Patent Description:
Clean rooms found in manufacturing, research, and other facilities are typically classified into two broad categories based on the static air pressure inside the rooms relative to atmospheric pressure and/or the air pressure in spaces adjacent the clean rooms. A positive air pressure room is maintained at an absolute air pressure greater than atmospheric pressure, greater than the air pressure in spaces adjacent the clean room, or both. The positive air pressure in such rooms is provided by pumping filtered and/or conditioned air into the rooms and controlling the flow of air out of the rooms. The adjacent spaces, which may be manufacturing facilities or offices, are typically maintained at or close to atmospheric pressure by heating, ventilation, and air conditioning (HVAC) systems, or by providing an opening to the environment that allows the adjacent spaces to equilibrate with atmospheric pressure. Thus, air flowing from the positive pressure clean room will flow toward the lower pressure in adjacent rooms or to the atmosphere.

When a positive air pressure clean room is breached, air flowing to adjacent spaces or the atmosphere is generally not a problem as long as airborne contaminants present in the clean room do not pose a potential adverse health effect. Typically, the air inside clean rooms in which electronics, aerospace hardware, optical systems, military equipment, and defense-related research are manufactured or conducted may not contain airborne gases, vapors, and particulate matter at concentrations that present a safety or health concern to human health or the environment. However, that is not always the case, as other operations within those industries may generate contaminants that are above acceptable levels and, therefore, must be prevented from escaping the clean room without treatment.

A negative air pressure room is maintained at an absolute air pressure that is either less than atmospheric pressure, less than the air pressure in spaces adjacent the clean room, or both. The negative pressure is maintained by pumping air out of the room. Negative pressure rooms are often used when there is a concern that contaminants in the air may pose a potential health threat to human health in adjacent spaces, or the environment.

Notwithstanding the human health and environmental implications, certain types of manufacturing and research operations must be conducted within a positive air pressure clean room to satisfy regulatory requirements and industry-adopted good manufacturing and laboratory quality control standards. For example, state and federal regulations, including those promulgated by the National Institute for Occupational Safety and Health (NIOSH), may necessitate the use of positive or negative pressure clean rooms.

In particular, the U. Food & Drug Administration (FDA) requires that pharmaceutical production be done within the confines of clean rooms that provide for the validation and certification that manufactured batches of pharmaceutical products are being done in a sanitary environment.

Positive and negative air pressure clean rooms have been used for many years. <CIT>, for example, discloses a negative pressure apparatus and method for protecting the environment and populations from airborne asbestos and other particulate contamination inside a building, which includes an enclosure having a blower to pull air into a filtration unit inside the enclosure and dispel the filtered air to the atmosphere. <CIT> discloses the general features of a clean room.

Various FDA regulations and standards also specify requirements for air sampling and/or air monitoring equipment to be used inside clean rooms to verify or validate the cleanliness of the facility during certain drug manufacturing activities. The regulations also provide for electronic data recording, accuracy, precision, and record-keeping relating to monitoring the air quality within clean rooms. Similar requirements are imposed on other industries, such as the biotechnology industry.

<CIT> describes an air sampling device and method for collecting airborne pathogens and psychrometric data from a room or from remote air samples where the sample volume is electronically controlled by closely monitoring fan speed. The patent illustrates a device that draws room air into the device using a pump, which causes pathogen-containing particulates in the air to impact a growth/inhibitor media (a solid, liquid, gel, or mixture thereof) stored in a dish that is positioned within the sampling device. The patent states that previous sampling devices could not achieve a constant volumetric air flow of better than ± <NUM>% relative to a nominal or set-point flow rate, which caused a large variability in calculated concentrations of pathogens.

As the <CIT> patent suggests, one of the keys to successfully monitoring the air quality within a clean room is to ensure that the air flow rate through the air sampling/monitoring devices is very accurately determined during the time when a volume of air is collected. That fact is also appreciated in <CIT>, which discloses an electronically timed, positive displacement air sampling pump for use with a wide variety of air sample collecting devices and in a wide range of environmental conditions. The disclosed invention is said to provide for accurate average flow rate, independently metered total volume, operating time register, and audible "rate fault" alarm. In that patent, accuracy is achieved by using a timing circuit coupled with mechanical bellows.

<CIT> illustrates a control system flow chart for an air sampling device for use in a controlled environment. In particular, the patent discloses a controller logic that involves turning on a pump, checking pressure, monitoring sampling time, drawing air into the sampler, shutting off the pump, and checking for leaks in the lines. The patent also teaches using a purge system for purging the lines and associated air particulate sampler using a purge gas such as nitrogen gas.

<CIT> discloses a networked air measurement system.

