US 10874304

US Patent 10,874,304: Near Infrared Measurement Device with Enhanced Signal-to-Noise Ratio

Title: Semiconductor source based near infrared measurement device with improved signal-to-noise ratio

Assignee: Omni Medsci Inc

Inventor: Mohammed N. Islam

Filing Date: October 31, 2019

Issue Date: December 29, 2020

Abstract:
A measurement system or wearable device for physiological parameters is described. This device utilizes a light source with multiple semiconductor sources (e.g., LEDs) that emit near-infrared light between 700 nm and 2500 nm. The system is designed to improve the signal-to-noise ratio by increasing the light intensity from at least one semiconductor source and/or by comparing multiple receiver outputs. For wearable devices, the system can capture light when LEDs are off (first signal) and when at least one LED is on (second signal), and then difference these signals to further enhance the signal-to-noise ratio. The output signal represents a non-invasive measurement of blood constituents in tissue, and can be processed using techniques like Fourier transforms. The system can communicate with a smartphone or tablet for display, storage, and transmission of processed data to a remote device.

Plain-Language Overview of Independent Claims:

US Patent 10,874,304 contains seven independent claims (claims 1, 9, 14, 19, 23, 27, and 33).

Independent Claim 1:
This claim describes a wearable measurement device that includes a light source with several light-emitting diodes (LEDs) for measuring physiological parameters. The device generates a near-infrared optical beam (700-2500 nm) by modulating at least one LED. This beam is delivered to tissue, and the reflected light is received by a receiver with multiple spatially separated detectors and analog-to-digital converters, which produce at least two outputs. The device improves the signal-to-noise ratio by comparing these two receiver outputs and/or by increasing the intensity of the light from at least one LED. It generates an output signal representing a non-invasive measurement of blood within the tissue.

Independent Claim 9:
This claim is similar to Claim 1, describing a wearable measurement device with LED light sources for physiological parameter measurement using near-infrared light (700-2500 nm). It highlights improving the signal-to-noise ratio by increasing LED light intensity. The receiver has multiple detectors, with one detector positioned at different distances from two distinct LEDs, allowing for comparison of the received light from these LEDs to generate the output signal. The receiver is synchronized to the LED modulation, using a lock-in technique to detect the modulation frequency.

Independent Claim 14:
This claim also pertains to a wearable measurement device with LED light sources for physiological measurements using near-infrared light (700-2500 nm). It focuses on improving the signal-to-noise ratio by increasing LED light intensity and by comparing at least two receiver outputs from spatially separated detectors. It further specifies that one detector is situated at different distances from two LEDs, enabling the generation and comparison of signals responsive to light from each LED to form the final output signal. The receiver is synchronized to the LED modulation, employing a lock-in technique for frequency detection.

Independent Claim 19:
This claim describes a wearable measurement device with a light source comprising multiple LEDs for physiological parameter measurement using a near-infrared optical beam (700-2500 nm). The device includes a receiver that captures ambient light when the LEDs are off (first signal) and captured light (including reflected tissue light) when at least one LED is on (second signal). The signal-to-noise ratio is improved by subtracting the first signal from the second signal and by differencing at least two receiver outputs. Additionally, increasing the LED light intensity further improves the signal-to-noise ratio. The device generates an output signal for non-invasive blood measurements.

Independent Claim 23:
This claim is directed to a wearable device similar to Claim 19, using LED light sources and near-infrared optical beams (700-2500 nm) for physiological parameter measurement. The receiver captures light both when LEDs are off (first signal) and when at least one is on (second signal). The signal-to-noise ratio is enhanced by subtracting the first and second signals and by differencing two receiver outputs from spatially separated detectors. The claim also includes improving the signal-to-noise ratio by increasing the light intensity of at least one LED, and generating an output signal for non-invasive blood measurements.

Independent Claim 27:
This claim details a measurement system (which may be wearable) with a light source featuring multiple semiconductor sources that generate a near-infrared optical beam. The system improves its signal-to-noise ratio by increasing the light intensity from at least one of these semiconductor sources. An apparatus receives and delivers an analysis output beam to a sample. A receiver processes the reflected or transmitted analysis beam, generates an output signal, and synchronizes with the light source. The system also includes a smartphone or tablet for receiving, processing, storing, displaying, and wirelessly transmitting the output signal, as well as a remote device for receiving, processing, and storing the transmitted data, including a history of the received status over time.

Independent Claim 33:
This claim focuses on a wearable device designed for use with a smartphone or tablet. It includes a measurement device with multiple semiconductor light sources for physiological parameter measurement. The measurement device generates a modulated input optical beam with one or more optical wavelengths, delivers it to tissue, and receives a reflected portion. The receiver captures light when the semiconductor sources are off (first signal) and when at least one is on (second signal), and synchronizes with the modulation. The signal-to-noise ratio is improved by differencing the first and second signals and by increasing the light intensity from at least one semiconductor source. The device generates an output signal for non-invasive blood measurements and is configured to communicate with the smartphone or tablet, which processes, stores, displays, and transmits the output signal wirelessly.

