DE102017002334A1 - Time-resolved measurement of parameters of the heart function by autonomously adjustable measuring ranges, such as e.g. Cardiac output, blood pressure, heart pulse, pulse wave transit time, pulse wave variability, respiratory rate ... - Google Patents

Abstract

Apparatus for the mobile measurement of characteristics of the cardiovascular system, such as cardiac output, blood pressure, cardiac output, pulse wave transit time, pulse wave velocity, pulse wave variability, respiratory rate and arterial elasticity, on an object, namely a human or animal body, using one or more Pressure sensors, letter K, for measuring the energetic pulse wave.

Description

The invention relates to the measurement of the cardiac output of an object, namely a human or animal body, using pressure sensors for temporally resolved measurement of the energetic pulse wave. The measurement of time-resolved changes in cardiac output requires the measurement of many other characteristics of the cardiovascular system. These include the time change of blood pressure, the pulse wave transit time, respiratory rate and heart rate. The invention enables a temporal resolution in the millisecond range. Thus, for example, the blood pressure is not only measurable in the form of systolic and diastolic blood pressure, but also as a continuous wave, which indicates at any time, even within a single heart pulse, the current pressure on the arteries.

This temporal accuracy paired with the possibility of measuring at various points of the body allows the determination of the individual characteristics of the cardiovascular system.

The determination of the parameters of the cardiovascular system is based on the analysis of the measurements of the pulsating pressure wave from the heart in the arteries.

Since an accuracy or a data acquisition rate of the pulsating pressure wave of one millisecond is achieved, the measured value wave of the pulsating pressure wave can be examined for minimas and maximas. The values of these minimas and maximas, when handled correctly, will be the values for the value of the diastolic and systolic portions of the conventional blood pressure value, respectively. In addition, the current heart pulse can be determined from the time interval of the minimas or the maximas relative to one another, specifically from pulse to pulse, which allows the calculation of the pulse wave variability. The simultaneous determination of cardiac pulse and blood pressure allows the calculation of cardiac output.

Since arrangements according to the invention can also have a plurality of pressure sensors, measurements of the pulse wave transit time are possible by measurements at different measuring points.

Moreover, the temporal resolution of the data acquisition rate also means that the distance of the sensors from one another need not be particularly great, and thus a sensor unit with a plurality of sensors can be used, which can only be perceived by the user as a single unit. This allows a very simple and rapid measurement of these parameters, which require lengthy preparation times and a large number of different sensors with measuring devices used today.

Differentiation to other patents Differentiation to EP 2337493 B1

The patent EP 2337493 B1 describes a continuous blood pressure measurement by means of sensors based on the piezoelectric effect.

It describes the measurement of blood pressure through a bracelet.

As described in the patent P 2337493 B1, two different sensor types must be used in an inventive design. A sensor for recording the actual blood pressure and a band sensor for determining the contact pressure of the bracelet.

The measurement is carried out by gradually tightening or loosening the bracelet until the tape sensor measures an optimal contact pressure and is called user calibration. It must first be set to a fixed state and then a too loose state. From these values measured at these states, a correction function is determined which corrects the measured values in a middle state. During this user calibration, the person to be examined should move as little as possible and have a uniform blood pressure.

Subsequently, an external calibration becomes necessary. For this purpose, a recognized measuring method for determining the blood pressure, e.g. the measurement with the oscillation method is needed. Again, the blood pressure of the person to be examined should not change or equal to the previous calibration.

For a more accurate calibration, the two calibration steps must be repeated, with a higher blood pressure in the person to be examined against.

In addition to the pressure or band sensor, an acceleration sensor is available, this is used to check whether the calibrations are done at rest and during the continuous measurement of whether oscillations of, for example, the arms done.

The data of all sensors are determined with a sampling rate of 40 Hz.

delimitation:

The principal method of measurement described in this patent is similar, but there are fundamental differences that allow a simpler and more flexible measurement.

