Abstract: Apparatus for monitoring an ECG signal comprises a first body wearable part 1 for receiving a physiological signal and comprising processing means, a memory, and a wireless transceiver, the memory storing a plurality of signal segment templates. The processing means is arranged to compare and match segments of the physiological signal to the stored template. The apparatus further comprises a second part 4 comprising a wireless transceiver and processing means, the processing means being arranged to generate and/or modify signal segment templates, and to cause said transceiver of the second part to transmit generated or modified templates to the first part.

Abstract: A method of associating a wireless sensor device to a user profile in a physiological sensor system, the system comprising a computer records system, at least one base station and a plurality of wireless sensor devices, each of the sensor devices being in contact with a user, the method comprising selecting or defining a user profile on the computer records system for a given user and monitoring signals received at the base station from respective wireless sensor devices. The method further comprises identifying a signal having a response that is characteristic of a pre-defined physiological act and associating the sensor device from which the identified signal is received with the user profile.

Abstract: A receiver front end receives a local frequency reference signal and a Frequency Shift Keying modulated signal comprising a synchronisation sequence, and downconverts the Frequency Shift Keying modulated signal to provide baseband in-phase and quadrature signals. A pulse generator receives the in-phase and quadrature signals, generates an in-phase pulse signal ILEAD comprising pulses aligned with edges of the baseband in-phase and quadrature signals when the baseband in-phase signal leads the baseband quadrature signal, and generates a quadrature pulse signal QLEAD comprising pulses aligned with edges of the baseband quadrature and in-phase signals when the baseband quadrature signal leads the baseband in-phase signal. A frequency corrector receives the in-phase and quadrature pulse signals during receipt of the synchronisation sequence, compares the pulse signals to a target, and generates a control signal for controlling the local signal generator in dependence upon the result of the comparison.

Abstract: A method of transmitting a data sequence between a sender and a receiver over a wireless link. The method comprises, at the sender, segmenting the data sequence into a plurality of data segments and, for each segment, constructing a frame containing as payload the data segment, transmitting the frame across the wireless link, and receiving an acknowledgement or non-acknowledgement from said receiver for the frame, and only upon receipt of such acknowledgement or non-acknowledgement, retransmitting the frame or transmitting a further frame containing as payload the next data segment.

Abstract: A circuit for operating an amperometric sensor having a reference electrode, a counter electrode and a work electrode. The circuit comprises an amplifier having a positive input and a negative input and an output. The positive input is coupled to a reference voltage source, and the negative input and the output are coupled together via a negative feedback loop. The circuit includes means for coupling the amperometric sensor into said negative feedback loop of the amplifier wherein, in a first configuration, the counter electrode is coupled to said output and the reference electrode is coupled to said negative input and, in a second configuration, the work electrode is coupled to said output and the reference electrode is coupled to said negative input.

Abstract: An integrated circuit having a plurality of circuit blocks, each block having one or more positive voltage supply pads, one or more negative voltage supply pads, and one or more signal pads. The integrated circuit further comprises an electrostatic protection circuit comprising a first electrostatic discharge protection rail for connection to a positive voltage supply point, a second electrostatic discharge protection rail for connection to a negative voltage supply point, and first protection circuitry coupling each said signal pad to both said first and second electrostatic discharge protection rails, the first protection circuitry being configured to provide a conduction path to one of the first and second rings in the event of an excessive voltage being present on one of said signal pads.

Abstract: A multiplier is provided, for example, for use as a mixer in a modulator of a radio frequency transmitter. The multiplier multiplies a first alternating signal of constant amplitude by a second signal, for example, in the form of a carrier wave from a local oscillator. The multiplier comprises a transconductance stage for converting the first signal to a differential output current and a current switching stage for switching the differential output current in accordance with the second signal. The transconductance stage comprises a plurality of offset pairs of transistors, whose inputs and outputs are connected in parallel. The switching stage comprises cross-coupled pairs of transistors which, together with the transconductance stage, form a Gilbert cell. The relative gains of the transistors of each offset pair are such that a minimum in the third harmonic distortion characteristic of the multiplier occurs substantially at the amplitude of the first signal.

