JPH0624577B2 - Sterilization apparatus and method - Google Patents

Description

The present invention relates to a sterilization method for articles such as surgical instruments and dentist's instruments, and more particularly to a sterilization device and a sterilization method using fluorine carbide as a sterilization medium.

In the fields of health sciences and health services, it is a task to sterilize surgical instruments, dentists' instruments and the like in order to destroy a wide range of microorganisms. Various sterilization techniques have been employed including exposing the article to chemical vapors such as ethylene oxide or to X-rays, to wet heat, or to dry heat. The two most widely used techniques are the moist heat method using pressurized saturated steam in autoclaves and the like and the dry heat method in certain types of ovens.

Steam autoclave disinfectors are very bulky, expensive, and usually require the use of distilled water, which causes steam to corrode (unless preservatives are used) and also to create a dull edge. May be. High temperature oven sterilizers are very slow to reach the cost of sterilization and sterilize to remove any material that protects the underlying microbes or burns on the surface of the article. It is required that the articles to be cleaned be thoroughly washed and dried in advance. Also, if several items are to be sterilized at once, these items must be specially packaged or placed in an oven to uniformly sterilize all of these items.

A paper entitled "Rapid Heat Sterilization Using Fluorocarbon Vapor as a Heat Transfer Medium" by M. Klein and DG Millwood (21st International Conference in DF, Mexico, March 8-14, 1970) Reissued from the excerpt of the International Conference on Medicine, No. 222 OPHTHALMOLOGY), which discloses a method of sterilization using a fluorocarbon solution. Such liquids are substantially chemically and biologically inert, flame retardant, thermally stable and have a boiling point above the temperature required for sterilization. The liquid is heated to the boiling point so that the steam contacts and rapidly heats the article to be sterilized.

Until now, various sterilization devices using a hydrocarbon solution as a sterilization medium have been proposed. For example, US Pat.
No. 579,290 discloses a device in which a fluorocarbon liquid disposed in a lower portion of a chamber is heated to a boiling point so that surgical instruments and the like can be sterilized by being vaporized on the liquid. ing. U.S. Pat. No. 4,259,293 discloses the following configuration. That is, the chamber 10 is closed, the heater 13 is turned on to generate steam, and when the pressure sensor 16 detects a predetermined pressure, the valve 17 is opened to guide the steam to the reservoir 21 via the expansion valve 20 and the drying unit 19. When the temperature of the steam in the chamber rises, the temperature sensor 26 detects the temperature of the steam and closes the valve 17 in the open state, thereby filling the chamber with high temperature steam and performing sterilization work. To do. This work is the controller 2
7, the heater 13 is turned off, the valve 23 is opened and the fan 25 is operated, and the liquid in the reservoir 21 is returned to the chamber 10.

However, according to the above-mentioned conventional example, instead of the below-described ventilation passage means of the present invention, the electromagnetic valve 17 for circulating and recovering low-temperature steam, the expansion valve 20, the reservoir 21 separate from the chamber, and the electromagnetic valve 23. However, it requires various movable large parts such as the check valve 24, and has a drawback that the operation is extremely troublesome as well as the configuration. Moreover, the steam height level or the steam density is actually detected during the sterilization work. Since it does not have a feedback system, there is a drawback that the sterilization work is carried out as it is even when the steam leaks accidentally and the work reliability is insufficient.

An object of the present invention is to provide a sterilization device which has a simple structure and is easy to operate, which has a substantially inert, odorless and flame-retardant liquid such as a fluorocarbon liquid as a sterilization medium. To do.

Another object of the invention is to provide such a sterilization device that can be operated such that the loss of sterilization medium is minimized and that does not include a complicated vapor recovery system.

