Particle study apparatus including an axial trajectory sensor

Claim 2

A particle study apparatus including the combination of an axial trajectory sensor and a particle analyzing apparatus; said particle analyzing apparatus having a detecting zone through which the particles are caused to pass for producing pulses, and said detecting zone having an axis; the particles, when passing closest to an axial trajectory through the detecting zone, producing desirable particle pulses having amplitudes which are most nearly proportional to the respective sizes of the particles, and also having a certain approximate duration and shape, and the particles when passing through the detecting zone on trajectories displaced from its axis producing other particle pulses having amplitudes which are not necessarily proportional to their respective sizes and having durations and shapes which tend to depart from said certain approximate duration and shape; said axial trajectory sensor being constructed with an input and an output and arranged to respond to said desirable particle pulses in a first manner and to respond to said other particle pulses in a second manner and further comprising: means for measuring the duration of at least a segment of a particle pulse applied to said input at a plurality of different predetermined fractions of the amplitude thereof and deriving a plurality of duration-measuring pulses having the measured durations of the pulse segments at the respective fractions; means for establishing a standard for a desired band of duration values for each of said measured fractional durations; means for comparing each said standard with its related measured fractional duration and for generating a first type of energizing signal if all of the measured fractional durations do not exceed their said standards and a second type of energizing signal if any of the measured fractional durations exceeds its standard; and output means coupled to receive said first and second types of energizing signals for generating, respectively, the first and second manners of response.

Claim 3

A particle study apparatus according to claim 1 which includes means proViding a pair of fluid bodies, an aperture between the bodies with the bodies being insulated from one another electrically except through said aperture, one of said fluid bodies comprising a suspension of particles, means establishing an electric field in the aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, said aperture thereby defining said detection zone, means for detecting the impedance changes and producing said desirable and said other pulses, and means for coupling said detecting means to said sensor input.

Claim 4

A particle study apparatus according to claim 1 which includes means for converting each of said duration-measuring pulses into an electrical time signal pulse the amplitude of which represents the fractional duration, means for establishing an electrical effect for each fraction in the form of a pair of voltage levels, and the band of duration values established by said standard establishing means comprise the voltages between the levels individual to each fraction, and in which said comparing means compares the time signal pulse of each fraction with the pair of voltage levels corresponding to that fraction.

Claim 5

A particle study apparatus according to claim 1 in which said standard establishing means includes at least one memory circuit connected to receive the measured fractional durations for producing at least one corresponding output voltage level which is employed for establishing said standards.

Claim 6

A particle study apparatus according to claim 4 in which there is a different one of said memory circuits for receiving each of said different measured fractional durations, and each said memory circuit is constructed to produce its output voltage level proportional to a predetermined percentile of the measured fractional durations it previously received.

Claim 7

A particle study apparatus according to claim 5 in which said memory circuits are constructed and arranged so that the predetermined percentile is approximately 25 percent.

Claim 8

A particle study apparatus comprising the combination of an axial trajectory sensor and a Coulter type of particle analyzing apparatus in which particles passing through an aperture produce desirable particle pulses whose amplitudes are most nearly proportional to their respective sizes when passing closest to an axial trajectory through the aperture and having thereby a certain approximate duration and shape and in which particles passing through said aperture on trajectories displaced from the axis will produce other particle pulses whose amplitudes are not necessarily proportional to their respective sizes and whose durations and shapes tend to depart from said certain approximate duration and/or shape; said sensor acting to respond to desirable particle pulses and not to respond to said other particle pulses and comprising: input terminal means and output terminal means having a channel for passage of electrical signals between the terminal means with switch means in said channel to control the signals which appear at the output terminal means, the input terminal means adapted to have said desirable and other particle pulses applied thereto, means for measuring the duration of a particle pulse applied to said input terminal means at a plurality of different predetermined fractions of the amplitude of said full particle pulse and deriving a plurality of duration-measuring pulses of constant amplitude and each having the measured duration at the respective fraction, means for converting each of said duration-measuring pulses into a respective time signal pulse whose amplitude is proportional to the duration of the duration-measuring pulse from which it has been converted whereby to derive a plurality of time signal pulses of different amplitudes corresponding in number to the number of fractions, means establishing for each fraction a voltage level corresponding to the maximum amplitude for a time signal pulse rEpresenting maximum duration for a desirable pulse measured at the particular fraction, all time signal pulses of amplitude greater than said voltage level being those corresponding to said other pulses, means comparing each said level with the time signal pulse corresponding to the same fraction individual to the level and producing one type of energizing signal for each time signal pulse that does not exceed its level and a second type of energizing signal for each time signal pulse that exceeds its level, there being as many energizing signal as fractions, and means for applying all of said energizing signals to said switch means in said channel, the switch means being responsive to permit passage to said output pterminal means of an electrical signal derived from a desirable pulse when all of the energizing signals are of the first type, but said switch means being non-responsive and blocking any signals from passage to said output terminal means when any one of said energizing signals is of the second type.

