Author: claimsbot

1. A surgical instrument for use in spinal surgery comprising a first portion connected to a second portion; wherein
said first portion and second portion are longitudinally offset from each other;
said first portion is generally D-shaped in transverse cross-section and further comprises a top and bottom surface having rasp teeth;
said first portion further including at least one aperture that extends the entire transverse length of said first portion;
said second portion is generally rectangular shaped and further comprises an access port for guiding a reamer device; and
said second portion is adapted for removable attachment to a holder.
2. The surgical instrument of claim 1, wherein at least one of said first and second portion further comprises at least one contact member.
3. The surgical instrument of claim 2, wherein said at least one contact member is at least one of slidably and rotatably connected to said first portion, said second portion, or combinations thereof.
4. The surgical instrument of claim 2, wherein said at least one contact member is extendable from at least one of said first and second portion.
5. The surgical instrument of claim 1, wherein said at least one first portion further comprises at least one graded marking.
6. The surgical instrument of claim 1, wherein said at least one second portion further comprises at least one graded marking.
7. The surgical instrument of claim 1, wherein said second portion is integrally connected to a holder
8. The surgical instrument of claim 1, wherein said instrument is comprised of a durable material.
9. The surgical instrument of claim 8, wherein the durable material is at least one of a pure metal and metal alloy.
10. The surgical instrument of claim 1, wherein said access port is controllably extendable from said second portion.
11. The surgical instrument of claim 10, wherein said access port is telescoping.
12. The surgical instrument of claim 1, wherein said access port is threaded.
13. A surgical instrument for use in spinal surgery comprising a first portion connected with a second portion; said first portion having top and bottom surfaces wherein at least one of said surfaces comprises rasp teeth; and said second portion including a device guide.
14. The surgical instrument of claim 13, wherein said first portion is removably connectable to said second portion.
15. The surgical instrument of claim 13, wherein said device guide is controllably extendable from said second portion.
16. The surgical instrument of claim 15, wherein said device guide is telescoping.
17. The surgical instrument of claim 13, wherein the device guide is an access port.
18. The surgical instrument of claim 17, wherein said access port is threaded.
19. The surgical instrument of claim 13, wherein the device guide is a frame.
20. The surgical instrument of claim 13, wherein the device guide is a track.
21. The surgical instrument of claim 13, wherein the first portion is generally D-shaped.
22. The surgical instrument of claim 13, further comprising at least one contact member connected to at least one of said first and second portion.
23. The surgical instrument of claim 22, wherein said at least one contact member is at least one of slidably and rotatably connected.
24. The surgical instrument of claim 22, wherein said at least one contact member is extendable from at least one of said first and second portion.
25. The surgical instrument of claim 13, wherein at least one of said first portion and second portion further comprise at least one graded marking.
26. The surgical instrument of claim 13, wherein said first portion is substantially planar.
27. The surgical instrument of claim 13, wherein said first portion is substantially cylindrical.
28. The surgical instrument of claim 13, wherein said first portion and said second portion are longitudinally offset from each other.
29. The surgical instrument of claim 13, wherein said second portion is removably connectable to a holder.
30. The surgical instrument of claim 13, wherein said second portion is integrally connected to a holder.
31. The surgical instrument of claim 13, wherein said first portion further includes at least one aperture that extends the entire transverse length of said first portion.
32. A kit for performing spinal surgery comprising:
a surgical instrument comprising at least one first portion being connectable or connected with at least one second portion; the first portion comprising top and bottom surfaces wherein at least one of said surfaces has rasp teeth; and the second portion including a device guide.
33. The kit of claim 32, wherein said device guide is an access port.
