GB2191585A - Sensor indicating and controlling substance concentration - Google Patents
Sensor indicating and controlling substance concentration Download PDFInfo
- Publication number
- GB2191585A GB2191585A GB08701248A GB8701248A GB2191585A GB 2191585 A GB2191585 A GB 2191585A GB 08701248 A GB08701248 A GB 08701248A GB 8701248 A GB8701248 A GB 8701248A GB 2191585 A GB2191585 A GB 2191585A
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- concentrate
- temperature
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- chamber
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
- G01N27/16—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by burning or catalytic oxidation of surrounding material to be tested, e.g. of gas
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Apparatus For Disinfection Or Sterilisation (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
A sensor 10 for producing a signal representative of the instantaneous amount of a substance in an environment e.g. hydrogen peroxide in a sterilization chamber, comprises a first element 18 for producing a first signal representative of the temperature T1 of the environment. The first element is isolated from the substance. A second element 12 includes a material which is capable of interacting with the substance to modify the temperature T2 sensed by the second element. The second element produces a second signal representative of the modified temperature such that the first and second signals are representative of the instantaneous amount of the concentrate in the environment. The sensor 10 may be used in a system for indicating the instantaneous amount of a substance in an environment or in a system for controlling the instantaneous amount of a substance in a chamber. <IMAGE>
Description
SPECIFICATION
Sensor, indicating system and control system
The present invention is related generally to sensors, and more particularly to sensors for providing an instantaneous indication ofthe amount of a substance (hereinafter referred to as a concentrate) in an environment. The invention also relates to a system for indicating the amount of concentrate in an environment and to a system of controlling the amount of a concentration in an environment.
In many applications, it is necessary to monitor continuallytheamountofasubstancewithinan environment. For example, in sterilization chambers using vapour phase hydrogen peroxide for sterilization, it is important to monitor the concentration of the hydrogen peroxide within the chamberforthe purposes of controlling the amount of hydrogen peroxide used and for verifying the sterilization atmosphere. Cu rrently, there is no practical method of measuring directythe instantaneous amount or concentration of vapour phase hydrogen peroxide during a sterilization cycle although various methods currently existfor indirectly measuring the concentration of vapour phase hydrogen peroxide.
An example of indirect measurementtechniques includes using the rise in pressure as an indication of the concentration ofvapour phase hydrogen peroxide. However, the pressure reading may not be accurate due to the presence of watervapourwhich has similar properties. Biological testing which involves placing organisms in the sterilizer provides information thatthe concentration was high enough to kill the organisms, but not what the concentration was. Additionally, because of long incubation times and the associated load quarantine period, biological testing does not provide instantaneous readings.
Direct concentration measurement techniques, such as placing responsive or sensitive paper in the sterilizer, do not provide continuous measurements because the quantity of concentrate in the paper is cumulative. Methods relying on absorption ofthe sterilant into a carrier during all or part of the cycle followed by subsequent spectrometric analysis of the carrier cannot be used for control and are only marginally beneficial for verification. Directly taking samples of gas can lead to contamination problems which may cause the hydrogen peroxide to decompose into its constituent elements.
Additionally, because the sterilizer is typically working art a deep vacuum, an even deepervacuum is required to draw out a sample. Thus,there is a practical need for instantaneously measuring the amount of a sterilant in an environment for both controlling the amount of sterilant used as well as for verifying the proper sterilizing atmosphere.
The present invention in its broadest aspects is directed to a sensorfor producing a signal representative of the instantaneous amount of a concentrate in an environment comprising first means for producing a first signal representative of the temperature ofthe environment;
shield means for isolating said first means from the concentrate; and
second means including a material capable of interacting with the concentrate to modify the temperature sensed by said second means, said second means serving for producing a second signal representative of said modified temperature such that said first and second signals are representative ofthe instantaneous amount ofthe concentrate in the environment.
The second means of the sensor may include a platinum resistance temperature detector capable of interacting with a hydrogen peroxide concentrate.
The sensor ofthe present invention may form the basis of a system for indicating the instantaneous amount of a concentrate in an environment. Such a system comprises a first resistive element isolated from the concentrate for producing a first signal representative of the temperature of the environment; second resistive element exposed to the concentrate and constructed of a material capable of interacting with the concentrate to modify the temperature sensed by the second resistive element, said second resistive element serving for producing a second signal representative ofthe modified temperature; means responsive to thefirst and second signals for producing an output signal representative of the instantaneous amount of concentrate in the environment; and an output device responsive to the output signal.
