Laser speckle is an interference phenomena which is always present when a laser is used. Time-average speckle interferograms of the left and right side of the chest of a normal healthy subject were recorded at the Fourier transform plane on a fine grain photographic plate, while the subject held his breath. The interferogram was analysed by the point wise method and a graph was drawn between the position and the displacements at corresponding points on the chest wall* The associated displacements of the chest wall due to heart action are correlated with cardiac function. © 1980 SPIE. All rights reserved.

A. Periasamy

B. M. Sivaram

Interferometry

CARDIAC FUNCTIONS

CARDIAC MONITORING

Healthy subjects

INTERFERENCE PHENOMENA

Interferograms

LASER SPECKLE

SPECKLE INTERFEROGRAMS

TIME AVERAGES

Speckle

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Cardiac Monitoring Using Laser Speckle

Proceedings of SPIE - The International Society for Optical Engineering

Time-average speckle interferometry has been applied to obtain displacement patterns on the chest wall produced by cardiac action, in the absence of breathing, during various phases of the cardiac cycle. This has been achieved by an electronic shutter, controlled by the electrocardiogram of the subject. The recorded holographic plates processed under identical conditions are scanned by the pointwise method to obtain the absolute displacements at various locations corresponding to the activities of the various cardiac chambers and values. These data are transformed to a 40 × 30 matrix by an interpolation method and, from this, three-dimensional displacement plots are reconstructed by an IBM PC/AT computer. These patterns shown the displacements over the entire cardiac area corresponding to the activities of various regions during the cardiac cycle. The apex and aortic valve areas show the maximum displacements during the systolic phase. During the diastolic phase the activities over the low pressure atrial regions are also observed. The results obtained outline the functional details of the normal heart and the activities over various areas are in agreement with that of other noncontact techniques. © 1991 IEEE

IEEE Transactions on Biomedical Engineering

Reconstruction of Sequential Cardiac In-Plane Displacement Patterns on the Chest Wall by Laser Speckle Interferometry

Medical & Biological Engineering & Computing

Imaging of chest motion due to heart action by means of holographic interferometry

Journal	Data powered by TypesetProceedings of SPIE - The International Society for Optical Engineering
Publisher	Data powered by TypesetSPIE
ISSN	0277786X
Open Access	No