That is, the present invention is a sterilization apparatus having a housing (12) having an openable and accessible enclosure and defining an internal chamber (14) having an upper portion and a lower portion, and harmful to humans. A substantially non-toxic and substantially inert vaporizable germicidal solution having a boiling point high enough to kill microorganisms (22)
A reservoir means (20) arranged in the lower part of the chamber (14) for accommodating the sterilizing liquid, and the rising blanket for heating and vaporizing the sterilizing liquid and substantially saturated with the sterilizing liquid. Electric heating means (24) for supplying (39), and said reservoir means (2) for supporting the article (36) to be sterilized and for passing the ascending vapors in contact with said article (2).
0) a supporting means (38) arranged above the electrical energy source (28) and an electric control circuit means (30) connected to the heating means (24), said heating means (24). Electrical control circuit means (30) for controlling the operation of the chamber and thereby controlling the level of vapor in the chamber, the control circuit means (30) including the support means (38) and Articles supported on it (3
6), which is arranged above the detection means (46) for detecting the presence or absence of the blanket (39) having a relatively high vapor density, and the detection means (46) and the heating means (24) are electrically interconnected. Means (48), said detection means (4
6) enables the flow of electrical energy to the heating means (24) in response to detecting the absence of the steam blanket, and further the article when the detecting means detects the presence of the steam blanket. The interconnecting means (48) for stopping the flow of electrical energy to the heating means after a predetermined period of time sufficient to sterilize the device, and an opening to the atmosphere throughout the normal operation of the device. Venting means (60, 100) for providing and discharging the air displaced by the ascending vapor blanket from the chamber into the atmosphere, the inlet communicating with the chamber above the sensing means (46). (40, 104)
And the vent passage means (60, 100) having an outlet (66, 106) communicating with the atmosphere.

Therefore, the configuration of the above invention has the following effects.

Ventilation means (60, 100) is provided so that the chamber space is always in communication with the atmosphere, and only the air displaced by the steam blanket in the chamber during the sterilization process is appropriately discharged into the atmosphere to perform the sterilization process. In the case of the above-mentioned conventional example, in addition to the basic components such as the chamber 10, the pressure sensor 16 and the temperature sensor 26, the electromagnetic valve 1 is used to circulate and recover low-temperature steam.
7, expansion valve 20, reservoir 21 separate from chamber,
Compared with those requiring various movable large-sized parts such as the electromagnetic valve 23 and the check valve 24, it is only necessary to provide the air passage means having a simple structure, so that the whole structure and the work procedure can be greatly simplified. .

Further, as described in claims 2 to 4 of the present application, when the vapor recovery means is provided in the ventilation path means, the ventilation path means itself can recover the vapor of the sterilizing liquid, and thus a further structure is provided. Can be simplified.

By means of the interconnection means (48) between the sensing means (46) and the heating means (24) of the electrical control circuit (30),
In response to the detection of the presence or absence of the steam blanket by the detection means (46), the heating means is turned off after a predetermined time when there is steam, and the heating means is turned on when there is no steam, and the chamber is eventually turned on during the sterilization process. Since the steam blanket inside is controlled by feedback so that it is actually maintained at a constant height level, the reliability of the sterilization operation can be greatly improved.

On the other hand, according to the above-mentioned conventional example, after the temperature sensor 26 closes the valve 17 and starts the sterilization work, this work simply continues for the set time of the timer. There is no feedback system to actually detect the vapor density or vapor height level when the vapor leaks accidentally due to poor performance or a hole in the chamber. It may be continued as it is, and there is a risk that the sterilization work will be insufficient.

Another aspect of the present invention includes a cover (16), an upper portion, and a substantially non-toxic and substantially inert vaporizable germicidal liquid having a boiling point high enough to kill microorganisms harmful to the human body. Reserve to do (2
0), a vent passage means (6) having an inlet (40, 104) communicating with the upper portion of the chamber and an outlet (66, 106) communicating with the atmosphere throughout the sterilization period.
0, 100) in the chamber (14), placing the article (36) to be sterilized in the chamber (14) above the reservoir (20), and the sterilizing solution. (22) is heated to be vaporized, and a substantially blanketed steam (3) of the sterilizing solution is saturated.
9) supplying the steam blanket in contact with the article to be sterilized and displaced to replace the air in the chamber to expel the air to the atmosphere through the vent passage means. The step of supplying the steam blanket (39) and the relatively high density of the steam in the chamber (14) above the article (36) to be sterilized and below the inlet of the vent passage means. Blanket (39)
And (46) measuring the presence or absence of the presence of a steam blanket (39) at the location, and then measuring the presence of the steam blanket (39) at the location for a predetermined period of time sufficient exposure of the article to steam for sterilization. A method for sterilizing articles such as surgical instruments and dentistry instruments, which comprises a step of continuing heating and a step of stopping heating of the sterilizing solution after the predetermined period.

According to the configuration of the other invention, the same effect as that of the one invention is obtained.

