Tracer detection system and method for characterizing the effectiveness of air removal within an aerosol zone

Abstract

One variation of the method includes, during a tracer test, triggering the release of a tracer load into air in the aerosol zone by a dispenser temporarily positioned within the aerosol zone, the tracer load including a concentration of aerosol tracer, and recording a time series of aerosol data via a sensor unit temporarily positioned within the aerosol zone, the time series of aerosol data representing a concentration of aerosol particles present in the air. The method further includes deriving a tracer concentration curve representing changes in the concentration of aerosol tracer particles based on the time series of aerosol data and the concentrations, deriving an airflow value representing removal of aerosol particles from the aerosol zone during the tracer test based on characteristics of the tracer concentration curve, and interpreting an outcome of the tracer test based on a difference between the airflow value and a target airflow value defined for the aerosol zone.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application No. 18 / 077,185, filed December 7, 2022, and U.S. Provisional Application No. 63 / 405,340, filed September 9, 2022, each of which is incorporated by reference in its entirety.

[0002] The present invention relates generally to the field of metagenomics, and more particularly to a new and useful system and method for characterizing air removal effectiveness within an aerosol zone in the field of metagenomics. [Brief explanation of the drawings]

[0003] [Figure 1] FIG. 1 is a flow chart representation of the method. [Figure 2] 2A and 2B are flow chart representations of the method. [Figure 3] 3A, 3B, and 3C are flow chart representations of the method. [Figure 4] FIG. 4 is a flow chart representation of the method. [Figure 5] 5A and 5B are schematic diagrams of the system. DETAILED DESCRIPTION OF THE INVENTION

[0004] The following description of embodiments of the invention is not intended to limit the invention to these embodiments, but rather to enable those skilled in the art to make and use the invention. The variations, configurations, implementations, example implementations, and examples described herein are optional and are not limited to only the variations, configurations, implementations, example implementations, and examples described. The invention described herein can include any and all permutations of these variations, configurations, implementations, example implementations, and examples.

[0005] 1. Method: Aerosol tracer particles As shown in Figures 1, 2A, 2B, 3A, 3B, 3C, and 4, method S100 includes, during a first test period in an aerosol zone, recording, in block S110, a first time series of aerosol data via a set of sensors 122 integrated into a first sensor unit 120 temporarily positioned at a first unit location within the aerosol zone, wherein the first time series of aerosol data represents a concentration of aerosol particles present in the air at the first unit location during the first test period; and, during a first dispense period in block S120, triggering the release of a first tracer load into the air in the aerosol zone by a dispenser 110 temporarily positioned at a dispenser 110 location within the aerosol zone—offset from the first unit location by a target distance—wherein the first tracer load includes a test concentration of aerosol tracer particles. The method S100 further includes, in block S130, deriving a first tracer concentration curve representing a change in concentration of aerosol tracer particles at the first unit location during a first test period based on the first time series of aerosol data and the test concentration; in block S140, deriving a first airflow value representing the removal of aerosol particles from the aerosol zone during the first test period based on characteristics of the first tracer concentration curve; and interpreting a first outcome of the first tracer test based on a difference between the first airflow value and a target airflow value defined for the aerosol zone.

[0006] In one variation, method S100 further includes validating a first set of removal paths (e.g., particle capture, particle deposition, ventilation) employed within the aerosol zone during the first test period in response to the first outcome corresponding to a target outcome (e.g., a "pass" outcome, at least a threshold score). Additionally or alternatively, in another variation, method S100 further includes withholding validation of the first set of removal paths employed within the aerosol zone in response to the first outcome being different from the target outcome.

[0007] 1.1 Method: Aerosol tracer particles + tracer gas 2A-2B, 3A-3C, and 4, one variation of method S100 includes, during a first distribution period during which a first tracer test is performed within the aerosol zone within a first test period, discharging a first tracer load into the air within the aerosol zone via a dispenser 110 temporarily positioned at a target location within the aerosol zone, the first tracer load including a first concentration of aerosol tracer particles and a second concentration of tracer gas; recording a first time series of aerosol data via a first sensor temporarily positioned at the first location within the aerosol zone, the first time series of aerosol data representing the presence of aerosol particles in the air at the first sensor during the test period; and recording a second time series of gas data via a second sensor temporarily positioned at a second location within the aerosol zone, the second time series of gas data representing the presence of the tracer gas in the air at the second sensor during the test period. In this variation, method S100 further includes deriving an aerosol tracer concentration curve representing the time series concentration of aerosol tracer particles in the aerosol zone during the test period based on the first time series of aerosol data and the first concentration, characterizing a first airflow value representing the removal of airborne particles from the aerosol zone based on characteristics of the aerosol concentration curve, interpreting a gas tracer concentration curve representing the time series concentration of tracer gas in the aerosol zone during the test period based on the second time series of gas data and the second concentration, and deriving a second airflow value representing the removal of gas from the aerosol zone based on characteristics of the gas concentration curve.

[0008] 2. Tracer detection system: particle sensor + gas sensor As shown in Figures 4, 5A, and 5B, the tracer detection system 100 includes a dispenser 110 that is temporarily installed at a dispenser 110 location within the aerosol zone and includes a reservoir 112 containing a mixture of a non-volatile tracer and a volatile tracer in solution, an actuator 116 configured to release a tracer test load from the reservoir 112 and into the aerosol zone, the tracer test load including a first concentration of aerosol tracer and a second concentration of tracer gas, and a first power module 118 configured to supply power to the actuator 116.

[0009] The tracer detection system 100 further includes a first sensor unit 120 disposed at a first unit location within the aerosol zone—offset from the dispenser 110 location by a target distance—and including a first set of sensors 122, a sensor communication module 124, a controller 124, and a second power module 128 configured to temporarily provide power to the first set of sensors 122, the controller 124, and the sensor communication module 124. The first set of sensors 122 includes a first particle sensor configured to signal the presence of aerosol particles in the air at the first unit location and a first gas sensor configured to signal the presence of tracer gas in the air at the first unit location. The controller 124 is configured to read a first time series of signals from the first particle sensor in response to a command received by the sensor communication module 124, read a second time series of signals from the gas sensor in response to the command, interpret a time series amount of aerosol particles in the air flowing through the first unit location based on the first time series of signals, and interpret a time series amount of tracer gas in the air flowing through the first unit location based on the second time series of signals.

[0010] In one variant, the tracer detection system 100 further includes a computer module 130 (e.g., a computer system) configured to transmit commands to the sensor communication module 124 to selectively trigger the recording of time-series tracer data via a set of sensors 122 integrated within the sensor unit 120, and to convert the time-series tracer data recorded by the controller 124 into a set of airflow values ​​representing the airflow within the aerosol zone during the execution of the tracer test.

[0011] In one variation, the tracer detection system 100 further includes a second sensor unit 120 disposed at a second unit location within the aerosol zone and including a second set of sensors 122 including a second particle sensor configured to signal the presence of aerosol particles in the air at the second unit location and a second gas sensor configured to signal the presence of tracer gas in the air at the second unit location, a second sensor communication module 124, a second controller 124, and a third power module 128 configured to supply power to the second controller 124 and the second set of sensors 122. The second controller 124 is configured to: read a third time series of signals from the second particle sensor in response to a command received by the second sensor communication module 124; read a fourth time series of signals from the second gas sensor in response to a command received by the second sensor communication module 124; interpret the time series of amounts of aerosol particles in the air flowing through the second unit location based on the third time series of signals; and interpret the time series of amounts of tracer gas in the air flowing through the second unit location based on the fourth time series of signals. In this variation, the first sensor unit 120 and the second sensor unit 120 cooperate to define a target placement of the sensor unit 120 located near the dispenser 110.

[0012] 3. Application In general, the blocks of method S100 can be performed by a computer system (e.g., a local or remote computer system, computer network, local or remote server) in conjunction with a tracer detection system 100 (hereinafter "system") - including a dispenser 110 and sensor units 120 - to dispense a known concentration of a tracer (e.g., aerosolized tracer particles, volatile tracer) in solution into a defined indoor environment (or "aerosol zone") via a dispenser 110 temporarily installed at a dispenser 110 location within the indoor environment, simultaneously capture time-series tracer data - representing the concentration of the tracer in the air - via a set of sensor units 120 temporarily positioned near the dispenser 110 in a target configuration, and derive time-series concentrations of these tracers - represented by tracer concentration curves - in the indoor environment over time following the dispersion of the tracer into the indoor environment by the dispenser 110. The computer system can then utilize this tracer concentration curve to derive insights into the flow and / or removal of air - including gases and / or particles - in this particular environment.

[0013] In one implementation, the tracer detection system 100 can be configured to be temporarily deployed in a particular facility—such as an office building, a residence, a restaurant, a classroom, a shopping mall, a hospital, an airport terminal, etc.—and to spray a known amount of tracer (e.g., salt particles) into the facility via the release of a tracer test load in the molecular tracer sprayer 110 and detect the amount of aerosol particles—including the aerosolized tracer—in the ambient air within the facility in the sensor unit 120. In this implementation, the sprayer 110 can be configured to perform the tracer release according to a particular set of release parameters—including a particular release time (e.g., timestamp, time period), total duration of the tracer release, a target frequency per release of the tracer during the tracer release, the amount of tracer (e.g., salt) released per release, etc.—to generate a detectable tracer signal configured to link the tracer detected by the sensor unit 120 to the tracer sprayed during the particular tracer release. The sensor unit 120—including a set of sensors 122 (e.g., aerosol particle counter, gas sensors) configured to detect the presence of aerosols in the air—can then be configured to record a time series of aerosol data representing the time-stamped quantity of aerosol particles (e.g., aerosolized tracer) detected in the air at the sensor unit 120 following the execution of a tracer release. The system can then utilize the time series of aerosol data in combination with the known release parameters to interpret a tracer signal (e.g., a curve or model) representing the change in the quantity of tracer of the tracer type detected at the sensor unit 120 over time following the distribution of the tracer test load. Based on the characteristics of this tracer signal, the system can then derive a set of airflow values—such as an air exchange rate (e.g., volumetric air exchange rate) and / or exposure reduction rate—representing the flow of aerosols within this particular space.

[0014] In particular, during the test period, the system can perform tracer tests to derive insights into aerosol behavior—related to flow, movement, and / or dispersion patterns, etc.—within specific aerosol zones within the facility. In preparation for performing tracer tests, the aerosol detection system 100 can be deployed to the facility for installation within specific aerosol zones and / or throughout groups of aerosol zones within the facility. In one implementation, the aerosol detection system 100—including, for example, one dispenser 110 and one or more air samplers—can be temporarily deployed and installed within the aerosol zone for a defined duration (e.g., 10 minutes, 30 minutes, 1 hour, 24 hours) to enable the execution of a tracer or series of tracer tests during this duration. Once installed within the aerosol zone, the system can perform tracer tests accordingly and interpret a set of airflow values ​​for the aerosol zone based on the time-series aerosol data recorded during the execution of the tracer tests. The aerosol detection system 100 can then be removed from the aerosol zone upon completion of the tracer test or series of tracer tests - such as for installation in another aerosol zone within the facility and / or storage elsewhere.

[0015] For example, an operator associated with the aerosol zone can place a dispenser 110 and an air sampler 120 within the aerosol zone (e.g., in a target configuration) in preparation for conducting tracer tests. Once deployed within the aerosol zone, the system can initiate a test period of a target duration (e.g., 10 minutes, 30 minutes, 1 hour, 24 hours), perform one or more tracer tests within the test period—including the release of a tracer test load by the dispenser 110 and the recording of time-series aerosol data by the air sampler—output results for each tracer test in (near) real time—such as aerosol metrics (e.g., air exchange range, aerosol reduction rate, air velocity and / or direction), risk levels associated with one or more pathogens, and effectiveness of various interventions or environmental controls (e.g., HVAC settings, occupancy levels, activity levels), and report these aerosol metrics and / or additional insights in (near) real time to a manager associated with the aerosol zone. The system can therefore derive deep insights into the flow and movement of aerosols within the aerosol zone through the execution of (relatively) simple tracer tests (e.g., 10-minute tests, 20-minute tests, 1-hour tests).

