Articular cartilage is a hyaline cartilage that lines the subchondral bone in the diarthrodial joints. Near infrared NIR spectroscopy is emerging as a nondestructive modality for the evaluation of cartilage pathology; however, studies regarding the depth of penetration of NIR radiation into cartilage are lacking. The average thickness of human cartilage is about 1—3 mm, and it becomes even thinner as OA progresses.
Near-infrared NIR spectroscopy is one of the most popular non-destructive detection methods. However, it is challenging to collect spectra exactly due to the multiple scattering and absorbing by the skin and internal tissues. For this purpose, the diffused transmission spectra were collected with removing the sample slices along the perpendicular bisector of the source-detector line.
As with all EMR, IR carries radiant energy and behaves both like a wave and like its quantum particle, the photon. Infrared radiation was discovered in by astronomer Sir William Herschelwho discovered a type of invisible radiation in the spectrum lower in energy than red light, by means of its effect on a thermometer. The balance between absorbed and emitted infrared radiation has a critical effect on Earth's climate. Infrared radiation is emitted or absorbed by molecules when they change their rotational-vibrational movements.
Traumatic brain injury TBI is a growing health concern effecting civilians and military personnel. Research has yielded a better understanding of the pathophysiology of TBI, but effective treatments have not been forthcoming. Yet, it remains unclear if sufficient photonic energy can be delivered to the human brain to yield a beneficial effect.
E-mail address: jbli Email: jbli Use the link below to share a full-text version of this article with your friends and colleagues.
Low level light therapy has garnered significant interest within the past decade. The exact molecular mechanisms of how red and near infrared light result in physiologic modulation are not fully understood. Heme moieties and copper within cells are red and near infrared light photoreceptors that induce the mitochondrial respiratory chain component cytochrome C oxidase, resulting in a cascade linked to cytoprotection and cellular metabolism.
Lasers in Medical Science. Penetration depth of ultraviolet, visible light and infrared radiation in biological tissue has not previously been adequately measured. Risk assessment of typical intense pulsed light and laser intensities, spectral characteristics and the subsequent chemical, physiological and psychological effects of such outputs on vital organs as consequence of inappropriate output use are examined. This technical note focuses on wavelength, illumination geometry and skin tone and their effect on the energy density fluence distribution within tissue.
The outermost layer the surface is called the stratum corneum, while the deepest part is called the dermis. The dermis is rich in blood vessels where the blood circulating regulates body temperature, has a dense network of nerve endings and corpuscles which serve to perceive tactile stimuli, heat and pain. The stratum corneum is the largest surface body, perception and the resulting infrared heat presuppose a penetration and absorption of radiation in the skin.
Published this week in the Neuropsychiatric Disease and Treatment, the study "Near-infrared photonic energy penetration: can infrared phototherapy effectively reach the human brain? The findings include:. Previous work by Henderson and others has shown that the most common areas injured in the human brain are the bottom of the frontal lobes and the temporal lobes which can be cm from the scalp.