1. An X-ray spectrometer comprising:
an X-ray detector for detecting X-rays and outputting a staircase waveform having steps whose heights correspond to energy levels of the X-rays;
a first differential filter having a time constant and operative to convert the staircase waveform into a first pulsed signal having peaks whose heights correspond to the heights of the steps;
an event detection portion for making a decision as to whether the first pulsed signal has exceeded a threshold value;
a noise event detection portion for making a decision as to whether a period during which the first pulsed signal is in excess of the threshold value is shorter than a given time;
a second differential filter having a time constant longer than the time constant of the first differential filter and operative to convert the staircase waveform into a second pulsed signal having peaks whose heights correspond to the heights of the steps;
a maximum value detection portion which, if the first pulsed signal is judged to be in excess of the threshold value, starts to detect a maximum value of the second pulsed signal; and
a decision portion for making a decision as to whether information about the maximum value is output, based on the decision made by the noise event detection portion.
2. An X-ray spectrometer comprising:
an X-ray detector for detecting X-rays and outputting a staircase waveform having steps whose heights correspond to energy levels of the X-rays;
a first differential filter having a time constant and operative to convert the staircase waveform into a first pulsed signal having peaks whose heights correspond to the heights of the steps;
an event detection portion for making a decision as to whether the first pulsed signal has exceeded a first threshold value;
a noise event detection portion for making a decision as to whether said first pulsed signal is below a second threshold value;
a second differential filter having a time constant longer than the time constant of the first differential filter and operative to convert the staircase waveform into a second pulsed signal having peaks whose heights correspond to the heights of the steps;
a maximum value detection portion which, if the first pulsed signal is judged to be in excess of the first threshold value, starts to detect a maximum value of the second pulsed signal; and
a decision portion for making a decision as to whether information about the maximum value is output, based on the decision made by the noise event detection portion.
3. An X-ray spectrometer as set forth in claim 2,
wherein said peaks of the first pulsed signal appear on a positive side of a reference level;
wherein said first threshold value is set on the positive side; and
wherein said second threshold value is set on a negative side of the reference level.
4. A sample analyzer including an X-ray spectrometer as set forth in any one of claims 1 to 3.
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 computer program product for use in connection with a localization device for removing a wedge from a bone during a surgical procedure so as to achieve a predetermined desired correction angle between joints at opposing ends of said bone, said edge being formed by first and second cuts in the bone that intersect at a pivot location, said computer program product comprising:
computer readable program code embodied in a non-transitory computer readable medium, the computer readable program code comprising at least:
computer readable program code for recording a depth and angle of said first cut observed by the localization device during the surgical procedure;
computer readable program code for determining the pivot location during the surgical procedure using the recorded depth and angle of the first cut; and
computer readable program code for calculating an angle of said second cut during the surgical procedure using (i) the determined pivot location, (ii) said recorded angle of said first cut, and (iii) said predetermined desired correction angle.
2. The computer program product of claim 1, wherein said localization device provides information identifying a first position corresponding to a first end of said bone and a second position corresponding to a second end of said bone prior to removing the wedge and wherein, after removing the wedge, said second end of said bone is relocated to a third position such that the desired correction angle is produced between a first vector extending from the first position to the second position and a second vector extending from the first position to the third position.
3. The product of claim 2, wherein said computer readable program code for calculating said angle of said second cut comprises at least computer readable program code for solving the equation:
\u03b2
=
cos
–
1
\u2061
(
(
PA
\u2062
\u2062
PA
\u2032
)
\uf605
PA
\uf606
\u2062
\uf605
PA
\u2032
\uf606
)
where \u03b2 is said angle of said second cut, PA is a vector extending from said pivot location to the second position, and PA\u2032 is a vector extending from said pivot location to the third position.
4. The product of claim 2, wherein said computer readable program code further comprises at least:
computer readable program code for determining:
A\u2032=K+KA cos(\u03b1)+KAortho sin(\u03b1);
where A\u2032 is the third position, K is the first position, KA is a vector extending from the first position to the second position, KAortho is a vector of equal magnitude and orthogonal to KA, and \u03b1 is the desired correction angle.
5. The product of claim 4, wherein said computer readable program code for calculating said angle of said second cut comprises at least computer readable program code for solving the equation:
\u03b2
=
cos
–
1
\u2061
(
(
PA
\u2062
\u2062
PA
\u2032
)
\uf605
PA
\uf606
\u2062
\uf605
PA
\u2032
\uf606
)
;
where \u03b2 is said angle of said second cut, PA is a vector extending from said pivot location to the second position, and PA\u2032 is a vector extending from said pivot location to the third position.
6. The computer program product of claim 2, wherein the computer readable program code for recording a depth and angle of the first cut comprises: computer readable code for determining an axis of said bone using the localization device; and computer readable code for guiding a cutting jig for making the first cut relative to the bone using the localization device.
7. The computer program product of claim 6, wherein the computer readable program code for recording the angle and depth of the first cut further comprises:
computer readable code for generating a display showing the axis and the position of the cutting jig relative to the axis.
8. The computer program product of claim 7, further comprising: computer readable code for tracking a pointer relative to the bone;
and computer readable code for generating a display showing the wedge angle that would result if the second cut were commenced at the location of the pointer and ended at the pivot location.