Abstract: The invention relates to an apparatus for high energetic ultrasound tissue shrinkage in a target area inside a living body from an outside surface or a body cavity of the living body. The apparatus comprises an ultrasound generator, a device to the applied against the skin or mucous membrane at the site of treatment, and a transducer connected with the ultrasound generator to emit generated therapeutic ultrasound energy through said device. Means are provided for cooling a contact surface of the device to be engaged with the skin or mucous membrane, and the device is made as an exchangeable product forming a heat exchange element between the device and the tissue.

Abstract: A method and an apparatus for generating short ultrasonic echo pulses by means of an ultrasonic transducer (2) utilizes a shift register (6) for storing a signal for excitation of said ultrasonic transducer. The stored signal is a weighted least squares filter signal to the transducer proper and is supplied to said transducer via a digital-to-analogue converter (7). Repeated adjustment of the stored signal can be effected by supplying, via an analogue-to-digital converter (11), the echo pulse signals from the ultrasonic transducer to a logic unit (12) for analysis.

Abstract: An apparatus for determining the depth position of venous thrombi in the lower extremities utilizes a unique property in .sup.125 I. This resides in the fact that in approximately half of all disintegrations, two photons are emitted simultaneously. These two coincident photons have, like separately emitted photons, an energy of approximately 28 keV. A scintillation detector perceives the coincidently emitted photons as one photon of an energy of 56 keV. The quotient between the number of separately emitted photons and the number of coincident photons may thus be determined. This quotient constitutes a parameter which is greatly dependent on the distance between the detector and the source of radiation, whereby there is obtained a possibility of determining the depth of the thrombus.