Today the U.S. Patent and Trademark Office officially granted Apple a patent that relates to portable electrocardiogram devices. More specifically, described embodiments can relate to portable electrocardiogram devices that are wearable and can include an antenna. The patent describes an Apple Watch working in concert with a specialized armband accessory. Due to Apple's original patent filing date, it's unknown whether Apple's granted patent is describing a future armband device to work with Apple Watch to perform a superior cardiac monitoring system in the future or is a system that Apple has passed on.

Conventional electrocardiogram monitor devices require at least two electrodes to be in physical contact with a user to complete a circuit in order to monitor the electrical activities of the heart of the user. One electrode is often required to be attached near the heart of the user to detect the electric field of the heart. Such arrangement often requires the user to maintain a certain posture. Hence, it can be difficult to continuously conduct electrocardiogram monitoring in a prolonged period because the movement of the user can be severely limited.

Embodiments described in this granted patent can relate to cardiac monitor devices that can detect the electrical activities of a heart through a single electrode. An exemplary cardiac monitor device can include an electrode that is configured to be in contact with a limb of a user. The cardiac monitor device can also include an antenna that is capacitively coupled with the body of the user using air as the dielectric. The antenna can serve to replace a second electrode.

The electrode can generate a first electrical potential that represents the electrical potential of the limb of the user. The antenna, when capacitively coupled with the body, can generate a second electrical potential that represents the electrical potential of the heart. By determining the potential difference between the electrode and the antenna, the electric field of the heart can be monitored remotely through the antenna.

Since the cardiac monitor device can detect the electric field of the heart with a single physical contact point, the antenna and the electrode can be carried by a single housing. For example, in one case, a small consumer electronic device can include a housing that carries both the antenna, the electrode and circuitry that connects the two components.

The consumer electronic device can take the form of an armband that can be worn by the user. The armband can have the capability to wireless communicate with another electronic device such as a smartphone, a tablet, or a smart watch so that the cardiac information can be transmitted and displayed by the other electronic device.

In another example, the cardiac monitor device can be a component that is part of a smart watch. Since a single device that is wearable by a user can be used to monitor the electric field of a heart, the electrical activities of the heart can be monitored continuously in a prolonged period, such as in days or even in months.

Apple's patent FIG. 1 below illustrates an exemplary cardiac monitor device (Armband #100). A cardiac monitor device can take different forms, including a wearable device that can be removably coupled to a user's appendage. In the particular case shown in FIG. 1, cardiac monitor device 100 can take the form of an armband that can be removably coupled to a user. While the cardiac monitor device is shown as being worn at upper arm #104 of the user, the cardiac monitor device can also be worn at other locations of user including, but not limited to, the wrist, leg, neck, or body.

Apple's patent FIG. 2 below is a system schematic box diagram of a system for displaying real time cardiac information of a user. Cardiac monitor device #100 can include a detection circuitry (#124) that can include an antenna (#110) and an electrode (#112). The electrode that can directly measure a first electrical potential of the user at limb (left arm #104). The Antenna can form a capacitor (#126) with heart (#106) through capacitive coupling.

Through determining and amplifying the potential difference between the first electrical potential and the second electrical potential, detection circuitry (#124) can generate signals or data representing the electrical activities of THE heart.

The cardiac monitor device (Armband #100) can optionally include an analog-to-digital convertor capable of digitalizing the potential difference before the signals are transmitted or stored in a memory as digitized data. The cardiac monitor device can include an output that can transmit signals carrying information of the potential difference to an external circuit. The output can take various forms. In one case, the output can be a transceiver (#128).

The external circuit can be carried by a portable electronic device. For example, cardiac monitor device (Armband #100) can be paired with electronic device (Apple Watch #118) so that signals or data representing the electrical activities of heart can be transmitted from transceiver (#128) to transceiver (#130) of the electronic device (Apple Watch #118).

The Apple Watch can include processor (#132) that can analyze the signals and data. In some cases, the processor can also issue a command to control cardiac monitor device (Armband #100). The command can be transmitted from the transceiver (#130) to transceiver (#128) to control cardiac monitor device.

The processor can also generate signals that can represent potential differences between the electrode (#112) and the antenna (#110), which can represent the electrical activities of heart. The visual presentation of cardiac information can take the form of heart rate, electrocardiography, and/or other suitable presentations. The processor can provide analysis of a user's health condition based on the cardiac information and/or based on the current electrical activities of heart compared to historical data of heart. Processor can in turn cause display assembly (#136) to issue a notification regarding the electrical activities of the heart based on the analysis.

Apple's patent FIG. 9 below is a flowchart depicting a method 900 for monitoring cardiac information of a person.

For more details, review Apple's granted patent 11,083,383. Apple filed for this patent in September 2018. Apple Watch with ECG was introduced in December 2018. This would suggest that today's granted patent was a follow-up invention to Apple's ECG invention that went to market three months after this filing. Why file this invention if they already knew that their ECG feature for Apple Watch was coming to market months later? Likely because this is a possible future accessory that could provide some users with more complicated heart conditions with a superior cardiac monitoring system.   

Two of the inventors include Mechanical Engineer Chiachi wu (Mechanical Engineering at National Taiwan University) and Engineer Shu Lin.