Intravascular rotary blood pump

Abstract

An intravascular rotary blood pump possesses a catheter (10), a pumping device (50) disposed distally of the catheter and having at its distal end a flexible flow cannula (53) through which blood is either sucked or discharged by the pumping device (50) during operation of the blood pump, and at least one pressure sensor (27, 28A, 30) having at least one optical fiber (28A) which is laid along the flow cannula (53). The optical fiber (28A) and, where applicable, a sliding tube (27) in which the optical fiber (28A) is laid extend along a neutral fiber of the flow cannula (53).

The invention claimed is: 
     
       1. An intravascular rotary blood pump, comprising a catheter ( 10 ), a pumping device ( 50 ) disposed distally of the catheter ( 10 ) and having at its distal end a flexurally flexible flow cannula ( 53 ) through which blood is either sucked or discharged by the pumping device ( 50 ) during operation of the blood pump, and at least one pressure sensor ( 27 ,  28 A,  30 ) having at least one optical fiber ( 28 A), characterized in that the optical fiber ( 28 A) is laid along a neutral fiber of the flow cannula ( 53 ). 
     
     
       2. The blood pump according to  claim 1 , wherein the neutral fiber is preset by a precurvature of the flow cannula ( 53 ) and accordingly lies between an inner radius of curvature and outer radius of curvature of the flow cannula as defined by the precurvature. 
     
     
       3. The blood pump according to  claim 1 , wherein the optical fiber ( 28 A) is bonded along the neutral fiber. 
     
     
       4. The blood pump according to  claim 1 , wherein the optical fiber ( 28 A) is laid freely movably in a sliding tube ( 27 ) along the neutral fiber. 
     
     
       5. The blood pump according to  claim 4 , wherein the sliding tube ( 27 ) extends along the flow cannula ( 53 ) on the outside. 
     
     
       6. The blood pump according to  claim 4 , wherein an outer surface of the optical fiber ( 28 A) and an inner surface of the sliding tube ( 27 ) form a sliding material pairing of metal-metal, metal-plastic or plastic-plastic. 
     
     
       7. The blood pump according to  claim 6 , wherein the plastic comprises polytetrafluoroethylene (PTFE). 
     
     
       8. The blood pump according to  claim 4 , wherein the sliding tube ( 27 ) is formed from a material comprising a shape-memory alloy. 
     
     
       9. The blood pump according to  claim 4 , wherein the sliding tube ( 27 ) is plastic-coated on the inside. 
     
     
       10. The blood pump according to  claim 4 , wherein the optical fiber ( 28 A) has an outer metal coating ( 28   coat ). 
     
     
       11. The blood pump according to  claim 4 , wherein the optical fiber ( 28 A) has an outer plastic coating ( 28   coat ) made of polytetrafluoroethylene (PTFE). 
     
     
       12. The blood pump according to  claim 4 , wherein the sliding tube ( 27 ) is filled with liquid. 
     
     
       13. The blood pump according to  claim 1 , wherein the optical fiber ( 28 A) comprises a glass fiber ( 28   core ,  28   clad ,  28   coat ). 
     
     
       14. The blood pump according to  claim 1 , wherein the optical fiber ( 28 A) possesses a diameter of 130 μm or less. 
     
     
       15. The blood pump according to  claim 1 , wherein the flow cannula ( 53 ) has an outer surface in which there is configured a depression ( 36 ) in which a distal end ( 30 ) of the pressure sensor is at least partly disposed. 
     
     
       16. The blood pump according to  claim 1 , wherein the flexurally flexible flow cannula ( 53 ) has a soft-flexible tip ( 55 ) and wherein a distal end ( 30 ) of the pressure sensor is at least partly disposed in the soft-flexible tip ( 55 ). 
     
     
       17. The blood pump according to  claim 1 , wherein a distal end ( 30 ) of the pressure sensor projects radially beyond the periphery of the flow cannula ( 53 ), and wherein there is provided on the flow cannula ( 53 ) distally before the distal end ( 30 ) of the pressure sensor a bulge ( 35 ) likewise projecting beyond the periphery of the flow cannula ( 53 ). 
     
     
       18. An intravascular rotary blood pump, comprising:
 a catheter (10),   a pumping device (50) disposed distally of the catheter (10) and having at its distal end a flexurally flexible flow cannula (53) through which blood is either sucked or discharged by the pumping device (50) during operation of the blood pump, and   at least one pressure sensor (27, 28A, 30) having at least one optical fiber (28A) fixed along a neutral fiber of the flow cannula (53) selected to prevent breakage of the fiber (28A) during bending of the flow cannula (53) while the blood pump is guided through a vascular system of a patient, wherein the neutral fiber of the flow cannula (53) is formed by locally strengthening the flow cannula.    
     
     
       19. The blood pump according to  claim 18 , wherein the cannula is strengthened by a tube (27) that extends through walling of the flow cannula (53).  
     
     
       20. The blood pump according to  claim 18 , wherein the cannula is strengthened by a tube (27) that extends along an outer surface of the flow cannula (53).  
     
     
       21. The blood pump according to  claim 18 , wherein the optical fiber (28A) is configured to undergo substantially no extension while the blood pump is guided through the vascular system of the patient.  
     
     
       22. The blood pump according to  claim 18 , wherein the optical fiber (28A) is configured to undergo substantially no compression while the blood pump is guided through the vascular system of the patient.  
     
     
       23. The blood pump according to  claim 18 , wherein the optical fiber (28A) is locally strengthened by applying a stiff strip along the flow cannula.  
     
     
       24. The blood pump according to  claim 23 , wherein the stiff strip is one of flexurally stiff, tensilely stiff, or compressively stiff.