As will be described hereinafter, measurement of the blood pressure according to the inventive arrangement is performed as follows. The pressure-sensitive sensor is applied at a suitable location, e.g. be a spot on the wrist, and then slowly pressed. The pressing or the setting of the back pressure can be done either by human action or by an autonomous actuator. At the same time, measured values of the pressure resulting from the pulsating pressure wave of the artery are recorded. As the back pressure increases, so do the Maximas in the wave of readings. From a certain back pressure no further increase of the Maximas can be seen. The pressure values of these Maximas are the value of the systolic portion of the blood pressure. At the smallest backpressure, where no further increase in the maxima of the wave of readings can be seen, the pressure values of the minimas of the wave of the readings correspond to the diastolic portion of the blood pressure.

If this back pressure persists, a continuous measurement can be made.

The methodology shows that unlike the patent EP 2337493 B1 no calibrations are necessary and that a faster and more user-friendly measurement is possible. Calibrations presented here are not to be performed by the user but are automated or produced.

In the patent EP 2337493 B1 a data collection rate of 40 Hz is specified. This is sufficient to collect data on blood pressure and cardiac output, for data which can be collected with an inventive arrangement according to this patent, this temporal resolution is not sufficient. Data that can only be obtained with an inventive arrangement according to this patent are the pulse wave transit time (by examining the waveform of a single pulse with respect to the reflection wave or by measuring at different locations on the body), the pulse wave velocity, the pulse wave variability, and the cardiac output.

Sensors based on the piezoelectric effect, such as the pressure sensors used in patent EP 2337493 B1 to react to other physical quantities. This is probably the main argument, which is why in the patent EP 2337493 B1 the use of an acceleration sensor is cited. The data of the acceleration sensor can be used to compensate for incorrect data due to movements and therefore occurring acceleration forces of the pressure sensors.

In the case of the use of film pressure sensors described as being advantageous in this patent, there is no such influence by acceleration forces.

The reason for using an acceleration sensor in this patent is based on the fact that the value of the blood pressure at different points in the body and also at different heights to the hydrostatic point of difference (HIP) (changes in the height of a measuring point to HIP is eg Arm movement triggered.) To be measured. Only by knowing the current altitude to the HIP can a value for the blood pressure at the HIP also be determined in the movement, although the measuring point may be e.g. located on the arm.

In the patent EP 2337493 B1 If several sensors are used, the reason for this is not apparent. For inventive arrangements according to this patent, several sensors can be used. When using a sensor array, it is possible to choose the sensor which is optimally located over an artery, this increases the user-friendliness, since a time-consuming placement of the sensor module is not necessary. Furthermore, a sensor array can be used to determine the pulse transit time at the measuring point by evaluating the measured values of the pulsating pressure wave from at least two sensors.

In another inventive arrangement according to this patent, a plurality of sensors may be organized separately from each other so that one sensor may be mounted near the heart, for example, and another may be attached to the wrist at a suitable location, for example. The evaluation of the measured value wave of the pulsating pressure wave enables the calculation of the pulse wave transit time from the heart to the wrist.

The author of this patent is aware that the measurement methodology used in patent EP 2337493 B1 described may lead to extremely accurate readings. An extended to a higher data acquisition rate inventive arrangement, similar to the description in the patent EP 2337493 B1 , represents a revolution especially for the medical sector, which is not so much the cost and energy efficiency in the foreground.

In the invention described in this patent, various types of pressure sensors can be used, including sensors that operate on the basis of the piezoelectric effect.

The in the patent EP 2337493 B1 necessary calibrations described are not necessary in inventive arrangements according to this patent. In addition, a significantly higher data acquisition rate, preferably 1000 Hz, is possible. Thus, the invention represents this revolution.

Basic structure of the invention

The invention comes with a minimum sensor size and requires no invasive intervention in the body.

Using pressure sensors that measure by force, the sensor can be placed directly on the skin, see 1 Letter O. The sensor size must be no larger than a cherry stone, or 5mm in diameter, to perform a blood pressure measurement on the skin.

