ELECTROMAGNETIC POWER BIO-MEDICAL UNIT

Abstract

A bio-medical unit includes a power harvesting module, a processing module, memory, and one or more functional modules. The power harvesting module is operable to receive magnetic field energy and convert the magnetic field energy into a supply voltage. The power harvesting module powers the processing module, memory, and the one or more functional modules via the supply voltage.

Description

This patent application is claiming priority under 35 USC §119 to a provisionally filed patent application entitled BIO-MEDICAL UNIT AND APPLICATIONS THEREOF, having a provisional filing date of Sep. 30, 2009, and a provisional Ser. No. 61/247,060.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

NOT APPLICABLE

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

NOT APPLICABLE

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to medical equipment and more particularly to wireless medical equipment.

2. Description of Related Art

As is known, there is a wide variety of medical equipment that aids in the diagnosis, monitoring, and/or treatment of patients' medical conditions. For instances, there are diagnostic medical devices, therapeutic medical devices, life support medical devices, medical monitoring devices, medical laboratory equipment, etc. As specific exampled magnetic resonance imaging (MRI) devices produce images that illustrate the internal structure and function of a body.

The advancement of medical equipment is in step with the advancements of other technologies (e.g., radio frequency identification (RFID), robotics, etc.). Recently, RFID technology has been used for in vitro use to store patient information for easy access. While such in vitro applications have begun, the technical advancement in this area is in its infancy.

Therefore, a need exists for a bio-medical unit and applications thereof.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods of operation that are further described in the following Brief Description of the Drawings, the Detailed Description of the Invention, and the claims. Other features and advantages of the present invention will become apparent from the following detailed description of the invention made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a diagram of an embodiment of a system in accordance with the present invention;

FIG. 2 is a diagram of another embodiment of a system in accordance with the present invention;

FIG. 3 is a diagram of an embodiment of an artificial body part including one or more bio-medical units in accordance with the present invention;

FIG. 4 is a schematic block diagram of an embodiment of an artificial body part in accordance with the present invention;

FIG. 5 is a diagram of another embodiment of a system in accordance with the present invention;

FIG. 6 is a diagram of another embodiment of a system in accordance with the present invention;

FIG. 7 is a diagram of another embodiment of a system in accordance with the present invention;

FIG. 8 is a schematic block diagram of an embodiment of a bio-medical unit in accordance with the present invention;

FIG. 8A is a schematic block diagram of another embodiment of a bio-medical unit in accordance with the present invention;

FIG. 8B is a schematic block diagram of another embodiment of a bio-medical unit in accordance with the present invention;

FIG. 9 is a schematic block diagram of an embodiment of a power harvesting module in accordance with the present invention;

FIG. 10 is a schematic block diagram of another embodiment of a power harvesting module in accordance with the present invention;

FIG. 11 is a schematic block diagram of another embodiment of a power harvesting module in accordance with the present invention;

FIG. 12 is a schematic block diagram of another embodiment of a power harvesting module in accordance with the present invention;

FIG. 13 is a schematic block diagram of an embodiment of a power boost module in accordance with the present invention;

FIG. 13A is a schematic block diagram of an embodiment of a generator in accordance with the present invention;

FIG. 13B is a schematic block diagram of an embodiment of a generator in accordance with the present invention;

FIG. 14 is a schematic block diagram of an embodiment of an electromagnetic (EM)) power harvesting module in accordance with the present invention;

FIG. 15 is a schematic block diagram of another embodiment of an electromagnetic (EM) power harvesting module in accordance with the present invention;

FIG. 15A is a schematic block diagram of an embodiment of a generator in accordance with the present invention;

FIG. 16 is a schematic block diagram of another embodiment of a bio-medical unit in accordance with the present invention;

FIG. 17 is a diagram of another embodiment of a system in accordance with the present invention;

FIG. 18 is a diagram of an example of a communication protocol within a system in accordance with the present invention;

FIG. 19 is a diagram of another embodiment of a system in accordance with the present invention; and

FIG. 20 is a diagram of another example of a communication protocol within a system in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a diagram of an embodiment of a system that includes a plurality of bio-medical units 10 embedded within a body and/or placed on the surface of the body to facilitate diagnosis, treatment, and/or data collections. Each of the bio-medical units 10 is a passive device (e.g., it does not include a power source (e.g., a battery)) and, as such, includes a power harvesting module. The bio-medical units 10 may also include one or more of memory, a processing module, and functional modules.

In operation, a transmitter emits 12 electromagnetic signals 16 that pass through the body and are received by a receiver 14. The transmitter 12 and receiver 14 may be part of a piece of medical diagnostic equipment (e.g., magnetic resonance imaging (MRI), X-ray, etc.) or independent components for stimulating and communicating with the network of bio-medical units in and/or on a body. One or more of the bio-medical units 10 receives the transmitted electromagnetic signals 16 and generates a supply voltage therefrom. Examples of this will be described in greater detail with reference to FIGS. 8-15.

Embedded within the electromagnetic signals 16 (e.g., radio frequency (RF) signals, millimeter wave (MMW) signals, MRI signals, etc.) or via separate signals, the transmitter 12 communicates with one or more of the bio-medical units 10. For example, the electromagnetic signals 16 may have a frequency in the range of a few MHz to 900 MHz and the communication with the bio-medical units 10 is modulated on the electromagnetic signals 16 at a much higher frequency (e.g., 5 GHz to 300 GHz). As another example, the communication with the bio-medical units 10 may occur during gaps (e.g., per protocol of medical equipment or injected for communication) of transmitting the electromagnetic signals 16. As another example, the communication with the bio-medical units 10 occurs in a different frequency band and/or using a different transmission medium (e.g., use RF or MMW signals when the magnetic field of the electromagnetic signals are dominate, use ultrasound signals when the electromagnetic signals 16 are RF and/or MMW signals, etc.).

One or more of the bio-medical units 10 receives the communication signals 18 and processes them accordingly. The communication signals 18 may be instructions to collect data, to transmit collected data, to move the unit's position in the body, to perform a function, to administer a treatment, etc. If the received communication signals 18 require a response, the bio-medical unit 10 prepares an appropriate response and transmits it to the receiver 14 using a similar communication convention used by the transmitter 12.