34. The kit of claim 32, wherein said device guide is a frame.
35. The kit of claim 32 wherein said device guide is a track.
36. The kit of claim 32, wherein the first portion is generally D-shaped.
37. The kit of claim 32, further comprising at least one contact member connected to at least one of said first and second portion.
38. The kit of claim 37, wherein said at least one contact member is extendable from at least one of said first and second portion.
39. The kit of claim 37, wherein said at least one contact member is slidably, rotatably, or combinations thereof, connected to at least one of said first and second portion.
40. The kit of claim 32, wherein said at least one first or second portion further includes at least one graded marking.
41. The kit of claim 32, wherein said at least one first portion is substantially planar.
42. The kit of claim 32, wherein said at least one first portion is substantially cylindrical.
43. The kit of claim 32, wherein said at least one first and second portion are longitudinally offset from each other.
44. The kit of claim 32, wherein said at least one second portion is integrally connected to a holder.
45. The kit of claim 32, wherein said at least one first portion further includes at least one aperture that extends the entire transverse length of said first portion.
46. The kit of claim 32, wherein said at least one second portion is removably connectable to a holder.
47. A method of performing spinal surgery comprising the steps of:
providing a surgical instrument comprising a first portion being connected or connectable with a second portion; the first portion including top and bottom surfaces wherein at least one of said surfaces has rasp teeth; the second portion including a device guide;
exposing the spine and identifying the center of at least one target vertebral disc;
removing the anterior annulus of said at least one vertebral disk and performing at least a partial discectomy, thus creating at least one intervertebral cavity;
removing a sufficient amount of spinal endplate cartilage to expose underlying bone;
distracting at least one intervertebral cavity;
using the first portion of said surgical instrument to prepare at least one of the posterior-lateral and anterior-lateral regions of one or more spinal endplates;
providing a reamer through the device guide of the surgical instrument to further prepare said one or more spinal endplates.
48. The method of claim 47, wherein the step of exposing the spine comprises an anterior surgical approach.
49. The method of claim 47, wherein a complete discectomy is performed.
50. The method of claim 47 further comprising the step of impacting at least one successively sized first-portion of the surgical instrument into the intervertebral cavity.
51. The method of claim 47, wherein the step of lateral preparation of one or more spinal endplates, comprises the step of contra-laterally rotating said surgical instrument.
52. The method of claim 47, wherein the step of providing a reamer comprises the steps of providing the reamer under fluoroscopic guidance.
53. The method of claim 47 further comprising the step of placing an appropriately sized implant into the prepared intervertebral cavity.
54. The method of claim 47, wherein said device guide is an access port.
55. The method of claim 47, wherein said device guide is a frame.
56. The method of claim 47, wherein said device guide is a track.
57. The method of claim 47, wherein said first portion is generally D-shaped.
58. The method of claim 47, further comprising at least one contact member connected to at least one of said first and second portion.
59. The method of claim 58, wherein said contact members are at least one of slidably and rotatably connected.
60. The method of claim 58, wherein said at least one contact member is extendable from said at least one of first and second portion.
61. The method of claim 47, wherein said first portion is substantially planar.
62. The method of claim 47, wherein said first portion is substantially cylindrical.
63. The method of claim 47, wherein said second portion is removably connectable to a holder.
64. The method of claim 47, wherein said first portion further includes at least one aperture that extends the entire transverse length of said first portion.
65. The method of claim 47, wherein said device guide is controllably extendable from said second portion.
66. The method of claim 54, wherein said access port is telescoping.
67. The method of claim 54, wherein said access port is threaded.
68. The method of claim 47, wherein said reamer further comprises a collet.
69. The method of claim 47, wherein said reamer is operatively engaged with said device guide.

