Browsing by Author "Nair, SS"

Now showing 1 - 8 of 8
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    Analysis of Whole Blood Prothrombin Time/ International Normalized Ratio Using Image Processing
    (Research in Medical and Engineering Sciences, 2021-03) Nair, SS; Rakhi, MR; Sadanandan, L; Harikrishnan, S; Bhatt, A
    Purpose: Patients who had undergone mechanical heart valve replacements, who have atrial fibrillation or deep vein thrombosis, need drugs called oral anticoagulants to prevent blood clotting and need regular testing of Prothrombin Time/International Normalized Ratio. Conventional laboratory approaches are time consuming, need blood component separation and a regular visit to clinical labs. The burden of PT measurement on the clinical laboratory is huge globally, which raise need for point of care, quick and user-friendly device. Methods: In this study we have proposed a handheld device based on the image processing for the PT/INR detection. Cost effective disposable strips were fabricated using thromboplastin as reagent. Device and strips were tested for 100 samples in clinical set up as per the ISO standard 17593 “Clinical laboratory testing and in vitro medical devices - Requirements for in vitro monitoring systems for self-testing of oral anticoagulant therapy”. Results: Data was compared with the values obtained from clinical laboratory using automated coagulometer T Coag DT-100 (Trinity), and commercially available Point of Care (POC) device from Roche, Diagnostics. A correlation coefficient (r) of 0.87 & 0.77 was observed between lab vs Chitra device and Chitra device vs commercially available device, respectively. Conclusion: Clinically accepted correlation may be obtained after automation of the strip fabrication technique. The proposed device is cost effective and easy to operate and works on the novel approach of image processing. To best of our knowledge this is the first report on the image processing-based PT/INR monitoring device.
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    Autoimmune encephalitis: Clinical diagnosis versus antibody confirmation
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2015) Cyril, AC; Nair, SS; Mathai, A; Kannoth, S; Thomas, SV
    Context: Autoimmune encephalitis is a heterogeneous disorder which is being diagnosed with increasing frequency. The diagnosis of these disorders is based on the detection of autoantibodies and characteristic clinical profiles. Aims: We aimed to study the antibody profile in encephalitis patients with suspected autoimmune etiology presenting to a tertiary care center. Settings and Design: The subjects were selected by screening all patients with clinical profile suggesting autoimmune encephalitis admitted in the neuromedical intensive care unit (ICU) of a tertiary care center in South India. Materials and Methods: Patients who fulfilled modified Zuliani et al.'s, criteria for autoimmune encephalitis were identified during the period December 2009-June 2013. Blood samples from these subjects were screened for six neuronal antibodies. Statistical analysis used: Chi-square test was applied to compare the antibody positive and negative patients. Results: Out of 1,227 patients screened, 39 subjects (14 males: 25 females) were identified with a mean age of 15.95 years and 19 cases were assessed in the acute and 20 in the convalescent phase of the illness. Seizure (87.8 %) was the most common presenting symptom; status epilepticus occurred in 23 (60.5%) patients during the course of the illness. Fourteen (35.9%) patients were N-methyl-D-aspartate receptor (NMDAR) antibody-positive and all were negative for the other antibodies tested. Conclusions: One-third of patients presenting with acute noninfective encephalitis would be positive for NMDAR antibodies with the remaining two-thirds with clinically suspected autoimmune encephalitis being antibody-negative. There are few markers in the clinical and investigative profiles to distinguish antibody-positive and -negative patients.
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    Design and Evaluation of Chitra Swab Collection Booths for Health Professionals in COVID-19 Pandemic
    (Transactions of the Indian National Academy of Engineering, 2020-12) Prajapati, AK; Nair, SS; Venkatesan, RB; Muraleedharan, CV; Kishore, A
    The 2019 novel coronavirus (SARS-CoV-2), officially named as COVID-19 by the WHO, has spread to more than 180 countries and the confirmed coronavirus cases have reached around 10 million with 0.6 million deaths by end of June 2020. Moreover, there is no sign of a sustained decline in any country till date. Continuous rise of positive cases has instilled fear in people, society and even health professionals. According to WHO’s daily situation report, 22,073 COVID-19 cases of healthcare professionals have been reported to the WHO as of Wednesday, 8 April 2020 by Jin (Mil Med Res 7:24, 2020). Infection to health professionals is a serious concern not only because they are a valuable frontline worker but also because of the risk of spread to co-workers and non-Covid patients. This project was undertaken to develop a solution to minimize the chance of infection to the health care professionals by providing them isolation from a potential source of Covid-19 and similar highly contagious diseases. The two models of Chitra swab collection booth were developed to: (1) protect health professionals from the risk of infection (2) to provide technical know-how to manufacturers to produce booths using locally available materials while meeting international regulations and (3) reduce the consumption of personal protective equipment. The prototypes developed were tested for safety and efficacy in accordance with the guidelines of the Centers for Disease Control and Prevention, Atlanta, USA. The device received the registration for commercialisation from the Central Drugs Control Standard Organization, Ministry of Health, Government of India, as a non-notified medical device.