<CIT> discloses an air monitoring system.

None of the prior art devices and air sampling methods described above are suitable for monitoring the level of contaminants in the air of a modern clean room, where issues of sample volume accuracy and precision, system control and monitoring, reporting, modularity, and remote monitoring are important. Accordingly, there exists a need for such a device and method for air sampling.

The air sampling/monitoring system of the present invention is useful in clean rooms such as those operated by pharmaceutical, biotechnology, semiconductor, and electronics industries, among others. The system is designed to test the air within a clean room to identify the level of viable contamination that is present in a volume of air. The system is set out in appended claims <NUM>-<NUM>.

It is an object of the present invention to provide a method for collecting a volume of air from a controlled environment within a facility. The method is set out in appended claims <NUM>-<NUM>.

Several preferred embodiments of the invention are described for illustrative purposes, it being understood that the invention may be embodied in other forms not specifically shown in the drawings.

Turning first to <FIG>, shown therein is a schematic of an exemplary facility <NUM> having one or more clean rooms <NUM> therein. The clean room <NUM> is adjacent a space <NUM> and the outdoor atmosphere <NUM>. The adjacent space <NUM> may be any one or more rooms within the same facility <NUM> that the clean room <NUM> is located and that adjoins the clean room <NUM>, such as, for example, a separate manufacturing room, another clean room, a finish and fill room, a research laboratory, or offices. The clean room <NUM> and adjacent space <NUM> are separated by a divider, such as a wall.

The clean room <NUM> in the exemplary facility <NUM> is capable of being maintained at an air pressure P<NUM> that is less than the air pressure P<NUM> of the adjacent space <NUM>, and also less than atmospheric air pressure PATM. This is accomplished by an HVAC system (not shown) that causes conditioned and filtered air to be pumped into the clean room <NUM> at a controlled flowrate Qin as depicted in <FIG>. Air inside the clean room <NUM> that is pumped out of or otherwise flows out of the clean room <NUM> is represented by Qout. As long as the difference between Qin and Qout is greater than zero, a positive pressure should be maintained in the clean room <NUM>.

Turning now to <FIG>, shown therein is a block diagram of an air sampling/monitoring system <NUM> according to one embodiment of the present invention for use in sampling or monitoring the air in the clean room <NUM>. The air sampling/monitoring system <NUM> includes a controller <NUM>, a vacuum pump <NUM>, an optional purge pump <NUM>, and an optional computer <NUM>, all of which may be co-located together in adjacent space <NUM> that is adjacent or remote from (i.e., not directly adjacent) the clean room <NUM>.

Remotely connected to the controller <NUM> is a stand-alone wall-mountable or benchtop touchpad <NUM> and one or more air sampling devices 216a, 216b, 216c,. , <NUM>n, where n is preferably <NUM>-<NUM>, but that number is not limited by the air sampling/monitoring system <NUM> to any particular quantity of air sampling devices. That is, the system is linearly scalable above or below <NUM> air sampling devices. A typical air sampling device suitable for use with the present invention is the SMA™ Atrium by Veltek Associates, Inc. , Malvern, PA. The air sampling devices 216a, 216b, 216c,. , <NUM>n according to the present invention may be any known air sampling device for collecting a volume of air. The terms "collecting," "sampling," "monitoring," and the like are not used to refer just to whole air sample devices, but also refer to devices that process a flow of fluid in order to separate certain gases, vapors, and particulate matter in the fluid for subsequent analysis and quantification. The terms "air" and "fluid" are used interchangeably to refer to gases, vapors, and particulates; thus, "air sampler" does not mean that only air is being collected.

Although <FIG> shows only a single touchpad <NUM> connected to multiple air sampling devices 216a, 216b, and 216c, it is also contemplated that there may be other arrangements of touchpads and air sampling devices. For example, there may be a one-to-one ratio of individual or discrete touchpads <NUM> and air sampling devices <NUM>, or perhaps a single touchpad <NUM> may be connected to two or more air sampling devices 216a and 216b, while a separate touchpad <NUM> may be connected to a third air sampling device 216c.

The touchpad <NUM> is in communication with the controller <NUM> using wireless means such as a receiver/transmitter <NUM> associated with the controller <NUM>, and a receiver/transmitter <NUM> associated with the touchpad <NUM>. The receiver/transmitters <NUM>, <NUM> are on the same high frequency that is unique to the overall air sampling/monitoring system <NUM>. The frequency is selected so as to reduce the likelihood of interference with other equipment in the facility <NUM>, and to permit communications when the controller <NUM> and the touchpad <NUM> are remotely located from each other.

