Obviousness

US Patent 12193790 describes wearable devices and remote sensing systems utilizing semiconductor diode light sources with improved signal-to-noise ratios (SNR). An analysis under 35 U.S.C. § 103 for obviousness considers whether the claimed invention, as a whole, would have been obvious to a person having ordinary skill in the art (POSITA) at the time of the invention (the priority date of December 31, 2012), by combining existing prior art references.

The patent itself provides significant background information, describing the state of the art, existing problems, and known techniques, which can be leveraged as indicative of what was known to a POSITA by the priority date.

Independent Claim 1: Wearable Physiological Monitoring Device with LEDs

Key Features of Claim 1:

• A wearable device on the wrist or hand dorsal.
• Measures physiological parameters changing with hand/finger movement.
• LED light source with one or more optical wavelengths.
• Lenses to deliver light to skin tissue.
• Detection system synchronized to the light source, with spatially separated detectors and ADCs.
• Output signal indicative of physiological parameters.
• SNR improved by increasing LED intensity.
• SNR improved by comparing signals when LEDs are off versus on.
• Configured for object identification.

Prior Art and Motivation to Combine:
Before the December 31, 2012 priority date, the field of non-invasive physiological monitoring was well-established. The patent itself notes the existence of "optical instruments [that] tend to be portable and more cost effective as compared to other instrumentation that is conventionally used for medical diagnosis," implying wearable optical sensors were known. [cite: Definitions - Another advantage of such imaging] The challenge of "non-invasive glucose monitoring" requiring "adequate sensitivity and selectivity" was also acknowledged. [cite: Definitions - non-invasive glucose monitoring]

1. Wearable Optical Sensors and LEDs for Physiological Parameters: Wearable devices for measuring physiological parameters, such as pulse oximeters, were common prior to 2012, often employing LEDs as light sources and placed on body parts like the wrist or finger. A POSITA would have been motivated to place such devices on the wrist or hand dorsal, as these are common locations for wearable electronics and provide access to underlying tissue for optical measurements.
2. Spatially Separated Detectors: The use of multiple, spatially separated detectors in optical measurements, particularly diffuse reflection spectroscopy, was a known technique to gather information from different tissue depths or to account for tissue heterogeneity. [cite: Definitions - the detection system also comprises a plurality of detectors that are spatially separated from each other,] A POSITA designing a wearable device for measuring complex physiological parameters in tissue (like skin, which "has many spectral artifacts" [cite: Definitions - the non-invasive procedures]) would have routinely considered using spatially separated detectors to improve data acquisition and signal interpretation.
3. SNR Improvement Techniques:
   • Increasing Light Intensity: The principle that increasing light intensity improves SNR is fundamental in optics and sensor design. [cite: Definitions - the wearable device is also configured to increase the signal-to-noise ratio by increasing light intensity of at least one of the plurality of light emitting diodes from an initial light intensity.] A POSITA would inherently understand and implement this to overcome poor SNR, especially in challenging environments like biological tissue.
   • Background Subtraction (LEDs On/Off): The technique of taking a measurement with the light source off (background) and subtracting it from a measurement with the light source on is a standard method for removing ambient light interference and improving SNR in optical sensing. [cite: Definitions - the detection system is further configured to generate a first signal responsive to light received while the light emitting diodes are off, generate a second signal responsive to light received while at least one of the light emitting diodes is on, and increase the signal-to-noise ratio by comparing the first signal and the second signal.] This technique would have been obvious to a POSITA seeking to improve the accuracy of optical physiological measurements.
   • Synchronization: Synchronizing the detection system to the light source is also a common practice in modulated or pulsed optical systems to enhance SNR by filtering out asynchronous noise. [cite: Definitions - the detection system is configured to be synchronized to the light source.]
4. Physiological Parameters and Object Identification: Measuring parameters responsive to hand/finger movement (e.g., blood flow changes, muscle activity) would be a natural extension of existing wearable physiological monitors. The broad inclusion of "object identification" (where the wearable device is "at least in part configured to identify an object" [cite: Definitions - the wearable device is at least in part configured to identify an object.]) could encompass identifying the user, the activity, or even an external object through integrated cameras or sensors common in smart devices by the priority date.