FIG. 2 is a diagram of another embodiment of a system that includes a plurality of bio-medical units 10 embedded within a body and/or placed on the surface of the body to facilitate diagnosis, treatment, and/or data collections. Each of the bio-medical units 10 is a passive device and, as such, includes a power harvesting module. The bio-medical units 10 may also include one or more of memory, a processing module, and functional modules. In this embodiment, the person is placed in an MRI machine (fixed or portable) that generates a magnetic field 26 through which the MRI transmitter 20 transmits MRI signals 28 to the MRI receiver 22.

One or more of the bio-medical units 10 powers itself by harvesting energy from the magnetic field 26, changes of the magnetic field as produced by gradient coils, from the magnetic fields of the MRI signals 28, from the electrical fields of the MRI signals 28, and/or from the electromagnetic aspects of the MRI signals 28. A unit 10 converts the harvested energy into one or more supply voltages that supplies other components of the unit (e.g., a communication module, a processing module, memory, a functional module, etc.) with power.

A communication device 24 communicates data and/or control communications 30 with one or more of the bio-medical units 10 over one or more wireless links. The communication device 24 may be a separate device from the MRI machine or integrated into the MRI machine. For example, the communication device 24, whether integrated or separate, may be a cellular telephone, a computer with a wireless interface (e.g., a WLAN station and/or access point, Bluetooth, a proprietary protocol, etc.), etc. A wireless link may be one or more frequencies in the ISM band, in the 60 GHz frequency band, the ultrasound frequency band, and/or other frequency bands that supports one or more communication protocols (data modulation schemes, beamforming, RF or MMW modulation, encoding, error correction, etc.).

The composition of the bio-medical units 10 includes non-ferromagnetic materials (e.g., paramagnetic or diamagnetic) and/or metal alloys that are minimally affected by an external magnetic field 26. In this regard, the units harvest power from the MRI signals 28 and communicate using RF and/or MMW electromagnetic signals with negligible chance of encountering the projectile or missile effect of implants that include ferromagnetic materials.

FIG. 3 is a diagram of an embodiment of an artificial body part 32 including one or more bio-medical units 10 that may be surgically implanted into a body. The artificial body part 32 may be a pace maker, a breast implant, a joint replacement, an artificial bone, splints, fastener devices (e.g., screws, plates, pins, sutures, etc.), artificial organ, etc. The artificial body part 32 may be permanently embedded in the body or temporarily embedded into the body.

FIG. 4 is a schematic block diagram of an embodiment of an artificial body part 32 that includes one or more bio-medical units 10. For instance, one bio-medical unit 10 may be used to detect infections, the body's acceptance of the artificial body part 32, measure localized body temperature, monitor performance of the artificial body part 32, and/or data gathering for other diagnostics. Another bio-medical unit 10 may be used for deployment of treatment (e.g., disperse medication, apply electrical stimulus, apply RF radiation, apply laser stimulus, etc.). Yet another bio-medical unit 10 may be used to adjust the position of the artificial body part 32 and/or a setting of the artificial body part 32. For example, a bio-medical unit 10 may be used to mechanically adjust the tension of a splint, screws, etc. As another example, a bio-medical unit 10 may be used to adjust an electrical setting of the artificial body part 32.

FIG. 5 is a diagram of another embodiment of a system that includes a plurality of bio-medical units 10 and one or more communication devices 24 coupled to a wide area network (WAN) communication device 34 (e.g., a cable modem, DSL modem, base station, access point, hot spot, etc.). The WAN communication device 34 is coupled to a network 42 (e.g., cellular telephone network, internet, etc.), which has coupled to it a plurality of remote monitors 36, a plurality of databases 40, and a plurality of computers 38.

In an example of operation, one or more of the remote monitors 36 may receive images and/or other data 30 from one or more of the bio-medical units 10 via the communication device 24, the WAN communication device 34, and the network 42. In this manner, a person(s) operating the remote monitors 36 may view images and/or the data 30 gathered by the bio-medical units 10. This enables a specialist to be consulted without requiring the patient to travel to the specialist's office.

In another example of operation, one or more of the computers 38 may communicate with the bio-medical units 10 via the communication device 24, the WAN communication device 34, and the network 42. In this example, the computer 36 may provide commands 30 to one or more of the bio-medical units 10 to gather data, to dispense a medication, to move to a new position in the body, to perform a mechanical function (e.g., cut, grasp, drill, puncture, stitch, etc.), etc. As such, the bio-medical units 10 may be remotely controlled via one or more of the computers 36.

In another example of operation, one or more of the bio-medical units 10 may read and/or write data from or to one or more of the databases 40. For example, data (e.g., a blood sample analysis) generated by one or more of the bio-medical units 10 may be written to one of the databases 40. The communication device 24 and/or one of the computers 36 may control the writing of data to or the reading of data from the database(s) 40. The data may further include medical records, medical images, prescriptions, etc.

FIG. 6 is a diagram of another embodiment of a system that includes a plurality of bio-medical units 10. In this embodiment, the bio-medical units 10 can communicate data and/or control communications 30 with each other directly and/or communicate with the communication device 24 directly. The communication medium may be an infrared channel(s), an RF channel(s), a MMW channel(s), and ultrasound. The units may use a communication protocol such as token passing, carrier sense, time division multiplexing, code division multiplexing, frequency division multiplexing, etc.

FIG. 7 is a diagram of another embodiment of a system that includes a plurality of bio-medical units 10. In this embodiment, one of the bio-medical units 44 functions as an access point for the other units. As such, the designated unit 44 routes communications 30 between one or more units 10 and the communication device 24. The communication medium may be an infrared channel(s), an RF channel(s), a MMW channel(s), and ultrasound. The units 10 may use a communication protocol such as token passing, carrier sense, time division multiplexing, code division multiplexing, frequency division multiplexing, etc.

FIG. 8 is a schematic block diagram of an embodiment of a bio-medical unit 10 that includes a power harvesting module 46, a communication module 48, a processing module 50, memory 52, and one or more functional modules 54. The power harvesting module 46 may include an energy conversion module 41 and a supply voltage generation circuit 43. The processing module 50 may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. The processing module 50 may have an associated memory 52 and/or memory element, which may be a single memory device, a plurality of memory devices, and/or embedded circuitry of the processing module. Such a memory device 52 may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that if the processing module 50 includes more than one processing device, the processing devices may be centrally located (e.g., directly coupled together via a wired and/or wireless bus structure) or may be distributedly located (e.g., cloud computing via indirect coupling via a local area network and/or a wide area network). Further note that when the processing module 50 implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory and/or memory element storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Still further note that, the memory element stores, and the processing module executes, hard coded and/or operational instructions corresponding to at least some of the steps and/or functions illustrated in FIGS. 1-20.

