Apparatus and method for inducing vibrations in a living body

Abstract

A medical device incorporating magnetic material is introduced into the body of a patient. A time varying magnetic field is generated externally of the patient's body and which is of sufficient strength to magnetically induce motion in the device, thereby causing the medical device to vibrate within the patient's body. The frequency and the amplitude of the magnetic field oscillations can be continuously varied to control the vibrations induced in the medical device.

What is claimed is:  
     
         1 . A method for generating vibrations in a magnetic object disposed within a living body, comprising the steps of: 
 disposing the object within the body; and    disposing adjacent to the body at least one pulsating magnetic source with no physical connection to the object to generate an oscillating magnetic field to magnetically induce motion in the object.    
     
     
         2 . The method of  claim 1 , wherein the object comprises magnetic material selected from the group consisting of ferromagnetic and ferrimagnetic materials.  
     
     
         3 . The method of  claim 2 , wherein the object is a guidewire.  
     
     
         4 . The method of  claim 2 , wherein the object is a catheter.  
     
     
         5 . The method of  claim 2 , wherein: 
 the object includes a distal end and a proximal end; and    the magnetic material is incorporated into the distal end portion of the object.    
     
     
         6 . The method of  claim 1 , wherein: 
 the magnetic source comprises a first electromagnet; and    the step of disposing the magnetic source adjacent to the body includes supplying the first electromagnet with alternating current of a predetermined frequency to generate the oscillating magnetic field.    
     
     
         7 . The method of  claim 6 , wherein the step of supplying alternating current to the first electromagnet includes supplying alternating current of a frequency sufficient to cause the first electromagnet to oscillate the magnetic field at a frequency sufficient to magnetically induce ultrasonic vibrations in the object.  
     
     
         8 . The method of  claim 6 , wherein the frequency of the alternating current varies.  
     
     
         9 . The method of  claim 8 , wherein the frequency of the alternating current varies over a predetermined range of frequencies.  
     
     
         10 . The method of  claim 8 , wherein the frequency of the alternating current varies continuously over a predetermined range of frequencies.  
     
     
         11 . The method of  claim 8 , wherein the frequency of the alternating current varies over a predetermined range of frequencies by repeatedly increasing from a minimum frequency to a maximum frequency and then decreasing from the maximum frequency to the minimum frequency.  
     
     
         12 . The method of  claim 8 , wherein the frequency of the alternating current varies over a predetermined range of frequencies by repeatedly increasing from a minimum frequency to a maximum frequency.  
     
     
         13 . The method of  claim 8 , wherein the frequency of the alternating current varies over a predetermined range of frequencies by repeatedly decreasing from a maximum frequency to a minimum frequency.  
     
     
         14 . The method of  claim 6 , wherein the amplitude of the alternating current varies.  
     
     
         15 . The method of  claim 14 , wherein the amplitude of the alternating current varies over a predetermined range of amplitudes.  
     
     
         16 . The method of  claim 14 , wherein the amplitude of the alternating current varies continuously over a predetermined range of amplitudes.  
     
     
         17 . The method of  claim 6 , wherein the frequency and the amplitude of the alternating current vary.  
     
     
         18 . The method of  claim 17 , wherein the frequency and the amplitude of the alternating current vary over a predetermined range of frequencies and amplitudes,  
     
     
         19 . The method of  claim 17 , wherein the frequency and the amplitude of the alternating current vary continuously over a predetermined range of frequencies and amplitudes, respectively.  
     
     
         20 . The method of  claim 17 , wherein the frequency and the amplitude of the alternating current vary in a predetermined relationship to one another over a predetermined range of frequencies and amplitudes, respectively.  
     
     
         21 . The method of  claim 6 , comprising the additional steps of: 
 disposing a second electromagnet adjacent to the body and opposite from the first electromagnet; and    supplying the second electromagnet with alternating current at an equal frequency and out-of-phase voltage to the alternating current supplied to the first electromagnet.    
     
     
         22 . The method of  claim 6 , comprising the additional steps of: 
 disposing two or more additional electromagnets adjacent to the body and spaced around the object; and    supplying the two or more additional electromagnets with alternating currents having a frequency equal to that of the alternating current supplied to the first electromagnet and further having voltages out of phase with the voltage of the alternating current supplied to the first electromagnet and to one another.    
     
     
         23 . The method of  claim 1 , wherein the step of disposing the magnetic source adjacent to the body occurs prior to the step of disposing the object into the body.  
     