Claim 9

A particle study apparatus comprising the combination of an axial trajectory sensor and a Coulter type of particle analyzing apparatus in which particles passing through an aperture produce desirable particle pulses whose amplitudes are most nearly proportional to their respective sizes when passing closest to an axial trajectory through the aperture and having thereby a certain approximate duration and shape and in which particles passing through said aperture on trajectories displaced from the axis will produce other particle pulses whose amplitudes are not necessarily proportional to their respective sizes and whose durations and shapes tend to depart from said certain approximate duration and/or shape; said sensor acting to respond to desirable particle pulses and not to respond to said other particle pulses and comprising: input terminal means and output terminal means having a channel for passage of electrical signals between the terminal means with switch means in said channel to control the signals which appear at the output terminal means, the input terminal means adapted to have said desirable and other particle pulses applied thereto, means for measuring the duration of a particle pulse applied to said input terminal means at a plurality of different predetermined fractions of the amplitude of said full particle pulse and deriving a plurality of duration-measuring pulses of constant amplitude and each having the measured duration at the respective fraction, means for converting each of said duration-measuring pulses into a respective time signal pulse whose amplitude is proportional to the duration of the duration-measuring pulse from which it has been converted whereby to derive a plurality of time signal pulses of different amplitudes corresponding in number to the number of fractions, means establishing for each fraction a voltage level corresponding to the maximum amplitude for a time signal pulse rEpresenting maximum duration for a desirable pulse measured at the particular fraction, all time signal pulses of amplitude greater than said voltage level being those corresponding to said other pulses, means comparing each said level with the time signal pulse corresponding to the same fraction individual to the level and producing one type of energizing signal for each time signal pulse that does not exceed its level and a second type of energizing signal for each time signal pulse that exceeds its level, there being as many energizing signal as fractions, and means for applying all of said energizing signals to said switch means in said channel, the switch means being responsive to permit passage to said output pterminal means of an electrical signal derived from a desirable pulse when all of the energizing signals are of the first type, but said switch means being non-responsive and blocking any signals from passage to said output terminal means when any one of said energizing signals is of the second type.

Claim 10

A particle study apparatus including the combination of an axial trajectory sensor and a Coulter type of particle analyzing device, said axial trajectory sensor comprising: an input for receiving particle pulses from said analyzing device, means for measuring the duration of each particle pulse at a plurality of different predetermined fractional amplitudes, means for comparing each such measurement with a standard established for each fractional amplitude, and means for rejecting all particle pulses, all of whose measurements at said fractional amplitudes do not meet said standards.

Claim 11

A particle study apparatus including the combination of an axial trajectory sensor and a Coulter type of particle analyzing device, said axial trajectory sensor comprising: an input for receiving particle pulses from said analyzing device, means for measuring the duration of each particle pulse at a plurality of different predetermined fractional amplitudes, means for comparing each such measurement with a standard established for each fractional amplitude, and means for rejecting all particle pulses, all of whose measurements at said fractional amplitudes do not meet said standards.

Claim 12

A particle study apparatus according to claim 8 in which means are provided for establishing said standard on the basis of the measurement of the durations of previous particle pulses made at the particular fractional amplitude.

Claim 13

A particle study apparatus according to claim 8 which includes means providing a pair of fluid bodies, an aperture between the bodies with the bodies being insulated from one another electrically except through said aperture, one of said fluid bodies comprising a suspension of particles, means establishing an electric field in the aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, said aperture thereby defining a detection zone, means for detecting the impedance changes and producing said particle pulses, and means for coupling said detecting means to said sensor input.