PubMed Health⌕ Search

Biomedical subjects

B Ramamurthi

Publications and source records attributed to B Ramamurthi.

At least 19 recordsLinked to original sources
PubMed1990

Vector quantization for compression of multichannel ECG.

We propose a scheme based on vector quantization (VQ) for the data-compression of multichannel ECG waveforms. N-channel ECG is first coded using m-AZTEC, a new, multichannel extension of the AZTEC algorithm. As in AZTEC, the waveform is approximated using only lines and slopes; however, in m-AZTEC, the N-channels are coded simultaneously into a sequence of N + 1 dimensional vectors, thus exploiting the correlation that exists across channels in the AZTEC duration-parameter. Classified vector quantization (CVQ) of the m-AZTEC output is next performed to exploit the correlation in the other AZTEC parameter, namely, the value-parameter. CVQ preserves the waveform morphology by treating the lines and slopes as two perceptually-distinct classes. Both m-AZTEC and CVQ provide data-compression and their performance improves as the number of channels increases. Moreover, the final output differs little from the AZTEC output and hence ought to enjoy the same acceptability.

Algorithms↗
PubMed1989

Intracerebral hematoma following evacuation of chronic subdural hematoma.

The prognosis after evacuation of a chronic subdural hematoma is generally good, yet occasionally post-operative complications do occur. Intracerebral hematoma following such evacuation is rare and two cases are reported. It is suggested that this complication could be due to the disturbances of intracerebral vascular homeostasis occurring after rapid evacuation of subdural hematomas where there has been a large shift of the brain stem.

Aged↗
PubMed1989

International neurosurgery: neurosurgical training and practice in India, Korea, Japan, and Australasia.

During the 1985 annual meeting of the Congress of Neurological Surgeons in Honolulu, neurosurgical training and practice in India, Korea, Japan, and Australasia were discussed at the International Committee symposium. This article summarizes the information presented. India has about 300 neurosurgeons for a population of 650 million, while Japan has about 4,000 neurosurgeons and trainees for a population of 120 million. Korea has 424 neurosurgeons for a population of 41.5 million, and Australasia has 92 neurosurgeons and 19 trainees for 17.5 million people. Various other demographic, institutional, organizational, and economic aspects of neurological health care and delivery, education, and quality control are described. While financing and availability of adequate neurosurgical care remains a major problem in India, it appears that reducing the number of neurosurgical trainees remains, as it is in North America, a major issue in Japan and, to a lesser extent, in Korea. This problem, as well as certification of the quality of training, is being managed effectively in Australasia.

Asia↗
PubMed1988

Stereotactic operation in behaviour disorders. Amygdalotomy and hypothalamotomy.

After a survey of the anatomical and physiological basis of operative treatment of behaviour disorders by stereotactic lesions in the amygdala and the posterior medial hypothalamus the author describes his own experiences with 603 operations for control of conservatively untreatable aggressiveness. In 481 cases bilateral amygdalotomies and in 122 mostly secondary posteromedian hypothalamotomies have been performed. Initially excellent or moderate improvement was achieved in 76%. After a follow-up of more than three years this figure only slightly decreased to 70%. The group of patients who did not positively respond (30%) needs further study to discover the reasons for failure.

Adolescent↗
PubMed1988

Ethics of functional neurosurgery.

With the precision and accuracy available for modern techniques, operations on the brain for alleviating psychiatric disorders have become safer and reliable. Anxiety and feelings of doubt amongst the public about these procedures need to be dispelled. There is a need to compile accurate clinical and scientific data with careful follow up to assess the present status of functional neurosurgery and to ensure further progress.

Ethics, Medical↗
PubMed1986

Changing concepts in the treatment of tuberculomas of the brain.

Tuberculomas of the brain in children constitute 5% to 8% of intracranial space-occupying lesions in developing countries. These have in the past been treated with antituberculous drugs and with excision of large masses when the intracranial tension was high. Computed tomography (CT) has modified this approach. CT has resulted in earlier diagnosis and has been of help in monitoring the results of medical treatment of tuberculomas in children. With such monitoring there has been less need for surgical excision. At the same time, it has been realised that some caution is required towards our dependence on CT, as the image morphology of a tuberculoma could simulate other lesions like a glioma, and surgical excision needs to be carried out when in doubt or when there is no appreciable improvement in CT appearances with medical treatment.

Antitubercular Agents↗