Patent Description:
A wide variety of implant devices exist today for various applications and uses. For example, an endoscopic capsule may be implanted to perform telemetry within the gastrointestinal tract of a patient. As another example, a brain-computer interface may be implanted to augment and/or repair various cognitive and sensory-motor functions. As a still further example, implanted micro sensors may be utilized for sensing physiological parameters of an individual. These and other implant devices may include various subsystems for collecting data, providing outputs based on collected data, performing calculations, and/or carrying out various instructions.

Implant devices are often small in size and/or include integrated components. Therefore, accessing, replacing, and/or rearranging the internal components of an implant device can be challenging or prohibitive. For example, it may be difficult to replace or rearrange components because some of the internal components are encapsulated with sealant at the time of manufacture. As another example, altering or changing internal components may be difficult because the handling of the components requires complex, expensive equipment and/or techniques that may not be available or known to those other than the manufacturer. As a result, the internal components of implant devices, including the battery, are typically fully assembled and wired at the time of manufacture, and not subject to change or replacement thereafter.

The battery of an implant device can begin draining after manufacture and assembly of the device. In cases where the battery is not readily accessible or changeable, it is necessary to maximize the shelf life of the battery and operational use of the implant device. Therefore, the amount of power consumed by the internal components prior to use of the implant device needs to be minimized.

One method of reducing the amount of power consumed prior to use of the device is to deactivate a portion of the implant device during storage and activate the portion of the implant device shortly before use. For example, an implant device may be configured to detect unpacking of the package containing the implant device and activate the supply of power from the battery only after detecting the unpacking of the package. However, this approach requires additional components to detect the unpacking of the device (such as a magnet and reed relay) and can increase the overall unit cost of the implant device.

Another approach for restricting the amount of power consumption is to deactivate a portion of the implant device during storage and periodically activate the portion of the implant device to detect whether the implant device has been implanted. While this method may eliminate the need for additional components to detect unpacking, power from the battery is still consumed each time the portion of the implant device is activated. Therefore, this approach may require a larger and more expensive battery to provide a sufficient power source for periodically activating the implant device and for subsequent use after unpacking. As a result, it may not be suitable for many applications. <CIT> discloses a method including detecting an electrical connection with an analyte sensor, and activating a data processing device to receive one or more analyte-related signals from the analyte sensor.

Accordingly, existing systems and methods for activating an implant device do not address the challenge of minimizing the number of components and prolonging shelf life of the device, without increasing the power requirements of the battery or overall expense of the device.

The present disclosure generally relates to systems and methods for activating a circuit of an implant device. Embodiments of the present disclosure include systems and methods that are capable of activating a circuit of an implant device upon electrical coupling of a sensor to the device.

An implant device according to an aspect of the invention is set out in claim <NUM>.

Further optional features are set out in the dependent claims.

The implant device includes a sensor interface configured to interface with a sensor, and a sensing circuit that measures at least one physiological parameter of an individual. The implant device further includes a sensor detector configured to detect whether the sensor is interfacing with the sensor interface and activate the sensing circuit based on the detection.

In accordance with another example embodiment, a method is provided for activating a sensing circuit of an implant device for measuring at least one physiological parameter of an individual. The method includes providing a sensor interface that is configured to interface with a sensor, detecting whether the sensor is interfacing with the sensor interface, and activating the sensing circuit based on the detection of whether the sensor interfacing with the sensor interface.

Before explaining example embodiments of the present disclosure in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The disclosure is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as in the abstract, are for the purpose of description and should not be regarded as limiting.

The accompanying drawings, which are incorporated in and constitute part of this specification, and together with the description, illustrate and serve to explain the principles of various examples and embodiments.

Embodiments of the present disclosure provide improved systems and methods for activating a portion of an implant device with power from a battery by detecting that the implant device is implanted in the body of a subject. The disclosed embodiments are capable of detecting that an implant device is implanted in the body of a subject, while minimizing the number of required components and the amount of power used for detecting the implantation.

Reference will now be made in detail to the embodiments implemented according to the disclosure, the examples of which are illustrated in the accompanying drawings.

<FIG> depicts an example system environment <NUM> for implementing embodiments of the present disclosure. As shown in <FIG>, system environment <NUM> includes an implant device <NUM>. In some embodiments, implant device <NUM> is positioned in a subject <NUM>. Subject <NUM> may be a human subject as shown in <FIG>. Alternatively, subject <NUM> may be an animal subject or any other type of living subject. The size and dimensions of implant device <NUM> may be vary depending on the needs or particular use(s) of the device. In some embodiments, implant device <NUM> may be a centimeter implanted device (i.e., a device having size dimensions at least one centimeter each), a millimeter implanted device (i.e., a device having size dimensions less than one centimeter but at least one millimeter each), or a sub-millimeter implanted device (i.e., a device having size dimensions less than one millimeter each).

