Patent ID: 12233194

While the disclosure is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the disclosure to the particular embodiments described. On the contrary, the disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the appended claims.

DETAILED DESCRIPTION

FIG.1is a diagram illustrating a system20for reducing the aerosol emitted from a heater/cooler unit22having an internal space22a, according to various embodiments of the disclosure. A variety of heater/cooler units22are well known to the skilled artisan. Heater/cooler units generally include an internal space22ahaving one or more fluid tanks23or containers coupled to a heating and/or cooling source. Internal space22aincludes any space in the heater/cooler unit22within which an aerosol may be present. In some embodiments, internal space22aincludes any space within the outer surfaces of the heater/cooler unit22. In some embodiments, internal space22aincludes an internal space within the one or more fluid tanks23. Additionally, heater/cooler units22typically include a control system for controlling the desired fluid temperature and flow of the fluid from the tank23(or tanks) to the desired component or location. Most typically, the fluid used in the heater/cooler unit22is water, often with an added disinfectant. Additional details of heater/cooler units are described in U.S. Pat. No. 9,259,523, which is hereby incorporated by reference.

The system20further includes tubing24and a filter unit26. The filter unit26is fluidly coupled to the heater/cooler unit22and to a vacuum source28by the tubing24. In some embodiments, the tubing24is configured to be detachably coupled to at least one of the filter unit26, the heater/cooler unit22, and the vacuum source28. In some embodiments, the filter unit26is configured to be detachably coupled to at least one of the tubing24, the heater/cooler unit22, and the vacuum source28. In some embodiments, at least one of the tubing24and the filter unit26is disposable, such that contamination from the disposable part(s) is discarded and build-up of contamination is prevented. In some embodiments, both the tubing and the filter unit are disposable, either as individual items or together as part of a single disposable unit. In still further embodiments, a sterile disposable unit having an aerosol filter unit and tubing may be provided in a sealed container.

Referring again toFIG.1, the filter unit26is coupled to the vacuum source28by a first tube24aof the tubing24and to an internal space22aof the heater/cooler unit22by a second tube24bof the tubing24. In some embodiments, the vacuum source28is a house vacuum provided by a medical facility, such as through a wall vacuum socket in an operating room. In some embodiments, the vacuum source28is a non-disposable vacuum source that can be provided with the system20including the tubing24and the filter unit26. In some embodiments, the vacuum source28is a disposable vacuum unit that is provided as a part of a disposable unit including the filter unit26and the tubing24. In some embodiments, the second tube24bis coupled to an existing overflow port30on the heater/cooler unit28, which is fluidly coupled to the internal space22aof the heater/cooler unit28. The existing overflow port30is provided for fluid overflow of one or more of the tanks23in the internal space22aof heater/cooler unit22. Connecting the second tube24bto an existing overflow port30enables the tubing24and the filter unit26to be retrofit to an existing heater/cooler unit22. In some embodiments, the tank23is closed, such that fluid in the tank23is not open to the internal space22aabove the tank23, instead the tank23is enclosed such as with a lid, and the overflow port30is coupled directly to the tank23. In other embodiments, the tank23or fluid in the tank23is open to the internal space22aabove the tank23, and the overflow port30is coupled to the internal space22aabove the tank23. In some embodiments, the second tube24bis coupled to the heater/cooler unit28and fluidly coupled to the internal space22aof the heater/cooler unit28, with or without being coupled to an overflow port, such as the overflow port30. In some embodiments, the tank23is closed, such that fluid in the tank23is not open to the internal space22aabove the tank23, instead the tank23is enclosed such as with a lid, and the second tube24bis coupled directly to the tank23, with or without being coupled to an overflow port, such as the overflow port30. In other embodiments, the tank23or fluid in the tank23is open to the internal space22aabove the tank23, and the second tube24bis coupled to the internal space22aabove the tank23, with or without being coupled to an overflow port, such as the overflow port30.

In some embodiments, a disposable aerosol removal kits for coupling to an existing overflow port30on a heater/cooler unit22may include a filter unit26and tubing24. Optionally, a disposable vacuum element may also be included in the disposable kit. The disposable kit may be provided as a sterile unit in a sealed container.

