Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B11/00—Transmission systems employing sonic, ultrasonic or infrasonic waves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
  • A61B5/0026—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network characterised by the transmission medium
  • A61B5/0028—Body tissue as transmission medium, i.e. transmission systems where the medium is the human body
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
  • A61B5/0031—Implanted circuitry

Definitions

• the present invention relates to a method of wireless transmission between at least a first transducer located in a first location and at least a second transducer located in a second location remote from said first location, said at least two transducers being of the electroacoustic type.
• It also relates to a wireless transmission device between at least a first element comprising at least a first transducer, located in a first location, and at least a second element comprising at least a second transducer, located in a second location remote from said first location.
• said at least two transducers being of the electroacoustic type, for the implementation of this method.
• RFID radio frequency identification
• TAG the element that communicates with it and provides it with its energy
• the main applications of this type of wireless communication are very varied and include the identification of animals, the TAG being implanted under the skin of the animal, access monitoring, where the TAG replaces or complements a mechanical key , and the realization of antitheft systems.
• An RFID radio frequency identification can first be done by magnetic coupling.
• This embodiment is characterized by the fact that the energy and the information are transmitted from the interrogator to the TAG by a magnetic coupling of the transformer type. These systems use very low transmit frequencies, usually below 13 MHz, to ensure the purely magnetic nature of the transmitted waves.
• the TAG transmits the information by short-circuiting the coil serving as "antenna" to the rhythm of the information to be transmitted, this modification of the impedance of said coil de facto modulating the impedance of the load "seen” by the interrogator.
• the advantage of this embodiment is its low cost but, on the other hand, it has many drawbacks which are, among others, its low transmission range, the presence of an antenna of the interrogator commonly very large, and the very difficult, if not impossible, establishment of a communication when the TAG is close to a conductive structure (metal, ionic liquid, etc.).
• RFID systems that use elements of the "SAW” type (Surface Acoustic Wave) in which energy and information are transmitted from the TAG to the interrogator by the modulation of reflected electromagnetic waves.
• SAW Surface Acoustic Wave
• the transmission frequencies must be significantly higher than for magnetic coupling. The frequencies usually used are greater than a few hundred megahertz.
• One of the technologies used for the realization of such systems is the coupling of the TAG antenna to a SAW type component using acoustic surface waves to modify the properties of a reflected electromagnetic wave. The latter can then, by its structure and the different electrical or physical constraints that are applied to it, modify the nature of the reflected wave.
• the international publication WO 2007/073473 relates to a transmission device using elements of the SAW type, in which the communication clearly uses radiofrequency-based information transmission.
• this device comprises an antenna for the transfer of information and an electroacoustic element used as a sensor and directly modifying the radiofrequency characteristics of two SAW elements, thus modulating the radiofrequency characteristics of the device.
• this device is intended for radio transmissions in a high frequency range.
• This device uses an element allowing it to capture the energy found in the environment of its system, there is no external supply of energy.
• the piezo-acoustic element is only used as a sensor. Local energy recovery is performed by an energy capture element. No component is dedicated to the recovery of energy transmitted by a third party.
• the present invention proposes to provide a method and a wireless transmission device that overcomes all the disadvantages of the systems.
• identification system without prior wires, in which the communication for carrying information is based solely on acoustic waves, without any magnetic, electrical or electromagnetic wave content.
• the advantages of this method are numerous because it has a large transmission range due to excellent propagation in all environments, especially in the case where the other systems can not or poorly communicate, namely the propagation in the human body, through metal, in any solid medium, liquid or gel and even in the air.
• this transmission method can not be disturbed by external sources of electromagnetic waves, as is often the case for traditional RFIDs and does not itself generate any electromagnetic disturbance, especially in the case where it is used. in the context of the transport of information in the human body because the waves generated remain contained within the body.
• the size of the transducers of the TAG and the interrogator is relatively small, which significantly opens the scope of the device.
