Pulse analyzing apparatus

Claim 2

A particle analyzing system responsive to the size of particles comprising: a transducer having an ambit through which each particle passes to produce a size-amplitude related pulse of random shape, the amplitude of such a related pulse being especially significant at the time when the particle passes through the center of said ambit, pulse center finding apparatus including means responsive to said random shaped pulses for generating a related signal having an amplitude equal to the amplitude occurring only at the center of each said random shaped pulse and regardless of pulse peaks occurring either before or after said center, said center finding apparatus constructed and arranged to operate independent of pulse amplitude peaks, and signal classification circuits coupled to receive each said signal.

Claim 3

A particle analyzing system responsive to the passage of particles in suspension, said system having a transducer through which said particles pass to produce electrical pulses which are of random amplitudes, commonly asymmetric about their peaks, but are proportional, at least at their center, to the size of the respective particles producing the same and of a duration equal to the duration of passage of the respective particles through said transducer, said system further having pulse classification circuits for making studies of said particles; and a pulse center finding apparatus for improving the accuracy of said pulse classification circuits in such studies, said center finding apparatus including means interposed between said transucer and pulse classification circuits for locating the center of each pulse independent of the pulse shape, and means responsive to said center locating means for producing a signal whose amplitude is substantially equal to the amplitude occurring only the center of said random amplitude pulses and regardless of pulse peaks occurring either before or after said center, the center finding apparatus being connected to apply all of the signals to the classification circuits independent of said pulses.

Claim 4

A particle analyzing system responsive to the passage of particles in suspension, said system having a transducer through which said particles pass to produce electrical pulses which are of random amplitudes, commonly asymmetric about their peaks, but are proportional, at least at their center, to the size of the respective particles producing the same and of a duration equal to the duration of passage of the respective particles through said transducer, said system further having pulse classification circuits for making studies of said particles; and a pulse center finding apparatus for improving the accuracy of said pulse classification circuits in such studies, said center finding apparatus including means interposed between said transucer and pulse classification circuits for locating the center of each pulse independent of the pulse shape, and means responsive to said center locating means for producing a signal whose amplitude is substantially equal to the amplitude occurring only the center of said random amplitude pulses and regardless of pulse peaks occurring either before or after said center, the center finding apparatus being connected to apply all of the signals to the classification circuits independent of said pulses.

Claim 5

An improved pulse analyzing apparatus for finding pulse amplitude at the center of a pulse, particularly a pulse which is asymmetric about its peak, comprising: comparing circuitry for receiving said pulse, generating its own integral, and comparing said integral and pulse, said integral passing through the center amplitude of said pulse at the time center of the pulse independent of the location of the pulse peak and particularly when the time center is other than at the peak of the pulse, a switch, elements coupled between said comparing circuitry and said switch for operating said switch for a fixed duration commencing at the time said pulse and integral obtain said center amplitude in said comparing circuitry, a signal having said center amplitude being connected to said switch, and said switch enabled to pass said signal only for the said fixed duration, the output of said switch comprising the output from said center finding apparatus.

Claim 6

An improved pulse analyzing apparatus for finding pulse amplitude at the center of a pulse, particularly a pulse which is asymmetric about its peak, comprising: comparing circuitry for receiving said pulse, generating its own integral, and comparing said integral and pulse, said integral passing through the center amplitude of said pulse at the time center of the pulse independent of the location of the pulse peak and particularly when the time center is other than at the peak of the pulse, a switch, elements coupled between said comparing circuitry and said switch for operating said switch for a fixed duration commencing at the time said pulse and integral obtain said center amplitude in said comparing circuitry, a signal having said center amplitude being connected to said switch, and said switch enabled to pass said signal only for the said fixed duration, the output of said switch comprising the output from said center finding apparatus.

Claim 7

The apparatus as defined in claim 3 in which said switch operating elements are coupled back to said comparing circuitry to reset said comparing circuitry upon operation of said operating elements.

Claim 8

Apparatus as defined in claim 3 in which said signal is said pulse.

Claim 9

Apparatus as defined in claim 3 in which said signal is derived from said integral.

