The invention relates to a system for noninvasive measuring of a conductivity in a volume, said system comprising magnetic means arranged as a resonant circuit, said magnetic means being arranged to induce an oscillating magnetic field in said volume, said system further comprising power supply means connectable to said magnetic means, said power supply means being arranged to provide a signal characteristic to a power loss of said resonant circuit upon an application of said magnetic field to said volume.
The invention further relates to a system for monitoring a condition of a user.
The invention still further relates to an alarm system arranged for alarming upon a disorder in a condition of a user.
The invention still further relates to sensing means.
A system as set forth in the opening paragraph is known from WO 99/07281. The known system is arranged to measure an electrical conductivity in a volume under investigation by means of an application of an oscillating magnetic field to said volume. In case the volume under investigation comprises a conductor, eddy currents are generated in said volume according to principles of electromagnetic induction. A power loss due to the eddy currents induced in the conductor is a measure of the conductivity in the volume. An embodiment of the known system is arranged to measure the conductivity in a volume of a living organism. For this purpose the system is provided with at least one conductive coil sized to fit about a body of a person, an oscillator connected to the conductive coil arranged as a resonant circuit, an impedance measuring circuit arranged to provide a signal related to a power loss of said resonant circuit when applied to said living organism. In order to arrange the conductive coil around the body of the person, the known system is provided with a rigid sleeve carrier. The conductors of the known system are attached to said sleeve carrier by means of mechanical connectors. In another embodiment of the known system the conductive coil is sandwiched between an inner sleeve and an outer sleeve in order to protect the person against rigid edges of the outer sleeve.
A disadvantage of the known system is that it accommodates the person in a not very comfortable way. The known system is arranged to fit tightly to the body of the person. The known sleeve carrier is arranged as a rigid body requiring an extra inner sleeve carrier to cushion against various rigid portions of the sleeve. It is therefore uncomfortable for the person to wear such system. Furtheron, the known system is less suitable for purposes of durable application.
It is an object of the invention to provide a system as set forth in the opening paragraph where the usage of the system is improved. In particular, it is a further object of the invention to provide a system for durable patient monitoring.
The system according to the invention is characterized in that the magnetic means are integrated into an insulating fabric carrier. The technical measure of the invention is based on the insight that when the magnetic means comprising resonant circuit are integrated into a fabric carrier a more mechanically flexible system for measuring conductivity in a volume can be produced. For example, for industrial applications a versatile conductivity analyzer can be produced fitting to a plurality of spatial geometries. Preferably, for industrial applications the system according to the invention is integrated into pipe coatings or the like to enable an easy monitoring or control of fluids running in such pipes. Preferably, the fabric is stretchable so that the system according to the invention is adaptable to a variety of pipe diameters.
An embodiment of the system according to the invention is characterized in that the system comprises further magnetic means arranged as a further resonant circuit, said further magnetic means being arranged in a vicinity of a further volume in order to provide a reference signal. In applications where a reference signal is required the system according to the invention is adapted with further magnetic means to induce eddy currents in a further volume yielding a reference signal. For example, the further magnetic means can be located next to the volume under investigation. Alternatively, said further magnetic means can be remotely located, for example to enable a suitable comparison between like structures.
