Laser diode-excited biological particle detection system
First Claim
1. An improved apparatus for identifying the existence of viable biological particles from a particle population containing a mixture of biologically viable and biologically inert particles, the improvement comprising:
- a solid state excitation source wherein said source is a laser diode for emitting a light beam being directed to contact particles of the particle population and having a wavelength above about 320 nm which is operative to excite biomolecules contained therein to produce fluorescence;
a photon counter for measuring the intensity of fluorescence emitted from each contacted particle and producing a signal indicative thereof; and
a microprocessor for comparing each contacted particle'"'"'s fluorescent intensity signal against predetermined criteria and establishing whether that particle is a biologically viable particle or an inert particle.
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Accused Products
Abstract
Apparatus is provided for detection of viable and potentially hazardous biological particles in a population which may be dispersed in fluid flow. The particles are characterized as biological and viable by contacting particles with laser light from a laser diode and then looking for the emission of fluorescence which is typically emitted from bacteria or bacterial spore. Biomolecules which are representative of viability are now known to be excited in range of 320 nm and longer. The resulting apparatus is economical, compact and has low-power requirements enabling portable operation. Preferably, the laser diode is combined with an aerodynamic particle sizer to separate particles for sequential contacts, or with additional timing lasers for establishing particle size.
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Citations
24 Claims
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1. An improved apparatus for identifying the existence of viable biological particles from a particle population containing a mixture of biologically viable and biologically inert particles, the improvement comprising:
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a solid state excitation source wherein said source is a laser diode for emitting a light beam being directed to contact particles of the particle population and having a wavelength above about 320 nm which is operative to excite biomolecules contained therein to produce fluorescence;
a photon counter for measuring the intensity of fluorescence emitted from each contacted particle and producing a signal indicative thereof; and
a microprocessor for comparing each contacted particle'"'"'s fluorescent intensity signal against predetermined criteria and establishing whether that particle is a biologically viable particle or an inert particle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An improved apparatus for identifying the existence of viable biological particles from a particle population containing a mixture of biologically viable and biologically inert particles, the improvement comprising:
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a solid state excitation source wherein said source is a laser diode for emitting a light beam being directed to contact particles of the particle population and having a wavelength above about 320 nm which is operative to excite biomolecules contained therein to produce fluorescence;
means for measuring the intensity of fluorescence emitted from each particle and producing a signal indicative thereof; and
means for comparing each particle'"'"'s fluorescence intensity signal against pre-determined criteria and establishing whether that particle is biologically viable or an inert particle. - View Dependent Claims (18, 19)
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20. A method for identifying the existence of viable biological particles from a particle population containing a mixture of biologically viable and biologically inert particles, the method comprising:
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providing a solid state excitation source wherein said source is a laser diode for emitting a light beam having a wavelength from about 320 nm to 500 nm and a detector for measuring fluorescence emission and producing a signal indicative of the intensity thereof;
contacting the laser beam and particles of the population so as to excite biomolecules contained in a contacted particle to produce fluorescence;
using the detector to measure the intensity of fluorescence from the contacted particle;
comparing each particle'"'"'s fluorescence intensity signal against predetermined criteria and establishing whether that particle is biologically viable or an inert particle. - View Dependent Claims (21, 22, 23, 24)
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Specification