[0016] For example, as shown in Figures 3A-3C, the system can derive a tracer concentration curve based on time-series aerosol data captured by one or more sensor units 120 deployed in the aerosol zone during a tracer test, representing the decay of the concentration of the tracer in the air in the aerosol zone over a decay period following application of a tracer test load to the aerosol zone, and extract characteristics from this concentration curve, including the area under the curve (or "AUC"), maximum concentration of the tracer, final concentration of the tracer, baseline concentration of the tracer in the aerosol zone, decay rate (e.g., slope of the curve), etc., to derive an airflow value (e.g., volumetric airflow rate) representing the removal of tracer particles from the aerosol zone during the tracer test. Additionally, the system may compare this airflow value with a target airflow value—such as a target removal rate and / or a target air exchange rate (e.g., a target volumetric airflow rate)—defined for the aerosol zone, and interpret an outcome—such as a “pass” or “fail” outcome—of the tracer test based on the difference between the target airflow value and the (measured) airflow value. Based on the outcome, the system may selectively suggest implementation and / or modification of various removal pathways—related to capture, filtration, precipitation, ventilation, etc.—employed within the aerosol zone.

[0017] Additionally, in one variation, the system can utilize the differential distribution and detection of different types of tracers to derive insight into the different types of air removal methods employed within the aerosol zone. In particular, the system can dispense a tracer test load containing known concentrations of an aerosol tracer (e.g., salt) and a tracer gas (e.g., IPA) via a dispenser 110; record time-series aerosol data—representing the concentration of the aerosol over time—via a set of aerosol sensors 122 integrated into one or more sensor units 120 positioned near the dispenser 110 in a target configuration; record time-series gas data—representing the concentration of the tracer gas over time—via a set of gas sensors 122 integrated into one or more sensor units 120 positioned near the dispenser 110; interpret an aerosol concentration curve based on the time series of aerosol data—and thus derive an aerosol airflow value representative of airborne particle removal from the aerosol zone (e.g., based on characteristics of the aerosol concentration curve); and interpret a gas concentration curve based on the time series of gas data—and thus derive a gas airflow value representative of gas removal from the aerosol zone (e.g., based on characteristics of the gas concentration curve).

[0018] The system can thus utilize the aerosol airflow value (e.g., the first volumetric airflow) to derive insights regarding particle removal pathways (e.g., ventilation, precipitation, capture) associated with particle and / or aerosol removal within the aerosol zone, and can utilize the gas airflow value (e.g., the second volumetric airflow) to derive insights regarding gas removal pathways (e.g., ventilation, precipitation, capture) associated with gas removal from the aerosol zone. The system can thus validate gas removal pathways—such as those related to ventilation and / or outdoor air circulation within an indoor environment—independent of particle removal pathways, including ventilation and / or outdoor air circulation, precipitation, filtration, dilution, etc., and selectively suggest modifications to each of these removal pathways to improve air removal, minimize costs associated with air removal, and meet and / or exceed target particle and / or gas airflow values ​​defined for the aerosol zone.

[0019] 4.Tracer Detection System Generally, the tracer detection system 100 includes a set of tracer dispensers 110 and a set of sensor units 120 temporarily deployed within a facility for the performance of one or more tracer tests. In particular, the tracer detection system 100 includes a set of tracer dispensers 110 (e.g., one or more tracer dispensers 110) configured to emit known amounts (e.g., number, concentration, volume) of tracers in solution (i.e., tracer test load) into the air within a defined indoor environment (hereinafter "aerosol zone") that includes the set of tracer dispensers 110, and a set of sensor units 120 (e.g., one or more sensor units 120) configured to detect the tracers in the air with the set of sensor units 120 and record the amount of these tracers over time.

[0020] More specifically, the tracer detection system 100 may include a set of tracer dispensers 110 and a set of sensor units 120 deployed within an aerosol zone, such as within a single defined aerosol zone (e.g., an office, a classroom, a kitchen, a hallway) and / or across multiple zones (e.g., a series of offices, a floor of a building, adjacent classrooms, multiple stores in a shopping mall). Each tracer dispenser 110 in the set of tracer dispensers 110 can be configured to periodically emit a known amount of tracer (i.e., a tracer test load) into the surrounding environmental air, and each sensor unit 120 in the set of sensor units 120 can be configured to absorb the surrounding environmental air and detect the presence of a tracer (e.g., aerosolized tracer particles, tracer gas) present in the absorbed environmental air via a set of sensors 122 (e.g., particle or aerosol sensors, gas sensors) integrated within the sensor unit 120, including aerosolized tracer particles (or "aerosol tracers") and / or tracer gas emitted by the set of tracer dispensers 110.

[0021] Furthermore, the tracer detection system 100 includes (or is connected to) a computer system—such as a local computer system located within the facility (e.g., a local server or controller 124) or a remote computer system (e.g., a computer network)—connected to the set of tracer dispensers 110 and / or the set of sensor units 120 via wired or wireless connections. The computer system can be configured to interface with the set of tracer dispensers 110 and the set of sensor units 120 to execute the blocks of method S100. For example, the computer system can selectively activate a tracer dispenser 110 of the set of tracer dispensers 110 to trigger the emission of a tracer test load, and selectively activate a sensor unit 120 of the set of sensor units 120 to trigger the set of sensors 122 to capture a time series of aerosol amounts in the air passing through the sensor unit 120.

[0022] In one variation, the tracer detection system 100 can further include a display—such as integrated with the tracer dispenser 110 and / or one or more sensor units 120—configured to depict results, prompts, and / or status (e.g., generated by a computer system). For example, the tracer dispenser 110 can include a display configured to indicate a current status of the tracer dispenser 110, such as during, immediately before, immediately after, and / or during a tracer release; depict instructions to a user corresponding to the current status; depict a set of airflow values—such as a current air exchange rate, a current aerosol clearance rate, a current exposure reduction rate, a current infection exposure risk, a current composite risk score, etc.—derived by the computer system for a previous tracer release; depict prompts to modify and / or adjust environmental controls within the space; and / or depict prompts to modify and / or adjust the ventilation system within the space.

[0023] Additionally and / or alternatively, in another variation, the tracer detection system 100 may interface with a user portal (e.g., a native application, a web application) running on a user computing device—such as a smartphone, tablet, desktop computer, etc.—to communicate results, prompts, and / or system status to a user or group of users associated with the facility.

[0024] In one variation, the tracer detection system 100 may include a set of airflow regulators—deployed proximate to, coupled to, integrated with, etc.—the tracer dispenser 110 and / or the sensor unit 120—configured to regulate the flow of aerosolized tracer within the environment. For example, the tracer detection system 100 may include a fan proximate to and / or integrated with the tracer dispenser 110 and configured to direct the flow of aerosolized tracer—released by the tracer dispenser 110—in a particular direction, such as upward into the airflow and / or toward a particular sensor unit 120, or toward a space within a facility containing the tracer dispenser 110. Additionally and / or alternatively, in another example, the tracer detection system 100 may include a fan proximate to and / or integrated into the sensor unit 120 and configured to direct a flow of aerosolized tracer in the air toward an inlet of the sensor unit 120 and / or promote mixing of the aerosol in the air surrounding the sensor unit 120.

[0025] Further, in one implementation, the sensor unit 120 and the tracer dispenser 110 can be configured to wirelessly communicate with each other. For example, the tracer dispenser 110 can be configured to automatically trigger the sensor unit 120 to begin recording time-series tracer data via the set of sensors 122 in response to receiving a command from a computer system—such as in preparation for or in response to dispersing a tracer test load. Additionally and / or alternatively, in another example, the sensor unit 120 can be configured to automatically trigger the tracer dispenser 110 to dispense a tracer test load in response to receiving a command from the computer system and / or based on a dispersal schedule or protocol loaded into the (local) controller 124 of the sensor unit 120—in preparation for or in response to beginning to capture aerosol data by the set of sensors 122.

[0026] 4.1 Tracer dispenser The tracer detection system 100 may include one or more tracer dispensers 110 configured to be temporarily installed within the aerosol zone to dispense a known amount of tracer (e.g., salt, volatile organic compound, fluorescent material, genetic material) into the air within the aerosol zone.

[0027] Generally, tracer dispenser 110 (hereinafter "dispenser 110") may include a reservoir 112 configured to store a tracer in solution, an outlet fluidly connected to reservoir 112, and an actuator 116 configured to dispense the tracer test load from reservoir 112 and through the outlet for release into the aerosol zone. Dispenser 110 may also include a dispenser power supply 118 (e.g., a battery pack, an external power source) configured to temporarily provide power to actuator 116 for dispensing the tracer test load from reservoir 112.

[0028] The dispenser 110 can be configured to output a tracer test load including a known volume and a known concentration of tracer, such that the system can compare the detected tracer level (e.g., tracer number, tracer concentration) to the actual tracer level (e.g., based on the known volume and known concentration) in the tracer test load released by the dispenser 110. Furthermore, the dispenser 110 can be configured to intermittently release the tracer test load into a space, such as at a target frequency and / or coordinated with the collection of air samples by the sensor unit 120. The system can then utilize these tracers as markers in the air samples absorbed by the sensor unit 120. In particular, the dispenser 110 can be configured to output a set of tracers configured to mimic the flow, dispersion, and / or dissipation of pathogens within a space (e.g., output in human saliva). For example, the dispenser 110 can be configured to output a set of tracers, each tracer in the set configured to mimic a specific pathogen in a set of pathogens detectable in the space. In one example, the tracer test load can include a first tracer exhibiting size (e.g., relatively small size) in a first size range that matches a pathogen exhibiting size in the first size range, a second tracer exhibiting size (e.g., relatively large size) in a second size range that matches a pathogen exhibiting size in the second size range, and a third tracer exhibiting size (e.g., relatively medium size) in a third size range between the first and second size ranges. Thus, the system can leverage detection of these tracers—which may exhibit different flow or dispersion patterns in the space based on the size of the tracers—to better predict the flow or dispersion of pathogens of different sizes in the space.

[0029] In one implementation, the dispenser 110 is configured to receive a replaceable cartridge (i.e., reservoir 112) loaded with a set of tracer samples (e.g., highly concentrated tracer samples) for dispensing into space a particular tracer contained in the set of tracer samples in the cartridge. Over time, the cartridge can be replaced to replenish the supply of tracer samples available for dispensing by the dispenser 110 and / or to supply a different type of tracer sample to the dispenser 110.

[0030] In one example, the dispenser 110 may include a cartridge receptacle, a loading container configured to prepare a tracer test load—containing a known concentration of tracer in a known volume of aqueous solution (e.g., a saltwater solution), a fluid reservoir 112 configured to supply a measured volume of the aqueous solution to the loading container, and a sprayer (e.g., a nebulizer) fluidly connected to the loading container and configured to emit aerosolized (suspended) droplets of the tracer test load into the air in the space. In this implementation, the dispenser 110 can be configured to receive a replaceable (e.g., disposable) cartridge that includes an array of tracer reservoirs 112 (e.g., blister reservoirs 112, capsules, compartments) each loaded with a small-volume, highly concentrated tracer test load containing a tracer of a particular size (e.g., within a narrow size range and / or a variety of sizes), concentration, and / or identity (e.g., genetic identity), and a connector configured to temporarily engage a cartridge receptacle and place the array of tracer reservoirs 112 within the dispenser 110. The dispenser 110 can then selectively release one or more tracer test loads into the loading vessel such that combination with a larger volume of aqueous solution produces a tracer test load indicating a particular concentration and identity of the tracer. The dispenser 110 can then release this tracer test load into space via a spray. Thus, the dispenser 110 can be configured to adjust and / or track the tracer concentration, tracer identity, and / or tracer size of the dispensed tracer test load.

[0031] In one implementation, the dispenser 110 is configured to dispense a tracer test load including a known concentration of salt in solution. In another implementation, the dispenser 110 is configured to dispense a tracer test load including a known concentration of volatile organic compounds (e.g., IPA) in solution. In another implementation, the dispenser 110 is configured to dispense a tracer test load including a known concentration of fluorescent material in solution. In yet another implementation, the dispenser 110 is configured to dispense a tracer test load including a known concentration of genetic material (e.g., DNA barcodes) in solution. Nevertheless, the dispenser 110 can be configured to output a tracer test load including any type and / or combination of detectable tracers, such as any tracer particle, liquid tracer, tracer gas, genetic tracer including DNA (e.g., DNA barcodes), fluorescent tracer including fluorescent material, salt, etc.

[0032] In one variation, the dispenser may further include a dispenser communication module 114 configured to receive commands from the computer system. In this variation, the actuator 116 may be configured to temporarily release a tracer test load—including the tracer aerosolized in solution—from the reservoir 112 and into the indoor environment based on commands received by the dispenser communication module 114.