As a patent attorney, I have investigated litigation involving US Patent 10874304.

Based on the available information, US Patent 10874304 is involved in the following litigation:

• Case Number: IPR2025-01251

  • Jurisdiction: Patent Trial and Appeal Board (PTAB)
  • Status: Pending - Instituted

• Case Number: IPR2025-01584

  • Jurisdiction: Patent Trial and Appeal Board (PTAB)
  • Status: Not Instituted - Procedural

• Case Number: 2:24-cv-01070

  • Jurisdiction: Texas Eastern District Court
  • Status: Active, case filed

• Case Number: 1:25-cv-00140

  • Jurisdiction: Delaware District Court
  • Status: Active, case filed

Details regarding plaintiffs, defendants, and specific filing dates or outcomes for these cases are not fully available in the provided snippets, beyond what is listed above.

Proceedings overview

Two AIA trial proceedings have been filed against US patent 10874304. One proceeding, IPR2025-01584, was denied institution, meaning all challenged claims survived. The other proceeding, IPR2025-01251, has been instituted and is currently active in the trial phase. This indicates that while one challenge was unsuccessful, the patent is still facing a potential claims invalidation in the ongoing trial.

IPR2025-01251 — SAMSUNG ELECTRONICS CO., LTD. et al. v. Omni Medsci Inc

• Type: Inter Partes Review
• Filed: 2025-08-05
• Status: Trial Instituted (The PTAB has decided to move forward with a full review of the challenged claims.)
• Judge panel: Not publicly available yet through the provided information, will require accessing the PTAB E2E system.
• Petition grounds: Not publicly available yet through the provided information, will require accessing the PTAB E2E system. Typically, petitions would challenge claims under 35 U.S.C. §§ 102 and/or 103 using prior art.
• Institution decision: Instituted (date not specified in the provided data, but given a 6-month statutory deadline from filing, institution would have occurred around 2026-02-05). The panel's reasoning for institution is not publicly available yet through the provided information.
• Final Written Decision (if issued): Not yet issued. The statutory deadline for a Final Written Decision is typically one year from the institution date, which would be around 2027-02-05.
• Settlement / termination: No settlement or termination publicly reported.
• Appeal: Not applicable, as a Final Written Decision has not yet been issued.
• Defensive value: This proceeding represents an active threat to the patent's claims. If you are facing assertion, the outcome of this IPR could significantly impact the strength of those assertions. Monitor this proceeding closely for institution details and the eventual Final Written Decision.

IPR2025-01584 — WHOOP, Inc. v. Omni Medsci Inc.

• Type: Inter Partes Review
• Filed: 2025-09-26
• Status: Discretionary Denial (The PTAB declined to institute a trial on the challenged claims.)
• Judge panel: Not publicly available yet through the provided information, will require accessing the PTAB E2E system.
• Petition grounds: Not publicly available yet through the provided information, will require accessing the PTAB E2E system.
• Institution decision: Denied (date not specified in the provided data, but given a 6-month statutory deadline from filing, the denial would have occurred around 2026-03-26). The status explicitly states "Discretionary Denial," meaning the PTAB exercised its discretion under 35 U.S.C. § 314(a) (or related rules such as those from Fintiv) to decline institution, rather than denying based on the merits of the prior art challenge. The specific reasoning for the discretionary denial is not publicly available through the provided information.
• Final Written Decision (if issued): Not issued, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not publicly reported. A denial of institution is generally not appealable to the Federal Circuit, though mandamus petitions are rare exceptions.
• Defensive value: This IPR has concluded with all challenged claims surviving. For a defendant, this means that the specific prior art and arguments raised by WHOOP, Inc. in this petition cannot be re-litigated in another PTAB proceeding by WHOOP, Inc. (or its privies) due to estoppel. However, the discretionary nature of the denial suggests the merits of the prior art were not fully evaluated, and thus similar art might still be used by other parties in future challenges.

Strategic summary

As of today, US patent 10874304 has not had any of its claims cancelled through AIA trial proceedings. In IPR2025-01584, the petition was discretionarily denied, leaving all claims challenged therein intact and untested on the merits at the PTAB. However, IPR2025-01251 is currently in the trial phase, meaning the PTAB has determined that there is a reasonable likelihood that at least one of the challenged claims is unpatentable, and a Final Written Decision on the merits is pending. Therefore, the patent currently has all its claims sustained (relative to IPR2025-01584) or pending a decision (relative to IPR2025-01251). The specific claims under review in IPR2025-01251 are currently untested as to their ultimate patentability at the PTAB.

Regarding estoppel, under 35 U.S.C. § 315(e)(2), the petitioner WHOOP, Inc. (and its privies) is estopped from asserting in any other USPTO or district court proceeding that a claim is invalid on any ground that WHOOP, Inc. raised or reasonably could have raised during IPR2025-01584. Since the denial was discretionary, the specific scope of "reasonably could have raised" can sometimes be debated, but generally covers all art presented. For other defendants, the prior art grounds that WHOOP, Inc. could have raised are still available. For SAMSUNG ELECTRONICS CO., LTD., once IPR2025-01251 concludes with a Final Written Decision, they (and their privies) will be similarly estopped from challenging claims on grounds raised or that reasonably could have been raised in that proceeding. There is no immediate pattern signal of aggressive PTAB appeals by the patent owner yet, as no Final Written Decision has been issued.

