Apple has been granted a patent (number 11513004) for “terahertz spectroscopy and imaging in dynamic environments.” It hints at an Apple Watch with sensors for detecting skin cancer.
About the patent
In the patent filing, Apple notes that today’s sensor technologies (e.g., metal-oxide (MOX) gas sensors, electrochemical gas sensors) can detect a few gases but have several disadvantages. For example, integrating a gas sensor on an electronic device requires an aperture or opening to allow air to flow onto the gas sensor so that the gas can be detected.
The design of an aperture into a consumer electronic device poses several challenges. The aperture may degrade water resistivity of the device. Also, the size of the aperture may be constrained due to a tradeoff between form factor and gas detection capability. In addition to aperture constraints, the number of gases detected by a given sensor is limited and one sensor cannot detect gas, liquid and solid materials. Integrating multiple sensors on the consumer electronic device to detect gas, liquid and solid materials would increase the size and cost of the consumer electronic device.
Also, many of today’s gas sensors have a high idle-time current consumption to maintain the properties of the sensor. For example, MOX gas sensors have heating elements that are used to maintain a certain temperature of the sensor at all times. Also, the accuracy of today’s gas sensors drift over time requiring periodic calibration.
Apple says that, in addition to detecting the presence of gas, health/quality of liquid or solid materials in an environment, there is need for imaging applications on consumer electronic devices related to health monitoring, such as detecting skin cancer and other skin disorders. The conventional image sensors (e.g., CMOS image sensors) found on consumer electronic devices, however, are incapable of performing such health monitoring applications. Apparently, Apple wants to change this.
Summary of the patent
Here’s Apple’s (highly technical) abstract of the patent: “Embodiments are disclosed for terahertz spectroscopy and imaging in dynamic environments. In an embodiment, a transmitter of an electronic device emits a continuous electromagnetic (EM) wave in the terahertz (THz) frequency band into a dynamic environment that includes a transmission medium that changes over time. A receiver of the electronic device, receives an EM wave reflected off an object in the environment and determines a spectral response of the reflected EM wave.
“The spectral response includes absorption spectra at a frequency in the THz frequency band that is indicative of a known target transmission medium. The absorption spectra of the target transmission medium and a path length of the reflected EM wave signal are used to obtain the concentration level of the target transmission medium from a reference library of known concentration levels.”