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What is the power of laser light used in Laser Doppler Blood flowmeter?

What is the power of laser light used in Laser Doppler Blood flowmeter? Correct Answer 5 mW

In principle, light from a low power (5 mW) He–Ne laser is coupled into a quartz fibre and transmitted to the skin. The light is reflected from both the non-moving tissues (reference beam) and moving red blood cells (Doppler-shifted beam). The two beams are received by a plastic fibre and transmitted back to a photo-diode where optical heterodyning takes place.

Related Questions

Consider the following statements about the Open and Closed Blood Circulatory System:   A) Open blood circulatory system does not contain special blood vessels to carry oxygenated and deoxygenated blood, while in the closed blood circulatory system blood vessels are present. B) Oxygenated and Deoxygenated blood gets mixed in the closed blood circulatory system, while oxygenated and deoxygenated blood does not get mixed in the open blood circulatory system. Choose the correct statement.
Which laser is used in Laser doppler blood flowmeter?
In the question two statements are given, followed by two conclusions, I and II. Read all the conclusions and then decide which of the given conclusions logically follow/s from the given statements. Statements: All white blood cells are red blood cells. Some blood cells are red blood cells. Conclusions: I. All blood cells are red blood cells, is a possibility. II. Some red blood cells are not blood cells.
Where optical heterodyning takes place in Laser Doppler Blood Flowmeter?
The moon looks blood red during a total lunar eclipse because some of the sunlight passes through Earth’s atmosphere to reach the moon. As the white light breaks up while passing through the atmosphere, most of its blue-colored wavelengths are absorbed and scattered. The remaining red wavelengths light up the moon in blood-red color. Which of the following statements do not support the assertion of the above-given statement? I: The moon looks blood red during a total lunar eclipse as the white light breaks up due to the Earth's atmosphere where most of its red-colored wavelengths are absorbed. II: The moon looks blood red during a total lunar eclipse as the earth blocks the white light to travel to the moon.
Under the ABO method, a person with an unknown blood group loses a lot of blood in a road accident and needs an immediate blood transfusion. A friend of his, who has a valid certificate of his blood group, requests for blood donation without any delay. The blood group of the blood donor is:
In a blood donation camp, 100 people donated blood. 37 of them had blood group ’A’, 31 had blood group ‘B’, 14 had blood group ‘O’ and rest had blood group ‘AB’. If a sample is chosen at random, what is the probability that the sample contains blood of group ‘AB’?
Read the following passage carefully and choose the most appropriate answer to the question out of the four alternatives.
The human eye is a complex part of the body that is used for seeing. Eyes enable people to perform daily tasks and to learn about the world that surrounds them. Sight, or vision, is a rapidly occurring process that involves continuous interaction between the eye, the nervous system, and the brain. When someone looks at an object, what he really sees is the light reflected from the object. This reflected light passes through the lens and falls on the retina of the eye. Here the light induces nerve impulses that travel through the optic nerve to the brain and then over other nerves to muscles and glands.
The eye is similar to a television camera. Both the eye and the television camera convert light energy to electrical energy. The eye converts light to nerve impulses that are interpreted by the brain as the sense perception called sight. A television camera converts light to electronic signals that are broadcast and transformed into light images in a television receiver. It is wonderful that human eyes blink an average of once every six seconds. This washes the eye with the salty secretion from the tear or lachrymal glands. Each tear gland is about the size and shape of an almond. These glands are situated behind the upper eyelid at the outer corner of the eye. After passing over the eye, the liquid from the gland is drained into the nose through the tear duct at the inner corner of the eye. The sense perception that the brain releases after the eye converts light to nerve impulses is known as
A patient of hemorrhagic shock requires Blood transfusion. His blood group is B+ve. Blood bank informed that following blood group blood is available. Which blood can be used?
Read the following passage carefully and choose the most appropriate answer to the question out of the four alternatives.
The human eye is a complex part of the body that is used for seeing. Eyes enable people to perform daily tasks and to learn about the world that surrounds them. Sight, or vision, is a rapidly occurring process that involves continuous interaction between the eye, the nervous system, and the brain. When someone looks at an object, what he really sees is the light reflected from the object. This reflected light passes through the lens and falls on the retina of the eye. Here the light induces nerve impulses that travel through the optic nerve to the brain and then over other nerves to muscles and glands.
The eye is similar to a television camera. Both the eye and the television camera convert light energy to electrical energy. The eye converts light to nerve impulses that are interpreted by the brain as the sense perception called sight. A television camera converts light to electronic signals that are broadcast and transformed into light images in a television receiver. It is wonderful that human eyes blink an average of once every six seconds. This washes the eye with the salty secretion from the tear or lachrymal glands. Each tear gland is about the size and shape of an almond. These glands are situated behind the upper eyelid at the outer corner of the eye. After passing over the eye, the liquid from the gland is drained into the nose through the tear duct at the inner corner of the eye. What do we see when we look at an object?