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 modulating the amount of air supplied through a pressure boundary in a gas turbine, the system comprising:
a passageway located on a pressure boundary in a gas turbine;
a temperature activated valve configured to activate at a predetermined temperature threshold, said temperature activated valve including a housing mounted directly within said passageway, said housing including a first chamber and a second chamber separated from said first chamber; and
wherein said temperature activated valve activates from a closed position to an open position when a local temperature at said temperature activated valve reaches or exceeds said predetermined temperature threshold to allow air to flow through said passageway.
2. The system of claim 1, further comprising a plurality of passageways and a plurality of temperature activated valves, wherein each temperature activated value of said plurality of temperature activated valves is mounted within one of said plurality of passageways.
3. The system of claim 2, wherein said plurality of temperature activated valves comprises a first temperature activated valve and a second temperature activated valve, said first temperature activated valve being configured to activate from a closed position to an open position at a first temperature threshold, said second temperature activated valve being configured to activate from a closed position to an open position at a second temperate threshold, said second temperature threshold being higher than said first temperature threshold.
4. The system of claim 1, wherein said first chamber defines an inlet orifice and at least one outlet port.
5. The system of claim 4, wherein said temperature activated valve further comprises an activation device disposed in said second chamber and a valve stem coupled to the activation device, said valve stem extending from said second chamber to said first chamber, said temperature activated valve further comprising a valve head coupled to said valve stem, said valve head being moved relative to said inlet orifice when said valve stem is activated by said activation device.
6. The system of claim 5, wherein said activation device comprises a pair of bimetallic members or a liquid-filled below.
7. The system of claim 1, wherein said temperature activated valve comprises a valve head configured to be spaced apart from an inlet orifice when said temperature activated valve is in said open position, said temperature activated valve further comprising a locking mechanism configured to lock said temperature activated valve such that said valve head is maintained spaced apart from said inlet orifice even when said local temperature falls below said predetermined temperature threshold.
8. The system of claim 7, wherein said temperature activated valve further comprises a valve stem extending from said valve head, said locking mechanism being configured to engage a protrusion extending from said valve stem in order to lock said temperature activated valve.
9. A system for modulating the amount of air supplied through a pressure boundary in a gas turbine, the system comprising:
a plurality of passageways located on said pressure boundary, said plurality of passageways including a first passageway and a second passageway;
a plurality of temperature activated valves configured to activate at increasing predetermined temperature thresholds, said plurality of temperature activated valves including a first temperature activated valve mounted within said first passageway and a second temperature activated valve mounted within said second passageway, said first temperature activated valve being configured to activate from a closed position to an open position at a first temperature threshold, said second temperature activated valve being configured to activate from a closed position to an open position at a second temperature threshold,
wherein said second temperature threshold is higher than said first temperature threshold.
10. The system of claim 9, wherein said pressure boundary is located axially forward of a turbine section of said gas turbine.
11. The system of claim 9, wherein said first temperature activated valve comprises a housing mounted directly within said first passageway.
12. The system of claim 11, wherein said housing includes a first chamber and a second chamber, said first chamber being separated from said second chamber.
13. The system of claim 12, wherein said first chamber defines an inlet orifice and at least one outlet port.
14. The system of claim 13, wherein said first temperature activated valve further comprises an activation device disposed in said second chamber and a valve stem coupled to said activation device, said valve stem extending from said second chamber to said first chamber, said first temperature activated valve further comprising a valve head coupled to said valve stem, said valve head being moved relative to said inlet orifice when said valve stem is activated by the activation device.
15. The system of claim 14, wherein said activation device comprises a pair of bimetallic members or a liquid-filled below.
16. The system of claim 9, wherein said first temperature activated valve comprises a valve head configured to be spaced apart from an inlet orifice when said first second temperature activated valve is in said open position, said first temperature activated valve further comprising a locking mechanism configured to lock said first temperature activated valve such that said valve head is maintained spaced apart from said inlet orifice even when said local temperature falls below said first temperature threshold.
17. The system of claim 16, wherein said first temperature activated valve further comprises a valve stem extending from said valve head, said locking mechanism being configured to engage a protrusion extending from said valve stem in order to lock said temperature activated valve.
18. The system of claim 9, wherein said first temperature activated valve comprises a first inlet orifice and said second temperature activated valve comprises a second inlet orifice, wherein said first inlet orifice differs in size from said second inlet orifice.
19. A system for modulating the amount of air supplied through a pressure boundary in a gas turbine, the system comprising:
a passageway located on a pressure boundary in a gas turbine, said pressure boundary being located axially forward of a first stage bucket of the gas turbine;
a temperature activated valve configured to activate at a predetermined temperature threshold, said temperature activated valve including a housing mounted directly within said passageway; and
wherein said temperature activated valve activates from a closed position to an open position when a local temperature at said temperature activated valve reaches or exceeds said predetermined temperature threshold to allow air to flow through said passageway.