Implant device <NUM> may be capable of being implanted at various locations and at various depths within the body of subject <NUM>. While implant device <NUM> is shown in <FIG> as being implanted in the arm of subject <NUM>, other implant locations are contemplated and the illustrated example is in no way intended to be limiting on the embodiments of the present disclosure.

Implanted device <NUM> may measure various parameters of subject <NUM>. In some embodiments, implant device <NUM> may include a system for continuously measuring the glucose level of subject <NUM>. In some embodiments, implant device <NUM> may further include one or more subsystems for sensing the glucose level and/or other parameter(s) of subject <NUM>, providing the measured data to an external monitoring system, and/or storing the measured data. In some embodiments, implant device <NUM> may further include a subsystem for interacting with another implanted device. For example, implant device <NUM> may include a subsystem for providing the measured glucose level to another device (implanted and/or external) that delivers insulin to subject <NUM>. Other example subsystems may be used in conjunction with the disclosed embodiments, however, and the enumerated examples are in no way intended to be limiting on the scope of the present disclosure.

<FIG> is a cross-sectional view of an implant device <NUM> according to a non-claimed example. As shown in <FIG>, implant device <NUM> includes a number of components. It will be appreciated from the present disclosure that the number and arrangement of these components is exemplary only and provided for purposes of illustration. Other arrangements and numbers of components may be utilized.

As shown in <FIG>, implant device <NUM> includes a battery <NUM>, a microchip <NUM>, and a sensor <NUM>, which are mounted on a substrate or circuit board <NUM>. In some examples, one or more of battery <NUM>, microchip <NUM>, and sensor <NUM> may be inside or partially inside circuit board <NUM>. Further, in some examples, circuit board <NUM> may include interconnect <NUM> and interconnect <NUM> that electrically interconnect battery <NUM> to microchip <NUM> and microchip <NUM> to sensor <NUM>, respectively. Interconnects <NUM> and <NUM> may be implemented using copper or another suitable metal layer for interconnecting the components of implant device <NUM>.

In some examples, sensor <NUM> may be implemented as an electrochemical sensor. Electrochemical sensors operate by reacting with the stimuli of interest (i.e., "analyte") and producing an electrical signal proportional to the concentration of the analyte. The analyte may react at the surfaces of a working electrode (WE) and/or a counter electrode (CE) involving either an oxidation and/or reduction mechanism. These reactions may be catalyzed by the electrode materials specifically developed for the analyte.

In some examples, when sensor <NUM> becomes in contact with the analyte for the first time (e.g., when the sensor is first implanted in the body of subject <NUM>), a large, amperometric current may be initially drawn or generated at the WE and CE of the sensor, for example, due to instantaneous reduction of oxygen at the surface of the CE and/or oxidation at the surface of the WE. As the electrochemical reactions continue, however, the amperometric current decreases to a steady-state range that is approximately proportional to the analyte concentration at the electrodes.

Microchip <NUM> may be, for example, an application-specific integrated circuit (ASIC) or any other component(s) containing electronic circuits (e.g., discrete circuit elements and field-programmable gate array (FPGA)). In some examples, implant device <NUM> may further include sealant <NUM> encapsulating battery <NUM> and/or microchip <NUM> so as to prevent the components from becoming in direct contact with the body of subject <NUM>. In some examples, sealant <NUM> may be a hermetic sealant. In some examples, microchip <NUM> may include a plurality of chips.

A portion of microchip <NUM> may be deactivated before implant device <NUM> is implanted in the body of subject <NUM> to maximize the shelf life of implant device <NUM>. In one example, the portion comprises one or more circuit components of microchip <NUM> that are deactivated by preventing power from being supplied to them while microchip <NUM> is stored or not used. The deactivated portion of microchip <NUM> may be activated after detecting that implant device <NUM> has been implanted in the body of subject <NUM>. In some examples, microchip <NUM> may be configured to detect the implantation of implant device <NUM> in the body of subject <NUM> by, for example, including a circuit to detect the large, initial, amperometric current generated at the CE of electrochemical sensor <NUM> immediately after sensor <NUM> first comes into contact with the body of subject <NUM>.