Recommended next steps

For anyone facing assertion of US10874304, the primary focus should be on IPR2025-01251. This proceeding is active and could result in claims being invalidated.

• Monitor IPR2025-01251: Access the PTAB E2E system to obtain the institution decision for IPR2025-01251 to identify precisely which claims were instituted for review and on what grounds (prior art and statutory bases). The statutory deadline for the Final Written Decision in IPR2025-01251 is approximately 2027-02-05 (one year from the estimated institution date of 2026-02-05). Key upcoming milestones would include the patent owner's response, petitioner's reply, potential oral hearing, and ultimately the Final Written Decision.
• Review IPR2025-01584: While denied institution, it is still advisable to review the petition and denial decision for IPR2025-01584 (once available through PTAB E2E) to understand the prior art previously considered by the PTAB and the basis for the discretionary denial. This can inform strategies for any potential new IPR challenges by third parties.
• Assess untested claims: Any claims not challenged or instituted in IPR2025-01251, or not challenged in IPR2025-01584, remain untested at the PTAB and represent potential targets for future challenges by other parties, should new prior art be available.

To obtain the specific documents for these proceedings, navigate to the USPTO PTAB E2E system and search for the proceeding numbers IPR2025-01251 and IPR2025-01584.

Inventors

Mohammed N. Islam, Sc.D. The inventor is noted as a tenured Professor of Optics and Photonics and Professor of Biomedical Engineering at the University of Michigan, and is also the founder and Chief Technology Officer for several companies, including Omni MedSci, Inc. and Cheetah Omni.

Original assignee

Omni Medsci Inc. is the entity named as the original assignee on the issued patent US10874304 and remains the current assignee. It is unclear if Omni Medsci Inc. ships a product embodying the claims of this patent. While the company is described as part of "the Omni family of companies, which create, develop, and commercialize Dr. Islam's optical technology in various fields", and a related entity, Omni Sciences Inc., works on developing and marketing lasers, Omni Medsci Inc. itself has been identified as a Non-Practicing Entity (NPE) by Unified Patents. The primary line of business for Omni Medsci Inc. appears to be the development and commercialization of optical technology, significantly through patent licensing and assertion in the healthcare and medical device sectors. Omni Medsci Inc. is currently an operating entity, actively asserting its patents, including US10874304, in multiple litigation campaigns.

Assignment timeline

No post-issuance assignments for US10874304 have been recorded in the USPTO Patent Assignment Search database. The patent was assigned by the inventor, Mohammed N. Islam, to Omni Medsci Inc. on the application filing date (2019-10-31), as indicated in the Google Patents legal events.

Timeline diagram

timeline
    title Ownership of US 10874304
    2019 : Application filed by Omni Medsci Inc
    2020 : Patent issued to Omni Medsci Inc
    2024 : Litigation filed in E.D. Texas
    2025 : Litigation filed in D. Delaware
         : PTAB IPR2025-01584 filed
         : PTAB IPR2025-01251 filed

NPE / troll-pattern signals

1. Shell-entity transfer — unclear
   While Omni Medsci Inc. is identified as an NPE by Unified Patents and its business model appears centered on patent assertion, there is no recorded transfer of US10874304 from a clear operating company to a shell entity in the USPTO assignment records. The patent was assigned by the inventor directly to Omni Medsci Inc. at the time of application filing. Although other patents by the same inventor have seen transfers between various "Omni family" LLCs, this specific patent's direct chain does not show such a transfer.

2. Known asserter in the chain — present
   Omni Medsci Inc. is currently asserting US10874304 in multiple infringement lawsuits against companies such as Fossil, OnePlus, Oura Health, Samsung, and WHOOP. Unified Patents explicitly designates Omni Medsci Inc. as an NPE.

3. Repeat correspondent across the chain — unclear
   As there are no recorded post-issuance assignments for US10874304 in the USPTO database, there is no assignment chain to evaluate for recurring correspondent attorneys or firms.

4. Cascading transfers — not present
   No cascading transfers are present, as there are no recorded post-issuance assignments for US10874304.

5. Pre-litigation transfer — not present
   No pre-litigation transfer is present. The patent was assigned to Omni Medsci Inc. at the time of application filing in 2019, while the earliest identified litigation for this patent began in 2024.

6. Bankruptcy fire-sale — not present
   There is no information in the provided sources indicating that Omni Medsci Inc. has filed for bankruptcy or that the patent was acquired through a bankruptcy sale.

7. Privateering — unclear
   While Omni Medsci Inc. is an NPE asserting patents from its founder, Mohammed Islam, there is no explicit evidence from the provided sources to confirm that this assertion is conducted on behalf of an operating company against its competitors.

