FIELD OF THE DISCLOSURE

The present disclosure relates to health care. More particularly, but not exclusively, the present disclosure relates to methods, systems, and apparatus for

implementing a body channel communication and power distribution system (also referred to as a Body Area Power Network).

BACKGROUND OF THE INVENTION

With the rising trend in aging population, attention is increasing being given to health and well-being, and the domain of at-home monitoring is growing as a consequence. For example the new Philips' Biosensor patch enables continuous home monitoring of vital signs such as ECG, heart rate, respiration rate, skin temperature and activity. The clinical data is sent to and processed on a cloud based platform and supports the healthcare professionals in their clinical decision making. The Biosensor patch could prevent hospital readmissions by detecting health deterioration in the home setting as early as possible. Besides stick-to-skin patches there are other solutions available on the market such as health watches, monitoring belts/straps and health monitoring T-shirts, insertable devices, and so forth.

Although existing at-home monitoring solutions have clear advantages and added value they are still not optimal. It is envisioned that the next generation wearables and/or insertables will be either temporary tattoos (extremely unobtrusive, ultrathin, skin contour/topography conforming films adhering to the skin by van der Waals forces) or permanent insertables which are placed under the skin. Insertables may be particularly advantageous because they are unnoticed by the user and provide more ecofriendly alternatives to disposables.

Linhua Zhang. Xinzhuo Liu, fin .Huang and Lei Wang in their document entitled "Baseband system for human body channel communication," published in International Conference on Biomedical Engineering and Informatics, 2010 IEEE, describe a method for using human body communication ("HBC") for data transmission for low-power and highspeed biomedical sensors. To make such a sensor network economically and practically feasible, it would be beneficial to harness power in a manner that provides for a very long operational lifetime. Therefore, to enable long-term medical monitoring, power consumption of the sensor should be minimized. Most sensors' power budgets are dominated by storing acquired data to memory or transmitting the information off the sensor node. What more, biological signals, such as the electrocardiogram ("ECG") and electroencephalogram

("EEG"), are often recorded in areas of the human body where attaching sensors with large form factors would not be comfortable and therefore are not compatible with long term recording. However, while making sensors light and with small form factors may decrease battery size, decreasing battery sized may also reduce operational lifetime.

SUMMARY OF THE INVENTION

Existing technologies related to using human body channel communications have the limitation in that they only enable exchange of data, e.g., detected by biomedical sensors. One non-limiting object of the present disclosure is to overcome this limitation. In various embodiments, a body channel communication system may be provided that includes: a base unit arranged to a transmit a (in some embodiments data modulated) RF signal via a body channel; and a receiver arranged to receive the RF signal from the body channel;

characterized in that the system further comprises a converter (328) arranged to convert the RF signal into energy to power the receiver.

In some embodiments, the receiver may be wearable, on-body electronic device. In other embodiments, the receiver may be an insertable device for intradermal or subcutaneous insertion into tissue. In various embodiments, both the base unit and the receiver may be capacitive coupled to a body channel via electrodes. In various

embodiments, the converter may be an energy harvesting unit (328) to charge an energy storage component in the receiver.

In various embodiments, the system may further include one or more sensors configured to detect one or more physiological parameters. In various embodiments, the energy converted from the RF signal may power the one or more sensors. In various embodiments, the system may further include a transmitter configured to transmit one or more detected physiological parameters from the receiver to the base unit. In various embodiments, the energy converted from the RF signal may power the transmitter. In various embodiments, the system may further include a memory component configured to store data indicative of one or more detected physiological parameters. In various embodiments, the energy converted from the RF signal may power the memory component. BRIEF DESCRIPTION 01 THE DRAWINGS

Fig. 1 depicts an example of how central nodes (e.g., transmitter) and receiver nodes may be arranged on a human body, in accordance with various embodiments.

Figs. 2A and 2B schematically depict examples of how central nodes may be operably coupled with receiver nodes in accordance with various embodiments.

Fig. 3 schematically depicts an example of how a central node may transmit a signal to one or more receiver nodes, in accordance with various embodiments.

