Slope detector

• US 4,199,728 A
• Filed: 08/21/1978
• Issued: 04/22/1980
• Est. Priority Date: 08/21/1978
• Status: Expired due to Term

• Current Assignee: Innovative Medical Systems Corp. (GT Biopharma, Inc.)
• Original Assignee: Innovative Medical Systems Corp. (GT Biopharma, Inc.)
• Inventors: Carpenter, Raymond J.
• Primary Examiner(s): Zazworsky, John
• Application Number:
  US05/935,550
• Time in Patent Office: 610 Days
• Field of Search: 328/114, 328/132, 307/231, 307/232
• US Class Current: 327/14
• CPC Class Codes: G01R 19/12 Measuring rate of change

Abstract

An electronic circuit which tracks an electrical signal to determine if the slope of the signal equals or exceeds a predetermined value in a predetermined time.

Claims

1. Apparatus, to determine if the slope of an input signal equals or exceeds a predetermined value in a predetermined time, comprising:

first means, responsive to said input signal, for generating a first signal which is substantially equal to the input signal;

second means, responsive to the first signal and the input signal for producing a second signal which is equal to the difference between the input signal and the first signal;

third means, responsive to the second signal, for generating a third signal which matches the second signal;

fourth means, responsive to the second signal and the third signal, for producing a fourth signal which is equal to the difference between the second signal and the third signal;

fifth means, responsive to the fourth signal, for producing a fifth signal whenever the fourth signal equals or exceeds a predetermined value; and

sixth means, responsive to the fifth signal, for producing an output signal whenever the fifth signal is present for a predetermined time.

2. Apparatus, to determine if the slope of an input signal equals or exceeds a predetermined value in a predetermined time, comprising:

an analog to digital converter, responsive to the input signal, which produces an output nearly equal to the input signal, during a first time period;

a first differential amplifier which produces a coarsely zeroed signal equal to the difference between the input signal and the output of the analog to digital converter;

a sample and hold circuit for producing an output which matches the output of the first differential amplifier, during a second time period;

a second differential amplifier for producing a finely zeroed output equal to the difference between the output of the first differential amplifier and the output of the sample and hold circuit;

a comparator, responsive to the output of the second differential amplifier and a reference voltage, for producing an output whenever the output of the second differential amplifier equals or exceeds the reference voltage; and

a counter for recording the presence of the comparator output during a third time period and for producing an output signal whenever the comparator output is present during three consecutive third time periods.

3. Apparatus according to claim 2 further including a timing generator for controlling said analog to digital converter, said sample and hold circuit and said counter.