8. Defensive aggregator (anti-NPE) — not present
   The patent is currently owned and actively asserted by Omni Medsci Inc., not by a defensive aggregator. Unified Patents, a defensive aggregator, has in fact initiated prior art contests targeting Omni Medsci's patents, identifying them as NPEs.

Verdict

NPE — high confidence
The current assignee, Omni Medsci Inc., is a known patent asserter explicitly identified as an NPE by Unified Patents. This patent, US10874304, is central to ongoing infringement litigation campaigns initiated by Omni Medsci Inc. in 2024 (e.g., Eastern District of Texas case 2:24-cv-01070) and 2025 (e.g., Delaware District Court case 1:25-cv-00140), among other legal challenges. This extensive and sustained litigation activity, combined with the NPE designation, strongly supports the conclusion that Omni Medsci Inc. operates primarily as a patent licensing and assertion entity rather than a product-shipping company.

USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/

I'll research the patent citations for US 10,874,304. Let me search for the cited prior art references.

I found the patent. Now let me retrieve the complete "References Cited" list from the patent's front page.

Let me get the complete references cited list from the patent documents.

Prior Art Analysis — US Patent 10,874,304

Ground-truth confirmation of the target patent

The search confirms the following identifying data for the requested number (interpreted literally, no auto-correction):

⚠️ Contradiction to flag before the prior-art analysis

The previously generated "Patent summary" section states the patent has seven independent claims (1, 9, 14, 19, 23, 27, and 33) and characterizes claim 1 as a "wearable measurement device … with a plurality of LEDs." This contradicts the actual granted claim set.

The actual granted claims (per RPX Insight and the patent PDF submitted as Exhibit 1100 in the PTAB proceedings) show:

• Claim 1 — A measurement system comprising: a light source of a plurality of semiconductor sources; a measurement device; a receiver (including "capture light while the semiconductor sources are off … first signal" and "capture light while at least one … is on … second signal," and "differencing the first signal and the second signal"); a smart phone or tablet; and a cloud ("receive … an output status … process … and store the processed data").
• Claim 11 — A wearable measurement device … "and a cloud configured to receive over the wireless transmission link an output status … and wherein the cloud is capable of storing a history."
• Claim 19 — A wearable device for use with a smart phone or tablet …

The claim text quoted in the earlier summary (LED-based claims 1/9/14/19/23/27/33) appears to be text drawn from the specification's preferred-embodiment paragraphs, not from the granted claims of this patent. It may correspond instead to a related family member (e.g., US 11,241,156 or another continuation). Treat the earlier claim-numbering as unreliable for § 102 mapping; the operative claims of US 10,874,304 are the "measurement system / cloud" claims (1, 11, 19, …).

Because I could not retrieve the complete, contiguous "References Cited" list within the search budget, I report below exactly what the sources returned and explicitly mark what I could not verify, rather than fabricating a full list.

A. U.S. Patent Documents cited on the face of US 10,874,304

The front page "(56) References Cited — U.S. PATENT DOCUMENTS" list is only partially rendered in the accessible sources. The references confirmed verbatim from the patent PDF (Exhibit 1100 in IPR2025-01250 and PGR2025-00063) are:

1. US 4,063,106 A — "Ashkin et al." — issued Dec. 1977

• Citation: U.S. Patent No. 4,063,106 A, Ashkin et al., Dec. 1977.
• Publication/filing date: Issued December 1977.
• Description: Listed first on the front-page reference list. (I do not have a verified title/abstract from the retrieved sources and will not guess — Ashkin's early work relates to optical/laser manipulation, but I have not confirmed the subject matter of this specific patent.)
• § 102 relevance: None apparent. This is a 1977 optical-physics reference; it does not disclose a wearable NIR LED physiological monitor with smartphone/cloud connectivity. It cannot anticipate any operative claim of US 10,874,304.

2. US 4,158,750 A — "Sakoe et al." — issued Jun. 1979

• Citation: U.S. Patent No. 4,158,750 A, Sakoe et al., Jun. 1979.
• Publication/filing date: Issued June 1979.
• Description: Listed on the front page. (Again, no verified title retrieved.)
• § 102 relevance: None apparent for the operative "measurement system + cloud" claims. If anything, a 1979 reference of this type relates to signal/pattern processing generally and would at most be § 103 background, not § 102 anticipation.

3. CA 2458123 A1 — 2004

• Citation: Canadian Patent Application CA 2458123 A1 (published 2004).
• Date: September 2004.
• Description: Foreign patent document cited on the front page.
• § 102 relevance: To be confirmed; on the face of the retrieved data its subject matter is not verified. It predates the priority date, so it is available as prior art, but I cannot map it to a specific claim without the reference's disclosure.

4. CN 101849821 A — 2010

• Citation: Chinese Patent Application CN 101849821 A (published 2010).
• Date: October 2010.
• Description: Foreign patent document cited on the front page.
• § 102 relevance: Predates the priority date; potentially available. Mapping to a claim requires the reference's disclosure, which was not retrieved.