• the aims of the invention are achieved by a method as defined in the preamble and characterized in that acoustic waves are generated in said at least first transducer, in that said acoustic waves are emitted in the direction of said at least one second transducer, in that said acoustic waves are picked up in said at least second transducer, in that at least some of the acoustic waves received in said at least second transducer are at least partly converted into electrical energy, and in that storing said electrical energy in said at least second transducer.
• At least a portion of the electrical energy stored in said second transducer is used to process information.
• the mechanical states of said at least first transducer are modulated to emit said acoustic waves.
• At least a portion of the electrical energy stored in the second transducer is used to transmit information contained in said second transducer to said first transducer.
• the waves reflected by said second transducer are modulated to transmit information to said first transducer.
• the information contained in the reflected waves is centered around a subcarrier frequency of the frequency of said reflected waves.
• a phase, frequency, amplitude modulation or any combination of these three modulations is advantageously carried out.
• At least a portion of the electrical energy stored in said second transducer can be used to activate at least one actuator, to detect information derived and / or processed by at least one sensor and for transmitting to said first transducer the information acquired by said at least one sensor.
• the wireless transmission device as defined in the preamble is characterized in that it comprises means arranged for generating acoustic waves in said first transducer and for emitting these acoustic waves towards said second transducer, arranged means for sensing said acoustic waves in said second transducer, means arranged to at least partially convert said acoustic waves into electrical energy in said second transducer, and means arranged to store said electrical energy in said second transducer.
• said device may advantageously comprise means arranged for processing information. It may also include means arranged to transmit acoustic waves generated in the first transducer to a plurality of second transducers.
• the device comprises means arranged to modulate the waves reflected by said second transducer to transmit to said first transducer information contained in said second transducer.
• it also comprises means arranged to use the electrical energy stored in said second transducer to transmit this information.
• the device may comprise means arranged to use the electrical energy stored in said second transducer to activate at least one actuator, to read information derived and / or processed by at least one sensor and to transmit said information to first transducer.
• said second transducer is disposed in a transponder called TAG implanted in the human body.
• FIG. 1 is a general schematic diagram of the method according to the invention
• FIGS. 2A, 2B, 2C, 2D and 2E are schematic diagrams illustrating different configuration possibilities offered by the method according to the invention
• FIGS. 3A, 3B and 3C show the evolution of the power of the electroacoustic signal in an optimized variant of the method according to the invention at low flow rates and low consumption
• FIGS. 3A, 3B and 3C show the evolution of the power of the electroacoustic signal in an optimized variant of the method according to the invention at low flow rates and low consumption
• FIGS. 4A and 4B are diagrams of the elements of an embodiment of the device according to the invention intended to be implanted in the human body.
• the method of the invention consists in communicating acoustic and / or ultrasonic waves between at least two transducers T1 and T2, of the electroacoustic type, arranged at two different locations so that storing energy, processing information and capturing and / or actuating parameters recorded by a sensor and / or an actuator.
• the first transducer T1 is used to generate acoustic, sonic or ultrasonic waves, by modulating its mechanical states and emitting them to the second transducer T2.
• This second transducer T2 captures the acoustic waves emitted and at least partially converts them into electrical energy W which is stored in this second transducer.
• Part of this stored electrical energy can be used to process information D and in particular to transmit to the first transducer T1 information contained and pre-processed in said second transducer T2.
• This energy can also be used to activate at least one actuator A, to read information derived and / or processed by at least one sensor S and to transmit to the first transducer T1 the information acquired by the sensor S.
• a modulation technique of the reflected acoustic wave is used to transmit the information, a technique in which the modulation of the reflected sound wave is modulated by the information to be transmitted.
• the information D of the transducer T2 can be directly transmitted in the form of an alternation of high / low impedance presented to the accesses of this transducer.
• the processing of the received signal will be difficult because of the very wide frequency spectrum occupied by the information.