1. A method, a sensor array that employs a parameter to induce a time-varying phase angle \u03c6 on an optical signal that comprises a phase generated carrier, the method comprising the steps of:
calculating a quadrature term Q through employment of one or more of a plurality of samples that are based on the optical signal;
calculating a peak value Qp of the quadrature term Q;
calculating an in-phase term I through employment of one or more of the plurality of samples that are based on the optical signal;
calculating a peak value In of the in-phase term I;
I
p

\u2061

(

M
,
\u03b2

)
=

2
\xb7
B
\xb7
(
cos
\u2061

(
M
\xb7
sin

\u2062

\u2003

\u2062
\u03b2

)
–

cos
\u2061

(

M
\xb7

sin
\u2061

(
\u03c0
2

+
\u03b2

)
)
)

.
wherein M is a modulation depth and \u03b2 is a demodulation phase offset of the phase generated carrier;
calculating an operating point that comprises the modulation depth M and the demodulation phase offset \u03b2 of the phase generated carrier through employment of the peak value Ip of the in-phase term I and the peak value Qp of the quadrature term Q; and
calculating the phase angle \u03c6 through employment of the quadrature term Q; and the in-phase term, wherein the quadrature term Q and the in-phase term I are based on the optical signal.
2. The method of claim 1, wherein the step of calculating the phase angle \u03c6 through employment of the in-phase term I and the quadrature term Q comprises the step of:
calculating the phase angle \u03c6 through employment of the in-phase term I and the quadrature term Q at the operating point.
3. The method of claim 1, wherein the step of calculating the chase angle \u03c6 through employment of the in-phase term I and the quadrature term Q comprises the step of:
calculating the phase angle \u03c6=arctangent(QI).
4. The method of claim 1, wherein the phase generated carrier comprises a period Tpgc, the method further comprising the step of:
sampling an output signal from the sensor array to obtain the plurality of samples from a same instance of the period Tpgc.
5. The method of claim 4, wherein the plurality of samples comprise samples S0, S1, S2, and S3, wherein the step of calculating the in-phase term I through employment of the one or more of the plurality of samples comprises the step of:
calculating the in-phase term I:
I=(S0+S2)\u2212(S1+S3).
6. The method of claim 5, wherein the step of calculating the quadrature term Q through employment of one or more of the plurality of samples that are based on the optical signal comprises the step of:
calculating the quadrature term Q:
Q=2*(S0\u2212S2):
wherein the step of calculating the peak value Qp of the quadrature term Q comprises the step of:
calculating the peak value Qp of the quadrature term Q:
Qp(M, \u03b2)=4\xb7B\xb7sin(M\xb7sin \u03b2).
7. The method of claim 5, wherein the step of calculating the quadrature term Q through employment of one or more of the plurality of samples that are based on the optical signal comprises the step of:
calculating the quadrature term Q:
Q=\u2212(S0\u2212S2):
wherein the step of calculating the peak value Q2 of the quadrature term Q comprises the step of:
calculating the peak value Qp of the quadrature term Q:
Qp(M, \u03b2)=2\xb7B\xb7sin(M\xb7\u03b2).
8. A method, a sensor array that employs a parameter to induce a time-varying phase angle \u03c6 on an optical signal that comprises a phase generated carrier, wherein the phase generated carrier comprises a period Tpgc, the method comprising the steps of:
calculating the phase angle \u03c6 through employment of a quadrature term Q and an in-phase term I, wherein the quadrature term Q and the in-phase term I are based on the optical signal;
wherein the phase generated carrier comprises a period Tpgc, the method further comprising the step of:
sampling an output signal from the sensor array to obtain the plurality of samples from a same instance of the period Tpgc;
wherein the step of calculating the phase angle \u03c6 through employment of the quadrature term Q and the in-phase term I comprises the steps of:
calculating the in-phase term I through employment of one or more of the plurality of samples;
calculating a quadrature term Q through employment of one or more of the plurality of samples; and
calculating the phase angle \u03c6 through employment of the in-phase term I and the quadrature term Q;
further comprising the steps of:
calculating a peak value Ip of the in-phase term I;
calculating a peak value Qp of the quadrature term Q; and
calculating an operating point that comprises a modulation depth M and a demodulation phase offset \u03b2 of the phase generated carrier through employment of the peak value Ip of the in-phase term I and the peak value Qp of the quadrature term Q;
wherein the plurality of samples comprise samples S0, S1, S2, and S3, wherein the step of calculating the in-phase term I through Qp employment of the one or more of the plurality of samples comprises the step of:
calculating the in-phase term I:
I=(S0+S2)\u2212(S1+S3);
wherein the step of calculating the peak value Ip of the in-phase term I comprises the step of:
calculating the peak value Ip of the in-phase term I:
I
p

