DE102009040198A1 - Monitoring device for detecting and/or monitoring e.g. water accumulation in lungs in human- or animal body, has signal evaluation units carrying out detection and quantification of fluid accumulates of body from measured data - Google Patents

Abstract

The device has a measuring- and evaluation unit (1) comprising signal generators (2) for generating radar signals e.g. ultra wideband (UWB) pulse signals, pseudo-random digital sequence and continuous frequency modulated signals, with a center frequency between 300 mega hertz and 300 gigahertz. Transmission antennas (4) couple the signals into a body (5), and receiving antennas (8) receive the radar signals reflected at different layers of the body to be measured. Signal evaluation units (11) carry out detection and quantification of fluid accumulation of the body from measured data.

Description

In the medical diagnosis as well as in the care of elderly or physically handicapped people in particular, various issues are related to stored amounts of liquid (in particular water, urine, lymph, but also blood or other fluids) in organs, in biological tissue or generally in different places in the human body.

For example, the amount of urine accumulated in the human bladder may indicate bladder filling and the urinary frequency resulting therefrom, or the amount of fluid in the lung may be indicative of a decompensation that may result from cardiac insufficiency. Other fluid collections also For example, gastric filling, blood accumulation due to internal injuries or other fluid accumulation in human or even animal tissue would be of interest for monitoring.

The device operates on the principle of evaluating reflected radar signals which are coupled into the body via one or more antenna (s) and respectively reflected at the boundaries of different tissue layers. Radar signals are here understood to mean radio signals, which are typically characterized by a center frequency between 300 MHz and 300 GHz, and in the form of (ultra) broadband (UWB) signals such as pulse signals (pulse radar) and pseudo Random digital sequences (pseudo noise radar, PN radar), or in other waveforms such as continuous frequency modulated signals (Frequency Modulated Continuous Wave Radar, FMCW radar) can be used.

In a preferred embodiment, the radar signals are so-called ultra wideband signals (UWB signals), typically with a bandwidth of more than 500 MHz or at least 20% of the center frequency used (see definition / interpretation of UWB signals by the European Conference of Administrations for Post and Telecommunications - CEPT, Electronic Communications Committee - CEPT-ECC). In this UWB technology, it is possible on the one hand to realize very short, differently shaped pulses in the picosecond to nanosecond range (pulse radar) which, due to their shortness, allow relatively accurate spatial resolution, and on the other hand, pseudorandom digital sequences ( PN radar), which allow a correlation between signal and associated reflection and thus also an accurate spatial resolution.

With these radar signals, the material property of the permittivity of dielectric media can then be exploited. In particular, the permittivity (dielectric conductivity) of water is very different from that of adipose tissue or other types of tissue in the human body. The generated radar signals are reflected to different degrees on the boundary layers of different permittive media (Fresnel reflections). In the device these reflections are analyzed and derived from an interpretation of the measured values of the liquid content of the traversed tissue. In this signal analysis, the arrival time of the reflected signals is evaluated and related to a reference measurement additionally evaluated phase and attenuation and other signal parameters of the reflected signal, and physiological parameters (such as ECG, EEG, heart rate, blood pressure or others) can be included ,

In particular, the possibility of integration into a mobile system for continuous monitoring is an advantage of the use of the technology for the detection and quantification of fluid accumulations in the body.

State of the art

In the prior art, the detection or quantification of fluid accumulations in the human body has hitherto been solved by various methods.

The water content in the entire body can be determined for example by a resistance measurement. This principle is implemented by various personal scale manufacturers, such as the company Söhnle. However, the measurements are relatively inaccurate and, above all, unsuitable for water accumulation at a specific site in the body. Frequently used methods for the detection of fluid accumulation in a human or animal body are, on the one hand, non-invasive methods such as ultrasound (sonography), X-rays, magnetic resonance imaging (MRI), as well as invasive methods such as catheterization or implants. The methods mentioned have the disadvantage that each individual measurement means a high expenditure on technical devices.

A method and apparatus for detecting the filling amount of the human bladder based on ultrasound has been disclosed DE 3526164 A1 published in 1985. Another method and apparatus for the general detection of fluids in the human body has been described by the same inventors in 1986 DE 3633080 A1 released. However, both inventions require at least one Component that is used within the body and are therefore (at least partially) associated with the invasive methods. The use of ultrasonic waves to close the amount of the human bladder is in WO 88/03390 Ultrasonic waves represent a different technical approach than the electromagnetic waves of the radar technique.