Note on completeness: The accessible front-page data also indicates the reference list continues ("(Continued)") with additional U.S. patents, and the retrieved snippets show the list truncated immediately after "4,158,750 A … Sakoe." The full text citing document (the patent PDF) is available at patentimages and via Google Patents US10874304B2 and Justia. I was unable to enumerate the remaining entries within the search budget and will not invent them.

B. Non-patent literature / "Other Publications" cited

The front page includes an "OTHER PUBLICATIONS" section. The one entry confirmed is:

5. Petition for Inter Partes Review, [Apple Inc.](/litigations/by-plaintiff/Apple%20Inc.) v. Omni MedSci, Inc., IPR2020-00175 (U.S. Pat. No. 10,188,299)

• Citation: "Inter Partes Review No. IPR2020-00175; Petition for Inter Partes Review of U.S. Pat. No. 10,188,299; Apple Inc. v. Omni MedSci, Inc."
• Description: A prior IPR petition against a related Omni MedSci patent in the same family (the '299 patent is a family member — see the priority chain in the patent's "Definitions" section). Cited as a prosecution/prior-art document.
• § 102 relevance: This is a procedural/prior-art-of-record citation, not itself anticipating art. It is relevant because it shows the Examiner was aware of the Apple challenge to the parent family and considered the art therein (including the Anthony declaration and the '533 Patent grounds).

C. Prior art actually relied on in current challenges (the practically important set)

Because the front-page citations are mostly old/low-relevance references, the operative prior art for this patent is the art raised in the live PTAB challenges, which is the material you asked about functionally. Confirmed from the PTAB docket (Unified Patents / Docket Alarm):

• US 6,078,833 A — "Self Referencing Photosensor" / monitoring system — surfaced on the Unified Patents page for US10874304 (portal.unifiedpatents.com/patents/patent/US-6078833-A). This is the type of reference a petitioner uses to attack the "capture light while LEDs off → first signal; LED on → second signal; difference the two" limitation (present in granted claims 1 and 19) and the "self-referencing/ambient-light-subtraction" concept. A self-referencing photosensor with on/off differential measurement is a strong § 102 candidate against the differencing limitations of claims 1 and 19 (and dependent claims) — and a strong § 103 anchor for the synchronized-detection claims.
• The Samsung filings — PGR2025-00063 and IPR2025-01249/01250/01251/01252 (filed 2025-08-05 and 2025-11-12) — each attach US10874304B2 as Exhibit 1001/1058/1100 and rely on a "Declaration of Brian W. Anthony" plus the record of prior IPRs (IPR2019-00916 on the '533 patent, IPR2021-00453 on the '484 patent). Those IPR records (Exhibits 1005–1016) contain the actual claim-by-claim prior-art mappings being re-used here.
• WHOOP, Inc. v. Omni Medsci, Inc. — IPR2025-01584; filed 2025-09-26; discretionarily denied (procedural, not merits). Its petition/art was never reached on the merits.

To obtain the specific claim-by-claim § 102 mappings (i.e., which reference is asserted against which claim of '304), the operative documents are PGR2025-00063 and IPR2025-01249/01250/01251/01252 petitions and Exhibit 1003/1100-series declarations, retrievable from PTAB E2E / the Unified Patents portal. The petitions are public; the specific grounds were not fully visible in the retrieved snippets.

D. Direct answers: which claims each reference potentially anticipates (§ 102)

E. Overall assessment

• The front-page patent citations (US 4,063,106; US 4,158,750; CA 2458123; CN 101849821) are, on their face, not anticipatory of the operative claims; they read as generic/old optical and signal-processing art. I could not enumerate the full list, so I cannot rule out that another front-page reference is more relevant.
• The commercially/material prior art is the set raised in the Samsung PGR/IPRs — in particular US 6,078,833 A (Self-Referencing Photosensor), which is the kind of reference that directly targets the patented "off-state vs. on-state differential + receiver synchronization" limitations found in granted claims 1 and 19.
• Caveat (stated per operating rules): I was unable to retrieve a complete, verified copy of the full "References Cited" list or the full petition grounds within the search budget. I have reported only references I can ground in a source and have explicitly marked unverified items rather than fabricating descriptions or claim mappings. For a definitive § 102 chart, pull the full patent PDF front page and the PGR2025-00063 / IPR2025-01251 petitions from PTAB E2E.

Key sources:

• Google Patents — https://patents.google.com/patent/US10874304B2/en
• Patent PDF (front page, Exhibit 1100) — https://www.docketalarm.com/cases/PTAB/IPR2025-01250/SAMSUNG_ELECTRONICS_CO._LTD._v._OMNI_MEDSCI_INC/docs/11-07-2025-Petitioner/Exhibit-1100-Ex_1100___US10874304.pdf
• RPX Insight claim text — https://insight.rpxcorp.com/patent/US10874304B2
• Unified Patents IPR2025-01251 — https://portal.unifiedpatents.com/ptab/case/IPR2025-01251
• Unified Patents US-6078833-A page — https://portal.unifiedpatents.com/patents/patent/US-6078833-A

Based on the information provided within US Patent 10,874,304, particularly its descriptions of existing techniques and challenges, and considering a priority date of December 31, 2012, a person having ordinary skill in the art (PHOSITA) would have been motivated to combine known elements to arrive at the claimed inventions. The patent itself outlines the landscape of prior art and problems, thereby revealing motivations for the claimed improvements.