[0033] 4.1.1 Tracer Types In general, the dispenser 110 can be configured to temporarily dispense a tracer test load containing a known concentration of a tracer (eg, an aerosol tracer, a tracer gas).

[0034] In one implementation, the dispenser 110 can be configured to temporarily dispense a metered volume of a tracer test load containing an aerosol tracer (or “aerosolized tracer particles”). In particular, in this implementation, the tracer detection system 100 includes a dispenser 110 temporarily installed (and / or configured to be temporarily installed) at a dispenser 110 location within the aerosol zone, the dispenser 110 including a reservoir 112 containing—or configured to receive and store—a non-volatile tracer in solution, and an actuator 116 configured to release a tracer test load—containing a known or “test” concentration of aerosol tracer (e.g., derived from the non-volatile tracer in solution in the reservoir 112) from the reservoir 112 and into the aerosol zone (e.g., via an outlet). In particular, in this implementation, the dispenser 110 can be configured to atomize a volume of the non-volatile tracer in solution—temporarily stored in the reservoir 112—for release into the ambient air via the actuator 116. For example, the dispenser 110 can be configured to store a large volume of tracer solution containing a known concentration of salt particles (e.g., NaCl) in solution and to release a metered volume of the aerosolized salt particles into the air within an aerosol zone that includes the dispenser 110.

[0035] Additionally or alternatively, in another implementation, the dispenser 110 can be configured to temporarily dispense a metered volume of a tracer test load containing a tracer gas (or “gaseous tracer particles” or “gas tracer”). In particular, in this implementation, the tracer detection system 100 includes a dispenser 110 temporarily installed (and / or configured to be temporarily installed) at a dispenser 110 location within the aerosol zone, the dispenser 110 including a reservoir 112 containing—or configured to receive and store—a volatile tracer (e.g., a volatile organic compound) in solution, and an actuator 116 configured to release (e.g., via an outlet) a tracer test load containing a known or “test” concentration of tracer gas (e.g., derived from the volatile tracer in solution in the reservoir 112) from the reservoir 112 and into the aerosol zone. In particular, in this implementation, the dispenser 110 can be configured to release a quantity of a volatile tracer in solution—temporarily stored in the reservoir 112—for release as a tracer gas into the surrounding air via the actuator 116. For example, the dispenser 110 can be configured to store a quantity of a tracer solution containing a known concentration of a volatile tracer (e.g., isopropyl alcohol)—including one or more volatile organic compounds, for example—in solution, and to release a metered volume of the tracer gas—derived from the tracer solution—into an aerosol zone containing the dispenser 110.

[0036] Additionally or alternatively, in yet another implementation, the dispenser 110 can be configured to temporarily dispense a measured volume of a tracer test load containing an aerosol tracer and a tracer gas. In particular, in this implementation, the tracer detection system 100 includes a dispenser 110 temporarily installed (and / or configured to be temporarily installed) at a dispenser 110 location within the aerosol zone, the dispenser 110 including a reservoir 112 containing—or configured to receive and store—a mixture of a volatile and a non-volatile tracer in solution, and an actuator 116 configured to release (e.g., via an outlet) a tracer test load from the reservoir 112 and into the aerosol zone, the tracer test load comprising a first concentration of aerosol tracer and a second concentration of tracer gas. In particular, in this implementation, the dispenser 110 can be configured to release a quantity of the volatile and non-volatile tracers in solution—temporarily stored in the reservoir 112—for dispersal as the aerosol tracer and the tracer gas into the ambient air via the actuator 116. For example, the dispenser 110 can be configured to store a large volume of tracer solution containing a known concentration of salt (e.g., NaCl) and a known concentration of isopropyl alcohol (or "IPA") in solution, and to release a measured volume of tracer test load—containing salt aerosol (or "aerosolized salt") and IPA gas at known concentrations—into an aerosol zone containing the dispenser 110.

[0037] 4.2 Sensor unit The tracer detection system 100 may include one or more sensor units 120 that are temporarily placed within the aerosol zone and configured to detect the presence of airborne tracers at these sensor units 120 (e.g., surrounding, absorbed by).

[0038] In one implementation, the sensor unit 120 includes a set of sensors 122 configured to detect the presence of a set of tracers in air flowing over and / or through the sensor unit 120; a sensor communication module 124 configured to receive commands from a computer system, offload time-series tracer data (e.g., time-series concentrations of the tracers) to the computer system, and / or enable communication (e.g., via Wi-Fi) between the sensor unit 120 and a computer system (e.g., a remote computer system, a local server) where other sensor units 120 in the network of sensor units 120 are deployed in a space and / or where a set of dispensers 110 are installed in an aerosol zone; a controller 124 configured to read signals output by the set of sensors 122 and interpret the time-series amounts (e.g., concentrations) of the tracers in the air at the sensor unit 120 based on these signals; and a power module 128 configured to provide power to the controller 124, the first set of sensors 122, and / or the sensor communication module 124.

[0039] Typically, the sensor unit 120 is configured for temporary or semi-permanent installation in a particular environment (e.g., an isolated space within a building), such as being mounted on a stand, fixed to a wall, and / or standing on the floor of a particular room. Alternatively, the sensor unit 120 can be coupled to a mobile device (e.g., a manual or autonomous cart, an autonomous aerial vehicle) configured to transport the sensor unit 120 near a space or facility.

[0040] Once deployed in a particular space (e.g., permanently or temporarily installed), the sensor unit 120 can absorb air from the space over time and, in response to commands received by the sensor communication module 124 and / or at a targeted frequency (e.g., once a day, once an hour, once a minute, continuously), etc., draw this air via the set of sensors 122 for detection of tracers in air samples collected from the aerosol zone.

[0041] Additionally, the tracer detection system 100 may include multiple sensor units 120 installed throughout a particular facility (e.g., one per floor of an office building). For example, the system may include a docking station (e.g., a charging docking station) configured to house a set of sensor units 120, such that each sensor unit 120 can be deployed from the docking station to a particular space (e.g., office, classroom, shop, bathroom) within a larger facility (e.g., office building, school, mall, airport).

[0042] In one variation, the sensor unit 120 includes a set of indicators—such as disposed on the exterior (e.g., of the housing) of the sensor unit 120. In this variation, the set of indicators can be configured to signal detection of a tracer—such as of a particular tracer type—at the sensor unit 120 during the performance of a tracer test. The sensor unit 120 can thus include a set of indicators for signaling to an operator present in the bioaerosol zone the initial detection of a tracer at the sensor unit 120 during the performance of a tracer test and / or the completion of the tracer test. For example, the sensor unit 120 can include a set of colorimetric sensors configured to output an optical signal representative of the amount of tracer of the tracer type detected at the set of colorimetric sensors.

[0043] 4.2.1 Sensor unit type In general, the sensor unit 120 can be configured to temporarily record time-series tracer data representing the concentration of the tracer in the air at (e.g., flowing over, near, or through) the sensor unit 120, such as in response to a command received by the sensor communication module 124 to initiate a tracer test.

[0044] In one implementation, the tracer detection system 100 includes a sensor unit 120 configured to sample air from an aerosol zone and detect aerosol particles present in the air to record time-series aerosol data representative of the amount of aerosol (or “aerosol particles”) detected in the air at the sensor unit 120 over a particular sampling period, etc. In this implementation, the sensor unit 120 (e.g., a particle or aerosol detector) can be configured to draw air from the aerosol zone via a set of aerosol sensors 122 (e.g., particle sensors) for detection of aerosol particles—including aerosol tracers released into the external environment by the dispenser 110—present in the air at the sensor unit 120. In particular, the sensor unit 120 can include a set of aerosol sensors 122 configured to temporally generate signals—at a fixed or target frequency (e.g., every 100 millisecond interval, every 200 millisecond interval, every 1 second interval), etc.—representing the amount of aerosol particles (e.g., aerosol) present in the air absorbed by the sensor unit 120. The controller 124 can then interpret the time series aerosol data - representing the amount (e.g., concentration, number) of aerosol particles detected in the air by the set of aerosol sensors 122 - based on the signals read from the set of aerosol sensors 122, store this time series aerosol data in a local memory 129 (e.g., a buffer), and / or offload the time series aerosol data to a computer system - such as continuously in (near) real time and / or from the local memory 129 at a particular frequency.

[0045] In another implementation, the tracer detection system 100 includes a sensor unit 120 configured to sample air from the aerosol zone and detect tracer gas present in the air for recording time-series gas data representative of the amount of tracer gas detected in the air at the sensor unit 120. In this implementation, the sensor unit 120 can be configured to draw air from the aerosol zone via a set of gas sensors 122 (e.g., one or more gas sensors 122) for detection of tracer gas—released to the external environment by the dispenser 110—present in the air at the sensor unit 120. In particular, the sensor unit 120 can include a set of gas sensors 122 configured to temporally generate a signal—at a fixed or target frequency (e.g., every 100 millisecond interval, every 200 millisecond interval, every 1 second interval), etc.—representing the amount of tracer gas present in the air that has been absorbed by the sensor unit 120. The controller 124 can then interpret time series gas data based on the signals read from the set of gas sensors 122, which represents the amount (e.g., concentration, number) of tracer gas detected in the air by the set of gas sensors 122.

[0046] In yet another implementation, the tracer detection system 100 includes a sensor unit 120 configured to sample air from an aerosol zone and detect both aerosol particles and tracer gas present in the air for recording time-series tracer data—including time-series aerosol data and time-series gas data—representing the amounts of aerosol particles and tracer gas detected in the air at the sensor unit 120. In this implementation, the sensor unit 120 can be configured to draw air from the aerosol zone through a set of aerosol sensors 122 (e.g., one or more particle sensors) for detection of aerosol particles present in the air at the sensor unit 120, and to draw air from the aerosol zone through a set of gas sensors 122 (e.g., one or more gas sensors 122) for detection of tracer gas present in the air at the sensor unit 120. The controller 124 can then interpret time-series aerosol data based on signals read from the set of aerosol sensors 122, representing the amount (e.g., concentration, number) of aerosol particles detected in the air by the set of aerosol sensors 122, and interpret time-series gas data based on signals read from the set of gas sensors 122, representing the amount (e.g., concentration, number) of tracer gas detected in the air by the set of gas sensors 122.

[0047] 5. Tracer Detection System Deployment Generally, the tracer detection system 100 can be temporarily deployed in an aerosol zone for the performance of tracer tests within this aerosol zone.

[0048] In particular, the tracer detection system 100—including a set of dispensers 110 and a set of sensor units 120—can be temporarily positioned in a target configuration within a particular aerosol zone (e.g., a room, office, hallway) for performing a tracer test during a test period. During this test period, the system can trigger the release of a tracer test load—including a known amount of aerosol tracer (e.g., aerosolized salt particles)—into the air within the aerosol zone by one or more dispensers 110 of the set of dispensers 110 positioned within the aerosol zone, and record time-series aerosol data—representing the concentration of aerosol particles in the air—via a set of sensors 122 integrated into one or more sensor units 120 of the set of sensor units 120 positioned within the aerosol zone. The system can then utilize this time-series aerosol data—collected during the execution of the aerosol tracer test—to derive insights regarding the airflow (e.g., removal and / or exchange rates, airflow direction) and / or the flow of the aerosol tracer (e.g., decay rate, flow direction) within the aerosol zone.

[0049] In one implementation, the tracer detection system 100—including one or more dispensers 110 and one or more sensor units 120—can be temporarily deployed to and installed within an aerosol zone for a test period of a target duration (e.g., 10 minutes, 30 minutes, 1 hour, 24 hours) for performing a tracer test and / or a series of tracer tests during the test period. Once installed within the aerosol zone, the system can perform the tracer tests as appropriate and interpret a set of airflow values ​​for the aerosol zone based on the time-series aerosol data recorded during the tracer test. The tracer detection system 100 can then be removed from the aerosol zone upon completion of the tracer test or series of tracer tests—such as for installation in another aerosol zone within the facility and / or storage elsewhere.

[0050] For example, an operator associated with the aerosol zone can place a dispenser 110 and a set of sensor units 120 within the aerosol zone (e.g., in a target configuration) in preparation for conducting tracer tests. Once deployed within the aerosol zone, the system can initiate a test period of a target duration (e.g., 10 minutes, 30 minutes, 1 hour, 24 hours), perform one or more tracer tests within the test period—including the release of a tracer test load by the dispenser 110 and the recording of time-series aerosol data by the sensor units 120—and output (near) real-time results for each tracer test—such as airflow values ​​(e.g., air exchange range, aerosol reduction rate, air velocity and / or direction), risk levels associated with one or more pathogens, and the effectiveness of various interventions or environmental controls (e.g., HVAC settings, occupancy levels, activity levels).