The operation of the invention is based on the operation of the classical method for blood pressure measurement, the Riva Rocci method. However, this extends the temporal resolution of blood pressure value determination and can therefore also be used for continuous long-term measurement. In addition, the measurement is less painful due to the small sensor size. This is especially advantageous in a continuous long-term measurement.

The pressure sensor and the necessary evaluation unit can be used alone.

Advantageously, however, the pressure sensor with evaluation, energy unit and radio unit is integrated in a garment or designed as an essay.

Possible garments are bracelets, footbands, shoes, rings or ear clips. Furthermore, the inventive arrangement can also be attached to the body with the help of specially made straps.

If the inventive arrangement designed as an essay this can be attached by attaching to a conventional bracelet or, for example, by attaching or inserting the shoe / tongue (back of the foot) on the body.

Advantageously, the inventive arrangement can also be extended by an actuator which can exert a base pressure on the sensor unit. However, the inventive arrangement can also be operated without an actuator.

As further described in this specification, the inventive arrangement must be mounted on the body so that pressure can be applied to the body by the sensor unit.

In particular, places on the body are advantageous in which the pulse of the arterial system is noticeable. These are, for example, under other positions on the wrists or positions on the backs of the feet.

Requirements and selection of sensors

State of the sensor technology

Theoretically, some kind of technology, such as an FSR sensor (Force Sensing Resistor), can be used to measure blood pressure. This technology is described in a patent by Interlink and in a variety of publications by the company Interlink accessible to the skilled person on the Internet. This described pressure sensor is also produced by the company Interlink and has been commercially available for many years. The pressure sensor is available in different sizes. The FSR sensors listed below function by applying an electrically conductive paste or substance to the carrier material but above the electrical leads.

In most cases, however, a pressure-sensitive and resistance-conductive film is used, which is applied with a carrier layer to the electrical conductor tracks and connected to each other by means of double-sided adhesive layer. The person skilled in the necessary information is available. However, the offerings of the company "Interlink" to FSR sensors are limited to a pressure-sensitive film that changes their resistance conductivity when exposed to pressures or weights.

All of today's commercial pressure sensors are not suitable in their nature and performance for use in measuring cardiac output. The pressure sensors are unsuitable on the skin of a human or animal body to measure the cardiac output mobile and without effort for the user. Furthermore, today's commercial pressure sensors have no long-term stability and therefore lose their measuring accuracy after a short time (even within a few seconds), which necessitates calibration.

FSR sensor technology has not been developed for accurate and consistent pressure measurement. Strong fluctuations in the continuous recording of measured values lead to unfitness in the measurement of weight and thus also the medical application.

A calibration of the conventional sensors can be done by loading the sensor with a known pressure. This may, for example, be a motorized bracelet which sets a known pressure by defined contraction. This pressure of the bracelet may e.g. by strain gauges (these are not usable for the actual measurement because the temporal resolution is too low) can be determined.

However, the calibration with the aid of a vibration motor is advantageous. This can be applied to the sensor by means of a suitable electrical circuit, as is known to the person skilled in the art, with a defined pressure and thus carry out a calibration.

Also, the design of existing pressure sensors for the use of pressure sensors for a mobile cardiac output measurement is unsuitable. This also applies to the existing FSR sensors.

The invention requires smaller and more specific in their application for blood pressure measurement designs as a solution. Nevertheless, the basic principle of FSR sensors, for example from the company "Interlink", can be used.