The core of the independent claims (1, 9, 14, 19, 23, 27, and 33) revolves around a wearable device or measurement system that uses near-infrared (NIR) semiconductor light sources (e.g., LEDs) for non-invasive physiological measurements, with a focus on improving the signal-to-noise ratio (SNR) and integrating with modern communication technologies.

Elements of Prior Art / General Knowledge (as described in US 10,874,304):

1. Near-infrared (NIR) Spectroscopy for Physiological Measurements: The patent acknowledges that "near-infrared spectroscopy such as absorption spectroscopy or near-infrared diffuse reflection or transmission spectroscopy" was a known method for investigating materials, including for non-invasive procedures on blood constituents. [cite: "near-infrared spectroscopy such as absorption spectroscopy or near-infrared diffuse reflection or transmission spectroscopy.", "the non-invasive procedures have often transmitted or reflected light through the skin, but skin has many spectral artifacts in the near-infrared that may mask the glucose signatures."] The patent also mentions that "SWIR light may be generated by light sources such as lamps, light emitting diodes, one or more laser diodes, super-luminescent laser diodes, and fiber-based super-continuum sources." [cite: "SWIR light may be generated by light sources such as lamps, light emitting diodes, one or more laser diodes, super-luminescent laser diodes, and fiber-based super-continuum sources."]
2. Semiconductor Light Sources (LEDs): Light Emitting Diodes (LEDs) were known as suitable light sources, particularly in the SWIR wavelength range, offering "higher power level...and with higher energy efficiency" compared to lamps, and being "solid state components that emit a wavelength band that is of moderate width." [cite: "LED's can be used that have a higher power level in the SWIR wavelength range.", "LED's also produce an incoherent beam, but the power level can be higher than a lamp and with higher energy efficiency.", "LED's are solid state components that emit a wavelength band that is of moderate width, typically between about 20 nm to 40 nm."] The patent also notes that "the LED output may more easily be modulated, and the LED provides the option of continuous wave or pulsed mode of operation." [cite: "Also, the LED output may more easily be modulated, and the LED provides the option of continuous wave or pulsed mode of operation."]
3. Improving SNR by Increasing Light Intensity: The patent explicitly states that "a higher light level or intensity may improve the signal-to-noise ratio for the measurement." [cite: "the selection of the constituent of interest may be improved using a number of techniques. For example, a higher light level or intensity may improve the signal-to-noise ratio for the measurement."] This is a fundamental principle in optical sensing.
4. Differential Measurements for Noise Reduction: The patent describes a technique for performing a "differential measurement" by placing one probe over a vein-rich region and a second probe over a region without distinct veins, and then "subtracting" the outputs to "at least partially cancel out the features from the skin." [cite: "a near-infrared diffuse reflectance measurement may be performed by placing one probe 603 above the vein-rich region 601 . To turn this into a differential measurement, a second probe 604 may be placed above a region without distinct veins 602 .", "the outputs from the two probes may be subtracted 605 to at least partially cancel out the features from the skin.", "the differential measurements may be intended to compensate for or subtract out (at least in part) the interference from the skin."] This illustrates the known concept of using spatially separated detectors for background or common-mode noise subtraction.
5. Ambient Light Subtraction: While presented as part of the invention, the concept of "capturing light while the LEDs are off and convert the captured light into a first signal, and to capture light while at least one of the LEDs is on and convert the captured light into a second signal... by differencing the first signal and the second signal" is a common and well-known method for removing ambient light interference in optical sensing.
6. Modulation and Lock-in Techniques: The patent describes that the receiver is configured to be "synchronized to the modulation of the at least one of the LEDs," and to use a "lock-in technique that detects the modulation frequency." These are standard, effective techniques for extracting weak signals from noisy backgrounds.
7. Wearable Devices and Smartphone/Remote Connectivity: The patent discusses "a wearable device" and "a measurement system... with a smart phone or tablet, and a remote device." [cite: "a wearable device includes a measurement device including a light source comprising a plurality of light emitting diodes (LEDs) for measuring one or more physiological parameters", "a measurement system is provided with a light source, an apparatus, a receiver, a smart phone or tablet, and a remote device."] By 2012, wearable physiological monitors and their integration with smartphones for data display, storage, and cloud-based communication were well-established trends in health technology. [cite: "schematically shows that the medical measurement device can be part of a personal or body area network that communicates with another device (e.g., smart phone or tablet) that communicates with the cloud."]
8. Analog-to-Digital Converters (ADCs) and Digital Signal Processing: The patent refers to "one or more analog to digital converters coupled to the spatially separated detectors." [cite: "the receiver may also be coupled to analog to digital converters, particularly if the signal is to be fed to a digital device."] The use of ADCs to digitize sensor outputs for further processing (e.g., "Fourier transform and mathematical manipulation") was standard practice. [cite: "the output signal is generated at least in part by using a Fourier transform and mathematical manipulation of a signal resulting from the captured light."]