Radar signals are used in the prior art in various applications, for example for the detection of objects enclosed in a medium such as DE 10 2004 007 315 A1 described. The prior art cited therein, however, is not designed to use the dielectric properties of biological materials to detect fluid buildup, but to allow the detection of objects trapped within a medium.

Another invention which relates to the use of radar signals in the human body is disclosed in US Pat EP 2012139 A1 described. The invention describes a device and a method for monitoring organ movements, but no way to detect and quantify fluid collections. Two further inventions, which have the goal of monitoring organ movements, in particular of the heart, are in US 5766208 and US 5573012 described. Both devices relate to a radar surveillance of the human body for the detection of regular movements of internal organs. Again, however, does not address the detection of fluid accumulation.

A possibility of continuous and mobile feasible monitoring of the stored amount of liquid in the human or animal body is not known to us. The use of radar technology for this purpose is not yet part of the state of the art.

Object of the invention

The object of the invention is therefore to provide a possibility for the non-invasive continuous and mobile monitoring of a fluid accumulation (determined parameters for example: mass, shape or rate of change) in a human or animal organ, in body parts or generally in biological tissue. The monitoring takes place by the signal evaluation of reflected radar signals in a corresponding signal evaluation unit and enables the user, the medical monitoring personnel or the nursing staff to be continuously informed about the amount of stored fluid and to be able to react therapeutically to it.

LIST OF REFERENCE NUMBERS

1

Measuring and evaluation unit

2

signal generator

3

trigger

4

Transmitting antenna (s)

5

Body / Target

6

Emitted signals

7

reflections

8th

Receive antenna (s)

9

amplifier

10

Correlator (s) (mixer)

11

signal evaluation

12

Display and / or communication unit

13

Data storage unit

14

Power supply unit

20

carrying device

21

controls

30

Integrated measurement, evaluation, display and communication unit

example

As described, the device detects and evaluates reflected radar signals, as exemplified in Sketch 1. In the measuring and evaluation unit ( 1 ) the radar signals are transmitted by one or more signal generators (s) ( 2 ), each from a trigger ( 3 ), and then via one or more antennas ( 4 ) in the human body ( 5 ) (or another target object). In the body / target ( 5 ), the emitted signals ( 6 ) is then reflected at the boundary layers between differently permittive media ( 7 ). The resulting reflections are transmitted by one or more receiving antenna (s) ( 8th ), in each case an amplifier ( 9 ), in a correlator / mixer ( 10 ) associated with the output pulse, and then in a signal evaluation unit ( 11 ) processed and interpreted. A display and / or communication unit ( 12 ) can then either display the evaluated signals directly, or transmit them by wire or wireless, so that the results can be reused. A data storage unit ( 13 ) can save the data for later further evaluations. The energy supply of all units is provided by a power supply unit ( 14 ), for example by an accumulator, a power supply or an energy harvesting device, which gains energy from sources such as vibrations or temperature differences in the environment.

Also, an embodiment of the invention in which the measuring and evaluation unit only a single antenna, which is a combined transmitting and receiving antenna contains, or an embodiment of the invention with integrated measuring, evaluation, display and / or communication and Data storage and power supply unit, possible.

One embodiment is a wearable device that can continuously monitor fluid accumulation in the human body (Sketch 2). In the example, the measuring and evaluation unit ( 20 ) as well as the display and / or communication unit ( 21 ) by a carrying device, which may for example be designed as abdominal or chest belt ( 20 ), on the body ( 5 ) is held above the fluid collection to be measured (eg bladder, lung, stomach, etc.) and the user or the nursing staff on site or elsewhere (telemedical monitoring, electronic patient record) is constantly informed about the current amount of fluid. The control of the device can be achieved via different operating elements ( 21 ) or as part of a telemonitoring concept from a remote monitoring station.

Another exemplary embodiment is a measuring and evaluation unit integrated into a mobile telephone (sketch 3). In this embodiment, the device is in a mobile phone or in a similar mobile terminal ( 30 ) integrated. This embodiment allows the measurement of water accumulation anywhere in the body ( 5 ) by manually attaching the mobile device. The measured data can then be directly displayed and output and / or stored locally and / or communicated and integrated into a telemonitoring concept.

