Implantable device for monitoring human health and different health conditions

Abstract

A device arranged for full subcutaneous implantation is disclosed, the device comprising an electrochemical sensor for sensing at least one analyte, and a near field communication (NFC) interface for percutaneously transmitting information sensed by the electrochemical sensor.

Description

[0001] The present disclosure relates to devices, apparatus, systems and methods for sensing analytes, particularly but not limited to implantable devices for sensing analytes in the human body. Background Art

[0002] Physiological monitoring is fundamental to the diagnosis, prognosis and evolutionary assessment of many medical conditions, such as cardiovascular, neurological, muscular, endocrine conditions, etc. Conventionally, body surface measurements using equipment such as electrodes are performed to monitor parameters and physiological substances associated with such conditions.

[0003] However, there is a need for improved methods for on-demand monitoring of analytes within a subject or patient, particularly for sensing analytes within tissue of a subject. Summary of the invention

[0004] An invention is set forth in the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Specific examples will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0006] Figure 1 A printed circuit board assembly for an implantable device is shown;

[0007] Figure 2 A cross-section of a portion of an implantable device is shown;

[0008] Figure 3 A cross section of an implantable device is shown;

[0009] Figure 4 shows a scanning electron microscope image of an implantable device;

[0010] Figure 5 A schematic diagram of an electronic circuit for an implantable device is shown;

[0011] Figure 6 An exemplary NFC data communication packet is shown;

[0012] Figure 7 A method of encrypting data for NFC transmission is shown;

[0013] Figure 8 A method of sensing an analyte is shown. DETAILED DESCRIPTION

[0014] Disclosed herein is an implantable device or apparatus arranged to be implanted completely subcutaneously, the apparatus comprising an electrochemical sensor for sensing at least one analyte, and a near field communication (NFC) interface for transcutaneously (or percutaneously) transmitting information sensed by the electrochemical sensor.

[0015] Conventional commercial implants are used to detect and / or deliver electrical stimulation through biopotential channels (or electrodes), and typically do not perform electrochemical sensing of analytes. Conventional implants are typically powered by batteries.

[0016] The implantable device and / or apparatus disclosed herein is advantageously arranged to be implanted in subcutaneous tissue for electrochemical sensing of analytes, thereby providing physiological data sensing at the tissue level. In particular, the implantable device and / or apparatus can be completely implanted subcutaneously, such as completely under the human skin, such as in the human trunk. Therefore, the sensing provided by the implantable device provides "supra-cell" monitoring of chemical and biological signals generated at the tissue level (such as in the interstitial fluid). The presence or concentration of chemical and / or biological analytes can be detected and / or measured. In some examples, the analyte targeted indicates human fertility.

[0017] In addition, the method used herein utilizes an NFC interface. Advantageously, the NFC interface allows the information sensed by the electrochemical sensor to be transmitted transcutaneously, i.e., through the skin barrier. The NFC interface also allows the implantable device to receive power wirelessly from an external source, rather than relying on a battery. The external source can be a mobile phone or other NFC interface, which is arranged to power the implantable device and use NFC to receive data transmitted from the implantable device. The implantable device may include a microcontroller arranged to encrypt data. When the implantable device is fully subcutaneously implanted, the NFC interface is able to receive power transcutaneously, i.e., through the subject's skin, and the NFC interface is also arranged to wirelessly send data transcutaneously.

[0018] The term "chemical sensor" herein also refers to types of electrochemical sensors.

[0019] The implantable device may be based on and / or include a printed circuit board.

[0020] Figure 1 An example printed circuit board 100 is shown. The printed circuit board (PCB) is based on conventional materials such as FR4 and copper. Components of the implantable device can be mounted to the printed circuit board 100, such as at the electronic pads 101, 103. Additional electronic pads 105, 107, 109 are each functionalized as a chemical or electrochemical sensor, as shown below in conjunction with Figure 2 Further described.

[0021] Each electronic pad 101, 103, 105, 107, 109 may have a nickel-gold layer or a simple gold layer deposited thereon, which is arranged to act as a conductive layer. Each electronic pad 101, 103, 105, 107, 109 of the PCB 100 does not apply a solder mask process as is the case with conventional PCBs and other parts of the PCB. Instead, gold and / or nickel is simply applied to the exposed copper of the PCB 100.

