1. An endoventricular injection catheter with integrated echocardiographic capability, comprising:
an elongated body having a distal end and an imaging core arranged to be inserted into a heart, the imaging core being arranged to transmit ultrasonic energy and to receive reflected ultrasonic energy at the distal end to provide electrical signals representing echocardiographic images to enable cardiac visualization; and
an injector carried on the elongated body with the imaging core, the injector being arranged to inject a therapeutic agent into tissue of the heart visualized by the imaging core.
2. The catheter of claim 1, wherein the elongated body includes a telescoping section to permit longitudinal positioning of the imaging core.
3. The catheter of claim 1, wherein the imaging core is a mechanically rotating imaging core.
4. The catheter of claim 1, further comprising a deflection system that causes the elongated body distal end to deflect in a desired direction.
5. The catheter of claim 4, wherein the deflection system includes a steerable guide sheath.
6. The catheter of claim 4, wherein the deflection system includes a deflection section sheath, a steering ring, at least one steering wire, and a deflection control knob.
7. The catheter of claim 1, wherein the elongated body includes a guide wire lumen for receiving a guide wire.
8. The catheter of claim 7, wherein the guide wire lumen is at the distal end of the elongated body of the catheter.
9. The catheter of claim 7, wherein the guide wire lumen extends along the elongated body of the catheter proximal to the distal end.
10. The catheter of claim 1, wherein the elongated body includes an imaging core lumen and an outer circumferential surface, and wherein the imaging core lumen and the outer surface define a substantially uniform wall thickness of the elongated body over a portion of the elongated body circumference.
11. The catheter of claim 1, wherein the imaging core comprises a plurality of transducers.
12. The catheter of claim 1, further comprising a cannula lumen and wherein the injector includes a cannula received by the cannula lumen and an injection needle within the cannula.
13. The catheter of claim 12, wherein the cannula is formed of a super-elastic material.
14. The catheter of claim 12, further comprising an injection system including the injector, the injection system including a proximal handle, the injection handle including injection controls for extending the cannula, advancing the injection needle, limiting advancement of the injection needle beyond the cannula, and torquing the cannula.
15. The catheter of claim 12, wherein the injection needle includes an end stop that limits advancement of the injection needle within the cannula.
16. The catheter of claim 12, further comprising an injection system including the injector, the injection system further including a reservoir within the cannula and a plunger that forces therapeutic agent into the needle.
17. The catheter of claim 12 wherein the injector comprises a pair of injection needles.
18. The catheter of claim 17 wherein the injector further comprises a fiber optic bundle and an ultraviolet light source for photocrosslinking an injected bioabsorbable polymer solution.
19. A method of providing image-guided transendocardial injection of a therapeutic agent into a left ventricular wall of a heart, comprising:
providing an endoventricular injection catheter having integrated echocardiographic capability, comprising an elongated body having a distal end and an imaging core arranged to be inserted into a heart, the imaging core being arranged to transmit ultrasonic energy and to receive reflected ultrasonic energy at the distal end to provide electrical signals representing echocardiographic images to enable cardiac visualization and an injector carried on the elongated body with the imaging core, the injector being arranged to inject a therapeutic agent into tissue of the heart visualized by the imaging core;
delivering the endoventricular injection catheter into the left ventricle of the heart;
visualizing the left ventricular wall of the heart using the imaging core;
identifying infarct regions of the left ventricle; and
injecting a therapeutic agent into the visualized infarcted regions of the left ventricle using the injector.
20. The method of claim 19, including the further step of injecting a bioabsorbable agent with the injector to prevent back flow of the therapeutic agent.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system for generating a timing signal, the system comprising:
a micro-electromechanical system (MEMS) resonator that includes at least one non-active element and at least one active element, wherein, in operation, wherein the at least one non-active element vibrates and the at least one active element is configured to oscillate in a first resonant mode;
at least one drive electrode configured to receive a first time-varying signal that causes the at least one active element to oscillate;
at least one sense electrode configured to conduct a second time-varying signal in response to the oscillations of the at least one active element; and
at least one resonator electrode shield configured to reduce an interfering signal associated with the at least one non-active element, the at least one drive electrode, or the at least one sense electrode, and wherein the interfering signal is a spurious resonance current conducted by the at least one sense electrode and is related to the vibrations of the at least one non-active element.