The system ofthe present invention for indicating the instantaneous amount of a concentrate may be used for controlling the instantaneous amount of a concentrate in a chamber. Such a control system comprises a first resistive element positioned in the chamber and isolated from the concentrate for producing a first signal representative of the temperature in the chamber; a second resistive element exposed to the concentrate and constructed of a material capable of interacting with the concentrate to modifythe temperature sensed by the second resistive element, the second resistive element serving for producing a second signal representative of the modified temperature, said first and second signals being representative ofthe instantaneous amount of concentrate in the chamber; meansforincreasingtheamountof concentrate in the chamber; means for decreasing the amount of concentrate in the chamber; and a control circuit responsive to the first and second signalsforproducingoutputsignalsforcontrolling the means for increasing the amount of concentrate in the chamber and the means for decreasing the amount of concentrate inthechambersuchthatthe instantaneous amount of concentrate in the chamber is controlled.
The sensor and systems of the present invention enablethe instantaneous amount of a concentrate to be precisely and continuously determined. Because ofthis, processes, such as sterilization cycles, may be monitored precisely for controlling the amount of sterilant used and to ensure sufficiently high sterilant concentrations over sufficiently long periods to ensure proper sterilization.
The present invention is further described, byway of example, with reference to the accompanying drawings, wherein:
Figure 1 illustrates a sensor constructed according to the present invention;
Figure2 illustrates a system for controlling the instantaneous amount of a concentrate in a chamber using the sensor of the present invention; Figure3 isa graph illustrating a typical known hydrogen peroxide sterilization cycleforwrapped microsurgical instruments; and Figure4is a block diagram illustrating the components ofthe control circuit illustrated in
Figure 2.
As shown in Figure 1, a sensor 10 constructed according to the present invention comprises a first resistive element 18 wound about a core 20. The first element 18 has a pair of leads 22 and 23 extending therefrom. A second resistive element 12 is wound in a spiral about a core 14. The second element 12 has a pair of leads 15 and 16 extending therefrom.
Thefirstelement18 isenclosed in athin, heat-transmissive, inert plastics or glass sleeve 25.
The first element 18 and the second element 12 are held proximate to one another by a substrate 27. In an environment of airorwatervapour, both elements 12and 18will measurethesame temperature because of their proximity to one another. Some minimum time lag will be experienced by the first resistive element 18 due to the sleeve 25. However, thattime lag is kept to a
minimum by making the sleeve 25 verythin and of a
material having good heat-transmissive properties.
The sensor 10works on the principle that the
resistive element 12 will interact with the concentrate being sensed. For example, if the
second element 12 and the first element 18 are
constructed of platinum, a concentrate, such as
hydrogen peroxide vapour, will catalyze in the presence ofthe platinum of the exposed second
element 12 and breakdown into its component parts,
namely oxygen and water, while giving off heat
according to well-known chemical equations. The first element 18 will measurethevapourtemperature T1 only while the exposed second element 12 will measure a proportionally elevated temperature T2.
The difference in the temperatures measured by the first element 18 and second element 12 is
representative of the hydrogen peroxide vapour
concentration.
The amount of platinum in element 12 should be
kept small such that the amount of hydrogen
peroxide vapour catalyzed will be small and will not
sufficiently affect the overall hydrogen peroxide
concentration in the chamber. The breakdown of the
hydrogen peroxide vapour is an ongoing process
and heat will continually be generated. The
temperature ofthe second element 12 will rise
slightly above ambient and give off heat to the
surrounding area. By maintaining the overall
amount of platinum in element 12 small, the heat
given offto the surrounding area will not affect the
temperature sensed bythe first element 18.The
temperature sensed by the second element 12 will eventually reach an equilibrium ata higherthan ambienttemperature which is proportional to the hydrogen peroxidevapourconcentration.
Additionally, the vapour concentration ofthe environment should be kept at or below saturation such thatthe water vapour by-product ofthe cataiyzation process will remainvapourized and not foul the second element 12.
The foregoing principle is equally applicableto other types of concentrates providing that the second element 12 is constructed of a material capable of interacting with the concentrate to modify the temperature sensed by the second element 12. In addition, it is recognized that chemical reactions may result between certain sensors 12 and concentrates which may be reversible thereby enabling the sensors 1 2to be rejuvenated or which may be irreversible thereby leading to consumption of the sensors 12.