[0051] In one example, the system may trigger the dispersal of a tracer test load to initiate a tracer test, derive a tracer signal from time-series aerosol data collected while the tracer test is running, derive a set of airflow values ​​representing the flow and / or movement of aerosols within the aerosol zone based on the tracer signal, and report these airflow values ​​and / or additional insights in (near) real time to managers concerned with the aerosol zone. In this example, the system may thus derive deep insights into the flow and movement of aerosols within the aerosol zone through the running of (relatively) simple tracer tests (e.g., 10-minute tests, 20-minute tests, 1-hour tests).

[0052] Alternatively, in another implementation, tracer detection system 100—including a set of dispensers 110 (e.g., one or more dispensers 110) and a set of sensor units 120 (e.g., one or more sensor units 120)—can be deployed to a facility for permanent or semi-permanent installation within one or more aerosol zones within the facility. In this implementation, once initially installed, the system can periodically perform tracer tests within the aerosol zones and / or within the facility as described above, based on a dispenser schedule (or “test schedule”) defined for the facility, and / or in response to environmental changes detected within the facility, etc.

[0053] 5.1 Tracer Detection System: Configuration Generally, as described above, the tracer detection system 100 can be set up in a target configuration within the aerosol zone in preparation for performing a tracer test.

[0054] For example, the tracer detection system 100 can be deployed in a target configuration that defines the number and / or placement of a set of dispensers 110 (e.g., one or more dispensers 110) temporarily installed within the aerosol zone for performing tracer tests - defining the location of the set of dispensers 110 - and the number and / or placement of a set of sensor units 120 (e.g., one or more sensor units 120) temporarily installed within the aerosol zone for performing tracer tests - defining the location of the set of sensor units 120.

[0055] 5.1.1 Tracer detection system configuration: 1 sprayer + 1 sensor unit Generally, as described above, the tracer detection system 100 can be deployed in a target configuration within the aerosol zone in preparation for performing a tracer test.

[0056] In one implementation, the tracer detection system 100 includes a first dispenser 110 configured to temporarily dispense a tracer test load containing a known concentration of aerosol tracer particles positioned at a first dispenser 110 location within the aerosol zone, and a first sensor unit 120 positioned at a first unit location within the aerosol zone and configured to temporarily capture time-series aerosol data representative of the presence of aerosol particles in the air at the first dispenser 110 location.

[0057] In particular, the first dispenser 110 can be positioned at a first dispenser 110 location that is offset by a distance that falls within the target distance range. For example, to install the tracer detection system 100 in preparation for a tracer test, a user (e.g., a human operator) can place the first dispenser 110 at a first dispenser 110 location (e.g., defined by a computer system and / or manually selected by an operator), such as at the center of the aerosol zone and / or at a location expected to exhibit minimal airflow fluctuations or turbulence (e.g., relative to the aerosol zone), place the first sensor unit 120 at a first unit location expected to intersect with the flow path of the aerosolized tracer released from the first dispenser 110, and verify the connection (e.g., wired or wireless) of the first dispenser 110 and / or first sensor unit 120 to the computer system. The operator can then initiate the tracer test, such as by manually engaging the actuator 116 of the first dispenser 110 and / or by triggering the start within a web or native application running on the user's computing device and connected to the computer system.

[0058] In particular, the operator can place the first sensor unit 120 at a first sensor location that defines a distance from the first dispenser 110 location within a target distance range defined for the aerosol zone (e.g., 1 to 2 feet, 6 to 8 feet, 1 to 2 meters). Thus, by placing the first sensor unit 120 at a specific distance—within the target distance range—from the first dispenser 110, the first sensor unit 120 can be configured to absorb and detect aerosolized tracer emitted by the first dispenser 110 in the tracer test load, which indicates an aerosol velocity within a threshold deviation of the air velocity at the first sensor unit 120 and indicates a relatively high concentration, thereby minimizing errors in the quantification of the aerosolized tracer at the first sensor unit 120 and maximizing the signal-to-noise ratio by increasing the amount of aerosolized tracer present at the first sensor unit 120.

[0059] For example, the first dispenser 110 can be configured to emit a tracer test load—including aerosolized tracers—into the aerosol zone, such that these aerosolized tracers exhibit an initial aerosol velocity that exceeds the air velocity in the aerosol zone. The first sensor unit 120 can therefore be placed at at least a minimum distance from the first dispenser 110 to enable a reduction in the aerosol velocity before detection—such that upon detection, these aerosolized tracers exhibit an aerosol velocity within a threshold deviation of the air—thereby enabling accurate detection of the amount of aerosolized tracer at the first sensor unit 120. Furthermore, in this example, the first sensor unit 120 can be placed within a maximum distance from the first dispenser 110 to limit the variability of the aerosolized tracer in the aerosol zone before detection at the first sensor unit 120, thereby increasing the likelihood of detection of these aerosolized tracers at the first sensor unit 120.

[0060] Additionally, to further increase the detectability of the aerosolized tracer in the first sensor unit 120, the operator can place the first sensor unit 120 at a first unit location that defines an orientation - relative to the first dispenser 110 location - that corresponds to the direction of the aerosol flow from the first dispenser 110.

[0061] In one variation, a user can manually perform a directionality test within the aerosol zone to predict a first unit location for the first sensor unit 120—before installing the first sensor unit 120 within the aerosol zone. For example, the user can place the first sensor unit 120 within the first unit location, manually trigger the release of a tracer test load (e.g., for a shortened dispensing period), and visually inspect the flow of aerosolized tracer in the tracer test load outward from the first dispenser 110 to identify the primary direction and / or path of the aerosol flow from the first dispenser 110. The operator can then place the first sensor unit 120 at a first unit location that intersects with this path of the aerosol flow from the first dispenser 110. Therefore, by placing the first sensor unit 120 along this path of the aerosol flow, the first sensor unit 120 can be configured to initially absorb the aerosolized tracers dispersed within the tracer test load at a minimum duration from the initial release of these aerosolized tracers by the first dispenser 110, thereby reducing the time to detection following dispersion, and to detect, via the set of sensors 122, a maximum amount (e.g., concentration) of aerosolized tracers at the initial time of detection - such as before increased dissipation of the aerosolized tracers within the aerosol zone - thereby improving the signal-to-noise ratio of the resulting tracer signal.

[0062] 5.1.2 Tracer detection system configuration: 1 sprayer + multiple sensor units Additionally or alternatively, in another implementation, the tracer detection system 100 may include a first dispenser 110 positioned at a first dispenser 110 location within the aerosol zone, and a set of sensor units 120 temporarily positioned at a set of unit locations - defining a target placement near the first dispenser 110 - configured to temporarily capture time-series aerosol data representative of the presence of aerosol particles in the air at the locations of the set of dispensers 110.

[0063] In particular, in this implementation, the tracer detection system 100 can include a first dispenser 110 temporarily positioned at a first dispenser 110 location, a first sensor unit 120 temporarily positioned at a first unit location within the aerosol zone, and a second sensor unit 120 temporarily positioned at a second unit location within the aerosol zone. Additionally, the tracer detection system 100 can include additional sensor units 120 positioned within the aerosol zone, including a third sensor unit 120 temporarily positioned at a third unit location within the aerosol zone, a fourth sensor unit 120 temporarily positioned at a fourth unit location within the aerosol zone, etc.

[0064] In one example, the first dispenser 110 may be positioned at a first dispenser 110 location that defines the approximate center of the room, such as within a threshold distance of the center of the room. The set of sensor units 120 can include a first sensor unit 120 positioned at a first unit location that offsets the first dispenser 110 location by approximately (e.g., within 5 percent, within 20 percent) a first distance; a second sensor unit 120 positioned at a second unit location that offsets the first dispenser 110 location by approximately the first distance and the first unit location by approximately the second distance; a third sensor unit 120 positioned at a third unit location that offsets the first dispenser 110 location by approximately the first distance and the second unit location by approximately the second distance; and a fourth sensor unit 120 positioned at a fourth unit location that offsets the first dispenser 110 location by approximately the first distance, offsets the third unit location by approximately the second distance, and offsets the first unit location by approximately the second distance.

[0065] The first, second, third, and fourth sensor units 120 can therefore be arranged in a square configuration near the dispenser 110 located at the first dispenser 110 location in the center of the room - with each sensor unit 120 offset from adjacent sensor units 120 by approximately a second distance.

[0066] In one variation, the tracer detection system 100 can be arranged in a target configuration that defines a number of sensor units 120 corresponding to the size (e.g., area, volume) of the aerosol zone. For example, the tracer detection system 100 can include a first dispenser 110 and a set of sensor units 120 temporarily arranged in a target configuration within the aerosol zone that defines a set of discrete regions of approximately equivalent size (e.g., within 5 percent, 10 percent, 20 percent) (e.g., volume, area, cross-sectional area). In this example, each sensor unit 120 of the set of sensor units 120 can be temporarily installed in a specific discrete region of the set of discrete regions, such that the target configuration defines a number of sensor units 120—of the set of sensor units 120—that corresponds to the number of discrete regions of the set of discrete regions.

[0067] 5.2 Variation: Target Configuration Calculation In one variation, the system can automatically calculate a target configuration for the first sensor unit 120 and the first dispenser 110 within the aerosol zone and prompt the operator to place the first sensor unit 120 and the first dispenser 110 in this target configuration in preparation for the tracer test. For example, the system can access a set of zone characteristics defined for the aerosol zone—such as dimensions, total volume, layout, and a set of activity types or types (e.g., office work, exercise, singing, eating) associated with the aerosol zone—and a set of environmental controls (e.g., current and / or historical environmental controls) defined for the aerosol zone—such as a current or average occupancy level, a duration of human occupancy, and a set of HVAC and / or ventilation settings—and calculate a target configuration—defining a first dispenser 110 location and a first unit location—for deployment of the tracer detection system 100 within the aerosol zone based on the target distance range, the set of zone characteristics, and / or the set of environmental controls.

[0068] Additionally and / or alternatively, in this implementation, the system can calculate a first dispenser 110 location based on the set of zone characteristics and / or the set of environmental controls, generate a prompt to perform a directionality test in the aerosol zone before installing the first sensor unit 120 in the aerosol zone, transmit the prompt to an operator, and, in response to confirming that the directionality test was performed, prompt the user to specify a direction of aerosol flow from the first dispenser 110. Based on this direction and the first dispenser 110 location, the system can then calculate a first unit location, generate a prompt to place the first sensor unit 120 at the first unit location, and transmit the prompt to the operator.

[0069] 5.3 Variant: Setup Verification In another variation, the system can verify the setup configuration of the tracer detection system 100 within the aerosol zone before performing a tracer test. For example, the system can generate a prompt to confirm deployment of the first dispenser 110 and the first sensor unit 120 within the aerosol zone and transmit the prompt to an operator associated with the aerosol zone via a mobile device (e.g., a smartphone, a tablet) accessed by the operator, or via a display connected to and / or integrated with the first dispenser 110 and / or the first sensor unit 120, etc. Then, in response to receiving confirmation of deployment from the operator, the system can access a first geolocation of the first sensor unit 120 within the aerosol zone (e.g., via an RSS-based location technique), access a second geolocation of the dispenser 110 within the aerosol zone, and calculate the distance between the first and second geolocations. Then, in response to the distance falling within the target distance range defined for the aerosol zone, the system can verify the setup configuration and enable execution of a tracer test within the aerosol zone. Alternatively, in response to the distance not falling within the target distance range defined for the aerosol zone, the system can generate and transmit a prompt to an operator to adjust (e.g., increase or decrease) the distance between the dispenser 110 and the sensor unit 120. The system can then repeat this process until the distance falls within the target distance range.

[0070] 5.4 Test Setup Data In one implementation, the system can access a set of setup data representing the setup configuration to be implemented during the execution of the tracer test in the aerosol zone. In particular, in this implementation, the system can access a set of test setup data—including dispenser 110 and / or sensor configuration data, characteristics of the aerosol zone (e.g., size, average occupancy level, location of various objects in the aerosol zone), a set of current HVAC settings employed by an HVAC system installed in the aerosol zone, etc.—captured prior to the execution of the tracer test in the aerosol zone, and write this set of test setup data into a test data packet generated for this particular tracer test and stored in the generated zone profile for the aerosol zone.