The one or more air sampling devices 216a, 216b, 216c are connected to a vacuum pump <NUM> (described below) by way of the controller <NUM> using one or more air tubes <NUM>, which may be <NUM>-inch vacuum tubing on the clean room <NUM> side of the air sampling/monitoring system <NUM>, and <NUM>/<NUM>-inch vacuum tubing on the adjacent space <NUM> side of the air sampling/monitoring system <NUM>. Within the controller <NUM> is a manifold (not shown) that ties all of the individual air tubes <NUM> together and connects them to the vacuum side of the vacuum pump <NUM>. Individual solenoids (not shown) associated with the air tubes <NUM> are used to turn on the air flow to each air sampling device <NUM>.

The touchpad <NUM> and air sampling devices <NUM> are co-located together in the clean room <NUM>, or in a portion of the clean room <NUM>. The one or more air tubes <NUM> are connected to a wall-mounted quick disconnect outlet <NUM> located at the wall in the clean room <NUM>.

The vacuum pump <NUM> is a demand pump that operates upon receiving a signal from the controller <NUM> to operate at the beginning of an air sampling cycle. It is powered by a standard alternating current provided by the facility <NUM> in which the air sampling/monitoring system <NUM> is installed, or by power from the controller <NUM> (or both). The vacuum pump <NUM> is connected to the controller <NUM> using <NUM>-inch (inside diameter) vacuum tubing (other size tubing may also be used). The vacuum pump <NUM> according to one embodiment of the present invention is a <NUM> HP motor vacuum pump. The discharge from the vacuum pump <NUM> is directed outside the adjacent space <NUM>, or within the adjacent space <NUM>, as needed as shown by discharge tubes <NUM>.

The optional purge pump <NUM> may be connected to the controller <NUM> using <NUM>-inch (inside diameter) vacuum tubing (other size tubing may also be used). The discharge from the purge pump <NUM> is directed outside the adjacent space <NUM>, or within the adjacent space <NUM>, as needed. The discharge will most likely be processed through an abatement system (not shown) to collect or scrub purge gases and contaminants collected during the purge cycle (described below).

The computer <NUM> may be used as a data recorder. The computer <NUM> may be a dedicated computing device; however, if a dedicated or network computing device is already installed at the facility <NUM>, the computer <NUM> is not needed for data recording purposes. Data recorded by the computer <NUM> include time of sample, sample date, length of sample, and sample location, among other data.

Turning now to <FIG>, shown therein is a block diagram of the controller <NUM> of the present invention connected to a base station <NUM> and a touchpad <NUM>. The controller <NUM> includes one or more individual modular ports 308a, 308b, 308c,. , <NUM>n, for connecting the controller <NUM> to the individual air sampling devices 216a, 216b, 216c,. , <NUM>n, respectively, and one or more touchpads <NUM> (only one touchpad <NUM> is shown). The simplest configuration would be a single controller <NUM> having a single port 308a in one room, connected to one or more air sampling devices <NUM> and a single touchpad <NUM> in another room. An additional port 308b can then be added to the controller <NUM> to connect with an additional one or more air sampling devices <NUM> (and the touchpad <NUM> can be updated to have an interface that controls the second air sampling device <NUM> or a second touchpad <NUM> may be used). The touchpad <NUM> and air sampling devices <NUM> of the port 308b can be in the same room as the touchpad <NUM> and the air sampling devices <NUM> for the port 308a, but in a different area of that room, or can be in an entirely different room. The ports 308a, 308b, 308c,. , <NUM>n are further modular because they include their own dedicated power, hardware and software, including fittings and connectors necessary for operation. In other words, the modularity makes the system easily configurable by adding or removing ports 308a, 308b, 308c,. , <NUM>n to connect with individual touchpads <NUM> and their associates one or more air sampling devices 216a, 216b, 216c,. , <NUM>n, respectively.

Although <FIG> shows the touchpad <NUM> connected to a single port <NUM>n, it can be connected to each of the ports 308a, 308b, 308c,. , <NUM>n and, indirectly to each of the air sampling devices 216a, 216b, 216c,. , <NUM>n, respectively (or directly connected to each of the air sampling devices, as best shown in <FIG>). The controller <NUM> passes signals between the touchpad <NUM> and the sampling device <NUM> connected to a particular port <NUM>. Thus, the control signals send from the touchpad <NUM> or the port 308a are sent to the air sampling device <NUM> also connected to that same port 308a, but not to the air sampling device <NUM> connected to the port 308b.