Shown in the drawings is a sterilization device 10 for sterilizing surgical instruments, dental instruments and the like. The sterilization device 10 has a housing 12 defining an internal chamber 14 and a tamper or cover 16. This cover 1
6 is engaged with the peripheral gasket 18 when closed,
This forms a seal to hold the vapor inside the chamber 14. If necessary, the front opening can be used instead of the cover 16.

A reservoir 20 containing a vaporizable germicidal solution 22 is provided in the chamber 14
Is located at the bottom of the. The reservoir 20 is, in the particular embodiment illustrated, an integral part of the chamber 14, but could be a separate removable container.

This bactericidal solution 22 has a boiling point high enough to destroy microorganisms harmful to the human body, especially hard shell spore Bacillus stearothermophilus within a relatively short period of 0.5 to 30 seconds (ie, disturb protein properties). Is a substantially non-toxic, substantially inert, vaporizable liquid having. Although it does not have an absolute limit, this germicidal solution is generally at least about 10
It should have a boiling point of 0 ° C, preferably at least about 150 ° C.

A fluorocarbon liquid having a completely fluorinated structure, that is, a fluorocarbon liquid having no chlorine or hydrogen in the molecular structure is preferable. What is more, in addition to being less toxic and biologically and chemically inert, these fluorocarbon liquids are colorless, odorless, flame-retardant, thermostable, and non-polar. This is because it has the property of being substantially dielectric. Further, these liquids have high density, low density, low heat of vaporization, and low surface tension, and leave almost no residue.
A preferred commercially available fluorocarbon liquid is a "fluorinate" liquid commercially available from 3M, ie, boiling point 102 each.
FC-7 having C, 165 C, 174 C and 215 C
5, FC-40, FC-43 and FC-70.

The sterilizing liquid 22 is immersed in the sterilizing liquid 22 or heated until it boiled by a suitable heating means placed in thermal communication with the reservoir 20. For the particular structure shown,
This heating means is a heating element 26 (third part) which is immersed in the sterilizing solution 22 and is made of a thermistor material having a positive temperature coefficient (PTC).
Including an electric heater 24. Such heaters can be made from a variety of materials such as barium titanate, beryllium oxide, etc. and usually have a Curie point that allows them to be self-regulating without a thermostat. A preferred commercially available PTC-type heater is commercially available under the registered trademark of "Thermaster" from American Corporation TD and GTE Sylvania Corporation.

This heating element can have various geometrical structures, but in order to increase the area for rapidly bringing the sterilizing solution 22 to its boiling point or vaporization level, that is, the heating area, the honeycomb as shown in FIG. It is preferable to have a structure or a similar multifaceted structure. Since the fluorocarbon liquid typically has a low dielectric value, the electrical heating element 26 does not need to be insulated from the germicidal liquid 22 by an electrical nonconductor. On the contrary, it can be placed in direct contact with the sterilizing liquid 22, thereby maximizing the heat transfer efficiency and minimizing the time required to bring the sterilizing liquid 22 to its boiling point. You can The PTC thermistor type heater is
It is particularly preferable because they have a predetermined maximum temperature (Curie point), and even if the level of the sterilizing liquid 22 is accidentally lowered below the top surface of the heater 24, it does not overheat.

The heater 24 is connected to a source of electrical energy 28 through an electrical control circuit 30 that includes a starter switch 32 that can be switched between an off position and an on position to energize the heater 24. The control circuit 30 also includes a light emitting diode (LED) 34 or similar indicating means that emits light whenever the heater 24 is activated.

Items to be sterilized, such as dental instruments 36, are placed on perforated shelves and supported on reservoir 20 or in removable perforated tray 38 as shown. Steam 39 from the boiling germicidal liquid 22 passes while contacting the device 36 as it rises upwards toward the top of the chamber 14. Although only one tray 38 is shown, there are two or more levels of vertically arranged shelves or trays 38.
Can also be used.

The vapor 39 of the sterilizing liquid 22 has a higher density than air, and therefore hardly mixes with air. This results in the formation of a relatively dense blanket of substantially saturated vapor that displaces the air in chamber 14 to the top. The displacement air expelled through the ventilation passages 40 in the cover 16 is either recovered or released to the atmosphere as described in more detail below. When this dense vapor contacts the instrument 36, it condenses and due to the low surface tension of the germicidal liquid, this condensate is quickly expelled into the reservoir 20. This condensate is quickly replaced by hot steam, which can be replaced by the appliance 36.
Contact with. As a result, rapid heating is performed.

