Device for transmitting energy and data and method for operating such device

Abstract

Energy transmission device for the wireless transmission of energy to an active implant, comprising: a transmitter coil adapted for electrical connection to an energy source, and an implantable receiver coil adapted for inductive coupling to the transmitter coil for wireless energy transmission, wherein an implantable primary coil is electrically connected to a modulator, the modulator modulating an AC voltage supplied to the implantable primary coil based on a data signal so that data transmission from the implantable primary coil to an extracorporeal secondary coil is performed, the frequency of the data transmission being different from the frequency at which the energy is transmitted from the transmitter coil to the receiver coil, and wherein information regarding the energy control of the energy to be transmitted from the transmitter coil is transmitted from the primary coil to the secondary coil by a pulse width modulated signal, other information not regarding the energy control is transmitted by means of a frequency modulation of the carrier frequency of the pulse width modulated signal or by a modulation of the frequency at which the pulses of the pulse width modulated signal are transmitted.

Claims

1. An energy transmission device for the wireless transmission of energy to an active implant, comprising a transmitter coil adapted for electrical connection to an energy source, and an implantable receiver coil adapted for inductive coupling to the transmitter coil for wireless energy transmission, wherein an implantable primary coil is electrically connected to a modulator, the modulator modulating an AC voltage supplied to the implantable primary coil based on a data signal so that data transmission from the implantable primary coil to an extracorporeal secondary coil is performed, the frequency of the data transmission being different from the frequency at which the energy is transmitted from the transmitter coil to the receiver coil, wherein information regarding the energy control of the energy to be transmitted from the transmitter coil is transmitted from the primary coil to the secondary coil by a pulse width modulated signal, other information not regarding the energy control is transmitted by a frequency modulation of the carrier frequency of the pulse width modulated signal or by a modulation of the frequency at which the pulses of the pulse width modulated signal are transmitted.

2. The energy transmission device of claim 1, wherein the carrier frequencies of the pulse width modulated signal range from 1 Megahertz to 13 Megahertz.

3. The energy transmission device claim 1, wherein the pulses of the pulse width modulated signal are transmitted at a frequency of between about 1 kilohertz to 20 kilohertz.

4. The energy transmission device of claim 1, wherein the other information is transmitted in a non-clocked manner, i.e. via an asynchronous communication channel.

5. The energy transmission device of claim 1, wherein the implanted primary coil is the receiver coil and/or the extracorporeal secondary coil is the transmitter coil.

6. The energy transmission device of claim 1, wherein the modulator is inductively coupled to an electric conductor via a transformer, the conductor being connected to the implanted primary coil.

7. The energy transmission device of claim 1, wherein the frequency of the data transmission from the implanted primary coil to the extracorporeal secondary coil is higher than the frequency at which the energy is transmitted from the transmitter coil to the receiver coil.

8. The energy transmission device of claim 1, further comprising a second transformer for an inductive decoupling of the data signal, which is received by the extracorporeal secondary coil, from an electric line connected to the extracorporeal secondary coil.

9. The energy transmission device of claim 1, further comprising a band pass filter allowing only the data transmission frequency to pass.

10. The energy transmission device of claim 1, further comprising a second modulator electrically connected to the extracorporeal secondary coil, for the modulation of an AC voltage supplied to the extracorporeal secondary coil on the basis of a second data signal to be transmitted from the extracorporeal secondary coil to the implanted primary coil.

11. The energy transmission device of claim 10, wherein the frequency used for the data transmission from the extracorporeal secondary coil to the implanted primary coil differs from the frequency used for the data transmission from the implanted primary coil to the extracorporeal secondary coil.

12. The energy transmission device of claim 10, wherein the modulation method used for the data transmission from the extracorporeal secondary coil to the implanted primary coil differs from the modulation method used for the data transmission from the implanted primary coil to the extracorporeal secondary coil.

13. A method for operating an energy transmission device for the wireless transmission of energy to an active implant, the method comprising the following steps: a) supplying an AC voltage to a transmitter coil, b) inductively coupling an implantable receiver coil to the transmitter coil so that an AC voltage is induced in the receiver coil, c) modulating an AC voltage supplied to the implanted primary coil in accordance to a data signal to be supplied from the implanted primary coil to the extracorporeal secondary coil, d) inducing a modulated AC voltage in the extracorporeal secondary coil by the modulated AC voltage of the implanted primary coil, e) extracting and evaluating the data signal received by the extracorporeal secondary coil, f) transmitting information regarding the energy control of the energy to be transmitted by the transmitter coil by a pulse width modulated signal from the implanted primary coil to the extracorporeal secondary coil, g) transmitting other information that do not regard the energy control by a frequency modulation of the carrier frequency of the pulse width modulated signal or by a modulation of the frequency at which the pulses of the pulse width modulated signals are transmitted.

14. The method of claim 13, further comprising the following method step: measuring the signal strength of the data signal received by the extracorporeal secondary coil, so that the quality of the inductive coupling between the transmission coil and the receiver coil is determined based thereon.