In operation, the vacuum source28is activated to provide a vacuum or a negative air pressure relative to the external air pressure to the filter unit26. In some embodiments, the vacuum source28is manually activated. In some embodiments, the vacuum source28includes an electronic control circuit32that activates the vacuum source28for a limited duration to remove the aerosol from the heater/cooler unit22. In some embodiments, the vacuum source28includes an electronic control circuit32that activates the vacuum source28for at least 10 minutes to remove the aerosol from the heater/cooler unit22. In some embodiments, the vacuum source28includes an electronic control circuit32that activates the vacuum source28whenever the heater/cooler unit22is activated to remove the aerosol from the internal space22aof the heater/cooler unit22. In some embodiments, the vacuum source28is turned on before the heater/cooler unit22is turned on. In some embodiments, the vacuum source28is turned on at the same time the heater/cooler unit22is turned on.

In some embodiments, the heater/cooler unit22includes a pressure sensor25to determine the pressure in at least one of the internal space22aand the one or more tanks23. In some embodiments, the pressure sensor25is communicatively coupled to the electronic control circuit32, such as by wire or wirelessly. In some embodiments, electronic control circuit32activates the vacuum source28based on a signal from the pressure sensor25indicating that the pressure equals or exceeds a pressure where aerosols may escape from the heater/cooler unit22and into the environment. In some embodiments, electronic control circuit32activates the vacuum source28based on a signal from the pressure sensor25indicating that the pressure equals or exceeds the current ambient pressure, also referred to as zero herein. In some embodiments, electronic control circuit32activates the vacuum source28based on a signal from the pressure sensor25indicating that the pressure equals or exceeds the current atmospheric pressure. In some embodiments, electronic control circuit32activates the vacuum source28based on a signal from the pressure sensor25indicating the pressure equals or exceeds a pressure threshold. In some embodiments, the pressure threshold is a factory preset threshold. In some embodiments, the pressure threshold is set by an operator and/or the electronic control circuit32. In some embodiments, the pressure threshold is zero or the current ambient pressure. In some embodiments, electronic control circuit32activates the vacuum source28for a predetermined duration. In some embodiments, the electronic control circuit32activates the vacuum source28until the signal from the pressure sensor25indicates the pressure has been reduced, such that the danger of aerosols escaping has been eliminated. In some embodiments, the electronic control circuit32activates the vacuum source28until the signal from the pressure sensor25indicates the pressure is below the pressure threshold. In some embodiments, the electronic control circuit32activates the vacuum source28in response to the signal from the pressure sensor25indicating the pressure is a non-negative pressure, such as equal to or greater than the current ambient pressure. In some embodiments, the electronic control circuit32activates the vacuum source28based on the signal from the pressure sensor25to maintain a negative pressure, such as less than the current ambient pressure, in at least one of the internal space22aand the one or more tanks23to prevent aerosols from escaping from the heater/cooler unit22and into the surrounding environment.

In some embodiments, the heater/cooler unit22includes a sensor34to determine an aerosols concentration in the internal space22aof the heater/cooler unit. In some embodiments, electronic control circuit32activates the vacuum source28based on a signal from sensor34indicating that any aerosols have been detected. In some embodiments, electronic control circuit32activates the vacuum source28based on a signal from sensor34indicating an aerosols concentration exceeding an aerosol concentration threshold. In some embodiments, the aerosol concentration threshold is a factory preset threshold. In some embodiments, the aerosol concentration threshold is set by an operator. In some embodiments, electronic control circuit32activates the vacuum source28for a predetermined duration. In some embodiments, the electronic control circuit32activates the vacuum source28until the signal from sensor34indicates all aerosols have been eliminated. In some embodiments, the electronic control circuit32activates the vacuum source28until the signal from sensor34indicates an aerosols concentration below a threshold. In some embodiments, sensor34may be located outside the heater/cooler unit22, such as in tubing24bconnecting heater/cooler22and filter unit26.

