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 thereby having a certain approximate duration, 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 which tend to be longer than said certain approximate duration; 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 predetermined portion of a particle pulse applied to the input of said sensor at some predetermined fraction of the amplitude thereof and deriving a durationmeasuring pulse having the measured duration, said pulse portion comprising the extent of the particle pulse lying between one of the first-occurring maximum and minimum slopes on the leading edge of the pulse and extending to a predetermined part of the trailing edge of the pulse, means for establishing an electrical standard equivalent to a maximum desired duration for the duration-measuring pulses, means for comparing each said duration-measuring pulse with said standard and for providing a first type of energizing signal if said standard is not exceeded and a second type of energyzing signal if said standard is exceeded, 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 in which the portion comprising the extent of the particle pulse commences at the first-occurring minimum slope of the leading edge and said measuring means include means for locating said first-occurring minimum slope.

Claim 4

A particle study apparatus according to claim 2 in which said locating means comprise a differentiator for differentiating said particle pulse once.

Claim 5

A particle study apparatus according to claim 1 in which the portion comprising the extent of the particle pulse commences at the first-occurring maximum slope of the leading edge and said measuring means include means for locating said first-occurring maximum slope.

Claim 6

A particle study apparatus according to claim 4 in which said locating means comprise circuitry for differentiating said particle pulse to obtain a second differential thereof.

Claim 7

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 one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of said particles, said aperture thereby defining said detecting zone, means for detecting the impedance changes and producing said desirable and said other particle pulses, and means for coupling said detecting means to said sensor input.

Claim 8

A particle study apparatus according to claim 1 in which said output means includes a gate and said first type of energizing signal opens said gate, and in which circuit means are provided to close said gate irrespective of the application of an energizing signal to open said gate in the event that a particle pulse has two points of zero slope.

Claim 9

A particle study apparatus comprising the combination of an axial trajectory sensor and a Coulter type of particle analyzing apparatus said Coulter type of particle analyzing apparatus including means providing a pair of fluid bodies, an aperture between the bodies and the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means esTablishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, means for detecting the impedance changes and producing said desirable and undesirable particle pulses, and means for coupling said detecting means to an input terminal means of said axial trajectory sensor; particles passing through said aperture producing desirable particle pulses whose amplitudes are most nearly proportional to their respective sizes when passing closest to an axial trajectory through said aperture and having thereby a certain approximate duration, and 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 tend to be greater than said certain approximate duration; said sensor constructed and arranged to respond to said desirable particle pulses and not to respond to said other 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 portion of a particle pulse applied to said input terminal means and deriving a duration-measuring pulse of constant amplitude and having the measured duration, said portion comprising the extent of the particle pulse between one of the first-occurring maximum and minimum slopes on the leading edge of the pulse and extending to a predetermined part of the trailing edge of the pulse, means for converting said duration-measuring pulse into an electrical time signal pulse whose amplitude is proportional to the duration of said duration-measuring pulse, means for establishing a voltage level representative of the amplitude equivalent to the maximum duration of desirable particle pulses, means comparing the amplitude of said electrical time signal with said voltage level and providing a first type of energizing signal if said amplitude does not exceed said level and a second type of energizing signal if the amplitude exceeds said level, gating means provided between the comparing means and the switch means, strobing pulse producing means connected with said switch means and coupled with said duration-measuring means to produce a strobing pulse at said gating means in timed relation to a particle pulse applied to said input terminal means, means for applying all particle pulses through said channel to said switch means in synchronized relation with said strobbing pulse, means for applying said energizing signals to said gating means, said gating means being constructed to pass said strobing pulse to operate said switch means to signal-passing condition only when said first type of energizing signal is applied to said gating means, whereby said switch means will be activated to pass particle pulses whose duration is less than said maximum duration.