Claim 10

The apparatus as defined in claim 3 in which each said pulse is derived from an instrument having an electrical path of finite length which is coupled to said comparing circuitry such that the longitudinal center of said path corresponds to the center of said pulse.

Claim 11

The apparatus as defined in claim 3 in which there is a low threshold circuit coupled to directly receive each said pulse and to produce a response to each pulse exceeding a given threshold level, and a second switch coupled between said low threshold circuit and said comparing circuitry, said second switch coupling to said comparing circuitry only those pulses which produce a response by said low threshold circuit and inhibiting receipt of all other of said pulses.

Claim 12

An improved pulse analyzing apparatus for finding pulse amplitude at the center of a pulse comprising: comparing circuitry for receiving said pulse, generating its own integral, and comparing said integral and pulse, said integral passing through the center amplitude of said pulse at the time center of the pulse, a switch, elements coupled between said comparing circuitry and said switch for operating said switch for a fixed duration commencing at the time said pulse and integral obtain said center amplitude in said comparing circuitry, a signal having said center amplitude being connected to said switch, and said switch enabled to pass said signal only for the said fixed duration, the output of said switch comprising the output from said center finding apparatus, said comparing circuitry including: an integrator, each pulse being adapted to energize the integrator to produce a voltage output signal; scaling means connected to the integrator to adjust the voltage output signal to be equal to the voltage of the pulse energizing the integrator at the time center of the pulse; and an arrangement for detecting the voltage difference between the pulse and voltage output signal and responding to a minimum of difference to provide a gate signal; said gate signal being connected to said operating elements.

Claim 13

An improved pulse analyzing apparatus for finding pulse amplitude at the center of a pulse comprising: comparing circuitry for receiving said pulse, generating its own integral, and comparing said integral and pulse, said integral passing through the center amplitude of said pulse at the time center of the pulse, a switch, elements coupled between said comparing circuitry and said switch for operating said switch for a fixed duration commencing at the time said pulse and integral obtain said center amplitude in said comparing circuitry, a signal having said center amplitude being connected to said switch, and said switch enabled to pass said signal only for the said fixed duration, the output of said switch comprising the output from said center finding apparatus, said comparing circuitry including: an integrator, each pulse being adapted to energize the integrator to produce a voltage output signal; scaling means connected to the integrator to adjust the voltage output signal to be equal to the voltage of the pulse energizing the integrator at the time center of the pulse; and an arrangement for detecting the voltage difference between the pulse and voltage output signal and responding to a minimum of difference to provide a gate signal; said gate signal being connected to said operating elements.

Claim 14

The apparatus as defined in claim 9 in which said voltage detecting arrangement includes a differential amplifier and said operating elements include a minimum signal sensor which is coupled to receive said gate signal and produces a response when said gate signal has a substantially minimum value.

Claim 15

The apparatus as defined in claim 10 in which said operating elements further include a multivibrator coupled between said minimum signal sensor and said switch, said multivibrator producing a switch enabling signal of said fixed duration.

Claim 16

The apparatus as defined in claim 11 in which the trailing edge of the switch enabling signal from said multivibrator is coupled back to said integrator for its resetting.

Claim 17

The apparatus as defined in claim 11 in which there is a low threshold circuit coupled to directly receive each said pulse and to produce a response to each pulse exceeding a given threshold level, and a second switch coupled between said low threshold circuit and said comparing circuitry, said second switch coupling to said comparing circuitry only those pulses which produce a response by said low threshold circuit and inhibiting receipt of all other of said pulses.

Claim 18

The apparatus as defined in claim 13 in which there is a third switch coupled between said differential amplifier and said minimum signal sensor, said third switch being enabled by the response of said low threshold circuit for the duration of such response which is coupled to an input of said third switch.

Claim 19

The apparatus as defined in claim 14 in which there is a bistable device interposed between said low threshold circuit and said second switch such that said second switch is closed only by the leading edge of the response from said low threshold circuit.

Claim 20

The apparatus as defined in claim 15 in which the switch enabling signal from said multivibrator is coupled back to said integrator and said bistable device for their resetting.

