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: 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: The present invention relates to a device, system and method for determining pulse pressure variation of a subject. To enable more reliably determining pulse pressure variation of a subject the device comprises a signal input (11) configured to obtain an input signal representing a hemodynamic signal of the subject, a processor (12) configured to process the input signal and compute a pulse pressure variation and a signal output (13) configured to output the computed pulse pressure variation. The pulse pressure variation is computed by deriving a pulse height signal from the input signal, deriving a pulse height baseline and a de-trended pulse height signal from the pulse height signal as the ratio between the difference between extrema of the de-trended pulse height signal and the respective value of the pulse height baseline signal, and computing the pulse pressure variation from the de-trended pulse height signal and the pulse height baseline.

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: A wearable gear for holding a physiological sensor for monitoring a subject, such as a pulse oximeter. Said wearable gear being configured to automatically adjust the maximal length such that the predefined tension is obtained regardless of the size of the body part of the subject. The wearable gear comprises a tensioning element having a maximal length, a holding unit for holding the physiological sensor, the wearable gear further comprises a tension mechanism for tensioning the tensioning element to a predefined tension when at least partially around a body part of the subject, wherein the tension mechanism comprises i) a first part comprising a resilient material, and ii) a second part comprising a non-resilient material, and wherein the first part and the second part mechanically cooperate with each other to automatically adjust the maximal length such that the predefined tension is obtained regardless of the size of the body part.

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: The present invention relates to a device for measuring a physiological parameter of a human limb such as peripheral capillary oxygen saturation. The device comprises a body comprising a first body part and a second body part, which are movable relative to each other to define an opening with an adjustable size for receiving the limb therein, and a physiological sensor for interacting with the limb received in the opening, the sensor being attached to the body, wherein the first and second body parts are slidable or twistable relative to each other while at least partially engaging or intersecting each other, or wherein the first and second body parts are configured to form a clip having an L-shaped end section for at least partially enclosing the limb received in the opening, in order to adjust the size of the opening.

Abstract: A wearable gear (100) for holding a physiological sensor for monitoring a subject, such as a pulse oximeter. Said wearable gear being configured to automatically adjust the maximal length such that the predefined tension is obtained regardless of the size of the body part of the subject. The wearable gear comprises a tensioning element (102) having a maximal length, a holding unit for holding the physiological sensor, the wearable gear further comprises a tension mechanism for tensioning the tensioning element to a predefined tension when at least partially around a body part of the subject, wherein the tension mechanism comprises i) a first part comprising a resilient material, and ii) a second part comprising a non-resilient material, and wherein the first part and the second part mechanically cooperate with each other to automatically adjust the maximal length such that the predefined tension is obtained regardless of the size of the body part.

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: A device for supporting determination of return of spontaneous circulation, ROSC, during an associated cardiopulmonary resuscitation, CPR, procedure which is being performed on an associated patient. A sensor is used to sense a physiological signal of the patient. Frequency analysis of the signal is carried out to extract dominant fundamental frequency components in the signal. From this analysis it is possible to determine that there has been a potential ROSC.

Abstract: In a sensor system (12), output signals of at least one PPG sensor (14) are processed to derive a modified pulse amplitude variation (PAV) value, being modified to take account of a baseline variation of the PPG sensor output signal. In particular, the modified PAV is derived through performing a modification step (42) in which either: a baseline variation of the PPG sensor output is derived and combined with a previously derived PAV, or, a PPG sensor output is first processed to perform baseline variation compensation, in advance of then deriving a PAV from the compensated 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.