2. The system of claim 1, wherein the at least one non-active element comprises a support element or a flexure element.
3. The system of claim 1, wherein the at least one non-active element vibrates in response to the oscillations of the at least on active element.
4. The system of claim 1, wherein the at least one non-active element is a support element, and the first time-varying signal received by the at least one drive electrode causes a time-varying current to be induced in the support element.
5. The system of claim 4, wherein a voltage is applied to the MEMS resonator, and the interfering signal is the current induced in the support element and alters the voltage level of the MEMS resonator.
6. The system of claim 4, wherein the interfering signal is an induced sense current conducted by the at least one sense electrode and is related to the induced current.
7. The system of claim 1, wherein the interfering signal is a feed-through signal conducted by the at least one sense electrode and is capacitively coupled directly from the at least one drive electrode independently of the oscillations of the at least one active element.
8. The system of claim 1, wherein the interfering signal is a current conducted by the at least one sense electrode caused by the at least one active element oscillating in a second resonant mode that is different from the first resonant mode.
9. The system of claim 8, wherein the at least one resonator electrode shield is disposed to cover a portion of the at least one active element that prevents the least one active element from oscillating in a resonant mode that is different from the first resonant mode.
10. The system of claim 1, wherein the resonator electrode shield comprises a conductive material.
11. A system for generating a timing signal, the system comprising:
a tuning fork-configured micro-electromechanical system (MEMS) resonator that includes a support element coupled to one end of a first active element and to one end of a second active element;
a first drive electrode disposed on an outer side of the first active element and configured to receive a first time-varying signal that causes the first active element to oscillate;
a second drive electrode disposed on an outer side of the second active element and configured to receive a second time-varying signal that causes the second active element to oscillate;
a sense electrode disposed on an inner side of the first active element and an inner side of the second active element and configured to conduct a third time-varying signal in response to the oscillations of the first active element and the second active element; and
a first resonator electrode shield disposed between the support element and the sense electrode and configured to reduce an interfering signal associated with the support element.
12. The system of claim 11, wherein the support element vibrates in response to the oscillations of the first active element and the second active element, and the interfering signal is a spurious resonance current conducted by the sense electrode and is related to the vibrations of the support element.
13. The system of claim 11, wherein the first time-varying signal received by the first drive electrode or the second time-varying signal received by the second drive electrode causes a time-varying current to be induced in the support element.
14. The system of claim 13, wherein the interfering signal is an induced sense current conducted by the sense electrode and is related to the time-varying current induced in the support element.
15. The system of claim 11, wherein the first resonator electrode shield comprises a conductive material.
16. The system of claim 11, wherein each of the first drive electrode and the second drive electrode comprises one or more drive electrodes, and the sense electrode comprises one or more sense electrodes.
17. A system for generating a timing signal, the system comprising:
a quad-configured micro-electromechanical system (MEMS) resonator that includes a support element coupled to an isolating spring, which is coupled to one end of a first active element and to one end of a second active element;
a first electrode pair that includes a first electrode disposed on an inner side of the first active element and on one side of the support element, and a second electrode disposed on an outer side of the first active element, wherein either the first electrode or the second electrode is configured to receive a first time-varying signal that causes the first active element to oscillate, and the other electrode is configured to conduct a second time-varying signal in response to the oscillations of the first active element;
a second electrode pair that includes a third electrode disposed on an inner side of the second active element and the other side of the support element, and a fourth electrode disposed on an outer side of the second active element, wherein one electrode is configured to receive a third time-varying signal that causes the second active element to oscillate, and the other electrode is configured to conduct a fourth time-varying signal in response to the oscillations of the second active element; and
a first resonator electrode shield disposed between the first electrode and the support element and configured to reduce an interfering signal associated with either the support element or the isolating spring.
18. The system of claim 17, wherein the first electrode is a sense electrode, the second electrode is a drive electrode, the third electrode is a drive electrode and the fourth electrode is a sense electrode.
19. The system of claim 18, wherein the isolating spring or the support element vibrates in response to the oscillations of the first active element or the second active element, and the interfering signal is a spurious resonance current conducted by the first electrode and is related to the vibrations of the isolating spring or the support element.