Because the controller <NUM> is modular, it may have any number of ports n, depending upon the needs of the clean room <NUM> (or clean rooms) as specified, for example, in the individual facility air sampling protocol, standard operating procedures, quality assurance/quality control plans, regulations, etc. For example, the controller <NUM> may be used to control <NUM>, <NUM>, <NUM>,. n air samplers deployed within one or more clean rooms <NUM>, in which case it will have a corresponding number of ports. Preferably, one or more of the individual air sampling devices 216a, 216b, 216c,. , <NUM>n, and one touchpad <NUM> are connected to each one of the individual ports 308a, 308b, 308c,.

Each of the individual ports 308a, 308b, 308c,. , <NUM>n include at least a connector for connecting the individual ports 308a, 308b, 308c,. , <NUM>n to data loggers, such as the computer <NUM>, or to other devices. Preferably, at least two multi-pin connectors are used. Pairs of multi-pin connectors are electrically connected in parallel. A suitable pin connector would include, but is not limited to, a <NUM>-pin connector.

The base station <NUM> is needed in case the touchpad <NUM> is designed without wireless communications features for communicating with the controller <NUM>. The base station <NUM> may be co-located with the touchpad <NUM> inside the clean room <NUM>. The base station <NUM>, which acts primarily as a data communications relay between the touchpad <NUM> and the controller <NUM>, may be operatively connected to the touchpad <NUM> via a data communications network <NUM> such that the touchpad <NUM> does not need to be directly connected to the controller <NUM> (i.e., it may be connected wirelessly). The data communications network <NUM> may be any proprietary or public network, including a packet-switched network, such as the Internet, a local area network, a wireless network, or a combination of networks. Communications between the base station <NUM> and the touchpad <NUM> via the data communications network <NUM> could be facilitated by receiver/transmitters <NUM>, <NUM>.

The controller <NUM> and the base station <NUM> may be operatively connected to each other via a wireless data communications network <NUM> using an integrated radio with digital input/outputs (not shown). The data communications network <NUM> may be any proprietary or public network, including a packet-switched network, such as the Internet. The receiver/transmitters of the controller <NUM> and the base station <NUM> are on the same high frequency that is unique to the overall air sampling/monitoring system <NUM>. The frequency is selected so as to reduce the likelihood of interference.

The base station <NUM> interface operates as a two-way (point to point) monitoring and control device with expandable input/output options. The receiver/transmitter <NUM> located in the base station <NUM>, and the receiver/transmitter <NUM> located in the touchpad <NUM> located in the clean room <NUM> are a dedicated pair that only communicate with each other. The receiver/transmitters <NUM>, <NUM> connect to input/output circuit boards that observe that the individual ports 308a, 308b, 308c,. , 308n are powered up, are in an air sampling mode, and broadcast an air flow error during an air sampling cycle. The base station <NUM> can detect the state of activity of each of the individual ports 308a, 308b, 308c,. The base station <NUM> located near the controller <NUM> has an input/output that is cabled directly to its corresponding port 308a, 308b, 308c,. , <NUM>n in the controller <NUM>.

Turning now to <FIG>, shown therein is a block diagram of an exemplary port <NUM> of the controller <NUM> according to one embodiment of the present invention. The port <NUM> has its own dedicated timer <NUM>, air flow switch <NUM>, direct current power supply <NUM>, air tube interface <NUM>, facility System Control and Data Acquisition (SCADA) interface <NUM>, and computer <NUM>. The port <NUM> is modular and independent of other ports associated with the controller <NUM>, as previously described. Thus, in the event the port <NUM> fails, the remaining ports associated with the controller <NUM> can continue to function within calibration tolerances. The modular design also removes the possibility of a single point system failure. The port <NUM> has its own direct current power <NUM>, and is not dependent on a centralized power source to operate. Ground loop or direct current voltage shifts are eliminated by using optical coupling circuits (not shown), thus providing stable and robust performance. These circuits isolate the SCADA direct current ground and the SCADA voltage distribution system from the direct current voltage and ground distribution system (not shown) of the controller <NUM>. If a facility system is present, it and the controller <NUM> will not depend on a common direct current ground bus connection. This enables the facility system and the controller <NUM> to be connected with long cables without extraordinary direct current ground interconnection between the two systems. The facility system sends a current signal or receives a current signal that is referenced to the facilities' direct current power system. This is a safe and effective way of eliminating the interconnection of two systems that have different power requirements.

The dedicated timer <NUM> is used to monitor the air sampling cycle duration. The timer <NUM> may be located at the controller <NUM> outside the clean room <NUM>, or at the touchpad <NUM> inside the clean room <NUM> and connected to the controller <NUM> via line <NUM>. The status of the timer <NUM> for the port <NUM> is observable at the controller <NUM> and/or at the touchpad <NUM>. Each timer <NUM> may run independently or simultaneously with other ports <NUM>. The timer <NUM> may be calibrated to a known standard to obtain very accurate readings. The timer <NUM> starts the air sampling cycle and issues commands through its input/output to open solenoids (not shown) and start the vacuum pump <NUM>. The timer <NUM> lets the air flow switch <NUM> know that a sampling cycle has been initiated and declares a <NUM> cfm error signal if the proper air flow is not present. The timer <NUM> also provides +<NUM> volts direct current power to other components of the port <NUM> and touchpad <NUM>.

