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Stepniak C, Wickens B, Husein M, Paradis J, Ladak HM, Fung K, Agrawal SK. Blinded randomized controlled study of a web-based otoscopy simulator in undergraduate medical education. Laryngoscope 2016; 127:1306-1311. [DOI: 10.1002/lary.26246] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 07/10/2016] [Accepted: 07/13/2016] [Indexed: 11/11/2022]
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Liu J, Agrawal SK, Ladak HM, Wan W. Fiber Arrangement in the Rat Tympanic Membrane. Anat Rec (Hoboken) 2016; 299:1531-1539. [PMID: 27532441 DOI: 10.1002/ar.23461] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 11/07/2022]
Abstract
The fiber arrangement in the pars tensa of the rat tympanic membrane (TM) was observed using a high resolution scanning electron microscope. The entire pars tensa is composed of fibrils with diameter of approximately 25 nm. These fibrils can be grouped into radial, circular, parabolic, and oblique fibers as reported in other mammals. The radial fibrils interweave into a planar form rather than into discrete cylindrical fibers. Before attaching to the manubrium and tympanic ring, the radial fibrils bend and cross neighboring fibrils to form a random fibril network, and change their direction from perpendicular to somewhat parallel to the manubrium and tympanic ring. The circular fibrils form cylindrical fibers near the peripheral part of the TM while closer to the manubrium, they form planar bundles. The observed fiber morphology and arrangement may provide helpful information in improving numerical models for the TM's acoustical response and designing a fibrous graft for the repair of TM perforations. Anat Rec, 299:1531-1539, 2016. © 2016 Wiley Periodicals, Inc.
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Rohani SA, Ghomashchi S, Umoh J, Holdsworth DW, Agrawal SK, Ladak HM. Iodine potassium iodide improves the contrast-to-noise ratio of micro-computed tomography images of the human middle ear. J Microsc 2016; 264:334-338. [PMID: 27439684 DOI: 10.1111/jmi.12447] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 06/21/2016] [Accepted: 06/30/2016] [Indexed: 12/11/2022]
Abstract
High-resolution imaging of middle-ear geometry is necessary for finite-element modeling. Although micro-computed tomography (microCT) is widely used because of its ability to image bony structures of the middle ear, it is difficult to visualize soft tissues - including the tympanic membrane and the suspensory ligaments/tendons - because of lack of contrast. The objective of this research is to quantitatively evaluate the efficacy of iodine potassium iodide (IKI) solution as a contrast agent. Six human temporal bones were used in this experiment, which were obtained in right-left pairs, from three cadaveric heads. All bones were fixed using formaldehyde. Three bones (one from each pair) were stained in IKI solution for 2 days, whereas the other three were not stained. Samples were scanned using a microCT system at a resolution of 20 μm. Eight soft tissues in the middle ear were segmented: anterior mallear ligament, incudomallear joint, lateral mallear ligament, posterior incudal ligament, stapedial annular ligament, stapedius muscle, tympanic membrane and tensor tympani muscle. Contrast-to-noise ratios (CNRs) of each soft tissue were calculated for each temporal bone. Combined CNRs of the soft tissues in unstained samples were 6.1 ± 3.0, whereas they were 8.1 ± 2.7 in stained samples. Results from Welch's t-test indicate significant difference between the two groups at a 95% confidence interval. Results for paired t-tests for each of the individual soft tissues also indicated significant improvement of contrast in all tissues after staining. Relatively large soft tissues in the middle ear such as the tympanic membrane and the tensor tympani muscle were impacted by staining more than smaller tissues such as the stapedial annular ligament. The increase in contrast with IKI solution confirms its potential application in automatic segmentation of the middle-ear soft tissues.
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Kao PC, Srivastava S, Higginson JS, Agrawal SK, Scholz JP. Short-term Performance-based Error-augmentation versus Error-reduction Robotic Gait Training for Individuals with Chronic Stroke: A Pilot Study. PHYSICAL MEDICINE AND REHABILITATION INTERNATIONAL 2015; 2:1066. [PMID: 27336075 PMCID: PMC4914051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The success of locomotion training with robotic exoskeletons requires identifying control algorithms that effectively retrain gait patterns in neurologically impaired individuals. Here we report how the two training paradigms, performance-based error-augmentation versus error-reduction, modified walking patterns in four chronic post-stroke individuals as a proof-of-concept for future locomotion training following stroke. Stroke subjects were instructed to match a prescribed walking pattern template derived from neurologically intact individuals. Target templates based on the spatial paths of lateral ankle malleolus positions during walking were created for each subject. Robotic forces were applied that either decreased (error-reduction) or increased (error-augmentation) the deviation between subjects' instantaneous malleolus positions and their target template. Subjects' performance was quantified by the amount of deviation between their actual and target malleolus paths. After the error-reduction training, S1 showed a malleolus path with reduced deviation from the target template by 16%. In contrast, S4 had a malleolus path further away from the template with increased deviation by 12%. After the error-augmentation training, S2 had a malleolus path greatly approximating the template with reduced deviation by 58% whereas S3 walked with higher steps than his baseline with increased deviation by 37%. These findings suggest that an error-reduction force field has minimal effects on modifying subject's gait patterns whereas an error-augmentation force field may promote a malleolus path either approximating or exceeding the target walking template. Future investigation will need to evaluate the long-term training effects on over-ground walking and functional capacity.
