Optoacoustic imaging (Photoacoustic Imaging) is an imaging technology based on the photoacoustic effect, and can be used for obtaining images of structures in turbid environments. The optoacoustic technique combines the accuracy of spectroscopy with the depth resolution of ultrasound.
The oldest technical application of the photothermal effect is believed to be the photophone, a communication device invented by Bell (1880). Bell observed the emanation of audible sounds from a transparent tube containing material in suspension, when a modulated light source is focused on the tube. Modulation of the light impinging on an absorbing substance will produce a similar modulation in temperature via the photothermal effect.
Optoacoustic wave generation
When a short laser pulse irradiates an absorbing medium there is local absorption →local heating → local expansion. This local expansion leads to ultrasonic pressure waves that travel through the medium at the speed of sound, and can be recorded using high frequency pressure sensors (such as piezoelectric sensors or optical sensors). The slow speed of sound in tissue (~1500 m/s) in comparison to the speed of light allows for the time resolved detection of these pressure waves and the determination of depth from where these pressure waves originated. By using an array of sensors the temporal delay of these incoming pressure wavefronts can be combined into an ultrasound image.
Although the technology is still in its infancy, optoacoustic imaging is being employed in the development of various devices. Such devices include breast cancer detection equipment, as well as equipment used for measuring blood oxygenation levels. In both cases, the change in the optical properties of blood in respect to oxygen saturation and the strong optical contrast between hemoglobin and surrounding tissue is utilized.
Affects one in three adults
Affecting about 35 percent of all adults in the United States according to the CDC, metabolic syndrome contributes to weight gain, by causing a state of internal starvation called metabolic starvation. This in turn leads to increases hunger, sugar cravings and increased portions leading to overeating and weight gain.
Cause and effect misunderstood
Since we traditionally thought that the portion control (which in turn was attributed wrongly to poor will power)is the cause of weight gain, rather than the effect of this metabolic starvation, all our traditional ideas about cause and effect of obesity were not only wrong but lead to the “blame the victim” attitude when it comes to obesity.
Secret of weight gain revealed
Secret of weight gain, and metabolic syndrome revealed - it has been recently proven that metabolic syndrome, and the weight gain itself are caused by a process called insulin resistance. Check your metabolic syndrome risk using the free Metabolic syndrome meter. Watch this amazing Ted Med video that reveals the secret of weight loss - Stop blaming the victim for obesity