A detection means for detecting the presence or absence of a relatively dense blanket of the sterilizing liquid vapor 39 is provided on the uppermost tray 38 and the device 36 indicated on the tray. In the particular embodiment shown, the vapor sensing means includes a temperature sensor 46 and a conventional temperature controller 48. The temperature controller 48 is set to a predetermined temperature which corresponds approximately to the desired sterilization temperature. The temperature controller 48 is connected to the heater 24 through the control circuit 30 and is operable to generate an output signal when the gas temperature in the vicinity of the temperature detector 46 exceeds a predetermined level, that is, a set temperature. I'm running. Other means such as conventional optical sensors can also be used to detect the presence or absence of a relatively dense vapor blanket.

When the appliance 36 is completely wrapped in steam 39, the steam blanket rises above the tray 36 and contacts the temperature sensor 46. When the temperature of the steam 39 that contacts the temperature sensor 46 exceeds the set point of the temperature controller 48, the temperature controller produces an output signal that initiates a sterilization cycle.

The temperature controller 48 is also operable to fully energize the heater 24 when the temperature of the steam 39 near the temperature sensor 46 falls below a set point during the heating cycle. Thus, the steam blanket has a temperature sensor 4
When the gas temperature drops below the 6 level, the temperature controller 48 energizes the heater 24 to generate additional hot steam. As a result, a relatively stable blanket or region of steam 39 is maintained above appliance 36, which ensures complete sterilization. The control circuit 30 initially emits a light in response to a temperature controller 48 responsive to the presence or absence of a vapor blanket at the level of the temperature sensor 46 and continues to emit light during the sterilization cycle by a light emitting diode (LED) 50 or similar indicating means. Contains.

Means are provided for removing vapors of entrained germicidal fluid 22 of air displaced from chamber 14 and expelled through ventilation passage 40. In the case of the embodiment shown in FIGS. 1, 2 and 4, such means are the cover 1
6 includes an L-shaped conduit 62 disposed within the filter unit 6 as a vent passage means. One end 6 of this conduit 62
4 communicates with the ventilation passage 40, and has an end 6 on the opposite side.
6 is connected to the atmosphere. The conduit 60 is filled with glass beads 68 and charcoal grains 70 or other suitable medium or media for removing and / or condensing the vapor of the sterilizing liquid 22 from the air stream passing through the conduit 62.

The vapor of the germicidal liquid 22 condenses as the instrument 36, tray 38 and chamber 14 cool after the germicidal cycle is completed as described in more detail below. The resulting reduction in pressure in chamber 14 causes atmospheric air to flow back through conduit 62. As this air passes through the charcoal 70 and the glass beads 68, the vapor and / or condensate trapped there is purged back into the chamber 14.

The control circuit 30 controls the heater 2 after the sterilization cycle is completed.
4 means for turning off or deactivating. Various suitable means, including conventional timing devices, can also be used for this purpose. In the illustrated embodiment,
The control circuit 30 includes conventional counting means 72. The counting means 72 receives and responds to the output signal from the temperature controller 48 and then counts the electrical energy cycle transmitted to the heater 24 and stops the flow of electrical energy to the heater 24 after a predetermined such cycle. It is ready to operate. The counting means 72 is a temperature controller 48.
Can be a conventional pulse clock generator operable to count the number of Hertz (HZ) cycles transmitted to the heater 24 after receiving the output signal from the heater 24 and turn off the heater 24 after a predetermined number of cycles. . Thus, a certain amount of electrical energy is transferred to the heater 24 during the sterilization cycle for each load, which ensures complete sterilization. If the power being delivered drops during use due to a large surge, the counter 72 measures this drop and activates the heater 24 for a longer period of time, thereby compensating for the drop in energy level.

The control circuit 30 controls the heater 24 upon completion of the sterilization cycle.
A light emitting diode (LED) 74, or other suitable indicating means, which emits light in response to the output signal from the counting means 72, for deactivating.

