Patent rights give inventors the ability to stop others from using their invention, which is why patent laws require inventors to describe their invention in a clear and concise manner. Inventors typically spend a lot of time, money, and effort in developing and patenting their inventions, and they should have the right to prevent others from creating similar products or using similar processes that essentially copy their invention but with minor differences. Patent infringement can take different forms, including direct copying of a granted patent or indirect infringement related to functionality and structure. This is where the “Doctrine of Equivalence” becomes relevant. The Doctrine of Equivalence, also known as Triple Identity test to determine whether a product or process infringes on a patented invention. The triple identity elements are :
-Same function – same functions as patented invention
-Same way – performs the function same way as patented invention
-Same result – produce the same result as patented invention
If all three elements are present in the accused product or process, then it is considered equivalent to the patented invention. So basically it restricts competitors from making minor changes to a patented invention in an attempt to avoid infringement.
Definition and Purpose of the Doctrine of Equivalence
The doctrine of equivalence is a legal principle used in patent law to determine if a product or process that does not infringe on a patent claim is still considered equivalent to the claimed invention and therefore infringes on the patent. The doctrine allows for patent infringement to be found even if the infringing product or process does not entirely meet the language of the patented claim but still achieves substantially the same result in the same way as that of the claimed invention unless limited by prosecution history estoppel. Let’s say there is a patent for a device that is used for securing bicycle follows as:
Patent claim:
A device for securing a bicycle to a fixed object comprising a U-shaped lock with a locking mechanism that engages with a locking bar. The device is made of hard steel and is designed to resist cutting and drilling.
Infringing/ Accused device:
A device for securing a bicycle to a fixed object, comprising a D-shaped lock with a locking mechanism that engages with a locking bar. The device is made of hard steel and is designed to resist cutting and drilling.
Infringing/ Accused device is called so as it meets the triple identity test of doctrine of equivalence
Function: The infringing device performs the same function as the original, which is to secure a bicycle to a fixed object. Although the shape of the lock is different, the device still locks around the frame of the bicycle and engages with a locking bar to prevent the bicycle from being removed.
Way: The infringing device performs the function in the same way as the original, using a locking mechanism that engages with a locking bar. Although the shape of the lock is different, the mechanism for securing the lock to the bike and engaging it with the locking bar is the same.
Result: The infringing device achieves the same result as the original, which is to resist cutting and drilling. The device is made of hardened steel, just like the original, and is designed to withstand attempts to break it open or remove it from the bicycle.
Factors Considered in Applying the Doctrine of Equivalence
- Functionality of the infringing product or process
- Differences between the infringing product or process and the claimed invention
- Result achieved by the infringing product or process
Examples of situations where the Doctrine of Equivalence is applied
One recent case study demonstrating the doctrine of equivalence in action is Eli Lilly and Company v. Hospira, Inc. decided by the U.S. Court of Appeals for the Federal Circuit in 2020.
Comparison of the Hospira's product to the Eli Lilly’s patented invention
Eli Lilly and Company held a patent for a chemotherapy drug called pemetrexed disodium used to treat non-small cell lung cancer and malignant pleural mesothelioma. Hospira, Inc. produced a generic version of the drug that did not use pemetrexed disodium but instead used a different salt form of the drug called pemetrexed ditromethamine. Hospira argued that their product did not infringe on Eli Lilly’s patent because it did not use the same salt form of the drug as claimed in the Eli Lilly’s patent.
How the doctrine of equivalence fits in the case?
The court applied the doctrine of equivalence and found that Hospira’s product is infringing on Eli Lilly’s patent. The court determined that using pemetrexed ditromethamine instead of pemetrexed disodium was a thin change that did not alter the essential features of the claimed invention (Eli Lilly’s) and that the infringing product achieved substantially the same result in the same way as the claimed invention. The court also found that Eli Lilly had met the “all-elements rule,” which requires that every element of a patent claim be present in an infringing product or process.
What was the decision and impact of the case?
As a result, the court found that Hospira’s product infringed on Eli Lilly’s patent under the doctrine of equivalence and ordered that Hospira was stopped from selling its generic version of the drug until Eli Lilly’s patent expired. This case demonstrates how the doctrine of equivalence can be applied to find infringement even when an accused product does not literally meet all of the elements of a patent claim.
This case also highlights the importance of conducting a thorough patent infringement or patent licensing analysis to identify potential infringement risks and assess the strength and validity of patents.
MCRPL has been helping companies since 2 decades to assess the strength and validity of their patents by identifying prior art that may impact the scope of their patent claims and overcome doctoring of equivalence. By conducting a patent infringement search to provide infringement opinion which can help companied defend patent claims. We help companies better understand the state of the art and the potential risks and opportunities associated with their intellectual property.
Companies can make informed decisions about their intellectual property strategy, avoid potential infringement risks, and ensure their innovations are fully protected in the marketplace. To get a comprehensive patent search contact priorart@molecularconnections.com
