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No effect was detected on listeners in the study when only the ultrasonic [14] (frequencies higher than 24 kHz) portion of the test material was played for test subjects; the demonstrated effect was only present when comparing full-bandwidth to bandwidth-limited material.
Medical device cannot be classified as a class I device because the controls authorized are insufficient to provide reasonable assurance of the safety and effectiveness of the device. Medical device has sufficient information to establish a performance standard and it is necessary to establish a performance standard for the device.
Ultrasound is sound with frequencies greater than 20 kilohertz. [1] This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz.
Medical ultrasound includes diagnostic techniques (mainly imaging techniques) using ultrasound, as well as therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal body structures such as tendons, muscles, joints, blood vessels, and internal organs, to measure some characteristics (e.g., distances and velocities) or to generate an informative audible sound.
In Canada, various federal acts govern non-ionizing radiation by originating source, such as the Radiation Emitting Devices Act, the Canada Consumer Product Safety Act, and the Radiocommunication Act. [56] For situations not under federal jurisdiction, Canadian provinces individually set regulations around use of non-ionizing radiation. [57]
A curvilinear array ultrasonic transducer for use in medical ultrasonography Inside construction of a Philips C5-2 128 element curved array ultrasound sensor. Ultrasonic transducers and ultrasonic sensors are devices that generate or sense ultrasound energy. They can be divided into three broad categories: transmitters, receivers and transceivers.
Extracorporeal shockwave therapy involves focused, high-energy ultrasound pulses that can be used to break solid masses into fragments. [10] This is often utilized to break up calculi such as kidney stones and gallstones into pieces small enough to be passed from the body without undue difficulty, a procedure known as lithotripsy. The success ...
Photoacoustic imaging or optoacoustic imaging is a biomedical imaging modality based on the photoacoustic effect.Non-ionizing laser pulses are delivered into biological tissues and part of the energy will be absorbed and converted into heat, leading to transient thermoelastic expansion and thus wideband (i.e. MHz) ultrasonic emission.