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Biomedical subjects

S N Tandon

Publications and source records attributed to S N Tandon.

At least 19 recordsLinked to original sources
PubMed1995

Texture analysis of CT-images for early detection of liver malignancy.

In certain medical images e.g., ultrasound it has been seen that the texture conveys useful diagnostic information but in CT and MR images its proper use has not been established. Present study is an attempt to investigate the use of texture analysis for early detection of liver malignancy when the onset of disease is beyond human perception, using CT-images. Using grey level run length as a primitive, five parameters viz., Short Run Emphasis (SRE), Long Run Emphasis (LRE), Grey Level Distribution (GLD), Run Length Distribution (RLD) and Run Percentage (RP) have been studied for this purpose. It has been found that the GLD feature, obtained using Grey Level Run Length Method (GLRLM) conveys useful information about the onset of this disease with a confidence level of above 99 percent. The results have been confirmed on the basis of clinical studies.

Humans↗
PubMed1995

DSP based enhanced data acquisition system.

Digital Signal Processing (DSP) based Enhanced Data Acquisition System for Electrocardiography/Verctorcardiography (ECG/VCG) has been developed. The system is based on Texas Instrument's TMS320C25 Digital Signal Processor which has the capability of executing 5 Million Instructions Per Second (MIPS) at peak speed. This processor provides the necessary requirements of parallel processing, instruction pipelining, execution of multiple instructions in a single clock cycle for real time data acquisition and analysis of Bio Signals. The present work describes the enhanced data acquisition system using DSP chip along with its peripherals.

Biomedical Engineering↗
PubMed1994

Identification of substructures in CT-images.

Identification of substructures is one of the important issues in automated and computer assisted systems used for interpretation of radiographic images because of vague definition of organ shape. In this paper an Autoregressive model has been proposed for shape description of substructures(organs) obtained in the form of outer boundaries from the abdominal CT-images. The results of matching show the effectiveness of the proposed model in identifying substructures from the images.

Humans↗
PubMed1992

An 8086-based Holter arrhythmia monitor.

Holter monitoring is a technique which involves the use of a specialized recorder to record and analyze the ECG of an ambulatory subject for a duration up to 24 h. It is used for persons who have generally normal ECG, but who experience heart disorders under some particular stress conditions. This paper describes the design of an 8086-based Holter monitor using state-of-the-art technology. The old concept of analog signal processing and cassette recording has been replaced by digital signal processing and solid state memories. The main features of the new monitor, as compared with conventional ones, is its intelligence to detect and record arrhythmias which are of clinical importance. Emphasis was placed on miniaturization and minimization of the power consumption while designing the monitor.

Algorithms↗
PubMed1980

A versatile SAMI--a self contained digital heart beat counter.

The existing SAMI's (Socially acceptable monitoring instruments) as used for monitoring the variations in physiological parameters were considered to have certain drawbacks, such as trigger level adjustments and the need for frequent contact with the clinician/investigator. In the present system these drawbacks have been overcome by incorporating an automatic gain control into the circuitry and by using CMOS devices.

Computers↗
PubMed1980

Optimization of carrier frequency and duty cycle for pulse modulation of biological signals.

Digital modulation techniques are commonly used for the recording and transmission of biological signals. Hitherto, the choice of subcarrier frequency for recording or transmission of biological signals has been arbitary and this usually results in poor signal to noise ratio (SNR) due to the limited frequency characteristics of the system. In the present study the frequency characteristics of the system (first order approximation) has been taken to be that of a Butterworth filter. Computations based on this assumption show that for a given input signal there exists an optimum subcarrier frequency and a corresponding optimum duty cycle which would give maximum SNR of the system. For convenience, a nomogram has been prepared and it has been shown that for a given frequency response of the system, the nomogram could be used for selecting an optimum subcarrier frequency and a corresponding duty cycle. The theoretical formulations have been verified with experimental work.

Biomedical Engineering↗
PubMed1976

Bacterial contamination of skin used as a biological dressing. A potential hazard.

Bacterially contaminated skin used as a biological dressing on burn wounds can cause serious or even lethal infections, three examples of which are cited. Cadaver-skin allografts were frequently found to contain pathogenic bacteria. The frequency of infections due to the use of contaminated skin grafts on open wounds is unknown.

Autopsy↗
PubMed1976

Cerium nitrate: a new topical antiseptic for extensive burns.

The wounds of 60 burned patients were treated topically with cerium nitrate, which was applied either as a cream or in aqueous solution. Cerium nitrate has a potent antiseptic effect in human burn wounds, especially against gram negative bacteria and fungi. Pseudomonas aeruginosa was recovered from the wounds infrequently and never predominated. Fungi were practically never found. No patient treated with cerium developed a necrotizing wound infection. Analysis of the detailed bacteriological data indicated that, in contrast to previous results with use of the nitrate or sulfadiazine salts of silver, when gram negative species predominated, the flora tended to be predominantly gram positive when cerium was used. Therefore, some patients were treated simultaneously with cerium nitrate and silver sulfadiazine; this resulted in an even more efficient suppression of the wound flora than was observed previously with either cerium alone or silver salts alone; results with the simultaneous topical therapy in patients with injuries that previously were uniformly lethal were excellent. No toxicity attributable to the use of cerium was observed, although one instance of methemoglobinemia due to nitrate was documented. The adsorption of topically applied cerium essentially is nil. The use of cerium nitrate was associated with a nearly 50 percent reduction in the anticipated death rate. Cerium nitrate is a promising new topical antiseptic agent for the treatment of burns, particularly when it is used in combination with silver sulfadiazine.

Adolescent↗