1-18. (canceled)
19. A dual lumen cannula comprising:
a first infusion tube having a first elongate body defining a first lumen therethrough, the first infusion tube having a first proximal end, a first distal end, and a first sidewall extending circumferentially therebetween;
a second drainage tube aligned with the first infusion tube and having a second elongate body with a second lumen, the second drainage tube having a second proximal end, a second distal end, and a second sidewall extending circumferentially therebetween;
a plurality of infusion apertures extending through the first sidewall of the first infusion tube; and
a plurality of drainage apertures extending through the second sidewall of the second drainage tube,
wherein a total cross-sectional area of the plurality of infusion apertures is equal to or greater than the cross-sectional area of the first lumen, and
wherein the total cross-sectional area of the plurality of drainage apertures is equal to or greater than the cross-sectional area of the second lumen.
20. The dual lumen cannula of claim 19, wherein the second drainage tube is coaxially aligned with the first infusion tube.
21. The dual lumen cannula of claim 19, wherein the plurality of infusion apertures is provided at the first distal end of the first infusion tube.
22. The dual lumen cannula of claim 19, wherein the plurality of drainage apertures is provided at the second distal end of the second drainage tube.
23. The dual lumen cannula of claim 19, wherein the plurality of infusion apertures extends through the first sidewall of the first infusion tube in a direction perpendicular to a longitudinal axis of the first infusion tube.
24. The dual lumen cannula of claim 19, wherein the plurality of drainage apertures extends through the second sidewall of the second drainage tube in a direction perpendicular to a longitudinal axis of the second drainage tube.
25. The dual lumen cannula of claim 19, wherein the plurality of infusion apertures extends through the first sidewall of the first infusion tube at an acute or obtuse angle with respect to a longitudinal axis of the first infusion tube.
26. The dual lumen cannula of claim 19, wherein the plurality of drainage apertures extends through the second sidewall of the second drainage tube at an acute or obtuse angle with respect to a longitudinal axis of the second drainage tube.
27. The dual lumen cannula of claim 19, further comprising a reinforcing coil that extends from the proximal end to the distal end of one or both of the first infusion tube and the second drainage tube.
28. The dual lumen cannula of claim 19, wherein the dual lumen cannula is adapted for inserting into an internal jugular vein of a patient.
29. The dual lumen cannula of claim 19, wherein the dual lumen cannula is adapted for maneuvering through the patient’s vasculature such that the first distal end of the first infusion tube is substantially within the patient’s pulmonary artery and such that the second distal end of the second drainage tube is substantially within the patient’s right atrium.
30. The dual lumen cannula of claim 19, wherein at least one of the plurality of infusion apertures and the plurality of drainage apertures extends in a circular pattern.
31. The dual lumen cannula of claim 19, wherein the plurality of infusion apertures is separated from the plurality of drainage apertures by a predetermined distance along a longitudinal axis of the first infusion tube, and wherein the predetermined distance is selected based on at least one of patient age, patient size, and desired flow rate.
32. The dual lumen cannula of claim 19, wherein a tapered portion of an internal portion of the first infusion tube extends distally beyond a circumferentially-disposed infusion aperture that is positioned closest to the first distal end of the first infusion tube.
33. A dual lumen cannula comprising:
a first infusion tube having a first elongate body defining a first lumen therethrough, the first infusion tube having a first proximal end, a first distal end, and a first sidewall extending circumferentially therebetween;
a second drainage tube aligned with the first infusion tube and having a second elongate body with a second lumen, the second drainage tube having a second proximal end, a second distal end, and a second sidewall extending circumferentially therebetween;
a plurality of infusion apertures extending through the first sidewall of the first infusion tube;
a plurality of drainage apertures extending through the second sidewall of the second drainage tube;
a connector;
a first connector portion provided at the first proximal end of the first infusion tube for coupling the first infusion tube to the connector;
a second connector portion provided at the second proximal end of the second drainage tube for coupling the second drainage tube to the connector,
wherein the first connector portion and the second connector portion are removably connected to the connector for coupling the first infusion tube and the second drainage tube to an extracorporeal blood circuit,
wherein a total cross-sectional area of the plurality of infusion apertures is equal to or greater than the cross-sectional area of the first lumen, and
wherein the total cross-sectional area of the plurality of drainage apertures is equal to or greater than the cross-sectional area of the second lumen.
34. The dual lumen cannula of claim 33, wherein the second drainage tube is coaxially aligned with the first infusion tube.
