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:
Aug. 26, 2008
Filed:
May. 13, 2005
Markus Brunner, Breitenbach, CH;
Jürg Dual, Zumikon, CH;
Olivier Elsenhans, Sins, CH;
Frank May, Zürich, CH;
Vuk Siljegovic, Mettmenstetten, CH;
Markus Brunner, Breitenbach, CH;
Jürg Dual, Zumikon, CH;
Olivier Elsenhans, Sins, CH;
Frank May, Zürich, CH;
Vuk Siljegovic, Mettmenstetten, CH;
Roche Diagnostics Operations, Inc., Indianapolis, IN (US);
Abstract
A level sensor apparatus is disclosed for detecting contact of a pipetting needle with a liquid contained in a vessel. The apparatus includes a sensor head made up of a pipetting needle, a needle holder, and an electromechanical transducer. The sensor head also has an associated mechanical resonance frequency. An electrical signal generator is used to generate a driving signal which when applied to the electromechanical transducer causes vibration of the pipetting needle at the resonance frequency. A measurement device is used to measure a parameter of a vibration signal indicative of the mechanical vibration of the pipetting needle when it is driven by the driving signal. An electronic circuit and associated computer software is provided to evaluate variation of the vibration signal with time and thus detect contact of the pipetting needle with a liquid contained in the vessel.