[0022] The components of the implantable device that can be mounted to the printed circuit board 100 include an NFC tag, an NFC antenna, a microcontroller, at least one amplifier, and at least one resistor. Each component will be further explained in conjunction with the further examples below. Any component can be mounted on either side of the PCB. In some examples, only one side of the PCB can be used in this way, while in other examples, both sides of the PCB can be used in this way.

[0023] PCB 100 also features conductive traces 111 that are covered by a standard solder mask (screen printing) process. As will be appreciated, Figure 1 Conductive traces 111, not shown in the figure, allow different components to be connected across the PCB. The copper traces may have a width of 0.1 mm. The PCB may also include copper pools and copper plated through holes.

[0024] Figure 2 A cross section of a portion of an implantable device is shown. Figure 1 The printed circuit board 100 is as follows Figure 2 , and has an exemplary thickness of 1000 μm. The electronic pad 200 includes a nickel layer 202 having an exemplary thickness of 6 μm and a gold layer 204 having an exemplary thickness of 2 μm, which is arranged on top of the PCB. The electronic pad can be formed on top of the copper exposed area of ​​the PCB by a technique such as electroplating. The nickel layer is arranged on top of the copper of the PCB, and the gold layer is arranged on top of the nickel layer. In other examples, the nickel layer can be omitted, or layers of different thicknesses or in a different order can be used.

[0025] The chemical sensor 250 is formed on the electronic pad. The chemical sensor includes four layers: nanoparticles 252, an inner barrier layer 254, an immobilized sensing membrane or receptor 256, and a diffusion membrane 258. Thus, the electronic pad is "functionalized" as a chemical sensor for sensing an analyte, such as Figure 1 As shown in the electronic pads 105, 107, and 109. Figure 2 The pads used to connect electronic components (such as amplifiers) to the PCB are not shown. These pads may also have pads arranged in a manner such as Figure 2 Nickel and gold layers on top of them are shown. The mixture and thickness of the gold and nickel layers dictate how good the electrical connection is to the functionalized sensing layer placed on top.

[0026] The diffusion membrane 258 of the chemical sensor 250 allows the analyte to diffuse into the sensor. The analyte diffuses through the diffusion membrane 258 layer and is held at the immobilized sensing membrane 256. Here, the analyte interacts with the chemical sensor 250, causing an electrical change or signal to be generated. The presence of the nanoparticles 252 enhances the electrical signal.

[0027] In each example, the functionalized chemical sensor can be used as an electrode in a sensing and / or measuring circuit, where the "electrode" has been functionalized by an electrochemical process to deposit a specific sensor layer (as previously described) to respond to a chemical analyte. The chemical sensor can be formed to target or sense a specific chemical and / or biological analyte, such as pH, sodium, calcium, potassium, lactate, glucose, cortisol, estrogen, progesterone and / or luteinizing hormone (LH).

[0028] The materials and thicknesses of the various layers of the functionalized chemical sensor are selected to achieve optimal sensitivity to the target chemical analyte. Example materials are shown in Table 1. For example, to detect pH, the diffusion membrane material can be chitosan, the immobilized sensing membrane (receptor material) can be iridium oxide nanoparticles, and so on.

[0029] Table 1

[0030]

[0031]

[0032] The use of nanoparticles 252 as components of the sensing layer significantly improves the sensitivity of electrochemical sensors. Nanoparticles are used for electrode surface modification, signal molecule labeling (specific target binding) and signal amplification and are also used as catalysts for ongoing chemical reactions. Nanoparticles also provide good biocompatibility and higher surface active areas on the electrode, thereby improving the ability of the electrode to transfer electrons, immobilizing bioactive substances on the electrode surface and shortening the detection time. The nanoparticles 252 to be used can have different sizes (in the nanometer range), shapes (spherical, cylindrical, flat, etc.), and can be made of precious metal nanomaterials (such as gold and silver), semiconductor materials (quantum dots), carbon nanomaterials (carbon nanotubes), graphene oxide and composite nanomaterials. Therefore, there are a variety of methods for depositing nanoparticles depending on the type of nanomaterial used and the substrate surface to which they are attached. Examples include dip coating, spin coating, solvent evaporation, chemical vapor deposition and transfer printing.

[0033] In some examples, nanoparticles 252 may be omitted and chemical sensor 250 may include three layers: an inner selective layer, a middle sensing layer, and an outer biocompatible layer.