35. The dual lumen cannula of claim 33, wherein the plurality of infusion apertures is provided at the first distal end of the first infusion tube.
36. The dual lumen cannula of claim 33, wherein the plurality of drainage apertures is provided at the second distal end of the second drainage tube.
37. The dual lumen cannula of claim 33, wherein the plurality of infusion apertures extends through the first sidewall of the first infusion tube in a direction perpendicular to a longitudinal axis of the first infusion tube.
38. The dual lumen cannula of claim 33, wherein the plurality of drainage apertures extends through the second sidewall of the second drainage tube in a direction perpendicular to a longitudinal axis of the second drainage tube.
39. The dual lumen cannula of claim 33, wherein the plurality of infusion apertures extends through the first sidewall of the first infusion tube at an acute or obtuse angle with respect to a longitudinal axis of the first infusion tube.
40. The dual lumen cannula of claim 33, wherein the plurality of drainage apertures extends through the second sidewall of the second drainage tube at an acute or obtuse angle with respect to a longitudinal axis of the second drainage tube.
41. The dual lumen cannula of claim 33, further comprising a reinforcing coil that extends from the proximal end to the distal end of one or both of the first infusion tube and the second drainage tube.
42. The dual lumen cannula of claim 33, wherein the dual lumen cannula is adapted for inserting into an internal jugular vein of a patient.
43. The dual lumen cannula of claim 33, wherein the dual lumen cannula is adapted for maneuvering through the patient’s vasculature such that the first distal end of the first infusion tube is substantially within the patient’s pulmonary artery and such that the second distal end of the second drainage tube is substantially within the patient’s right atrium.
44. The dual lumen cannula of claim 33, wherein at least one of the plurality of infusion apertures and the plurality of drainage apertures extends in a circular pattern.
45. The dual lumen cannula of claim 33, wherein the plurality of infusion apertures is separated from the plurality of drainage apertures by a predetermined distance along a longitudinal axis of the first infusion tube, and wherein the predetermined distance is selected based on at least one of patient age, patient size, and desired flow rate.
46. The dual lumen cannula of claim 33, wherein a tapered portion of an internal portion of the first infusion tube extends distally beyond a circumferentially-disposed infusion aperture that is positioned closest to the first distal end of the first infusion tube.
47. The dual lumen cannula of claim 33, wherein the connector further comprises a distal aperture in fluid communication with an inlet portion and an outlet portion, and a barbed fitting on the inlet portion and the outlet portion for connecting an infusion line and a drainage line to the connector.
48. A method of assisting a patient’s heart, comprising the steps of:
providing a dual lumen cannula comprising:
a first infusion tube having a first elongate body defining a first lumen therethrough, the first infusion tube having a first proximal end, a first distal end, and a first sidewall extending circumferentially therebetween;
a second drainage tube aligned with the first infusion tube and having a second elongate body with a second lumen, the second drainage tube having a second proximal end, a second distal end, and a second sidewall extending circumferentially therebetween;
a plurality of infusion apertures in the first sidewall of the first infusion tube;
a plurality of drainage apertures in the second sidewall of the second drainage tube;
a connector;
a first connector portion provided at the proximal end of the first infusion tube for coupling the first infusion tube to the connector;
a second connector portion provided at the proximal end of the second drainage tube for coupling the second drainage tube to the connector,
wherein the first connector portion and the second connector portion are removably connected to the connector for coupling the first infusion tube and the second drainage tube to an extracorporeal blood circuit,
wherein a total cross-sectional area of the plurality of infusion apertures is equal to or greater than the cross-sectional area of the first lumen, and
wherein the total cross-sectional area of the plurality of drainage apertures is equal to or greater than the cross-sectional area of the second lumen;
inserting the dual lumen cannula into an internal jugular vein of the patient, the dual lumen cannula having a length to extend from the patient’s neck area to the patient’s heart;
maneuvering the dual lumen cannula through the patient’s vasculature such that the first distal end of the first infusion tube is substantially within the patient’s pulmonary artery and such that the second distal end of the second drainage tube is substantially within the patient’s right atrium; and
connecting the connector to a blood pump for establishing right ventricular support.
49. The method of claim 48, wherein blood from the blood pump is delivered to the patient’s pulmonary artery through the plurality of infusion apertures in the first infusion tube.
50. The method of claim 48, wherein blood is withdrawn from the patient’s right atrium through the plurality of drainage apertures in the second drainage tube.
