Does the InsiteIG fluorescence technology infringe on any U.S. patents?  BACK TO F.A.Q.s

NO, however it has come to our attention that numerous unfounded rumors concerning this mater have been circulated throughout the marketplace.

We would like to assure you that, InsiteIG is not infringing on US Patent 5,030,420 and the patent holder has not filed suit against InsiteIG or any of our agents. US Patent 5,030,420 is assigned to University of Virginia Alumni Patents Foundation.

US Patent 5,030,420 makes the following single claim in four parts.
     1. An apparatus for measuring oxygen concentration comprising:
         a. A sensor made of luminescent material
         b. A polymer barrier covering the sensor, wherein the polymer is permeable to oxygen
         c. Means for exciting the sensor with a modulated light source to generate luminescence              therein
         d. Means for measuring a phase shift of luminescence generated in the sensor to determine              luminescence lifetime, wherein any quenching related to decrease in lifetime due to the              presence of oxygen are indicative of concentration of oxygen, wherein the barrier comprised              light transmissive cured silicone rubber having tris-(4,7-diphenyl-1,10- phenanthroline)              ruthenium(II) perchlorate immobilized therein as the luminescent material.

Simply put, this patent protects a single type of sensor that must conform to all four of the above characteristics.

Four of the key features which differentiate the Model 10 from the apparatus claim of the patent are:

    1. In regard to ruthenium immobilized in silicone rubber - The Model 10 sensing element consists of ruthenium compound molecules encapsulated in a porous inorganic glass matrix. While there are silicon elements present within the Model 10 sensor, they do not function to immobilize the ruthenium compound, and they are non-light transmissive.
    2. In regard to the lifetime measurement - The Model 10 sensor makes no time resolved measurements of the ruthenium luminescence.
    3. In regard to the modulating light source – The Model 10 sensor has no modulation of the light source for the purpose of phase shift determination, nor is any other method employed for the measurement of luminescence lifetime.
    4. Insite's technology does not measure luminescence at all. Insite measures fluorescence to determine dissolved oxygen levels. While the two methods are similar, there is one key difference. Fluorescence, which is the method used by Insite, is the measurement of the immediate reaction of a material in response to an excitation source. Luminescence is the measurement of energy radiated after the excitation energy source is removed. This method is the one in use by all other manufacturers currently marketing “optical” type DO systems.

We would like to assure you that these differences between the Model 10 and the 5,030,420 Patent, as well as the reasons for non-infringement were explained in writing to the patent holder about 1 1/2 years ago. To date no one has disputed that these differences are in fact real and that these differences mean that the Model 10 does not infringe the 5,030,420 Patent.

Before being misled by idle talk in this matter, our customers or potential customers should consider requesting specific information in writing about any alleged lawsuits.