Axial trajectory sensor having gating means controlled by pulse duration measuring for electronic particle study apparatus and method

Claim 2

An axial trajectory sensor for use with a Coulter type 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 said aperture and having thereby a certain approximate duration, 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 tend to be greater than said certain approximate duration; said sensor acting to respond to said desirable particle pulses and not to respond to said other pulses and comprising: A. input terminal means and output terminal means having a channel for passage of electrical signals between the terminal means with gate 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, B. 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, i. said portion comprising the extent of particle pulse between one of the first-occuring maximum and minimum slopes on the leading edge of the pulse and ii. extending to a predetermined part of the trailing edge of the pulse, C. means for converting said duration measuring pulse into an electrical quantity whose value is proportional to the time duration of said duration-measuring pulse, D. means for establishing an electrical effect of a standard equivalent to a maximum desired duration distinguishing between quantities produced by desirable and other pulses, E. means comparing said quantity with said standard and providing a first type of energizing signal if the quantity does not exceed the standard and a second type of signal if the quantity does exceed the standard, and F. means for applying one of said energizing signals to the gate means in said channel to permit passage to said output terminal means of only electrical signals derived from desirable particle pulses.

Claim 3

The axial trajectory sensor as claimed in claim 1 in which means are provided to close said gate means irrespective of the application of an energizing signal to open said gatE means in the event that a particle pulse has two points of zero slope.

Claim 4

The axial trajectory sensor as claimed in 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 5

The axial trajectory as claimed in claim 3 in which said locating means comprise a differentiator for differentiating said particle pulse once.

Claim 6

The axial trajectory sensor as claimed in claim 3 in which the predetermined part of the trailing edge at which said portion terminates is the point at which said trailing edge subsides to a predetermined fraction of the amplitude of the particle pulse and said measuring means include means for locating said point.

Claim 7

The axial trajectory sensor as claimed in claim 5 in which said locating means comprise a pulse stretcher and attenuator connected to provide a stretched attenuated signal and means for comparing the attenuated signal with said particle pulse.

Claim 8

The axial trajectory sensor as claimed in claim 6 in which the means for locating the first-occurring minimum slope comprise a differentiator for differentiating said particle pulse once.

Claim 9

The axial trajectory sensor as claimed in 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 10

The axial trajectory sensor as claimed in claim 8 in which said locating means comprise circuitry for differentiating said particle pulse to obtain a second differential thereof.

Claim 11

The axial trajectory sensor as claimed in claim 9 which includes means responsive to said differentiating circuitry to produce a train of signals for each particle pulse which is characteristic of the number of peaks of said particle pulse, and means for responding to the train of signals to close the gate means any time that a train of pulses signifies the presence of a particle pulse having more than one peak.

Claim 12

The axial trajectory sensor as claimed in claim 8 in which the predetermined part of the trailing edge at which said portion terminates is the point of maximum slope thereof and said measuring means include means for locating said point.

Claim 13

The axial trajectory sensor as claimed in claim 11 in which said point locating means and said means for locating the first-occurring maximum slope are the same.

Claim 14

The axial trajectory sensor as claimed in claim 11 in which said point locating means and said means for locating the first-occurring maximum slope are the same and comprise circuitry for differentiating said particle pulse to obtain a second differential thereof.

Claim 15

An axial trajectory sensor for use with a Coulter type 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 said aperture and having thereby a certain approximate duration, 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 tend to be greater than said certain approximate duration; said sensor acting to respond to said desirable particle pulses and not to respond to said other pulses and comprising: A. 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, B. 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, i. 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 ii. extending to a predetermined part of the trailing edge of the pulse, C. 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, D. means for establishing a voltage level representative of the amplitude equivalent to the maximum duration of desirable particle pulses, E. 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, F. gating means provided between the comparing means and the switch means, G. 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, H. means for applying all particle pulses through said channel to said switch means in synchronized relation with said strobing pulse, I. 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 16

An axial trajectory sensor for use with a Coulter type 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 said aperture and having thereby a certain approximate duration, 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 tend to be greater than said certain approximate duration; said sensor acting to respond to said desirable particle pulses and not to respond to said other pulses and comprising: A. 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, B. 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, i. 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 ii. extending to a predetermined part of the trailing edge of the pulse, C. 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, D. means for establishing a voltage level representative of the amplitude equivalent to the maximum duration of desirable particle pulses, E. 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, F. gating means provided between the comparing means and the switch means, G. 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, H. means for applying all particle pulses through said channel to said switch means in synchronized relation with said strobing pulse, I. 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 17

The axial trajectory sensor as claimed in claim 14 in which means are provided to close said gating means irrespective of the application of an energizing signal to open said gating means in the event that a particle pulse has two points of zero slope.