     
         24 . A method for breaking down tissue within a living body, comprising the steps of: 
 vibrating the tissue; and    repeatedly varying the frequency at which the tissue is vibrated.    
     
     
         25 . The method of  claim 24 , wherein the step of varying the frequency at which the tissue is vibrated comprises repeatedly varying the frequency over a predetermined range of frequencies.  
     
     
         26 . The method of  claim 24 , comprising the additional step of repeatedly varying the amplitude at which the tissue is vibrated.  
     
     
         27 . The method of  claim 26 , wherein the step of varying the amplitude at which the tissue is vibrated comprises repeatedly varying the amplitude over a predetermined range of amplitudes.  
     
     
         28 . The method of  claim 26 , wherein the step of varying the amplitude at which the tissue is vibrated comprises repeatedly varying the amplitude in a predetermined relationship to the varying frequency at which the tissue is vibrated.  
     
     
         29 . The method of  claim 28 , wherein the relationship is a proportional relationship.  
     
     
         30 . The method of  claim 28 , wherein the relationship is an inversely proportional relationship.  
     
     
         31 . A method for breaking down tissue within a living body, comprising the steps of: 
 vibrating the tissue; and    repeatedly varying the amplitude at which the tissue is vibrated.    
     
     
         32 . The method of  claim 31 , wherein the step of varying the amplitude at which the tissue is vibrated comprises repeatedly varying the amplitude over a predetermined range of amplitudes.  
     
     
         33 . A method for inducing motion in a magnetic object disposed within a living body, comprising the steps of: 
 disposing the object within the body;    disposing adjacent to the body a magnetic source to generate a magnetic field to encompass the object with no physical connection to the object; and    causing changes in the magnetic field to magnetically induce motion in the object.    
     
     
         34 . The method of  claim 33 , wherein the change in the magnetic field is caused by a rotational movement of the magnetic source.  
     
     
         35 . The method of  claim 33 , wherein the change in the magnetic field is caused by a vibrating movement of the magnetic source.  
     
     
         36 . The method of  claim 33 , wherein the change in the magnetic field is caused by changing the magnitude of the magnetic field.  
     
     
         37 . The method of  claim 33 , wherein the change in the magnetic field is caused by changing the direction of the magnetic field.  
     
     
         38 . The method of  claim 33 , wherein the change in the magnetic field is caused by changing the magnitude and the direction of the magnetic field.  
     
     
         39 . An assembly for generating vibrations within a living body, comprising: 
 a magnetic object disposed within the body; and    a magnetic field generator disposed adjacent and external to the body with no physical connection to the object for generating an oscillating magnetic field to magnetically induce vibrating motion in the object.    
     
     
         40 . The assembly of  claim 39 , wherein the object comprises magnetic material selected from the group consisting of ferromagnetic and ferrimagnetic materials.  
     
     
         41 . The assembly of  claim 40 , wherein the object is a guidewire.  
     
     
         42 . The assembly of  claim 40 , wherein the object is a catheter.  
     
     
         43 . The assembly of  claim 40 , wherein: 
 the object includes a distal end and a proximal end; and    the magnetic material is incorporated into the distal end portion of the object.    
     
     
         44 . The assembly of  claim 39 , wherein the generator comprises a first electromagnet supplied with alternating current of a predetermined frequency for generating a first oscillating magnetic field to induce motion in the object.  
     
     
         45 . The assembly of  claim 44 , wherein the alternating current is of a frequency sufficient to cause the first electromagnet to oscillate the first magnetic field at a frequency sufficient to magnetically induce ultrasonic vibrations in the object.  
     
     
         46 . The assembly of  claim 44 , further comprising a second electromagnet disposed adjacent to the body and opposite from the first electromagnet and supplied with alternating current at an equal frequency and out-of-phase voltage to the alternating current supplied to the first electromagnet for generating a second magnetic field oscillating out-of-phase with the first magnetic field.  
     
     
         47 . The assembly of  claim 44 , further comprising two or more additional electromagnets disposed adjacent to the body, and spaced around the object and supplied with alternating currents having a frequency equal to that of the alternating current supplied to the first electromagnet and further having voltages out of phase with the voltage of the alternating current supplied to the first electromagnet and to one another for generating magnetic fields oscillating out of phase with each other to magnetically induce three-dimensional vibrating motion in the object.