15. The method of claim 13, wherein in case of a modulation of the frequency at which the pulses of the pulse width modulated signals are transmitted, the pulse width is adjusted proportionally to the frequency at which the pulses of the pulse width modulated signal are transmitted.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In the Figures:

[0053] FIG. 1 illustrates the basic functioning of a wireless energy transmission,

[0054] FIG. 2 shows an electric circuit diagram of an embodiment of the device according to the disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0055] FIG. 1 has already been explained in the context of prior art.

[0056] The extracorporeal coil 14 is illustrated on the left in FIG. 2. The coil is connected to a power driver 30 for coupling the energy in that is to be transmitted from the transmitter coil 14 to the implantable receiver coil 16.

[0057] On the side of the implant, the receiver coil 16 is illustrated on the right in FIG. 2. The same is connected to the first transformer 20 which comprises a primary coil and a secondary coil. Its primary coil is connected to the modulator 18. The same is used to modulate an AC voltage according to a data signal to be transmitted from the receiver coil 16 to the transmitter coil 14. The primary coil of this transformer may e.g. have an inductivity of about 1 ?H.

[0058] A capacitor 32 is connected in parallel with the primary coil of the transformer 20 as a resonance capacitance, the capacitor forming a parallel resonant circuit together with the primary coil of the transformer 20, the circuit relieving the modulator.

[0059] 34 and 36 denote tuning capacitors for energy transmission.

[0060] The receiver coil 16 transmits the data signal at a frequency clearly above the frequency for the transmission of energy. Thereby, it can be ensured that the harmonics of the energy transmission do not interfere with the data signal. For example, an energy transmission frequency of 100 kHz and a data signal frequency of 455 kHz can be used.

[0061] Information regarding the energy control of the energy to be transmitted by the transmitter coil 14 is transmitted from the receiver coil 16 to the transmitter coil 14 by a pulse width modulated signal. Further, other information that does not regard the energy control is transmitted using a frequency modulation of the carrier frequency of the pulse width modulated signal or a modulation of the frequency at which the pulses of the pulse width modulated signal are transmitted. In the former variant the carrier frequency can be modulated between 12 Megahertz and 13 Megahertz, wherein e.g. 12 Megahertz correspond to a logical 1 and 13 Megahertz correspond to a logical 0. This is illustrated in FIG. 3.

[0062] In the latter variant the frequency at which the pulses are transmitted is changed. Here, it is necessary that the two frequencies used for a logical 1 and a logical 0 are a multiple of each other. For example, the frequencies 10 kilohertz and 20 kilohertz may be used. This means that two pulses at 20 kilohertz correspond to a logical 1 and one pulse at 10 kilohertz corresponds to a logical 0. In order to still enable energy control via pulse width modulation in parallel with the above, the pulse width is adapted proportionally to the frequency (10 kilohertz or 20 kilohertz in the embodiment illustrated) so that the duty cycle of the pulse width modulated signal still remains the same. Thus, when a logical 0 is transmitted, only an electrical pulse with a frequency of 10 kilohertz is transmitted. The same has twice the pulse width of the two pulses for a logical 1 transmitted at a frequency of 20 kilohertz (assuming that the same duty cycle is to be transmitted in both cases). This embodiment is illustrated in FIG. 4.

[0063] The data signal transmitted by the receiver coil 16 is received by the transmitter coil 14 and is routed to the second transformer 22. The latter has a primary coil connected to the electric line 24 which, in turn, is connected to the transmitter coil 14. This primary coil may have a rather low inductivity of e.g. 1 ?H and serves to decouple the high-frequency data signal. The same is then supplied to a prefilter 26 which preferably is a LC band pass filter. Thereby, the power frequency is limited prior to being supplied into the band pass filter.

[0064] The signal is then supplied to the band pass filter 28 which is a narrowband filter tuned to the data signal. The filter is preferably designed as a ceramic filter.

[0065] An amplifier 38 and a demodulator 40 are arranged downstream thereof.

[0066] The receiver coil 16 thus generates a magnetic field that corresponds to the data signal to be transmitted. The transmitter coil 14 picks up this magnetic field and generates a corresponding current which is coupled onto the evaluation circuit via the second transformer 22, the evaluation circuit comprising the prefilter 26, the band pass filter 28, the amplifier 38 and the modulator 40.

[0067] The output signal of the transformer 22 may at the same time be used to measure the primary current of the energy transmission.

[0068] Using a signal frequency of 455 kHz is particularly advantageous, because ceramic filters with very narrow bands are available for this frequency. Besides, it is of a sufficiently high frequency to provide a high data throughput.

[0069] The amplitude of the data signal may at the same time be used as a measure of the quality of the inductive coupling between the transmitter coil 14 and the receiver coil 16.

[0070] Basically, data transmission can also be performed from the transmitter coil 14 to the receiver coil 16. In this regard it is necessary to provide a corresponding modulator on the side of the transmitter coil 14, as well as the other components described, while on the implant side a corresponding evaluation circuit has to be provided. The corresponding circuit parts thus have to be switched.

[0071] Further, a bidirectional transmission is possible, wherein different frequencies are preferably used in this case.

[0072] It is further possible to use a plurality of frequencies in one direction and to thereby realize different data channels.