1. A level discrimination circuit comprising:
(a) a first offset compensation circuit including:
a first peak detection circuit detecting a first peak value of a first signal;
a first summing circuit generating a first sum value according to the first peak value and a second signal;
a second peak detection circuit detecting a second peak value of the second signal; and
a second summing circuit generating a second sum value according to the second peak value and the first signal; and
(b) a second offset compensation circuit including:
a third peak detection circuit detecting a third peak value of the second sum value;
a third summing circuit generating a third sum value according to the third peak value and the first sum value;
a fourth peak detection circuit detecting a fourth peak value of the second sum value; and
a fourth summing circuit generating a fourth sum value according to the fourth peak value and the first sum value; and
(c) a comparator generating an output signal according to the third and the fourth sum values.
2. A level discrimination circuit comprising:
a first offset compensation circuit receiving a differential pair of signals A1, NA1, detecting respective peak values AP1, NAP1 therein, adding signal A1 to the detected peak value NAP1 of signal NA1 to generate a first offset-compensated signal B1, and adding signal NA1 to the detected peak value AP1 of signal A1 to generate a second offset-compensated signal NB1; and
a second offset compensation circuit receiving the signals B1 and NB1, detecting respective peak values BP1, NBP1 therein, adding signal B1 to the detected peak value NBP1 of signal NB1 to generate a third offset-compensated signal B2, and adding signal NB1 to the detected peak value BP1 of signal B1 to generate a fourth offset-compensated signal NB2;
further comprising a comparator comparing said signals B2 and NB2 and generating a positive-phase data output signal OUT and a negative-phase data output signal NOUT;
wherein the level discrimination circuit receives an optical signal in bursts, further comprising:
an envelope signal generating circuit for detecting the start of a burst of the optical signal and generating an envelope signal having a duration responsive to a length of said burst, starting when the start of said burst is detected;
a fixed signal generating circuit generating a fixed signal having a level representing non-reception of the optical signal; and
a selector circuit selecting at least one of the positive-phase data output signal OUT and the negative-phase data output signal NOUT when the envelope signal is present, and selecting the fixed signal when the envelope signal is absent.
3. The level discrimination circuit of claim 2, wherein the envelope signal generating circuit comprises a counter receiving a reference clock signal, the counter starting to count when the start of the burst of the optical signal is detected, the envelope signal being terminated when the counter reaches a predetermined value.
4. The level discrimination circuit of claim 3, wherein the counter is reset by one of the signals selected by the selector circuit, and continues to count after being reset.
5. The level discrimination circuit of claim 2, wherein the envelope signal generating circuit comprises a peak detection circuit for detecting a peak level of one of the signals selected by the selector circuit, and a circuit for terminating the envelope signal when the detected peak level falls below a predetermined level.
6. A method of discriminating logic levels of a differential pair of signals A1, NA1, comprising:
detecting a peak value AP1 of signal A1;
detecting a peak value NAP1 of signal NA1;
adding said signal A1 to the detected peak value NAP1 of said signal NA1 to generate a signal B1;
adding said signal NA1 to the detected peak value AP1 of said signal A1 to generate a signal NB1;
detecting a peak value BP1 of said signal B1;
detecting a peak value NBP1 of said signal NB1;
generating a signal B2 by adding said signal B1 to the detected peak value NBP1 of said signal NB1; and
generating a signal NB2 by adding said signal NB1 to the detected peak value BP1 of said signal B1.
7. The method of claim 6, wherein:
generating said signal B2 also includes subtracting said peak value NBP1, so that said signal B2 is referenced to said peak value NBP1; and
generating said signal NB2 also includes subtracting said peak value BP1, so that said signal NB2 is referenced to said peak value BP1.
8. The method of claim 6, wherein:
generating said signal B2 also includes subtracting said peak value NBP1, so that said signal B2 is referenced to said peak value, NBP1; and
generating said signal NB2 also includes subtracting said peak value BP1, so that said signal NB2 is referenced to said peak value, BP1.
9. The method of claim 6, further comprising comparing said signal B2 with said signal NB2 and thereby generating a positive-phase data output signal OUT and a negative-phase data output signal NOUT.
10. The method of claim 9, further comprising:
generating said signal A1 and said signal NA1 from an optical signal received in bursts;
detecting the start of a burst of the optical signal;
generating an envelope signal having a duration responsive to a length of said burst;
generating a fixed signal having a level representing non-reception of the optical signal;
selecting at least one of said positive-phase data output signal OUT and said negative-phase data output signal NOUT while the envelope signal is present; and
selecting the fixed signal while the envelope signal is absent.
11. The method of claim 10, wherein generating the envelope signal further comprises counting a reference clock signal, the count starting when the start of the burst of the optical signal is detected, and terminating the envelope signal when the count reaches a predetermined value.
12. The method of claim 11, wherein generating the envelope signal further comprises restarting the count responsive to said at least one of said positive-phase data output signal OUT and said negative-phase data output signal NOUT.
13. The method of claim 10, wherein generating the envelope signal further comprises detecting a peak level of said at least one of said positive-phase data output signal OUT and said negative-phase data output signal NOUT, and terminating the envelope signal when the detected peak level falls below a predetermined level.