Conclusion for Claim 1: Combining known elements such as wearable optical sensors, LEDs, spatially separated detectors, and standard SNR enhancement techniques (increasing intensity, background subtraction, synchronization) to measure physiological parameters on the wrist/hand would have been obvious to a POSITA motivated to develop improved and more accurate non-invasive monitoring devices. The inclusion of "object identification" is broad enough to be considered a known function for many wearable devices of the era.

Independent Claim 11: Wearable Physiological Monitoring Device with Semiconductor Diodes and NIR Wavelengths

Key Features of Claim 11:

• A wearable device on the wrist.
• Measures physiological parameters.
• Semiconductor diode light source with one or more optical wavelengths, including NIR (700 nm-2500 nm).
• Lenses to deliver light to skin tissue.
• Detection system synchronized to the light source, with spatially separated detectors and ADCs.
• Output signal indicative of physiological parameters.
• SNR improved by increasing semiconductor diode intensity.
• SNR improved by comparing signals when diodes are off versus on.
• Configured for object identification.

Prior Art and Motivation to Combine:
This claim is highly similar to Claim 1, with the main differences being the specification of "semiconductor diodes" (a broader category than LEDs, encompassing laser diodes) and explicitly defining a "near-infrared wavelength between 700 nanometers and 2500 nanometers."

1. Semiconductor Diodes and NIR: The patent explicitly states 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: Definitions - SWIR light] This shows that semiconductor diodes (including LEDs and laser diodes) were known light sources. Furthermore, the use of near-infrared (NIR) and short-wave infrared (SWIR) light for spectroscopy and medical diagnostics was well-known. The patent highlights that "near-infrared spectroscopy... offers a novel approach to imaging carious regions because scattering is reduced and absorption by stains is low." [cite: Definitions - the near-infrared region of the spectrum] It also describes "Spectroscopy using NIR or short-wave infrared (SWIR) light may be beneficial, because most tissue has organic compounds that have overtone or combination absorption bands in this wavelength range (e.g., between approximately 0.8-2.5 microns)." [cite: Definitions - Spectroscopy using NIR or short-wave infrared (SWIR) light] A POSITA would have been highly motivated to use semiconductor diodes emitting in the NIR range (700-2500 nm) for non-invasive physiological monitoring, given the known advantages of NIR for tissue penetration and detection of specific chemical signatures.
2. Other Features: The remaining features (wearable on wrist, lenses, synchronized detection, spatially separated detectors, ADCs, SNR improvement techniques, object identification) are identical or analogous to those in Claim 1 and are supported by the same prior art and motivations discussed above.

Conclusion for Claim 11: Given the known advantages of NIR/SWIR spectroscopy for tissue analysis and the common use of semiconductor diodes (LEDs, laser diodes) as light sources, it would have been obvious to a POSITA to combine these elements in a wearable device on the wrist, utilizing standard SNR enhancement methods and object identification, to achieve improved physiological monitoring.

Independent Claim 20: Remote Sensing System with Laser Diodes

Key Features of Claim 20:

• A remote sensing system.
• Array of laser diodes generating light with one or more optical wavelengths, including NIR (600 nm-1000 nm).
• At least one laser diode has Bragg reflectors.
• At least one laser diode pulses at a modulation frequency (10 MHz-1 GHz) with an associated phase.
• Light directed to an object.
• Detection system: photodetector(s), lens, spectral filter, processor.
• Measures phase shift and time-of-flight (ToF) of reflected light.
• Generates images based on reflected light amplitude.
• Uses a lock-in technique synchronized to pulsing.
• Processor generates ToF measurement.
• Camera system coupled to lens/processor captures second image.
• Processor combines second image and ToF measurement.
• Communicates with wearable device, smartphone, or tablet.