The power harvesting module 46 may generate one or more supply voltages 56 (Vdd) from magnetic field energy 16, which includes one or more of electromagnetic signals, MRI signals, magnetic fields, RF signals, MMW signals, and body motion. In an embodiment, the energy conversion unit 41 receives varying gradient magnetic fields of magnetic resonance imaging (MRI) signals, wherein the magnetic field energy include the MRI signals. The energy conversion unit 41 induces an alternating current from the varying gradient magnetic fields and converts the alternating current into one or more voltages. The supply voltage generation circuit 43 regulates the one or more voltages to produce the supply voltage 56.

In another embodiment, the energy conversion unit 41 receives radio frequency (RF) transmission burst signals of magnetic resonance imaging (MRI) signals, wherein the magnetic field energy include the MRI signals. The energy conversion unit 41 converts the RF transmission burst signals into one or more voltages. The supply voltage generation circuit 43 regulates the one or more voltages to produce the supply voltage 56.

In other embodiments, the power harvesting module 46 may be implemented as disclosed in U.S. Pat. No. 7,595,732 to generate one or more supply voltages from an RF signal. The power harvesting module 46 may be implemented as shown in one or more FIGS. 9-11 and 13-15 to generate one or more supply voltages 56 from the magnetic field energy 16. The power harvesting module 46 may be implemented as shown in FIG. 12 to generate one or more supply voltage 56 from body motion and/or MRI signals.

The communication module 48 may include a receiver section and a transmitter section. The transmitter section converts an outbound symbol stream into an outbound RF or MMW signal 60 that has a carrier frequency within a given frequency band (e.g., 900 MHz, 2.5 GHz, 5 GHz, 57-66 GHz, etc.). In an embodiment, this may be done by mixing the outbound symbol stream with a local oscillation to produce an up-converted signal. One or more power amplifiers and/or power amplifier drivers amplifies the up-converted signal, which may be RF or MMW bandpass filtered, to produce the outbound RF or MMW signal 60. In another embodiment, the transmitter section includes an oscillator that produces an oscillation. The outbound symbol stream provides phase information (e.g., +/−Δθ [phase shift] and/or θ(t) [phase modulation]) that adjusts the phase of the oscillation to produce a phase adjusted RF or MMW signal, which is transmitted as the outbound RF signal 60. In another embodiment, the outbound symbol stream includes amplitude information (e.g., A(t) [amplitude modulation]), which is used to adjust the amplitude of the phase adjusted RF or MMW signal to produce the outbound RF or MMW signal 60.

In yet another embodiment, the transmitter section includes an oscillator that produces an oscillation. The outbound symbol provides frequency information (e.g., +/−Δf [frequency shift] and/or f(t) [frequency modulation]) that adjusts the frequency of the oscillation to produce a frequency adjusted RF or MMW signal, which is transmitted as the outbound RF or MMW signal 60. In another embodiment, the outbound symbol stream includes amplitude information, which is used to adjust the amplitude of the frequency adjusted RF or MMW signal to produce the outbound RF or MMW signal 60. In a further embodiment, the transmitter section includes an oscillator that produces an oscillation. The outbound symbol provides amplitude information (e.g., +/−ΔA [amplitude shift] and/or A(t) [amplitude modulation) that adjusts the amplitude of the oscillation to produce the outbound RF or MMW signal 60.

The receiver section amplifies an inbound RF or MMW signal 60 to produce an amplified inbound RF or MMW signal. The receiver section may then mix in-phase (I) and quadrature (Q) components of the amplified inbound RF or MMW signal with in-phase and quadrature components of a local oscillation to produce a mixed I signal and a mixed Q signal. The mixed I and Q signals are combined to produce an inbound symbol stream. In this embodiment, the inbound symbol may include phase information (e.g., +/−Δθ [phase shift] and/or θ(t) [phase modulation]) and/or frequency information (e.g., +/−Δf [frequency shift] and/or f(t) [frequency modulation]). In another embodiment and/or in furtherance of the preceding embodiment, the inbound RF or MMW signal includes amplitude information (e.g., +/−ΔA [amplitude shift] and/or A(t) [amplitude modulation]). To recover the amplitude information, the receiver section includes an amplitude detector such as an envelope detector, a low pass filter, etc.

The processing module 50 generates the outbound symbol stream from outbound data and converts the inbound symbol stream into inbound data. For example, the processing module 50 converts the inbound symbol stream into inbound data (e.g., voice, text, audio, video, graphics, etc.) in accordance with one or more wireless communication standards (e.g., GSM, CDMA, WCDMA, HSUPA, HSDPA, WiMAX, EDGE, GPRS, IEEE 802.11, Bluetooth, ZigBee, universal mobile telecommunications system (UMTS), long term evolution (LTE), IEEE 802.16, evolution data optimized (EV-DO), etc.). Such a conversion may include one or more of: digital intermediate frequency to baseband conversion, time to frequency domain conversion, space-time-block decoding, space-frequency-block decoding, demodulation, frequency spread decoding, frequency hopping decoding, beamforming decoding, constellation demapping, deinterleaving, decoding, depuncturing, and/or descrambling.

As another example, the processing module 50 converts outbound data (e.g., voice, text, audio, video, graphics, etc.) into outbound symbol stream in accordance with one or more wireless communication standards (e.g., GSM, CDMA, WCDMA, HSUPA, HSDPA, WiMAX, EDGE, GPRS, IEEE 802.11, Bluetooth, ZigBee, universal mobile telecommunications system (UMTS), long term evolution (LTE), IEEE 802.16, evolution data optimized (EV-DO), etc.). Such a conversion includes one or more of: scrambling, puncturing, encoding, interleaving, constellation mapping, modulation, frequency spreading, frequency hopping, beamforming, space-time-block encoding, space-frequency-block encoding, frequency to time domain conversion, and/or digital baseband to intermediate frequency conversion.