Due to the above control to keep the steam blanket at a predetermined level, the clean air 39 does not completely fill the chamber 14 as shown in FIG. 2 and the internal pressure is relatively low, ie at atmospheric pressure. Low pressure and 1.05kg / cm ² (15p.
sig) keep pressure not to exceed. Therefore, the sterilization device 10 does not have to be designed to withstand high internal pressures like most autoclave type sterilizers. Also, only a small amount of vapor is passed through the ventilation passage 40 to the chamber 1
4, which is only expelled from the ventilator 4 and is entrained in the airflow emitted through the ventilation passage 40.
The loss of steam from the sterilizing solution is minimized as it is removed by.

The control circuit 30 includes a cooling liquid control device 80. The controller 80 controls the heater 2 upon completion of the sterilization cycle.
In response to the output signal from the counting means 72 to deactivate the four, it is operable to energize an electrically operated cooling means, such as a fan 82 located at the rear of the housing 12. The fan 82 circulates air through the space 84 between the inner wall of the housing 12 and the outer wall of the chamber 14 to promote cooling of the chamber 14 and condensation of vapor. Housing 12 includes suitable air inlets and air outlets (not shown) to allow free circulation of ambient air across the outer wall of chamber 14.

When the vapor level falls below the position of the device 36, the latent heat rapidly causes the device to dry completely, thus leaving no residue. The inner wall of the chamber 14 is preferably configured to facilitate the discharge of condensed vapor collected therein to the reservoir 20.

Other suitable cooling means may be used. For example, a cooling liquid circulated through a coil disposed in the chamber 14 or surrounding the outer wall of the chamber 14 or disposed in the chamber 14 for performing electrostatic discharge in order to reduce latent heat and heat sensitivity. The grid structure can be mentioned.

The coolant controller 80 is also operable to deactivate the fan 82 when certain events occur. In the particular embodiment shown, the control circuit 30 controls the chamber 14
Includes a temperature sensor 86 for sensing the temperature of the gas within, and the coolant controller 80 controls the temperature to a predetermined level or set point at which the temperature sensor 86 will remove the device 36 without allowing large volumes of steam 39 to escape. Is deactivated in response to detecting that the fan 82 has fallen below. Other suitable means may be used to control the operating time of fan 82. For example, a temperature sensor that detects the temperature of the outer surface of the chamber 14 or 1
An example of the temperature control device has a timer set for setting a predetermined time on the order of 0 to 15 minutes. The control circuit 30
A light emitting diode (LED) 8 that emits light in response to an output signal from the coolant control device 80 to turn off the fan 82.
8 or other suitable indicating means.

The various components of control circuit 30 are shown schematically and external to housing 12 for clarity. In fact, all components except temperature sensors 46 and 86 (and power supply 28 if the device is configured to be plugged into an electrical outlet) are
Located in front of the two and housed in a control compartment 90 that includes a control panel 92. Various operating switches and a light emitting indicator are mounted on the control panel 92.

The operating principle will be described. First, the instrument 36 is washed with water and soap or an ultrasonic device, and placed in a tray 38. After closing the cover 16, the starter switch 32, which is preferably a momentary push button, is moved to the on position, thereby initiating the sterilization cycle. Then, heater 2
4 is energized to heat the liquid 22 to a boil and the indicator 34 illuminates. The indicator 50 is the temperature sensor 4
It emits light when 6 detects the presence or absence of a vapor blanket on the appliance 36 and continues to emit light during the sterilization cycle. Indicator 34 flashes repeatedly when heater 24 is energized or de-energized during the sterilization cycle as the vapor blanket crosses and below temperature sensor 46, as described above. The sterilization cycle is counting means 7
Upon completion as determined by 2, both indicators 34 and 50 are turned off and indicator 7
4 emits light. When the fan 82 is energized, the indicator 88 emits light, and the cooling liquid controller 80 causes the fan 82 to emit light.
When de-energized, both indicators 74 and 88 are turned off.

When the sterilization cycle is complete, almost no pressure builds up in chamber 14 at any time, and cover 16 can be opened and instrument 36 removed. However, it is preferred that the cover 16 not be opened until the fan 82 is turned off to prevent loss of vapor still remaining in the chamber 14.

FIG. 5 shows an alternative embodiment of the vapor recovery means. This embodiment shows a generally U-shaped conduit or tube 102.
The filter / condenser device 100 is included as a ventilation path unit including the. This tube 102 has one end 10
4 communicates with the ventilation passage 40, and the other end 106 communicates with the atmosphere. The lower portion 108 of the tube 102 acts as a liquid trap for the condensed vapor of the germicidal liquid 22 removed from the air stream passing through the tube 102. Porous filters 110 and 112 are arranged in the tubes 102 upstream and downstream of the liquid trap portion 108, and porous filters 110 and 112 are arranged in the tube 102 downstream of the filter 112.
A glass bead 114 and charcoal grain 116 packed in the tube 102 downstream of the filter 112 function to help remove and / or condense steam from the air stream flowing through the tube 102 during the sterilization cycle. .