Fig. 4 depicts an example method of practicing various aspects of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring now to Fig. 1 , in various embodiments, a patient 100 may carry, wear, or otherwise possess a central node ("CN") 102 (also referred to as a "base unit" and/or a "transmitter ^" ) that includes an abundant power source, such as a rechargeable battery. Central node 102 may come in various forms, such as a smart phone, a wearable smart device (e.g., smart watch, smart glasses, jewelry, belts, bands, etc.), or another electronic device that includes a power sources such as a rechargeable battery. In various embodiments, central node 102 may be operably coupled with the body of patient 100 ( e.g., outer surface of the patient ^' s skin) in various ways, such as via capacitive coupling (which may not require direct contact between electrodes and skin, and may. for instance, occur even with one or more layers of clothing between the electrode and the skin), dry electrode coupling ( e.g., using conductive polymers, conductive textiles, etc. ), galvanic coupling ( e.g., using electrodes that are wetted or gelled), and so forth.

Patient 1 00 may also utilize one or more receiver nodes 104 ( also referred to as "receivers ^" ), five (N1 -N5) of which are depicted in Fig. 1 located at various portions of a body of patient 100. In various embodiments, a receiver node 104 may take various forms, such as a patch or tattoo-type device affixed to the skin of patient 100 (e.g., using

biocompatible adhesives, van der Waals forces, etc. ), a wearable device such as a watch or belt, and/or an insertable device that is inserted (e.g., intradermally, subcutaneously, etc. ) beneath the skin of patient 100. Each receiver node 104 may be configured to detect one or more health parameters of patient, including but not limited to ECG, EEG, pulse rate, respiration rate, body temperature, sweat levels, glucose, and so forth. Like central node 102, each receiver node may be operably coupled with the body of patient 100 in various ways, such as capacitive coupling, dry electrode coupling, galvanic coupl ing, and so forth. In various embodiments, central node 102 may be configured to a transmit a radio frequency ("RI ") signal, which in some cases may be modulated with data, via one or more body channels 108 to one or more receiver nodes 104. In various embodiments, a body channel 108 may include an impedance network (see Fig. 2) that lies within the living body between the central node 102 and a receiver node 104. As will be described below, these body channels 108 (and their inherent impedance networks) may be leveraged to exchange data and power between central node 102 and one or more receiver nodes 104.

Each receiver node 104 may be configured to receive the data modulated RI signal from a respective body channel 108. In various embodiments, each receiver node 104 may include a converter (described in more detail below) configured to convert the RI signal received from central node 102 into energy to power the receiver node 104, e.g., via an internal battery or capacitor. Accordingly, central node 102 and receiver nodes 104, along with body channels 108 defined through patient 100, collectively may form a body channel communication and power distribution system 106.

It is known from various literature that when a signal is transmitted through the human body in the range of about 10 MHz to 100 MHz, the human body attenuates the signal by a maximum of 45dB for a distance of 40cm from central node 102 to receiver node 104. Thus, by properly positioning central node 102 on patient 100, e.g., centrally located to be within a predetermined distance of all receiver nodes 104, multiple wearable and/or insertable receiver nodes 104 can be powered remotely using human body transmission. By creating such an on-demand powering mechanism, the constraints on battery size may be reduced, and in some cases the requirement of an integral battery to power a receiver node 104 may be eliminated. And in some embodiments, a central node 102 carried by one patient could be used to power one or more receiver nodes 104 worn/used by another patient, e.g., when the two patients make physical contact (e.g., shake hands, hug, etc.).

