Low-power tissue sealing device and method
A surgical system and method for fusing tissue are disclosed. The system has an electrosurgical generator capable of delivering electrosurgical power, a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer the electrosurgical power from the electrosurgical generator to a distal end of the surgical instrument, and a power control circuit for controlling the delivery of radio frequency energy to the tissue in contact with the distal end of the surgical instrument. The surgical system is configured to: deliver the radio frequency energy at a non-pulsing power to the tissue for a period of time of 3 seconds or less, wherein the non-pulsing power is held constant, the output current is held under 2 Amperes RMS, and the output voltage is held under 100 Volts RMS, the non-pulsing power further causing the tissue to begin to desiccate and to fuse within the period of time.
1. A surgical system for fusing tissue, the surgical system comprising:
an electrosurgical generator capable of delivering electrosurgical power;
a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer the electrosurgical power from the electrosurgical generator to a distal end of the surgical instrument, wherein the distal end of the surgical instrument has a pair of end effectors; and
a power control circuit configured to control the delivery of radio frequency energy to the tissue disposed between the pair of end effectors;
wherein the power control circuit is further configured to: deliver the radio frequency energy at a non-pulsing power to the tissue for a period of time of 3 seconds or less, wherein the period of time is measured from the beginning of the application of the non-pulsing power and continues through fusing of the tissue, wherein the output current is held under 2 Amperes RMS, and the output voltage is held under 100 Volts RMS, the non-pulsing power further applying a current density of 0.1 Amperes per square millimeter or less to the tissue, the non-pulsing power further causing the tissue to begin to desiccate and to fuse within the period of time.
2. The surgical system of claim 1 , wherein the radio frequency energy is delivered to the tissue with a current density of 0.04 Amperes per square millimeter or less.
3. The surgical system of claim 1 , wherein the surgical system is configured to:
calculate an impedance of the tissue being fused; and
limit the flow of non-pulsing power when the impedance of the tissue being fused reaches a set impedance threshold within the period of time.
4. The surgical system of claim 1 , wherein the surgical system is configured to:
calculate an impedance of the tissue being fused during the period of time; and
terminate the flow of the non-pulsing power when the impedance of the tissue being fused reaches a predetermined level.
5. The surgical system of claim 1 , wherein each end effector of the pair of end effectors has a contacting surface area of less than 42 square millimeters.
6. The surgical system of claim 5 , wherein the contacting surface area is between 8 and 22 square millimeters.
7. The surgical system of claim 1 , wherein the non-pulsing power has an output current of between 0.2 and 1.75 Amperes RMS.
8. The surgical system of claim 1 , wherein the non-pulsing power has an output current of between 0.75 and 1.00 Amperes RMS.
9. The surgical system of claim 1 , wherein the non-pulsing power has a power output of 35 Watts or less.
10. The surgical system of claim 1 , wherein the non-pulsing power has an output voltage of between 70and 90 Volts RMS.
11. The surgical system of claim 1 , wherein the pair of end effectors are adapted to apply between 172 and 862 kPa of pressure to the tissue being fused.
12. The surgical system of claim 11 , wherein the surgical system is configured to deliver the radio frequency energy at the non-pulsing power at a power of 35 Watts or less.
13. The surgical system of claim 1 , wherein the pair of end effectors adapted to at least one of: compress the tissue being fused between a gap of greater than 0.0 millimeters and 0.127 millimeters or less; or apply between 448 and 758 kPa of pressure to the tissue being fused.
14. The surgical system of claim 1 , wherein the pair of end effectors are adapted to: compress the tissue to a gap of greater than 0.0 millimeters and less than or equal to 0.127 millimeters; and apply pressure to the tissue therebetween 448 and 758 kPa.
15. A power control system for delivering radio frequency energy to a surgical instrument, the power control system comprising:
a power supply for delivering an output voltage and an output current to a distal end of the surgical instrument, wherein the distal end of the surgical instrument has a pair of end effectors;
a sensing circuit for detecting parameters indicative of an impedance of a tissue portion being fused; and
a power sequencing module for automatically sequencing an electrosurgical power delivered to the surgical instrument;
wherein the power sequencing module is adapted to:
apply non-pulsing power to the tissue portion disposed between the pair of end effectors for a period of time of 3 seconds or less, wherein the period of time is measured from beginning application of the application of the non-pulsing power through the beginning of a desiccation of the tissue portion and through a drying out and the fusing of the tissue portion, and wherein the output current is held under 2 Amperes RMS, and- the output voltage is held under 100 Volts RMS, and the output current applies a current density of 0.1 Amperes per square millimeter or less to the tissue portion being fused.
16. The power control system of claim 15 , wherein the power sequencing module is adapted to terminate the flow of the non-pulsing power to the tissue portion being fused when the impedance of the tissue being fused reaches 150 ohms or more.
17. The power control system of claim 15 , wherein the power sequencing module is further adapted to calculate an impedance of the tissue portion being fused through the sensing circuit during the period of time; and limit the flow of the non-pulsing power to the tissue portion being fused by between 60 and 80% when the impedance of the tissue portion being fused reaches a set impedance threshold within the period of time.
18. The power control system of claim 15 , wherein the power sequencing module is further adapted to reduce the non-pulsing power to the tissue portion being fused for a predetermined length of time prior to terminating the flow of the non-pulsing power to the tissue portion being fused.
19. The power control system of claim 15 , wherein the power sequencing module is further adapted to calculate the impedance of the tissue portion being fused through the sensing circuit during the period of time; and
terminating the flow of the non-pulsing power to the tissue portion being fused when the impedance of the tissue portion being fused reaches a predetermined level.