At the completion of the sterilization cycle, air flows back through the tube 102 and the chamber 14 is cooled as described above. The sterilizing liquid 22 collected in the liquid trap 108 is supplied to the ventilation passage 40.
Through the chamber 14 or the liquid trap portion 108.
And directly to reservoir 22 via conduit 118 (shown partially in dashed lines) in fluid communication with reservoir 20.

FIG. 6 shows another alternative embodiment of the vapor recovery means. This embodiment includes an inflatable collapsible member 120 disposed in a chamber 122 having an inlet 124 defined inside the cover 16a and in communication with the ventilation passage 40. The bladder 120 has an inflatable volume large enough to collect all the air displaced from the chamber 114 by the steam blanket during the sterilization cycle.
The cover chamber 122 is shielded from the atmosphere,
The bladder 120 inflates when it receives the displaced air containing the entrained vapor of sterilizing liquid 22.

As the chamber 14 cools and the vapors therein begin to condense after the completion of the sterilization cycle, the pressure drop in the chamber 14 causes the air and vapors in the bladder 122 to move to the chamber 14.
Back into the bag and the bag 120 is finally collapsed into its collapsed state. In order to ensure a balanced pressure condition between chamber 14 and cover chamber 122, cover chamber 122
It is also possible to arrange the check valve 130 in the inside.

[Brief description of drawings]

FIG. 1 is a perspective partial schematic view of a sterilization device embodying the present invention. 2 is an enlarged side elevational view of the sterilization device shown in FIG. 1 and a schematic diagram of an electrical control circuit. FIG. 3 is an enlarged perspective view of a heater of the sterilization device shown in FIG. FIG. 4 shows the first
4 is an enlarged schematic view of the vapor recovery means about line 4-4 in the figure. Fifth
The figure is an enlarged schematic view of an alternative device of the vapor recovery means. Figure 6 shows
4 is an enlarged schematic view of another alternative device for the vapor recovery means. 10 ... Sterilization device, 12 ... Housing 14 ... Inner chamber, 16 ... Revised opening 18 ... Peripheral gasket, 20 ... Reservoir 22 ... Sterilization liquid, 24 ... Electric heater 26 ... Heating element, 28 ... Electric power source 30 Electric control circuit 32 Starter switch 34 Light emitting diode 36 Dental instrument 38 Perforated tray 39 Vapor 40 Ventilation passage 46 Temperature sensor 48 ... Temperature control device, 50 ... Light emitting diode 60 ... Filter device, 62 ... L-shaped conduit tube 68 ... Glass bead, 70 ... Charcoal grain 72 ... Counting means, 74 ... Light emitting diode 80 ... Cooling Liquid control device, 82 ... Juan 86 ... Temperature sensor, 88 ... Light emitting diode 90 ... Control compartment, 92 ... Control panel 100 ... Filter / Capacitor device, 102 ... U-shaped conduit, 108 ... Liquid trap part 110, 112 ... Porous filter, 114 ... Glass beads, 116 ... Charcoal grain 118 ... Conduit, 120 ... Expandable and foldable Member, 122 ... Chamber, 130 ... Check valve

Claims (12)