Requirements for a sensor for cardiac output measurement

• • Flexible Form, damit der Sensor sich an die jeweilige Messstelle am Körper anpassen kann.
• • Weiche Ausgestaltung des Sensors, um Verletzungen vorzubeugen.
• • Eine Form, die sich den Körper anpasst, um eine möglichst große Bedeckung des Sensors zu erreichen.
• • Eine kleine Sensorgröße, vorteilhafterweise mit einem Durchmesser von 5mm. Jedoch sind auch größer und kleinere Größen möglich.
• • Eine gleichbleibende Qualität der Messung, möglichst ohne Kalibrierung, vorweisen. Eine kontinuierliche Messung über zwei Wochen hinweg muss mindestens gewährleistet werden.
• • Ein Messbereich, der den zu erwartenden Blutdruckbereich abdeckt. Dieser sollte mindestens von 40mmHg bis 300mmHg sein.
• • Eine Druck-Auflösung von 0.5mmHg oder kleiner vorweisen.
• • Eine Zeit-Auflösung von 1ms oder kleiner vorweisen.
• • Der Sensor sollte das Signal so wenig wie möglich dämpfen.
• • Wetter- und feuchtigkeitsfest sein. Dies umfasst auch die Resistenz gegen Schweiß.
• • Die Messwertermittlung muss mit geringen Energiebedarf möglich sein, um eine mobile Messung z.B. Batteriebetrieben zu ermöglichen
• • Die Messwertermittlung muss mit wenigen weiteren Komponenten neben dem eigentlichen Sensor möglich sein, um eine kleine Bauform zu ermöglichen.

Advantageously, at least the following requirements for the sensor must be met:

• • Flexible shape so that the sensor can adapt to the respective measuring point on the body.
• • Soft design of the sensor to prevent injury.
• • A shape that adapts to the body to maximize coverage of the sensor.
• • A small sensor size, advantageously with a diameter of 5mm. However, larger and smaller sizes are possible.
• • Have a consistent quality of the measurement, if possible without calibration. A continuous measurement over two weeks must at least be guaranteed.
• • A measuring range covering the expected blood pressure range. This should be at least from 40mmHg to 300mmHg.
• • Have a print resolution of 0.5mmHg or smaller.
• • Have a time resolution of 1ms or less.
• • The sensor should attenuate the signal as little as possible.
• • Weather and moisture proof. This includes resistance to sweat.
• • The measured value determination must be possible with low energy consumption in order to enable a mobile measurement eg battery operations
• • The measured value determination must be possible with a few other components in addition to the actual sensor to allow a small design.

Today available pressure sensors can not meet all requirements. The Interlink FSR sensors already meet some requirements or can be improved by small modifications.

The FSR sensors were suitable as a starting point for the mobile continuous measurement of cardiac output. The principle of FSR sensors requires a minimum of energy.

However, the requirements for measuring range and for printing resolution and above all to the consistent quality are not met, or can not be achieved by modifications.

In particular, the requirement for the measuring range represents a particular challenge. The measuring range must be relatively large and the measured value fluctuates rapidly over large ranges of the necessary total measuring range.

Therefore, the inventive arrangement uses new types of sensors, which will be presented below.

Advantageous sensors for cardiac output measurement

Advantageously, an SRS sensor (switchable resistive sensor) can be used to measure cardiac output. This sensor type has several measuring ranges (at least two measuring ranges). This makes it possible to cover a large measuring range. Furthermore, the individual measuring ranges are independent of each other, i. the measurement of the blood pressure is possible at the same time in different accuracies in different measuring ranges.

In comparison to other sensor types, for example FSR sensors (Force Sensing Resistor) from Interlink or piezoelectric sensors, a large total measuring range can be recorded. This is particularly advantageous since during the movement of the body, the time-varying blood pressure signal due to the height of the sensor, measuring point, for example. At the extremities, varies to the HIP. The variation of the blood pressure signal can have several causes. In addition to the movement of the body, for example, temperature changes or medication can lead to a sudden change in the blood pressure signal.

Since the sensor detects the signal of the pulsating pressure wave with several measuring ranges simultaneously, the best measuring range can be used without switching over the readout electronics.

Another advantageous sensor is the VRS (Variable Resitive Sensor). This is a sensor whose measuring range can be changed by electrical induction. Thus, even with this type of sensor, a large measuring range can be covered. When using this sensor type, there are basically two measuring methods. On the one hand, a fixed measuring range can be set, which is only changed if necessary, the signal of the pulsating pressure wave is measured directly. On the other hand, the pressure can also be measured indirectly by changing the electrical induction to range selection until a given signal results. The actual measured value here is the setting of the electrical induction. The direct measurement allows a faster generation of measured values, whereas the indirect measurement allows more accurate measurements.

