System and apparatus for detecting and locating sources of radiation

• US 6,259,095 B1
• Filed: 10/23/1998
• Issued: 07/10/2001
• Est. Priority Date: 10/23/1998
• Status: Expired due to Term

• Current Assignee: Devicor Medical Products Incorporated (Danaher Corporation)
• Original Assignee: Neoprobe Corporation
• Inventors: Kramer, Daniel A., Mayoras, Richard C. Jr., Bouton, Chad E.
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Israel, Andrew
• Application Number:
  US09/178,322
• Time in Patent Office: 991 Days
• Field of Search: 250/336.1, 250/370.06, 250/369
• US Class Current: 250/336.1
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/4423 related to hygiene or sterilisation
• CPC Class Codes: A61B 6/462 characterised by constructional features of the display
• CPC Class Codes: A61B 6/463 characterised by displaying multiple images or images and diagnostic data on one display
• CPC Class Codes: A61B 6/469 for selecting a region of interest [ROI]
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography

Abstract

System and apparatus for locating sources of radiation emanating from predetermined radionuclides. The apparatus incorporates a large window display utilizing icon imagery to identify counting functions such as target count and background. A variety of radionuclide modes of operation can be selected by the operator and the system automatically defaults to detector bias selection and window reference voltage selection in correspondence with the elected radionuclide. A bar graph readout apprises the user of the amount of time or count level remaining in a target or background procedure and the flashing of icon identifiers occurs during such procedures. Pulse validation is improved by the utilization of a discriminator which evaluates pulse width.

Claims

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

a probe moveable within said region of interest and having a pulsed output corresponding with radiation from said source;

a control assembly having a perceptible output including a display responsive to a first count rate value signal to provide a first perceptible count rate output, responsive to a second count rate value signal to provide a second perceptible count rate output, responsive to a third count rate value signal to provide a third perceptible count rate output, responsive to a graph signal to provide a perceptible bar graph output with segments energizable from first to last, and said control assembly supporting a target count switch actuable to derive first and second target count signals;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal and a first predetermined interval to derive said first count rate value signal, responsive to said first target count signal and a second interval to derive said second count rate value signal, and for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said second count rate value signal.

2. The system of claim 1 in which said second interval is about two seconds.

3. The system of claim 1 in which said first interval is about one half of a second.

4. The system of claim 1 in which said processing circuit is responsive to said second target count signal and a third interval to derive said third count rate value signal, and for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said third count rate value signal.

5. The system of claim 4 in which said third interval is about six seconds.

6. The system of claim 1 in which:

said control assembly display is responsive to a background count rate signal to provide a visually perceptible background count rate output corresponding with said background radiation, said assembly supporting a background count switch actuable to derive a background signal; and

said processing circuit is responsive to said count signal in response to said background signal to derive said background count rate signal.

7. The system of claim 6 in which:

said processing circuit is responsive to said first count rate value signal and to said background count rate signal to derive a said graph signal sequentially energizing said segments from said first segment in correspondence with the difference between the count rate value of said first count rate signal and the count rate value of said background count rate signal.

8. The system of claim 6 in which:

said control assembly includes an audio network responsive to an audio input to provide an aurally perceptible output and including a mute switch actuable to derive a mute signal; and

said processing circuit is responsive to said first count rate value signal and to said background count rate signal to generate said audio input when the count rate value represented by said first count rate value signal exceeds the count rate value represented by said background rate signal by a statistically significant amount, and is responsive to said mute signal to block said generation of said audio input.

9. A system for detecting and locating sources of radiation associated with a locator exhibiting a predetermined energy level and located at a region of interest, comprising:

a probe moveable within said region of interest, having a detector operable under an applied predetermined voltage bias to provide a pulsed output corresponding with radiation from said source;

a control assembly including;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof with respect to said predetermined energy level to derive a count signal, a bias voltage circuit connected in bias voltage conveying relationship with said probe and detector and responsive to a bias selection input signal to derive said predetermined voltage bias,

a radionuclide selector switch actuable to derive a selector switch output representing said locator predetermined energy level;

a readout assembly responsive to a count rate value signal to provide a perceptible output corresponding therewith; and

a processing circuit responsive to said count signal for deriving said count rate value signal, and responsive to said selector switch output for deriving said bias selection input signal.