Each of the one or more functional modules 54 provides a function to support treatment, data gathering, motion, repairs, and/or diagnostics. The functional modules 54 may be implemented using nanotechnology and/or microelectronic mechanical systems (MEMS) technology. Various examples of functional modules 54 are illustrated in one or more of FIGS. 16-20.

The bio-medical unit 10 may be encapsulated by an encapsulate 58 that is non-toxic to the body. For example, the encapsulate 58 may be a silicon based product, a non-ferromagnetic metal alloy (e.g., stainless steel), etc. As another example, the encapsulate 58 may include a spherical shape and have a ferromagnetic liner that generates magnetic fields to shield the unit from a magnetic field and to offset the forces of the magnetic field.

The bio-medical unit 10 may be implemented on a single die that has an area of a few millimeters or less. The die may be fabricated in accordance with CMOS technology, Gallium-Arsenide technology, and/or any other integrated circuit die fabrication process. The metal traces of the die may be of a non-magnetic metal alloy to minimize adverse affects by the magnetic fields.

FIG. 8A is a schematic block diagram of another embodiment of a bio-medical unit 10 that includes a power harvesting module 46, a communication module 48, a processing module 50, memory 52, and one or more functional modules 54. The power harvesting module 46 includes two or more power harvesting units 47 and a supply voltage circuit 45. Each of the power harvesting units 47 generates a supply voltage, which the supply voltage circuit 45 uses at least two of the supply voltages to generate the supply voltage 56.

The power harvesting units 47 may be of different constructs and/or the same construct. For example, the power harvesting module 46 may include one or more of a first power harvesting unit, one or more of a second power harvesting unit, one or more of a third power harvesting unit, and/or one or more of a fourth power harvesting unit. A first power harvesting unit includes an array of air core inductors, a rectifier circuit, and a regulation circuit. The array of air core inductors is operably coupled to produce an AC voltage from the magnetic field energy 16. The rectifier circuit is operably coupled to rectify the AC voltage to produce a voltage. The regulation circuit is operably coupled to regulate the voltage to produce a first supply voltage. A corresponding embodiment is further described with reference to FIG. 9.

A second power harvesting unit includes a plurality of air core inductors, a plurality of switching elements, a rectifier circuit, and a switch controller. The plurality of switching elements interconnects, based on a control signal, at least some of the plurality of inductors to produce a configured inductor that produces an AC voltage from the magnetic field energy 16. The rectifier circuit is operably coupled to rectify the AC voltage to produce a second supply voltage. The switch controller is operably coupled to generate the control signal such that the second supply voltage is at a desired voltage level. A corresponding embodiment is further described with reference to FIG. 10.

A third power harvesting unit includes a plurality of Hall effect devices and a power combining module. The plurality of Hall effect devices is operable to generate a plurality of voltages from the magnetic field energy 16. The power combining module is operably coupled to selectively combine the plurality of voltages to produce a third supply voltage. A corresponding embodiment is further described with reference to FIG. 11.

A fourth power harvesting unit includes a plurality of piezoelectric devices and a power combining module. The plurality of piezoelectric devices is operable to generate a plurality of voltages from the magnetic field energy 16. In this instance, the piezoelectric devices are doped with a magnetic material to induce motion. The power combining module is operably coupled to selectively combine the plurality of voltages to produce a fourth supply voltage. A corresponding embodiment is further described with reference to FIG. 12.

FIG. 8B is a schematic block diagram of another embodiment of a bio-medical unit 10 that includes a power harvesting module 46, a communication module 48, a second power harvesting module 49, a processing module 50, memory 52, and one or more functional modules 54. In an embodiment, the second power harvesting module includes a plurality of piezoelectric devices and a power combining module. The plurality of piezoelectric devices is operable to generate a plurality of voltages based on an ultrasound signal 51. The power combining module is operably coupled to selectively combine the plurality of voltages to produce a second supply voltage 56.

In another embodiment, the second power harvesting module includes an energy conversion unit 53 and a supply voltage generation circuit 55. The energy conversion unit 53 is operably coupled to receive an ultrasound signal 51 and to produce one or more voltages from the ultrasound signal 51. The supply voltage generation circuit 55 is operably coupled to convert the one or more voltages into a supply voltage 56. Note that the energy conversion unit 53 may include a plurality of piezoelectric devices and the supply voltage generation circuit 55 may include a power combining module.

FIG. 9 is a schematic block diagram of an embodiment of a power harvesting module 46 that includes an array of on-chip air core inductors 64, a rectifying circuit 66, capacitors, and a regulation circuit 68. The inductors 64 may each having an inductance of a few nano-Henries to a few micro-Henries and may be coupled in series, in parallel, or a series parallel combination.

In an example of operation, the MRI transmitter 20 transmits MRI signals 28 at a frequency of 3-45 MHz at a power level of up to 35 KWatts. The air core inductors 64 are electromagnetically coupled to generate a voltage from the magnetic and/or electric field generated by the MRI signals 28. Alternatively or in addition to, the air core inductors 64 may generate an AC voltage from the magnetic field 26 and changes thereof produced by the gradient coils. The rectifying circuit 66 rectifies the AC voltage produced by the inductors to produce a DC voltage. The regulation circuit 68 generates one or more desired supply voltages 56 from the DC voltage.

The inductors 64 may be implemented on one more metal layers of the die and include one or more turns per layer. Note that trace thickness, trace length, and other physical properties affect the resulting inductance. Further note that a non-magnetic metal alloy may be used for the traces.

FIG. 10 is a schematic block diagram of another embodiment of a power harvesting module 46 that includes a plurality of on-chip air core inductors 70, a plurality of switching units (S), a rectifying circuit 66, a capacitor, and a switch controller 72. The inductors 70 may each having an inductance of a few nano-Henries to a few micro-Henries and may be coupled in series, in parallel, or a series parallel combination.

In an example of operation, the MRI transmitter 20 transmits MRI signals 28 at a frequency of 3-45 MHz at a power level of up to 35 KWatts. The air core inductors 70 are electromagnetically coupled to generate a voltage from the magnetic and/or electric field generated by the MRI signals 28. The switching module 72 engages the switches via control signals 74 to couple the inductors 70 in series and/or parallel to generate a desired AC voltage. The rectifier circuit 66 and the capacitor(s) convert the desired AC voltage into the one or more supply voltages 56.