Obviousness Combinations and Motivation:

A PHOSITA, seeking to improve the accuracy and usability of non-invasive NIR physiological measurements in wearable devices (a known application), would have found it obvious to combine the aforementioned prior art elements.

Scenario 1: Combination for Claims 1, 9, 14 (SNR improvement via intensity and differential measurement)

• Starting Point: A known wearable device employing NIR LEDs for physiological measurements (e.g., a basic pulse oximeter adapted for the wrist or ear).
• Motivation to Increase Light Intensity: Faced with low signal levels or poor SNR, the PHOSITA would be directly motivated by the explicit knowledge that "a higher light level or intensity may improve the signal-to-noise ratio." [cite: "the selection of the constituent of interest may be improved using a number of techniques. For example, a higher light level or intensity may improve the signal-to-noise ratio for the measurement."] This is a fundamental and predictable engineering solution.
• Motivation for Spatially Separated Detectors and Comparing Outputs (Differential Measurement): To address interfering signals, such as skin artifacts or motion noise, the PHOSITA would be motivated to apply known differential measurement techniques. The patent itself illustrates this by describing probes over vein-rich and non-vein regions with signal subtraction to cancel skin features. [cite: "a near-infrared diffuse reflectance measurement may be performed by placing one probe 603 above the vein-rich region 601 . To turn this into a differential measurement, a second probe 604 may be placed above a region without distinct veins 602 .", "the outputs from the two probes may be subtracted 605 to at least partially cancel out the features from the skin.", "the differential measurements may be intended to compensate for or subtract out (at least in part) the interference from the skin."] Extending this concept to use multiple spatially separated detectors in a wearable device, and comparing their outputs, for common-mode rejection, would be a logical and predictable step for a skilled artisan.
• Motivation for Modulation and Lock-in (Claims 9, 14): When dealing with weak optical signals immersed in noise (including ambient light), modulating the LED source and employing a synchronous detection method like a lock-in amplifier is a well-established and highly effective technique to isolate the signal of interest. The patent identifies this as a feature of the receiver.

Scenario 2: Combination for Claims 19, 23, 33 (SNR improvement via ambient light subtraction and intensity increase)

• Starting Point: A known wearable device employing NIR LEDs for physiological measurements.
• Motivation for Ambient Light Subtraction (LEDs off vs. on): A significant challenge for wearable optical devices is ambient light interference. A PHOSITA would be motivated to implement a known solution for ambient light rejection, such as taking a reading with the LEDs off (background) and subtracting it from a reading with the LEDs on (signal + background). This "differencing the first signal and the second signal" is a routine design choice for optical sensors to improve SNR.
• Motivation to Increase Light Intensity: As in Scenario 1, increasing light intensity is a direct and known method to improve SNR.
• Motivation for Spatially Separated Detectors and Comparing Outputs (Claims 19, 23): As in Scenario 1, this provides a known mechanism for further noise and interference reduction.

Scenario 3: Combination for Claim 27 (Measurement system with remote connectivity)

• Starting Point: A known measurement system utilizing semiconductor sources for optical analysis of a sample, providing an output signal, with a receiver synchronized to the light source.
• Motivation to Increase Light Intensity for SNR: The same fundamental motivation applies as above.
• Motivation for Smartphone/Tablet and Remote Device Integration: The widespread adoption of smartphones and tablets for data collection, display, and communication, along with the growth of cloud-based health monitoring systems, would have made it obvious for a PHOSITA to integrate a physiological measurement device with these technologies. The patent explicitly illustrates this architecture. [cite: "schematically shows that the medical measurement device can be part of a personal or body area network that communicates with another device (e.g., smart phone or tablet) that communicates with the cloud."] The benefits of data storage, visualization, historical tracking, and remote consultation are clear and would drive such integration.

Overall Conclusion on Obviousness:

The independent claims of US 10,874,304 appear to describe a combination of elements and techniques that were individually known in the art prior to the patent's priority date of December 31, 2012. The motivations for combining these elements—specifically to improve signal-to-noise ratio in non-invasive physiological measurements, mitigate interference (e.g., from skin or ambient light), and enhance usability through wearable design and connectivity—are explicitly recognized problems and solutions within the patent's own description of the field. A PHOSITA, seeking to overcome these known problems, would have found these combinations to be predictable and obvious applications of existing technological principles and routine engineering choices.

To determine the patent term adjustments (PTA), patent term extensions (PTE), continuation applications, divisional applications, related family members, and the projected expiration date for US Patent 10,874,304, I would typically access the Public PAIR or Patent Center system on the USPTO website. However, since I cannot directly access those live systems, I will rely on the provided patent text and general knowledge about how these terms are applied.

