A. Y. Bluestone

Learn More
We report on the first three-dimensional, volumetric, tomographic localization of vascular reactivity in the brain. To this end we developed a model-based iterative image reconstruction scheme that employs adjoint differentiation methods to minimize the difference between measured and predicted data. The necessary human-head geometry and optode locations(More)
Diffuse optical tomography (DOT) is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR) light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently,(More)
Instrumentation is described that is suitable for acquiring multisource, multidetector, time-series optical data at high sampling rates (up to 150 Hz) from tissues having arbitrary geometries. The design rationale, calibration protocol, and measured performance features are given for both a currently used, CCD-camera-based instrument and a new(More)
In this study, we explore the potential of diffuse optical tomography for brain oximetry. While several groups have already reported on the sensitivity of optical measurements to changes in oxyhemoglobin, deoxyhemoglobin, and blood volume, these studies were often limited to single source-detector geometries or topographic maps, where signals obtained from(More)
This is the second part of a two-part study that explores the feasibility of 3-D, volumetric brain imaging in small animals by optical tomographic techniques. In part 1, we demonstrated the ability to visualize global hemodynamic changes in the rat head in response to elevated levels of CO(2) using a continuous-wave instrument and model-based iterative(More)
We performed threedimensional optical tomographic brain imaging studies on small animals. Using nearinfrared continuous light to probe rat brains, we were able to test our diffuse optical tomographic reconstruction algorithm. The preliminary experimental results focused on visualizing the hemodynamics in the rat head in response to perturbations in the(More)
In recent years near-infrared optical tomographic imaging (OTI) has made big strides towards becoming a clinically relevant medical imaging modality. Imaging of dynamic changes in blood parameters, functional brain imaging, and breast imaging are the most advanced areas of application of this novel technique. In this study we focus on difficulties that are(More)
We have developed a system for acquiring three-dimensional dynamic images of small tissue volumes. As a first example we explored the real-time response of changes in optical properties inside a human finger caused by partial occlusion of distal veins. 2002 Optical Society of America OCIS codes: (170.0170) Medical optics and biotechnology, (110.0110)(More)