<FIG> is a graph <NUM> showing a transient response of example electrochemical sensor <NUM> of <FIG>, consistent with embodiments of the present disclosure. The dependent variable (y-axis) of graph <NUM> is the amount of current drawn/generated by sensor <NUM>, for example, in nano-amps, and the independent variable (x-axis) of graph <NUM> is time, for example, in seconds.

At time t<NUM>, implant device <NUM> including sensor <NUM> is implanted in the body of subject <NUM>. Thus, the time period before t<NUM> represents a period before implant device <NUM> is implanted in the body of subject <NUM>. Before t<NUM>, sensor <NUM> may generate no current or a negligible amount of current. Immediately after t<NUM> (i.e., immediately after implantation), however, sensor <NUM> may generate a large, initial, amperometric current. In the example of <FIG>, electrochemical sensor <NUM> generates over <NUM> nA immediately after implant device <NUM> is implanted in the body of subject <NUM>.

At time t<NUM>, which is at a predetermined amount time after t<NUM>, the current generated by sensor <NUM> may decrease to a steady-state range. In the example of <FIG>, t<NUM> may be <NUM> seconds after t<NUM>, and the steady-state current range may be between <NUM> nA and <NUM> nA, for example. After t<NUM>, the current drawn/generated by sensor <NUM> may be proportional to the analyte concentration (e.g., glucose concentration). A skilled artesian may experimentally determine time t<NUM> for a given sensor, for example, based on a graph similar to graph <NUM>.

<FIG> is a block diagram illustrating a portion of example implant device <NUM> shown in <FIG>. In <FIG>, electrochemical sensor <NUM> of implant device <NUM> includes a working electrode (WE) connected to a WE node 240A and a counter-electrode (CE) connected to a CE node 240B. In some examples, electrochemical sensor <NUM> may further include a reference electrode (RE).

In <FIG>, microchip <NUM> may include a sensing circuit <NUM> for measuring one or more physiological parameter of an individual and an implantation detector circuit <NUM> for detecting implantation of the implant device in a body of the individual. In the example implant device <NUM> of <FIG>, sensing circuit <NUM> and implantation detection circuit <NUM> both use a single or common sensor (e.g., electrochemical sensor <NUM>) for measuring one or more physiological parameters of the individual and for detecting implantation of the implant device in the body of the individual.

In alternative examples, implant device <NUM> may include a first sensor for detecting implantation of implant device <NUM> in a body of an individual and a second sensor for measuring one or more physiological parameter of the individual. In these examples, sensing circuit <NUM> may measure one or more physiological parameters of the individual using the first sensor and implantation detection circuit <NUM> may use the second sensor to detect implantation of the implant device in a body of the individual. In these examples, the first and second sensors may be different type of sensors. For example, the second sensor may be an electrochemical sensor configured to detect one type of physiological parameter(s), while the first sensor is another electrochemical sensor configured to detect another type of physiological parameter(s).

In some examples, sensing circuit <NUM> may measure one or more physiological parameters of the individual using both the first and second sensors. For example, the first and second sensors may be configured to measure the same physiological parameters, and sensing circuit <NUM> may obtain a more accurate measurement by using both sensors compared to an examples using a single circuit. In another example, the first and second sensors may be configured to measure different physiological parameters, and sensing circuit <NUM> may measure a plurality of physiological parameters using the first and second sensors.

In some examples, sensing circuit <NUM> may be electrically connected to implantation detector circuit <NUM>, for example, via an interconnect <NUM>. Sensing circuit <NUM> and/or implantation detector circuit <NUM> may be electrically connected to and powered by battery <NUM>. In some examples, microchip <NUM> may include a first chip including sensing circuit <NUM> and a second chip including implantation detector circuit <NUM>.

In some examples, sensing circuit <NUM> may operate in one of at least two modes. In a first mode, sensing circuit <NUM> may be configured to consume zero or substantially zero power from a power source such as battery <NUM>. In <FIG>, for example, sensing circuit <NUM> includes one or more switches <NUM> between one or more portions <NUM> of sensing circuit <NUM> and battery <NUM>. Switches <NUM> may be configured to create an open connection (i.e., preventing current from flowing) between portions <NUM> and battery <NUM> while sensing circuit <NUM> is in the first mode.

In some examples, portions <NUM> of sensing circuit <NUM> may include an analog-to-digital converter (ADC) arranged to convert the amount of current generated at WE node 240A to a digital signal. Additionally, or alternatively, portions <NUM> of sensing circuit <NUM> may include an amplifier (e.g., transimpedence amplifier) for generating a voltage-based signal, or a current-based signal having a larger amplitude compared to the raw signal generated by sensor <NUM>. Furthermore, portions <NUM> of sensing circuit <NUM> may include a circuit that generates a voltage-based or current-based signal having a different output impedance. Portions <NUM> of sensing circuit <NUM> may further include other circuit(s) for accurately measuring the current generated at WE node 240A.