Adjustment of sensors

The sensors presented here are based on the fact that a polymer which is resistant to resistance is forced onto an arrangement of exposed printed conductors by the application of force.

Therefore, for the application both the arrangement of the tracks and the properties of the polymer must be adjusted.

With the SRS sensor, several tracks mesh with each other. The number of Leitbahnnetzt is given by the number of measuring ranges and is given by the number of measuring ranges plus one. The VRS uses only two trace networks.

The adaptation of the interconnect networks to the measurement requirements requires an adaptation of the distances between the interconnects to each other, the width of the interconnects to each other and the area coverage of the interconnects. Furthermore, an adjustment can be made by targeted painting of individual areas.

For a quick and inexpensive adjustment of these parameters, it has proven to be advantageous to insert a further non-conductive polymer layer.

The procedure of setting the tracks is thus carried out by first a sensor is made, which corresponds to experience about the requirements. Now, a further polymer layer is inserted between the interconnects and the resistance conductive polymer. This further polymer layer is not conductive.

The non-conductive polymer layer is provided with holes, stripes or other omissions. Now, the area fraction and the exact expression of the omissions is varied until the desired measurement range is found. This is especially advantageous since this additional polymer layer is cost-effective for one and on the other hand can be quickly replaced.

If an optimal area ratio is found, a coating corresponding to the non-conductive polymer layer is used during the production of the sensors.

The adjustment or the optimization of the polymer requires the exact knowledge of the circumstances of the measurement.

In the case of cardiac output measurement, this means that the sensor is used on the skin and forces in the range 1-10N occur. In addition, a high data acquisition rate of at least 1000 values per second should be possible.

The requirement that the measurement should be possible on the skin means that a measurement on a non-smooth surface must be possible. As a result, a flexible polymer must be used. Advantageously, silicone is used for this purpose.

The requirement of the measuring range and the high data acquisition rate mean that the polymer has to exert a certain counterforce. This is possible in two ways. On the one hand, the Shore hardness of the silicone can be adjusted, on the other hand, the design can be suitably chosen to allow the required counterforce.

You can also set both properties separately. For this purpose, a design that can meet the required counterforce, with a higher Shore hardness compared produced. This design is larger than the surface of the conductor networks. In this design, at the location that comes into contact with the traces during use, there is an area to which another silicone may be applied with a different, lower Shore Hardness. This applied silicone is called a functional polymer.

In addition, the functional polymer can also be made with a location-dependent variable Shore hardness. This is done by adding the functional polymer e.g. Layer by layer is applied and from layer to layer a different Shore hardness is used. Another possibility of variable Shore hardness is the use of special UV-curable polymers. These polymers change their Shore hardness when exposed to UV light. Depending on the exposure time, a Shore hardness can be set. Thus, e.g. Also, concentrically variable shore hardnesses can be adjusted by either using masks or by guiding UV laser light accordingly. In use, such UV-based polymer-based sensors must be constructed so that no light is applied to the polymer to maintain the Shore hardness.

The shape of the functional polymer represents another parameter. Roughly, a hemispherical shape has proved to be the starting form. The flattening to the outside and the design of the central location are adjustment parameters.

A layer of resistive polymer is applied to the functional polymer as long as the polymers used are not conductive.

This resistive polymer is available as a color and can be adjusted in its conductivity by the addition of other polymer inks.

These possibilities of adjusting the polymer are of extreme necessity to ensure the mechanical properties of the sensor and thus the electrical properties consistent and in perfect quality.

This results in the meanings or tasks of the individual polymers. The polymer of the design has the task of one to guide the sensor at no load in a defined initial state, on the other hand, a defined back pressure is built up. This back pressure is necessary to suppress mechanical trembling, which in turn would lead to a noise of the measured values. The functional polymer has the task of controlling the contact surface of the resistance-conducting polymer to the interconnects. The functional polymer is characterized in that it has on the one hand a very fast resilience. That the expansion and the relief movement must be able to follow the pulsating pressure wave in their speed. On the other hand, the functional polymer is characterized by the fact that, depending on the mechanical stress, it conforms more or less to the conductor tracks. In this case, the mechanical properties of the functional polymer must also be adjusted so that no lasting impression of the conductor tracks in the polymer can form, not even with frequent loading of the sensor up to the maximum pressure range.

