Ultrasonic surgical instrument, associated surgical method and related manufacturing method
An ultrasonic therapeutic apparatus includes a handle, a horn or concentrator section terminating in an operative tip, and a transducer assembly set disposed in the handle and operatively engaged with the horn or concentrator section for generating ultrasonic mechanical vibrations therein to vibrate the operative tip during contact thereof with target tissue at a surgical site in a patient. An electrical waveform generator is operatively connected to the transducer assembly for energizing the transducer assembly set with one or more predetermined time reversal ultrasonic waveforms that, upon being applied to the transducer assembly set, result in respective predetermined patterns of motion of the operative tip.
1. A method for manufacturing a medical instrument, comprising:
fabricating an ultrasonic horn or concentrator having a predetermined shape and size;
operatively connecting an upstream or input portion of said horn or concentrator to an ultrasonic transducer assembly;
energizing said transducer assembly to generate at an input or upstream end of said horn or concentrator an ultrasonic calibration vibration having a desired motion pattern and desired frequency and amplitude characteristics;
automatically tracking movement of an operative tip of said horn or concentrator upon generation of said calibration vibration at said input or upstream end of said horn or concentrator;
automatically recording at least one signal encoding the tracked movement;
processing the recorded signal to generate a time reversal waveform; and
storing said time reversal waveform in a storage medium.
2. The method defined in claim 1 wherein said horn or concentrator is a test or calibration device, said transducer assembly being a test or calibration assembly, further comprising packaging said storage medium with an ultrasonic medical instrument including a handle, a horn or concentrator section identical to said test or calibration device and terminating in an operative tip identical to the operative tip of said test or calibration device, a transducer arrangement identical to said test or calibration assembly and disposed in said handle and operatively engaged with said horn or concentrator section for generating ultrasonic mechanical vibrations therein to vibrate said operative tip during contact thereof with target tissue at a surgical site in a patient, and an electrical waveform generator operatively connected to said transducer arrangement for energizing same with an electrical waveform, said waveform generator including said storage medium storing said time reversal waveform.
3. The method defined in claim 1 , further comprising packaging said storage medium with an ultrasonic medical instrument including a handle, said horn or concentrator being connected to said handle, said transducer assembly being disposed in said handle and operatively engaged with said horn or concentrator for generating ultrasonic mechanical vibrations therein to vibrate said operative tip during contact thereof with target tissue at a surgical site in a patient, said instrument further including an electrical waveform generator operatively connectable to said transducer assembly for energizing same with an electrical waveform, said waveform generator including said storage medium storing said time reversal waveform.
4. The method defined in claim 1 wherein said ultrasonic calibration vibration is a short pulse, said movement of said tip being a long reverberation signal.
5. The method defined in claim 1 wherein the processing of said recorded signal includes time reversing said recorded signal and normalizing the time-reversed signal.
6. The method defined in claim 1 wherein said transducer assembly is so configured relative to said horn or concentrator to produce, in a proximal end portion of said horn or concentrator, ultrasonic vibrations having a transverse or shear component, said ultrasonic calibration vibration having a transverse or shear component.
7. The method defined in claim 1 wherein said shape of said horn or concentrator is asymmetric about a longitudinal axis of said upstream or input portion of said horn or concentrator.
8. The method defined in claim 1 wherein tracking the movement of said operative tip of said horn or concentrator includes operating at least one laser vibrometer.