[0071] For example, the system may access a set of zone characteristics defined for the aerosol zone, such as size (e.g., area, volume, height, width, length), number and / or location of windows, vents, doorways, etc., current occupancy level, access the arrangement (or "configuration") of the set of sensor units 120 and / or set of dispensers 110 within the aerosol zone, which defines the location of each dispenser 110 and / or sensor unit 120 within the aerosol zone, the horizontal and / or vertical distance between each dispenser 110 and each sensor unit 120, the horizontal and / or vertical distance between each sensor unit 120 installed within the aerosol zone and each other sensor unit 120, etc., and / or access a set of historical and / or current conditions within the aerosol zone, including HVAC settings (e.g., ventilation rate), occupancy level, activity type assigned to the aerosol zone (e.g., exercising, working, eating, talking, singing), etc.

[0072] In one example, the system can access an image (e.g., a 2D or 3D image) of the aerosol zone—such as captured via a mobile device accessed by an operator—and extract a set of test setup data based on features detected in the image. Additionally or alternatively, in another example, the system can access a set of laser sensor data—such as captured manually by an operator inspecting the aerosol zone via a laser sensor device and / or by a laser sensor installed in sensor unit 120 and / or dispenser 110—and extract a set of test setup data based on the set of laser sensor data. Additionally or alternatively, in yet another example, the system can prompt the operator to manually upload a set of setup data defined for the aerosol zone.

[0073] 6. Tracer Test: Aerosol Data Collection Block S110 of method S100 recites recording a first time series of aerosol data - representing the concentration of aerosol particles present in the air at the first unit location during the first test period - via a set of sensors 122 integrated into a first sensor unit 120 temporarily positioned at a first unit location within the aerosol zone during the first test period, during the performance of a first tracer test within a first test period.

[0074] Generally, in block S110, the sensor unit 120 may access a set of sensors 122 (e.g., a set of particle sensors) configured to signal the presence of aerosol particles in the air at the set of sensors 122 and record aerosol data at a series of target time increments. In particular, the computer system may trigger a first sensor unit 120 to begin recording a time series of aerosol data via the set of sensors 122 at a first time during a first test period and continue to record the time series of aerosol data throughout the remainder of the first test period.

[0075] In one implementation, the computer system can return a command to the sensor unit 120—e.g., via the sensor communications module 124—to begin recording a time series of aerosol data via the set of sensors 122. For example, in response to receiving confirmation from an operator (e.g., via a user's mobile device) to begin a tracer test, the computer system can generate a command to begin the tracer test and transmit this command to the sensor unit 120 via the sensor communications module 124. The sensor unit 120 can then receive the command from the computer system (e.g., via the sensor communications module 124), trigger the set of sensors 122 to begin recording time series aerosol data at a fixed sampling frequency (e.g., at 100 microsecond intervals, 200 microsecond intervals, 1 second intervals), and offload the time series of aerosol data to the computer system in real time or intermittent data packets, etc.

[0076] In this implementation, the sensor unit 120 can record aerosol data continuously and / or semi-continuously, such as every 100 millisecond, 200 millisecond, or 1 second interval. Additionally or alternatively, the sensor unit 120 can selectively sample aerosol data intermittently (e.g., once per 1 second interval, once per 5 second interval, once per 30 second interval) to reduce power consumption and minimize data files, such as before the completion of a dispensing period. In each of these implementations, the sensor unit 120 can then transmit the aerosol data to a computer system at a particular logging frequency (e.g., once per 1 second, once per 15 second interval, once per 30 second interval).

[0077] In particular, the sensor unit 120 can record a time series of aerosol data as described above, write the time series of aerosol data to the sensor unit 120's local storage, and upload the aerosol data to a computer system (e.g., via the sensor communications module 124) at a target logging frequency. Generally, the sensor unit 120 can record packets of aerosol data for a fixed duration (e.g., 100 milliseconds, 1 second, 15 seconds, 1 minute), timestamp each packet of aerosol data, and wirelessly transmit each data packet to the computer system. The computer system can then combine a series of data packets received within a specific time window into a single file of aerosol data. The computer system can utilize the timestamp associated with each data packet to assemble a time series of data packets representing the time-series aerosol data collected throughout the duration of the first test period.

[0078] 6.1 Background period In one implementation, at the start of a test period, the computer system can trigger the sensor unit 120 to begin recording time-series aerosol data during a background period prior to the application period corresponding to the release of the tracer test load by the applicator 110. The computer system can then utilize this time-series aerosol data to interpret the background or "baseline" level (e.g., concentration, number) of aerosol particles in the aerosol zone, such as in the absence of aerosol particles added to the aerosol zone via the application of the tracer test load.

[0079] In this implementation, during a test period, the sensor unit 120 can record a time series of aerosol data—representing the concentration of aerosol particles in the air—throughout the duration of the test period. In particular, the system can record a first subset of the time series of aerosol data via a set of sensors 122 (e.g., aerosol sensors 122) integrated into the sensor unit 120 during a background period (e.g., within the test period) before the dispersal period, and derive a baseline concentration of aerosol particles present in the aerosol zone during the first test period based on the first subset of the first time series of aerosol data.

[0080] The sensors can then continue to record the time series of aerosol data throughout the test period to capture a second subset of the time series of aerosol data via the set of sensors 122 during a decay period following the dispersal period (e.g., to a target duration), and to derive a tracer concentration curve - for the tracer test - based on the second subset of the time series of aerosol data and the baseline concentrations.

[0081] 6.2 Spraying period Block S120 of method S100 recites triggering the release of a first tracer load into air within the aerosol zone by a dispenser 110 temporarily positioned at a dispenser 110 location within the aerosol zone - offset from the first unit location by a target distance - during a first dispensing period within a first test period, the first tracer load including a test concentration of aerosol tracer particles.

[0082] In general, the computer system can define a set of release parameters for a particular tracer test and / or a particular aerosol zone, such as the duration of the dispersal period corresponding to the release of the tracer test load, the start time of the dispersal period, the end time of the dispersal period, the aerosolization rate of the tracer dispensed from reservoir 112 and into the ambient air within the aerosol zone, the target discharge power for discharging the tracer test load from dispenser 110, the target aerosolization injection distance, the amount (e.g., concentration, number) of tracer to be dispensed within the tracer test load, and the tracer type (e.g., size, reactivity, class, specific molecule or particle). The system can then record the set of release parameters provided for the tracer test for combination with time-series aerosol data collected during the execution of the tracer test. For example, the system can store the set of release parameters for a particular tracer test in a test container among a set of test containers corresponding to the execution of the particular tracer test within the aerosol zone.

[0083] In one implementation, the computer system can return a command to the dispenser 110—such as via a communications module of the dispenser 110—to release a tracer test load over a distribution period according to a set of release parameters defined for this particular tracer test and / or this particular aerosol zone. In one example, the computer system can automatically return a command to the dispenser 110 to execute the release of the tracer test load according to the set of release parameters in response to verifying the setup of the aerosol detection system 100 in the aerosol zone. In another example, the computer system can return a command to the dispenser 110 to execute the release of the tracer test load according to the set of release parameters in response to receiving a request to initiate a tracer test from a user computing device accessed by an operator or any other user associated with the aerosol zone or the facility including the aerosol zone.

[0084] For example, the dispenser 110 can include a reservoir 112—such as a replaceable cartridge and / or a fixed reservoir 112—loaded with salt particles (e.g., NaCl particles) in solution. To initiate a tracer test, the computer system can return a command to the communication module of the dispenser 110 to release a tracer test load—including aerosolized salt particles in solution—for a dispenser period according to a set of release parameters, including a start time (e.g., initial dispense time) and a duration of the dispenser period. Then, at the specified start time, the actuator 116 of the dispenser 110 can aerosolize a metered volume of salt particles in solution—removed from the reservoir 112—for release into the air within the aerosol zone at a specified aerosolization rate for the duration of the dispenser period.

[0085] Additionally and / or alternatively, in another implementation, an operator can manually select a user control (e.g., a button, a switch) located on dispenser 110 configured to trigger the initiation of the tracer test. In this implementation, the computer system can receive a query for release parameters from dispenser 110, access a set of release parameters defined for the tracer test in the aerosol zone, and return a command to dispenser 110 to perform the release of the tracer test load according to the set of release parameters. Additionally and / or alternatively, the computer system can pre-load the set of release parameters into dispenser 110.

[0086] 7. Tracer Signal Analysis Block S130 of method S100 recites deriving a first tracer concentration curve representing the change in concentration of aerosol tracer particles at the location of the first sensor unit 120 during a first test period based on the first time series of aerosol data and the test concentration.

[0087] Generally, during a tracer test, the system may access time-series aerosol data from the sensor unit 120 at a target logging rate as described above and record this time-series aerosol data in a test container from a set of test containers generated for the tracer test. The system may then utilize a set of release parameters defined for the tracer test to identify a target sampling window (or "decay period") within the test period—defining an initial time and a final time—that corresponds to a tracer signal, and derive the tracer signal—as represented by a tracer concentration curve—based on the time-series aerosol data collected during this target sampling window.

[0088] In particular, the system can trigger the recording of a first time series of aerosol data via a set of sensors 122 integrated into the sensor unit 120 for the duration of a test period, where the first time series of aerosol data represents the amount of aerosolized particles in the ambient air absorbed by the first sensor unit 120 during the test period, and trigger the release of a tracer test load into the ambient air in the aerosol zone - over a dispersal period within the test period - according to a first set of release parameters including an initial dispersal time corresponding to the start of the dispersal period, a duration of the dispersal period, and / or a dispersal rate representing the rate of release of aerosolized tracer from the dispersal device 110 during the test period. Then, upon completion of the test period, the system can calculate a target sampling window based on the first set of emission parameters - defining an initial sampling time and a final sampling time - extract a second time series of aerosol data from the first time series of aerosol data - collected during the target sampling window - and derive a tracer concentration curve based on the second time series of aerosol data - representing the change in the amount of aerosol tracer in the air detected at the sensor unit 120 during the sampling window between the initial sampling time and the final sampling time.

[0089] In one implementation, the system can define a target sampling window to match the period of decay (e.g., exponential decay) of the amount of tracer of a tracer type detected at the sensor unit 120. In particular, in this implementation, the system can derive a tracer signal—such as a decay curve representing the decrease (e.g., exponential decay) in the amount of a first type of tracer over the target sampling window—based on time-series aerosol data collected by the sensor unit 120 during the target sampling window, where the initial sampling time corresponds to the maximum amount (e.g., concentration, number) of tracer of the tracer type and the final sampling time corresponds to the minimum or “baseline” amount of tracer of the tracer type. The system can thus derive a tracer signal or “curve” (e.g., decay curve, calibration curve) configured to model the change in the amount (e.g., concentration, number) of tracer of a particular tracer type over time through the target sampling window. For example, the system can derive an exponential decay curve representing the change in the amount (e.g., concentration) of tracer of a tracer type over time during the target sampling window.

[0090] In one example, the system can access a baseline amount of a tracer of a tracer type defined for the aerosol zone, such as that recorded during an initial time period within the test period - before the spraying period - and / or that derived for the aerosol zone during one or more preceding test periods; estimate, for each time point represented in the time series of bioaerosol data, the amount of tracer of the tracer type resulting from the tracer test load based on the difference between the amount of tracer recorded at the time point and the baseline amount of the tracer; identify a maximum amount of tracer of the first tracer type at a first time in the time series aerosol data; identify a final amount of tracer at a second time after the first time in the time series aerosol data - corresponding to the baseline amount and / or within a threshold deviation of the baseline amount; and select a target sampling window spanning from the first time to the second time. The system can then separate the time series of aerosol data collected during the selected sampling window and utilize statistical models and / or linear regression techniques - such as by performing a log-linear fit - to derive a tracer decay curve (i.e., tracer signal) that represents or models the decay over time of the amount of tracer of the tracer type detected by the sensor unit 120 during the sampling window.

[0091] In another implementation, the system can access a set of predefined rules for selecting a target sampling window within the aerosol zone, access a set of release parameters defined for the tracer test, and select the sampling window based on the predefined set of rules and the set of release parameters.

[0092] 7.1 Background period + spraying period + release period + decay period In one implementation, the system can identify distinct subsets of the aerosol data time series—captured by the sensor unit 120—that correspond to different time periods within the test period.