The filter unit26includes a filter container or bottle and the negative air pressure is provided to the filter container to suction aerosol from the heater/cooler unit22into the filter container. This eliminates and/or reduces the amount of aerosol that escapes from the heater/cooler unit22and diffuses into the ambient air of the operating theatre. In some embodiments, the filter unit26includes an antibacterial filter element. In some embodiments, the filter unit26includes an antibacterial filter element that includes at least one of a hydrophobic filter element and a hydrophilic filter element. In some embodiments, systems of the present disclosure, such as system20, are capable of substantially removing all aerosols and/or bacteria from the system, and prevent any aerosol or bacteria from entering the operating room environment. In some embodiments, systems of the present disclosure, such as system20, reduce the aerosol emitted from the heater/cooler unit22by at least 95%.

FIGS.2-4are diagrams illustrating the filter unit26, according to various embodiments of the disclosure. The filter unit26receives and filters the aerosol received from the internal space (or the tank) of the heater/cooler unit22. The filter unit26prevents contaminants or microorganisms, such as bacteria, from entering the vacuum source28.

FIG.2is a diagram illustrating the filter unit26, according to some embodiments of the disclosure. The filter unit26includes a filter cap40and a filter container42. The filter cap40is or can be attached to the filter container42in an air tight connection to allow for creating a negative air pressure in the filter container42. In some embodiments, the filter cap40is attached to the filter container42in an air tight connection to prevent captured aerosol from escaping into the ambient air of the operating theatre. In some embodiments, the filter cap40is detachably or removably attached to the filter container42, for example, by a snap-fit engagement or a threaded connection. In some embodiments, the filter cap40is fixedly attached to the filter container42, such that the filter cap40cannot be easily removed from the filter container42. In some embodiments, the filter cap40is integrally formed with the filter container42and cannot be removed.

FIG.3is a diagram illustrating a top view of the filter cap40, according to embodiments of the disclosure. The filter cap40includes a first connection44and a second connection46for connecting the tubing24to the filter cap40. The first connection44is used to connect the filter cap40to the vacuum source28, and the second connection46is used to connect the filter cap40to the heater/cooler unit22. In other embodiments, the first connection44is used to connect the filter cap40to the heater/cooler unit22, and the second connection46is used to connect the filter cap40to the vacuum source28. In the embodiment ofFIGS.2and3, the first connection44and the second connection46are right angle or elbow connections. In other embodiments, however, one or both of the first and second connections44and46can be differently shaped connections, such as straight, vertical connections.

In one embodiment, the filter cap40also includes a pour spout48, and a tandem port50. The pour spout48is configured to be used for emptying the filter container42or connecting the filter unit26to a specimen collector. The tandem port50is configured to be used to connect multiple filters, such as a second filter unit (not shown), in series or parallel with filter unit26, to collect and filter aerosol. In some embodiments, the filter cap40further includes attached port caps52aand52bfor capping the first connection44and the second connection46, respectively. In some embodiments, port cap52cis provided for capping the pour spout48, and port cap52dis provided for capping the tandem port50. The port caps52a-52dcan be used to eliminate cap loss and allow for quick and secure capping of the filter unit26.

In some embodiments, the filter cap40includes an antibacterial filter element. In some embodiments, the filter cap40includes an antibacterial filter element that includes at least one of a hydrophobic filter element and a hydrophilic filter element.

In some embodiments, the antibacterial filter element includes a hydrophobic filter element54, attached below the first connection44and to the underside of the filter cap40. The filter unit26filters the aerosol received from the heater/cooler unit22at or near the first connection44, which is coupled to the vacuum source28. The filter unit26captures contaminants in the hydrophobic filter element54, and prevents contaminants, such as bacteria, from entering the vacuum source28. In some embodiments, the filter unit26filters the aerosol received from the heater/cooler unit22at or near the second connection46, which is coupled to the heater/cooler unit22, to capture contaminants in the hydrophobic filter54and prevent contaminants, such as bacteria, from entering the filter container42. In some embodiments, the filter unit26includes a hydrophobic filter54configured to filter up to 99.99 percent of aerosolized micro-organisms and particulate matter in the aerosol received from the heater/cooler unit22. In some embodiments, the antibacterial filter element includes a hydrophilic filter element.