As another example of operation, the plurality of switching elements (S) interconnects, based on a control signal 74, at least some of the plurality of inductors 70 to produce a configured inductor. The configured inductor produces an AC voltage from the magnetic field energy, which includes MRI signals 28. The rectifier circuit is operably coupled to rectify the AC voltage to produce the supply voltage 56. The switch controller is operably coupled to generate the control signal 74 such that the supply voltage 56 is at a desired voltage level.

FIG. 11 is a schematic block diagram of another embodiment of a power harvesting module 46 that includes a plurality of Hall effect devices 76, a power combining module 78, and a capacitor(s). In an example of operation, the Hall effect devices 76 generate a voltage based on the constant magnetic field (H) and/or a varying magnetic field. The power combining module 78 (e.g., a wire, a switch network, a transistor network, a diode network, etc.) combines the voltages of the Hall effect devices 76 to produce the one or more supply voltages 56.

FIG. 12 is a schematic block diagram of another embodiment of a power harvesting module 46 that includes a plurality of piezoelectric devices 82, a power combining module 78, and a capacitor(s). In an example of operation, the piezoelectric devices 82 generate a voltage based on body movement, ultrasound signals, movement of body fluids, etc. The power combining module 78 (e.g., a wire, a switch network, a transistor network, a diode network, etc.) combines the voltages of the Hall effect devices 82 to produce the one or more supply voltages 56. Note that the piezoelectric devices 82 may include one or more of a piezoelectric motor, a piezoelectric actuator, a piezoelectric sensor, and/or a piezoelectric high voltage device.

In another embodiment, the piezoelectric devices 82 may be doped with a magnetic material such that, when in the presence of the magnetic field energy 16, movement of the piezoelectric devices 82 is induced. The piezoelectric devices 82 convert the movement into voltages that is combined to produce the supply voltage 56.

The various embodiments of the power harvesting module 46 may be combined to generate more power, more supply voltages, etc. For example, the embodiment of FIG. 9 may be combined with one or more of the embodiments of FIGS. 11 and 12.

FIG. 13 is a schematic block diagram of an embodiment of a bio medical system that includes a power boost module 84 and one or more implanted bio-medical units 10. The power boost module 84 rests on the body of the person under test or treatment and includes an electromagnetic (EM) power harvesting module 86 and a generator 88. The

EM power harvesting module 86 harvests energy from magnetic field energy (e.g., MRI signals 28) to produce a voltage. The generator 88 is powered by the voltage and generates an electromagnetic transmission 92 that it provides to the bio-medical units(s) 10. Note that the electromagnetic transmission 92 has a frequency (e.g., >45 MHz) that is greater than a frequency of the magnetic field energy (e.g., 3-45 MHz). Further note that the power boosting module 84 can recover significantly more energy than a bio-medical unit 10 since it can be significantly larger. For example, a bio-medical unit 10 may have an area of a few millimeters squared while the power boosting module 84 may have an area of a few to tens of centimeters squared.

In one embodiment, the electromagnetic power harvesting unit 86 receives varying gradient magnetic fields of magnetic resonance imaging (MRI) signals, wherein the magnetic field energy include the MRI signals. The electromagnetic power harvesting unit 86 induces an alternating current from the varying gradient magnetic fields and converts the alternating current into the voltage.

In another embodiment, the electromagnetic power harvesting unit 86 receives radio frequency (RF) transmission burst signals of magnetic resonance imaging (MRI) signals, wherein the magnetic field energy include the MRI signals. The electromagnetic power harvesting unit 86 converts the RF transmission burst signals into the voltage.

Other embodiments of the electromagnetic power harvesting unit 86 will be described in greater detail with reference to FIGS. 14 and 15.

An embodiment of the generator 88 generates a varying magnetic field, wherein the varying magnetic field corresponds to the electromagnetic transmission 92. In this instance, the generator 88 produces a second alternating magnetic field at a higher frequency than the magnetic field of an MRI device that is used by the bio-medical units 10 to recover power. Other embodiments of the generator 88 will be described with reference to FIGS. 13A, 13B, and 15A.

A bio-medical unit 10 includes a power harvesting module 90, which may be one or more of the power harvesting modules previously discussed, converts the electromagnetic transmission 92 into a supply voltage. The bio-medical unit 10 may also include a processing module, memory, and one or more functional modules all of which are powered by the supply voltage.

FIG. 13A is a schematic block diagram of an embodiment of the generator 88 that includes a continuous wave generator 89 and a transmitter module 91. The CW generator 89 is powered by the voltage produced by the EM power harvesting module 86 and generates a continuous wave signal that may be an RF signal (e.g., up to 3 GHz) and/or a MMW signal (e.g., up to 300 GHz). The CW generator 89 may be a phase locked loop (PLL), a digital frequency synthesizer (DFS), a voltage controlled oscillator (VCO), and/or a resonant tank circuit. The transmitter module 91, which may be an RF transmitter and/or a MMW transmitter, wirelessly transmits the continuous wave signal 93 to the bio-medical units 10.

FIG. 13B is a schematic block diagram of an embodiment of the generator 88 that includes the continuous wave generator 89, a transceiver module 95, and a processing module 97. In this embodiment, power booster module 84 provides wireless power to the bio-medical unit 10 and communicates with the bio-medical unit 10. The transceiver module 95 and the processing module 97 may be of a similar construct of the communication module and the processing module described with reference to FIG. 8.

For a communication with the bio-medical unit 10, the processing module 97 generates an outbound message (e.g., read command, write command, data gather, etc.). The transceiver module 95 wirelessly transmits the outbound message as an outbound wireless signal to the bio-medical unit.

The communication module of the bio-medical unit 10 the outbound wireless signal and converts it into a receive symbol stream. The processing module of the bio-medical unit 10 convert the receive symbol stream into the outbound message.

For communications from the unit 10 to the module 84, the processing module of the unit 10 converts an inbound message into a transmit symbol stream. The wireless transceiver of the unit 10 converts the transmit symbol stream into the inbound wireless signal and transmits it to the on body power booster module 84.

The transceiver module 95 receives the inbound wireless signal and converts it into an inbound symbol stream. The processing module 97 converts the inbound symbol stream into the inbound message. In this manner, the booster module 84 further acts to boost the communication range of implanted bio-medical units 10.