In a second mode, sensing circuit <NUM> may be configured to consume sufficient power necessary to sense the current drawn at WE of sensor <NUM> (i.e. at WE node 240A). For example, in exemplary implant device <NUM> of <FIG>, switches <NUM> may create a closed connection (i.e., allowing current to flow) between portion <NUM> and battery <NUM> while sensing circuit <NUM> is in the second mode. Therefore, the amount of power consumed by sensing circuit <NUM> in the second mode may be greater than the amount of power consumed by sensing circuit in the first mode.

In some examples, the operating mode of sensing circuit <NUM> may be determined based on an electrical signal from implantation detection circuit <NUM>. For example, a first signal from implantation detection circuit <NUM> via interconnect <NUM> may cause sensing circuit <NUM> to operate in the first mode while a second signal from implantation detection circuit <NUM> via interconnect <NUM> may cause sensing circuit <NUM> to operate in the second mode. In this example, interconnect <NUM> may be coupled to switches <NUM> to control the supply of power from battery <NUM> to portions <NUM> of sensing circuit <NUM>.

In some examples, sensing circuit <NUM> may switch between one mode to another mode no more than a predetermined number of times. For example, sensing circuit <NUM> may switch from the first mode to the second mode no more than once, based on an electrical signal from implantation detection circuit <NUM>. In this example, after switching to the second mode, sensing circuit <NUM> may remain in the second mode irrespective of the electrical signal received from implantation detection circuit <NUM>.

It will be appreciated that a circuit element may be a linear or a nonlinear element, such as, but not limited to, a resistor, a capacitor, an inductor, a transistor, a memristor, a diode, a transistor, a switch, a current/voltage source, to provide some examples.

In <FIG>, WE node 240A is shown to be connected to sensing circuit <NUM> only; however, it will be appreciated that WE node 240A may be connected to additional circuits including, for example, a circuit providing a bias voltage between WE node 240A and ground. In one example, the bias voltage between the WE and the CE may be <NUM> V.

Further as noted above, the CE of electrochemical sensor <NUM> may generate a large, initial, amperometric current immediately after electrochemical sensor <NUM> first comes into contact with the body of subject <NUM>. Implantation detection circuit <NUM> may detect such amperometric current. For example, implantation detection circuit <NUM> may include one or more circuit elements arranged to generate a first signal (e.g., at interconnect <NUM>) when zero current or substantially zero current is detected at the CE node 240B and generate a second signal (e.g., at interconnect <NUM>) when current above/below a predetermined, threshold current is detected at the CE node 240B. The threshold current may be set based on the expected initial, amperometric current generated by the electrochemical sensor being used. For example, it will be appreciated by a skilled artisan that the threshold current may be determined by experimentally obtaining a graph of a transient response for the electrochemical sensor being used, similar to graph <NUM> of <FIG>.

<FIG> is a circuit diagram of an example implantation detection circuit <NUM> shown in <FIG>. As disclosed herein, implantation detection circuit <NUM> may generate a first signal before implant device <NUM> is implanted and a second signal after implant device <NUM> is implanted. The generated signal, as noted above, may be used by sensing circuit <NUM> to determine the mode of operation. For example, the first signal generated by implantation detection circuit <NUM> may cause sensing circuit <NUM> to operate in a first mode while a second signal generated by implantation detection circuit <NUM> may cause sensing circuit <NUM> to operate in a second mode.

Example implantation detection circuit <NUM> of <FIG> includes a capacitor <NUM> between CE node 240B and ground. Capacitor <NUM> is also arranged to store charges generated at CE node 240B. Implantation detection circuit <NUM> further includes a switch <NUM> (e.g., a relay) between CE node 240B and ground. In some examples, switch <NUM> may periodically short CE node 240B to ground. For example, switch <NUM> may be configured to close or open in response to a signal generated by a clock circuit <NUM>. The periodic shorting of CE node 240B to ground may periodically drain the charges stored by capacitor <NUM>. Therefore, the average amount of current generated at CE node 240B may determine the maximum amount of charge stored in capacitor <NUM> as well as the maximum voltage between CE node 240B and ground during a single clock cycle.