[0034] Figure 3 300 is shown in cross section. The implantable device 300 is based on a PCB 310, such as Figure 1 and Figure 2 PCB 100. Figure 1 and Figure 2 As shown, chemical sensor 312 is formed on the electronic pads of the PCB. Electronic components 320, 330, 340, 350 (such as amplifiers, resistors and / or NFC tags) are also mounted on the electronic pads of the PCB.

[0035] The implantable device 300 is characterized by an outer layer of a package 360. The package 360 ​​is made of a biocompatible material and ensures that the implantable device 300 is not rejected by the subject's body and remains functional. The package 360 ​​is provided with micropores to allow one or more chemical sensors to access the physiological medium. The micropores can be produced by laser patterning of the package 360 ​​or an alternative suitable technique.

[0036] Implantable device 300 also includes NFC antenna 370. In an example, NFC antenna 370 is wrapped around PCB 310.

[0037] NFC technology allows energy transfer between an implantable device and an NFC-enabled external device that is in close enough range. Therefore, no wiring, batteries, and separate electronics units are required to power the implantable device. Instead, the NFC antenna 370 draws power or energy from the incident field.

[0038] Any device equipped with an NFC chip can power the implantable device. Preferably, encryption is used to prevent unauthorized devices from accessing the data in the device.

[0039] Despite Figure 3 In the example of FIG, only one chemical sensor 312 is shown, but in other examples, the implantable device may feature multiple chemical sensors. Each of the multiple chemical sensors may be of the same type or of a different type. For example, one chemical sensor may be arranged to perform amperometry, and another chemical sensor may be arranged to perform voltammetry. Thus, the implantable device is capable of performing both amperometry and voltammetry techniques, and is also capable of performing both techniques simultaneously. The implantable device may also be arranged to perform impedance-based detection of an analyte.

[0040] Using such a device, two or more different analytes can be measured at one time. Examples of analytes that the devices and apparatus disclosed herein can measure are as follows: pH, sodium, calcium, potassium, lactate, luteinizing hormone, glucose, cortisol, estrogen, and progesterone. In an example where the implantable device is arranged to perform amperometry and voltammetry, the analyte can be arranged to simultaneously sense at least one of pH, sodium, calcium, potassium (using voltammetry); and one of lactate, glucose, and cortisol.

[0041] Figure 4 An example implantation of an implantable device disclosed herein is shown. Figure 4 400 is a scanning electron microscope (SEM) image of such an implantable device. A PCB 402 is shown, which features mounted electronic components. An NFC antenna 404 is also shown, which is formed by a copper wire wrapped around the periphery of the PCB in 20 loops. As a comparison, an encapsulation layer 406 is also shown. In this example, the encapsulation layer includes polymethylsiloxane (PDMS, 1 mm thick) and polyparaxylene (100 μm thick). Both materials are biocompatible. In other examples, other biocompatible materials can be used for the encapsulation layer. Advantageously, the encapsulation layer 406 protects the internal components of the implantable device and extends the life of the device.

[0042] For example, the implantable device may be based on a PCB having a surface area of ​​3.7 mm by 6.5 mm. In some examples, the implantable device may be injected into the target tissue through a needle, thereby alleviating some technical limitations imposed by medical surgical methods.

[0043] Figure 5 A schematic diagram of an electronic circuit 500 for an implantable device is shown. The electronic circuit 500 is suitable for implementation on or with a PCB-based implantable device disclosed herein.

[0044] The electronic circuit 500 includes a microcontroller 501. The microcontroller is arranged to control other components of the electronic circuit 500 and process information to communicate accordingly. For example, the microcontroller is arranged to interact with an NFC tag 503. The NFC tag 503 is arranged to send data using the NFC communication protocol, and the microcontroller can be used to encrypt the data. The NFC tag 503 forms an NFC interface together with an NFC antenna 505. The NFC antenna 505 allows the circuit 500 to receive power wirelessly from an external source. In other words, there is no active power source (such as a battery) in the electronic circuit 500, and it can be considered as a passive circuit in this respect.

[0045] The electronic circuit 500 is arranged to perform voltammetry using a first voltammetry working electrode 507 and a second voltammetry working electrode 509. The voltammetry working electrodes may be functionalized as one or more chemical sensors as described herein, such as Figure 2 The voltammetric portion of the electronic circuit 500 also includes a first amplifier 511 and a second amplifier 513 for each voltammetric working electrode 507, 509. The amplifiers can be mounted on a PCB as described herein. As will be appreciated by those skilled in the art, each amplifier 511, 513 is connected to a resistor assembly 515, 517, 519, 521 of appropriate value and is arranged to amplify the electrical signal generated by the working electrode 507, 509. Commercial off-the-shelf dual amplifiers can be used for amplifiers 511, 513.