10. A system for detecting and locating sources of radiation associated with a locator at a region of interest evidencing background radiation, comprising:

a probe movable within said region of interest and having a pulsed output corresponding with radiation impinging thereon;

a control assembly having a perceptible output including a display assembly, a target count switch actuable to provide a target count signal, and a background count switch actuable to provide a background signal, said display assembly being responsive to a target count rate value signal to display a visually perceptible target count rate value, responsive to a background count rate signal to display a visually perceptible background count rate value, and responsive to a ratio signal to display a ratio value, a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal for a background interval in response to said background signal to derive said background count rate signal at the termination of said background interval, responsive to said count signal for a target count interval in the presence of said target count signal to derive said target count rate value signal at the termination of said target count interval, and responsive to derive said ratio signal at the termination of said target count interval in correspondence with the numerical value represented by said target count rate value signal divided by the numerical value represented by said background count rate signal.

11. The system of claim 10 in which said processing circuit provides said target rate value signal for a predetermined interval.

12. The system of claim 11 in which said processing circuit provides said ratio signal for a predetermined finite interval.

13. A system for detecting and locating a radionuclide derived source of radiation exhibiting a predetermined energy level within a region of interest, comprising:

a probe moveable within said region of interest and having a pulsed output with an amplitude value corresponding with said predetermined energy level;

a control assembly including;

a signal treatment circuit responsive to said probe pulsed output, having an energy window network including an upper limit comparator responsive to a select upper limit reference signal and to said pulsed output to provide an upper limit signal when said amplitude value exceeds the value of said selected upper limit reference signal, and further including a lower threshold comparator responsive to a select threshold reference signal and to said pulse output to provide a lower threshold signal when said amplitude value exceeds the value of said select threshold reference signal,

a discriminator circuit responsive to derive a count signal in response to said lower threshold signal occurring in the absence of said upper limit signal;

a radionuclide selector switch actuable to derive a selector switch output representing said radionuclide predetermined energy level;

a readout assembly responsive to a count rate value signal to provide a perceptible output corresponding therewith; and

a processing circuit responsive to said count signal for deriving said count rate value signal, and responsive to said selector switch output for deriving said select upper limit reference signal and said select threshold reference signal.

14. The system of claim 13 in which:

said readout assembly includes a display assembly responsive to a radionuclide selection signal to provide a visibly perceptible display representing said radionuclide; and

said processing circuit is responsive to said selector switch output for deriving said radionuclide selection signal.

15. A system for detecting and locating a source of radiation exhibiting a predetermined energy level within a region of interest comprising:

a probe movable within said region and having a pulse output with an amplitude value corresponding with said predetermined energy level and a given pulse width;

a control assembly including;

a signal treatment circuit responsive to said probe pulse output, having an energy window network including an upper limit network having an upper limit signal when said amplitude value exceeds an upper reference value, and a lower threshold network having a lower threshold signal when said amplitude value exceeds a lower threshold reference value, said lower threshold signal having a signal attribute corresponding with said given pulse width, and

a discriminator circuit responsive to derive a candidate count signal in response to said lower threshold occurring in the absence of said upper limit signal and responsive to provide said candidate count signal as a validated count signal when said lower threshold signal attributes corresponding with said given pulse width represent a pulse width below a comparative pulse width value representing noise;

a readout assembly responsive to a count value signal to provide a perceptible output corresponding therewith; and

a processing circuit responsive to said validated count signal to derive said count value signal.

16. The system of claim 15 in which said comparative pulse width corresponds with a pulse duration of about 12 microseconds.

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

a probe moveable within said region of interest and having a pulsed output corresponding with radiation from said source;

a control assembly having a perceptible output including a display responsive to a first count rate value signal to provide a first perceptible count rate output, responsive to a second count rate value signal to provide a second perceptible count rate output, responsive to a third count rate value signal to provide a third perceptible count rate output, responsive to a graph signal to provide a perceptible bar graph output with segments energizable from first to last, said display including a target icon assembly energizable in response to a target icon signal to provide a visually perceptible target icon display, and said control assembly supporting a target count switch actuable to derive first and second target count signals;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal and a first predetermined interval to derive said first count rate value signal, responsive to said first target count signal and a second interval to derive said second count rate value signal, for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said second count rate value signal, and said processing circuit being responsive to said first target count signal to intermittently derive said target icon signal in response to said second count rate value signal.