Example implantation detection circuit <NUM> of <FIG> further includes a threshold detector <NUM> that generates an output signal based on the detected voltage between CE node 240B and ground. For example, threshold detector <NUM> may output a first signal when the voltage between CE node 240B and ground is below a threshold voltage and output a second signal once the voltage between CE node 240B and ground is above (or equal to) the threshold voltage. In some examples, threshold detector <NUM> may continue to generate the second signal even when the voltage between CE node 240B and ground subsequently falls below the threshold voltage.

In some examples, once threshold detector <NUM> detects a voltage that is above the threshold voltage, threshold detector <NUM> may cause switch <NUM> to close permanently thereby permanently shorting the CE node 240B with ground.

In some examples, the first signal and the second signal may be represented by one or more voltage or current levels. For example, the first signal may be represented by the supply voltage of microchip <NUM>, while the second single may be represented by the ground-level voltage.

In some examples, the capacitance of capacitor <NUM> may be between <NUM> nF and 500nF, the frequency of the signal generated by clock circuit <NUM> may be between <NUM> and <NUM>, and/or the threshold voltage of voltage threshold detector <NUM> may be between <NUM> V and <NUM> V.

<FIG> is a non-claimed illustrative process <NUM> for activating a circuit for measuring one or more physiological parameters of an individual. At step <NUM>, a sensor including a WE and a CE is provided. In some examples, the WE of the sensor may be electrically coupled to a sensing circuit. At step <NUM>, a first current is generated at the CE of the sensor in response to implantation of the implant device in a body of the individual. At step <NUM>, the sensing circuit is activated in response to the generation of the first current. In some examples, the activation of the sensing circuit in response to the first current may include generating a clock signal, shorting the CE with ground based on the clock signal, detecting a voltage between the CE of the sensor and ground, and activating the sensing circuit based on the voltage between the CE of the sensor and ground. In some examples, the activation of the sensing circuit may further include providing power from a power source to activate the sensing circuit. In some examples, the power source may be a battery. At step <NUM>, the activated sensing circuit may measure one or more physiological parameters of the individual.

<FIG> is a cross-sectional view of another exemplary implant device <NUM>. As shown in <FIG>, implant device <NUM> includes a battery <NUM> and a microchip <NUM>, which are mounted on a substrate or circuit board <NUM>. Circuit board <NUM> may include interconnect <NUM> that electrically interconnects battery <NUM> to microchip <NUM>. Circuit board <NUM> may also include interconnect <NUM> that is electrically connected to microchip <NUM>.

Microchip <NUM> may be, for example, an ASIC or any other component(s) containing electronic circuits (e.g., discrete circuit elements and FPGA). In some embodiments, implant device <NUM> may further include sealant <NUM> encapsulating battery <NUM> and/or microchip <NUM> so as to prevent the components from becoming in direct contact with the body of subject <NUM>. In some embodiments, sealant <NUM> may be a hermetic sealant. In some embodiments, microchip <NUM> may include a plurality of chips.

<FIG> also shows a sensor <NUM>. However, unlike sensor <NUM> of implant device <NUM> of <FIG>, which may be assembled to substrate <NUM> during the manufacturing process, sensor <NUM> may be separate from implant device <NUM> even after the manufacturing process. In some embodiments, sensor <NUM> and implant device <NUM> may be configured such that sensor <NUM> may be assembled to circuit board <NUM> after the manufacturing process (e.g., by the patient or physician). For example, as shown in <FIG>, implant device <NUM> may include a sensor interface <NUM> that electrically couples sensor <NUM> with microchip <NUM> (via interconnect <NUM>). Further, sensor interface <NUM> may be configured to facilitate electrical coupling of microchip <NUM> with sensor <NUM> after the manufacturing process. For example, sensor interface <NUM> may be an array of exposed I/O pads that can align and bond to an array of solder balls I/Os of sensor <NUM>.

In some embodiments, sensor interface <NUM> may be configured such that sensor <NUM> can be electrically coupled to microchip <NUM> without tools such as soldering tools, alignment tools, and/or reflow heaters. For example, sensor interface <NUM> may be a socket-based or slot-based interface that is compatible with electrical interfaces of sensor <NUM>. These interfaces may be used to electrically couple sensor <NUM> with microchip <NUM> at the user end (e.g., by the patient, physician, or salesperson).

In some embodiments, sensor interface <NUM> may be a re-matable interface where sensor <NUM> can repeatedly de-interface or re-interface with sensor interface <NUM>. Additionally, or alternatively, sensor interface <NUM> may facilitate repeated electrical coupling and decoupling of sensor <NUM> with microchip <NUM>. In some embodiments, sensor interface <NUM> may include a mechanism to hold sensor <NUM> to circuit board <NUM>. For example, sensor interface <NUM> may include a mechanical clamp to hold sensor <NUM> to circuit board <NUM>.