The controller <NUM> has an internal interface that can connect to a customer's SCADA interface <NUM>, or computer <NUM>, or a programmable logic controller (PLC) that can interface with a monitoring system associated with the facility <NUM>. The controller <NUM> includes an isolator interface (not shown) that will not create any voltage shifts or ground loops when connected to a facility system, which can cause information problems for the facility or the controller <NUM>. The purge mode of the controller <NUM> is not interfered with or affected by the wireless controls or isolation interface input/outputs of the system <NUM>.

The nominal or set-point volumetric flow rate through each of the one or more air sampling devices 216a, 216b, 216c is <NUM> cfm (or <NUM> lpm). This is accomplished by the <NUM> cfm circuit and the air flow switch <NUM>. The air flow switch <NUM> includes a digital air flow display <NUM> that may be programmed to display air flow rate in liters per minute (lpm), cubic feet per minute (cfm), or other units. The air flow switch <NUM> generates an error signal if the air flowing through the port <NUM> during an air sampling cycle, T, does not meet a pre-programmed or set-point <NUM> cfm air flow value or satisfy pre-determined tolerances. The signal allows the user to be alerted to a problem with a particular air sample. Because the air flow switch <NUM> is a digital switch, it may be easily calibrated against a standard flow switch (such as a National Institute of Standards and Technology-certified switch), and it is insulated from affects caused by pressure variations in the air flow tubing or the location of the air flow switch <NUM>. A digital flow switch also eliminates internal piping variations from system to system, and it has an integrated flow adjustment pinch valve, which reduces piping.

The air flow switch <NUM> is mechanically and electrically connected to an air tube interface <NUM>, which receives air tube <NUM> to provide a physical connection between the air flow switch <NUM> of the port <NUM> and a remote air sampling device <NUM> (as shown in <FIG>). While a digital air flow switch <NUM> is preferred, a float type meter (rotameter) could also be used, if pressure variations are taken into account. Rotameters are less desirable because, among other things, it may be necessary to provide a calibration conversion device and computed transfer function, and the rotameter must be positioned at a suitable level and angle to permit accurate manual readings.

The air flow switch <NUM> sits between the one or more air sampling devices 216a, 216b, 216c and the <NUM> cfm circuit, and is designed to maintain a steady-state flow rate through the one or more air sampling devices 216a, 216b, 216c and associated air tubing <NUM>, with a detectable air flow rate deviation tolerance of ± <NUM>-percent from the nominal set-point flow rate (typically, the concern is when the flow rate decreases <NUM>% from the nominal set-point flow rate). This air flow rate accuracy, which provides a margin of error of about <NUM>-percent for a system calibrated for ±<NUM>-percent, for example, is achieved through a combination of routine and non-routine calibration checks using a standard flow switch, as discussed above, and software and hardware that constantly monitors flow rate in real-time or near real-time. The air flow switch <NUM> is programmed to send an error signal to a <NUM> cfm circuit board (not shown) when the air flow is below the programmed set-point or low-flow value. That is, the flow switch <NUM> informs the <NUM> cfm circuit that the air flow is below the <NUM>-percent minimum level programmed into the system. The <NUM> cfm circuit checks to ensure the air flow rate error is valid. If the circuit confirms the validity of the air flow, it sends a signal to the individual port 308a, 308b, 308c,. , <NUM>n that is doing the air sampling.

The flow switch <NUM> has low and high set-points, which are programmable. When the air flow is too far above or below the set-point values, the flow switch <NUM> sends a digital "on" signal to the <NUM> cfm circuit that the air flow is in error. The <NUM> cfm circuit is active during an air sampling cycle, and a signal from the flow switch <NUM> will cause the <NUM> cfm circuit to send or broadcast a flow error to the controller <NUM>, touchpad <NUM>, wireless control panels, and an isolator controller <NUM> (<FIG>).

The SCADA interface <NUM> allows the port <NUM> to connect to a facility SCADA, which allows the air sampling/monitoring system <NUM> to be integrated into other facility data collection and monitoring systems. The isolation interface prevents the present system from compromising the controller or the SCADA system performance by eliminating ground loops and voltage shifts when connecting to third-party equipment, as previously described.