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

a probe moveable within said region of interest and having a pulsed output corresponding with radiation from said source;

a control assembly having a perceptible output including a display responsive to a first count rate value signal to provide a first perceptible count rate output, responsive to a second count rate value signal to provide a second perceptible count rate output, responsive to a third count rate value signal to provide a third perceptible count rate output, responsive to a graph signal to provide a perceptible bar graph output with segments energizable from first to last, said control assembly supporting a target count switch actuable to derive first and second target count signals, and including a target icon assembly energizable in response to a target icon signal to provide a visually perceptible target icon display;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal and a first predetermined interval to derive said first count rate value signal, responsive to said first target count signal and a second interval to derive said second count rate value signal, for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said second count rate value signal,

said processing circuit being responsive to said second target count signal and a third interval to derive said third count rate value signal, and for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said third count rate value signal; and

said processing circuit being responsive to said second target count signal to intermittently derive said target icon signal in response to said third count rate value signal.

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

a probe moveable within said region of interest and having a pulsed output corresponding with radiation from said source;

a control assembly having a perceptible output including a display responsive to a first count rate value signal to provide a first perceptible count rate output, responsive to a second count rate value signal to provide a second perceptible count rate output, responsive to a third count rate value signal to provide a third perceptible count rate output, responsive to a graph signal to provide a perceptible bar graph output with segments energizable from first to last, said control assembly supporting a target count switch actuable to derive first and second target count signals,

said control assembly display being responsive to a background count rate signal to provide a visually perceptible background count rate output corresponding with said background radiation, said assembly supporting a background count switch actuable to derive a background signal, and

said control assembly including a background count icon assembly energizable in response to a background icon signal to provide a visually perceptible background icon display;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal and a first predetermined interval to derive said first count rate value signal, responsive to said first target count signal and a second interval to derive said second count rate value signal, for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said second count rate value signal,

said processing circuit being responsive to said count signal in response to said background signal to derive said background count rate signal, and

said processing circuit being responsive to intermittently derive said background icon signal in response to said background signal.

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

a probe moveable within said region of interest and having a pulsed output corresponding with radiation from said source;

a control assembly having a perceptible output including a display responsive to a first count rate value signal to provide a first perceptible count rate output, responsive to a second count rate value signal to provide a second perceptible count rate output, responsive to a third count rate value signal to provide a third perceptible count rate output, responsive to a graph signal to provide a perceptible bar graph output with segments energizable from first to last, said control assembly supporting a target count switch actuable to derive first and second target count signals,

said control assembly display being responsive to a background count rate signal to provide a visually perceptible background count rate output corresponding with said background radiation, said assembly supporting a background count switch actuable to derive a background signal, and

said control assembly including an audio network responsive to an audio input to provide an aurally perceptible output and including a mute switch actuable to derive a mute signal;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal and a first predetermined interval to derive said first count rate value signal, responsive to said first target count signal and a second interval to derive said second count rate value signal, and for deriving said graph signal sequentially energizing said segments from first to last in correspondence with said derivation of said second count rate value signal,

said processing circuit being responsive to said count signal in response to said background signal to derive said background count rate signal, said processing circuit being responsive to said first count rate value signal and to said background count rate signal to generate said audio input when the count rate value represented by said first count rate value signal exceeds the count rate value represented by said background rate signal by a statistically significant amount, and is responsive to said mute signal to block said generation of said audio input.

21. A system for detecting and locating sources of radiation associated with a locator at a region of interest evidencing background radiation, comprising:

a probe movable within said region of interest and having a pulsed output corresponding with radiation impinging thereon;

a control assembly having a perceptible output including a display assembly, a target count switch actuable to provide a target count signal, and a background count switch actuable to provide a background signal, said display assembly being responsive to a target count rate value signal to display a visually perceptible target count rate value, responsive to a background count rate signal to display a visually perceptible background count rate value, responsive to a ratio signal to display a ratio value,

said control assembly including a target icon assembly energizable in response to a target icon signal to provide a visually perceptible target icon display;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal for a background interval in response to said background signal to derive said background count rate signal at the termination of said background interval, responsive to said count signal for a target count interval in the presence of said target count signal to derive said target count rate value signal at the termination of said target count interval, responsive to derive said ratio signal at the termination of said target count interval in correspondence with the numerical value represented by said target count rate value signal divided by the numerical value represented by said background count rate signal, and

said processing circuit being responsive to said target count signal to derive said target icon signal intermittently during said target count interval.