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 battery charging system for a vehicle comprising:
electric motor configured to draw current to operate as a drive motor for a vehicle and to supply current for regenerative braking;
a first battery connected to the electric motor;
a second battery;
a battery charger connected to the second battery; and
a current limiting buffer connecting the first battery in parallel with second battery, the current limiting buffer comprising:
a connecting transistor having a current path connecting the first battery in parallel with the second battery and having a control terminal; and
a control circuit connected between the first battery and the second battery, and to the control terminal of the connecting transistor, the control circuit for determining a voltage difference between the first and the second batteries, and applying a voltage to the control terminal to control the amount of current flow between the first battery and the second battery.
2. The battery charging system of claim 1, wherein the control circuit comprises:
a sensing resistor having a first terminal connected to the first battery and having a second terminal connected by a current path of the connecting transistor to the second battery;
a control transistor having a current path connected from the second terminal of the sensing resistor to the control terminal of the connecting transistor, and having a control terminal connected to the first terminal of the sensing resistor.
3. The battery charging system of claim 2,
wherein the connecting transistor comprises a CMOS transistor having a source-drain path forming the current path, and a gate forming the control terminal, and
wherein the control transistor comprises a CMOS transistor having a source-drain path forming the current path, and a gate forming the control terminal.
4. The battery charging system of claim 2,
wherein the connecting transistor comprises a BJT transistor having a collector-emitter path forming the current path, and a base forming the control terminal, and
wherein the control transistor comprises a BJT transistor having a collector-emitter path forming the current path, and a base forming the control terminal.
5. The battery charging system of claim 1, wherein the control circuit comprises:
a sensing resistor having a first terminal connected to the first battery and having a second terminal connected by a current path of the connecting transistor to the second battery; and
a differential amplifier having a first input connected to the first terminal of the sensing resistor, a second input connected to the second terminal of the sensing resistor, and an output connected to the control terminal of the connecting transistor.
6. The battery charging system of claim 1, further comprising a diode buffer connecting the first battery and the second battery.
7. The battery charging system of claim 1, wherein the current limiting buffer comprises a bi-directional buffer.
8. The battery charging system of claim 7,
wherein the connecting transistor comprises a first connecting transistor, the battery charging system further comprising a second connecting transistor having a current path and a control terminal, and
wherein the control circuit comprises:
a sensing resistor having a first terminal connected by a current path of the first connecting transistor to the first battery and having a second terminal connected by a current path of the second connecting transistor to the second battery;
a first control transistor having a current path connected from the second terminal of the sensing resistor to the control terminal of the first connecting transistor, and having a control terminal connected to the first terminal of the sensing resistor; and
a second control transistor having a current path connected from the first terminal of the sensing resistor to the control terminal of the second connecting transistor, and having a control terminal connected to the second terminal of the sensing resistor.
9. The battery charging system of claim 8, wherein the first and second connecting transistors and the first and second control transistors each comprise at least one of a BJT transistor and a CMOS transistor.
10. The battery charging system of claim 7,
wherein the connecting transistor comprises a first connecting transistor, the battery charging system further comprising a second connecting transistor having a current path and a control terminal, and
wherein the control circuit comprises:
a sensing resistor having a first terminal connected by a current path of the first connecting transistor to the first battery and having a second terminal connected by a current path of the second connecting transistor to the second battery; and
a differential amplifier having a first input connected to the first terminal of the sensing resistor, a second input connected to the second terminal of the sensing resistor, a first output connected to the control terminal of the first connecting transistor and a second output complementary to the first output connected to the control terminal of the second connecting transistor.
11. A method for charging a battery charging for a vehicle comprising:
providing an electric motor configured to draw current to operate as a drive motor for a vehicle and to supply current for regenerative braking;
providing a first battery connected to the electric motor;
providing a second battery;
providing a battery charger connected to the second battery; and
providing a transistor with a current path connecting the first battery in parallel with the second battery, the transistor having a current control terminal; and
controlling voltage on the control terminal of the transistor to limit the amount of current flow between the first battery and the second battery.
12. The method of claim 11, wherein the control voltage is applied to the control terminal of the transistor to limit current in both directions between the first battery and the second battery.
13. The method of claim 11, further comprising:
measuring current flow through a resistor connected between the first battery and the second battery and controlling the voltage on the control terminal based on the measured current flow.
14. The method of claim 11, wherein the step of controlling voltage limits current flow by clamping the current flow to a maximum value.