1.A compact-sized surface EMG sensor for myoelectric hand prosthesis
Alok PRAKASH ; Shiru SHARMA ; Neeraj SHARMA
Biomedical Engineering Letters 2019;9(4):467-479
Myoelectric prosthesis requires a sensor that can reliably capture surface electromyography (sEMG) signal from amputees for its controlled operation. The main problems with the presently available EMG devices are their extremely high cost, large response time, noise susceptibility, less amplitude sensitivity, and larger size. This paper proposes a compact and affordable EMG sensor for the prosthetic application. The sensor consists of an electrode interface, signal conditioning unit, and power supply unit all encased in a single package. The performance of dry electrodes employed in the skin interface was compared with the conventional Ag/AgCl electrodes, and the results were found satisfactory. The envelope detection technique in the sensor based on the tuned RC parameters enables the generation of smooth, faster, and repeatable EMG envelope irrespective of signal strength and subject variability. The output performance of the developed sensor was compared with commercial EMG sensor regarding signal-to-noise ratio, sensitivity, and response time. To perform this, EMG data with both devices were recorded for 10 subjects (3 amputees and 7 healthy subjects). The results showed 1.4 times greater SNR values and 45% higher sensitivity of the developed sensor than the commercial EMG sensor. Also, the proposed sensor was 57% faster than the commercial sensor in producing the output response. The sEMG sensor was further tested on amputees to control the operation of a self-designed 3D printed prosthetic hand. With proportional control scheme, the myoelectric hand setup was able to provide quicker and delicate grasping of objects as per the strength of the EMG signal.
Amputees
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Electric Power Supplies
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Electrodes
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Electromyography
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Hand Strength
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Hand
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Humans
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Noise
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Prostheses and Implants
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Reaction Time
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Signal-To-Noise Ratio
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Skin
2.Is hypothalamic involvement truly a red flag for multiple sclerosis?
Chandra Mohan Sharma ; Alok Jain ; BL Kumawat ; Dinesh Khandelwal ; Deepak Jain
Neurology Asia 2013;18(3):323-325
Any hypothalamic disturbance manifesting clinically is considered a major red flag for multiple
sclerosis, whereas MRI lesions involving deep grey matter structures are considered an intermediate
red flag. However, hypothalamic lesions manifesting clinically with hypersomnia have been described
in some patients of multiple sclerosis. We report a case where the first and presenting feature of
multiple sclerosis was acute onset hypersomnia with bilateral hypothalamic lesions. On review of
recent literature, we also question whether clinical or radiological hypothalamic involvement is really
so unusual that it should be considered a red flag for multiple sclerosis
3.Arteriovenous Fistula of the Filum Terminale Misdiagnosed and Previously Operated as Lower Lumbar Degenerative Disease.
Pankaj SHARMA ; Alok RANJAN ; Rahul LATH
Asian Spine Journal 2014;8(3):365-370
Filum terminale arteriovenous fistula (FTAVF) presenting as a cause of failed back surgery syndrome is a rare entity. We report a 48-year-old male patient who presented with clinical features of a conus medullaris/cauda equina lesion. He had upper and lower motor neuron signs in both the lower limbs with autonomic dysfunction. The patient was misdiagnosed and was operated twice earlier for lumbar canal stenosis and disc prolapse. After reviewing his clinical and radiological findings a diagnosis of FTAVF was made. He underwent surgery and there was a significant improvement in his neurological functions. We discuss the case and review the literature on FTAVF's.
Arteriovenous Fistula*
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Cauda Equina*
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Constriction, Pathologic
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Conus Snail
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Diagnosis
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Failed Back Surgery Syndrome
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Humans
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Lower Extremity
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Male
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Middle Aged
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Motor Neurons
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Prolapse
4.Greater palatine foramen--key to successful hemimaxillary anaesthesia: a morphometric study and report of a rare aberration.
Namita Alok SHARMA ; Rajendra Somnath GARUD
Singapore medical journal 2013;54(3):152-159
INTRODUCTIONAccurate localisation of the greater palatine foramen (GPF) is imperative while negotiating the greater palatine canal for blocking the maxillary nerve within the pterygopalatine fossa. The aim of this study was to define the position of the foramen relative to readily identifiable intraoral reference points in order to help clinicians judge the position of the GPF in a consistently reliable manner.
METHODSThe GPF was studied in 100 dried, adult, unsexed skulls from the state of Maharashtra in western India. Measurements were made using a vernier caliper.
RESULTSThe mean distances of the GPF from the midline maxillary suture, incisive fossa, posterior palatal border and pterygoid hamulus were 14.49 mm, 35.50 mm, 3.40 mm and 11.78 mm, respectively. The foramen was opposite the third maxillary molar in 73.38% of skulls, and the direction in which the foramen opened into the oral cavity was found to be most frequently anteromedial (49.49%). In one skull, the greater and lesser palatine foramina were bilaterally absent. Except for the invariably present incisive canals, there were no accessory palatal foramina, which might have permitted passage of the greater palatine neurovascular bundle in lieu of the absent GPF. To the best of our knowledge, this is the first study of such a non-syndromic presentation.
