Control method for hyperthermia treatment apparatus using ultrasound
AssigneeTechnomed Medical Systems
InventorJacques Dory
Life of this patent
Estimating the term…
Abstract
A method for controlling an ultrasonic hyperthermia treatment apparatus is disclosed. The hyperthermia treatment apparatus utilizes ultrasound that is focused at a focal spot. The position of the focal spot relative to the transducer is varied, where the peak power of the focal spot and the degree of overlap between the various positions of the focal spot are such that the energy radiated during a shot at each point in the region scanned by the variation of the position of the focal spot represents an equivalent focal spot where the energy applied to the object to be treated is substantially equal to the energy needed to destroy the cell tissue.
Claims20
A method for controlling an ultrasonic hyperthermia treatment apparatus having a transducer with a plurality of piezoelectric elements, each element excited by an electrical signal, the method comprising the steps of:
- a) emitting ultrasound focused at a focal spot;
- b) varying a position of said focal spot during a shot, with respect to said transducer to cause a region to be treated to be scanned by the focal spot such that a plurality of positions of the focal spot defines an equivalent focal spot;
- c) the speed of variation of the position of said focal spot with respect to said transducer is higher than the speed of diffusion of thermal energy in the region to be treated;
- and
- d) the peak power of the focal spot and the degree of overlap between the plurality of positions of said focal spots are arranged such that, during the shot, the energy radiated at every point in the region scanned by varying the position of said focal spot with respect to said transducer is substantially equal to the energy needed to destroy tissue cells in the region to be treated.
A method for controlling an ultrasonic hyperthermia treatment apparatus having a transducer with a plurality of piezoelectric elements, each element excited by an electrical signal, the method comprising the steps of:
- a) emitting ultrasound focused at a focal spot;
- b) varying a position of said focal spot during a shot, with respect to said transducer to cause a region to be treated to be scanned by the focal spot such that a plurality of positions of the focal spot defines an equivalent focal spot;
- c) the speed of variation of the position of said focal spot with respect to said transducer is higher than the speed of diffusion of thermal energy in the region to be treated;
- d) the variation of the position of said focal spot with respect to said transducer solely due to variation in relative phases of the electrical signals exciting said piezoelectric elements;
- and
- e) the peak power of the focal spot and the degree of overlap between the plurality of positions of said focal spot are such that, during the shot, the energy radiated at every point in the region scanned by varying the position of said focal spot with respect to said transducer is substantially equal to the energy needed to destroy tissue cells in the region to be treated.
A hyperthermia treatment apparatus comprising:
- a) a transducer with a plurality of piezoelectric elements, each element excited by an electrical excitation signal, the transducer having a focus spot;
- b) a transmitter for generating each said electrical excitation signal;
- c) each said transmitter receiving an identical high-frequency pilot signal from a common source, and each said transmitter receiving an address from an address generator;
- d) each said transmitter further including means for shifting the phase of said received high-frequency pilot signal as a function of an address received from the address generator to provide the electrical excitation signal to the piezoelectric elements;
- and
- e) said means for shifting the phase configured to cause the position of the focus spot to vary, and configured to cause a degree of overlap between the focus spots to vary such that a speed of variation of the position of said focal spots is higher than the speed of diffusion of thermal energy in the region to be treated.
Dependencies are inferred from the claim text.