Based on the provided patent text and general USPTO rules:

Patent Term Adjustments (PTA):
Patent Term Adjustment (PTA) is granted to compensate for delays caused by the USPTO during the prosecution of a utility or plant patent application. The patent document itself does not explicitly state the PTA amount. This information is usually found on the issue notification or in the patent's file wrapper in Patent Center. Without direct access to the USPTO's official patent records for US10874304, the precise PTA cannot be determined.

Patent Term Extensions (PTE):
Patent Term Extensions (PTE) are available for patents on certain human drugs, food or color additives, medical devices, animal drugs, and veterinary biological products to restore time lost during premarket government approval from a regulatory agency. The patent, US10874304, is related to a "Semiconductor source based near infrared measurement device," which could potentially fall under the "medical devices" category. However, the provided text does not indicate whether a PTE application has been filed or granted for this patent. Such information would typically be found in the patent's image file or in the USPTO's lists of PTE applications and granted extensions.

Continuation and Divisional Applications, and Related Family Members:
The patent text explicitly states its lineage, indicating it is part of a larger family of applications:
"U.S. application Ser. No. 16/506,885 is also a continuation of U.S. application Ser. No. 16/188,194 filed Nov. 12, 2018 (now U.S. Pat. No. 10,386,230), which is a continuation of U.S. application Ser. No. 16/004,154 filed Jun. 8, 2018 (now U.S. Pat. No. 10,126,283), which is a continuation of U.S. application Ser. No. 15/855,201 filed Dec. 27, 2017 (now U.S. Pat. No. 9,995,722), which is a continuation of U.S. application Ser. No. 15/711,907 filed Sep. 21, 2017 (now U.S. Pat. No. 9,897,584), which is a divisional of U.S. application Ser. No. 14/109,007 filed Dec. 17, 2013."
It also lists other related applications:

• "U.S. application Ser. No. 16/506,885 is also a continuation of U.S. application Ser. No. 16/241,628 filed Jan. 7, 2019 (now U.S. Pat. No. 10,441,176), which is a continuation of U.S. Ser. No. 16/015,737 filed Jun. 22, 2018 (now U.S. Pat. No. 10,172,523), which is a continuation of U.S. Ser. No. 15/594,053 filed May 12, 2017 (now U.S. Pat. No. 10,188,299), which is a continuation of U.S. application Ser. No. 14/875,709 filed Oct. 6, 2015 (now U.S. Pat. No. 9,651,533), which is a continuation of U.S. application Ser. No. 14/109,007 filed Dec. 17, 2013."
• "U.S. application Ser. No. 16/506,885 is also a continuation of U.S. application Ser. No. 16/284,514 filed Feb. 25, 2019, which is a continuation of U.S. application Ser. No. 16/016,649 filed Jun. 24, 2018 (now U.S. Pat. No. 10,213,113), which is a continuation of U.S. application Ser. No. 15/860,065 filed Jan. 2, 2018 (now U.S. Pat. No. 10,098,546), which is a Continuation of U.S. application Ser. No. 15/686,198 filed Aug. 25, 2017 (now U.S. Pat. No. 9,861,286), which is a continuation of U.S. application Ser. No. 15/357,136 filed Nov. 21, 2016 (now U.S. Pat. No. 9,737,235), which is a continuation of U.S. application Ser. No. 14/875,709 filed Oct. 6, 2015 (now U.S. Pat. No. 9,651,533), which is a continuation of U.S. application Ser. No. 14/109,007 filed Dec. 17, 2013."

From the provided text, the earliest priority date mentioned is December 17, 2013, derived from U.S. application Ser. No. 14/109,007.

Projected Expiration Date:
For U.S. utility patents filed on or after June 8, 1995, the patent term is generally 20 years from the earliest filing date of the patent application, or the earliest application to which priority is claimed under 35 U.S.C. §§ 120, 121, or 365(c). This 20-year term can be adjusted by PTA or extended by PTE.

The earliest priority date mentioned in the patent text is December 17, 2013, for U.S. application Ser. No. 14/109,007. Therefore, the base expiration date (before any adjustments or extensions) would be 20 years from this date.

Base Expiration Date = December 17, 2013 + 20 years = December 17, 2033.

The Google Patents page itself lists "Anticipated expiration: 2033-12-17" under its legal status section, which aligns with the 20-year term from the earliest priority date. This date does not appear to include any Patent Term Adjustments (PTA) or Patent Term Extensions (PTE), as those would typically extend the term beyond the 20-year anniversary of the earliest priority date. Since the patent was issued on December 29, 2020, and the filing date of the application (US16/669,794) was October 31, 2019, there could be PTA granted due to USPTO delays in examination or issuance. However, the precise PTA amount would need to be confirmed by reviewing the official USPTO file history in Patent Center.

Therefore, the projected expiration date listed on Google Patents is December 17, 2033. This date is based on the 20-year term from the earliest priority claim, without accounting for potential PTA or PTE. [cite: "Anticipated expiration 2033-12-17"]