Hand-held based near-infrared optical imaging devices: A review
ABSTRACT Near-infrared (NIR) optical imaging is a non-invasive and non-ionizing modality that is emerging as a diagnostic/prognostic tool for breast cancer and other applications related to functional brain mapping. In recent years, hand-held based optical imaging devices are developed for clinical translation of the technology, as opposed to the various bulky optical imagers available. Herein, we review the different hand-held based NIR devices developed to date, in terms of the measurement techniques implemented (continuous wave, time or frequency-domain), the imaging methods used, and the specific applications towards which they were applied. The advantages and disadvantages of the different hand-held optical devices are described and also compared with respect to a novel hand-held based device currently developed in our Optical Imaging Laboratory towards three-dimensional tomography studies.
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- "2.2 Hemodynamic Response by NIRS Optical brain imaging exploit unique property of light to image the brain for clinical as well basic science related applications. Near Infrared (IR) light (wavelength 600 -1000 nm) easily penetrates the biological tissue (S. Erickson et al, 2009, M. Tamura et al, 1997). Figure 1 shows absorption spectra of HHB and HbO 2 . "
ABSTRACT: To understand Working of Human Brain measurements related to the brain function are required. These measurements should be possibly non-invasive. Brain should be disturbed as less as possible during the measurement. Integration of various modalities plays a vital role in understanding the cognitive and the behavioral changes in the human brain. It is an important source of converging evidence about specific aspects of neural functions and dysfunctions under certain pathological conditions. Focal changes in cortical blood flow are tightly coupled with the changes in neuronal activity. This constitutes the option to map the hemodynamic response and infer principles of the cortical processing, even of complex tasks. The very high temporal resolution of EEG and good spatial resolution by NIRS make this concurrent measurement unique to study the spatio-temporal dynamics of large scale neuronal networks in the human brain. Such integration of two techniques will help to overcome the limitations of a specific method. Such as insensitivity of electroencephalogram (EEG) to unsynchronized neural events or lack of near infrared spectroscopy (NIRS) to low metabolic demand. A combination of EEG and NIRS will be more informative than the two separate analyses in both modalities.International Journal of Computer Applications 07/2013; 63(5). DOI:10.5120/10464-5175 · 0.82 Impact Factor
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ABSTRACT: We designed a new aortic root prosthesis, using the existing dacron tube graft material, which has compliant sinuses similar to those in the natural aortic root. The prosthesis was used to replace the aorta and the sinuses in the valve sparing operation in 4 human and 7 porcine aortic roots. The dynamics of the aortic graft root and the leaflets were studied in a left heart simulator. Both, the movement of the leaflets and of the commissures during a cardiac cycle was similar to that in the natural aortic root. Hence, the new prosthesis offers the most natural conditions to the functioning aortic leaflets and thus is expected to enhance longevity of the leaflets in the valve sparing operationBMES/EMBS Conference, 1999. Proceedings of the First Joint; 02/1999
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ABSTRACT: Optical photographic imaging is a well known imaging method that has been successfully translated into biomedical applications such as microscopy and endoscopy. Although several advanced medical imaging modalities are used today to acquire anatomical, physiological, metabolic, and functional information from the human body, optical imaging modalities including optical coherence tomography, confocal microscopy, multiphoton microscopy, multispectral endoscopy, and diffuse reflectance imaging have recently emerged with significant potential for non-invasive, portable, and cost-effective imaging for biomedical applications spanning tissue, cellular, and molecular levels. This paper reviews methods for modeling the propagation of light photons in a biological medium, as well as optical imaging from organ to cellular levels using visible and near-infrared wavelengths for biomedical and clinical applications.IEEE Reviews in Biomedical Engineering 02/2010; 3(3):69 - 92. DOI:10.1109/RBME.2010.2081975