Abstract: An inductive sensing device comprises first (16) and second (24) loops, the first loop (16) being coupled with a capacitor to form a resonator circuit (20), and the resonator circuit and second loop being coupled via an active buffering component (28). The active buffering component provides voltage to current amplification, and an output of the buffering component drives a current in the second loop. Conductive lines forming each of the first and second loop parts are radially spaced apart.

Abstract: An apparatus (20) for use in inductive sensing includes a loop antenna (26) and a signal generator (24) for driving the antenna, these forming a resonator circuit (22). The resonator circuit is drivable in a drive state in which the antenna is driven at resonance to thereby generate electromagnetic signals. The arrangement further includes a switching means (28) for switchably inhibiting the drive state of the antenna This allows in use controllable switching of the antenna in and out of the drive state to thereby control switching signal generation on and off.

Abstract: A physiological parameter inductive sensing system has a loop resonator which inductively couples with electromagnetic signals emitted from the body. The loop resonator forms part of an oscillator circuit, and negative feedback control is used to control the oscillator circuit, based on a measured oscillation amplitude. Within the feedback control loop, an analog to digital converter is used with a first number of bits (or trits), and successive outputs of the analog to digital converter are combined to derive an output value with a resolution of a second number of bits, greater than the first number of bits (or trits). The feedback control of the amplitude of the oscillator circuit is achieved using the output value.

Abstract: The invention provides for an oral treatment unit, or an assembly of a plurality of oral treatment units, for confining an electromagnetic field having a frequency in the range of 100 kHz to 300 MHz and adapted to be inserted into an oral cavity, which may form part of an oral cleaning device in combination with a base unit, including a first cleaning element coupled to the oral treatment unit. The oral treatment unit further includes a material structure coupled to the oral treatment unit adapted to receive an initial electromagnetic field and output a focused electromagnetic field, wherein the material structure has a passive electromagnetic field focusing function, which focuses the received initial electromagnetic field in the near-field region of the material structure.

Abstract: A system (8) and method is for extracting from sensed induction signals, component signals pertaining to different physiological phenomena in the body. A resonator circuit (10) is oscillated at a certain frequency to generate an alternating electromagnetic field which is applied to a body to be investigated. This field induces secondary eddy currents in the body which interact with the primary magnetic field and alter at least the frequency and amplitude of the resonator circuit oscillating current. These changes in the current characteristics, in particular the frequency and amplitude, are measured and provide first and second input signals. A system (8) or method is provided by embodiments of the invention which is arranged to receive these input signals. A multitude of different composite or fused signals are then generated by the system, each formed from a different linear combination ratio of the two input signals.

Abstract: A switching mechanism is for enabling use of an inductive sensing circuit (16) in association with a portable handheld device (14) having electromagnetic transmission functionality in a manner that avoids harmful interference of the electromagnetic transmissions of the portable device with the subject when medical sensing is being performed. In particular, embodiments provide a controller (12) arranged to control switching between two modes: a first mode in which at least a portion of the transmission functionality of the portable device is deactivated and concurrently the inductive sensing circuit is activated; and a second mode in which the electromagnetic transmission functionality of the portable device is fully activated, and the inductive sensing circuit is deactivated. Thus embodiments provide a means of toggling between two modes, the modes configured to avoid simultaneous inductive sensing and full-power electromagnetic transmission of the portable handheld device.

Abstract: An inductive sensing system (8) is for detecting bleeding (e.g. blood pools) in one or more regions of the body. The system comprises a resonator circuit (10) having at least one antenna (12) which is driven with an oscillatory drive signal to cause generation of electromagnetic signals for application to a body. The signals induce eddy currents in the body which generate secondary EM signals returned from the body. These interact with the resonator circuit by adding an additional component of inductance to the circuit. This inductance component varies depending upon the conductivity of the fluid in which the eddy current is induced. Blood has a different conductivity to other body fluids. The system is configured to detect presence of abnormal accumulations of blood based on the additional inductance component. The system generates a data output representative of the determination.

Abstract: An inductive sensing system (8) has a resonator circuit (10) with an antenna (12) for simultaneously applying electro-magnetic signals to a body and sensing secondary electromagnetic signals returned from the body. The system includes signal sensing means (30) which is configured to detect a measure indicative of an imaginary part of an additional inductance component added to the resonator circuit by the secondary electromagnetic signals but which does not measure the real part. In particular, the signal sensing means may be configured to detect a measure indicative of damping in the resonator circuit (e.g. a damping factor), and comprises no means for detecting any measure indicative of variations in a natural frequency of the resonator circuit.

Abstract: A sensing unit for use in-body comprises a variable impedance circuit for connection to the distal end of a transmission line and reflecting a carrier signal received from the transmission line. The variable impedance circuit comprises a variable impedance component having an impedance which varies non-linearly with applied voltage, a sensor for generating a voltage in response to a stimulus and a voltage bias system for creating a voltage bias for the variable impedance component. The voltage bias sets the operation point of the variable impedance component, such that the voltage changes from the sensor change the impedance of the variable impedance component non-linearly.

Abstract: The present invention relates to a system SY for determining a position of an RF transponder circuit RTC respective an ultrasound emitter unit UEU. The RF transponder circuit RTC emits RF signals that are modulated based on received ultrasound signals that are emitted or reflected by the ultrasound emitter unit UEU. The position of the RF transponder circuit RTC respective the ultrasound emitter unit UEU is determined based on a time difference ?T1 between the emission of an ultrasound signal by the ultrasound emitter unit UEU and the detection by the RF detector unit RFD of a corresponding modulation in the RF signal emitted or reflected by the RF transponder circuit (RTC).