20. The system of claim 18, wherein the third time-varying signal received by the third electrode causes a time-varying current to be induced in the support element.
21. The system of claim 20, wherein a voltage is applied to the MEMS resonator, and the interfering signal is the current induced in the support element and alters the voltage level of the MEMS resonator.
22. The system of claim 20, wherein the interfering signal is an induced sense current conducted by the first electrode and is related to the induced current.
23. The system of claim 17, wherein the first electrode is a sense electrode, the second electrode is a drive electrode, the third electrode is a sense electrode and the fourth electrode is a drive electrode.
24. The system of claim 23, wherein the isolating spring or the support element vibrates in response to the oscillations of the first active element or the second active element, and the interfering signal is a spurious resonance current conducted by the first electrode and is related to the vibrations of the isolating spring or the support element.
25. The system of claim 23, wherein the first time-varying signal received by the second electrode andor the third time-varying signal received by the fourth electrode causes a time-varying current to be induced in the support element.
26. The system of claim 25, wherein the interfering signal is an induced sense current conducted by the first electrode and is related to the induced current.
27. The system of claim 17, wherein the first electrode is a drive electrode, the second electrode is a sense electrode, the third electrode is a drive electrode and the fourth electrode is a sense electrode.
28. The system of claim 27, wherein the first time-varying signal received by the first electrode andor the third time-varying signal received by the third electrode causes a time-varying current to be induced in the support element.
29. The system of claim 28, wherein a voltage is applied to the MEMS resonator, and the interfering signal is the current induced in the support element and alters the voltage level of the MEMS resonator.
30. The system of claim 28, wherein the interfering signal is an induced sense current conducted by the second electrode and is related to the induced current.
31. The system of claim 17, wherein the first resonator electrode shield comprises a conductive material.
32. A system for generating a timing signal, the system comprising:
a micro-electromechanical system (MEMS) resonator that includes a first active element, a second active element, and at least one non-active element, wherein, in operation, the first active element and the second active element are configured to oscillate;
a first electrode pair differentially coupled to the first active element and configured to receive a first time-varying signal that causes the first active element and the second active element to oscillate, wherein the first electrode pair includes a first drive electrode disposed on one side of the first active element, and a second drive electrode disposed on the other side of the first active element;
a second electrode pair differentially coupled to the second active element and configured to conduct a second time-varying signal in response to the oscillations of the first active element and the second active element, wherein the second electrode pair includes a first sense electrode disposed on one side of the second active element, and a second sense electrode disposed on the other side of the second active element; and
a first resonator electrode shield configured to reduce an interfering signal associated with either the first electrode pair, the second electrode pair, or the at least one non-active element.
33. The system of claim 32, wherein the at least one non-active element vibrates, and the interfering signal is a spurious resonance current conducted by the second electrode pair and is related to the vibrations of the at least one non-active element.
34. The system of claim 33, wherein the at least one non-active element comprises a support element or a flexure element.
35. The system of claim 33, wherein the at least one non-active element vibrates in response to the oscillations of the first active element or the second active element or in response to the first time-varying signal received by the first electrode pair.
36. The system of claim 32, wherein the at least one non-active element is a support element, and the first time-varying signal received by the first electrode pair causes a time-varying current to be induced in the support element.
37. The system of claim 36, wherein a voltage is applied to the MEMS resonator, and the interfering signal is the current induced in the support element and alters the voltage level of the MEMS resonator.
38. The system of claim 36, wherein the interfering signal is an induced sense current conducted by the second electrode pair and is related to the induced current.
39. The system of claim 32, wherein the interfering signal is a feed-through signal conducted by the second electrode pair and is capacitively coupled directly from the first electrode pair independently of the oscillations of the at least one active element.
40. The system of claim 32, wherein the system further comprises:
a third active element; and
a third electrode pair differentially coupled to the third active element and configured to receive a third time-varying signal that causes the third active element to oscillate,
wherein the interfering signal is a feed-through signal received by the first electrode pair and is capacitively coupled directly from the third electrode pair.
41. The system of claim 32, wherein the interfering signal is a current conducted by the second electrode pair and is related to a parasitic capacitance.
42. The system of claim 32, wherein the resonator electrode shield comprises a conductive material.