CONCLUSIONThe GPF is most frequently palatal to the third maxillary molar. For an edentulous patient, the foramen may be located 14-15 mm from the mid-palatal raphe or about 12 mm anterior to the palpable pterygoid hamulus.
Anesthesia ; methods ; Cadaver ; Humans ; India ; Maxilla ; anatomy & histology ; innervation ; Maxillary Nerve ; pathology ; Molar ; anatomy & histology ; Palate, Hard ; abnormalities ; anatomy & histology ; innervation ; Reference Values ; Skull ; anatomy & histology
5.Clinical Applications of 68Ga-PSMA PET/CT on Residual Disease Assessment of Juvenile Nasopharyngeal Angiofibroma (JNA)
Pirabu SAKTHIVEL ; Alok THAKAR ; Arun PRASHANTH ; Meivel ANGAMUTHU ; Suresh Chandra SHARMA ; Rakesh KUMAR
Nuclear Medicine and Molecular Imaging 2020;54(1):63-64
We present a case of a 16-year-old boy who underwent 68Ga-PSMA PET/CT for residual disease assessment of juvenile nasal angiofibroma. Positive uptake was noted in residual tumor on PET/CT imaging. However, there was no abnormal uptake in surrounding scar tissues as compared with contrast-enhanced magnetic resonance imaging. These findings were confirmed by biopsy from the scar tissue on posterior ethmoids. 68Ga-PSMA PET/CT may be a potentially valuable tool especially in distinguishing recurrences from surgical site reparative tissue and in planning and delivering stereotactic radiotherapy.
6.Early Infant Feeding Practices May Influence the Onset of Symptomatic Celiac Disease.
Shailja VAJPAYEE ; Shiv Dayal SHARMA ; Rajkumar GUPTA ; Alok GOYAL ; Aakash SHARMA
Pediatric Gastroenterology, Hepatology & Nutrition 2016;19(4):229-235
PURPOSE: To study whether breastfeeding and breastfeeding status during gluten introduction influences the age at diagnosis of celiac disease (CD). In addition to study, whether the timing of gluten introduction influences the age at diagnosis of CD. METHODS: It was a hospital based observational study. Total 198 patients diagnosed with CD as per modified European Society of Pediatric Gastroenterology, Hepatology and Nutrition (2012) criteria, aged between 6 months to 6 years were included. Detail history taken with special emphasis on breastfeeding and age of gluten introduction. Standard statistical methods used to analyze the data. RESULTS: Mean±standard deviation age of onset and diagnosis of CD in breastfed cases was 2.81±1.42 years and 3.68 ±1.55 years respectively as compared to 1.84±1.36 years and 2.70±1.65 years respectively in not breastfed cases (p<0.05). Those who had continued breastfeeding during gluten introduction and of longer duration had significantly delayed onset of disease. The age at onset of CD was under one year in 40.42% of the cases, who had started gluten before 6 months of age compared to only 12.58% of those who had started gluten later (p<0.001). The proposed statistical model showed that two variables, i.e., breast feeding status during gluten introduction and age at gluten introduction positively influencing the age at diagnosis of CD. CONCLUSION: Delayed gluten introduction to infant's diet along with continuing breastfeeding, delays symptomatic CD. However, it is not clear from our study that these infant feeding practices provide permanent protection against the disease or merely delays the symptoms.
Age of Onset
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Breast Feeding
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Celiac Disease*
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Diagnosis
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Diet
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Gastroenterology
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Glutens
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Humans
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Infant*
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Models, Statistical
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Observational Study
7.Objective Comparison of Benefits Derived From Contralateral Routing of Signal Hearing Aid and Bone Conduction Device in Noisy Surroundings in Patients With Single-Sided Deafness
Kapil SIKKA ; Rijendra YOGAL ; Alok THAKAR ; Rakesh KUMAR ; Tanvi CHAUDHARY ; Mao BHARTIYA ; Hitesh VERMA ; Sonam SHARMA ; Chirom Amit SINGH
Journal of Audiology & Otology 2022;26(4):202-207
Background and Objectives:
Single-sided deafness (SSD) leads to non-participation of the diseased ear in generating adequate auditory input, which results in poor speech discrimination in noisy surroundings. The present study objectively compared the audiological benefits rendered by contralateral routing of signal (CROS) hearing aid and bone conduction device (BCD) in patients with SSD >70 dB HL using the modified hearing in noise test (HINT).
Materials and Methods:
Patients with SSD >70 dB HL in poor and clinically normal hearing in the better ear were enrolled. Patients aged <18 or >70 years, with a history of neurological insult or ear infection in the last 3 months, mental retardation, psychiatric or developmental disorders, and diabetes were excluded. Modified HINT was performed with the affected ear unaided, aided with CROS hearing aid, and with BCD, generating three groups. Noise signal was presented at a fixed intensity of 65 dB at the neutral position in the center and speech signal was presented to either ear sequentially. The test was repeated with the speech signal fixed at the neutral position and the noise signal presented to either ear.
Results:
BCD led to a better signal-to-noise ratio (SNR) than CROS hearing aid in all situations except when noise was centralized and speech was presented to the affected ear.