22. A system for detecting and locating sources of radiation associated with a locator at a region of interest evidencing background radiation, comprising:

a probe movable within said region of interest and having a pulsed output corresponding with radiation impinging thereon;

a control assembly having a perceptible output including a display assembly, a target count switch actuable to provide a target count signal, and a background count switch actuable to provide a background signal, said display assembly being responsive to a target count rate value signal to display a visually perceptible target count rate value, responsive to a background count rate signal to display a visually perceptible background count rate value, responsive to a ratio signal to display a ratio value,

said control assembly including a background count icon assembly energizable in response to a background icon signal to provide a visually perceptible background icon display;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal for a background interval in response to said background signal to derive said background count rate signal at the termination of said background interval, responsive to said count signal for a target count interval in the presence of said target count signal to derive said target count rate value signal at the termination of said target count interval, responsive to derive said ratio signal at the termination of said target count interval in correspondence with the numerical value represented by said target count rate value signal divided by the numerical value represented by said background count rate signal, and

said processing circuit being responsive to said background signal to derive said background icon signal intermittently during said background interval.

23. A system for detecting and locating sources of radiation associated with a locator at region of interest evidencing background radiation, comprising:

a probe movable within said region of interest and having a pulsed output corresponding with radiation impinging thereon;

a control assembly having a perceptible output including a display assembly, a target count switch actuable to provide a target count signal, and a background count switch actuable to provide a background signal, said display assembly being responsive to a target count rate value signal to display a visually perceptible target count rate value, responsive to a background count rate signal to display a visually perceptible background count rate value, and responsive to a ratio signal to display a ratio value,

said control assembly includes a ration icon assembly energizable in response to a ration icon signal to provide a visually perceptible ratio icon display;

a signal treatment circuit responsive to said probe pulsed output to carry out a validation thereof and derive a count signal; and

a processing circuit responsive to said count signal for a background interval in response to said background signal to derive said background count rate signal at the termination of said background interval, responsive to said count signal for a target count interval in the presence of said target count signal to derive said target count rate value signal at the termination of said target count interval, and responsive to derive said ratio signal at the termination of said target count interval in correspondence with the numerical value represented by said target count rate value signal divided by the numerical value represented by said background count rate signal, and

said processing circuit is responsive to derive said ratio icon signal at the said termination of said target count interval.

24. A system for detecting and locating a source of radiation exhibiting a predetermined energy level within a region of interest comprising:

a probe movable within said region and having a pulse output with an amplitude value corresponding with said predetermined energy level and a given pulse width;

a control assembly including;

a signal treatment circuit responsive to said probe pulse output, having an energy window network including an upper limit network having an upper limit signal when said amplitude value exceeds an upper reference value, and a lower threshold network having a lower threshold signal when said amplitude value exceeds a lower threshold reference value, said lower threshold signal having a signal attribute corresponding with said given pulse width,

said signal treatment circuit including a coupling capacitor responsive to said pulse output to provide a coupled pulse output at its output, and a baseline restoration circuit responsive to said coupled pulse output to clamp said capacitor output to a reference voltage level in the absence of said coupled pulse output,

said energy window network is responsive to said coupled pulse output to derive said upper limit signal and said lower threshold signal, and

a discriminator circuit responsive to derive a candidate count signal in response to said lower threshold occurring in the absence of said upper limit signal and responsive to provide said candidate count signal as a validated count signal when said lower threshold signal attributes corresponding with said given pulse width represent a pulse width below a comparative pulse width value representing noise;

a readout assembly responsive to a count value signal to provide a perceptible output corresponding therewith; and

a processing circuit responsive to said validated count signal to derive said count value signal.

25. The system of claim 24 in which said reference voltage level is electrical ground.