• the transducer T2 will transmit its data by applying any modulation to any central subcarrier. This central frequency will be that of the filters usually available commercially, for example 455kHz, 10.7MHz, etc.
• a phase, frequency, amplitude modulation, or any combination of these three modulations is performed to modulate the reflected acoustic waves transmitted by the second transducer T2 to the first transducer T1.
• the modulation applied may be of phase, of frequency, of amplitude, such as of the OOK, FSK, PSK, GFSK type, or any mixture of these three modulations.
• the frequency during this excitation can be varied in the form of a rapid frequency variation of the "chirp" type.
• This form of operation promotes significant data rates, to the detriment of the scope of the system and / or its energy consumption.
• FIGS. 2A to 2E illustrate the various configuration possibilities that can be realized on the basis of the method of the invention as well as the power / frequency spectrum of the signal transmitted and reflected in each configuration.
• FIG. 2A represents the basic configuration of the method according to the invention.
• a first transducer T1 transmits acoustic waves W to a second transducer T2 provided with a detector D, which captures them, converts them into electrical energy and at least partially stores said energy in a storage element M of said second transducer T2.
• FIG. 2B represents a second configuration in which the second transducer T2 is associated with a data processing device P.
• the first transducer T1 transmits acoustic waves W to the second transducer T2 which captures them, converts them into electrical energy and partially stores said energy in a storage element M.
• a portion of the stored energy is used to process information in the processing device P and store it in the transducer T2.
• FIG. 2C represents a third configuration in which the transducer T2, associated with an information processing device P, emits reflected waves W R towards the transducer T2.
• FIG 2D The configuration of FIG 2D is identical to that of Figure 2C but, in this case, the reflected waves W R onto the transducer T1 are modulated in phase or frequency or a combination of both.
• FIG. 2E represents a fifth configuration in which the information processing device P is associated with a modulator M and a subcarrier oscillator O for modulating information to be transmitted to the transducer T1 around a subcarrier frequency of reflected waves W R.
• FIGS. 3A to 3C illustrate the variation of the electroacoustic signal in an optimized variant of the method according to the invention.
• the transducer T1 sends acoustic waves for a short period (BURST).
• BURST a short period
• the transducer is oscillated or not according to the information to be transmitted, the latter, in the case of a piezo-acoustic transducer, being transmitted by modifying the electrical impedance presented to it.
• the transducer T1 stops transmitting the transducer T2 will or will not continue to oscillate and thus emit acoustic waves.
• the transducer T2 will be able to store energy and thus release it in the form of acoustic waves once the excitation is ended. If during the excitation, the transducer ports are terminated with a weak impedance, the latter will not be able to store energy and once the excitation is over, it will not transmit any waves.
• FIG. 3A represents the power / frequency acoustic signal emitted by the transducer T1. This signal is in the form of acoustic waves of low BURST oscillation times.
• FIG. 3B represents the acoustic signal present on the electrical ports of the transducer T2 during transmission of a bit 1.
• This transducer T2 oscillates due to the acoustic stimulation provided by the transducer T1 and thus continues to oscillate after the end of the BURST. This remanent oscillation is detected and makes it possible to note that the bit 1 is transmitted.
• FIG. 3C represents the acoustic signal present on the electrical ports of the transducer T2 during the transmission of a bit 0.
• This transducer T2 is strongly damped, for example in the case of a piezoelectric transducer, by shorting its accesses. electric. The very low remanent oscillation is then representative of the transmission of a bit 0.
• Figures 4A and 4B illustrate an embodiment of a device operating on the method of the invention.
• This device 10 intended to be implanted in the human body, consists of two elements which are, on the one hand, a first element called the interrogator 10a comprising a first electroacoustic transducer and shown schematically in FIG.
• the device is arranged to allow bidirectional wireless communication, based on the acoustic wave exchange between the interrogator 10a and the "TAG" 10b.
• the essential feature of this device is to allow the power supply of the "TAG” by means of these same acoustic waves.