[0093] In particular, in this implementation, the system can identify a first subset of the aerosol data time series corresponding to a background period—spanning between a first time and a second time—before the dispensing of the tracer test load into the aerosol zone; a second subset of the aerosol data time series corresponding to a dispensing period after the background period and spanning between a second time and a third time—during which the dispenser 110 releases the tracer test load into the aerosol zone; a third subset of the aerosol data time series corresponding to a settling period after the dispensing period and of a target duration (e.g., 1 minute, 5 minutes, 15 minutes)—spanning between a third time and a fourth time; and a fourth subset of the aerosol data time series corresponding to a decay period after the settling period and spanning between a fourth time and a fifth time after the fourth time—corresponding to the removal of the tracer aerosol from the aerosol zone.

[0094] The system can then derive a baseline concentration of aerosol particles present in the aerosol zone during the first test period based on a first subset of the time series of aerosol data captured during the background period, and derive a tracer concentration curve based on a third subset of the time series of aerosol data—captured during the decay period—and the baseline concentrations. In particular, the system can separate the time series of aerosol data recorded during the decay period from the time series of aerosol data recorded during the distribution and / or precipitation periods to minimize noise in the aerosol data due to fluctuations in aerosol concentration during and / or immediately after distribution of the tracer test load as the air in the aerosol zone returns to equilibrium.

[0095] Additionally, the system can utilize the derived baseline concentration of aerosol particles to normalize the concentration of aerosol tracers represented in the time series of aerosol data, thereby taking into account the aerosol particles naturally present within the aerosol zone.

[0096] 7.2 Airflow Values Block S140 of method S100 recites deriving a first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period based on characteristics of the first tracer concentration curve. Generally, the system can leverage characteristics of the tracer concentration curve—derived from the time series aerosol data collected by sensor unit 120 during the decay period—to derive insights regarding the airflow and / or flow of tracer (e.g., particle or aerosol tracer, tracer gas) within the aerosol zone.

[0097] In one implementation, the system can extract the area defined by the tracer concentration curve (area under the curve or "AUC") and derive the volumetric airflow rate of the aerosol zone based on the area and the known volume of the aerosol zone. In particular, in this implementation, the system can perform the process depicted in Figures 3A-3C to derive an airflow value (e.g., air exchange range) representing the removal of air—including particles and / or gases—from the aerosol zone.

[0098] Additionally, in one implementation, the system can derive a composite airflow value for the aerosol zone based on a set of tracer convolution curves derived from time-series aerosol data collected at each sensor unit 120 of a set of sensor units 120 positioned near the dispenser 110 within the aerosol zone.

[0099] For example, during a test period, the system may record a first time series of aerosol data via a first set of sensors 122 integrated into a first sensor unit 120 temporarily positioned at a first unit location within the aerosol zone, wherein the first time series of aerosol data represents the concentration of aerosol particles present in the air at the first unit location; record a second time series of aerosol data via a second set of sensors 122 integrated into a second sensor unit 120 temporarily positioned at a second unit location within the aerosol zone, wherein the second time series of aerosol data represents the concentration of aerosol particles present in the air at the second unit location; and during a spraying period, trigger the release of a first tracer load into the air in the aerosol zone by a sprayer 110 temporarily positioned at a sprayer 110 location within the aerosol zone, wherein the first tracer load includes a test concentration of aerosol tracer particles. The system can then derive a first tracer concentration curve representing the change in concentration of aerosol tracer particles at the first unit location based on the first time series of aerosol data and the test concentration; derive a second tracer concentration curve representing the change in concentration of aerosol tracer particles at the second unit location based on the second time series of aerosol data and the test concentration; and derive a (synthetic) airflow value representing the removal of aerosol particles from the aerosol zone during the first test period based on the first time series of aerosol data, the second time series of aerosol data, and the test concentration.

[0100] 7.3 Tracer Test Consequences Block S150 of method S100 recites interpreting a first outcome of the first tracer test based on a difference between the first airflow value and a target airflow value defined for the aerosol zone.

[0101] In one implementation, the system can access a target airflow value defined for the aerosol zone as calculated based on a set of environmental characteristics of the aerosol zone (e.g., size, occupancy, activity type or level) and interpret a "pass" outcome of the tracer test responsive to the airflow value corresponding to the target airflow value (e.g., matching a value, exceeding a threshold). Alternatively, the system can interpret a "fail" outcome of the tracer test responsive to the airflow value differing from the target airflow value.

[0102] For example, in response to interpreting the first volumetric airflow rate of the aerosol zone for the first tracer test, the system can access a target volumetric airflow rate defined for the aerosol zone based on the aerosol zone's volume, average or current occupancy level, and / or activity type (e.g., exercising, eating, sitting, standing, singing, working) associated with the aerosol zone, etc., and in response to the target volumetric airflow rate exceeding the volumetric airflow rate, interpret a fail outcome for the tracer test. Alternatively, in response to the volumetric airflow rate exceeding and / or matching the target volumetric airflow rate, the system can interpret a pass outcome for the tracer test.

[0103] In another implementation, the system can access a target airflow value defined for the aerosol zone, characterize a difference between the target airflow value and the (observed) airflow value, and interpret a "fail" outcome of the tracer test in response to the difference exceeding a threshold difference. Alternatively, the system can interpret a "pass" outcome of the tracer test in response to the difference being below a threshold difference. Additionally or alternatively, in another implementation, the system can access a target airflow value defined for the aerosol zone, characterize a difference between the target airflow value and the (observed) airflow value, and calculate a outcome score—such as a quantitative or qualitative score—representing the difference between the target airflow value and the (observed) airflow value.

[0104] 7.3.1 Consequence Report In one variation, the system may generate a report of the tracer test and transmit the report to a user (e.g., a manager, operator, administrator) associated with the aerosol zone. In particular, in this variation, the system may generate a first report including the first airflow value and the first outcome, store the first report in a zone profile associated with the aerosol zone, and transmit a copy of the first report to the user (e.g., via the user's mobile device).

[0105] Further, in this variation, the system can attach to the report a first set of setup data representing a setup configuration defined by the dispenser 110 at the dispenser 110 location and the set of sensor units 120 installed at the set of unit locations—including a first sensor unit 120 disposed at the first unit location, a second sensor unit 120 disposed at the second unit location, etc. Thereafter, during preparation for a second tracer test in the aerosol zone, the system can then access the first set of setup data stored in the zone profile, generate a prompt to install the dispenser 110 and the set of sensor units 120—including the first sensor unit 120, the second sensor unit 120, etc.—in the aerosol zone according to the setup configuration, and transmit the prompt to the user. The system can thus promote data reproducibility across tracer tests performed in the aerosol zone by limiting variability in tracer detection due to modifications in the setup configuration.

[0106] 7.4 Air Removal Path In general, the system can utilize airflow values ​​derived for the aerosol zone during tracer testing - such as air exchange ranges (e.g., volumetric air flow rates) - to derive insights into the various air removal paths (or "removal paths") adopted within the aerosol zone.

[0107] In particular, the system may implement the methods and techniques described above to derive airflow values ​​representative of air and / or particle removal from an aerosol zone via a set of removal pathways, such as filtration, ventilation, precipitation, capture, etc. Thus, based on the airflow values—and / or consequences associated with the airflow values ​​(e.g., whether the airflow values ​​correspond to target airflow values ​​defined for the aerosol zone)—the system may characterize the effectiveness of these removal pathways within the aerosol zone and / or suggest a mode of deployment of these removal pathways within the aerosol zone.

[0108] For example, the system may perform a first tracer test for the aerosol zone during a first test period as described above, access a first aerosol removal mode defining a first set of aerosol removal paths—including a first filtration path and a first ventilation path, etc.—employed within the aerosol zone during the first test period, and suspend verification of the first aerosol removal mode in the aerosol zone in response to interpreting a “fail” outcome of the first tracer test—such as in response to deriving an airflow value (e.g., air exchange rate or volumetric flow rate) below a target value. The system may then generate a notification to implement a second aerosol removal mode defining a second set of aerosol removal paths—including a second filtration path and a second ventilation path, etc.—for employment within the aerosol zone during a time period prior to the first test period, and transmit the notification to a user (e.g., an operator, manager, administrator) associated with the aerosol zone.

[0109] The system can then perform a second tracer test for the aerosol zone during a second test period and time period after the first test period—for a target duration—interpret a second airflow value based on the time-series aerosol data collected during the second tracer test, and interpret a passing outcome of the second tracer test in response to the second airflow value exceeding the target airflow value. The system can then access a second aerosol removal mode—defining a second set of aerosol removal paths—to be employed within the aerosol zone during the second test period, and in response to interpreting a passing outcome of the second tracer test, verify the second aerosol removal mode for the aerosol zone. The system can then generate a second notification to maintain implementation of the second aerosol removal mode within the aerosol zone and transmit the notification to a user associated with the aerosol zone.

[0110] In another example, the system may perform a first tracer test for the aerosol zone during a first test period to derive a first airflow value for the aerosol zone, and based on a first outcome—such as the first airflow value being below a target airflow value—identify a first removal path from a set of removal paths configured to drive the first airflow value toward the target airflow value, generate a prompt to implement the first removal path within the aerosol zone, and transmit the prompt to a user associated with the aerosol zone, as described above. Then, during a second test period after the first test period to the target duration, the system may perform a second tracer test for the aerosol zone during the second test period to derive a second airflow value for the aerosol zone, and characterize the effectiveness of the first removal path within the aerosol zone based on a first difference between the first and second airflow values.

[0111] Additionally or alternatively, in one implementation, the system may access a set of environmental controls—including HVAC settings, occupancy level, activity level or type, etc.—for the aerosol zone, such as before, during, and / or after the tracer test is performed within the test period. In this implementation, the system may leverage the results of the tracer test—such as a set of aerosol values ​​derived from time-series aerosol data collected during the tracer test—to characterize the effectiveness of the current environmental controls within the aerosol zone and / or suggest modifications to the current environmental controls to managers, etc., associated with the aerosol zone.

[0112] For example, during the execution of a tracer test within a test period, the system may record a first time series of environmental controls for a first aerosol zone within the facility, such as a first time series of occupancy levels within a first aerosol zone (e.g., number of occupants, occupant density), a first time series of occupancy durations within the first aerosol zone (e.g., duration spent by each occupant within the aerosol zone), a first time series of HVAC data within the first aerosol zone (e.g., temperature, humidity, air filtration rate), and a first time series of intervention data (e.g., window opening or closing, time since last cleaning, type of chemical applied to surfaces). Then, based on the time series aerosol data collected during the execution of the tracer test, the system may interpret a set of airflow values ​​for the aerosol zone—representing the flow and / or movement of aerosols within the aerosol zone during the test period. Based on the set of airflow values, the system can characterize the effectiveness (e.g., percentage, score out of 100, "highly effective," "effective," "ineffective," or "harmful") of the current set of environmental controls—represented by the first time series of environmental controls—implemented within the aerosol zone.

[0113] Further, in the previous example, in response to a particular airflow value among a set of airflow values ​​that does not fall within a threshold deviation of the target metric (e.g., defined for the airflow value), the system may generate a notification including a prompt to modify HVAC settings—such as according to a particular set of HVAC settings—that indicate the particular airflow value and are predicted to drive the particular airflow value toward the target metric.

[0114] In one variation, the system can automatically implement modifications to a set of environmental controls within the aerosol zone based on current airflow values ​​and / or risks—associated with a set of pathogens—within the aerosol zone. In particular, in one example, during execution of a tracer test within a test period, the system can access a first set of HVAC settings currently employed by the HVAC system in the aerosol zone. Then, based on time-series aerosol data collected during execution of the tracer test, the system can interpret a set of airflow values—including a first air exchange rate—for the aerosol zone. In response to the first air exchange rate falling below a threshold air exchange rate defined for the aerosol zone, the system can select a second set of HVAC settings in place of the first set of HVAC settings that is predicted to increase the air exchange rate within the aerosol zone and trigger the HVAC system to adjust the HVAC settings according to the second set of HVAC settings. Additionally, in this example, the system can perform additional tracer tests during a subsequent test period—such as after a threshold duration for receiving confirmation that the HVAC system has implemented the second set of HVAC settings—to verify the increase in the air exchange rate within the aerosol zone. The system may continue to trigger adjustments of HVAC settings within the aerosol zone until the air exchange rate exceeds a threshold air exchange rate defined for the aerosol zone.

[0115] 8. Track airflow values ​​over time In one implementation, the system is capable of tracking changes in airflow values ​​within an aerosol zone over time and predicting causal pathways associated with changes in the derived airflow values ​​of the aerosol zone.