FIG. 14 is a schematic block diagram of an embodiment of an electromagnetic (EM)) power harvesting module 86 that includes inductors, diodes (or transistors) and a capacitor. The inductors may each be a few mili-Henries such that the power boost module can deliver up to 10′s of mili-watts of power. In operation, the inductors generate an AC voltage from the magnetic field energy. The diodes and/or transistors convert the AC voltage into a rectified voltage that is filtered by the capacitor to produce the supply voltage. Note that the diodes and/or transistors and the capacitor provide a rectifying module.

FIG. 15 is a schematic block diagram of another embodiment of an electromagnetic (EM)) power harvesting module 86 that includes a plurality of Hall effect devices 76, a power combining module 78, and a capacitor. This functions as described with reference to FIG. 11, but the Hall effect devices 76 can be larger such that more power can be produced. Note that the EM power harvesting module 86 may include a combination of the embodiment of FIG. 14 and the embodiment of FIG. 15.

FIG. 15A is a schematic block diagram of an embodiment of the generator 88 that includes an oscillating circuit 81, a switching circuit 83, an inductor, and a diode or transistor. The oscillating circuit 81 (e.g. a PLL, a VCO, a tank circuit, a DFS, etc.) generates an oscillation. The switching circuit 83 connects and disconnects the inductor to the voltage 56 at a rate established by the oscillation such that the inductor generates a varying magnetic field that is wirelessly transmitted to the bio-medical unit 10 as a wireless power source. In an embodiment, the inductor including a magnetic material core (e.g., ferrite) and the switching circuit 83 disconnects the inductor from the voltage when receiving varying gradient magnetic fields of magnetic resonance imaging (MRI) signals.

FIG. 16 is a schematic block diagram of another embodiment of a bio-medical unit 10 that includes a power harvesting module 46, a communication module 48, a processing module 50, memory 52, and may include one or more functional modules 54 and/or a Hall effect communication module 116. The communication module 48 may include one or more of an ultrasound transceiver 118, an electromagnetic transceiver 122, an RF and/or MMW transceiver 120, and a light source (LED) transceiver 124. Note that if the communication module 48 includes the RF and/or MMW transceiver 120r it may be coupled to a leaky antenna 94, which will be described in greater detail with reference to FIGS. 42-45. Further note that examples of the various types of communication modules 48 will be described in greater detail with reference to one or more of FIGS. 17-76.

The one or more functional modules 54 may include a motion propulsion module 96, a camera module 98, a sampling robotics module 100, a treatment robotics module 102, an accelerometer module 104, a flow meter module 106, a transducer module 108, a gyroscope module 110, a high voltage generator module 112, and a control release robotics module 114. The functional modules 54 may be implemented using MEMS technology and/or nanotechnology. For example, the camera module 98 may be implemented as a digital image sensor in MEMS technology. Example of these various modules will be described in greater detail with reference to one or more of FIGS. 17-76.

The Hall effect communication module 116 utilizes variations in the magnetic field and/or electrical field to produce a plus or minus voltage, which can be encoded to convey information. For example, the charge applied to one or more Hall effect devices 76 may be varied to produce the voltage change. As another example, an MRI transmitter 20 and/or gradient unit may modulate a signal on the magnetic field 26 it generates to produce variations in the magnetic field 26.

FIG. 17 is a diagram of another embodiment of the bio medical system that includes one or more bio-medical units 10, a transmitter of the on body power boost module 84, and a receiver of the on body power boost module 84. Each of the bio-medical units 10 includes a power harvesting module 46, a MMW transceiver 138, a processing module 50, and memory 52. The transmitter of the on body power boost module 84 may include a RF transmitter and/or a MMW transmitter. The receiver of the on body power boost module 84 may include a RF receiver and/or a MMW receiver.

In an example of operation, the bio-medical unit 10 recovers power from electromagnetic (EM) transmissions 92 and communicates via MMW signals 148-150 with the on body power boosting module 84. The communication may be done using backscattering or another signaling protocol (e.g., signal modulation protocol (e.g., BPSK, QPSK, MSK, GMSK, etc.) and a signal transmission protocol (e.g., TDMA, FDMA, CDMA, etc.).

FIG. 18 is a diagram of an example of a communication protocol within the system of FIG. 17. In this diagram, the MRI transmitter 20 transmits RF signals 152, which have a frequency in the range of 3-45 MHz, at various intervals with varying signal strengths. The power harvesting module 86 of the on body power boosting module 84 may use these signals to generate power for the bio-medical unit 10.

In addition to the MRI transmitter 20 transmitting its signal, various gradient magnetic fields 154-164 are created (one or more in the x dimension Gx, one or more in the y dimension Gy, and one or more in the z direction Gz). The power harvesting module 86 of the power boosting module 84 may further use the varying magnetic fields 154-164 to create power for the bio-medical unit 10.

During non-transmission periods of the cycle, the bio-medical unit 10 may communicate 168 with the power boosting module 84. In this regard, the power boosting module 84 alternates from generating power to MMW communication in accordance with the conventional transmission-magnetic field pattern of an MRI machine. Note that if the system does not include a power boosting module 84, the units 10 function similarly to recover power and communication as described.

FIG. 19 is a diagram of another embodiment of a system includes one or more bio-medical units 10, a transmitter of the on body power boosting module 84, and a receiver of the on body power boosting module 84. Each of the bio-medical units 10 includes a power harvesting module 46, an EM transceiver 174, a processing module 50, and memory 52. The transmitter of the on body power boosting module 84 may include an electromagnetic (EM) modulator. The receiver of the on body power boosting module 84 includes an EM demodulator.

In an example of operation, an MRI transmitter generates an electromagnetic signal that is received by the EM modulator of the on body power boosting module 84. The EM modulator modulates a communication signal on the EM signal to produce an inbound modulated EM signal 176. The EM modulator may modulate (e.g., amplitude modulation, frequency modulation, amplitude shift keying, frequency shift keying, etc.) the magnetic field and/or electric field of the EM signal. In another embodiment, the EM modulator may modulate the magnetic fields produced by the gradient coils to produce the inbound modulated EM signals 176.

