Physiological sensor array

Abstract

A physiological sensor device for attachment to a mammalian subject comprising an output transmitter, at least two physiological sensors each for sensing one of the subject's physiological parameters, and a controller operably in communication with the physiological sensors which controller communicates a signal comprising data representative of both the sensed physiological parameters to the output transmitter which operably transmits the signal to a remote location, wherein the controller comprises a multiplexer which operably switches the data from both the physiological sensors into a serial output signal. In a preferred embodiment, respiration is detected by a bend sensor including an elongate member and an electrical component mounted thereon which electrical component has an electrical property which varies in dependence on the extent of bending of the elongate member. Other parameters such as temperature and full waveform ECG may also be measured.

What we claim is:  
     
         1 . A physiological sensor device for attachment to a mammalian subject comprising an output transmitter, at least two physiological sensors each for sensing one of the subject's physiological parameters, and a controller operably in communication with the physiological sensors which controller communicates a signal comprising data representative of both the sensed physiological parameters to said output transmitter, which operably transmits the signal to a remote location, wherein the controller comprises a multiplexer which operably switches the data from the physiological sensors into a serial output signal.  
     
     
         2 . A physiological sensor device according to    claim 1    wherein the multiplexer is implemented in an application specific integrated circuit (ASIC).  
     
     
         3 . A physiological sensor device according to    claim 2    wherein the output transmitter enables wireless transmission of the signal to the remote location.  
     
     
         4 . A physiological sensor device according to    claim 1    wherein the controller samples an analog signal from the physiological sensors and converts the sampled analog signal into a digital signal for presentation to the output transmitter.  
     
     
         5 . A physiological sensor device according to    claim 1    wherein said at least two physiological sensors comprises at least two from an ECG sensor, a respiration sensor, a motion sensor, and a temperature sensor.  
     
     
         6 . A physiological sensor device according to    claim 5    wherein said at least two physiological sensors comprises a first respiration sensor and a second respiration sensor.  
     
     
         7 . A physiological sensor device according to    claim 6    wherein at least one of the first respiration sensor and second respiration sensor comprises a bend sensor.  
     
     
         8 . A physiological sensor device according to    claim 1    wherein a first physiological sensor operably detects ECG data and the controller operably communicates a signal representative of the ECG data to the output transmitter at a first sampling frequency, and a second physiological sensor operably detects at least one of respiration, motion, and temperature data and operably communicates a signal representative of said at least one data at a second sampling frequency to the output transmitter.  
     
     
         9 . A physiological sensor device according to    claim 8    wherein the first sampling frequency is greater than the second sampling frequency.  
     
     
         10 . A physiological sensor device according to    claim 9    wherein the first sampling frequency is approximately ten times greater than the second sampling frequency.  
     
     
         11 . A physiological sensor device according to    claim 10    wherein the first sampling frequency is on the order of 250 Hz.  
     
     
         12 . A physiological sensor device for attachment to a mammalian subject comprising a bend sensor which comprises an elongate member and an electrical component mounted thereon which electrical component has an electrical property which varies in dependence on the extent of bending of the elongate member, and an electrical monitoring device for detecting variation in the electrical property of the electrical component thereby to determine a physiological parameter of a subject in use.  
     
     
         13 . A physiological sensor device according to    claim 12    wherein the electrical component comprises an elongate resistor superimposed on the elongate member.  
     
     
         14 . A physiological sensor device according to    claim 13    wherein the resistor comprises a track of conductive ink and a series of at least two areas of highly conductive material over the conductive ink thereby to effect a series of individual conductive sensors having a combined resistance less than the track of conductive ink without the areas of highly conductive material.  
     
     
         15 . A physiological sensor device according to    claim 14    wherein the electrically conductive ink forms a substantially U-shaped track.  
     
     
         16 . A physiological sensor device according to    claim 12    wherein the elongate member comprises a flexible substrate.  
     
     
         17 . A physiological sensor device according to    claim 12    which is adapted to attach to a human chest.  
     
     
         18 . A physiological sensor device according to    claim 17    wherein the bend sensor is adapted for application, at least in part, over the pectoral muscle of a subject in use.  
     
     
         19 . A physiological sensor device according to    claim 17    wherein the bend sensor extends between a precordial position to the axilla of a human subject when attached to the subject in use.  
     
     
         20 . A physiological sensor device comprising two electrode sensors operably locatable on a patient, a current generator for driving a current to each of the electrode sensors, and an impedance measuring device which determines variation in the impedance of the electrode sensors when attached to the subject in use, wherein a variation in the motion of the subject is measured as a variation in the impedance at the electrode sensors caused by such motion.  
     
     
         21 . A physiological sensor device according to    claim 20    wherein the current generator comprises a sine wave generator which operably alternately drives each of the two electrode sensors.  
     
     
         22 . A physiological sensor device according to    claim 20    wherein the impedance measuring device comprises a differential amplifier having an input from each of the two electrode sensors.  
     