The resistance-conductive polymer establishes contact between the individual interconnects. Its characteristics are that it does not actually have good contact with a track. This is because the microstructure of the surface of the polymer is very uneven. If the polymer comes into contact with a conductor track, initially there are only a few microstructural elevations in contact with the conductor track and a high electrical resistance exists between the polymer and the conductor track. If the contact pressure increases, the microstructure deforms and the actual contact area increases due to the flat pressing of microstructural elevations, the electrical contact improves and there is a low electrical resistance between the conductor track and the polymer. When unloaded, the flattened microstructural elevations relieve themselves and the initial shape is formed back.

A possible construction of a sensor produced in this way is in principle as follows:

The design consists of a polymer with a Shore hardness equal to or higher than the functional polymer. In this case, feet, which may be individual elevations, or concentric structures, adapted in shape and proximity to the functional polymer so that the required counterforce of the sensor is achieved. In the center of the functional polymer, a protruding beyond the shape of the functional polymer survey can be inserted. This may have a different Shore hardness or the same Shore hardness as the functional polymer.

Depending on whether the functional polymer is resistant to resistance, a further resistance-conducting polymer is applied to the functional polymer. The size of the functional polymer depends on the area of the interconnect networks.

Definition of the measured quantities

The definition of the characteristic cardiac output of the cardiovascular system is only possible if initially other parameters such as blood pressure and cardiac output are defined. Therefore, in the following, all parameters that can be measured with an arrangement according to the invention are defined and, lastly, the cardiac output.

Defining the blood pressure

The blood pressure at different points of a human or animal body is also visible to the human eye now and then. In particular, the naked eye can detect in humans the arterial pulse at the A. radialis.

The blood pressure from the heart, thus not only palpable but also visible in the periphery of the human or animal.

This pressure is particularly noticeable on the wrist. Here passes the artery Radialis (See 1 Letter L) under the skin, but close enough to the surface to control the cushioning properties of the fabric (See 1 Subparagraph C). If you look closely, you can usually see a pulsating tissue. The pulsation is produced by the temporal change in pressure at each individual heartbeat.

In the expulsion time of the individual heart rhythms, the pulse wave (See 1 Letter D) generated. This can be registered peripherally as the first reaction of a successful heartbeat.

However, part of the blood volume is not immediately diverted to the periphery. The Windkessel absorbs a portion of the blood volume and releases this portion within a RR interval until complete emptying, measurable as diastole.

This is done to compensate for pressure peaks and to be able to customize the system to the respective load situations.

Arrived in the periphery, the pressure pulse or the current pulse can be registered.

To measure blood pressure non-invasively, the Riva Rocci method has been used for over 100 years.

The method works by squeezing the artery with the aid of an inflatable air bag. Then, controlled and measurable, the uniform pressure load on the artery is released from the outside by opening the airbag.

Now, through the arterial blood pressure, the blood can squeeze through the first opening slits of the passage barrier towards the periphery, and thus re-propagate within the open artery, causing a knocking sound. The Riva Rocci / Korotkow method uses tapping to determine blood pressure.

If a sound of reopened blood flow is detected, systole (See 1 Letter A).

If knocking ceases, the pressure in the arterial vessel is balanced and the pressure of diastole (See 1 Letter B) can be measured.

By closely observing the gauges in the Riva Rocci / Korotkow method, the following can be ascertained. Using an analog pressure gauge to determine the pressure in the air bag, a pulsation of the needle of the gauge and thus of the pressure can be observed. This can be seen when the air bag is loaded with a pressure that is between diastole and systole. There is an air filling in the airbag, in which the fluctuation is maximum.

The values between which the needle varies would correspond to the values for diastole and systole. However, since the air bag dampens the pressure change and the meter does not have the necessary temporal resolution, the values for diastole and systole can not be determined.