The bio-medical unit 10 recovers power from the modulated electromagnetic (EM) signals. In addition, the EM transceiver 174 demodulates the modulated EM signals 178 to recover the communication signal. For outbound signals, the EM transceiver 174 modulates an outbound communication signal to produce outbound modulated EM signals 180. In this instance, the EM transceiver 174 is generating an EM signal that, in air, is modulated on the EM signal transmitted by the transmitter of the on body power boosting module 84. In one embodiment, the communication in this system is half duplex such that the modulation of the inbound and outbound communication signals is at the same frequency. In another embodiment, the modulation of the inbound and outbound communication signals are at different frequencies to enable full duplex communication.

FIG. 20 is a diagram of another example of a communication protocol within the system of FIG. 19. In this diagram, the MRI transmitter transmits RF signals 152, which have a frequency in the range of 3-45 MHz, at various intervals with varying signal strengths. The power harvesting module 86 of the on body power boosting module 84 may use these signals to generate power for the bio-medical unit 10.

In addition to the MRI transmitter transmitting its signal, various gradient magnetic fields are created 154-164 (one or more in the x dimension Gx, one or more in the y dimension Gy, and one or more in the z direction Gz). The power harvesting module 86 of the on body power boosting module 84 may further use the varying magnetic fields 154-164 to create power for the bio-medical unit 10.

During the transmission periods of the cycle, the on body power boosting module 84 may communicate with the bio medical units 10 via the modulated EM signals 182. In this regard, the on body power boosting module 84 generates power and communicates in accordance with the conventional transmission-magnetic field pattern of an MRI machine. Note that if the system does not include a power boosting module 84, the units 10 function similarly to recover power and communication as described.

As may be used herein, the terms “substantially” and “approximately” provides an industry-accepted tolerance for its corresponding term and/or relativity between items. Such an industry-accepted tolerance ranges from less than one percent to fifty percent and corresponds to, but is not limited to, component values, integrated circuit process variations, temperature variations, rise and fall times, and/or thermal noise. Such relativity between items ranges from a difference of a few percent to magnitude differences. As may also be used herein, the term(s) “coupled to” and/or “coupling” and/or includes direct coupling between items and/or indirect coupling between items via an intervening item (e.g., an item includes, but is not limited to, a component, an element, a circuit, and/or a module) where, for indirect coupling, the intervening item does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As may further be used herein, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two items in the same manner as “coupled to”. As may even further be used herein, the term “operable to” indicates that an item includes one or more of power connections, input(s), output(s), etc., to perform one or more its corresponding functions and may further include inferred coupling to one or more other items. As may still further be used herein, the term “associated with”, includes direct and/or indirect coupling of separate items and/or one item being embedded within another item. As may be used herein, the term “compares favorably”, indicates that a comparison between two or more items, signals, etc., provides a desired relationship. For example, when the desired relationship is that signal 1 has a greater magnitude than signal 2, a favorable comparison may be achieved when the magnitude of signal 1 is greater than that of signal 2 or when the magnitude of signal 2 is less than that of signal 1.

The present invention has also been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claimed invention.

The present invention has been described above with the aid of functional building blocks illustrating the performance of certain significant functions. The boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality. To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claimed invention. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof.

Claims

1. A bio-medical unit comprises:

a power harvesting module operable to: receive magnetic field energy; and convert the magnetic field energy into a supply voltage;

a processing module powered by the supply voltage;

memory operably coupled to the processing module and powered by the supply voltage; and

one or more functional modules operably coupled to the processing module and powered by the supply voltage.

2. The bio-medical unit of claim 1, wherein the power harvesting module is further operable to:

receive varying gradient magnetic fields of magnetic resonance imaging (MRI) signals, wherein the magnetic field energy include the MRI signals;

induce an alternating current from the varying gradient magnetic fields;

convert the alternating current into a voltage; and

regulate the voltage to produce the supply voltage.

3. The bio-medical unit of claim 1, wherein the power harvesting module is further operable to:

receive radio frequency (RF) transmission burst signals of magnetic resonance imaging (MRI) signals, wherein the magnetic field energy include the MRI signals;

convert the RF transmission burst signals into a voltage; and

regulate the voltage to produce the supply voltage.

4. The bio-medical unit of claim 1, wherein the power harvesting module comprises:

an array of air core inductors operably coupled to produce an AC voltage from the magnetic field energy;

a rectifier circuit operably coupled to rectify the AC voltage to produce a voltage; and

a regulation circuit operably coupled to regulate the voltage to produce the supply voltage.

5. The bio-medical unit of claim 1, wherein the power harvesting module comprises:

a plurality of air core inductors;

a plurality of switching elements coupled to the plurality of inductors, wherein, based on a control signal, the plurality of switching interconnect at least some of the plurality of inductors to produce a configured inductor and wherein the configured inductor produces an AC voltage from the magnetic field energy;

a rectifier circuit operably coupled to rectify the AC voltage to produce the supply voltage; and

a switch controller operably coupled to generate the control signal such that the supply voltage is at a desired voltage level.

6. The bio-medical unit of claim 1, wherein the power harvesting module comprises:

a plurality of Hall effect devices operable to generate a plurality of voltages from the magnetic field energy; and

a power combining module operably coupled to selectively combine the plurality of voltages to produce the supply voltage.

7. The bio-medical unit of claim 1, wherein the power harvesting module comprises:

a plurality of piezoelectric devices operable to generate a plurality of voltages from the magnetic field energy, wherein a piezoelectric device of the plurality of piezoelectric devices is doped with a magnetic material to induce motion; and

a power combining module operably coupled to selectively combine the plurality of voltages to produce the supply voltage.

