Device for traversing vessel occlusions and method of use

Abstract

An apparatus, system and method for re-canalization or opening a passage through an occlusion in a blood vessel is provided. The apparatus and method, which are appropriate for both cardiovascular as well as peripheral vessels, use a pulling member and a spring element, for example a compression spring, to oscillate a vibratable member, and the system of the invention includes the apparatus and a control unit to permit the frequency or amplitude of oscillation of the vibratable member to be adjusted. Also provided is a method for oscillating a vibratable member using a pulling member and a spring element. The apparatus and system are useful not only for penetrating a total or partial occlusion, but also to improve deliverability of a catheter through a partially occluded vessel or a tortuous vessel.

What is claimed is: 
     
         1 . An apparatus, comprising:
 a catheter, having a proximal end and a distal end;   a spring element having a proximal end and a distal end, said proximal end of said spring element being affixed to said distal end of said catheter;   a pulling member located within said catheter, said pulling member having a proximal end and a distal end, said distal end of said pulling member affixed to a distal component;   a vibratable member; and   a vibrational energy source operably connected to said proximal end of said pulling member, wherein said vibrational energy source is adapted to generate at least one oscillation in said vibratable member via said pulling member and said spring element by pulling said pulling member.   
     
     
         2 . The apparatus of  claim 1 , wherein said pulling member is a flexible string. 
     
     
         3 . The apparatus of  claim 1 , wherein said distal component is said vibratable member. 
     
     
         4 . The apparatus of  claim 1 , wherein said distal component is said distal end of said spring element. 
     
     
         5 . The apparatus of  claim 1 , wherein said vibratable member is a cap, and said cap is affixed to said distal end of said spring element. 
     
     
         6 . The apparatus of  claim 1 , wherein said spring element is selected from the group consisting of: a compression spring, a helical spring, a leaf spring, a bellows, a compressible polymer, and an elastic membrane. 
     
     
         7 . The apparatus of  claim 1 , wherein said vibrational energy source is selected from the group consisting of: an engine having a reciprocating member, a shaker, an actuator, and a solenoid. 
     
     
         8 . The apparatus according to  claim 1 , further comprising a catheter anchoring device. 
     
     
         9 . The apparatus according to  claim 8 , wherein said catheter anchoring device is an expandable balloon. 
     
     
         10 . A system, comprising:
 the apparatus of any one of  claims 1 - 9 ; and   a control unit adapted to control said vibrational energy source.   
     
     
         11 . The system according to  claim 10 , wherein said oscillation comprises at least one frequency and at least one amplitude, and said at least one frequency and at least one amplitude are independently adjustable via said control unit. 
     
     
         12 . The system according to  claim 10 , further comprising a sensor, and a processor functionally connected to said sensor and operably connected to said control unit, said processor being capable of analyzing input from said sensor. 
     
     
         13 . The system according to  claim 10 , further comprising a tension adjustment mechanism to compensate for variations in pulling member path length when said catheter includes curvatures. 
     
     
         14 . A method of oscillating a vibratable member comprising:
 pulling a pulling member from a proximal end of said pulling member to generate a load that compresses a distal end of a spring member toward a proximal end of said spring member, said pulling member attached at a distal end to said distal end of said spring member, said spring member attached at a proximal end to a distal end of a catheter, said catheter housing said pulling member, wherein said vibratable member is functionally attached to said distal end of said spring element;   releasing said load generated by said pulling member, thereby permitting said spring element to expand;   repeating said pulling and releasing steps to effect oscillation of said vibration member.   
     
     
         15 . The method of  claim 14 , wherein said pulling and releasing steps are performed by a vibrational energy source. 
     
     
         16 . The method of  claim 15 , wherein said oscillation has at least one frequency and at least one amplitude, wherein said at least one frequency is controlled by a control unit functionally attached to said vibrational energy source. 
     
     
         17 . The method of  claim 16 , wherein said oscillation has at least one frequency and at least one amplitude, wherein said at least one amplitude is controlled by a control unit functionally attached to said vibrational energy source. 
     
     
         18 . A method of controlling a force of vibration in an apparatus, said method comprising:
 a) receiving initial control parameters;   b) initiating a vibration iteration cycle comprising at least one pull and release of a pulling member by a vibrational energy source sufficient to vibrate a vibratable member at a vibration force (F), wherein said pulling member is attached to a distal component located at a distal end of a spring element and at a proximal end to said vibration energy source, wherein said spring element is attached at a proximal end to a distal end of a catheter, said catheter houses said pulling member, and said vibratable member is attached to said distal end of said spring element, and wherein said pull and release of said pulling member effects a compression and expansion of said spring element;   c) receiving an achieved amplitude value input for said vibration iteration cycle; and   d) adjusting said vibration force in accordance with said achieved amplitude value.   
     
     
         19 . The method of  claim 18 , wherein said receiving initial control parameters includes (i) receiving a target amplitude value input; ii) receiving a maximum amplitude value input; iii) receiving an initial frequency value input; iv) receiving a maximum frequency value input; and v) receiving a maximum iteration value input. 
     
     
         20 . The method of  claim 18 , wherein said initiating includes (i) initializing an iteration count to zero; and (ii) commencing said vibration iteration cycle in said apparatus, wherein said at least one pull and release occurs at an initial frequency and a target amplitude. 
     
     
         21 . The method of  claim 18 , wherein said adjusting includes (i) comparing said achieved amplitude value to a target amplitude value and to a maximum amplitude value; (ii) increasing an iteration count by one when said achieved amplitude value is less than said target amplitude value, setting said iteration count to zero when said achieved amplitude value is not less than said target amplitude value, and stopping said vibration iteration cycle when said achieved amplitude value is not less than said target amplitude value and not less than said maximum amplitude value; and (iii) increasing said force of vibration by increasing a frequency gain and/or an amplitude gain by about 2-5% in accordance with the equation F=A i ׃ i   2  to generate a new working frequency (ƒ i ) and/or a new working amplitude (A i ) if said iteration count is increased by one. 
     
     
         22 . The method of  claim 21 , further comprising:
 e) comparing said iteration count to a maximum iteration value, comparing said working amplitude to a maximum amplitude value, and comparing said working frequency to a maximum frequency value; f) initiating a new vibration iteration cycle in said apparatus: if said iteration count is less than said iteration maximum value, or if said working amplitude is less than said maximum amplitude value and said working frequency is less than said maximum frequency value; and g) stopping said vibration iteration cycle: if said iteration count is not less than said iteration maximum value, and if said working amplitude is not less than said maximum amplitude value or said working frequency is not less than said maximum frequency value.   
     
     
         23 . A method of traversing a vessel occlusion comprising:
 introducing into said vessel the apparatus of  claims 1 ; and   generating a series of pulling forces from said vibrational energy source upon said pulling member to oscillate said vibratable member.   
     
     
         24 . The method of  claim 23 , further including:
 positioning said distal end of said catheter in contact with said occlusion;   wherein said vibratable member is oscillated at an amplitude and frequency sufficient to penetrate said occlusion.   
     
     
         25 . The method of  claim 24 , further including advancing said apparatus through said occlusion as said vibratable member penetrates said occlusion. 
     
     
         26 . The method of  claim 23 , wherein said vibratable member is oscillated at an amplitude and frequency sufficient to maneuver said catheter around obstacles in said vessel. 
     
     
         27 . A method of improving deliverability of a catheter, comprising:
 introducing into a vessel having tortuous segments the apparatus of  claim 1 ;   generating a series of pulling forces from said vibrational energy source upon said pulling member to oscillate said vibratable member at an amplitude and frequency sufficient to maneuver said catheter through said tortuous segments.