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H K Verma

Publications and source records attributed to H K Verma.

6 recordsLinked to original sources
PubMed2006

Adaptive threshold-based block classification in medical image compression for teleradiology.

Telemedicine, among other things, involves storage and transmission of medical images, popularly known as teleradiology. Due to constraints on bandwidth and storage capacity, a medical image may be needed to be compressed before transmission/storage. Among various compression techniques, transform-based techniques that convert an image in spatial domain into the data in spectral domain are very effective. Discrete cosine transform (DCT) is possibly the most popular transform used in compression of images in standards like Joint Photographic Experts Group (JPEG). In DCT-based compression the image is split into smaller blocks for computational simplicity. The blocks are classified on the basis of information content to maximize compression ratio without sacrificing diagnostic information. The present paper presents a technique along with computational algorithm for classification of blocks on the basis of an adaptive threshold value of variance. The adaptive approach makes the classification technique applicable across the board to all medical images. Its efficacy is demonstrated by applying it to CT, X-ray and ultrasound images and by comparing the results against the JPEG in terms of various objective quality indices.

Algorithms↗
PubMed2006

Enhancement of ethyl propionate synthesis by poly (AAc-co-HPMA-cl-MBAm)-immobilized Pseudomonas aeruginosa MTCC-4713, exposed to Hg2+ and NH4+ ions.

A purified alkaline thermo-tolerant bacterial lipase from Pseudomonas aeruginosa MTCC-4713 was immobilized on a poly (AAc-co-HPMA-cl-MBAm) hydrogel. The hydrogel-bound lipase achieved 93.6% esterification of ethanol and propionic acid (300 mM: 100 mM) into ethyl propionate at temperature 65 degrees C in 3 h in the presence of a molecular sieve (3 angstroms). In contrast, hydrogel-immobilized lipase pre-exposed to 5 mM of HgCl2 orNH4Cl resulted in approximately 97% conversion of reactants in 3 h into ethyl propionate under identical conditions. The salt-exposed hydrogel was relatively more efficient in repetitive esterification than the hydrogel-bound lipase not exposed to any of the cations. Moreover, bound lipase exposed Hg2+ or NH4+ ions showed altered specificity towards p-nitrophenyl esters and was more hydrolytic towards higher C-chain p-nitrophenyl esters (p-nitrophenyl laurate and p-nitrophenyl palmitate with C 12 and C 16 chain) than the immobilized lipase not exposed to any of the salts. The later showed greater specificity towards p-nitrophenyl caprylate (C 8).

Acrylamides↗
PubMed1999

Pharmacokinetics and dosage regimen of enrofloxacin in buffalo bulls after intramuscular administration.

The disposition kinetics and dosage regimen of enrofloxacin were investigated in breeding buffalo bulls following a single intramuscular administration of 5 mg/kg. The absorption half-life, half-life of the terminal phase, apparent volume of distribution and total body clearance were 0.262+0.099 h, 1.97+/-0.23 h, 0.61+/-0.13 L/kg and 210.2+/-18.6 ml/(kg.h), respectively. Therapeutic plasma levels (> or = 1 microg/ml) were maintained for up to 6 h. A satisfactory intramuscular dosage regimen for enrofloxacin in buffalo bulls would be 8.5 mg/kg followed by 8.0 mg/kg at 8 h intervals.

Animal Husbandry↗
PubMedDate not supplied

Diagnostic acceptability of FFT-based ECG data compression.

There are three signal domains in which ECG data compression can be performed, namely time domain, frequency domain and parameter extraction. The present paper deals with the frequency domain method of compression using fast Fourier transform. The algorithm has been tested on the third set of the CSE database library. A performance evaluation has been made using two important parameters, namely compression ratio and percent root-mean-square difference besides visual comparison. Further, in order to know the clinical acceptable quality of the reconstructed signal peak, boundary and interval measurements were made both on the reconstructed and the original signal of the same record for comparison. The visual examination reveals that most of the noise in the original signal had been filtered out during the compression. This amounts to reduction of electromyographic noise to a considerable extent. The experimental observations show that a compression ratio of 8 is feasible while ensuring clinical acceptability.

Algorithms↗
PubMedDate not supplied

ANN-based QRS-complex analysis of ECG.

Reliable detection the QRS complex in either a normal or an abnormal ECG and its analysis is the first and foremost task in almost every ECG signal analysis system aimed at the diagnostic interpretation of ECG. Conventionally, detection of the QRS complex is accomplished using a rule-based/algorithmic approach. This work, uses the learn and generalize approach of an artificial neural network (ANN) for the detection of QRS complexes in either a normal or an abnormal ECG. This is followed by the analysis of the QRS complex to designate and measure the morphological components within the QRS complex in all 12 standard leads. An ANN has been developed to detect the QRS complex in ECG and trained, with the help of back propagation algorithm, on more than a hundred ECGs selected from the CSE Data Set-3. The trained ANN was tested on all the recordings of the CSE Data Set-3 and the sensitivity has been found to be 99.11%. Subsequent to the identification of the QRS complex, an analysis of this complex and measurement of peak amplitudes of the component waves is done. The results are validated using the CSE multilead measurement results. Both the QRS detection and the QRS analysis software developed in C-language have been successfully implemented on a PC-AT. The results are found to be in agreement with visual measurements carried out by medical experts.

Electrocardiography↗