8. The bio-medical unit of claim 1, wherein the power harvesting module comprises at least two of:

a first power harvesting unit that includes: an array of air core inductors operably coupled to produce an AC voltage from the magnetic field energy; a rectifier circuit operably coupled to rectify the AC voltage to produce a voltage; and a regulation circuit operably coupled to regulate the voltage to produce a first supply voltage;

a second power harvesting unit that includes: a plurality of air core inductors; a plurality of switching elements coupled to the plurality of inductors, wherein, based on a control signal, the plurality of switching interconnect at least some of the plurality of inductors to produce a configured inductor and wherein the configured inductor produces an AC voltage from the magnetic field energy; a rectifier circuit operably coupled to rectify the AC voltage to produce a second supply voltage; and a switch controller operably coupled to generate the control signal such that the second supply voltage is at a desired voltage level;

a third power harvesting unit that includes: a plurality of Hall effect devices operable to generate a first plurality of voltages from the magnetic field energy; and a power combining module operably coupled to selectively combine the first plurality of voltages to produce a third supply voltage;

a fourth power harvesting unit that includes: a plurality of piezoelectric devices operable to generate a second plurality of voltages from the magnetic field energy, wherein a piezoelectric device of the plurality of piezoelectric devices is doped with a magnetic material to induce motion; and a power combining module operably coupled to selectively combine the second plurality of voltages to produce a fourth supply voltage; and

a supply voltage circuit operably coupled to generate the supply voltage from at least two of the first, second, third, and fourth supply voltages.

9. The bio-medical unit of claim 1 further comprises:

an integrated circuit (IC) die that support the power harvesting module, the processing module, the memory, and the one or more functional modules, wherein traces of the IC die are non-magnetic and electrically conductive.

10. The bio-medical unit of claim 1 further comprises:

a second power harvesting module that includes: a plurality of piezoelectric devices operable to generate a plurality of voltages based on an ultrasound signal; and a power combining module operably coupled to selectively combine the plurality of voltages to produce a second supply voltage.

11. A power harvesting module comprises:

an energy conversion unit operably coupled to: receive magnetic resonance imaging (MRI) signals; and produce one or more voltages from the MRI signals; and

a supply voltage generation circuit operably coupled to convert the one or more voltages into a supply voltage.

12. The power harvesting module of claim 11, wherein the energy conversion unit is further operable to:

receive varying gradient magnetic fields of the MRI signals;

induce an alternating current from the varying gradient magnetic fields; and

convert the alternating current into the one or more voltage.

13. The power harvesting module of claim 11, wherein the energy conversion unit is further operable to:

receive radio frequency (RF) transmission burst signals of the MRI signals; and

convert the RF transmission burst signals into the one or more voltage.

14. The power harvesting module of claim 11 further comprises:

the energy conversion unit including: an array of air core inductors operably coupled to produce an AC voltage from the MRI signals; and a rectifier circuit operably coupled to rectify the AC voltage to produce the one or more voltages;

the supply voltage generation circuit including a regulation circuit operably coupled to regulate the one or more voltages to produce the supply voltage.

15. The power harvesting module of claim 11 further comprises:

the energy conversion unit including: a plurality of air core inductors; and a plurality of switching elements coupled to the plurality of inductors, wherein, based on a control signal, the plurality of switching interconnect at least some of the plurality of inductors to produce a configured inductor and wherein the configured inductor produces an AC voltage from the MRI signals, wherein the AC voltage corresponds to the one or more voltages;

the supply voltage generation circuit including: a rectifier circuit operably coupled to rectify the AC voltage to produce the supply voltage; and a switch controller operably coupled to generate the control signal such that the supply voltage is at a desired voltage level.

16. The power harvesting module of claim 11 further comprises:

the energy conversion unit including a plurality of Hall effect devices operable to generate a plurality of voltages the one or more voltages from the MRI signals, wherein the plurality of voltages corresponds to the one or more voltages; and

the supply voltage generation circuit including a power combining module operably coupled to selectively combine the plurality of voltages to produce the supply voltage.

17. The power harvesting module of claim 11 further comprises:

the energy conversion unit including a plurality of piezoelectric devices operable to generate a plurality of voltages from the MRI signals, wherein a piezoelectric device of the plurality of piezoelectric devices is doped with a magnetic material to induce motion and wherein the plurality of voltages corresponds to the one or more voltages; and

the supply voltage generation circuit including a power combining module operably coupled to selectively combine the plurality of voltages to produce the supply voltage.

18. The power harvesting module of claim 11 further comprises at least two of:

a first power harvesting unit that includes: a first energy conversion unit including: an array of air core inductors operably coupled to produce an AC voltage from the MRI signals, wherein the one or more voltages includes the AC voltage corresponds; a rectifier circuit operably coupled to rectify the AC voltage to produce a voltage; and a first supply voltage generation circuit including a regulation circuit operably coupled to regulate the voltage to produce a first supply voltage;

a second power harvesting unit that includes: a second energy conversion unit including: a plurality of air core inductors; and a plurality of switching elements coupled to the plurality of inductors, wherein, based on a control signal, the plurality of switching interconnect at least some of the plurality of inductors to produce a configured inductor and wherein the configured inductor produces an AC voltage from the MRI signals, wherein the one or more voltages include the AC voltage;

a second supply voltage generation circuit including: a rectifier circuit operably coupled to rectify the AC voltage to produce a second supply voltage; and a switch controller operably coupled to generate the control signal such that the second supply voltage is at a desired voltage level;

a third power harvesting unit that includes: a third energy conversion unit including a plurality of Hall effect devices operable to generate a first plurality of voltages from the MRI signals, wherein the one or more voltages includes the first plurality of voltages; and a third supply voltage generation circuit including a power combining module operably coupled to selectively combine the first plurality of voltages to produce a third supply voltage;

a fourth power harvesting unit that includes: a fourth energy conversion unit including: a plurality of piezoelectric devices operable to generate a second plurality of voltages from the MRI signals, wherein a piezoelectric device of the plurality of piezoelectric devices is doped with a magnetic material to induce motion and wherein the one or more voltages includes the second plurality of voltages; and a fourth supply voltage generation circuit including a power combining module operably coupled to selectively combine the second plurality of voltages to produce a fourth supply voltage; and

a supply voltage circuit operably coupled to generate the supply voltage from at least two of the first, second, third, and fourth supply voltages.

19. A power harvesting module comprises:

an energy conversion unit operably coupled to: receive an ultrasound signal; and produce one or more voltages from the ultrasound signal; and

a supply voltage generation circuit operably coupled to convert the one or more voltages into a supply voltage.

20. The power harvesting module of claim 19 further comprises:

the energy conversion unit including a plurality of piezoelectric devices operable to generate a plurality of voltages from the ultrasound signal, wherein the plurality of voltages corresponds to the one or more voltages; and

the supply voltage generation circuit including a power combining module operably coupled to selectively combine the plurality of voltages to produce the supply voltage.