Figs. 2A and 2B schematically depict examples of how central nodes 102 may be operably coupled with receiver nodes 104 via one or more body channels (108) within or on the human body, in accordance with various embodiments. In Fig. 2A, central node 102 (which as depicted includes an AC power source such as a battery) may be capacitive coupled with a first portion 210A of a tissue surface of a patient (e.g., outer layer of the patient's skin). In particular, the capacitors schematically indicated at 214i and 214 ₂ may be formed between electrodes of central node 102 and the first portion 21 OA of the conductive tissue surface. Similarly, the capacitors schematically indicated at 214 ₃ and 214 ₄ may be formed between electrodes of receiver node 104 and another portion 210B of the conductive tissue surface (e.g., the location on the skin at which a patch or tattoo is affixed). Between capacitor pairs 214i, 214 ₂ and 214 ₃ , 214 ₄ lies an impedance network 212 formed within the patient's tissue (i.e., a "body channel"), e.g., beneath the epidermis. Consequently, an electrical signal (e.g., generated at central node 102 and/or receiver node 104) can pass between central node 102 and receiver node 104 through impedance network 212 via capacitors 214i _-4 . In some embodiments, the capacitors 214i and 214 ₂ may form a high-pass filter with an input resistance of the intervening conductive tissues (e.g., in which impedance network 212 is formed). Another high-pass filter may be formed between the input resistance of receiver node 104 and the capacitors 214 ₃ and 214 ₄ . These two high-pass filters may create, for instance, a 40dB/decade roll-off of the input signal applied from central node 102.

Fig. 2B schematically depicts a similar arrangement, except that instead of being worn on the tissue surface, receiver node 104 is implanted beneath the surface of the tissue. Fig. 2B includes many of the same components and arrangements, particularly on the central node 102 side, as Fig. 2A. However, rather than receiver node 104 being capacitive coupled with a tissue surface, electrodes of receiver node 104 are directly coupled with impedance network 212 formed within the tissue. In some embodiments such as that depicted in Fig. 2B, there may be only one high-pass filter formed at the central node 102 side, which may provide, for instance, a 20dB/decade roll-off.

A body channel (108 in Fig. 1) defined between central node 102 and receiver node 104 may, in some cases, be dominated by the high-pass filter formed by the capacitive coupling between the human body and the impedance network 212 the conductive tissues. Additionally, for relatively low transmission frequencies, the human body may act as a single node, which may be evidenced by a lack of variation of channel gain at various distances between central node 102 and receiver node 104. As the transmission frequency increases, the wavelength of the signal becomes comparable or smaller with respect to the size of the human body. As a consequence, from a single node model, an effect akin to a surface wave phenomenon occurs such that the channel gain depends on the distance between central node 102 and receiver node 104.

Fig. 3 schematically depicts an example of how central node 102 may transmit a signal to one or more receiver nodes 104, in accordance with various embodiments. In various embodiments, central node 102 may include a signal generator 322. Signal generator 322 may be configured to generate a RF signal of a particular frequency (e.g., between about 10 MHz and about 100 MHz) and apply that signal to electrodes 324 attached to the skin (or at least close enough to facilitate capacitive coupling). In some embodiments, signal generator 322 may modulate the signal with various information, such as identifiers associated with one or more receiver nodes 104, commands to be implemented by the one or more receiver nodes 104, and so forth. The RF signal may be transmitted via electrodes 324 through one or more body channels 108 and towards electrodes 326, which may be integral with or otherwise in communication with receiver node 104.

Receiver node 104 may include an energy harvester 328 (also referred to as a "convertor"), an energy storage component 330, and one or more sensors 332. Energy harvester 328 may be configured to harvest electrical energy from the RF signal received via electrodes 326 from central node 102. In some embodiments, energy harvester 328 may convert an incoming AC signal to a DC signal. Energy harvester 328 may be implemented in various ways. Non-limiting examples of how RF charging may be implemented are described in "Ambient RF Energy Harvesting Technologies for Self-Sustainable Standalone Wireless Sensors Platforms," by Sangkil, et al. (2014). IEEE Micro., which in applicable jurisdictions is incorporated herein by reference in its entirety. For example, components such as a folded dipole antenna, a five-stage RF-DC convertor, and/or an RF-DC charge pump may be used to harvest power from an RF signal.