Prior Art and Motivation to Combine:
Remote sensing technologies, particularly those utilizing lasers (LIDAR), were highly developed by 2012.

1. Remote Sensing with Laser Diodes and NIR: The patent explicitly discusses "Remote sensing or hyper-spectral imaging" and the attractiveness of "SWIR windows" for atmospheric transmission. [cite: Definitions - Remote sensing or hyper-spectral imaging] It also states that "a SWIR super-continuum (SC) source may be able to replace at least in part the sun as an illumination source for active remote sensing, spectroscopy, or hyper-spectral imaging." [cite: Definitions - a SWIR super-continuum (SC) source] Laser diodes were known components for light sources in remote sensing. Using an array of laser diodes to generate NIR light (600-1000 nm) for remote sensing would be an obvious design choice for a POSITA to achieve desired power levels or spectral coverage.
2. Bragg Reflectors in Laser Diodes: Bragg reflectors are commonly integrated into laser diodes (e.g., DFB lasers, DBR lasers) to provide wavelength stability, narrow linewidth, or tunability. Their use in laser diodes for spectroscopic applications, where precise wavelengths are often critical, would have been obvious to a POSITA by the priority date. [cite: Definitions - At least one laser diode of the array comprises one or more Bragg reflectors,]
3. Pulsing, Modulation Frequency, Phase Shift, and Time-of-Flight: Pulsed lasers and measuring time-of-flight (ToF) are fundamental principles of LIDAR for distance measurement and 3D imaging. The use of modulation frequencies in the MHz-GHz range is standard for achieving sufficient range resolution. Measuring phase shifts in modulated light for distance determination (phase-based LIDAR) was also a known technique. [cite: Definitions - the detection system is configured to (i) measure a phase shift... (ii) measure time-of-flight...]
4. Lock-in Technique for SNR: Lock-in amplification is a well-known method for extracting small signals from noisy backgrounds, particularly when dealing with modulated or pulsed signals. [cite: Definitions - the detection system is further configured to use a lock-in technique and configured to synchronize to pulsing of the at least one of the laser diodes,] Synchronizing a lock-in detector to the pulsing of the laser diode for SNR improvement would be an obvious engineering choice for a POSITA.
5. Generating Images based on Amplitude: Generating images based on the amplitude of reflected light is a standard output of remote sensing systems (e.g., intensity images in LIDAR).
6. Combining Camera Images and ToF Data: The combination of 2D optical images (from a camera system) with 3D depth information (from ToF measurements) to create enhanced or 3D representations was a known capability in computer vision and remote sensing for applications like augmented reality, object recognition, or environmental mapping. [cite: Definitions - the remote sensing system including the processor is configured to combine at least a portion of the second image and at least a portion of the time-of-flight measurement to create a combined portion.]
7. Communication with Smart Devices: The communication of data to smart phones, tablets, or wearable devices for display and further processing was a common practice in connected systems by the priority date. [cite: Definitions - value-add services may be provided by wirelessly communicating the monitored data to a handheld device such as a smart phone, and then wirelessly communicating the processed data to the cloud, Definitions - the remote sensing system including the processor is configured to communicate with a wearable device, a smart phone or a tablet that is further configured to process or display some of the combined portion.]

Conclusion for Claim 20: All elements of Claim 20, including the array of laser diodes, Bragg reflectors, pulsed operation, phase shift/time-of-flight measurements, lock-in techniques, integration with cameras, and communication with smart devices, represent combinations of well-known technologies and engineering principles in the field of remote sensing and optical measurement prior to 2012. A POSITA would have been motivated to combine these elements to create a robust and accurate remote sensing system, particularly for applications like "active remote sensing, spectroscopy, or hyper-spectral imaging" where SWIR/NIR light offers advantages. [cite: Definitions - a SWIR super-continuum (SC) source]