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Expired Canadian patentCanada

Medical stimulator with stimulation signal characteristics modulated as a function of stimulation signal frequency

CA 1283711 C · Owner: Ioffe, Zosim · Inventors: Ioffe, Zosim; Morawetz, Peter L.

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A transcutaneous electrical nerve stimulation (TENS) apparatus includes first second, and third oscillators. The first oscillator produces a first train of pulses at a main frequency. The second oscillator produces a second train of pulses at a modulation frequency. Output levels of the second train of pulses vary as a function of the modulation frequency. A frequency control simultaneously controls both the main and modulation frequencies. The third oscillator is responsive to the first and second oscillators and produces a third train of pulses at the main frequency. Intensity and frequency of the pulses of the third pulse train are modulated as a function of the output levels of the …

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted April 30, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 30, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledFebruary 6, 1986
GrantedApril 30, 1991
Term endedApril 30, 2008
Patent numberCA 1283711 C
Classification (IPC)A61N1/36

Timeline

Timeline From CIPO dates

19871990199319961999200220052008Application filedFeb 6, 1986Patent grantedApril 30, 1991Term endedApril 30, 2008

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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.