[0116] In particular, in this implementation, the system can predict a first set of airflow values ​​for the aerosol zone during a first test period based on time-series aerosol data collected during the first test period, predict a second set of airflow values ​​for the aerosol zone during a second test period after the first test period based on time-series aerosol data collected during the second test period, characterize a difference between the first set of airflow values ​​and the second set of airflow values, and predict a causal pathway associated with the difference, such as a change in a particular ventilation technique among a set of ventilation techniques employed within the aerosol zone, based on the difference, as described above.

[0117] For example, during a first test period, the system may access a first time series of aerosol data collected by a first sensor unit 120 positioned within the aerosol zone, access a first set of emission parameters corresponding to the dispersion of a first test tracer load during the test period by a dispenser 110 positioned within the aerosol zone, derive a first tracer signal representative of a change in the amount of a first type of tracer in the air detected at the first sensor unit 120 during the first test period based on the first time series of aerosol data and the first set of emission parameters, and predict a first air exchange rate of the first type of aerosolized particles within the aerosol zone during the first test period based on characteristics of the first tracer signal. Then, during a second test period after the first test period, the system can access a second time series of aerosol data collected by the first sensor unit 120, access a second set of emission parameters corresponding to the dispersal of a second test tracer load by the dispenser 110 during the second test period, derive a second tracer signal representative of a change in the amount of the first type of tracer in the air detected at the first sensor unit 120 during the second test period based on the second time series of aerosol data and the second set of emission parameters, and predict a second air exchange rate of the first type of aerosolized particles within the aerosol zone during the second test period based on characteristics of the second tracer signal. The system can then characterize a difference between the first air exchange rate and the second air exchange rate and, in response to the difference exceeding a threshold difference, predict a first causal pathway—such as a change in HVAC settings within the aerosol zone.

[0118] In this implementation, the system can generate notifications indicating detected changes in airflow values ​​(e.g., air exchange rates) within the aerosol zone and transmit these notifications to one or more users associated with the aerosol zone. For example, in the previous example, in response to the difference exceeding the threshold difference, the system can generate notifications indicating the difference between the first air exchange rate and the second air exchange rate—including prompts to verify or modify HVAC settings within the aerosol zone—and transmit the notifications to users associated with the aerosol zone.

[0119] 9. Variation: Tracer gas + aerosol tracer In one variation, block S120 of method S100 recites discharging a first tracer load into ambient air within the aerosol zone via a dispenser 110 temporarily positioned at a target location within the aerosol zone, the first tracer load including a first concentration of aerosol tracer particles and a second concentration of tracer gas. In this variation, block S110 recites recording, during the performance of a first tracer test during a first test period, a first time series of aerosol data - representing the concentration of aerosol particles present in the air at the first unit location during the first test period - via a first sensor (e.g., an aerosol sensor) integrated into a first sensor unit 120 temporarily positioned at a first unit location within the aerosol zone, and recording a second time series of gas data via a second sensor (e.g., a gas sensor) temporarily positioned at a second location within the aerosol zone, the second time series of gas data representing the presence of tracer gas in the air at the second sensor during the test period.

[0120] Generally, in block S110, the sensor unit 120 may access a first sensor (e.g., a particle or aerosol sensor) configured to signal the presence of aerosol particles in the air and a second sensor (e.g., a gas sensor) configured to signal the presence of a tracer gas in the air. The computer system may trigger the sensor unit 120 to begin recording time-series aerosol data via the first sensor and simultaneously trigger the sensor unit 120 to begin recording time-series aerosol data via the second sensor. The sensor unit 120 may then implement the methods and techniques described above to record the time series of aerosol data and the time series of gas data as described above, write the time series of aerosol data and the time series of gas data to local storage of the sensor unit 120, and upload the time series of aerosol data and the time series of gas data to the computer system (e.g., via the sensor communications module 124) at a target logging frequency.

[0121] Furthermore, the system can then utilize this data to derive an aerosol tracer concentration curve representing the time series concentration of aerosol tracer particles in the aerosol zone during the test period, as described above - based on the time series of aerosol data and the first concentration of aerosol particles in the tracer test load - and implement similar methods and techniques to derive a gas tracer concentration curve representing the time series concentration of tracer gas in the aerosol zone during the test period - based on the time series of gas data and the second concentration of tracer gas in the tracer test load.

[0122] The system can then utilize these concentration curves to derive a first airflow value that represents the removal of suspended particles from the aerosol zone based on characteristics of the aerosol concentration curve (e.g., decay rate, AUC, maximum concentration, minimum concentration, duration of the decay period), and a second airflow value that represents the removal of gas from the aerosol zone based on characteristics of the gas concentration curve (e.g., decay rate, AUC, maximum concentration, minimum concentration, duration of the decay period).

[0123] In particular, the system can utilize a first airflow value (e.g., a first volumetric airflow)—representing airborne particle removal from the aerosol zone—to derive insights regarding particle removal pathways (e.g., ventilation, precipitation, capture) associated with particle and / or aerosol removal, and a second airflow value (e.g., a second volumetric airflow)—representing gas removal from the aerosol zone—to derive insights regarding gas removal pathways (e.g., ventilation, precipitation, capture) associated with gas removal from the aerosol zone. The system can thus validate gas removal pathways—such as those related to ventilation and / or outdoor air circulation in an indoor environment—independent of particle removal pathways including ventilation and / or outdoor air circulation, precipitation, filtration, dilution, etc. Furthermore, based on these airflow values—and / or consequences associated with the airflow values ​​(e.g., whether the airflow values ​​correspond to target airflow values ​​defined for the aerosol zone)—the system can characterize the effectiveness of various removal pathways for particles and gases within the aerosol zone and / or suggest modes of deployment of these removal pathways within the aerosol zone.

[0124] In one example, the system can implement the above-described methods and techniques to derive an aerosol airflow value representing particle removal from the aerosol zone via a set of removal paths, such as filtration, ventilation, precipitation, capture, etc., based on characteristics of the aerosol concentration curve; derive a gas airflow value representing gas removal from the aerosol zone via a first removal path, such as a first removal path of the set of removal paths corresponding to ventilation (or "outdoor air"), based on characteristics of the gas concentration curve; access a target aerosol flow value defined for aerosol removal within the aerosol zone; access a target airflow value defined for gas removal within the aerosol zone; access a ventilation rate employed by an HVAC system installed within the aerosol zone during the test period; and derive a minimum ventilation rate based on the ventilation rate and the difference between the gas airflow value and the target gas airflow value. Then, in response to the aerosol airflow value differing from the target aerosol airflow value, the system can derive an estimated airflow value representing particle removal from the aerosol zone during the test period via a first subset of removal paths from the set of removal paths excluding the first removal path, generate a prompt to increase the magnitude of the first removal path employed within the aerosol zone and predicted to drive the aerosol airflow value toward the target aerosol airflow value, and transmit the prompt to a user associated with the aerosol zone.

[0125] The systems and methods described herein may be embodied and / or implemented at least in part as a machine configured to receive a computer-readable medium having computer-readable instructions stored thereon. The instructions may be executed by computer-executable components integrated with the hardware / firmware / software elements of an application, applet, host, server, network, website, communication service, communication interface, user computer or mobile device, wristband, smartphone, or any suitable combination thereof. Other systems and methods of embodiments may be embodied and / or implemented at least in part as a machine configured to receive a computer-readable medium having computer-readable instructions stored thereon. The instructions may be executed by computer-executable components integrated with the types of devices and networks described above. The computer-readable medium may be stored in any suitable computer-readable medium, such as RAM, ROM, flash memory 129, EEPROM, optical device (CD or DVD), hard drive, floppy drive, or any suitable device. The computer-executable component may be a processor, although any suitable dedicated hardware device may (alternatively or additionally) execute the instructions.

[0126] As those skilled in the art will recognize from the foregoing detailed description and from the figures and claims, modifications and variations can be made to the embodiments of the invention without departing from the scope of the invention as defined in the following claims.

Claims

1. During the performance of the first tracer test within the aerosol zone within the first test period, triggering, during a first distribution period, the release of a first tracer load into air within the aerosol zone by a distributor temporarily positioned at a distributor location within the aerosol zone, the first tracer load comprising a test concentration of aerosol tracer particles; and recording a first time series of aerosol data via a set of sensors integrated into a first sensor unit temporarily positioned at a first unit location within the aerosol zone, the first time series of aerosol data representing a concentration of aerosol particles present in the air at the first unit location during the first test period; deriving a first tracer concentration curve representing a change in concentration of aerosol tracer particles at the first unit location during the first test period based on the first time series of aerosol data and the test concentrations; deriving a first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period based on characteristics of the first tracer concentration curve; interpreting a first outcome of the first tracer test based on a difference between the first airflow value and a target airflow value defined for the aerosol zone; A method comprising:

2. recording the first time series of aerosol data during the first test period; recording a first subset of the first time series of aerosol data via the set of sensors during a background period prior to the first dispensing period; and recording a second subset of the first time series of aerosol data via the set of sensors during a decay period after the distribution period. Including, deriving the first tracer concentration curve based on the first time series of aerosol data and the test concentration; deriving a baseline concentration of aerosol particles present within the aerosol zone during the first test period based on the first subset of the first time series of aerosol data; and Deriving the first tracer concentration curve based on the second subset of the first time series of aerosol data and the baseline concentration. Including, The method of claim 1.

3. interpreting the first airflow value based on characteristics of the first tracer concentration curve; extracting the area defined by the first tracer concentration curve; and Deriving the first airflow value comprising a volumetric airflow rate based on the area and the volume of the aerosol zone. Including, interpreting the first outcome of the first tracer test based on the difference between the first airflow value and the target airflow value defined for the aerosol zone; accessing the target airflow value comprising a target volumetric airflow rate defined for the aerosol zone; and interpreting a failure outcome of the first tracer test in response to the target volumetric air flow exceeding the volumetric air flow. Including, The method of claim 2.

4. interpreting the first outcome of the first tracer test based on the difference between the first airflow value and the target airflow value includes interpreting a fail outcome of the first tracer test in response to the first airflow value being less than the target airflow value; accessing a first aerosol removal mode defining a first set of aerosol removal paths employed within the aerosol zone during the first test period; responsive to interpreting the failure outcome of the first tracer test, withholding verification of the first aerosol removal mode within the aerosol zone; during the execution of a second tracer test within the aerosol zone within a second test period after the first test period to a target duration; triggering, during a second dispensing period, the release of a second tracer load into air within the aerosol zone by the dispenser temporarily positioned at the dispenser location, the second tracer load comprising aerosol tracer particles at the test concentration; and recording a second time series of aerosol data via the set of sensors integrated into the first sensor unit temporarily positioned at the first unit location within the aerosol zone, the second time series of aerosol data representing a concentration of aerosol particles present in the air at the first unit location during the second test period; deriving a second tracer concentration curve representing the change in concentration of aerosol tracer particles at the first unit location during the second test period based on the second time series of aerosol data and the test concentrations; deriving a second airflow value representative of the removal of aerosol particles from the aerosol zone during the second test period based on characteristics of the second tracer concentration curve; interpreting a passing outcome of the second tracer test in response to the second airflow value exceeding the target airflow value; accessing a second aerosol removal mode defining a second set of aerosol removal paths employed within the aerosol zone during the second test period; and verifying the second aerosol removal mode of the aerosol zone in response to interpreting the passing outcome of the second tracer test. further comprising: The method of claim 1.

5. deriving the first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period comprises deriving the first air exchange rate representative of the removal of aerosol particles from the aerosol zone during the first test period; interpreting the failure outcome of the first tracer test as a function of the first airflow value being below the target airflow value comprises interpreting the failure outcome of the first tracer test as a function of the first air exchange being below a target air exchange rate defined for the aerosol zone; accessing the first aerosol removal mode defining the first set of aerosol removal paths includes accessing the first aerosol removal mode defining the first set of aerosol removal paths including a first filtration path and a first ventilation path; deriving the second airflow value representative of the removal of aerosol particles from the aerosol zone during the second test period comprises deriving the second air exchange rate representative of the removal of aerosol particles from the aerosol zone during the second test period; interpreting the passing outcome of the second tracer test as a function of the second airflow value exceeding the target airflow value comprises interpreting the passing outcome of the second tracer test as a function of the second air exchange exceeding the target air exchange rate; accessing the second aerosol removal mode defining the second set of aerosol removal paths includes accessing the second aerosol removal mode defining the second set of aerosol removal paths including a second filtration path and a second ventilation path; The method of claim 4.