     
         23 . A physiological sensor device according to    claim 22    wherein a signal output by the differential amplifier passes through a filter and demodulator before being AC coupled to a further stage of amplification.  
     
     
         24 . A physiological sensor device according to    claim 23    wherein the current generator generates an alternating current and the impedance measuring device comprises an anti-aliasing filter.  
     
     
         25 . A physiological sensor device according to    claim 24    wherein the two electrode sensors are drive electrodes in a four electrode sensor arrangement for monitoring subject respiration.  
     
     
         26 . A physiological sensor device according to    claim 20    comprising an output transmitter which enables wireless transmission of an output signal representative of the subject's motion to a remote location.  
     
     
         27 . A portable physiological sensor device comprising a plurality of electrode sensors for use in measuring electrocardiographic data and respiratory data of a subject, wherein at least one of the electrode sensors is used in both the electrocardiographic and respiratory measurements, and an output transmitter responsive to outputs of said electrodes sensors so as to enable wireless transmission of the electrocardiographic data and respiratory data to a remote location.  
     
     
         28 . A physiological sensor device according to    claim 27    wherein a signal from at least one of said plurality of electrode sensors is sampled periodically at a first sampling frequency by an ECG measuring device and periodically at a second sampling frequency by a respiration measuring device.  
     
     
         29 . A physiological sensor device according to    claim 28    wherein the first sampling frequency is greater than the second sampling frequency.  
     
     
         30 . A physiological sensor device according to    claim 29    wherein the first sampling frequency is approximately ten times greater than the second sampling frequency.  
     
     
         31 . A physiological sensor device according to    claim 30    wherein the first sampling frequency is on the order of 250 Hz and the second sampling frequency is on the order of 25 Hz.  
     
     
         32 . A portable physiological sensor device attachable to a mammalian subject in use and comprising two electrode sensors adapted to assist in monitoring at least one of electrocardiographic data, and respiratory data of the subject and further comprising a motion detector which operably monitors the variation in impedance between the two electrode sensors thereby to determine the extent of motion of the patient in use.  
     
     
         33 . A physiological sensor device according to    claim 32    further comprising a first respiration sensor comprising the two electrode sensors and two further electrode sensors, wherein one pair of the two electrode sensors and the two further electrode sensors forms a pair of drive electrodes to which a drive current is operably applied, and the other pair of the two electrode sensors and the further electrode sensors forms a pair of input electrodes to the respiration sensor.  
     
     
         34 . A physiological sensor device according to    claim 33    wherein the first respiration sensor comprises a differential amplifier having an input from each of the input electrodes.  
     
     
         35 . A physiological sensor device according to    claim 32    further comprising a bend sensor which measures respiration.  
     
     
         36 . A physiological sensor device according to    claim 32    further comprising a temperature sensor.  
     
     
         37 . A physiological sensor device according to    claim 32    further comprising a controller which samples an output from electrocardiographic electrode sensors at a first sampling frequency, and another physiological sensor at a second sampling frequency which is less than the first sampling frequency.  
     
     
         38 . A physiological sensor device according to    claim 37    wherein the controller samples an output from at least two of the physiological sensors, other than the electrocardiographic sensor, at substantially the same second sampling frequency.  
     
     
         39 . A physiological sensor device according to    claim 37    wherein the first sampling frequency is approximately ten times the second sampling frequency.  
     
     
         40 . A physiological sensor device for attachment to a mammalian subject comprising a sensor for acquiring physiological data about the subject in use, and an output transmitter which receives a signal representative of the physiological data from the sensor and transmits the signal to a remote location, wherein the output transmitter comprises an inductive element for inductively coupling the output transmitter to a remote receiver at the remote location.  
     
     
         41 . A physiological sensor device according to    claim 40    wherein the output transmitter comprises a reservoir capacitor in parallel with the inductive element.  
     
     
         42 . A physiological sensor device according to    claim 40    wherein the inductive element has first and second ends each of which ends is connected via a pair of switches to signal supply lines within the output transmitter to enable a reversing of the polarity across the inductive element between the supply lines.  
     
     
         43 . A physiological sensor device according to    claim 40    wherein the inductive element comprises a coil which forms part of an H-bridge circuit in the output transmitter.  
     
     
         44 . A physiological sensor device according to    claim 40    wherein the inductive element comprises a rectangular substantially flat coil.  
     
     
         45 . A physiological sensor device for attachment to a mammalian subject, having one or more physiological sensors, an output transmitter for transmitting a signal from the one or more physiological sensors to a remote location, and a memory for storing a serial number for identifying the physiological sensor device which serial number is transmittable by the output transmitter with the signal.  
     
     
         46 . A physiological sensor device according to    claim 45    wherein the serial number is randomly generated.  
     
     
         47 . A physiological sensor device according to    claim 45    comprising a random number generator and a controller for selecting a randomly generated number from the random number generator and storing the selected randomly generated number as the device serial number in the memory.