\u2061

(

M
,
\u03b2

)
=

2
\xb7
B
\xb7
(
cos
\u2061

(
M
\xb7
sin

\u2062

\u2003

\u2062
\u03b2

)
–

cos
\u2061

(

M
\xb7

sin
\u2061

(
\u03c0
2

+
\u03b2

)
)
)

.
9. The method of claim 8, wherein the step of calculating the quadrature term Q through employment of the one or more of the plurality of samples comprises the step of:
calculating the quadrature term Q:
Q=\u2212(S0\u2212S2).
10. The method of claim 9, wherein the step of calculating the peak value Qp of the quadrature term Q comprises the step of:
calculating the peak value Qp of the quadrature term Q:
Qp(M, \u03b2)=2\xb7B\xb7sin(M\xb7sin \u03b2).
11. The method of claim 10, wherein the step of calculating the phase angle \u03c6 through employment of the in-phase term I and the quadrature term Q comprises the step of:
calculating the phase angle \u03c6 arctangent(QI).
12. The method of claim 8, wherein the step of calculating the quadrature term Q through employment of the one or more of the plurality of samples comprises the step of:
calculating the quadrature term Q:
Q=\u22122*(S0\u2212S2).
13. The method of claim 12, wherein the step of calculating the peak value Qp of the quadrature term Q comprises the step of:
calculating the peak value Qp:
Qp(M, \u03b2)=4\xb7B\xb7sin(M\xb7sin \u03b2).
14. The method of claim 13, wherein the step of calculating the phase angle \u03c6 through employment of the in-phase term I and the quadrature term Q comprises the step of:
calculating the phase angle \u03c6=arctangent(QI).
15. An apparatus, a sensor array that employs a parameter to induce a time-varying phase angle \u03c6 on an optical signal that comprises a phase generated carrier, the apparatus comprising:
a processor component;
wherein the processor component employs one or more of a plurality of samples that are based on the optical signal to calculate an in-phase term I;
wherein the processor component employs one or more of the plurality of samples to calculate a quadrature term Q;
wherein the processor component calculates a peak value Ip of the in-phase term I as
I
p

\u2061

(

M
,
\u03b2

)
=

2
\xb7
B
\xb7

(
cos
\u2061

(
M
\xb7
sin

\u2062

\u2003

\u2062
\u03b2

)
–

cos
\u2061

(

M
\xb7

sin
\u2061

(
\u03c0

2

+
\u03b2

)
)
)
;
wherein M is a modulation depth and \u03b2 is a demodulation phase offset of the phase generated carrier;
wherein the processor component calculates a peak value Qp of the quadrature term Q;
wherein the processor calculates an operating point that comprises the modulation depth M and the demodulation phase offset \u03b2 of the phase generated carrier through employment of the peak value Ip of the in-phase term I and the peak value Qp of the quadrature term Q;
wherein the processor component employs the quadrature term Q and the in-phase term I to calculate the phase angle \u03c6, wherein the quadrature term Q and the in-phase term I are based on the optical signal.
16. The apparatus of claim 15, wherein the phase generated carrier comprises a period Tpgc, wherein the processor component obtains the plurality of samples from an output signal from the sensor array within a same instance of the period Tpgc.
17. The apparatus of claim 16,
wherein the processor component employs the in-phase term I and the quadrature term Q to calculate the phase angle \u03c6 at the operating point.
18. The apparatus of claim 16,
wherein the plurality of samples comprises four samples that are based on the optical signal;
wherein the processor component obtains the four samples from the output signal from the sensor array within the same instance of the period Tpgc.
19. The apparatus of claim 16, wherein the plurality of samples comprise samples S0, S1, S2, and S3;
wherein the processor component calculates the in-phase term I:
I=(S0+S2)\u2212(S1+S3);
wherein the processor component calculates the quadrature term Q:
Q=\u2212(S0\u2212S2);
wherein the processor component calculates the phase angle \u03c6:
\u03c6=arctangent(QI).
20. The apparatus of claim 19,
wherein the processor component calculates the peak value Qp:
Qp(M, \u03b2)=2\xb7B\xb7sin(M\xb7sin \u03b2)
21. The apparatus of claim 20, wherein the processor component employs the peak value Ip and the peak value Qp to calculate the operating point that comprises a modulation depth approximately equal to 2.75 radians.
22. The apparatus of claim 21, wherein the processor component employs the peak value Ip and the peak value Qp to calculate the operating point that comprises a demodulation phase offset approximately equal to 0.5073 radians.
23. The apparatus of claim 16, wherein the plurality of samples comprise samples S0, S1, S2, and S3;
wherein the processor component calculates the in-phase term I:
I=(S0+S2)\u2212(S1+S3);
wherein the processor component calculates the quadrature term Q:
Q=\u22122\xb7(S0\u2212S2);
wherein the processor component calculates the phase angle \u03c6:
\u03c6=arctangent (QI).
24. The apparatus of claim 23,
wherein the processor component calculates the peak value Qp:
Qp(M, \u03b2)=4\xb7B\xb7sin(M\xb7sin \u03b2).
25. The apparatus of claim 24, wherein the processor component employs the peak value Ip and the peak value Qp to calculate the operating point that comprises a modulation depth approximately equal to 2.49 radians.
26. The apparatus of claim 25 wherein the processor component employs the peak value Ip and the peak value Qp to calculate the operating point that comprises a demodulation phase offset approximately equal to 0.3218 radians.
27. An article, a sensor array that employs a parameter to induce a time-varying phase angle \u03c6 on an optical signal that comprises a phase generated carrier, the article comprising:
one or more computer-readable signal-bearing media;
means in the one or more media for calculating a quadrature term Q through employment of one or more of the plurality of samples that are based on the optical signal;
means in the one or more media for calculating an in-phase term I through employment of one or more of a plurality of samples that are based on the optical signal;
means in the one or more media for calculating a peak value Ip of the in-phase term I as
I
p