One possible application of these embodiments is in the care of paraplegic people who no longer have a full bladder sensation and therefore rely on a catheter. Continuous monitoring of the bladder volume thus makes life easier. Another possible application is in the diagnosis of heart failure patients in whom a build-up of water in the lungs can be diagnosed as a sign of decompensation. The continuous use of the device in this field of application makes it possible to detect this accumulation of fluid in an early and greatly simplified manner compared to the measuring methods of the prior art and thus to spare the patient concerned hospital visits. Heart failure patients are enabled to undergo continuous self-monitoring or follow-up, which means fewer inpatient hospital stays are required.

The evaluation of the signals can be carried out in all application examples with the inclusion of physiological parameters.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3526164 A1 [0009]
• DE 3633080 A1 [0009]
• WO 88/03390 [0009]
• DE 102004007315 A1 [0010]
• EP 2012139 A1 [0011]
• US 5766208 [0011]
• US 5573012 [0011]

Claims (16)

Monitoring device for detecting and / or monitoring fluid collections in the human or animal body, for example water, urine or blood, with measuring and evaluation unit ( 1 ), characterized in that the measuring and evaluation unit one or more signal generator (s) ( 2 ) generating radar signals having a center frequency between 300 MHz and 300 GHz, one or more transmitting antenna (s) ( 4 ), via which these signals are coupled into the body ( 6 ), one or more receiving antenna (s) ( 8th ) covering the different layers of the body / target to be measured ( 5 ) reflected radar signals ( 7 ) receives, as well as one or more signal evaluation unit (s) ( 11 ), which makes / make the detection and quantification of a fluid accumulation from the measured data has. Monitoring device according to claim 1, characterized in that the radar signals ( 6 ) are (ultra-) broadband pulse signals (UWB pulses) with a length in the range of a few pico to several hundred nanoseconds (pulse radar). Monitoring device according to claim 2, characterized in that the radar signals used ( 6 ) correspond to the current interpretation of Ultra Broadband Signals (UWB signals) (see definition / interpretation by the European Conference of Postal and Telecommunications Administrations - CEPT, Electronic Communications Committee - CEPT-ECC) and typically a bandwidth of at least 500 MHz or more than 20% of the center frequency used. Monitoring device according to claim 1, 2 or 3, characterized in that the radar signals ( 6 ) are generated by pseudo-random digital sequences and evaluated via a correlation function (PN radar). Monitoring device according to one or more of the preceding claims, characterized in that the execution allows a mobile application. Monitoring device according to one or more of the preceding claims, characterized in that the time interval between two measurements be very short (a few milliseconds), and the monitoring of the amount of liquid can thus be carried out quasi-continuously. Monitoring device according to one or more of the preceding claims, characterized in that it comprises a display and / or communication unit ( 12 ) which displays / outputs the determined data directly to the user (for example via a display or an acoustic or tactile feedback) or communicates by wire or wireless to a spatially separated central evaluation point (for example PC application or remote telemonitoring monitoring device). Monitoring device according to one or more of the preceding claims, characterized in that the transmission ( 4 ) and receiving antenna (s) ( 8th ) for transmitting and receiving the radar signals, as a combined transmitting and receiving antenna (s) is / are performed and the distribution of the signals, for example via a circulator. Monitoring device according to one or more of the preceding claims, characterized in that their technical realization takes place wholly or partly as a stationary system. Monitoring device according to one or more of the preceding claims, characterized in that its technical realization takes place wholly or partly as a mobile, portable and easily applied to the body system, for example, integrated into a mobile phone or PDA ( 30 ) or as a dedicated liquid monitoring system similar in shape and type. Monitoring device according to one or more of the preceding claims, characterized in that its technical realization wholly or partly in a carrying device ( 20 ) or integrated into a garment. Monitoring device according to one or more of the preceding claims, characterized in that the signal evaluation unit ( 12 ) evaluates the received reflected signals by a signal analysis of, for example, phase or amplitude or other signal characteristics. Monitoring device according to one or more of the preceding claims, characterized in that the signal evaluation unit ( 12 ) takes into account additional physiological parameters such as ECG, EEG, heart rate or blood pressure when analyzing the reflections. Monitoring device according to one or more of the preceding claims, characterized in that it comprises a data storage unit ( 13 ), which can store the recorded data locally and thus enable long-term or trend analysis (prediction). Monitoring device according to one or more of the preceding claims, characterized in that it comprises a power supply unit ( 14 ), for example an accumulator, a power supply or an energy harvesting device, by which it is supplied with power wirelessly or by wire. Monitoring device according to one or more of the preceding claims, characterized in that a part of its basic functionality, in particular the measuring and evaluation unit ( 1 ), is satisfied by a standard UWB communication chip.

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