FIG.4is a diagram illustrating a hydrophobic filter element54, according to various embodiments of the disclosure. The hydrophobic filter element54includes a hydrophobic filter stage56, a breathing screen58, a pre-filter stage60, and a housing62. The hydrophobic filter stage56, breathing screen58, and pre-filter stage60are housed in the housing62, which protects these filter components from splash and foam. The breathing screen58separates the hydrophobic filter stage56from the pre-filter stage60. In one embodiment, the hydrophobic filter stage56is configured to filter up to 99.99 percent of aerosolized micro-organisms and particulate matter. In some embodiments, the hydrophobic filter element54includes a hydrophobic shut-off filter that closes the suction port or stops vacuum flow when contacted by fluid, such as fluid suctioned into the container, and the breathing screen58separates the hydrophobic filter stage56from the pre-filter stage60to improve suction while reducing premature shut-off. In some embodiments the hydrophobic filter element54includes a hydrophobic shut-off filter that closes the suction port or stops vacuum flow when contacted by fluid, such as fluid suctioned into the container, and the pre-filter stage60protects the hydrophobic filter stage56from erroneous shut-off due to laser or electrocautery smoke.

In some embodiments, the hydrophobic filter stage56filters the aerosol received from the heater/cooler unit22at or near the first connection44, which is coupled to the vacuum source28. In some embodiments, the hydrophobic filter56filters the aerosol received from the heater/cooler unit22at or near the second connection46, which is coupled to the heater/cooler unit22. In still further embodiments, two hydrophobic filter stages56are provided, one at or near each of the first and second connections44and46, respectively.

FIG.5is a diagram illustrating a system100for reducing the aerosol emitted from a heater/cooler unit102having an internal space102a, according to some embodiments of the disclosure. The system100includes tubing104, a filter106, and a sensor108. In some embodiments, the tubing104is similar to the tubing24. In some embodiments, the filter106is similar to the filter unit26. Also, in some embodiments, the heater/cooler unit102is similar to the heater/cooler unit22.

Vacuum source110includes a vacuum source unit112and a vacuum valve114for providing a vacuum or negative air pressure relative to the external air pressure to the filter106. In some embodiments, the vacuum source110including the vacuum source unit112includes the house vacuum of the medical facility. In some embodiments, the vacuum source unit112is a non-disposable vacuum source unit. In some embodiments, the vacuum source unit112is a disposable vacuum source unit that may be discarded.

The filter106is fluidly coupled to the vacuum valve114by the tubing104and to the sensor108by the tubing104. The vacuum valve114is fluidly coupled to the vacuum source unit112by the tubing104, and the sensor108is fluidly coupled to the internal space102a(or the tank) of the heater/cooler unit102by the tubing104. In some embodiments, the tubing104is configured to be detachably coupled to at least one of the filter106, the vacuum valve114, the sensor108, the heater/cooler unit102, and the vacuum source unit112. In some embodiments, the filter106is configured to be detachably coupled to at least one of the tubing104, the vacuum valve114, the sensor108, the heater/cooler unit102, and the vacuum source unit112. In some embodiments, at least one of the tubing104, the filter106, the vacuum source unit112, the vacuum valve114, and the sensor108is disposable, such that contamination from the disposable part(s) is discarded and build-up of contamination is prevented.

The filter106is fluidly coupled to the vacuum valve114by a first tube104aand to the sensor108by a second tube104b. The vacuum valve114is fluidly coupled to the vacuum source unit112by a third tube104cand the sensor108is fluidly coupled to the internal space102a(or the tank) of the heater/cooler unit102by a fourth tube104d. In some embodiments, the vacuum source unit112is the house vacuum provided by the medical facility, such as through a wall vacuum socket. In some embodiments, the vacuum source unit112is a standalone, external vacuum source that can be provided with the system100. In some embodiments, the fourth tube104dis coupled to an existing overflow port116on the heater/cooler unit102, where the existing overflow port116is provided for fluid overflow of one or more of the tanks in the heater/cooler unit102. Connecting the fourth tube104dto an existing overflow port116enables the system100to be retrofit to an existing heater/cooler unit102.

