Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
2000-10-30
2002-08-27
La, Anh N. (Department: 2632)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S632000, C073S023200
Reexamination Certificate
active
06441743
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a system and method for calculation of hazard levels of chemical/biological
uclear agents in an environment, and more particularly to a method developed to generate hazard level indication in detectors of chemical, biological, or nuclear agents.
More in particular, the present invention relates to a technique developed to indicate the accumulated dosage that is hazardous to humans or other living organisms which estimates hazard level values by applying an exponentially weighted moving integration to measure the concentrations of the chemical/biological
uclear agent in the environment. The system generates an indication of the level of hazard when the estimated hazard level values match or exceed empirically predetermined hazard dosage values for the agent in question.
BACKGROUND OF THE INVENTION
Medical problems experienced by Armed Forces personnel has created a need to understand and provide warning when the level of accumulated dosage of a chemical, biological or nuclear agent reaches or exceeds the dosage level which would be harmful to the personnel exposed to the agent in question for a certain periods of time. Knowing the level of hazards for chemical/biological
uclear agents would allow military commanders to change or adjust their operating procedures in order to prevent the personnel from exposure to harmful dosages of dangerous agents. There are no known algorithms that address the question of how to indicate the accumulated dosage of a chemical/biological
uclear agent that may be hazardous to humans or other living organisms.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a technique of determining hazard levels of chemical/biological
uclear agents in an environment and which warns a user when the accumulated dosage reaches or exceeds a hazard level.
It is another object of the present invention to provide an algorithm applicable to chemical, biological and nuclear detectors which would calculate accumulated dosage of an agent accumulated over a period of time, estimate hazard level values by applying an exponentially weighted moving integration to the measured concentrations of the detected chemical/biological
uclear agent, and generate an indication of level of hazard when the estimated hazard level values match or exceed certain predetermined hazard dosage values determined empirically as harmful for the health of living organisms exposed to the agent in question.
The technique as herein described is directed to determining hazard levels and warning the users when the accumulated dosage of the chemical, biological or nuclear agent reaches the hazard levels and is envisioned to be applicable to any type of chemical, biological, or nuclear agent. According to the teaching of the present invention, a method of determining hazard levels of a vapor (chemical, nuclear, or biological agent) in an environment includes the steps of:
measuring concentrations of the agent in the environment;
estimating hazard level values of the agent by applying an exponentially weighted moving integration to the measured concentrations;
predetermining hazard dosage values defined empirically as harmful for living organisms;
comparing the estimated hazard level values to the predetermined hazard dosage values; and
generating an indication of the level of hazard when the estimated hazard level values match or exceed the empirically predefined hazard dosage values of the agent.
Preferably, the hazard dosage values are predetermined as falling in three dosage ranges, i.e., a low hazard dosage value, a medium hazard dosage value, and a high hazard dosage value, which for each chemical, biological or nuclear agent are represented by a corresponding value.
Essentially, an algorithm developed as a core of the present invention processes chemical vapor concentration measurements and generates chemical vapor hazard levels. This algorithm provides an estimate of hazard level values by using an exponentially weighted moving integration (further referred to herein as EWMI) of chemical vapor concentrations.
EWMI has important advantages over a standard moving integration:
(A) EWMI reduces the storage required to keep a history of the chemical vapor concentrations to one value per chemical vapor type; and,
(B) EWMI permits the automatic adjustment of the integration period and the decay rate for the accumulation of concentration as a function of the concentration level of the agent vapors.
The algorithm of the present invention uses EWMI to generate estimated detected agent hazard level values. When the EWMI calculated values match or exceeds the empirically set hazard levels the algorithm generates an indication of the level of the hazard.
The algorithm calculates the cumulative dosage according to the following equation:
D
i
=D
i−1
+in
i
·IST+D
0
,
wherein
D
i
=the cumulative dosage at the i
th
sample,
D
i−1
=the dosage previous to the i
th
sample,
in
i
=the measured concentration at the i
th
sample,
IST=the independent sample time, and
D
0
=the initial value of the dosage.
The estimated hazard level values are calculated by the algorithm of the present invention according to:
DI
i
=DI
i−1
+in
i
·IST−TR
i
·−DI
i−1
·IST
wherein
DI
i
=the exponentially weighted moving integral at the i
th
sample,
DI
i−1
=the exponentially weighted moving integral previous to the i
th
sample,
in
i
=the measured concentration at the i
th
sample,
IST=the independent sample time, and
TR
i
=the i
th
decay rate.
The decay rate TR
i
is calculated by estimating the time period necessary for a measured concentration to reach a next higher predetermined hazard dosage value.
These and other novel features and advantages of this invention will be fully understood from the following detailed description of the accompanying Drawings.
REFERENCES:
patent: 4644331 (1987-02-01), Matsushita et al.
patent: 4796205 (1989-01-01), Ishii
patent: 5049861 (1991-09-01), Grace
patent: 5966079 (1999-10-01), Tanguay
patent: 5969623 (1999-10-01), Fleury et al.
La Anh N.
Rosenberg , Klein & Lee
The Mitre Corporation
LandOfFree
Method and apparatus for determining hazard levels of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for determining hazard levels of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for determining hazard levels of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2931653