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:
Dec. 28, 1993
Filed:
Apr. 22, 1992
Kenth-Ake-Sune Nilsson, Akersberga, SE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
An implantable medical apparatus for stimulating a heart at a variable stimulation rate dependent on the respiratory rate, tidal volume, heart rate and stroke volume includes a measurement apparatus which measures impedance around the heart, a filter unit which splits the impedance signal into high-frequency and a low-frequency signal portions and two analyzers which respectively evaluate the signal portions and which emit the four parameter values as output signals. The product of respiratory rate times tidal volume is formed in a control apparatus. This product corresponds to respiratory minute volume, and the product of heart rate times stroke volume corresponds to cardiac output. Cardiac output is multiplied by a constant, and respiratory minute volume is subtracted from the product thus formed. The resulting different is equal to zero when blood oxygenation is optimum. The control apparatus controls the stimulation rate on the basis of the magnitude and sign of the difference.