Methods and systems for detecting aerosol particles
Inventors
McLoughlin, Michael • Kliegman, Ross • Cornish, Tim • Berkout, Vadym • Ecelberger, Scott • Arce, Gonzalo • Regan, Kyle
Assignees
Publication Number
US-11996279-B2
Publication Date
2024-05-28
Expiration Date
2040-06-27
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Abstract
Disclosed are systems are methods for identifying the composition of single aerosol particles, particularly that of bioaerosol particles. A continuous timing laser tightly coupled with a pulse ionization laser is used to index aerosol particles, measure particle properties, and trigger the ionization laser to fire when each particle enters the beam of the trigger laser. Ionized fragments and optionally photons produced when each particle is struck by the ionization laser are analyzed using one or more detectors including a TOF-MS detector and an optical detector. Individual single particle spectra are aligned and denoised prior to averaging.
Core Innovation
The invention provides systems and methods for identifying the composition of single aerosol particles, particularly bioaerosol particles, using a tightly coupled arrangement of a continuous timing laser and a pulse ionization laser. The continuous timing laser indexes each particle, measures properties such as size, shape, and fluorescence, and triggers the ionization laser to fire when each particle enters the beam. Ionized fragments and optionally photons produced by the ionization laser are analyzed using detectors, including a time-of-flight mass spectrometry (TOF-MS) detector and optical detectors, to generate unique spectra for each particle.
Current methods for detecting aerosolized biological and chemical agents are limited by slow analysis times due to the need for extensive sample processing steps like culturing, extraction, or matrix coating. Such delays are unacceptable in situations where real-time identification is critical, such as biodefense or point-of-care healthcare. Existing systems either target only specific bacterial analytes, exclude viruses and toxins, or are unable to provide high-confidence results quickly due to the requirement of bulk sample analysis, which leads to variability and reduced specificity.
This invention addresses these problems by enabling real-time, high-accuracy identification of a wide range of aerosol analyte particles, including bacteria, fungi, viruses, and toxins. It employs a system where single aerosol particles can be individually tracked, optically characterized, selectively ionized, and analyzed using fused data from multiple detectors, augmented by advanced data processing methods such as alignment, denoising, and machine learning. The approach overcomes limitations of bulk sample inhomogeneity and long processing times, providing rapid and specific detection without the need for complex organic matrices.
Claims Coverage
The patent discloses two independent claims outlining two main inventive features.
System for single particle aerosol composition identification using indexed optical and mass spectral analysis
A system comprising: - An aerosol beam generator producing a beam of single particles. - A single guide tube downstream of the aerosol beam generator, guiding particles along the longitudinal axis. - A continuous laser generator creating a single continuous laser beam that indexes each particle as it exits the guide tube, optically characterizes particle properties (size, shape, fluorescence), and selects which particles to ionize. - A pulse ionization laser generator producing UV and/or IR pulses as a pulse ionization laser beam, triggered when a selected indexed particle enters the continuous laser beam, with the two beams arranged to overlap. - A TOFMS detector analyzing ionized fragments generated by the pulse ionization laser, producing unique mass spectral data per particle. - A data analysis system compiling optical and mass spectral data using data fusion, and comparing the compiled data with a training knowledge base to predict particle composition.
Method for identifying the composition of aerosol particles via indexed detection, selective ionization, and fused analysis
A method comprising: 1. Generating an aerosol particle beam of single particles and guiding them through a single guide tube. 2. Using a single continuous laser beam to index each particle after exiting the guide tube, optically characterizing properties (size, shape, fluorescence), and selecting which ones to ionize. 3. Triggering a pulse ionization laser generator to produce pulse ionization laser beam (with UV/IR pulses) as each selected particle enters the continuous laser beam, with beams overlapping. 4. Analyzing ionized fragments produced in the ionization region by TOFMS to generate unique mass spectral data for each indexed particle. 5. Compiling optical and mass spectral data using data fusion, and comparing with a knowledge base to predict particle composition.
The inventive features cover both the system architecture and the method steps for real-time, single-particle aerosol analysis, integrating optical indexing and characterization with triggered ionization and fused data analysis.
Stated Advantages
Allows real-time identification of aerosol analyte particles, including bacteria, fungi, viruses, and toxins, with high accuracy, sensitivity, and specificity.
Eliminates the need for extensive sample processing steps, such as culturing, extraction, or matrix coating, as required in conventional MALDI mass spectrometry.
Combines optical and mass spectral data for each individual particle using data fusion, improving prediction and identification capability.
Enables selective analysis by triggering ionization only when specific particle properties meet predetermined thresholds, reducing superfluous data and improving data management.
Increases signal to noise ratio and data quality through the use of guide tubes, tightly coupled laser beams, advanced triggering, and multistage ion extraction.
Improves accuracy, sensitivity, and specificity further by using machine learning and advanced data processing, including spectrum alignment and denoising.
Documented Applications
Detection and identification of aerosolized biological and chemical threat agents for biodefense applications.
Real-time monitoring of air within structures like office buildings, airports, mass transit facilities, and inhabited areas to provide timely information about contaminants.
Analyzing the headspace in fermenters for possible contaminants.
Determining the speciation of microbes in ambient air of food and healthcare facilities.
Capturing and analyzing exhaled breath particles for medical, diagnostic, or point-of-care healthcare applications.
Analysis of liquid samples that are aerosolized, enabling detection of viruses and toxins in addition to bacteria.
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