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Huang C, Cheng H, Bureau Y, Agrawal SK, Ladak HM. Face and content validity of a virtual-reality simulator for myringotomy with tube placement. J Otolaryngol Head Neck Surg 2015; 44:40. [PMID: 26481401 PMCID: PMC4615336 DOI: 10.1186/s40463-015-0094-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 10/12/2015] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Myringotomy with tube insertion can be challenging for junior Otolaryngology residents as it is one of the first microscopic procedures they encounter. The Western myringotomy simulator was developed to allow trainees to practice microscope positioning, myringotomy, and tube placement. This virtual-reality simulator is viewed in stereoscopic 3D, and a haptic device is used to manipulate the digital ear model and surgical tools. OBJECTIVE To assess the face and content validity of the Western myringotomy simulator. METHODS The myringotomy simulator was integrated with new modules to allow speculum placement, manipulation of an operative microscope, and insertion of the ventilation tube through a deformable tympanic membrane. A questionnaire was developed in consultation with instructing surgeons. Fourteen face validity questions focused on the anatomy of the ear, simulation of the operative microscope, appearance and movement of the surgical instruments, deformation and cutting of the eardrum, and myringotomy tube insertion. Six content validity questions focused on training potential on surgical tasks such as speculum placement, microscope positioning, tool navigation, ear anatomy, myringotomy creation and tube insertion. A total of 12 participants from the Department of Otolaryngology-Head and Neck Surgery were recruited for the study. Prior to completing the questionnaire, participants were oriented to the simulator and given unlimited time to practice until they were comfortable with all of its aspects. RESULTS Responses to 12 of the 14 questions on face validity were predominantly positive. One issue of concern was with contact modeling related to tube insertion into the eardrum, and the second was with the movement of the blade and forceps. The former could be resolved by using a higher resolution digital model for the eardrum to improve contact localization. The latter could be resolved by using a higher fidelity haptic device. With regard to content validity, 64% of the responses were positive, 21% were neutral, and 15% were negative. CONCLUSIONS The Western myringotomy simulator appears to have sufficient face and content validity. Further development with automated metrics and skills transference testing is planned.
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Glicksman JT, Khalili S, Fung K, Parnes LS, Agrawal SK. Pentoxifylline-tocopherol-clodronate combination: A novel treatment for osteoradionecrosis of the temporal bone. Head Neck 2015; 37:E191-3. [DOI: 10.1002/hed.24057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2015] [Indexed: 11/12/2022] Open
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Dahal S, Agrawal SK, Shrestha A, Bhagat TK. Self-perception regarding dental aesthetics, knowledge and attitude of traumatic dental injury and halitosis among people of Aurabani, Sunsari district of Eastern Nepal. JOURNAL OF COLLEGE OF MEDICAL SCIENCES-NEPAL 2015. [DOI: 10.3126/jcmsn.v11i1.13314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Background and Objectives: Increased concern over dental appearance has been observed during childhood and adolescence to early adulthood. The study was conducted with objectives to assess the self-perception of dental aesthetics, knowledge, attitude and management of dental trauma and halitosis.Materials and Methods: Self-administered questionnaire translated in Nepali language consisting of 32 questions was used. The completed questionnaires were analyzed using descriptive statistics.Results: Out of the total study population, 63% were satisfied with their overall tooth appearance and 71.7% with their tooth color. Twenty-nine percent had experienced dental trauma. More than half of the study population thought that immediate treatment was required after dental trauma. Fifty seven percent of the villagers had halitosis.Conclusion: The research clearly shows that the people of Aurabani VDC were satisfied with their tooth color and overall tooth appearance; however the knowledge regarding emergency management of dental trauma, the cause and management of halitosis was insufficient.JCMS Nepal. 2015;11(1):6-8
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Wickens B, Lewis J, Morris DP, Husein M, Ladak HM, Agrawal SK. Face and content validity of a novel, web-based otoscopy simulator for medical education. J Otolaryngol Head Neck Surg 2015; 44:7. [PMID: 25889997 PMCID: PMC4349665 DOI: 10.1186/s40463-015-0060-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/26/2015] [Indexed: 11/16/2022] Open
Abstract
Background Despite the fact that otoscopy is a widely used and taught diagnostic tool during medical training, errors in diagnosis are common. Physical otoscopy simulators have high fidelity, but they can be expensive and only a limited number of students can use them at a given time. Objectives 1) To develop a purely web-based otoscopy simulator that can easily be distributed to students over the internet. 2) To assess face and content validity of the simulator by surveying experts in otoscopy. Methods An otoscopy simulator, OtoTrain™, was developed at Western University using web-based programming and Unity 3D. Eleven experts from academic institutions in North America were recruited to test the simulator and respond to an online questionnaire. A 7-point Likert scale was used to answer questions related to face validity (realism of the simulator), content validity (expert evaluation of subject matter and test items), and applicability to medical training. Results The mean responses for the face validity, content validity, and applicability to medical training portions of the questionnaire were all ≤3, falling between the “Agree”, “Mostly Agree”, and “Strongly Agree” categories. The responses suggest good face and content validity of the simulator. Open-ended questions revealed that the primary drawbacks of the simulator were the lack of a haptic arm for force feedback, a need for increased focus on pneumatic otoscopy, and few rare disorders shown on otoscopy. Conclusion OtoTrain™ is a novel, web-based otoscopy simulator that can be easily distributed and used by students on a variety of platforms. Initial face and content validity was encouraging, and a skills transference study is planned following further modifications and improvements to the simulator.