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 method of closing an opening in a blood vessel, the method comprising:
inserting a closure device at least partially through the opening and into the blood vessel, the closure device including a delivery tube, an actuator, and a closure element, the closure element comprising a body having a proximal portion, a distal portion, and a waist portion, a distal end of the delivery tube being configured with a bias and applies a radial compressive force to the closure element;
reconfiguring the distal portion of the closure element from a pre-deployed configuration to a deployed configuration, by pulling a distal end of the closure element in a proximal direction, while maintaining the proximal portion of the closure device in a pre-deployed configuration, wherein in the deployed configuration, one or more extensions of the distal portion protrude outward from the body beyond an outer edge of the opening in the blood vessel;
engaging an inside portion of the blood vessel distally from the opening in the blood vessel with the distal portion of the closure device by moving the closure device in a proximal direction;
following engaging the inside portion of the opening in the blood vessel, deploying the proximal portion of the closure element from the delivery tube;
reconfiguring the proximal portion of the closure element from the pre-deployed configuration to a deployed configuration by collapsing a collapsible portion of the body in an outward direction, wherein in the deployed configuration, one or more extensions of the proximal portion protrude outward from the body to engage an outside portion of the blood vessel proximally from the opening in the blood vessel; and
locking the proximal portion and the distal portion of the closure element in the deployed configuration by advancing a locking element formed on the actuator through a lumen of the proximal portion.
2. The method recited in claim 1, wherein the locking element is tapered from a proximal end to a distal end.
3. The method according to claim 1, further comprising deploying a hemostatic material on or adjacent to the opening in the blood vessel.
4. The method recited in claim 1, further comprising disengaging the delivery tube and actuator from the closure element and removing the delivery tube and actuator.
5. The method recited in claim 1, further comprising holding the proximal end of the closure device between the locking element and a coupler element, the coupler element being coupled to or incorporated with the actuator.
6. The method recited in claim 1, further comprising severing the actuator proximally to the locking element.
7. The method recited in claim 1, wherein reconfiguring the proximal portion of the closure element from the pre-deployed configuration to the deployed configuration further comprises:
compressively restraining the proximal portion of the closure device within the delivery tube, thereby preventing the collapsible portion of the body from collapsing in the outward direction after the locking element is pulled out of the proximal portion of the closure device; and
releasing the proximal portion of the closure device from the delivery tube, thereby collapsing the collapsible portion of the body and reconfiguring the proximal portion of the closure device to the deployed configuration.
8. The method of claim 1, further comprising positioning the closure device at a predetermined depth within the delivery tube with at least a portion of the closure device extending beyond the distal end of the delivery tube.
9. The method of claim 8, wherein the predetermined depth is set by a protrusion that limits the insertion of the closure device within the delivery tube.
10. A method of closing an opening in a blood vessel, the method comprising:
inserting a closure device at least partially through the opening, the closure device including a delivery tube, an actuator, and a closure element, the closure element comprising a body having a proximal portion, a distal portion, and a waist portion, a portion of the distal portion of the closure element extending distally from a delivery tube distalmost end prior to inserting the closure device at least partially through the opening, and the proximal portion of the closure element being disposed, within the delivery tube prior to inserting the closure device at least partially through the opening, adjacent a blocking protrusion disposed within a lumen of the delivery tube that prevents proximal movement of the closure device within the lumen of the delivery tube;
reconfiguring the distal portion of the closure element from a pre-deployed configuration to a deployed configuration, by pulling the distal end of the closure element in a proximal direction, while maintaining the proximal portion of the closure device in a pre-deployed configuration, wherein in the deployed configuration, one or more extensions of the distal portion protrude outward from the body;
engaging the inside portion of the opening in the blood vessel with the distal portion of the closure device by moving the closure device in a proximal direction; and
reconfiguring the proximal portion of the closure element from the pre-deployed configuration to a deployed configuration by collapsing a collapsible portion of the body in an outward direction, wherein in the deployed configuration, one or more extensions of the proximal portion protrude outward from the body.
11. The method recited in claim 10, further comprising locking the distal portion and the proximal portion of the closure element in their respective deployed configurations.
12. The method according to claim 10, further comprising deploying a hemostatic material on or adjacent to the opening in the blood vessel.
13. The method recited in claim 10, further comprising disengaging the delivery tube and actuator from the closure element and removing the delivery tube and actuator.
14. The method recited in claim 10, wherein collapsing a portion of the body comprises pulling a locking element through and out of the proximal portion of the closure device, the locking element being coupled to or incorporated with the actuator and being configured to collapse the collapsible portion of the body in the outward direction.
15. The method recited in claim 14, further comprising holding the proximal end of the closure device between the locking element and a coupler element, the coupler element being coupled to or incorporated with the actuator.
16. The method recited in claim 14, further comprising severing the actuator proximally to the locking element.
17. The method recited in claim 14, wherein reconfiguring the proximal portion of the closure element from the pre-deployed configuration to the deployed configuration further comprises:
compressively restraining the proximal portion of the closure device within the delivery tube, thereby preventing the collapsible portion of the body from collapsing in the outward direction after the locking element is pulled out of the proximal portion of the closure device; and
releasing the proximal portion of the closure device from the delivery tube, thereby collapsing the collapsible portion of the body and reconfiguring the proximal portion of the closure device to the deployed configuration.
18. The method of claim 10, further comprising positioning the closure device at a predetermined depth within the delivery tube.
19. The method of claim 18, wherein the predetermined depth is set by a protrusion that limits the insertion of the closure device within the delivery tube.