Sensor interface <NUM> may include an electrical interface to facilitate electrical coupling of sensor <NUM> with microchip <NUM> via interconnect <NUM>. In some embodiments, the electrical interface may be a capacitive, resistive, and/or inductive interface.

Sensor <NUM> may be an electrochemical sensor, an inertial sensor, pressure sensor, light sensor, microphone, or any other sensor that can be implanted to subject <NUM>.

A portion of microchip <NUM> may be deactivated while sensor <NUM> is separate from implant device <NUM> (i.e., while sensor <NUM> is electrically decoupled from microchip <NUM> and/or de-interfaced from sensor interface <NUM>) to maximize the shelf life of implant device <NUM>. In one example, the portion comprises one or more circuit components of microchip <NUM> that are deactivated by preventing power from being supplied to them while sensor <NUM> is separate from implant device <NUM>. The deactivated portion of microchip <NUM> may be activated after detecting that sensor <NUM> has interfaced with sensor interface <NUM> and/or electrically coupled to microchip <NUM>.

<FIG> is a block diagram illustrating a portion of example implant device <NUM> shown in <FIG>, consistent with embodiments of the present disclosure. In <FIG>, sensor <NUM> of implant device <NUM> includes a first electrode connected to a first node 740A and a second electrode connected to a second node 740B.

In <FIG>, microchip <NUM> may include a sensing circuit <NUM> for measuring one or more physiological parameter of an individual, and a sensor detector circuit <NUM> for detecting when sensor <NUM> interfaces with sensor interface <NUM> and/or when sensor <NUM> electrically couples with microchip <NUM>. As shown in <FIG>, first node 740A and second node 740B are connected to sensor detection circuit <NUM> and at least first node 740A is connected to sensing circuit <NUM>. In some embodiments, second node 740B may also be connected to sensing circuit <NUM>.

In some embodiments, sensing circuit <NUM> may be electrically connected to sensor detector circuit <NUM>, for example, via an interconnect <NUM>. Sensing circuit <NUM> and/or sensor detector circuit <NUM> may be electrically connected to and powered by battery <NUM>. In some embodiments, microchip <NUM> may include a first chip including sensing circuit <NUM> and a second chip including sensor detector circuit <NUM>.

In some embodiments, portions <NUM> of sensing circuit <NUM> may include an analog-to-digital converter (ADC) arranged to convert the current or voltage levels (or potential) at first node 740A to a digital signal. Additionally, or alternatively, portions <NUM> of sensing circuit <NUM> may include an amplifier (e.g., a transimpedence amplifier) for generating a voltage-based signal, or a current-based signal having a larger amplitude compared to the raw signal sensed at first node 740A. Furthermore, portions <NUM> of sensing circuit <NUM> may include a circuit that generates a voltage-or current-based signal having a different output impedance. Portion <NUM> of sensing circuit <NUM> may further include other circuit(s) for accurately measuring the current or voltage at first node 740A. In some embodiments, portions <NUM> of sensing circuit <NUM> may also connect to second node 740B. In these embodiments, portions <NUM> of sensing circuit <NUM> may further includes circuit(s) for accurately measuring the current or voltage at second node 740B.

In some embodiments, sensing circuit <NUM> may operate in one of at least two modes. In a first mode, sensing circuit <NUM> may be configured to consume zero or substantially zero power from a power source such as battery <NUM>. In <FIG>, for example, sensing circuit <NUM> includes one or more switches <NUM> between one or more portions <NUM> of sensing circuit <NUM> and battery <NUM>. Switches <NUM> may be configured to create an open connection (i.e., preventing current from flowing) between portions <NUM> and battery <NUM> while sensing circuit <NUM> is in the first mode.

In a second mode, sensing circuit <NUM> may be configured to consume a sufficient power necessary to sense the current or voltage at first node 740A (and/or second node 740B). For example, in exemplary implant device <NUM> of <FIG>, switches <NUM> may create a closed connection (i.e., allowing current to flow) between portion <NUM> and battery <NUM> while sensing circuit <NUM> is in the second mode. Therefore, the amount of power consumed by sensing circuit <NUM> in the second mode may be greater than the amount of power consumed by sensing circuit in the first mode.

In some embodiments, the operating mode of sensing circuit <NUM> may be determined based on an electrical signal from sensor detection circuit <NUM>. For example, a first signal from sensor detection circuit <NUM> via interconnect <NUM> may cause sensing circuit <NUM> to operate in the first mode while a second signal from sensor detection circuit <NUM> via interconnect <NUM> may cause sensing circuit <NUM> to operate in the second mode. In this example, interconnect <NUM> may be coupled to switches <NUM> to control the supply of power from battery <NUM> to portions <NUM> of sensing circuit <NUM>.