The port <NUM> may be directly connected to, or interconnected to, a separate computer <NUM> in addition to being connected to the touchpad <NUM>. The separate computer <NUM> has software and hardware to implement the functions of the port <NUM>. The separate computer <NUM> can be a processor with memory. The controller <NUM> may also have a central processor, and the separate computer <NUM> communicates with that processor to control the overall operation of the controller <NUM> and the air sampling/monitoring system <NUM>.

Turning now to <FIG>, shown therein is a purge system <NUM> for purging the air sampling devices 216a, 216b, 216c,. , <NUM>n and associated air tubes <NUM> to ensure there is no residual contaminants in those portions of the air sampling/monitoring system <NUM>. An isolator controller <NUM> controls operation of the vacuum pump <NUM> and purge pump <NUM> in accordance with an air sampling cycle and a purge cycle. In the air sampling cycle, the isolator controller <NUM>, which can be a three-way solenoid, causes the vacuum pump <NUM> to stop by sending a signal to the vacuum pump <NUM> via an electrical connection <NUM>. At the same time, the isolator controller <NUM> controls the purge pump <NUM> to engage by sending a signal to the purge pump <NUM> via an electrical connection <NUM>. When those signals are sent, air is not pulled through the air sampling devices 216a, 216b, 216c,. , <NUM>n and air tube <NUM> by the vacuum pump <NUM>, but is instead pulled through the air sampling devices 216a, 216b, 216c,. , <NUM>n and air tube <NUM> by the purge pump <NUM>. Thus, during the air sampling cycle, air flow is steered to the vacuum pump <NUM> and the purge path is closed. The opposite is done during the purge cycle, whereby air flow is steered to the purge pump <NUM> and the air sampling path is closed.

Although the isolator controller <NUM> preferably is associated with up to <NUM> individual ports <NUM> and corresponding air sampling devices <NUM>, <FIG> shows only one port/air sampling device. During any air sampling cycle, the controller <NUM> is prevented from initiating a purge cycle. However, once the air sampling cycles for each of the air sampling devices <NUM> are complete, the controller <NUM> is set in the purge mode. The isolator controller <NUM> ports each have a dedicated solenoid (not shown) that will direct the air collected during the purge cycle to a purge exit <NUM> (as best seen in <FIG>).

<FIG> is a process flow diagram illustrating the isolator controller logic according to one embodiment of the present invention. In step <NUM>, the process enables the air sampling cycle, which is the normal operation of the system. In step <NUM>, the isolator controller <NUM> checks if the vacuum pump <NUM> is on. If the vacuum pump <NUM> is on, then the purge pump <NUM> is necessarily off, since the isolator controller <NUM> can only enable the vacuum pump <NUM> or the purge pump <NUM> at any one time. If the vacuum pump <NUM> is not on, then the vacuum pump <NUM> is turned on in step <NUM>. This can be accomplished automatically based on a preprogrammed time or operation, or manually by entering a command at a remote computer <NUM> or at the local touchpad <NUM>.

In step <NUM>, the isolator controller <NUM> keeps the vacuum pump <NUM> on. In step <NUM>, the isolator controller <NUM> checks to see if the purge cycle should continue to be disabled. If so, the process returns to step <NUM> and the sampling cycle continues. Once the isolator controller <NUM> receives a signal from the controller <NUM> to enter the purge cycle, in step <NUM>, the isolator controller <NUM> starts the purge cycle. At the end of the purge cycle, the isolator controller <NUM> returns to the air sampling cycle, at step <NUM>, or possibly shuts off the system until the next air sampling system starts. In general, the purge cycle will run until the next air sampling cycle is scheduled, which could be, for example, once every <NUM> hours. In some clean rooms <NUM>, such as a class <NUM> clean room, it may not be necessary to run a purge cycle during the period when the air sampling cycle is not being performed. The isolator controller logic is implemented by an isolator printed circuit board (not shown) that interfaces with the SCADA (typically operated by a PC) or programmable logic controllers. The board eliminates the joining of the facility voltage system with the power system of the present invention.

The isolation circuit board is located in the controller <NUM> and can be connected to the SCADA or to a programmable logic controller system. All commands and observations can be made at the touchpad <NUM>. The wireless and isolation features of the system <NUM> can be implemented on any of the three interfaces connected to the controller <NUM>. For example, when a wireless panel receives a command to start an air sampling cycle, the touchpad <NUM>, the controller <NUM>, and the computer <NUM> will each observe the air sampling cycle in progress. Also for example, when a air flow error is detected, the controller <NUM> can broadcast the error detected in a particular port <NUM> to the touchpad <NUM> and the computer <NUM> (or any other input/output device connected to the system <NUM> that may be used).

