Optical coherence tomography imaging of cardiac trabeculae

Abstract

An integrated instrument is being developed to study live cardiac trabeculae, which is capable of stimulating the muscle under controlled conditions while measuring the heat production, force, and sarcomere length distribution. To improve the accuracy of estimation of stress, strain, and volumetric heat production, the geometry of the muscle must be known. A spectral domain optical coherence tomography system (SD-OCT) has been constructed and calibrated to image the trabecula mounted inside the instrument. This system was mounted above the muscle chamber and a series of equally-spaced cross-sectional images were obtained. These were processed using a workflow developed to extract cross-sectional area and volume. The initial results have demonstrated the feasibility of using OCT to capture the overall geometry of cardiac trabecula mounted in the instrument. Further work will be directed to improve the image quality for larger samples and apply meshing algorithms to the acquired data.

Four-Dimensional Imaging of Cardiac Trabeculae Contracting In Vitro Using Gated OCT

“…A spectral domain OCT was built in-house to perform a volumetric scan of a cardiac trabecula [16], [18]. A superluminescent diode with a center wavelength of 840 nm and a spectral width of 90 nm (Broadlighter D-840, Superlum) provided the light source.…”

“…Depth resolution was calibrated using a reference glass slide, and was found to be 3.17 μm per pixel. The galvanometer displacement was calibrated using a negative 1951 USAF resolution test target [16].…”

“…The principles of this imaging technique can also be applied to the estimation the elastic properties of soft tissues [15]. We have previously demonstrated the use of OCT in imaging chemically-fixed trabecula samples mounted in a fluid bath, at a resolution of 3.6 µm  23 µm  23 µm (D  L  W) [16].…”

Computational Modelling of Cardiac Trabecula Mechanics

“…The Auckland Bioengineering Institute (abi) has previously developed a novel cardiac myometer which is capable of measuring muscle force and displacement (among other measurements) of a trabecula undergoing fixed-length contractions [5]. More recently, an optical coherence tomography (oct) system was incorporated into the cardiac myometer for measuring the geometric shape changes of cardiac trabeculae in vitro during a contraction [4].…”