As described above, the first element 18 measures the tem peratu re T1 of the environment. The exposed second element 12 measures a highertemperature
T2 as a result of the catalytic decomposition ofthe vapour phase hydrogen peroxide. This second temperatureT2 is a function of the environmental temperature as well as the concentration of the vapour phase hydrogen peroxide as indicated by equation (1).
T2--fl(T1,C)...eq(1) The sterilant concentration can be determined by rearranging equation (1 ) as follows: C = 2 (T1, T2) ... eq (2) Equation (2) assumes a relatively constant operating pressure P. Otherwise, equation (2) can be generalized: C = F3 (T1, T2, P) ... eq (3) In a practical application, the temperature of a sterilization chamber is controlled at 55"C and evacuated to 1 OmmHg absolute pressure (1.33 kPa, absolute), for example. Under these circumstances, T1 and P from equation (3) are constant and can thus
be ignored.Equation (3) can then besimplified: C=f4(T2-T1)... eq (4) The simplified equation (4) applies only if
operation is over a narrow range of temperatures
and pressures. Otherwise, the more general equation (3) should be used.
A look-up or empirical table approximating the functions f3 and f4can be generated. This is
accomplished according to known procedures by
exposing the sensor 10 to various known
concentrations of vapour phase hydrogen peroxide.
By holding the tem peratu re T1 and pressure P
constant, the f4 data is determined as a function of the difference ofthetwo temperature readings. By varying thetemperature T1 and pressure P1,thef3 data is determined as a function of the two
temperatures and the pressure. Thus, appropriate
look-up tables can be generated.
Figure 2 illustrates a control system using the sensor 10 of the present invention for controlling the amount of hydrogen peroxide in a sterilization chamber 30. The sterilization chamber 30 is connected to a hydrogen peroxide tank 32 through a line 34. The flow of hydrogen peroxide from the tank 32 to the sterilization chamber 30 throughh the line 34 is controlled by a valve 36.
The flow of material from the sterilization chamber 30 is controlled bya vacuum pump 38 connected to the sterilization chamber 30 through a line 40. The flow of material through the line 40 is controlled by a valve 42. The sterilization chamber 30 may also be vented through a vent line 44. The vent line 44 has a valve 46 for controlling the flow of material through the vent line 44.
The temperature signals T1 and T2 produced by the sensor 10 are input to a control circuit 48 through an input line 50. A pressure sensor 52 produces a signal representative ofthe pressure Pwhich is input to the control circuit 48 through an input line 54. In response to this raw data, the control circuit 48 produces output signals as described further hereinbelow which are output on lines 56, 58, 60, 62 and 64 for controlling the operation ofvalve 36, a heater 59, the valve 42, the valve 46, and the vacuum pump 38, respectively.The control circuit may also producean outputsignal outputon line 66 to an indicator 68 for indicating the instantaneous value of the hydrogen peroxide concentration in the sterilization chamber 30.
The sterilization chamber 30 illustrated in Figure 2 may be operated according to any of various wel l-known sterilization cycles. Atypical known hydrogen peroxide sterilization cycle used for wrapped microsurgical instruments is illustrated in Figure 3. Thegraph illustrated in Figure3showsthat the variables during a sterilization cycle include the depth ofthevacuumwhich isdrawn in the sterilization chamber30, the amount of hydrogen peroxide injected into the chamber per pulse, the hold time of each pulse, the number of pulses, the temperature within the sterilization chamber 30, and the concentration of the hydrogen peroxide sterilant.
In Figure3,avacuum is drawn inthesterilization chamber 30 for approximately the first eight minutes ofthe sterilization cycle during which timethe sterilization chamber is heated. At approximately eight minutes into the cycle, hydrogen peroxide is injected into the sterilization chamber 30 which decreases the vacuum within the sterilization chamber 30. At approximately ten minutes into the sterilization cycle, the pressure within the sterilization chamber 30 stabilizes and is held for approximately three minutes. At thirteen minutes into the sterilization cycle, the vacuum pump 38 is operated to draw the vacuum in the sterilization chamber 30 back down to its original value. When the vacuum is returned to its original value, another pulse of hydrogen peroxide is injected into the sterilization chamber.This procedure of drawing a vacuum and injecting hydrogen peroxide is repeated a number oftimes until sterilization is complete. At thattime, approximately forty minutes into the sterilization cycle, the sterilization chamber 30 is vented to atmosphere.