In some embodiments, while in the first mode and/or second mode, portions <NUM> of sensing circuit <NUM> may be configured to such that an input impedance is high (e.g., similar to an input impedance of an op-amp) so as to maximize the portion of current flowing to sensor detection circuit <NUM>.

In some embodiments, sensor <NUM> may be configured to electrically couple the first and second electrodes. For example, sensor <NUM> may resistively, capacitive, and/or inductively couple the first and second electrodes of sensor <NUM>. In these embodiments, when a signal is present at the second electrode of sensor <NUM>, a corresponding signal that is based on the signal may be generated at the first electrode of sensor <NUM>.

<FIG> is a circuit diagram of an example sensor detection circuit <NUM> shown in <FIG>, consistent with embodiments of the present disclosure. As disclosed herein, sensor detection circuit <NUM> may generate a first signal at interconnect <NUM> when sensor detection circuit <NUM> detects that sensor <NUM> is electrically decoupled from microchip <NUM> and a second signal at interconnect <NUM> when sensor detection circuit <NUM> detects that sensor <NUM> is electrically coupled with microchip <NUM>. The generated signal, as noted above, may be used by sensing circuit <NUM> to determine the mode of operation. For example, the first signal generated by sensor detection circuit <NUM> may cause sensing circuit <NUM> to operate in a first mode while a second signal generated by sensor detection circuit <NUM> may cause sensing circuit <NUM> to operate in a second mode.

As shown in <FIG>, sensor detection circuit <NUM> includes a signal generator <NUM> connected to second node 740B. In some embodiments, signal generator <NUM> may generate a voltage-based or a current based signal at second node 740B. In some embodiments, the signal generated by signal generator <NUM> may be an AC signal (voltage or current). Alternatively, the signal generated by signal generator <NUM> may be a DC voltage or DC current. In some embodiments, the signal generator may be a clock signal generator.

In some embodiments, as shown in <FIG>, sensor detection circuit <NUM> may further include a switch <NUM> between second node 740B and ground. While sensing circuit <NUM> is in the first mode, switch <NUM> may be open such the voltage or current at second node 740B is the signal from signal generator <NUM>. In some embodiments, however, while sensing circuit <NUM> is in the second mode, switch <NUM> may be closed such that second node <NUM> is electrically shorted to ground. That is, while sensing circuit <NUM> is in the second mode, second node 740B may be grounded even when signal generator <NUM> generates a signal. The grounding of second node 740B may increase the accuracy of sensing circuit <NUM>.

As shown in <FIG>, sensor detector circuit <NUM> may also include a signal detector <NUM> connected to first node 740A. Signal detector <NUM> may be configured to sense (or measure) voltage and/or current levels at first node 740A. Further, based on the sensed levels, signal detector <NUM> may generate the first or second signal at interconnect <NUM>. This generated signal, as noted above, may be used by sensing circuit <NUM> to determine the mode of operation.

In some embodiments, the first signal and the second signal may be represented by one or more voltage or current levels. For example, the first signal may be represented by the supply voltage of microchip <NUM>, while the second single may be represented by the ground-level voltage.

As discussed above, in some embodiments, sensor <NUM> may be configured to electrically couple the first and second electrodes. Further as discussed above, in these embodiments, when a signal is present at the second electrode of sensor <NUM>, a corresponding signal that is based on the signal may be generated at the first electrode of sensor <NUM>. In some embodiments, when sensor <NUM> interfaces with sensor interface <NUM>, the first electrode of sensor <NUM> may electrically couple with first node 740A and the second electrode of sensor <NUM> may electrically couple with second node 740B. Therefore, when sensor <NUM> electrically couples to microchip <NUM>, the signal generated by signal generator <NUM> at second node 740B may cause a corresponding signal to be generated at first node 740A (since sensor <NUM> may electrically couple first node 740A with second node 740B).

In some embodiments, sensor detector circuit <NUM> may determine that sensor <NUM> is electrically coupled to microchip <NUM> when the corresponding signal is detected at first node 740A. Further, sensor detector circuit <NUM> may determine that sensor <NUM> is electrically decoupled from microchip <NUM> when the corresponding signal is not detected at first node 740A. In some embodiments, the corresponding signal may be derived from the generated signal. Alternatively, or additionally, the corresponding signal may be substantially the same as the generated signal.