Energy storage component 330 may store energy harvested by energy harvester 328. Energy storage component 330 may take various forms, such as a rechargeable battery, one or more capacitors, etc. One or more sensors 332 or other measuring circuitry may be configured to detect various physiological parameters of the patient, such as vital signs, etc. In various embodiments, one or more sensors 332 may be powered with electricity harvested by energy harvester 328 and stored in energy storage component 330. Note that the coupling between electrodes 324/326 and the patient may accomplished in various ways, such as capacitive coupling, dry electrode coupling, galvanic coupling, and so forth.

In some embodiments, techniques described herein may be applied by a system that also communicates using a body network - for example using the so-called Active Digital Aura ("ADA") approach. In such embodiments, central node 102 may generate both data communication signals and power transfer signals. In some embodiments, such signals may be generated sequentially, e.g., on demand. In other embodiments, data communication signals and power transfer signals may be combined, e.g., using frequency modulation of the power transfer signal to communicate information/data whilst transferring power. For example, a Manchester encoded signal transmission may be used to combine both data and power within a single signal. In some embodiments, the combined transmission may be a broadcast communication. The receiver node(s) 104 being addressed may perform both energy harvesting and communication, while non-addressed nodes may simply harvest energy.

Fig. 4 depicts an example method 400 of practicing various aspects of the present disclosure. While particular operations of method 400 are depicted in a particular order, this is not meant to be limiting. One or more operations may be added, omitted, and/or reordered. At block 402, a wearable or insertable device, e.g., receiver node 104, may be placed on or in a patient. As noted above, receivers 104 may be placed at a variety of locations, such as on the patient's limbs, chest, back, neck, face, forehead, etc. In some embodiments, receiver nodes 104 may be incorporated into clothing (e.g., undergarments, t- shirts, socks, etc.) and/or accessories (e.g., belts, watches). In other embodiments, receiver nodes 104 may be worn on the skin (e.g., as patches, tattoos, etc. and/or inserted beneath the skin, e.g., intradermally, subcutaneously, etc.).

At block 404, an RF signal may be generated, e.g., by signal generator 322 of central node 102, and transmitted (e.g., via electrodes 324) through one or more body channels (e.g., 108). In various embodiments, the transmitted RF signal may or may not be modulated with data. In some implementations, the transmitted RF signal may be broadcast throughout the patient's body, e.g., so that it is detectable by a plurality of receiver nodes 104 on or within the patient's body. In other embodiments, other communication schemes may be employed, such as multicast, unicast (e.g., by transmitting directionally), etc. At block 406, the RF signal may be received, e.g., by receiver node 104 via one or more body channels 108 by way of one or more electrodes 326.

At block 408, the RF signal may be converted into energy, e.g., by energy harvester 328. At optional block 410, the converted energy may be at least temporarily stored in an energy storage component (e.g., 330). At block 412, the converted (and in some cases, temporarily stored) energy may be used to power various components of the receiver node. For example, in some embodiments, the converted energy may be used to power one or more physiological parameter sensors 332. In some embodiments, the converted energy may be used to power one or more transmitters integral with the receiver node (e.g., as part of a transceiver), e.g., so that the receiver node may transmit various information, such as one or more detected physiological parameters, back to the central node. In yet other embodiments, the converted energy may be used to power a memory component (not depicted) of the receiver using the converted energy, e.g., to store (at least temporarily) data such as physiological parameters detected by sensor(s) 332. While several inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.

All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.

The indefinite articles "a" and "an," as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean "at least one."

The phrase "and/or," as used herein in the specification and in the claims, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and/or" should be construed in the same fashion, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the "and/or" clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and/or B", when used in conjunction with open-ended language such as "comprising" can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

As used herein in the specification and in the claims, "or" should be understood to have the same meaning as "and/or" as defined above. For example, when separating items in a list, "or" or "and/or" shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. In general, the term "or" as used herein shall only be interpreted as indicating exclusive alternatives (i.e. "one or the other but not both") when preceded by terms of exclusivity, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in the claims, shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently "at least one of A and/or B") can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

In the claims, as well as in the specification above, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of and "consisting essentially of shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 21 1 1.03. It should be understood that certain expressions and reference signs used in the claims pursuant to Rule 6.2(b) of the Patent Cooperation Treaty ("PCT") do not limit the scope.