Claim 21

The apparatus as defined in claim 16 in which each said pulse is derived from an instrument having an electrical path of finite length which is coupled to said comparing circuitry such that the center of said path corresponds to the center of said pulse.

Claim 22

The apparatus as defined in claim 15 in which the response from said minimum signal sensor is coupled back to said bistable device for its resetting.

Claim 23

The apparatus as defined in claim 18 in which each said pulse is derived from an instrument having an electrical path of finite length which is coupled to said comparing circuitry such that the time based center of said path Corresponds to the center of said pulse, each said pulse is elicited by a liquid suspended particle which passes into the ambit of said instrument for a duration equal to that of said pulse, and in which said instrument forms the input portion of a particle analyzing and sizing system and in which said system further comprises pulse classification structure coupled to the output of said center finding apparatus.

Claim 24

A particle analyzing system responsive to the passage of particles in suspension, said system having a transducer through which said particles pass to produce electrical pulses proportional, at least at their center, to the size of the respective particles producing the same and a duration equal to the duration of passage of the respective particles through said transducer, said system further having pulse classification circuits for making studies of said particles; and a pulse center finding apparatus for improving the accuracy of said pulse classification circuits in such studies, said center finding apparatus interposed between said transducer and pulse classification circuits for locating the center of each pulse and, in lieu of each pulse, producing in turn a signal whose amplitude is substantially equal to the amplitude of the pulse in the center thereof and of a fixed duration, the center finding apparatus being connected to apply all of the signals to the classification circuits to the exclusion of said pulses, the center finding apparatus comprising: an integrator coupled to receive pulses from said transducer, a scale factor adjustor coupled to the output of said integrator so that its voltage output is equal to the voltage of the pulse when the particle producing the pulse is in the center of its passage through said transducer, a differential amplifier having the transducer and the integrator connected to the inputs thereof, a minimum signal sensor circuit coupled to the output of the differential amplifier, a multivibrator connected to the sensor circuit and adapted to produce a switching signal of said fixed time duration when the sensor circuit detects a minimum signal, and a switch having said multivibrator and said scale factor adjustor connected thereto, the output of said switch comprising the output of said center finding apparatus.

Claim 25

A particle analyzing system responsive to the passage of particles in suspension, said system having a transducer through which said particles pass to produce electrical pulses proportional, at least at their center, to the size of the respective particles producing the same and a duration equal to the duration of passage of the respective particles through said transducer, said system further having pulse classification circuits for making studies of said particles; and a pulse center finding apparatus for improving the accuracy of said pulse classification circuits in such studies, said center finding apparatus interposed between said transducer and pulse classification circuits for locating the center of each pulse and, in lieu of each pulse, producing in turn a signal whose amplitude is substantially equal to the amplitude of the pulse in the center thereof and of a fixed duration, the center finding apparatus being connected to apply all of the signals to the classification circuits to the exclusion of said pulses, the center finding apparatus comprising: an integrator coupled to receive pulses from said transducer, a scale factor adjustor coupled to the output of said integrator so that its voltage output is equal to the voltage of the pulse when the particle producing the pulse is in the center of its passage through said transducer, a differential amplifier having the transducer and the integrator connected to the inputs thereof, a minimum signal sensor circuit coupled to the output of the differential amplifier, a multivibrator connected to the sensor circuit and adapted to produce a switching signal of said fixed time duration when the sensor circuit detects a minimum signal, and a switch having said multivibrator and said scale factor adjustor connected thereto, the output of said switch comprising the output of said center finding apparatus.

Claim 26

The system as defined in claim 20 in which there is a low threshold circuit connected to the transducer and responsive only to pulses exceeding a given threshold level to produce a response signal, a second switch between the transducer and the integrator, and a control element connecting the response signal to said second signal to permit passage of a pulse from the transducer to the integrator only when said pulse has exceeded said threshold level.

Claim 27

The system as defined in claim 21 in which there is a third switch coupled between said differential amplifier and said minimum signal sensor, said third switch being enabled by the response of said low threshold circuit for the duration of such response which is coupled to an input of said third switch, and a reset path from said minimum signal sensor to said control element.