\u2061

(

M
,
\u03b2

)
=

2
\xb7
B
\xb7

(
cos
\u2061

(
M
\xb7
sin

\u2062

\u2003

\u2062
\u03b2

)
–

cos
\u2061

(

M
\xb7

sin
\u2061

(
\u03c0
2

+
\u03b2

)
)
)
,
wherein M is a modulation depth and \u03b2 is a demodulation phase offset of the phase generated carrier;
means in the one or more media for calculating peak value Qp of the quadrature term Q;
means in the one or more media for calculating an operating point that comprises the modulation depth M and the demodulation phase offset \u03b2 of the phase generated carrier through employment of the peak value Ip of the in-phase term I and the peak value Qp of the quadrature term Q; and
means in the one or more media for calculating the phase angle \u03c6 through employment of the quadrature term Q and the in-phase term I, wherein the quadrature term Q and the in-phase term I are based on the optical signal.
28. The article of claim 27, wherein the plurality of samples comprise samples S0, S1, S2, and S3, wherein the means in the one or more media for calculating the quadrature term Q through employment of the one or more of the plurality of samples that are based on the optical signal comprises:
means in the one or more media for calculating the quadrature term Q:
Q=\u2212(S0\u2212S2);
wherein the means in the one or more media for calculating the peak value Qp of the quadrature term Q comprises:
means in the one or more media for calculating the peak value Qp of the quadrature term Q:
Qp(M, \u03b2)=2\xb7B\xb7sin(M\xb7sin \u03b2).
29. The article of claim 28, wherein the plurality of samples comprise samples S0, S1, S2, and S3, wherein the means in the one or more media for calculating the quadrature term Q through employment of the one or more of the plurality of samples that are based on the optical signal comprises:
means in the one or more media for calculating the quadrature term Q:
Q=\u22122*(S0\u2212S2);
wherein the means in the one or more media for calculating the peak value Qp of the quadrature term Q comprises:
means in the one or more media for calculating the peak value Qp of the quadrature term Q:
Qp(M, \u03b2)=4\xb7B\xb7sin(M\xb7sin \u03b2).
30. The article of claim 27, wherein the means in the one or more media for calculating the phase angle \u03c6 through employment of the in-phase term I and the quadrature term Q comprises:
means in the one or more media for calculating the phase angle \u03c6=arctangent(QI) at the operating point.
31. The method of claim 4, wherein the step of sampling the output signal from the sensor array to obtain the plurality of samples from the same instance of the period Tpgc comprises the step of:
sampling the output signal from the sensor array to obtain four samples from the same instance of the period Tpgc.
32. The method of claim 8, wherein the step of sampling the output signal from the sensor array to obtain the plurality of samples from the same instance of the period Tpgc comprise the step of:
sampling the output signal from the sensor array to obtain four samples from the same instance of the period Tpgc.

