US 6,272,373 B1Granted

Scanning system and method for locating sources of radiation emission

AssigneeNeoprobe Corporation

InventorChad E. Bouton

Life of this patent

Estimating the term…

Loading patent…

Abstract

A scanning system for a hand-held probe employs a 50 ms scanning interval in conjunction with circular memory. Combinations of segment bins from the circular memory are acquired following each short scanning interval. A threshold is computed for each combination initially based upon a threshold factor which is statistically significant and has a value of three. Audible cueing is developed if any three of six of these combinations of segment bin scan counts exceeds a correspondingly computed threshold value. Thereafter, the threshold factor is diminished to a value of one and the same thresholding tests are carried out to maintain audible cueing. Running count rates are computed as the average of the entire circular buffer memory divided by its corresponding total collection time. This computation is provided on a one half second updated basis.

Claims31

Dependent claims

A system for detecting and locating sources of radiation at a region of interest evidencing background radiation, comprising:

a probe moveable within said region of interest to provide a scan pulsed output corresponding with said sources and positionable to evaluate said background radiation and derive a background pulsed output corresponding therewith;
an audible indicator responsive to an audio input for providing an audibly perceptive output;
a signal treatment network responsive to validate said scan pulsed output and said background pulsed output to provide respective scan count signal and background count signals;
a background switch actuable to provide a background activation signal;
a control circuit including temporary memory, responsive to said background activation signal and to said background count signals to derive a background count value, BCV, responsive to compile said scan count signals for a sequence of scan intervals to derive a scan interval count value with respect to each scan interval and locate said scan interval count values in said sequence in said temporary memory as memory segment counts, responsive for each said scan interval to access an initial select number of said memory segment counts in predetermined sequential memory segment count combinations, each said combination having a combined count period, T, responsive to said background value, BCV, to a first threshold factor, f1, and said combined count period, T, to compute a first count rate threshold value for each said count combination in correspondence with the expression:
( BCV * T ) + ( f1 ⁢ BCV * T ) T ,
responsive to generate said audio input when a predetermined number of said sequential memory segment count combinations represent a count rate greater than the corresponding said first count rate threshold value, responsive for a next said scan interval when said audio output has been generated to access a next select number of said memory segment counts in predetermined sequential memory segment count combinations, each said combination having a combined count period, T, responsive to said background value, BCV, to a second threshold factor, f2, less than said first threshold factor, f1, and said combined count period to compute a second count rate threshold value for each said count combination in correspondence with the expression:
( BCV * T ) + ( f2 ⁢ BCV * T ) T ,
responsive to generate said audio input when a predetermined number of said sequential memory segment count combinations represent a count rate greater than the corresponding said second count rate threshold value.

6 more elements

A method for detecting and locating sources of radiation at a region of interest evidencing background radiation, comprising:

(a) providing a probe movable within said region of interest;
(b) positioning said probe at said region of interest for a background interval to derive a background pulsed output;
(c) scanning said probe within said region of interest to derive a scanned pulsed output;
(d) providing an audible indicator responsive to an audio input for providing an audibly perceptive output;
(e) providing a signal treatment network responsive to validate said scan pulsed output and said background pulsed output to provide respective scan count signals and background count signals;
(f) providing a control circuit including a circular memory having a predetermined number of memory bins from first to last;
(g) deriving a background count value (BCV), from said background pulsed output;
(h) compiling said scan output signals for a sequence of scan intervals to derive a scan interval count value with respect to each scan interval;
(i) locating each said scan interval count value as a memory segment count in said sequence in sequential said memory bins;
(j) for each compiled said scan interval, accessing a first predetermined number of combinations of said memory bins which include said first bin and the corresponding count period, T, represented by each of said combinations, and computing a first count rate threshold value for each said combination in correspondence with the expression:
( BCV * T ) + ( f1 ⁢ BCV * T ) T ,
where f1 is a first threshold factor;
(k) deriving said audio input when a predetermined first number of said combinations represent a count rate greater than the said first count rate threshold value corresponding therewith;
(l) for the compiled next scan interval following said compiled scan interval of step (j), when said audio input has been derived in step (k), accessing a second predetermined number of combinations of said memory bins and the corresponding count period, T, represented by each of said combinations, and computing a second count rate threshold value for each said combination in correspondence with the expression:
( BCV * T ) + ( f2 ⁢ BCV * T ) T ,
where f2 is a second threshold factor less than said first threshold factor;
and
(m) deriving said audio input when a predetermined second number of said combination derived in step (l) represent a count rate greater than the said second count rate threshold value corresponding therewith.

15 more elements

A system for detecting and locating sources of radiation at a region of interest within an environment evidencing background radiation, comprising:

a probe movable within said region of interest to provide a scan pulsed output corresponding with radiation from said sources and positionable to evaluate said background radiation and derive a background pulsed output corresponding therewith;
an audible indicator responsive to an audio input for providing an audibly perceptive output;
a signal treatment network responsive to validate said scan pulsed output and said background pulsed output to provide respective scan count signal and background count signals;
a background switch actuable to provide a background activation signal;
a control circuit including temporary memory, responsive to said background activation signal and to said background count signals to derive a background value, responsive to compile said scan count signals for a sequence of scan intervals to derive a scan interval count value with respect to each of said scan intervals and locate said scan interval count value in said sequence in said temporary memory as memory segment counts, responsive for each said scan interval to access a select number of said memory segment counts in predetermined memory segment count combinations to derive a corresponding select number of scanned count rate values, responsive to said background value, to a first statistically significant threshold factor and each scan interval represented by said memory segment count combinations to derive a first count rate threshold value for each of said combinations responsive to generate said audio input when a predetermined number of corresponding said combinations represent a count rate greater than a corresponding said first count rate threshold value, then responsive for a next said scan interval when said audio output has been generated, to access a select number of said memory segment counts in predetermined memory segment count combinations to derive a corresponding select number of scanned count rate values, responsive to said background value, to a second statistically significant threshold factor less than said first threshold factor and each scan interval represented by said memory count combinations to derive a second count rate threshold value for each said combination, responsive to generate said audio output when a predetermined number of corresponding said combinations represent a count rate greater than said second count rate threshold value.

2 more elements

Dependencies are inferred from the claim text.