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Alexander Graham Bell's "other telephone" may soon be used in brain imaging

In 1880 Bell demonstrated a successful transmission of an audio conversation on a beam of light. It was the first wireless phone! But because light has a hard time travelling through many objects instead of bouncing off them, his other phone became the standard.

But now the phenomenon named the photoacoustic effect is making a comeback in medical imaging, including brain imaging.

As a recent article in The Economist puts it:

"To create a photoacoustic image, pulses of laser light are shone onto the tissue being scanned. This heats the tissue by a tiny amount—just a few thousandths of a degree—that is perfectly safe, but is enough to cause the cells to expand and contract in response. As they do so, they emit sound waves in the ultrasonic range. An array of sensors placed on the skin picks up these waves, and a computer then uses a process of triangulation to turn the ultrasonic signals into a two- or three-dimensional image of what lies beneath."

Working at tissue depths of up to 7 cm, the device would be hand-held, literally putting brain scan technology into the clinic and doctor's office.

There is a problem with the transmission of sound through the skull, but if we place the sensor on the neck, or near the eye, the bone problem could be resolved because at those places there is a direct connection with the brain without the bone barrier.

You may soon be using a photoacoustic brain imagin device that looks similar to this soft tissue laser therapy wand:

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