PTAB

IPR2017-01554

Fitbit Inc v. Valencell Inc

Key Events

Petition

petition

Title: Wearable Light-guiding Bands for Physiological Monitoring
Brief Description: The ’269 patent discloses a wearable monitoring device, such as a finger ring, for measuring physiological information using photoplethysmography (PPG). The device comprises a band with a generally cylindrical inner body made of light-transmissive material and an outer body, which together guide light to and from a subject's body.

Prior Art Relied Upon: Asada (H. Asada et al., “Mobile Monitoring with Wearable Photoplethysmographic Biosensors,” IEEE Engineering in Medicine and Biology Magazine, May/June 2003).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Asada, which discloses the “MIT Ring Sensor,” teaches every element of independent claim 1. Asada’s device is a wearable ring sensor band with a layered structure that corresponds to the claimed inner and outer body portions. It includes a light-transmissive material (Layer 3), a cladding material for optical shielding (Layer 2), windows for an LED emitter and photodetector, and describes their optical communication to measure physiological signals from a finger. Asada’s disclosure of a finger-worn ring also allegedly meets the limitations of dependent claim 2.
- Key Aspects: Petitioner contended that while Asada’s figures do not explicitly label all components, a person of ordinary skill in the art (POSA) would have readily understood the layered structure and function of the ring sensor, which was well-known in the art.

Prior Art Relied Upon: Asada (as cited above) and Hannula (Patent 7,190,986).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Asada’s sensor design could be modified with teachings from Hannula to arrive at the inventions of claims 4 and 5. Hannula teaches using a reflective mask surrounding a photodetector to increase the amount of light captured, which Petitioner mapped to the "light reflective material" of claim 4. For claim 5, Petitioner relied on Asada’s disclosure of a dual photodetector design and signal processor to cancel motion artifacts, where a second detector provides a noise reference signal.
- Motivation to Combine: A POSA would combine Hannula’s reflective mask with Asada’s sensor to improve signal quality, a key objective discussed in Asada. For claim 5, the motivation was inherent in Asada, which explicitly teaches using a second photodetector and signal processor to attenuate motion noise, a well-known problem in the field.
- Expectation of Success: Combining these known elements for their intended purposes—improving signal quality and reducing noise—would have yielded predictable results.

Prior Art Relied Upon: Goodman (Patent 4,830,014).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Goodman, which discloses a flexible, layered adhesive sensor for monitoring vital signs, renders claim 1 obvious. Goodman's sensor, though initially flat, is intended to be wrapped around a finger or nose, thereby taking on a "generally cylindrical" shape. Its layered construction, including an opaque vinyl strip (outer body) and a clear polyester layer (inner light-transmissive body), allegedly meets the structural limitations of claim 1. Goodman also discloses applying the sensor to a digit or nose, meeting the limitations of claim 2.
- Key Aspects: A central part of this argument is that a POSA would understand that a flat, flexible sensor becomes "generally cylindrical" in its intended use, bringing it within the scope of the claim.
Additional Grounds: Petitioner asserted numerous additional obviousness challenges. These grounds relied on Asada or Goodman as a primary reference, combined with secondary references to teach specific, well-known features. For example, combinations with Hicks (Patent 6,745,061) were used to add a lens region (claim 3), combinations with Delonzor (Patent 5,797,841) were used to add light-blocking material (claim 8), and combinations with Al-Ali (Application # 2007/0123763) were used to add an optical filter (claims 9-10).

"generally cylindrical": Petitioner proposed the construction "having a convex shape." This construction was argued to be consistent with the specification and necessary to properly read on prior art devices, like Goodman's, that are flexible and conform to a body part, rather than being rigidly cylindrical.
"cladding material": Petitioner proposed "a material that blocks or reflects at least some light." This construction was based on the function of the material as described in the patent—to optically shield and guide light—and the specification’s disclosure that it could be made of "virtually any type of material."
"near": Petitioner proposed "within a short distance." This construction was offered based on the plain and ordinary meaning of the term, as the patent did not provide a specific definition.

Petitioner argued that the Board should institute trial on all twelve grounds because they are not unduly burdensome. The grounds were presented as two distinct sets of challenges: one based primarily on Asada and the other on Goodman. Petitioner contended that potential claim construction rulings could affect the strength of one set of grounds versus the other, and therefore, in the interest of justice, both independent challenges should proceed to ensure the patentability of the challenged claims was fully addressed.

Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of the ’269 patent as unpatentable under 35 U.S.C. §103.