A system for monitoring a condition of a user according to the invention comprises sensing means arranged to be located in a vicinity of a target volume of the user for detecting information representative to the user's condition, said sensing means comprising magnetic means arranged as a resonant circuit, said magnetic means being arranged to induce an oscillating magnetic field in said target volume, the magnetic means being integrated into an insulating fabric carrier, said system further comprising power supply means connectable to said magnetic means, said power supply means being arranged to provide a signal characteristic to a power loss of said resonant circuit upon an application of said oscillating magnetic field to said target volume, said system further comprising detection means actuatable by said sensing means, said detection means being arranged to process said signal in order to derive said information. The system for monitoring a condition of a user according to the invention is particularly suited to enable durable monitoring. Due to the fact that the sensing means of the system according to the invention is integrated into a fabric carrier, for example a piece of clothing, the person can be permanently monitored without inducing any discomfort to that person. Next to this, due to the underlying physical principle, the monitoring can be contactlessly arranged resulting in the absence of skin irritation or other physiological discomfort of the user. The principle of the contactless measurement of conductivity in a living body by means of magnetic induction is known per se from ‘Contactless measurement of thoracic conductivity changes by magnetic induction’, R. Guardo et al Proceedings 19th International Conference, IEEE/EMBS Oct. 30, 1997. Preferably, the system for monitoring according to the invention is integrated into a T-shirt, a brassiere, or any other suitable body-wear. It is also possible to integrate the system for monitoring into a piece of furniture, an invalid chair, a safety belt of a vehicle or the like, etc. Alternatively, the system according to the invention can be integrated into bed sheets enabling a comfortable durable monitoring during user's rest. This embodiment is particularly suited for monitoring of immobilized patients.
An embodiment of the system for monitoring according to the invention is characterized in that the system comprises further sensing means arranged in a vicinity of a further volume in order to provide a reference signal. For purposes of human monitoring is it preferable to provide an additional sensor arranged to interact with the system for monitoring, as for some medical circumstances more than one signal from the body of the user is required. For example, the further sensing means can comprise a temperature meter, a blood pressure meter or any other suitable sensor.
A still further embodiment of the system for monitoring according to the invention is characterized in that the further sensing means comprise further magnetic means arranged as a resonant circuit, said further magnetic means being arranged to induce an oscillating magnetic field in said further volume. Frequently, for purposes of medical monitoring a reference signal from a healthy tissue is desirable. For example, the system according to the invention is suited to monitor a development in the cure of abnormalities, like swollen parts, oedema, injuries or the like. In cases, when such abnormality is present in an extremity, a lateral healthy extremity can provide a reference signal for purposes of comparison. In this case the system for monitoring according to the invention can be integrated into bandages to be put around the volume comprising the abnormality and a corresponding lateral volume. According to this technical measure an individualized information about a progress in the cure can be obtained.
An alarm system arranged for alarming upon a disorder in a condition of a user according to the invention, comprises comprising sensing means arranged to be located in a vicinity of a target volume of the user for detecting information representative to the user's condition, said sensing means comprising magnetic means arranged as a resonant circuit, said magnetic means being arranged to induce an oscillating magnetic field in said target volume, the magnetic means being integrated into an insulating fabric carrier, said alarm system further comprising power supply means connectable to said sensing means, said power supply means being arranged to provide a signal characteristic to a power loss of said resonant circuit upon an application of said oscillating magnetic field to said target volume, said alarm system further comprising detection means actuatable by said sensing means, said detection means being arranged to process said signal in order to derive said information, said alarm system further comprising alarm means actuatable by the detection means, said alarm means being arranged to trigger an alarm signal upon detection of said information by the detection means. Preferably, the alarm system according to the invention comprises transmission means arranged to transmit the alarm signal to a remote station responsive to said alarm signal. For individuals suffering from a life threatening condition it is preferable that the monitoring system targeting said condition is durably worn causing minimum user discomfort. Due to the fact that the sensing means of the alarm system according to the invention are integrated into an insulating fabric, said insulating fabric can easily be integrated into cloths, bed sheets, a furniture piece, a safety belt of a vehicle or the like. In case a life threatening abnormality occurs the alarm means actuate an alarm to warn the bystanders upon an occurrence of said abnormality. When the alarm system according to the invention is integrated into a safety belt, the engine of the vehicle cam be switched off automatically upon an occurrence of a disorder in the condition of the user. The functioning of alarm systems arranged to monitor living organism are known per se and will not be explained in detail.
These and other aspects of the invention will be described with reference to figures.
Number | Date | Country | Kind |
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02080429.0 | Dec 2002 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB03/05338 | 11/21/2003 | WO | 6/15/2005 |