[Claims] 1. A sterilizer having a housing (12) having an openable and accessible enclosure and defining an internal chamber (14) having an upper portion and a lower portion, and microorganisms harmful to the human body. A substantially non-toxic and substantially inert vaporizable germicide having a boiling point high enough to kill (22)
A reservoir means (20) arranged in the lower part of the chamber (14) for accommodating the sterilizing liquid, and the rising blanket for heating and vaporizing the sterilizing liquid and substantially saturated with the sterilizing liquid. Electric heating means (24) for supplying (39), and said reservoir means (2) for supporting the article (36) to be sterilized and for passing the ascending vapors in contact with said article (2).
0) a supporting means (38) arranged above the electrical energy source (28) and an electric control circuit means (30) connected to the heating means (24), said heating means (24). Electrical control circuit means (30) for controlling the operation of the chamber and thereby controlling the level of vapor in the chamber, the control circuit means (30) including the support means (38) and Articles supported on it (3
6), which is arranged above the detection means (46) for detecting the presence or absence of the blanket (39) having a relatively high vapor density, and the detection means (46) and the heating means (24) are electrically interconnected. Means (48), said detection means (4
6) enables the flow of electrical energy to the heating means (24) in response to detecting the absence of the steam blanket, and further the article when the detecting means detects the presence of the steam blanket. The interconnecting means (48) for stopping the flow of electrical energy to the heating means after a predetermined period of time sufficient to sterilize the device, and an opening to the atmosphere throughout the normal operation of the device. Venting means (60, 100) for providing and discharging the air displaced by the ascending vapor blanket from the chamber into the atmosphere, the inlet communicating with the chamber above the sensing means (46). (40, 104)
And a vent passage means (60, 100) having an outlet (66, 106) communicating with the atmosphere. 2. Means (68, 70; 1) for recovering sterilizing liquid vapor disposed in the air passage means (60, 100) and entrained in an air stream passing through the entire air passage means.
14. A device as claimed in claim 1, characterized in that 3. The vapor recovery means (68, 70; 114,
116) is configured such that after the end of the sterilization cycle, the condensed vapor is returned to the reservoir means by backflowing atmospheric air through the vent passage means in response to cooling of the chamber. The device according to claim 2, characterized in that 4. The vapor passage means is a generally U-shaped conduit for forming a liquid trap (108) for the condensed vapor, the vapor recovery means (68, 70; 114, 116). An apparatus according to claim 3, wherein said device comprises a porous medium, said medium for entraining and removing vapors of sterilizing liquid from an air stream passing through said medium. 5. The apparatus according to claim 1, wherein the heating means is immersed in the sterilizing solution in direct contact with the sterilizing solution. 6. The heating means includes a heating element (26) made of a positive temperature coefficient thermistor material that provides a substantially constant surface temperature despite variations in the electrical energy supplied thereto. A device according to claim 5, characterized in that 7. The steam detecting means (46) is a temperature detecting means (46).
The device according to paragraph. 8. The control circuit means (30) is a counting means (7).
2), the counting means (72) counts the number of cycles of electrical energy transferred to the heating means (24) after the detection means (46) detects the presence of a steam blanket (39), and An apparatus as claimed in claim 1, characterized in that the flow of electrical energy to the heating means is stopped after counting a predetermined number of the cycles. 9. An electrically operated cooling means (82) and said control circuit means (30) responsive to stopping the flow of electrical energy to said heating means (24) upon completion of a sterilization cycle. Device according to claim 1, characterized in that it comprises means (80) for energizing said cooling means (82). 10. A reservoir for containing a cover (16), a top portion and a substantially non-toxic and substantially inert vaporizable germicide having a boiling point high enough to kill microorganisms harmful to the human body. Vent passage means (60, 100) having a lower portion containing (20), an inlet (40, 104) communicating with the upper portion of the chamber and an outlet (66, 106) communicating with the atmosphere throughout the sterilization period. Supplying a chamber (14) containing the liquid, placing an article (36) to be sterilized in the chamber (14) at a position above the reservoir (20), and heating the sterilizing solution (22). To vaporize, and the ascending blanket (3) of the substantially saturated vapor of the sterilizing solution.
9) supplying the vapor blanket in contact with the substance to be sterilized and displaced to replace the air in the chamber to expel the air to the atmosphere through the venting means. The step of supplying the steam blanket (39) and the relatively high density of the steam in the chamber (14) above the article (36) to be sterilized and below the inlet of the vent passage means. Blanket (39)
And (46) measuring the presence or absence of the presence of a steam blanket (39) at the location, and then measuring the presence of the steam blanket (39) at the location for a predetermined period of time sufficient exposure of the article to steam for sterilization. A method for sterilizing articles such as surgical instruments and dentistry instruments, which comprises a step of continuing heating and a step of stopping the heating of the sterilizing solution after the predetermined period. 11. The sterilizing solution (22) comprises at least about 1 part.
The method according to claim 10, which is a fluorocarbon liquid having a boiling point of 00 ° C. 12. The method according to claim 1, wherein the boiling point of the fluorocarbon liquid is at least about 150 ° C.
The method according to item 1.