Abstract: A healthcare monitoring system includes a plurality of patient wearable sensor devices for the purpose of monitoring physiological data, each sensor device including a radio frequency transceiver. A plurality of base stations are provided at respective fixed locations within a healthcare facility, each base station including a radio frequency transceiver for communicating with one or more of the sensor devices for the purpose of receiving monitored physiological data. A central server is coupled to the base stations for the purpose of receiving and recording monitored physiological data. Each sensor device is arranged in use to attach to a first base station that is within range, and to attach to a second, different base station that is within range when contact with the first base station is lost, attachment of the sensor device to a base station being registered with the central server.

Abstract: A receiver front end receives a local frequency reference signal and a Frequency Shift Keying modulated signal comprising a synchronisation sequence, and downconverts the Frequency Shift Keying modulated signal to provide baseband in-phase and quadrature signals. A pulse generator receives the in-phase and quadrature signals, and generates an in-phase pulse signal ILEAD comprising pulses aligned with edges of the baseband in-phase and quadrature signals when the baseband in-phase signal leads the baseband quadrature signal, and generates a quadrature pulse signal QLEAD comprising pulses aligned with edges of the baseband quadrature and in-phase signals when the baseband quadrature signal leads the baseband in-phase signal. A frequency corrector receives said in-phase and quadrature pulse signals during receipt of said synchronisation sequence, compares the pulse signals to a target, generates a control signal for controlling the local signal generator in dependence upon the result of the comparison.

Abstract: A method of transmitting a data sequence between a sender and a receiver over a wireless link. The method comprises, at the sender, segmenting the data sequence into a plurality of data segments and, for each segment, constructing a frame containing as payload the data segment, transmitting the frame across the wireless link, and receiving an acknowledgement or non-acknowledgement from said receiver for the frame, and only upon receipt of such acknowledgement or non-acknowledgement, retransmitting the frame or transmitting a further frame containing as payload the next data segment.

Abstract: An integrated circuit having a plurality of circuit blocks, each block having one or more positive voltage supply pads, one or more negative voltage supply pads, and one or more signal pads. The integrated circuit further comprises an electrostatic protection circuit comprising a first electrostatic discharge protection rail for connection to a positive voltage supply point, a second electrostatic discharge protection rail for connection to a negative voltage supply point, and first protection circuitry coupling each said signal pad to both said first and second electrostatic discharge protection rails, the first protection circuitry being configured to provide a conduction path to one of the first and second rings in the event of an excessive voltage being present on one of said signal pads.

Abstract: An electric circuit suitable for use as a radio receiver or part of a radio receiver, the electric circuit comprising amplification means, frequency mixer means, and filter means, wherein the frequency mixer mans is configurable to down-convert a wanted component of the amplified input signal to one of at least two intermediate frequency bands, and the filter means is dynamically reconfigurable between a first filter configuration which provides a first operating mode, and a second filter configuration which provides a second operating mode.

Abstract: A floating gate MOS transistor comprises one or more control gates, an active channel, and at least one floating gate disposed between the control gate(s) and the active channel. First and second non-linear resistances couple the floating gate to first and second control voltage sources respectively, the non-linear resistances forming a voltage divider network which sets the operating voltage of the floating gate.

Abstract: A circuit comprising a digital processor, analogue processing means, a digital to analogue converter for converting digital values output from the digital processor into analogue values which are processed by the analogue processing means, and an analogue to digital converter for converting resulting analogue values into digital values for input to the digital processor, wherein the analogue processing means comprises one or more analogue processors, and the circuit is dynamically reconfigurable under the control of the digital processor, such that analogue values are processed according to a first function by the analogue processing means, and following reconfiguration, analogue values are processed according to a second function by the analogue processing means.