Understanding the Formats of Patent Claims Involving Controllers: Best Practices for Patent Prosecution Professionals

Patent claims including a controller are ubiquitous in the information age. When dealing with such patent claims—particularly those programmed to perform specific functions—there is a variety of formats from which patent professionals may select. Each format can impact the scope of the patent's protection, its enforceability, and its ability to be defended from prior art attacks. This post explores different claim formats for controllers and their implications, and illustrates an example from a recent PTAB decision where the format resulted in an intended user interpretation.

As background, some example formats are illustrated below. While these examples illustrate some variation, there are many alternative options used by practitioners.

1. "A controller configured to [perform a specific function]" This format attempts to emphasize the configuration of the controller to achieve certain actions or operations. It suggests that the controller is intentionally designed to execute particular tasks. For example:

   • "A controller configured to manage data transfer between devices."

2. "A controller that [performs specific actions]" This phrasing focuses on the functional role of the controller without specifying the means by which it achieves the actions. For example:

   • "A controller that regulates temperature in a climate control system."

3. "A controller with a processor and memory holding instructions to [perform specific functions]" This format details the components of the controller and explicitly states that the memory holds instructions for performing certain functions. This format tends to be more susceptible to a structural interpretation:

   • "A controller with a processor and memory holding instructions to execute user commands and manage device operations."

4. "A controller structured so that [it carries out certain functions]" This phrasing tries to imply structure with explicit use of the term and focuses on a generic structural configuration of the controller that enables it to perform specific functions. There may be an implication that the design of the controller inherently leads to the execution of certain actions. For example:

   • "A controller structured so that it can automatically adjust lighting based on ambient light levels."

5. "A controller including [specific components or features] to [achieve certain actions]" This format includes a description of specific controller components and their purpose, often providing a balance between detail and function. For example:

   • "A controller including a network interface and a sensor module to monitor and report environmental conditions."

The USPTO does not view these claim formats equally, sliding between functional and structural limitations depending on the particular language and facts of each case. Some formats may be more susceptible to intended use interpretations, which could render the claim invalid in that the functional limitations may be ignored.

As a quick refresher, the law of intended use refers to the principle that system or device claims should be directed to specific structures or functions rather than merely describing the intended use of the invention. Under MPEP 2111, claim features that focus on the intended use rather than the actual structure or method of operation are particularly vulnerable to being disregarded in that prior art need not show them to support a rejection. See some previous posts (here, here).

In a recent PTAB case, Appeal 2023-002852, Application 15/755,088, Danaher appealed a rejection for a biomanufacturing apparatus for cell culturing. Claim 1 is reproduced below, with the controller language emphasized:

1. A biomanufacturing apparatus, comprising a housing, a substantially enclosed bioreactor chamber inside the housing and a further substantially enclosed region inside the housing containing at least one of electrical parts and electronic control components, the chamber including: a tray for supporting a bioreactor, a tray support including a mechanism for rocking the tray in use the tray including a heater for contacting a bioreactor and heating the same, a sensor for measuring temperature of the bioreactor, and the apparatus further comprising secondary heating for heating air surrounding the tray, wherein the mechanism for rocking the tray is configured to move a plate holder back and forth about a pivot axis below the tray, further comprising a controller that controls the heater and the secondary heating to heat the bioreactor to a set point temperature such that the bioreactor and the air surrounding the bioreactor are maintained at substantially the same temperature during the heating, wherein the controller is coupled to the sensor, wherein the secondary heating comprises means for drawing air from the enclosed region, heating the drawn air, and for forcing the heated air into the chamber

On appeal, Danaher argued that the cited references failed to show the controller controlling the heaters as claimed. The PTAB found that the controller limitations were merely intended use (citations omitted):

Appellant’s arguments do not identify reversible error in the Examiner’s rejection. Claim 1 does not use “configured to” language as argued by Appellant. Nor does Appellant’s Specification describe the controller as having a particular configuration or programming such that the controller causes the heater and secondary heater to heat the bioreactor to a set point temperature such that the bioreactor and the air surrounding the bioreactor are maintained at substantially the same temperature during heating. Thus, we construe the language “that controls the heater and the secondary heating to heat the bioreactor to a set point temperature such that the bioreactor and the air surrounding the bioreactor are maintained at substantially the same temperature during the heating,” as functional language that recites an intended use or purpose of the controller.

Drafting patent claims involving controllers requires careful consideration of the claim format and its implications. Consider the desired scope during examination, and prosecution, as well as in foreign jurisdictions. If you have any questions or need further guidance on drafting controller-related claims, feel free to reach out or consult with experienced patent professionals.