Method and apparatus for generating a statistical basis

A system for measuring events and characterizing datum as a function of a specific event duration relative to an updated statistical threshold of previous event duration, comprising:

• an up-down counter, an up-counter, a digital comparator connected to both the up-counter and the up-down counter, photosensor means for generating a logic level signal in response to and throughout the occurrence of an event, a first flip-flop responsive to the leading edge of the logic level signal from the photosensor means, oscillator means, a first AND gate receiving the output from the first flip-flop and concurrently receiving a frequency from the oscillator means to produce a digital output signal for such time as the first flip-flop is activated, the digital signal output from the first AND gate being in communication with the input of the up-counter, the logic level from the photosensor means also being applied to a NOR gate input, the output from the digital comparator providing a second NOR gate input, and the output of the NOR gate being applied to a second AND gate input in conjunction with a signal from the oscillator means and the output from the first flip-flop with the output frequency from the second AND gate being connected to the down-count input of the up-down counter, a third AND gate, the logic level signal from the photosensor means also being gated through the third AND gate in conjunction with the response signal from the digital comparator and a frequency from the oscillator means with the output from the third AND gate being connected to the up-count input of the up-down counter, the logic level signal from the photosensor means further being connected through an inverter to a second flip-flop which is thereby responsive to the trailing edge of the logic level signal, and a third flip-flop activatable by the response from the digital comparator, the output from the second flip-flop, and the third flip-flop being gated through a fourth AND gate to a one-shop reset, whereby a photosensor logic level signal initially activates and latches by means of the first flip-flop the digital output signal which is provided to the up-counter and thus to an input of the digital comparator, but, upon termination of the logic level input signal prior to response from the digital comparator, and a resulting lack of joint denial at the NOR gate, activates the second AND gate thereby providing a frequency to the down-count input of the up-down counter, and thus an indication of a "short" event or, alternatively, if the response from the digital comparator occurs prior to termination of logic level signal, coincidence of the logic level signal and the response from the digital comparator at the third AND gate provides an up-count frequency to the up-count input of the up-down counter, and thus an indication of a "long" event, and, finally, activation of the second flip-flop by the trailing edge of the logic level signal in conjunction with activation of the third flip-flop by the response from the digital comparator gates a signal through the fourthe AND gate to the one-shop reset thereby resetting the first, second and third flip-flops and the up-counter.

A method for generating a currently updated statistical threshold, comprising:

• generating a digital input signal at least proportional to a signal measuring the magnitude of a parameter of an event, latching the digital input signal, up-counting an up-counter in response to the digital signal, continually comparing the count in the up-counter to an existing count in an up-down storing processed counts from previous events, generating a response upon equivalency of the count in the up-counter and the count in the up-down counter, generating a down-count frequency and down-counting the up-down counter upon termination of the signal measuring the event parameter magnitude prior to the equivalency response, and continuing the down-count frequency until the equivalency response is generated, generating an up-count frequency and applying the frequency to the up-count input of the up-down counter upon generation of the equivalency response prior to termination of the signal measuring the event parameter magnitude, and, upon both termination of the signal measuring the event parameter magnitude and generation of the equivalency response, terminating the digital input signal and resetting the up-counter to zero, whereby the currently updated statistical threshold of the magnitude of previous event parameters is stored in the up-down counter and the magnitude of a parameter of a current event can be compared to and characterized as being greater than or less than the threshold, and the threshold is updated appropriately to reflect the current event.