[0046] The electronic circuit 500 is also arranged to perform amperometry, and in some examples can perform amperometry simultaneously with voltammetry. The electronic circuit 500 is arranged to perform amperometry using a first amperometry working electrode 531, a reference electrode 533, and a counter electrode 535. In some examples, the three electrodes 531, 533, 535 can be considered to form a single chemical sensor and can be functionalized as described herein, such as Figure 2 and Figure 3 The first amperometric working electrode is connected to an amplifier 537, to which a resistor 538 is also connected. The reference electrode 533 and the counter electrode 535 are connected to another amplifier 539. Commercial off-the-shelf dual amplifiers can be used for amplifiers 537, 539. The amplifiers 537, 539 are arranged to amplify the electrical signals generated by one or more electrodes.

[0047] Return to reference Figure 3 In some examples, the chemical sensor 312 can be arranged to be divided into different "electrodes" corresponding to the electrodes of the electronic circuit 500. For example, the chemical sensor can be arranged to provide three electrodes for amperometry, as described above with respect to the electronic circuit 500: a first amperometry working electrode 531, a reference electrode 533, and a counter electrode 535. A similar arrangement can be used for voltammetry with the same chemical sensor or additional chemical sensors. In such an example, the package 360 ​​correspondingly has a microporous structure so that different "electrodes" of the chemical sensor 312 can access the interstitial fluid and / or tissue being sensed.

[0048] In some examples, reference electrode 533 and counter electrode 535 can be used in conjunction with voltammetric electrodes to generate a signal based on the presence of an analyte.

[0049] Figure 5The electronic circuit 500 shown is capable of measuring up to three chemical analytes simultaneously. One acquisition channel is installed using the above-described amperometric circuit topology (targeting, for example, lactate or glucose, cortisol, etc.), and the other two acquisition channels are installed on the above-described voltammetric circuit topology (targeting, for example, pH or sodium, potassium, calcium, etc.). Each acquisition channel is connected to a separate working electrode, with the counter electrode and reference electrode shared by the three acquisition channels. Each acquisition channel can be described as an ion-sensitive channel.

[0050] The electronic circuit 500 is arranged to amplify and convert the voltage and / or current signals from the channel into digital samples for acquisition by the embedded microcontroller before secure wireless transmission using the NFC protocol.

[0051] As will be appreciated, the components of the electronic circuit 500 may vary. Importantly, the electronic circuit 500 uses a chemical sensor arranged on an electrode to perform voltammetry and / or amperometry of an analyte and then transmits the measured data using NFC. The electronic circuit 500 may alternatively or additionally be arranged to perform impedance detection of at least one analyte.

[0052] In certain examples, the electronic circuit 500 can sense any pair combination of voltammetric (pH, sodium, calcium, potassium, etc.) and amperometric (lactate, glucose, cortisol, etc.) analytes, provided that the electrodes are chemically functionalized to respond to such stimuli.

[0053] In some examples, miniaturization of sensors means that different sensing components can sense the same or different analytes.

[0054] The electronic circuit 500 is also arranged to implement cross-checks between sensors. The metrics for signal amplitude, interference and drift are defined in the programming code running inside the microcontroller. Deviations from typical calibration curves for each single analyte and the effects of external factors (such as temperature) are also recorded and can be sent wirelessly to the user.

[0055] Figure 6 An example of an NFC data communication packet 600 suitable for sending data through an NFC interface of an implantable device disclosed herein is shown. An NFC tag of the NFC interface may be used to send or receive data, and an NFC antenna of the NFC interface may be used to receive power.

[0056] The NFC interface is arranged to interface with a device such as a tablet or mobile phone for power acquisition and data communication.

[0057] The NFC data communication packet 600 includes a preamble 601 , a data stream 602 , and an integrity check field 605 .

[0058] Preamble 601 includes a general data preamble, which is used as a handshake protocol between the two entities involved in the communication. Data stream 602 includes the payload or appropriate data being sent. The data stream 602 field can be 1 kB in plain format or encrypted. Figure 7 As discussed in the example of , the payload can be encrypted within the microcontroller, so it cannot be decoded unless other NFC receivers know the decoding password. Only the data preamble 601 is completely transparent between NFC entities.

