Stationary Headband for Clinical Time‐of‐Flight Optical Imaging at the Bedside

Abstract

Conventional brain-imaging modalities may be limited by high cost, difficulty of bedside use, noncontinuous operation, invasiveness or an inability to obtain measurements of tissue function, such as oxygenation during stroke. Our goal was to develop a bedside clinical device able to generate continuous, noninvasive, tomographic images of the brain using low-power nonionizing optical radiation. We modified an existing stage-based time-of-flight optical tomography system to allow imaging of patients under clinical conditions. First, a stationary head-band consisting of thin, flexible optical fibers was constructed. The headband was then calibrated and tested, including an assessment of fiber lengths, the existing system software was modified to collect headband data and to perform simultaneous collection of data and image reconstruction, and the existing hardware was modified to scan optically using this headband. The headband was tested on resin models and allowed for the generation of tomographic images in vitro; the headband was tested on critically ill infants and allowed for optical tomographic images of the neonatal brain to be obtained in vivo.

On-line optical imaging of the human brain with 160-ms temporal resolution

“…Most of the devices for optical brain imaging feature relatively long acquisition times. In fact, reported acquisition times per image are 3-5 s [5,13], < 30 s [14], 2.5 min [15], several hours [16,17], 1-3 days [18], and not-quantified "slow data acquisition rate" [19], and "long measurement times" [20]. While these acquisition times can be appropriate for structural imaging or for the monitoring of slow dynamic processes, it is desirable to exploit the capability of high temporal resolution afforded by optical methods in functional brain imaging.…”

Non-invasive optical mapping of the piglet brain in real time

“…The novelty of our approach is the fast acquisition time of the optical maps, namely 192 ms, which allowed us to produce a real-time video of the temporal evolution of the subcortical hemorrhage. Other groups have reported longer acquisition times in non-invasive optical brain imaging of 5 s [11], <30 s [12], 2.5 min [13], several hours [14,15], 1-3 days [16], and not-betterquantified "slow data acquisition rate" [17] and "long measurement times" [18]. Our fast acquisition rate provides a tool to investigate the spatial distribution of the arterial pulsation, which may result in a practical approach to assessing tissue viability in human subjects.…”

Estimation and Measurement of Biological Tissues Using Optical Simulation Method

“…Early detection of tumors in the human breast and other biological tissues by optical tomography [3,4] have been carried out. The optical properties like absorption coefficient (µa), scattering coefficient (µs) and anisotropy parameter (g) are determined by various procedures [5,6]. An important application of lasers in medicine warrants thorough understanding and knowledge about complex photon tissue interaction mechanisms.…”