A block diagram illustrating the components ofthe control circuit 48 is illustrated in Figure 4. The control circuit 48 includes a first current source 70 for providing current to the first resistive element 18 and a second current source 72 for providing currentto the second resistive element 12. The provision of current sources 70 and 72 for resistancetemperature detectors 12 and 18 is well-known in the art. The signals produced bythefirstand second current sources70 and 72 respectively, are input to a time multiplexor 74. These signals, which are representative of the temperatures T1 and T2, are alternately input to a sample and hold circuit 76.The outputofthe sample and hold circuit76 is amplified by an amplifier 78. The amplified signal is converted to digital form by an analog to digital converter80.
The digital signals representative of the temperaturesT1 and T2 are inputto a microprocessor 82 through an input/output port 84.
The microprocessor 82, operating according to instructions stored in a memory 86, controls the operation of the multiplexor74, sample and hold circuit76,and A/D converter80through the input/output port 84 in a known manner.
In operation, the microprocessor 82 enables the multiplexor74such that one ofthetemperature signals T1 and T2 is presented to the sample and hold circuit 76. The sample and hold circuit 76 holds that analog value for a sufficient period oftime such that the analog to digital converter 80 converts the analog value into a digital value. That digital value is read into the microprocessor 82 which then repeats the process to input a value representative of the othertemperature measurement.
In an embodiment wherein the pressure remains constant during the time period of interdst the pressure reading P on line 54 is used for purposes of performing a sterilization cycle such as the one illustrated in Figure 3 and is not needed for determining the concentration ofthe hydrogen peroxide vapour. As seen from equation (4) above, after the microprocessor 82 has read in values co rrespon d ing to the tem peratu res T1 and T2, the two temperatures are subtracted from one another to produce a temperature differential. The temperature differential is compared to an empirical data consisting oftemperature differentials and corresponding hydrogen peroxide concentrations stored in memory 86. When a match is located,the hydrogen peroxide concentration corresponding to thattemperature differential is selected by the microprocessor 82. Atthis-point, the microprocessor 82 may display the selected hydrogen peroxide concentration by outputting a signal on line 66 to the indicator 68.
The selected value of the hydrogen peroxide concentration may also be compared by the microprocessor 82 to a set-point value to determine if the instantaneous concentration is either above or below the set-pointvalue. If below, the microprocessor 82 may output a signal on line 56to open valve 36 thereby enabling additional hydrogen peroxide to flowfrom the tank 32 to the sterilization chamber 30. If the instantaneous value ofthe hydrogen peroxide is above the set-point value, then a signal may be output bythe microprocessor 82 on line 60 to open valve 42 and a signal may be output on line 64to begin operation ofthe vacuum pump 38 to remove hydrogen peroxide from the sterilization chamber 30.Alternatively, a signal may be output on line 62 to open valve 46 to enable hydrogen peroxide to flow out of the sterilization chamber30through vent line 44. In this manner, the microprocessor82, using the raw data produced bythe sensor 10, controls the concentration of the hydrogen peroxide in the sterilization chamber 30.
In the eventthatthe pressure within the sterilization chamber 30 is not maintained constant during the time period of interest, then empirical data correspondingtothe information required by equation (3) may be stored in the memory 86. The microprocessor 82 will take the raw temperature data representative of the temperature T1 and T2 together with the raw pressure data representative of the pressure P and compare those readings with the information stored in the memory 86. When there is a match between the measured temperatures T1 and
T2and measured pressure Pwith stored values for the temperatures T1 and T2 and the pressure P, the microprocessor82will selectthecorresponding hydrogen peroxide concentration.This selected concentration may be displayed by indicator 68 or compared with a set-point for controlling the system as described hereinabove. The hydrogen peroxide concentration may be determined as often as desired.
In addition to the functions just described, the microprocessor 82 causes the sterilization cycle shown in Figure3to be performed. Forexample,the microprocessor 82 periodically compares the temperatureT1 with a reference temperature. In the eventthetemperature T1 falls below the reference temperature, the microprocessor 82 may output a signal on line 58 to energise heater 59 to thereby control the temperature in the sterilization chamber 30 according to the desired sterilization cycle.
Additionally, the microprocessor 82 may use the signal representativeofthe pressure P in the sterilization chamber 30 to control the pressure. This can be accomplished by comparing the pressure signal P to various reference pressures foilowed by manipulation of the valves 36,46, or 42, together withthevacuum pump 38 in orderto control the pressure according to the desired sterilization cycle.