In one example, sensor <NUM> may be configured to capacitively couple the first and second electrodes of sensor <NUM>. And, when sensor <NUM> interfaces with sensor interface <NUM>, the first electrode of sensor <NUM> may electrically couple with first node 740A and the second electrode of sensor <NUM> may electrically couple with the second node 740B. Therefore, in this example, when signal generator <NUM> generates a first AC voltage signal having a first frequency at second node 740B, a second AC voltage signal may be generated at first node 740A since first node 740A and second node 740B are capacitively coupled via sensor <NUM>. Further, the second AC voltage signal may have the same frequency as the first AC voltage signal.

Additionally, sensor detector circuit <NUM> may determine that sensor <NUM> is electrically decoupled with microchip <NUM> when an AC voltage signal having the same frequency is not detected at first node 740A, and determine that sensor <NUM> is electrically coupled with microchip <NUM> when an AC voltage signal having the same frequency is detected at first node 740A.

In some embodiments, sensor detector circuit <NUM> may include a threshold detector that generates an output signal based on the detected voltage or current at first node 740A. For example, the threshold detector of sensor detector circuit <NUM> may output a first signal at interconnect <NUM> when the voltage at first node 740A is below a threshold voltage or current and output a second signal once the voltage at first node 740A is above (or equal to) the threshold voltage.

In one example, sensor <NUM> may be configured to resistively couple the first electrode and the second electrode of sensor <NUM>. Further, signal generator <NUM> may generate a first DC voltage-level (e.g., positive voltage) at second node 740B. When sensor <NUM> is electrically coupled to microchip <NUM>, a second DC voltage level may be generated at first node 740A because first node 740A and second node 740B are resistively coupled via sensor <NUM>. Further, the second DC voltage level may be lower than the first DC voltage level. In this example, the threshold detector of sensor detector circuit <NUM> may determine that sensor <NUM> is electrically decoupled from microchip <NUM> when a voltage level detected at first node 740A is below a threshold voltage, and determine that sensor <NUM> is electrically coupled to microchip <NUM> when a voltage level detected at first node 740A is above the threshold voltage.

In some embodiments, the threshold detector of sensor detector circuit <NUM> may determine that sensor <NUM> is electrically decoupled to microchip <NUM> when a voltage level detected at first node 740A is below a first threshold voltage, and determine that sensor <NUM> is electrically coupled to microchip <NUM> when a voltage level detected at first node 740A is above a second threshold voltage. In these embodiments, the first and second threshold voltages may be different.

<FIG> is an illustrative process <NUM> for activating a sensing circuit of an implant device for measure at least one physiological parameter of an individual using the sensor. At step <NUM>, a sensor interface for interfacing with a sensor is provided. At step <NUM>, a sensor detector may detect whether the sensor is interfacing with the sensor interface. At step <NUM>, the sensor detector may activate the sensing circuit based on the detection of whether the sensor interfacing with the sensor interface.

At an optional step, the sensor interface may interface the sensor. In some embodiments, the interfacing of the sensor interface with the sensor may include mechanically holding the sensor to the implant device. In some embodiments, the interfacing of the sensor interface with the sensor may include electrically coupling the sensor interface with the sensor. In some embodiments, the detection of whether the sensor is interfacing with the sensor interface may include sending a signal to the sensor interface and receiving a corresponding signal from the sensor interface when the sensor is interfacing with the sensor interface. In these embodiments, the corresponding signal is related to the signal. In some embodiments, the signal and the corresponding signal may have the same frequency. At an optional step, a sensing circuit, using the sensor, may measure the at least one physiological parameter of the individual after the interfacing of the sensor interface with the sensor. At an optional step, the sensor may de-interface the sensor interface re-interfacing the sensor interface.

Claim 1:
An implant device (<NUM>, <NUM>) comprising:
a sensor interface (<NUM>) configured to interface with a sensor (<NUM>), wherein the sensor includes a first sensor node and a second sensor node, and the sensor interface includes a first interface node (740B) and a second interface node (740A), the sensor interface being further configured to electrically couple the first sensor node with the first interface node and the second sensor node with the second interface node;
a sensing circuit (<NUM>) that measures at least one physiological parameter of an individual; and
a sensor detector (<NUM>) configured to:
detect whether the sensor is interfacing with the sensor interface; and
activate the sensing circuit based on the detection;
wherein the sensor detector includes:
a signal generator (<NUM>) configured to send a signal to the sensor interface; and
a signal detector (<NUM>) configured to detect a corresponding signal from the sensor interface when the sensor is interfacing with the sensor interface, wherein the corresponding signal is related to the signal.