The sensor108is configured to detect aerosols and/or contaminants, such as bacteria, in the tubing104, suctioned from the internal space102a(or the tank) of the heater/cooler unit102. The sensor108is communicatively coupled to the vacuum valve114via communications path118. In some embodiments, the sensor108is installed in the internal space102a(or the tank) of the heater/cooler unit102(dashed arrow), such as in or near the overflow port116to sense or detect aerosols and/or contaminants in the internal space102a(or the tank) of the heater/cooler unit102.

The sensor108includes control electronics120, such as a processor, configured to provide an output signal in response to detecting aerosols and/or contaminants. In some embodiments, the sensor108activates the vacuum valve114via the output signal to open the vacuum valve114and provide a vacuum or negative air pressure relative to the external air pressure from the vacuum source unit112to the filter106in response to detecting a contaminant or an aerosol. In some embodiments, the sensor108is configured to activate the vacuum valve114via the output signal to open the vacuum valve114for a limited time to provide the vacuum or negative air pressure relative to the external air pressure to the filter106in response to detecting a contaminant or an aerosol. In some embodiments, the sensor108is configured to activate the vacuum valve114via the output signal to open the vacuum valve114for less than 10 minutes to provide the vacuum or negative air pressure relative to the external air pressure to the filter106in response to detecting a contaminant or an aerosol. In some embodiments, the sensor108activates the vacuum valve114via the output signal for as long as an aerosol condition is detected. In some embodiments, the sensor108activates the vacuum valve114via the output signal for as long as an aerosol concentration exceeds an aerosol concentration threshold.

In some embodiments, the sensor108activates an alarm or display on the sensor108via the output signal in response to detecting a contaminant or an aerosol. In some embodiments, the system100can be provided without a vacuum valve114, such that the vacuum source110including the vacuum source unit112is manually activated to provide a vacuum or negative air pressure relative to the external air pressure to the filter106, such as in response to an alarm or display on the sensor108indicating the presence of a contaminant, aerosols, or an aerosol concentration exceeding an aerosol concentration threshold.

In some embodiments, the system100can be provided without a vacuum valve114and the sensor108is communicatively coupled to the vacuum source unit112via communications path122(dashed line), such that the sensor108activates the vacuum source unit112directly to provide a vacuum or negative air pressure relative to the external air pressure to the filter106in response to sensing or detecting a contaminant, an aerosol, or an aerosol concentration. In some embodiments, the system100can be provided without a vacuum valve114and the sensor108is communicatively coupled to the vacuum source unit112via communications path122(dashed line), such that the sensor108activates the vacuum source unit112directly for a limited time to provide a vacuum or negative air pressure relative to the external air pressure to the filter106in response to sensing or detecting a contaminant or an aerosol. In some embodiments, the sensor108activates the vacuum source unit112directly to provide a vacuum or negative air pressure to the filter106for a duration defined by the time that the contaminant, aerosol, or aerosol concentration remains detected, i.e., for as long as an undesired sensed condition is detected.

In operation, the vacuum source110is activated to provide a vacuum or negative air pressure relative to the external air pressure to the filter106. In some embodiments, the vacuum source110is activated via the sensor108. In some embodiments, the vacuum source110is activated manually.

In some embodiments, the vacuum source110includes an electronic control unit124, which is one or more of electronic control unit124ain vacuum source unit112and electronic control unit124bin vacuum valve114. In some embodiments, the electronic control circuit124activates the vacuum source110for a limited time to remove the aerosol from the heater/cooler unit102. In some embodiments, the electronic control circuit124activates the vacuum source110for a limited time when an operational condition of the heater/cooler unit102indicates a likelihood of aerosol production. In one embodiment, the operational condition indicating a likelihood of aerosol production includes activating a heating source within the heater/cooler unit

102. In some embodiments, the electronic control circuit124activates the vacuum source110when a contaminant aerosol, or aerosol concentration is detected for as long as the detection condition remains present. In some embodiments, the electronic control unit124is in communication with the heater/cooler unit102, such as by a wire (not shown for clarity) or wireless communications. In some embodiments, the vacuum source110is turned on before the heater/cooler unit102is turned on. In some embodiments, the vacuum source110is turned on at the same time the heater/cooler unit102is turned on.