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Arora BS, Sharma E, Agrawal SK, Agrawal M. In vitro cytotoxicity of methanol extract from aerial parts of Aralia cachemirica and purified continentalic acid. Indian J Pharm Sci 2015; 77:792-5. [PMID: 26997711 PMCID: PMC4778243 DOI: 10.4103/0250-474x.174980] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The present study was designed to evaluate the in vitro cytotoxic effect of methanol extract of aerial parts including stems, leaves and twigs of Aralia cachemirica and purified continentalic acid isolated from this extract against a panel of human cancer cell lines of varied tissues. Percentage of growth inhibition was evaluated by sulphorhodamine B assay. Purified continentalic acid showed moderate cytotoxicity against all the cell lines used. In contrast, the extract exhibited significant concentration dependant cytotoxicity against A-549 (lung), THP-1 (leukemia) and MCF-7 (breast) cell lines. This work highlights cytotoxic potential of this extract, which can further be explored for different constituents for their possible use autonomously or in combined manner in cancer therapy. The detailed analysis of their cytotoxicity has been presented in this paper.
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Glicksman JT, Khalili S, Fung K, Parnes LS, Agrawal SK. PENTOCLO for Treatment of Osteoradionecrosis of the Temporal Bone. Otolaryngol Head Neck Surg 2014. [DOI: 10.1177/0194599814541629a267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives: Osteoradionecrosis is a rare but devastating complication of radiation therapy that often requires surgical intervention. The objective of this report is to describe a case of osteoradionecrosis (ORN) of the temporal bone that was managed medically with PENTOCLO (pentoxifylline-tocopherol-clodronate). The use of PENTOCLO in the treatment of ORN of other sites in the head and neck will also be described. Methods: We report the case of a patient treated at our institution and present a review of literature. A 52-year-old woman presented with ORN of the temporal bone 20 years following radiation therapy for an ipsilateral parotid tumor. The patient had chronic infections and otorrhea. Results: She failed conservative treatment including antibiotic-steroid ear drops and aural lavage. As an alternative to hyperbaric oxygen and/or temporal bone resection, treatment with PENTOCLO was pursued and her condition improved dramatically. A literature review of ORN of the temporal bone and the use of PENTOCOLO in the management of ORN of other sites of the head and neck are described. Conclusions: PENTOCLO was effectively used in the management of our patient and may represent a valuable management option for other patients with ORN of the temporal bone. Further research is required to determine the effectiveness of PENTOCLO.
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Agrawal SK, Tikar S, Yadav R, Halve AK, Sathe M. The effect of aryl hydrazono ester containing dipeptides (AHEDs) on mosquito egg-laying behaviour. NEW J CHEM 2014. [DOI: 10.1039/c4nj00647j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fifteen peptide derivatives were synthesized to study oviposition responses in mosquitoes at two different concentrations. AHED-6 showed the maximum oviposition attractant activity while AHED-13 exhibited the highest oviposition deterrent activity.
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Agrawal SK, Panini P, Sathe M, Chopra D, Kaushik MP. Design and synthesis of cyclic depsipeptides containing triazole (CDPT) rings. RSC Adv 2014. [DOI: 10.1039/c3ra45100c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Lenzi T, Zanotto D, Stegall P, Carrozza MC, Agrawal SK. Reducing muscle effort in walking through powered exoskeletons. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2012:3926-9. [PMID: 23366786 DOI: 10.1109/embc.2012.6346825] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This paper presents a novel assistive control for lower limb exoskeletons. The controller provides the user with a scaled version of the Winter's nominal torque profile, which is adapted online to the specific gait features of the user. The proposed assistive controller is implemented on the ALEX II exoskeleton and tested on two healthy subjects. Experimental results show that when assisted by the exoskeleton users can reduce the muscle effort compared to free walking.
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