Apple acquired sleep-tracking app company Beddit in 2017. Since then, Apple engineers have filed a series of patents that have been shown to advance the Beddit system or come up with new alternative sleep-tracking systems: 01, 02, and 03. Last Thursday. , the US Patent and Trademark Office published a patent application from Apple, which once again appears to advance the Beddit system.
More specifically, Apple’s patents cover sensor systems that include force sensors, vibration sensors, piezoelectric sensors, and/or such sensors. The sensor or sensor system can be or include a piezoelectric force sensor and can be used in a bed or elsewhere to sense vibrations, including vibrations generated by sound. Sensed vibrations may include user-generated biological vibrations or sounds, such as heart vibrations and/or lung vibrations. In particular, force sensors can include resonant microstructures to mechanically amplify vibration signals within a particular biological range of interest while the vibration signals are being collected.
Piezoelectric sensor with resonant microstructure
Apple’s new sensor system invention may feature a sensor stack. The sensor stack may comprise a piezoelectric film having a first side opposite a second side and including an array of microstructures, each microstructure of the array of microstructures corresponding to a biological vibration. A first electrode is connected that is tuned to resonate within the biological range of interest. The first and second electrodes convert biological vibrations detected by at least one microstructure of the array of microstructures into electrical signals.
In some embodiments, each microstructure of the array of microstructures can have a cantilever structure, and the cantilever structure can be tuned to amplify the detection of biological vibrations.
In some embodiments, the sensor stack further comprises a first shielding membrane coupled to the first electrode and a second shielding membrane coupled to the second electrode. A first electrode may be disposed between the piezoelectric film and the first shield film, and a second electrode may be disposed between the piezoelectric film and the second shield film.
In some embodiments, the array of microstructures may be a first array of first microstructures. The biological range of interest can be a first biological range of interest. The piezoelectric film can further include a second array of second microstructures. Each of the second array of second microstructures can be tuned to a second biological range of interest. The second biological range of interest can be different than the first biological range of interest.
A first biological range of interest may correspond to a first range of lung oscillations from 50 Hertz to 2500 Hertz. A second biological range of interest may correspond to cardiac oscillations in a second range of 20 Hertz to 500 Hertz.
A sensor system may be provided for monitoring bio-vibrations generated by a user. The sensor system can include a flexible sensor that detects biological vibrations from a user while the user is in contact with the flexible sensor. The flexible sensor may comprise a flexible piezoelectric film that includes an array of microstructures, each microstructure of the array of microstructures defining a respective hole in the flexible piezoelectric film and corresponding to the biological area of interest. Each has a cantilever structure that amplifies vibrations detected within. A first surface of the piezoelectric film and a second surface of the piezoelectric film are respectively connected, the first surface facing the second surface, and a differential amplifier electrically connected to the first electrode and the second electrode. to provide a differential amplifier. An output indicative of the detected vibrations sensed by the array of piezoelectric film microstructures.
FIG. 1 below of the Apple patent shows an exemplary sensor system, including force sensors, that can be used to detect and monitor biological vibrations. figure. 4 illustrates a chart containing examples of different types of biological vibrations, along with approximate ranges of biological interest corresponding to each illustrated type of biological vibration; figure. Figure 3 shows an example of a force sensor that can be used to detect biological vibrations; figure. FIG. 4 shows an exemplary piezoelectric film containing an array of microstructures that can be used as part of a force sensor as described in FIG. 3.
In one example, Apple points out that Microstructure #450 can be tuned to a specific frequency, such as a frequency of 500 Hz, to primarily amplify sound and/or biological frequencies that vibrate at or near 500 Hz. increase. Additionally or alternatively, a given microstructure is tuned over a wider than specific biological range of interest, such as between 100 Hz and 6 kHz. This extended biological coverage generally corresponds to vibrations and/or sounds emanating from the user’s lungs. In such cases, the microstructure amplifies the sounds and vibrations coming from the human lungs.
For more information, check Apple’s patent application number US 20220409095 A1. One of Apple’s inventors is OS Power Engineering Manager Zheng Zeng.