• the interrogator 10a plays the role of “master” and manages the communications, while the "TAG” 10b responds to the requests of the interrogator 10a.
• the "tag” 10b is, in this case, associated with at least one sensor and / or actuator 11, whose data it transmits and / or directs the actions.
• the interrogator 10a is preferably located on the periphery of an aqueous medium 30 in which the "TAG" is implanted to be powered and interrogated.
• the interrogator 10a could however be located in the aqueous medium 30 itself.
• the interrogator 10a consists of a power source 100, a control information transmission device 101, a reception unit 102 of the demodulated information received by the interrogator 10a in response to the request.
• the "TAG" 10b illustrated in greater detail in FIG. 4B, is a device that can be passive, that is to say without a source of clean energy.
• the "TAG” 10b is located in the aqueous medium 30 and is for example a device implanted in the human body.
• the use of “TAG” 10b is however not limited to this application and the “TAG” could be implanted, for example, in a chemical reactor.
• the "TAG" 10b can be composed of a variable number of components among which are advantageously an electroacoustic transducer 15 arranged to receive the electroacoustic waves 13 generated by the transducer 12 of the interrogator 10a and retransmit the modulated reflected waves 14 to said interrogator, a power supply and energy management module 16, means arranged to capture said acoustic waves 13 in said second transducer in the form of an information demodulator 17, means arranged to modulate the reflected waves 14 by the second transducer 15 in the form of an information modulator 18, signal processing means 19, and storage means in the form of a memory unit 20, all of these components being associated with a sensor 11 or a set of sensors and / or actuators 11, according to the intended applications.
• an electroacoustic transducer 15 arranged to receive the electroacoustic waves 13 generated by the transducer 12 of the interrogator 10a and retransmit the modulated reflected waves 14 to said interrogator
• a power supply and energy management module 16 means
• the "TAG” 10b may comprise a greater or lesser number of components depending on the intended application. Thus, one could use a “TAG” 10b whose only function is to signal an identity and therefore to validate a presence when interrogated by the interrogator 10a.
• the "TAG” 10b When the "TAG” 10b receives on its electroacoustic transducer waves emitted by the interrogator 10a, it uses it for two purposes, namely a portion of the energy associated with these waves is used to generate its power and the other is returned modulated to the interrogator 10a to transmit information, including information that corresponds to data provided by the sensor or the actuator 11.
• One of the features of the method and device is the use of a single transducer 15 on the side of the "TAG" 10b to perform all the power supply operations of "TAG” 10b and bidirectional communication.
• Another particularity of the method and the device consists in using the modulation of the reflection of the incident acoustic waves 13 generating reflected waves 14 carrying information from the "TAG" 10b, called acoustic "backscattering".
• a mode of operation more adapted to low information rates and having low power consumption is based on the modulation of the damping coefficient of "TAG" 10b.
• the high energy efficiency of the device is based on a match between the transmission frequency and the resonant frequency of the transducers 12 and 15.
• the method of the present invention is not limited to the embodiment described by way of example but allows to consider multiple applications in different fields when a wireless transmission is used.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Biomedical Technology (AREA)
• General Health & Medical Sciences (AREA)
• Biophysics (AREA)
• Pathology (AREA)
• Veterinary Medicine (AREA)
• Heart & Thoracic Surgery (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Surgery (AREA)
• Animal Behavior & Ethology (AREA)
• Physics & Mathematics (AREA)
• Public Health (AREA)
• Signal Processing (AREA)
• Near-Field Transmission Systems (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41395093

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (6)

• 2008
  • 2008-08-29 CH CH01395/08A patent/CH699480A2/fr active IP Right Maintenance
• 2009
  • 2009-08-26 WO PCT/CH2009/000285 patent/WO2010022528A1/fr active Application Filing
  • 2009-08-26 EP EP09775773A patent/EP2345182A1/de not_active Withdrawn

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events