Claim 18

The axial trajectory sensor as claimed in claim 14 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 19

The axial trajectory as claimed in claim 16 in which said last-mentioned means comprise a differentiator for differentiating said particle pulse once.

Claim 20

The axial trajectory sensor as claimed in claim 16 in which the predetermined part of the trailing edge at which said portion terminates is the point at which said trailing edge subsides to a predetermined fraction of the amplitude of the particle pulse and said measuring means include means for locating said point.

Claim 21

The axial trajectory sensor as claimed in claim 18 in which said locating means comprise a pulse stretcher and attenuator connected to provide a stretched attenuated signal and means for comparing the attenuated signal with said particle pulse.

Claim 22

The axial trajectory sensor as claimed in claim 19 in which the means for locating the first-occurring minimum slope comprise a differentiator for differentiating said particle pulse once.

Claim 23

The axial trajectory sensor as claimed in claim 14 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 24

The axial trajectory sensor as claimed in claim 21 in which said locating means comprise circuitry for differentiating said particle pulse to obtain a second differential thereof.

Claim 25

The axial trajectory sensor as claimed in claim 22 which includes means responsive to said differentiating circuitry to produce a train of signals for each particle pulse which is characteristic of the number of peaks of said particle pulse, and means for responding to the train of signalS to close the gate means any time that a train of pulses signifies the presence of a particle pulse having more than one peak.

Claim 26

The axial trajectory sensor as claimed in claim 21 in which the predetermined part of the trailing edge at which said portion terminates is the point of maximum slope thereof and said measuring means include means for locating said point.

Claim 27

The axial trajectory sensor as claimed in claim 24 in which said point locating means and said means for locating the first-occurring maximum slope are the same.

Claim 28

The axial trajectory sensor as claimed in claim 24 in which said point locating means and said means for locating the first-occurring maximum slope are the same and comprise circuitry for differentiating said particle pulse to obtain a second differential thereof.

Claim 29

A sensor for use with a Coulter type particle analyzing apparatus in which particles passing through an aperture produce 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 other pulses and comprising: A. 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 other particle pulses applied thereto, B. gating means for operating said switch means, C. 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 D. a connection from said last means to said gatng 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 30

A sensor for use with a Coulter type particle analyzing apparatus in which particles passing through an aperture produce 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 other pulses and comprising: A. 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 other particle pulses applied thereto, B. gating means for operating said switch means, C. 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 D. a connection from said last means to said gatng 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 31

The sensor as claimed in claim 27 in which said 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.

Claim 34

The method as claimed in claim 29 in which the measuring step includes measuring the duration from the minimum slope of the leading edge.

Claim 35

The method as claimed in claim 29 in which the measuring step includes measuring the duration from the maximum slope of the leading edge.

Claim 36

The method as claimed in claim 29 in which the measuring step includes measuring the duration from the minimum slope of the leading edge to a fractional amplitude on the trailing edge.

Claim 37

The method as claimed in claim 29 in which the measuring step includes measuring the duration from the maximum slope of the leading edge to the maximum slope of the trailing edge.

Claim 38

The method as claimed in claim 29 in which the measuring step includes deriving the first differential of the pulse so that the zero-crossing thereof marks the point of minimum slope of the leading edge.

Claim 39

The method as claimed in claim 33 in which the measuring step includes deriving the second differential of the pulse so that the first and last zero-crossings identify the points of maximum slope on the leading and trailing edges of said pulse.

Claim 40

An axial trajectory sensor for use with a particle study apparatus in which particles pass through a detecting zone having an axis for producing particle pulses, 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 in which particles passing through the detecting zone on trajectories displaced from its axis will produce 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 sensor being constructed with an input and arranged to respond to said desirable particles pulses in a first manner and to respond to said other particles pulses in a second manner and comprising: A. means for measuring the duration of a portion of a particle pulse applied to the sensor input and for deriving a duration-measuring 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; B. means for establishing an electrical standard equivalent to a maximum desired duration for the duration-measuring pulses; C. 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 signal if said standard is exceeded, and D. means coupled to receive said first and second types of signals for generating, respectively, the first and second manners of response.

Claim 41

An axial trajectory sensor for use with a particle study apparatus in which particles pass through a detecting zone having an axis for producing particle pulses, 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 in which particles passing through the detecting zone on trajectories displaced from its axis will produce 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 sensor being constructed with an input and arranged to respond to said desirable particles pulses in a first manner and to respond to said other particles pulses in a second manner and comprising: A. means for measuring the duration of a portion of a particle pulse applied to the sensor input and for deriving a duration-measuring 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; B. means for establishing an electrical standard equivalent to a maximum desired duration for the duration-measuring pulses; C. 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 signal if said standard is exceeded, and D. means coupled to receive said first and second types of signals for generating, respectively, the first and second manners of response.