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    Design of Electromagnetic Probe Having Reduced Base Line Drift for Blood Flow Measurement
    (IETE JOURNAL OF RESEARCH, 2015) Nair, SS; Vinodkumar, V; Sreedevi, V; Nagesh, DS
    An improved design for electromagnetic probe for blood flow measurement is presented. The probe produces a magnetic field in the column of blood to induce a voltage as per Faraday's laws. The mechanical and electromagnetic structures are designed to reduce the effect of base line drift and signal variations with time which are very common in electromagnetic flow measurement systems. A signal with very less noise and drift is induced with a sensitivity of more than 80 mV/lpm. The signal has a linear variation with flow rates and need no frequent calibration. Signal variations with time are negligible and had less power signal interferences and noisy spikes.
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    Metabolic syndrome in young adults with epilepsy
    (SEIZURE-EUROPEAN JOURNAL OF EPILEPSY, 2016) Nair, SS; Harikrishnan, S; Sarma, PS; Thomas, SV
    Purpose: Persons with epilepsy have higher cardiovascular mortality and morbidity compared to general population and alteration of their biochemical milieu is one of the proposed mechanisms. We aimed to study the prevalence of metabolic syndrome and cardiovascular risk factors in young adults with epilepsy and the association with antiepileptic drug use. Method: An observational study was conducted in persons with epilepsy aged 20-49 years using antiepileptic drugs regularly for the previous three years. The subjects were examined and their blood samples were collected for fasting blood glucose and lipid profile. Results: Over 18 months, 183 patients (120 males; 63 females) were recruited (mean age 32.5 +/- 8.9 years). Metabolic syndrome (MetS) by ATP III criteria was present in 54 (29.5%) subjects. People with MetS in our group had higher frequency of abdominal obesity (50.0%) and hypertriglyceridemia (55.5%) than diabetes/impaired fasting glucose (27.8%). Older age (p = 0.005) and use of valproate (p = 0.012) were associated with significant risk of MetS. Conclusion: Clinicians need to be vigilant regarding the risk of MetS while initiating treatment and following up persons with epilepsy. (C) 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
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    Persistent post-stroke dysphagia treated with cricopharyngeal myotomy
    (ANNALS OF INDIAN ACADEMY OF NEUROLOGY, 2016) Nair, SS; Surendaran, AJ; Menon, JR; Sreedharan, SE; Sylaja, PN
    Post-stroke dysphagia is a common problem after stroke. About 8-13% patients have persistent dysphagia and are unable to return to pre-stroke diet even after 6 months of stroke. Use of percutaneous endoscopic gastrostomy (PEG) may be required in these patients, which may be psychologically unacceptable and impair the quality of life. In those with cricopharyngeal dysfunction leading on to refractory post-stroke dysphagia, cricopharyngeal myotomy and injection of botulinum toxin are the treatment options. We present a case of vertebrobasilar stroke who had persistent dysphagia due to cricopharyngeal dysfunction with good recovery of swallowing function following cricopharyngeal myotomy 1.5 years after the stroke.
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    Rotating permanent magnet excitation for blood flow measurement
    (MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING, 2015) Nair, SS; Vinodkumar, V; Sreedevi, V; Nagesh, DS
    A compact, portable and improved blood flow measurement system for an extracorporeal circuit having a rotating permanent magnetic excitation scheme is described in this paper. The system consists of a set of permanent magnets rotating near blood or any conductive fluid to create high-intensity alternating magnetic field in it and inducing a sinusoidal varying voltage across the column of fluid. The induced voltage signal is acquired, conditioned and processed to determine its flow rate. Performance analysis shows that a sensitivity of more than 250 mV/lpm can be obtained, which is more than five times higher than conventional flow measurement systems. Choice of rotating permanent magnet instead of an electromagnetic core generates alternate magnetic field of smooth sinusoidal nature which in turn reduces switching and interference noises. These results in reduction in complex electronic circuitry required for processing the signal to a great extent and enable the flow measuring device to be much less costlier, portable and light weight. The signal remains steady even with changes in environmental conditions and has an accuracy of greater than 95 %. This paper also describes the construction details of the prototype, the factors affecting sensitivity and detailed performance analysis at various operating conditions.
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    Tumefactive demyelinating lesions: A Clinicopathological correlative study
    (INDIAN JOURNAL OF PATHOLOGY AND MICROBIOLOGY, 2012) Neelima, R; Krishnakumar, K; Nair, MD; Kesavadas, C; Hingwala, DR; Radhakrishnan, VV; Nair, SS
    Tumefactive demyelinating (TDL) lesions are focal zones of demyelination in the central nervous system and they often mimic the neuroimaging features of an intraxial neoplasm. In this report we describe the clinical, neuroimaging and neuropathological features of six cases of TDL. Only in two patients the neuroimaging features in MRI (magnetic resonance imaging) scans were suggestive of TDL while in the other four cases a diagnosis of glioma was suggested. In order to establish a confirmatory diagnosis neuronavigation/stereotactic biopsy was undertaken and the diagnosis of TDL was established in all six cases at histopathology. Two out of six patients did not respond to the conventional corticosteroid therapy and they were treated with plasma exchange. It is being concluded that neuronavigation biopsy, though provide only a small amount of tissue, and is extremely useful in making the diagnosis of TDL.