[0059] The integrity check field 605 is a 16-bit cyclic redundancy check to prevent the transmission and reception of corrupted data packets.

[0060] The fact that the NFC protocol generates radio frequency signals to send communication packets means that the energy released by this process can be used for wireless charging (energy harvesting) by other nearby NFC devices. The implantable device itself can be powered in this way. The NFC antenna of the implantable device disclosed herein is arranged so that the implantable device can harvest sufficient wireless energy from the RF field generated by the mobile phone at a gap distance of up to 2 cm.

[0061] In some examples, the NFC communication capabilities of the NFC interface are based on standard communication protocols established for NFC (ISO / IEC 14443 and ISO / IEC 18000-3), so any external device that complies with the standards can power the implantable device.

[0062] The NFC communication protocol allows implantable devices to transmit larger amounts of data in a single transmission packet than RFID communication. Using NFC, 1kB of physiological data can be exchanged with an external device each time, while current RFID technology can only transmit a few dozen bytes, with half of each byte used to send the chip identification number and signal communication flag over the air. In addition, the radio frequency power intensity allocated to RFID technology is lower than NFC, which means that the communication distance between the implantable device and the external device is smaller.

[0063] Figure 7 An example method 700 is shown for encrypting data, such as measurement data provided by a chemical sensor. The encrypted data is then provided for transmission using an NFC interface. The method 700 for encrypting data is a lightweight algorithm, i.e., it is intended to be implemented with low power on an implantable device disclosed herein. The method 700 provides that data sent by an NFC tag of an implantable device can only be decoded by an authorized external device. In some examples, the authorized external device can be equipped with a synchronized application.

[0064] The method 700 is divided into three consecutive protection layers and produces approximately 2 to the power of 45 code combinations.

[0065] At a first step 701, the method includes encrypting data with a session password step: an XOR operation between an 8-bit fixed password variable shared by the implantable device and an authorized external device (in some examples, by a synchronization application on a mobile phone) and a one-time random password variable generated by the implantable device in each NFC transmission. The "sync" application shares the same fixed password with the implantable device, enabling it to decipher the encrypted data sent by the implantable device. In some embodiments, only a single implantable device and a single application share a unique fixed password. The fixed password is hard-coded once into the non-volatile memory of the implantable device (inside the microcontroller) during device programming at the manufacturing stage, and is also hard-coded into the programming code of the application before installation in the selected external device, thereby "synchronizing" with the implantable device. A certified technician can install the "sync" application in a single external device using a specification table and software template, and then destroy the table and software template to prevent its use on other external devices. Therefore, similar applications that do not share the same fixed password with a specific implantable device are "out of sync" and cannot decode data from the implantable device.

[0066] At a second step 702, the method includes encrypting the data via a lookup table (LUT) entry. The second step 702 includes an XOR operation between a single 16-bit pattern contained within the LUT, which contains 64 different pattern entries. The LUT is hard-coded into the non-volatile memory of the implantable device and the synchronization application, and is unique to each implantable device. The specific LUT entries of the 64 different entries used during encryption of the implantable device are recovered by the "sync" application by manipulating the bit stream encoded by the combination of the fixed password and the session password portion. The number of entries 64 is used as an example of an exemplary non-volatile memory capacity based on an implantable device microcontroller. In this example, the 64 entries occupy (2^6*x16-bit / 8)=128 bytes or 128 address locations. In other examples, fewer or more numbers of entries may be used depending on the available memory capacity.

[0067] At the third step 705, the method includes NFC memory address hopping. The third step 705 includes randomly assigning data bit blocks to non-contiguous sequential address blocks within the NFC tag before transmission. A single communication channel is used, and the entire data stream is divided into bit blocks, which are assigned to different random address locations within the NFC tag memory, thereby destroying the continuity of the data stream in each transmission. The original continuous stream can only be put together by a synchronized external device.

[0068] Figure 8 A method 800 of sensing an analyte is shown, which method may be performed using the implantable devices and apparatus disclosed herein when fully subcutaneously implanted, such as Figure 2-Figure 7 .

[0069] At a first step 801 , the method includes sensing at least one analyte using an electrochemical sensor.

[0070] At a second step 803 , the method includes transmitting information sensed by the electrochemical sensor using the NFC interface.