While the present invention has been described in connection with an exemplary embodiment thereof, many modifications and variations may be made.
For example, sensors comprised of elements constructed of materials otherthan platinum may be used in combination with the sensing of other sterilants. Also, there are numerous schemes for inputting raw data to a microprocessor otherthan that illustrated in Figure 4.
Claims (21)
1. A sensor for producing a signal representative of the instantaneous amount of a concentrate in an environment comprising first means for producing a first signal representative of the temperature of the environment;
shield means for isolating said first means from the concentrate; and
second means including a material capable of interacting with the concentrate to modify the temperature sensed by said second means, said second means serving for producing a second signal representative of said modified temperature such that said first and second signals are representative ofthe instantaneous amount ofthe concentrate in the environment.
2. A sensor as claimed in claim 1, wherein said shield means includes a heattransmissive sealing means.
3. Asensorasclaimedinclaiml or2, additionally comprising a substrate for carrying said first and second means such that, in the absence of the concentrate, said first and second means sense substantially the same temperature.
4. A sensor as claimed in claim 1,2 or 3, wherein said first and second means include first and second resistive temperature detectors, respectively.
5. Asensoras claimed in any of claims 1 to4, wherein said second means includes a platinum resistive element capable of interacting with a hydrogen peroxide concentrate.
6. A sensor as claimed in claim 5, wherein the amount of platinum is small, such thattheambient temperature measured by said first means is unaffected by the interaction of said platinum with the hydrogen peroxide.
7. A system for indicating the instantaneous amount of a concentrate in an environment, comprising:
a first resistive element isolated from the concentrate for producing a first signal representative ofthe temperature ofthe environment;
a second resistive element exposed to the concentrate and constructed of a material capable of interacting with the concentrate to modify the temperature sensed by said second resistive element, said second resistive element serving for producing a second signal representative of said modified temperature;
means responsive to said first and second signals for producing an output signal representative ofthe instantaneous amount of concentrate in the environment; and
output means responsive to said output signal.
8. A system as claimed in claim 7, additionally comprising first and second current sources for providing power for said first and second resistive elements, respectively.
9. Asystem as claimed in claim 7 or8,wherein said meansfor producing an output signal includes a control circuit, and said system additionally comprises means for inputting said first and second signals to said control circuit.
10. A system as claimed in claim 9, wherein said meansforinputting includes a time multiplexor, a sample and hold circuit, and an analog to digital converter, all serially connected and controlled by said control circuit.
11. Asystem as claimed in claim 9 or 10, wherein said control circuit includes means for subtracting said first and second signals from one anotherto
produce differential temperature signals, memory
means for storing empirical data containing differential temperature values together with corresponding values representative of amounts of the concentrate, and means for comparing said differential temperature signals to said stored differential temperature values.
12. A system as claimed in claim 9 or 10, additionally comprising a sensor for producing a
pressure signal representative of the environmental
pressure, and wherein said control circuit produces said output signal in response to said first and second signals and said pressure signal.
13. A system as claimed in claim 12, wherein said control circuit includes memory means for storing empirical data containing valuesforsaidfirstand second signals and said pressure signals together with corresponding values representative of amounts of the concentrate, and means for comparing said first and second signals and said pressure signal with said stored values.
14. A system for controlling the instantaneous amount of a concentrate in a chamber, comprising:
a first resistive element positioned in the chamber and isolated from the concentrate for producing a first signal representative of the temperature in the chamber;
a second resistive element exposed to the concentrate and constructed of a material capable of interacting with the concentrate to modify the temperature sensed by said second resistive element, said second resistive element serving for producing a second signal representative of said modified temperature, said first and second signals being representative ofthe instantaneous amount of concentrate in the chamber;
means for increasing the amount of concentrate in the chamber;
means for decreasing the amount of concentrate in the chamber; and
control means responsive to said first and second signals for producing output signals for controlling said means for increasing and said means for decreasing such that the instantaneous amount of the concentrate in the chamber is controlled.
15. A system as claimed in claim 14, wherein the chamber includes a sterilization chamber and wherein the concentrate includes hydrogen peroxide vapour.
16. A system as claimed in claim 15, wherein said meansforincreasingincludesasourceofhydrogen peroxide vapour connected to the chamberthrough a valve controlled by said control means.