20. The power control system of claim 15 , wherein the power sequencing module is further adapted to:
hold the non-pulsing power to 35 Watts or less.
21. The power control system of claim 15 , wherein the power sequencing module is adapted to apply the-non-pulsing power to the tissue being fused with the current density of about 0.034 Amperes per square millimeter or more.
22. The power control system of claim 15 , wherein the power sequencing module is adapted to apply the non-pulsing power to the tissue being fused with the current density of about 0.04 Amperes per square millimeter.
23. The power control system of claim 15 , wherein the power sequencing module is adapted to apply the non-pulsing power at a power of 35 Watts or less.
24. A surgical system for fusing tissue, the surgical system comprising:
an electrosurgical generator capable of delivering electrosurgical power;
a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer electrosurgical power from the electrosurgical generator to a distal end of the surgical instrument, wherein the distal end of the surgical instrument has a pair of end effectors; and
a power control circuit configured to control the delivery of radio frequency energy to the tissue disposed between the pair of end effectors; wherein the power control circuit is further configured to
deliver a radio frequency energy to the tissue, the radio frequency energy having a non-pulsed power having an output current and an output voltage; and
apply the non-pulsed power to the tissue for a period of time while the output current is held under 2 Amperes RMS, and the output voltage is held under 100 Volts RMS, wherein the period of time is measured from beginning of the application of the non-pulsed power through fusing of the tissue, and the non-pulsed power applies a current density of 0.1 Amperes per square millimeter or less to the tissue, and the non-pulsed power further causes the tissue to begin to desiccate within the period of time, wherein the period of time is 3 seconds or less.
25. The surgical system of claim 24 , wherein each end effector of the pair of end effectors has a contacting surface area of less than 42 square millimeters.
26. The surgical system of claim 24 , wherein the power control circuit is further configured to: calculate an impedance of the tissue being fused; limit the flow of the non-pulsed power when the impedance of the tissue being fused reaches a set impedance threshold; and terminate the flow of the non-pulsed power when the impedance of the tissue being fused reaches a predetermined level indicative that the tissue being fused is desiccated.
27. The surgical system of claim 24 , wherein the power control circuit is further configured to: limit the output voltage to a maximum of between 70 and 85 Volts.
28. A method of fusing tissue, the method comprising:
providing a surgical system having an electrosurgical generator and a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer electrosurgical power from the electrosurgical generator to a distal end of the surgical instrument, wherein the distal end of the surgical instrument has a pair of end effectors;
positioning the tissue between the pair of end effectors;
delivering a radio frequency energy to the tissue, the radio frequency energy having a non-pulsed power having an output current and an output voltage; and
applying the non-pulsed power to the tissue for a period of time, the output current is held under 2 Amperes RMS, and the output voltage is held under 100 Volts RMS, wherein the period of time is measured from the beginning of the application of the non-pulsed power and continues through fusing of the tissue, and the non-pulsed power causes the tissue to begin to desiccate within the period of time, wherein the period of time is 3 seconds or less, and wherein the non-pulsed power applies a current density of 0.1 Amperes per square millimeter or less to the tissue.
29. The method of claim 28 , further comprising:
limiting the output voltage to a maximum of between 70 and 85 Volts; and
limiting the non-pulsed power to a maximum of 35 Watts.
30. The method of claim 28 , further comprising:
terminating the flow of the non-pulsed power to the tissue being fused when an impedance of the tissue being fused reaches 150 ohms or more.
31. The method of claim 28 , further comprising:
terminating the flow of non-pulsed power when an impedance of the tissue being fused reaches a predetermined level indicative that the tissue being fused is desiccated.
32. The method of claim 28 , further comprising at least one of:
compressing the tissue to a gap of greater than 0.0 millimeters and less than or equal to 0.127 millimeters; or
applying pressure of between 448 and 758 kPa to compress the tissue between the pair of end effectors on the surgical instrument.
33. The method of claim 28 , wherein the step of applying the non-pulsed power to the tissue applies the current density of between 0.034 and 0.1 Amperes per square millimeter.
34. The method of claim 28 , wherein:
the tissue being fused comprises internal elastic laminae; and
the non-pulsed power causes the internal elastic laminae to fuse within the period of time.
35. The method of claim 28 , wherein the step of applying the non-pulsed power to the tissue applies the current density of 0.034 Amperes per square millimeter or more.
36. The method of claim 28 , wherein the step of applying the non-pulsed power to the tissue applies the current density of 0.04 Amperes per square millimeter.
37. The method of claim 28 , further comprising delivering the non-pulsed power at a power of 35 Watts or less.
38. The method of claim 28 , wherein the pair of end effectors are adapted to compress the tissue being fused between a gap of greater than 0.0 millimeters and 0.127 millimeters or less.
39. The method of claim 38 , wherein the pair of end effectors are adapted to apply between 448 and 758 kPa of pressure to the tissue being fused.
40. The method of claim 28 , further comprising:
compressing the tissue to a gap of greater than 0.0 millimeters and less than or equal to 0.127 millimeters; and
applying pressure of between 448 and 758 kPa to compress the tissue between the pair of end effectors on the surgical instrument.
41. The surgical system of claim 1 , wherein the surgical system is configured to:
deliver the radio frequency energy to the tissue being fused with the current density of about 0.034 Amperes per square millimeter or more.
42. The surgical system of claim 1 , wherein the surgical system is configured to: deliver the radio frequency energy to the tissue being fused with the current density of about 0.04 Amperes per square millimeter.