The purging cycle involves injecting steam, hydrogen peroxide, or other vapor/gas into the air flow through the air sampling devices 216a, 216b, 216c,. , <NUM>n and air tube <NUM>. This may be accomplished by isolating the air sampling devices 216a, 216b, 216c,. , <NUM>n in one or more isolator chambers <NUM> and introducing a flow of purging gases at flow rate Qg into the chamber when the purge cycle is turned on. The isolator chamber <NUM> does not have or allow any human contact inside the enclosure. Other techniques for purging and decontaminating air tubes are well known in the art. Users of the present system involved in pharmaceutical manufacturing operations will desire to sanitize various system components before any drug substances are mixed and before commencing with finish and fill operations. The purge mode of the present invention allows the sterilization of the tubes directly connected to the isolator. The purge vapor/gas exits the isolator controller <NUM>. During the isolated purging cycle, the air flowing through the air tube <NUM> may be conditioned by gas conditioning device <NUM>, which may comprise particulate filters (not shown), organic adsorbents, activated charcoal, a knockout drum, cyclone, or other substance or device, or combination of substances and devices.

Turning now to <FIG>, shown therein is a block diagram of a touchpad <NUM> according to one aspect of the present invention. The touchpad <NUM>, as discussed previously, may be a static wall-mounted device, or it may be portable and adapted to being located on any flat surface, such as a bench, inside a working area of the clean room <NUM>. The touchpad <NUM> is the human interface input/output device for the air sampling/monitoring system <NUM>. It remotely controls the controller <NUM> which is located outside the clean room <NUM>. This design removes most of the electronics of the system from the aseptic areas of the clean room <NUM>, including the system power supply, flow switch circuitry, and other electronics. The touchpad <NUM> electronics are sealed inside the device so that the device may be disinfected like other portions of the clean room <NUM>.

The touchpad <NUM> allows the user to start, stop, program, and monitor the air sampling and purge cycles within the clean room <NUM>. It also allows the user to abort an air sampling cycle, hear an audible signal or observe a visible signal when an air sampling cycle is complete, observe an airflow error if one is detected during an air sampling cycle, and activate an alarm. For example, a visible signal may be generated when the system detects a <NUM> cfm air flow error above or below a pre-programmed set-point flow rate. The visible signal may cause one or more light-emitting diodes (LEDs) to illuminate to provide a visible alarm to the user. A start up/abort printed circuit board (not shown) controls the run and abort inputs of the timer <NUM> (see <FIG>).

The start signal is an input to the controller <NUM> from the touchpad <NUM> or the timer <NUM> (associated with one of the ports <NUM>), which will initiate a sampling cycle in the controller <NUM> hardware. When the individual ports 308a, 308b, 308c,. , <NUM>n on the controller <NUM> receive the start signal, the controller <NUM> will start a sampling cycle by controlling isolator controller <NUM>. The controller <NUM> then informs the touchpad <NUM> that a sampling cycle instruction signal has been issued.

The abort signal is an input to the controller <NUM> that halts the sampling cycle already in progress. When the individual ports 308a, 308b, 308c,. , <NUM>n of the controller <NUM> receive the abort signal, the controller <NUM> will instruct the touchpad <NUM> by controlling isolator controller <NUM>. The controller <NUM> then informs the touchpad <NUM> that the sampling cycle instruction signal has been halted.

When a sampling cycle is in progress, the individual ports 308a, 308b, 308c,. , <NUM>n of the controller <NUM> will instruct the touchpad <NUM> and, if necessary, the SCADA interface <NUM> (in order to communicate with a separate facility system), that a sampling cycle is in progress and this signal will remain active for the remainder of the sampling duration.

When an individual port 308a, 308b, 308c,. , <NUM>n is in the middle of a sampling cycle and an air flow deficiency is detected, the controller <NUM> will broadcast a <NUM> cfm error to the port that is sampling. The power input to the SCADA system will go from active to non-active during a sampling cycle for that port, and continue on/off for the duration of the sampling cycle or until the <NUM> cfm error is removed.

The touchpad <NUM> includes a display <NUM>. The display <NUM> includes switches for powering up the touchpad <NUM> and the individual ports 308a, 308b, 308c,. , <NUM>n on the controller <NUM> to which the touchpad <NUM> is connected One or more LEDs provides a visual confirmation that the power on the touchpad <NUM> has been activated and that the vacuum pump <NUM> is on. The display <NUM> is adapted to display accurate flow rate information regardless of the composition of the air (i.e., amount of nitrogen, argon, and carbon dioxide gases).