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 collapsible ladder for supporting an elevated hunting platform, the collapsible ladder comprising:
a plurality of telescopically engaging collapsible ladder segments each comprising a first ladder rail, a second ladder rail, and a plurality of rung members pivotally attached to each of the first and second ladder rails in a parallelogram linkage, such that a separation between the first and second ladder rails is adjustable between a collapsed position to an expanded position; and
at least one rigid ladder segment comprising a stabilizing member including at least one rung member rigidly attached to a pair of rail sections attached to at least one of the collapsible ladder segments, the pair of rail sections on the at least one rigid ladder segment are telescopically attached to, and co-linear with, the first and second ladder rails on the collapsible ladder segment to maintain the first and second ladder rails in the expanded position.
2. The collapsible ladder of claim 1 comprising a plurality of spring lock pins retaining the stabilizing member in telescopic engagement with the first and second ladder rails.
3. The collapsible ladder of claim 1 wherein a collapsible ladder segment telescopically engages with the elevated hunting platform and the elevated hunting platform maintains the first and second ladder rails in the expanded position.
4. The collapsible ladder of claim 1 wherein the first and second ladder rails are one of the same or different lengths.
5. The collapsible ladder of claim 1 wherein adjacent ends of the first and second rails are staggered in the expanded position.
6. The collapsible ladder of claim 1 wherein the rung members are attached adjacent to respective exterior surfaces of the first and second ladder rails.
7. The collapsible ladder of claim 1 wherein the rigid ladder segment includes two rung members.
8. The collapsible ladder of claim 1 wherein the first and second ladder rails are approximately the same length and wherein the rung members are pivotally attached to the first and second ladder rails at different respective points along the lengths thereof so adjacent ends of the first and second rails are staggered.
9. The collapsible ladder of claim 1 wherein the rail sections on the stabilizing member are different lengths.
10. The collapsible ladder of claim 1 comprising a removable rail segment releasably attachable to a rail section of the stabilizing member.
11. An elevated hunting stand comprising:
a platform assembly;
a ladder assembly comprising a first ladder rail, a second ladder rail, and a plurality of rung member pivotally attached to each of the first and second ladder rails in a parallelogram linkage, such that a separation between the first and second ladder rails is adjustable between a collapsed position to an expanded position, the platform assembly attaches to adjacent ends of the first and second ladder rails at a first end of the ladder assembly to maintain the first and second ladder rails in the expanded position; and
a rigid ladder segment comprising a stabilizing member having at least one rung member rigidly attached to a pair of rail sections that are telescopically attached to, and co-linear with, the first and second ladder rails at a second end of the ladder assembly to maintain the first and second ladder rails in the expanded position.
12. The elevated hunting stand of claim 11 comprising a plurality of stabilizing members attached to the ladder assembly to substantially fix a separation between the first and second rails.
13. The elevated hunting stand of claim 11 wherein the ladder assembly includes a plurality of ladder sections.
14. A method of assembling an elevated hunting stand comprising the steps of:
converting a first ladder assembly from a collapsed position to an expanded position by separating first and second ladder rails connected by a plurality of pivotally attached rung members in a parallelogram linkage; and
attaching adjacent ends of the first and second rails to a platform assembly to maintain the first and second ladder rails in the expanded position; and
attaching a rigid ladder segment comprising a stabilizing member having at least one rung member rigidly attached a pair of rail sections, to a second end of the first ladder assembly so the first and second ladder rails are telescopically attached to, and co-linear with, the pair of rail sections to maintain the first and second ladder rails in the expanded position.
15. The method of claim 14 comprising telescopically engaging the first and second ladder rails to the platform assembly.
16. The method of claim 14 comprising the steps of:
converting a second ladder assembly from a collapsed position to an expanded position;
telescopically engaging the second ladder assembly to the first ladder assembly; and
attaching the rigid ladder segment to a second end of the second ladder assembly.
17. The method of claim 14 comprising the steps of attaching rail sections rigidly attached to a rung member of a stabilizing member to the second ladder assembly, to maintain the first and second ladder rails in the expanded position.