[0071] As described above with respect to placement of an implantable device, the method may also include sensing more than one analyte simultaneously using the electrochemical sensor.

[0072] As described above with respect to placement of the implantable device, the method may further include performing voltammetry and amperometry simultaneously.

[0073] As described above with respect to placement of the implantable device, the method may further include sensing at least one of pH, sodium, calcium potassium, lactate, luteinizing hormone, glucose, Cortisol, estrogen, and progesterone.

[0074] As described above with respect to placement of the implantable device, the method may further include simultaneously sensing one of: pH, sodium, calcium, potassium, and one of: lactate, glucose, cortisol.

[0075] As described above with respect to placement of the implantable device, the method may further include harvesting power from the electromagnetic field using the NFC interface.

[0076] As described above with respect to placement of the implantable device, the method may further include sensing at least one analyte indicative of human fertility.

[0077] As described above with respect to the placement of the implantable device, the method may also include encrypting the information sensed by the electrochemical sensor prior to transcutaneous communication. Figure 7 The method 700 performs encryption.

Claims

1. A device arranged to be implanted completely subcutaneously, the device comprising: an electrochemical sensor for sensing at least one analyte, and A near field communication (NFC) interface is used for transmitting the information sensed by the electrochemical sensor transcutaneously.

2. The device of claim 1, wherein the electrochemical sensor is arranged to sense more than one analyte simultaneously.

3. The device of any of the preceding claims, wherein the NFC interface is a passive component.

4. The device according to any of the preceding claims, wherein the electrochemical sensor comprises a selection layer, a sensing layer and an outer biocompatible layer.

5. The device according to any of the preceding claims, wherein the electrochemical sensor is arranged on a pad of a printed circuit board.

6. The device of claim 5, wherein the pads of the printed circuit board are not covered by any solder mask.

7. The device of claim 5 or 6, wherein the pad comprises a contact layer comprising gold. The device of claim 7 , wherein the contact layer further comprises nickel.

9. The device according to any one of the preceding claims, wherein the electrochemical sensor is arranged to perform voltammetry and amperometry simultaneously.

10. A device according to any preceding claim, wherein the device is arranged to perform impedance detection of the at least one analyte.

11. The device according to any one of the preceding claims, wherein the electrochemical sensor is arranged to sense at least one of pH, sodium, calcium, potassium, lactate, luteinizing hormone, glucose, Cortisol, estrogen and progesterone.

12. A device according to any preceding claim, wherein the electrochemical sensor is arranged to simultaneously sense one of: pH, sodium, calcium, potassium; and One of the following: lactate, glucose, cortisol.

13. An apparatus according to any preceding claim, wherein the NFC interface is arranged to derive power from an electromagnetic field.

14. The device of any preceding claim, wherein the device does not comprise a battery.

15. The device according to any of the preceding claims, wherein the electrochemical sensor is arranged to sense at least one analyte indicative of human fertility.

16. An apparatus according to any preceding claim, further comprising an amplifier arranged to amplify a signal generated by the electrochemical sensor.

17. A device according to any preceding claim, arranged to encrypt information sensed by the electrochemical sensor prior to the transcutaneous communication.

18. A method of sensing an analyte, the method being performed in a device as claimed in any one of the preceding claims when the device is fully subcutaneously implanted, the method comprising: sensing at least one analyte using the electrochemical sensor; as well as Information sensed by the electrochemical sensor is transmitted using the NFC interface.

19. The method of claim 18, further comprising using the electrochemical sensor to simultaneously sense more than one analyte.

20. The method of claim 18 or 19, further comprising performing voltammetry and amperometry simultaneously.

21. The method of any one of claims 18 to 20, further comprising sensing at least one of pH, sodium, calcium, potassium, lactate, luteinizing hormone, glucose, Cortisol, estrogen, and progesterone.

22. The method according to any one of claims 18 to 21, further comprising simultaneously sensing: One of the following: pH, sodium, calcium, potassium; and One of the following: lactate, glucose, cortisol.

23. The method of any one of claims 18 to 22, further comprising harvesting power from an electromagnetic field using the NFC interface.

24. The method of any one of claims 18 to 23, further comprising sensing at least one analyte indicative of human fertility.

25. The method of any one of claims 18 to 24, further comprising encrypting information sensed by the electrochemical sensor prior to the transcutaneous communication.

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