The filter106includes a filter container and the negative air pressure is provided to the filter container to suction aerosol from the heater/cooler unit102into the filter container. This eliminates and/or reduces the amount of aerosol that escapes from the heater/cooler unit102and the amount of aerosol that diffuses into the ambient air of the operating theatre. In some embodiments, the system20reduces the aerosol emitted from the heater/cooler unit102by at least 95%.

FIG.6is a diagram illustrating a method of reducing aerosol emitted from a heater/cooler unit, according to embodiments of the disclosure. Each of the systems described in this disclosure, including system20ofFIG.1and system100ofFIG.5, can be used to provide the method.

At200, the method includes fluidly coupling a filter to a vacuum source and to an internal space (or a tank) of a heater/cooler unit by using tubing. In some embodiments, the filter includes a hydrophobic filter configured to filter up to 99.99 percent of aerosolized micro-organisms and particulate matter in the aerosol received from the heater/cooler unit. In some embodiments, this coupling includes one or more tubes and/or devices coupled between the filter and each of the vacuum source and the heater cooler unit. In one embodiment, a sensor for detecting aerosol is provided in the tubing coupling the heater/cooler unit and the filter. In one embodiment, a vacuum valve is provided in the tubing coupling the vacuum source and the filter.

In some embodiments, portions of the systems20and100are disposable, where ease of attachment and detachment provides for easy disposability. In some embodiments, the tubing is detachably coupled, such that it is configured to be easily attached and detached, to one or more of the filter, the vacuum source, and the heater/cooler unit. In some embodiments, the filter is detachably coupled, such that it is configured to be easily attached and detached, to one or more of the tubing, the vacuum source, and the heater/cooler unit. In some embodiments, at least some of the tubing is disposable, such that at least some of the tubing can be disposed of to reduce contamination and build-up of contamination in the tubing. In some embodiments, the filter is disposable, such that the filter can be disposed of to reduce contamination and build-up of contamination in the filter. In some embodiments, a disposable unit is provided that includes the filter and tubing to couple the filter to each of the heater/cooler unit and the vacuum source. In a further embodiment, a disposable unit is provided that includes the filter, a vacuum source, and tubing to couple the filter to the heater/cooler unit. Optionally, additional tubing may be provided to couple the filter to the vacuum source.

Referring again toFIG.6, at202, the method includes activating the vacuum source for at least a limited time to provide negative air pressure relative to external air pressure in the filter to suction the aerosol from the internal space (or the tank) of the heater/cooler unit into the filter. In some embodiments, the aerosol emitted from the heater/cooler unit is eliminated. In some embodiments, the aerosol emitted from the heater/cooler unit is reduced by at least 95%.

In some embodiments (not shown inFIG.6), the method includes sensing or detecting at least one of a contaminant such as bacteria, an aerosol, and an aerosol concentration, via a sensor. In one embodiment, the sensor is provided in the internal space (or the tank) of the heater/cooler unit. In one embodiment, the sensor is provided in the tubing coupling the heater/cooler and the filter. In some embodiments, the sensor can be configured to provide at least one of an alarm or display in response to the detecting of the at least one of the contaminant, the aerosol, and the aerosol concentration, and activating the vacuum source to provide a vacuum in response to the detecting of the at least one of the contaminant, aerosol, and aerosol concentration.

FIG.7is a graph illustrating aerosol particle count near the air fan over time for a heater/cooler system that does not include an aerosol elimination/reduction system described in this disclosure (indicated at300) and a heater/cooler system that does include an aerosol elimination/reduction system described in this disclosure (indicated at302). The aerosol was measured near the fan of the heater/cooler unit to measure the maximum value expected for the aerosol dispersed into the operating room environment, but similar data could be obtained by measuring at different locations. The vertical axis at304depicts the aerosol particle count as reflected in lines300and302). The temperature of the fluid in the heater/cooler unit is indicated at line310, as reflected on vertical axis306in degrees centigrade (C). The horizontal axis at

308depicts time in minutes. Aerosols are most heavily produced during the heater/cooler heating phase, where the temperature of the fluid in the heater/cooler unit is graphed at310.