Claim 10

A particle study apparatus comprising the combination of an axial trajectory sensor and a Coulter type of particle analyzing apparatus said Coulter type of particle analyzing apparatus including means providing a pair of fluid bodies, an aperture between the bodies and the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means esTablishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, means for detecting the impedance changes and producing said desirable and undesirable particle pulses, and means for coupling said detecting means to an input terminal means of said axial trajectory sensor; particles passing through said aperture producing desirable particle pulses whose amplitudes are most nearly proportional to their respective sizes when passing closest to an axial trajectory through said aperture and having thereby a certain approximate duration, and 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 tend to be greater than said certain approximate duration; said sensor constructed and arranged to respond to said desirable particle pulses and not to respond to said other 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 portion of a particle pulse applied to said input terminal means and deriving a duration-measuring pulse of constant amplitude and having the measured duration, said portion comprising the extent of the particle pulse between one of the first-occurring maximum and minimum slopes on the leading edge of the pulse and extending to a predetermined part of the trailing edge of the pulse, means for converting said duration-measuring pulse into an electrical time signal pulse whose amplitude is proportional to the duration of said duration-measuring pulse, means for establishing a voltage level representative of the amplitude equivalent to the maximum duration of desirable particle pulses, means comparing the amplitude of said electrical time signal with said voltage level and providing a first type of energizing signal if said amplitude does not exceed said level and a second type of energizing signal if the amplitude exceeds said level, gating means provided between the comparing means and the switch means, strobing pulse producing means connected with said switch means and coupled with said duration-measuring means to produce a strobing pulse at said gating means in timed relation to a particle pulse applied to said input terminal means, means for applying all particle pulses through said channel to said switch means in synchronized relation with said strobbing pulse, means for applying said energizing signals to said gating means, said gating means being constructed to pass said strobing pulse to operate said switch means to signal-passing condition only when said first type of energizing signal is applied to said gating means, whereby said switch means will be activated to pass particle pulses whose duration is less than said maximum duration.

Claim 11

A particle study apparatus comprising the combination of sensor and a Coulter type of particle analyzing apparatus said Coulter type of particle analyzing apparatus including means providing a pair of fluid bodies, an aperture between the bodies and the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, means for detecting the impedance changes and producing said desirable and undesirable particle pulses, and means for coupling said detecting means to an input terminal means of said sensor; particles passing through said aperture producing desirablE pulses each having a single peak and whose amplitudes are most nearly proportional to their respective sizes and undesirable pulses each having multiple peaks and whose amplitudes are not necessarily proportional to their respective sizes; said sensor acting to respond to said desirable particle pulses and not to respond to the undesirable 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 the channel to control the signals which appear at the output terminal means, the input terminal means adapted to have the desirable and undesirable particle pulses applied thereto, gating means for operating said switch means, means connected with said input terminal means for counting the number of peaks in any incoming particle pulse and producing a first type of energizing signal if there is one peak and a second type of signal if there is more than one peak in said pulse, and a connection from said peak counting means to said gating means for applying said energizing signals thereto, the gating means being responsive to said first type of energizing signal to operate said switch means to pass the pulse to said output terminal means and responsive to said second type of energizing signal to render said switch means inoperative.

Claim 12

A particle study apparatus comprising the combination of sensor and a Coulter type of particle analyzing apparatus said Coulter type of particle analyzing apparatus including means providing a pair of fluid bodies, an aperture between the bodies and the bodies being insulated one from the other except through said aperture, one of the fluid bodies comprising a sample suspension of particles, means establishing an electric field in said aperture, means for flowing the sample suspension in the aperture to produce impedance changes in the aperture caused by the passage of particles, means for detecting the impedance changes and producing said desirable and undesirable particle pulses, and means for coupling said detecting means to an input terminal means of said sensor; particles passing through said aperture producing desirablE pulses each having a single peak and whose amplitudes are most nearly proportional to their respective sizes and undesirable pulses each having multiple peaks and whose amplitudes are not necessarily proportional to their respective sizes; said sensor acting to respond to said desirable particle pulses and not to respond to the undesirable 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 the channel to control the signals which appear at the output terminal means, the input terminal means adapted to have the desirable and undesirable particle pulses applied thereto, gating means for operating said switch means, means connected with said input terminal means for counting the number of peaks in any incoming particle pulse and producing a first type of energizing signal if there is one peak and a second type of signal if there is more than one peak in said pulse, and a connection from said peak counting means to said gating means for applying said energizing signals thereto, the gating means being responsive to said first type of energizing signal to operate said switch means to pass the pulse to said output terminal means and responsive to said second type of energizing signal to render said switch means inoperative.

Claim 13

A particle study apparatus according to claim 9 in which the peak counting means include a circuit for obtaining a second differential of said incoming pulse, a circuit for counting the number of zero crossings of the base line of said second differential and producing a train of pulses characteristic of said number, and a counter responsive to said train of pulses and producing said first type of energizing signal only when said train of pulses comprises two pulses, and said second type of energizing signal when said train contains more than two pulses.