Conclusions
A benefit was observed when auditory rehabilitation was used for the affected ear as demonstrated by better SNR scores. The results showed that BCD performed better than CROS hearing aid.
8.Clinical and Social Outcomes of Cochlear Implantation in Older Prelinguals
Pragya TYAGI ; Divya CHAUHAN ; Anup SINGH ; Mayank BHUTADA ; Kapil SIKKA ; Tanvi CHAUDHARY ; Sonam SHARMA ; Shivani AGARWAL ; Hitesh VERMA ; Prem SAGAR ; Rakesh KUMAR ; Alok THAKAR
Journal of Audiology & Otology 2023;27(2):63-70
Background and Objectives:
Cochlear implantation in late implanted prelinguals necessitates a complex decision-making process for clinicians and patients due to the uncertainty of achieving adequate benefit in auditory and speech perception. This study longitudinally evaluated clinical and social outcomes of prelingually deaf children with implantation in their late childhood.
Subjects and Methods:
A total of 113 (49 females and 64 males) participants, with an age range of 5-15 years, were assessed for the pre-implant parameters such as hearing loss etiology, aided responses, anatomical aspects, and psychological evaluation. The Category of Auditory Performance, Speech Awareness Threshold, Speech Reception Threshold, and Speech Discrimination Score were administered to assess the patient’s auditory skills. Further, the Speech Intelligibility Rating scale was administered to evaluate the patient’s speech intelligibility at 3, 6, 9, 12, 18, and 24 months post-surgery. Subjectively perceived benefits were evaluated using the satisfaction rating scale and a questionnaire.
Results:
The statistical results showed a significant impact of cochlear implantation in all domains. Positive impact and improvement post-implantation were noted in all the spheres, including auditory, linguistic, social, and educational.
Conclusions
The study highlighted that the outcomes of a cochlear implant at a later age might not parallel with the implantation at a younger age. However, this still provides measurable benefits even after a longer period of auditory deprivation.
9.Is Regular Probiotic Practice Safe for Management of Sepsis?
Rishabh KUMAR ; Alok Shiomurti TRIPATHI ; Nidhi SHARMA ; Gaaminepreet SINGH ; Lucy MOHAPATRA
Chinese journal of integrative medicine 2022;28(2):185-192
For decades, the gut has been thought to play an important role in sepsis pathogenesis. Sepsis is a serious life-threatening, chronic condition of an infection caused by dysregulated host immune response in most of the intensive care unit patients. Probiotics have dual roles in polymicrobial sepsis i.e. probiotics may induce sepsis in many cases and may prevent its prognosis in many cases. Experimental evidence from both pre-clinical and clinical studies have demonstrated that probiotic therapy ameliorates various inflammatory mediators such as tumor necrosis factor, interleukin-10 (IL-10), IL-6, etc., in septicemia. In addition, probiotic use was also found to reduce the severity of pathological conditions associated with irritable bowel disorder and prevent development of endocarditis in septicemia. On contrary, probiotic therapy in neonatal and athymic adult mice fail to provide any beneficial effects on mortality and sepsis-induced inflammation. Importantly, in few clinical trials probiotic use was found to aggravate sepsis by promoting inflammatory cascade rather than suppressing it. This review discusses various studies regarding the beneficial or harmful effects associated with probiotic therapy in sepsis.
Animals
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Humans
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Inflammation
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Mice
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Probiotics/therapeutic use*
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Sepsis/therapy*
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Tumor Necrosis Factor-alpha
10.Quality by Design approach for the investigation of critical characteristics of Phyllanthus emblica from different vicinities
Prakash Ramakrishnan ; Priya Masand ; Pooja Dhama ; Anurag ; Sunil Gupta ; Alok Sharma
Digital Chinese Medicine 2023;6(3):272-284
[Objective] To explore the application of Quality by Design (QbD) tools in assessing geographical variations of Phyllanthus emblica (P. emblica) from five distinct Indian states.
[Methods] In the current experiment, the Box-Behnken design with a reduced quartic model and 105 runs was employed with the use of the Design Expert software for randomized response surface mapping. Three different extraction methods (Soxhlet, maceration, and sonication) along with three solventst [distilled water, methanol, and water-methanol mixture (50 : 50 v/v)] were considered in the present study. The anti-oxidant activities, total flavonoid content (TFC), and total phenolic content (TPC) in the P. emblica were determined and analysed by gas chromatography-mass spectrometry (GC-MS) to identify the major components.
[Results] The QbD overlay plot showed that the extractive value of the P. emblica was no less than 30% w/w, 2,2-diphenyl-1-picrylhydrazyl (DPPH) no less than 60% mcg/mL (micrograms per millilitre), TFC no less than 75 mg QE/g (milligrams of quercetin equivalents per gram), and TPC no less than 80 mg GAE/g (milligrams of gallic acid equivalents per gram). Moreover, the GC-MS data confirmed the presence of variation in the bioactives of P. emblica extracts.
[Conclusion] The model was significant in describing the variation in extractive value, DPPH, TFC, and TPC. The QbD approach may tend to prioritize thoroughness in the extraction process, ultimately resulting in improved quality in the extracted products.