Abstract: The invention provides a magnetic inductive sensing device (30) comprising a loop antenna (10) for inductively coupling with electromagnetic (EM) signals emitted from a medium in response to stimulation of the medium with electromagnetic excitation signals. The device includes an electromagnetic shield (36) element which is arranged such as to intercept electromagnetic signals travelling to or from the antenna. The shield element is formed of conductive material such as to block electrical field components of incident signals but further incorporates a non-conductive gap in the material so as to prevent the formation of eddy currents. A loop of the antenna is broken by an opening, the opening being bridged by a capacitor, and the device comprises a signal processing means which is electrically coupled to the antenna via only a single point of the antenna, located to one side of the opening.

Abstract: The invention provides a magnetic inductive sensing system for sensing electromagnetic signals emitted from a body in response to electromagnetic excitation signals applied to the body. The electromagnetic signals are generated and sensed by the same loop resonator which comprises a single-turn loop antenna and a tuning capacitor. The loop antenna of the resonator and a signal generation means for exciting the resonator to generate excitation signals are together configured so as to optimize the value of a ratio between the radial frequency of the generated electromagnetic excitation signals and a reference frequency of the antenna, where the reference frequency is the frequency for which one wavelength of the generated excitation signals (waves) matches the circumferential length of the antenna. This ratio, which corresponds to a normalized radial frequency of the generated excitation signals, is maintained between a value of 0.025 and 0.50.

Abstract: An apparatus (20) for use in inductive sensing includes a loop antenna (26) and a signal generator (24) for driving the antenna, these forming a resonator circuit (22). The resonator circuit is drivable in a drive state in which the antenna is driven at resonance to thereby generate electromagnetic signals. The arrangement further includes a switching means (28) for switchably inhibiting the drive state of the antenna This allows in use controllable switching of the antenna in and out of the drive state to thereby control switching signal generation on and off.

Abstract: An inductive sensing system (8) is adapted to apply electromagnetic excitation signals into a body, the system comprising a resonator circuit (10) incorporating a loop antenna (12). The system senses signals returned back from the body with the same antenna, based on variation in electrical characteristics of the resonator circuit. The system is configured for separating signals received from different physiological sources within the body. This is performed based on detecting in the resonator circuit electrical characteristics indicative of both a real and an imaginary part of an additional inductance component added to the antenna by received electromagnetic signals. The separating the signals from different physiological sources is based on relative magnitudes of said detected real and imaginary inductance components added to the resonator circuit by the returned signals.

Abstract: An inductive sensing device comprises first (16) and second (24) loops, the first loop (16) being coupled with a capacitor to form a resonator circuit (20), and the resonator circuit and second loop being coupled via an active buffering component (28). The active buffering component provides voltage to current amplification, and an output of the buffering component drives a current in the second loop. Conductive lines forming each of the first and second loop parts are radially spaced apart.

Abstract: According to an aspect there is provided a sensor circuit for use in a body and for communicating measurements of an in body property to a signal analyzer, the sensor circuit comprising a resonant circuit that is responsive to a first radio frequency, RF, field to receive a carrier signal, the resonant circuit having: a first transducer, wherein a first electrical property of the first transducer is dependent on the in-body property, and a second transducer, wherein a second electrical property of the second transducer is dependent on a second pulsed field; wherein the carrier signal received by the resonant circuit is modulated by changes in the first electrical property due to the in-body property and changes in the second electrical property due to pulses in the second pulsed field.

Abstract: An inductive sensing device (22) is for sensing at two different frequencies. The device includes an antenna (24) which comprises at least two loop parts (30, 32), each loop part coupled to a different respective tuning capacitor (36a, 36b) to thereby provide different respective resonant frequencies for the first and second loop parts. The two loop parts are jointly connected to a shared input connection (38) for receiving driving signals for driving both antenna parts. A control means (44) controls a drive circuit (34) to supply the antenna, via the shared input connection, drive signals of each of the frequencies, implementing switching between the two.

Abstract: According to an aspect, there is provided a stethoscope apparatus stethoscope apparatus, the stethoscope apparatus comprising a sound sensor for measuring sounds produced by the breathing of a subject and for outputting a sound signal representing the measured breathing sounds; an antenna for receiving a modulated electromagnetic signal from the body, wherein the modulated electromagnetic signal is modulated by movement of air, fluid and/or tissue in the body; a processing unit that is configured to receive the sound signal from the sound sensor and the modulated electromagnetic signal from the antenna; and normalise the sound signal using the modulated electromagnetic signal.

Abstract: A vital sign monitoring device (10) includes a radio frequency (RF) loop coil (12) that is resonant at both a low frequency and a high frequency that is different from and higher than the low frequency. An annular Faraday shield (18) is arranged to shield the RF loop coil. An oscillator circuit (22) is connected to the both lower and higher oscillation frequency determining RF loop. Readout electronics (24) are connected to measure an electrical response of the RF loop coil energized by the voltage source at both the low frequency and the high frequency and to: extract at least one signal component of the electrical response at the low frequency; extract at least one signal component of the electrical response at the high frequency; and generate vital sign data using both the at least one signal component of the electrical response at the low frequency and the at least one signal component of the electrical response at the high frequency.

Abstract: A measurement circuit for measuring a property in a body comprises: a resonant circuit comprising a first element and a second element, where in at least one of the first element and the second element is configured such that a property thereof is dependent on the property in the body; and a non-linear element arranged to generate intermodulation products when the circuit is driven by an input signal comprising a first component at a first frequency and a second component at a second frequency. A measurement system for measuring a property in a body comprises: a measurement circuit as described above; a driving circuit for providing a driving signal to the measurement circuit, wherein the driving signal comprises a first component at a first frequency and a second component at a second frequency; and an analyzer circuit for analyzing a response of the measurement circuit in order to obtain a measurement of the property.