At312, the heater/cooler unit has not yet started heating the heater/cooler fluid, which may be water, and the temperature of the fluid is about 20 C. At314, at the five minute mark, the heater/cooler unit begins to heat the fluid from 20 C to about 41 C at316, between the 10 and 11 minute marks. During this five to six minute heating time, the heater/cooler unit most heavily emits aerosols near the air fan.

The aerosol particle count measured in the air exiting the fan of the heater/cooler unit that does not have an attached aerosol reduction system300is at a particle count of about zero or below zero at318. The particle count begins to increase almost immediately at320, after the heater/cooler unit begins to heat the fluid at the five minute mark. The aerosol particle count increases to a maximum level of about 4800-4900 particles at322, between the 11 and 12 minute marks. Thereafter, the particle count decreases at324to a relatively stable level of about 500 particles at326, where it remains for the rest of the time.

In contrast, the aerosol particle count measured in the air exiting the fan of the heater/cooler unit that has an attached and activated aerosol reduction system is at a particle count of about −500 or below at330. This particle count increases slightly at332, to a particle count of about zero, which is about the same as the initial particle count measured in the air exiting the fan of the heater/cooler unit that does not have an attached aerosol reduction system at318. Thereafter, the particle count remains at about zero for the remainder of the time, decreasing slightly at the 30 minute mark at334.

The difference in the graph of the aerosol particle count emitted by the heater/cooler system that does not include an aerosol reduction system (line300) and the graph of the aerosol particle count emitted by the heater/cooler system that does include an aerosol reduction system (line302), exemplifies the improvement achieved by the aerosol reduction system described in this disclosure.

FIG.8is a graph illustrating aerosol particle mass near the air fan over time for a heater/cooler system that does not include an aerosol elimination/reduction system described in this disclosure (line400) and a heater/cooler system that does include an aerosol elimination/reduction system described in this disclosure (line402). The aerosol was measured near the fan of the heater/cooler unit to measure the maximum value expected for the aerosol dispersed into the operating room environment, but similar data could be obtained by measuring at different locations. The vertical axis at404depicts the aerosol particle mass in micrograms per meter cubed (ug/m3). The temperature of the fluid in the heater/cooler unit is indicated at line410, as reflected on the vertical axis at406in degrees centigrade (C). The horizontal axis at408depicts time in minutes. Aerosols are most heavily produced during the heater/cooler heating phase, where the temperature of the fluid in the heater/cooler unit is graphed at line410.

At412, the heater/cooler unit has not yet started heating the heater/cooler fluid, which may be water, and the temperature of the fluid is about 20 C. At414, at the five minute mark, the heater/cooler unit begins to heat the fluid from 20 C to about 41 C at416, between the 10 and 11 minute marks. During this five to six minute heating time, the heater/cooler unit most heavily emits aerosols into the air.

The aerosol particle mass in the air exiting the fan of the heater/cooler unit that does not have an attached aerosol reduction system is at a particle mass of about zero at418. The particle mass begins to increase at420at the nine and a half minute mark, after the heater/cooler unit begins to heat the fluid at the five minute mark. The aerosol particle mass increases to a maximum level of about 110 at422between the 11 and 12 minute marks. Thereafter, the particle mass decreases at424to a relatively stable level of about zero at426, where it remains for the rest of the time.

In contrast, the aerosol particle mass in the air exiting the fan of the heater/cooler unit that has an attached and activated aerosol reduction system is at a particle mass of about zero at430and remains at about zero for the remainder of the time at432.

The difference in the graph of the aerosol particle mass emitted by the heater/cooler system that does not include an aerosol reduction system (line400) and the graph of the aerosol particle mass emitted by the heater/cooler system that does include an aerosol reduction system (line402), exemplifies the improvement achieved by the aerosol reduction system described in this disclosure.

Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present disclosure. For example, while the embodiments described above refer to particular features, the scope of this disclosure also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present disclosure is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.