Each touchpad <NUM> includes its own power source <NUM>, or it may be electrically connected and powered by the controller <NUM> through cable <NUM> (which is the same as cable <NUM> in <FIG>), which provides voltage to the touchpad <NUM>. The touchpad <NUM> utilizes a shielded plenum wire consisting of less than about <NUM> watts of power.

The touchpad <NUM> wirelessly provides a signal to one of the individual ports 308a, 308b, 308c,. , 308n on the controller <NUM>. The touchpad <NUM> may also provide a signal to one of the other individual ports 308a, 308b, 308c,. , 308n on the controller <NUM>.

Turning now to <FIG>, shown therein is a block diagram of an air sampling/monitoring system <NUM> according to another embodiment of the present invention for use in the clean room <NUM>. The air sampling/monitoring system <NUM> includes an air sampling device <NUM>, a controller <NUM>, a base module <NUM>, and a control panel <NUM>.

The air sampling device <NUM> in <FIG> is shown located within a laminar air flow hood or isolation chamber <NUM>, which may include a high efficiency particulate air (HEPA) filter (not shown). The the air sampling device <NUM> and the controller <NUM> are provided in a single portable device that may be placed in any location within the clean room <NUM>, or outside the clean room <NUM>, as necessary.

The controller <NUM> may include a self-contained air sampling pump <NUM>. The air sampling device <NUM> is attached to the controller <NUM> as shown using a vacuum air tube that is about seven feet or less. The features of the controller <NUM> are similar to those described above in connection with the description of <FIG>. For example, the controller <NUM> provides for a <NUM> cfm air flow error detection during an air sampling cycle, and it is easily connected to a facilities' SCADA.

The base module <NUM> is electrically connected to the controller <NUM> and air sampling device <NUM>, or wirelessly connected to the controller <NUM> via network <NUM> using receiver/transmitter <NUM>. The base module <NUM>, which is typically fixed at a location near the air sampling device <NUM>, routes signals between the controller <NUM> and the control panel <NUM> either by wire or wireless network <NUM> using receiver/transmitter <NUM>. Thus, the panel <NUM>, which may be wall-mountable, provides the user with input/output control of the air sampling device <NUM> by way of the controller <NUM>. Because the configuration in <FIG> is wireless, the air sampling/monitoring system <NUM> does not require any penetration of walls, ceilings, or floors for routing of cables or air tubes.

Claim 1:
A method for collecting a volume of air from a controlled environment (<NUM>) within a facility (<NUM>), comprising the steps of:
providing two or more air sampling devices (216a, 216b, 216c, ... 216n) at different locations within the controlled environment (<NUM>);
providing a controller (<NUM>) at a location (<NUM>) outside the controlled environment (<NUM>) that includes a port (308a, 308b, 308c, ... <NUM> n) corresponding to each of the two or more air sampling devices (216a, 216b, 216c, ...216n), each port (308a, 308b, 308c, ... <NUM> n) having its own dedicated flow switch (<NUM>) and tube port (<NUM>) in separate fluid communication with its corresponding air sampling device (216a, 216b, 216c, ... 216n) via a corresponding air tube (<NUM>), each flow switch (<NUM>) being configured to separately monitor fluid flow through its corresponding air sampling device (216a, 216b, 216c, ... 216n), and each port (308a, 308b, 308c, ... 308n) includes a dedicated timer (<NUM>) for monitoring air sampling duration; and
providing a vacuum source (<NUM>) at a location (<NUM>) outside the controlled environment (<NUM>) that is in fluid communication with each tube port (<NUM>) in the controller (<NUM>) via a manifold, wherein the vacuum source (<NUM>), manifold, ports (308a, 308b, 308c, ... <NUM> n), and air tubes (<NUM>) are configured to simultaneously draw fluid from two or more of the two or more air sampling devices (216a, 216b, 216c, ... 216n);
characterized in that the method further comprises:
providing a touchpad (<NUM>), within the controlled environment (<NUM>), that is wirelessly connected to the controller (<NUM>) and includes a communication device (<NUM>) configured to send start and stop signals to the controller (<NUM>) to separately turn air flow on and off at different air sampling devices (216a, 216b, 216c, ..., 216n) with their corresponding flow switches (<NUM>) when collecting the volume of air;
communicating start and stop signals from the at least one touchpad (<NUM>) to the controller (<NUM>) to separately turn air flow on and off at different air sampling devices (216a, 216b, 216c, ..., 216n) with their corresponding flow switches (<NUM>) to draw a first predetermined volume of fluid through each of the different air sampling devices (216a, 216b, 216c, ..., 216n); and
starting air sampling cycles, by each of timer (<NUM>) of each port (308a, 308b, 308c, ... 308n), by issuing commands to open solenoids and start the vacuum pump (<NUM>).