6. 2. The method of claim 1, wherein releasing the first tracer load comprising the test concentration of aerosol tracer particles comprises releasing the first tracer load comprising the test concentration of aerosol tracer particles comprising particles of an aerosol salt.

7. Based on the first consequence, identifying a first removal path from a set of removal paths configured to drive the first airflow value toward the target airflow value; generating a prompt to perform the first removal path within the aerosol zone; and transmitting the prompt to a user associated with the aerosol zone; during a second test period after the first test period to a target duration; releasing a second tracer load via the dispenser into the air within the aerosol zone during a second dispense period of the first duration, the second tracer load comprising the test concentration of aerosol tracer particles; and recording a second time series of aerosol data via the set of sensors integrated into the first sensor unit, the second time series of aerosol data representing a concentration of aerosol particles detected in the air at the first unit location during the second test period; deriving a second tracer concentration curve representing the change in concentration of aerosol tracer particles within the aerosol zone during the second test period based on the second time series of aerosol data and the test concentrations; interpreting a second airflow value representative of particle removal from the aerosol zone during the second test period based on characteristics of the second tracer concentration curve; characterizing an effectiveness of the first removal path within the aerosol zone based on a first difference between the first airflow value and the second airflow value; The method of claim 1 further comprising:

8. recording, during the first test period, a second time series of aerosol data via a second set of sensors integrated into a second sensor unit temporarily positioned at a second unit location within the aerosol zone, the second time series of aerosol data representing a concentration of aerosol particles present in the air at the second unit location during the first test period; and Deriving a second tracer concentration curve representing the change in concentration of aerosol tracer particles at the second unit location during the first test period based on the second time series of aerosol data and the test concentrations. further comprising deriving the first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period comprises deriving the first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period based on characteristics of the first tracer concentration curve and the second tracer concentration curve. The method of claim 1.

9. generating a first report including the first airflow value, the first outcome, and a first set of setup data representative of a setup configuration defined by the dispenser at the dispenser location, the first sensor unit disposed at the first unit location, and the second sensor unit disposed at the second unit location; storing the first report in a zone profile associated with the aerosol zone; at a first time after the first test period up to a target duration; accessing the first set of setup data stored in the zone profile; generating a prompt to install the dispenser, the first sensor unit, and the second sensor unit within the aerosol zone according to the setup configuration; and transmitting the prompt to a user associated with the aerosol zone; during a second tracer test within a second test period after the first time; releasing a second tracer load via the dispenser into the air within the aerosol zone during a second dispense period of the first duration, the second tracer load comprising aerosol tracer particles at the test concentration; recording a third time series of aerosol data via the set of sensors integrated into the first sensor unit, the third time series of aerosol data representing a concentration of aerosol particles detected in the air at the first unit location during the second test period; and recording a fourth time series of aerosol data via the second set of sensors integrated into the second sensor unit, the fourth time series of aerosol data representing a concentration of aerosol particles detected in the air at the second unit location during the second test period; deriving a third tracer concentration curve representing a change in concentration of aerosol tracer particles at the first unit location during the second test period based on the third time series of aerosol data and the test concentrations; deriving a fourth tracer concentration curve representing a change in concentration of aerosol tracer particles at the second unit location during the second test period based on the fourth time series of aerosol data and the test concentrations; interpreting a second airflow value representative of particle removal from the aerosol zone during the second test period based on characteristics of the third tracer concentration curve and the fourth tracer concentration curve; characterizing a difference between the first airflow value and the second airflow value; The method of claim 8 further comprising:

10. deriving the first airflow value representative of particle removal from the aerosol zone comprises deriving the first airflow value representative of particle removal from the aerosol zone via a set of removal paths; deriving a second airflow value representative of gas removal from the aerosol zone via a first removal path of the set of removal paths, the first removal path including ventilation; accessing a target airflow value defined for gas removal within the aerosol zone; accessing the ventilation rate employed by an HVAC system installed in the aerosol zone during the first test period; deriving a minimum ventilation rate based on the ventilation rate and a difference between the second airflow value and the target airflow value; In response to the first airflow value being different from the target airflow value, estimating a third airflow value representative of particle removal from the aerosol zone during the first test period via a first subset of removal paths of the set of removal paths excluding the first removal path based on a difference between the first airflow value and the second airflow value; generating a prompt to increase a magnitude of the first removal path of the first subset of removal paths employed in the aerosol zone and predicted to drive the first airflow value toward the target airflow value; and transmitting the prompt to a user associated with the aerosol zone. further comprising: The method of claim 1.

11. recording the first time series of aerosol data representative of a concentration of aerosol particles present in the air at the first unit location comprises recording the first time series of aerosol data representative of a concentration of aerosol particles of a first size present in the air at the first unit location; deriving the first tracer concentration curve representing a change in concentration of aerosol tracer particles at the first unit location during the first test period comprises deriving the first tracer concentration curve representing a change in concentration of aerosol tracer particles of the first size at the first unit location during the first test period; recording a second time series of aerosol data via the set of sensors integrated into the first sensor unit temporarily positioned at the first unit location within the aerosol zone, the second time series of aerosol data representing a concentration of aerosol particles of a second size exceeding the first size present in the air at the first unit location during the first test period; Deriving a second tracer concentration curve based on the second time series of aerosol data and the test concentrations, the second tracer concentration curve representing the change in concentration of aerosol tracer particles of the second size at the first unit location during the first test period. further comprising deriving the first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period comprises deriving the first airflow value representative of the removal of aerosol particles from the aerosol zone during the first test period based on characteristics of the first tracer concentration curve and the second tracer concentration curve. The method of claim 1.

12. characterizing the first airflow score based on the difference between the first airflow value and the target airflow value defined for the aerosol zone; accessing a set of environmental characteristics for the aerosol zone, the set including a first size of the aerosol zone and a target occupancy level defined for the aerosol zone; calculating the target airflow value based on the set of environmental characteristics; The method of claim 1 , comprising:

13. triggering the emission of the first tracer load by the dispenser temporarily located at the dispenser location within the aerosol zone comprises triggering the emission of the first tracer load by the dispenser temporarily located at the dispenser location within the aerosol zone; a reservoir containing salt particles in solution; an actuator configured to release a tracer test load from the reservoir and into the aerosol zone, the tracer test load comprising particles of aerosol salt at a first concentration; and a first power module configured to provide power to the actuator; Equipped with recording the first time series of aerosol data via the set of sensors integrated into the first sensor unit temporarily positioned at the first unit location within the aerosol zone comprises recording the first time series of aerosol data via the set of sensors integrated into the first sensor unit temporarily positioned at the first unit location within the aerosol zone; a first set of sensors, a particle sensor configured to signal the presence of aerosol particles in the air at the first unit location; and a gas sensor configured to signal the presence of the tracer gas in the air at the first unit location; a first set of sensors comprising: Sensor communication module, a controller, reading a first time series of signals from the particle sensor in response to a command received by the sensor communications module; reading a second time series of signals from the gas sensor in response to the command; interpreting a time series of amounts of aerosol particles in air flowing through the first unit location based on the first time series of signals; and interpreting the time series of amounts of the tracer gas in the air flowing through the first unit location based on the second time series of signals. a controller configured to: a second power module configured to provide power to the controller and the first set of sensors; Equipped with The method of claim 1.

14. During the performance of the first tracer test within the aerosol zone within the first test period, releasing a first tracer load into ambient air within the aerosol zone via a dispenser temporarily positioned at a target location within the aerosol zone during a first dispensing period, the first tracer load comprising a first concentration of aerosol tracer particles and a second concentration of tracer gas; recording a first time series of aerosol data via a first sensor temporarily positioned at a first unit location within the aerosol zone, the first time series of aerosol data representing the presence of aerosol particles in air at the first sensor during the test period; and recording a second time series of gas data via a second sensor temporarily positioned at a second unit location within the aerosol zone, the second time series of gas data representing the presence of a tracer gas in the air at the second sensor during the test period; deriving an aerosol tracer concentration curve representing a time series concentration of aerosol tracer particles within the aerosol zone during the test period based on the first time series of aerosol data and the first concentration; interpreting a first airflow value representing airborne particle removal from the aerosol zone based on characteristics of the aerosol concentration curve; deriving a gas tracer concentration curve representing a time series of tracer gas concentrations within the aerosol zone during the test period based on the second time series of gas data and the second concentrations; interpreting a second airflow value representing gas removal from the aerosol zone based on characteristics of the gas concentration curve; A method comprising:

15. accessing a first target airflow value representative of airborne particle removal from the aerosol zone; characterizing a first outcome value of the aerosol zone based on a first difference between the first target airflow value and the first airflow value, the first outcome value indicating the effectiveness of a set of particle removal paths implemented within the aerosol zone; accessing a second target airflow value representative of gas removal from the aerosol zone; characterizing a second outcome value for the aerosol zone based on a second difference between the second target airflow value and the second airflow value, the second outcome value indicating the effectiveness of a set of gas removal paths implemented within the aerosol zone; 15. The method of claim 14, further comprising:

16. verifying the effectiveness of the set of particle removal paths implemented within the aerosol zone in response to the first outcome value corresponding to a target outcome value; In response to the second outcome value being different from the target outcome value, flagging said set of gas removal paths for further investigation; generating a notification indicating the second outcome value and including a prompt to modify the set of gas removal paths implemented within the aerosol zone; and transmitting said notification to users associated with said aerosol zone; 16. The method of claim 15, further comprising:

17. interpreting the first airflow values ​​representative of airborne particle removal from the aerosol zone comprises interpreting the first airflow values ​​representative of airborne particle removal from the aerosol zone via a set of removal paths; interpreting the second airflow value representative of gas removal from the aerosol zone includes interpreting the second airflow value representative of gas removal from the aerosol zone via a first removal path of the set of removal paths that includes outdoor air ventilation; characterizing a difference between the first airflow value and the second airflow value; deriving a third airflow value representative of airborne particle removal from the aerosol zone via a set of sub-removal paths of the set of removal paths excluding the first removal path; and calculating a target operating mode for implementation of the subset of removal paths within the aerosol zone based on the third airflow value; further comprising:

15. The method of claim 14.

18. Releasing the first tracer load comprising the first concentration of aerosol tracer particles and the second concentration of the tracer gas comprises: the first concentration of aerosol tracer particles comprising aerosolized salt particles; and The tracer gas at the second concentration includes isopropyl alcohol.

15. The method of claim 14, comprising releasing the first tracer load comprising:

19. a dispenser temporarily installed at a dispenser location within the aerosol zone; A reservoir, a non-volatile tracer in solution, and Volatile tracers in solution a reservoir, an actuator configured to release a tracer test load from the reservoir and into the aerosol zone, the tracer test load including a first concentration of an aerosol tracer and a second concentration of a tracer gas; and a first power module configured to provide power to the actuator; a dispenser comprising: a first sensor unit disposed at a first unit location within the aerosol zone; a first set of sensors, a particle sensor configured to signal the presence of aerosol particles in the air at the first unit location; and a gas sensor configured to signal the presence of the tracer gas in the air at the first unit location; a first set of sensors comprising: Sensor communication module, a controller, reading a first time series of signals from the particle sensor in response to a command received by the sensor communications module; reading a second time series of signals from the gas sensor in response to the command; interpreting a time series of amounts of aerosol particles in air flowing through the first unit location based on the first time series of signals; and interpreting the time series of amounts of the tracer gas in the air flowing through the first unit location based on the second time series of signals. a controller configured to: a second power module configured to provide power to the controller and the first set of sensors; a first sensor unit comprising: A system comprising:

20. further comprising a second sensor unit disposed at a second unit location within the aerosol zone; a second set of sensors, a second particle sensor configured to signal the presence of aerosol particles in the air at the second unit location; and a second gas sensor configured to signal the presence of the tracer gas in the air at the second unit location; a second set of sensors comprising: a second sensor communication module; a second controller, reading a third time series of signals from the second particle sensor in response to a command received by the second sensor communications module; reading a fourth time series of signals from the second gas sensor in response to the command received by the second sensor communication module; interpreting the time series of amounts of aerosol particles in the air flowing through the second unit location based on the third time series of signals; and interpreting the time series of amounts of the tracer gas in the air flowing through the second unit location based on the fourth time series of signals. a second controller configured to: a third power module configured to provide power to the second controller and the second set of sensors. Equipped with the first sensor unit and the second sensor unit cooperate to define a target location for the sensor unit located near the dispenser; 20. The system of claim 19.

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