While Apple is traditionally quiet about its upcoming designs (for IP reasons, understandably), the tech giant does nod to the general direction of its technology in its publicly-applied patents.
Apple recently filed three patents centered around health-monitoring advancements in both direct and indirect applications—from glucose monitoring and clinical sleep analytics to augmented vision.
An image of Apple’s blood oxygen sensor on their Apple Watch 6. This is an example of a medical-focused sensor that Apple has created in the past. Image used courtesy of Apple
These patents cite unique use cases in the following technologies:
- Infrared transceivers with beam-steering technology, coupled with visible light capture and display (patent application: 20210041291)
- Performance enhancements for terahertz spectroscopy with a focus on variable incident EM angles (patent application: 20210041376)
- Sleep sensors based on multiple laterally adjacent substrates in a single layer (patent application: 20210038092)
Augmented Object Recognition Using Visible and Infrared Light
This patent application for beam-steered infrared light sensing in devices refers to “device 10” as having multiple orientations for the display (labeled as “14” in the diagram below) depending on the device’s use.
Diagram of “device 10,” including the housing and elements of the proposed application for infrared sensing. Image used courtesy of the US Patent Office
These uses could include cellular telephones or a head-mounted device.
The device can characterize objects based on received spectra of varying light intensity according to the detailed description. The patent claims that the device has the ability to perform optical sensing in the visible light, ultraviolet, and infrared light spectrum ranges.
It also proposes to support automated beam-steering operations via positional data including orientation and tilt.
Apple’s infrared patent application shows a simple cross-section drawing of an enclosure containing elements, such as PCB (labeled 44), components (labeled 42), and optical elements shown in window arrangement (labeled 30W).
Traditionally, IR sensing has a broad range of applications, including movement detection, proximity, and tilt detection.
The new patent indicates that a user may want to check on food items using optical sensing to evaluate ripeness, calorie content, etc. This sensing can analyze food through pattern matching depending on size, shape, color, shininess, and other attributes of the object or food.
Speculatively, this could apply to vision impairment situations where users require object recognition and characterization to assist with daily life.
Non-invasive Glucose Analysis with Terahertz Radiation?
Apple has filed a second application for an electromagnetic (EM) device operating in the terahertz frequency range. This device’s purpose appears to be the characterization of liquids, solids, or plasma in a “dynamic environment.”
This sensing advancement could potentially apply to glucose concentrations in the bloodstream, alleviating a long-standing painful process of sampling blood sugar levels for diabetic individuals.
The specific use for this patent is vague, with details indicating that the “electronic device transmitting/receiving the THz EM waves is changing, and/or the location and/or orientation of one or more objects reflecting the THz waves in the environment are moving.”
This statement could indicate that this device could be used in wearable technology.
A key feature of the device for improved SNR is the use of multiple polarizations in transmission and reception. Image used courtesy of the US Patent Office
RF designers might have their interest piqued by this design having multiple polarizations. Point-to-point EM applications have often suffered signal quality issues regarding polarization with losses occurring due to antenna misalignment.
By analyzing additional details in the application, this device appears to quantify the concentrations of gases in the environment surrounding the device, including detecting carbon monoxide (CO) based upon absorption spectra at 0.692 THz.
Like other RF devices, terahertz radiation sensors can operate based on the heterodyne principle (downconversion) or through direct detection. One of the governing criteria for choosing the receiver method is whether or not phase information (heterodyne) is important to the designer.
The specific applications for using these two technology patents are unclear, but it seems Apple generally intends to use this technology to increase health monitoring.
Characterizing Sleep Patterns with High-technology Bedding
The final Apple patent technology focuses on collecting biometric data related to the quality of sleep. This technology’s key feature is its thin form factor and flexibility to not disturb the user while sleeping.
The sensor technology electrodes are multiple layers of substrates, which generate signals based upon force mechanisms such as the user’s position in bed, heartbeat, and breathing metrics.
In the proposed device, the dotted rectangle (100), is meant to be a non-intrusive biometric monitoring platform composed of inter-stitched layers of electrodes. Image used courtesy of the US Patent Office
The specific advantage of this patent over traditional sleep monitoring lies in manufacturing each layer of the platform. Multiple materials in each layer substrate allow for operation performance while “reducing wasted material (and decreasing material costs), reducing an overall thickness of the sleep monitor, increasing a flexibility of the sleep monitor, and simplifying manufacturing.”
This figure is an image of the cross-sectional design of the layered sensor. Image used courtesy of the US Patent Office.
Flexible PCB design is increasingly common with E-CAD software integrating features that support rigid-flex designs.
Apple’s new patent applications have interesting technology potential for all EEs, from object recognition using infrared to sensor technology embedded in a bedsheet.
Is commercial health monitoring of interest to you? Do you work with biotechnology applications focused on consumer biometric data? Share your stories in the comments below.