17. Asystem as claimed in claim 14, 15or16, wherein said means for decreasing includes a vacuum pump connected to the chamberthrough a valve, said valve and said vacuum pump being controlled by said control means.
18. A system as claimed in claim 17, wherein said means for decreasing includes a vent pipe connected tothechamberthrough a valve controlled by said control means.
19. Asensorconstructed and adapted to operate substantially as herein described with reference to and as illustrated in Figure 1 of the accompanying drawings.
20. Aconcentration indicating system constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.
21. A quantity controlling system constructed, arranged and adaptedto operate substantially as herein described with reference to and as illustrated in the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US87203986A | 1986-06-09 | 1986-06-09 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8701248D0 GB8701248D0 (en) | 1987-02-25 |
| GB2191585A true GB2191585A (en) | 1987-12-16 |
Family
ID=25358700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08701248A Withdrawn GB2191585A (en) | 1986-06-09 | 1987-01-21 | Sensor indicating and controlling substance concentration |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS62293147A (en) |
| DE (1) | DE3638789A1 (en) |
| GB (1) | GB2191585A (en) |
| SE (1) | SE8700064L (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5234124A (en) * | 1992-03-13 | 1993-08-10 | American Sterilizer Company | Cassette for sterilizing articles and latch therefor |
| US5317896A (en) * | 1992-03-13 | 1994-06-07 | American Sterilizer Company | Method of detecting liquid in a sterilization system |
| US5445792A (en) * | 1992-03-13 | 1995-08-29 | American Sterilizer Company | Optimum hydrogen peroxide vapor sterlization method |
| US5527507A (en) * | 1992-10-01 | 1996-06-18 | American Sterilizer Company | Accumulator based liquid metering system and method |
| US5534221A (en) * | 1992-03-13 | 1996-07-09 | American Sterilizer Company | Device and system for sterilizing objects |
| WO1998000176A1 (en) * | 1996-07-03 | 1998-01-08 | American Sterilizer Company | Monitoring and control of sterilization processes with semiconductor sensor modules |
| WO2001045754A1 (en) * | 1999-12-21 | 2001-06-28 | Ethicon, Inc. | Monitoring of sterilant apparatus and method for monitoring sterilant |
| EP1308718A2 (en) * | 2001-11-02 | 2003-05-07 | Ethicon, Inc. | Apparatus and method for monitoring of oxidative gas or vapor |
| EP1308174A1 (en) * | 2001-11-02 | 2003-05-07 | Ethicon | Method and apparatus for monitoring sterilant concentration in diffusion-restricted regions |
| US7025732B2 (en) | 2003-02-25 | 2006-04-11 | Ethicon Endo-Surgery, Inc. | Biopsy device with variable speed cutter advance |
| DE102005020459A1 (en) * | 2005-04-29 | 2006-11-09 | Sig Technology Ag | Method and device for the detection of substances in aqueous, gaseous media |
| US7252641B2 (en) | 2003-02-25 | 2007-08-07 | Ethicon Endo-Surgery, Inc. | Method of operating a biopsy device |
| WO2011070600A1 (en) * | 2009-12-10 | 2011-06-16 | Sidel S.P.A. Con Socio Unico | Sterilising and disinfection apparatus |
| US10595831B2 (en) | 2012-05-30 | 2020-03-24 | Devicor Medical Products, Inc. | Control for biopsy device |
| US11179141B2 (en) | 2006-12-13 | 2021-11-23 | Devicor Medical Products, Inc. | Biopsy system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU4748590A (en) * | 1988-12-12 | 1990-07-10 | Yale Materials Handling Corporation | Means and method for measuring inductance |
| US5876664A (en) * | 1996-06-14 | 1999-03-02 | American Sterilizer Company | Continuous-operation, closed loop decontamination system and method |
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- 1986-11-13 DE DE19863638789 patent/DE3638789A1/en not_active Withdrawn
- 1986-12-08 JP JP29226486A patent/JPS62293147A/en active Pending
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- 1987-01-21 GB GB08701248A patent/GB2191585A/en not_active Withdrawn
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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Also Published As
| Publication number | Publication date |
|---|---|
| SE8700064L (en) | 1987-12-10 |
| JPS62293147A (en) | 1987-12-19 |
| GB8701248D0 (en) | 1987-02-25 |
| SE8700064D0 (en) | 1987-01-09 |
| DE3638789A1 (en) | 1987-12-10 |
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| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |