The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 09, 2008
Filed:
Feb. 03, 2005
Daniel J. Lombardi, Verona, WI (US);
Steven Vos, Madison, WI (US);
Daniel J. Lombardi, Verona, WI (US);
Steven Vos, Madison, WI (US);
Cardinal Health 209, Inc., Madison, WI (US);
Abstract
Amplification of an evoked potential signal is carried out utilizing a high pass filter implemented as an integrator in a feedback loop which drives the DC offset voltage to zero. As a result, the feed-forward amplifier circuit has almost zero volts at its output since the only voltage remaining is the offset voltage of the operational amplifier, which is selected so as to maintain this parameter as low as possible. Because the voltage impressed across the feed-forward amplifier section is close to zero, the gain of this section can be set to zero during the time that the electrical stimulus pulse is present without introducing any additional artifacts and subsequent amplifier stages are not driven into saturation. When the electrical stimulus potential is no longer present or is significantly reduced in amplitude and before the time of receipt of the response signal, the feed-forward amplifier is brought back into the circuit to provide the high gain required to amplify the response signal, which can be measured without interference from saturation of any of the amplifier stages as they recover to baseline.