The arrangement according to the invention makes use of this event by using sensors with corresponding temporal resolution and with the lowest possible attenuation.

The invention utilizes the incoming pressure / pressure propagation direction to the surface of the human skin (see 1 Letter N), here, for example, at the A. Radialis.

The pulsating pressure from the arterial wall (see 1 Letter E) transplants over the tissue (see 1 Letter C) to the surface of the skin (see 1 Letter O). There, the pulsating pressure / blood pressure, but already damped by the tissue by means of sensory and processing unit registered (see 1 Letter K and H).

The directly measurable pulse pressure has been a proven remedy for medical professionals for centuries, not only in the field of accident care. The type of pulse pressure propagation, 1 Letter N, and the speed of the pulse, 1 Letter M, can give conclusions about the constitution of the measuring person on the basis of the felt pulse statement.

The registerable pressure increase is used directly in the invention as a cause for blood pressure measurement.

The pulsating pressure pulse deforms the artery, 1 Letter E, constant in the beat of the beating heart, 1 Letter G.

On the way to the periphery, the pressure pulse is changed by branching, states of the vessels, as well as the external and internal load. Thus, the blood pressure reading is a constantly adapting value to the particular situation of the body.

Defining the heart pulse

The operation of the heart is controlled by the sinus node, this indicates the tact, with which the heart contracts, causing the ejection of the blood in the first Windkessel and then in the arteries. The sinus node stimulates the muscles of the heart by electrical signals.

A full cycle of expectoration of the blood into the arteries and aspiration process from the veins is a cardiac pulse.

The electrical signals of the sinus node are recorded in the conventional method for measuring heart rate with an electrocardiogram (ECG).

However, this record of these electrical signals, although used worldwide, is inadequate to measure cardiac output, because the electrical signal is only the instruction to perform an action on the heart muscle, the actual action of the heart can not be detected.

In the case of illness, it may happen that the electrical signal of the sinus node can not lead to any expectoration of blood.

An example of this is atrial flutter and atrial fibrillation. In these diseases, the contraction in the atria is triggered by up to 340 (atrial flutter) or up to 600 (atrial fibrillation) contractions per minute by electrical signals. The heart valves open to the heart chambers, however, usually irregularly with 100-160 openings per minute. This condition is called absolute arrhythmia.

Thus, there is only an ejection of blood with a frequency of 100-160 per minute.

Of course, such diseases lead to recognizable patterns in the ECG signal, which can be recognized by those skilled in the art. However, it depends on the experience and training and especially on the knowledge of all possible diseases in the professional.

The arrangement according to the invention determines measured values which map the pulsating pressure wave. The pulsating pressure wave in the arteries comes about only when it comes to a blood discharge from the heart. Thus, an unambiguous measurement of the cardiac pulse is possible via the analysis of the measured values which map the pulsating pressure wave.

Defining the pulse wave variability

The pulse wave variability, also called heart rate variability, indicates the variability of the cardiac pulse. High variability is a sign of a healthy heart.

The heart pulse adapts autonomously to the requirements of the organism and is therefore inferior to a constant change. If the person to be examined is, for example, under increased stress, the result may be an even cardiac output.

By virtue of the recording of a measured value curve which maps the pulsating pressure wave, the arrangement according to the invention permits the time intervals between each individual heart pulse to be determined. These intervals are called RR intervals.

For example, the pulse wave variability can be expressed as the standard deviation to the mean of the RR intervals.

Defining the pulse wave transit time and pulse wave velocity

Pulse wave transit time and pulse wave velocity are two closely related characteristics of the cardiovascular system.

The pulse wave transit time indicates the time in which the pulse wave has traveled a certain distance and the pulse wave velocity combines the pulse wave transit time and the distance traveled. Therefore, from the knowledge of the distance traveled, the two parameters can be converted into each other.

In addition, the pulse wave velocity must not be confused with the speed of the blood in the arteries, this is much slower.

Starting from a heart pulse, a pressure pulse sets in the arteries in motion, this deforms the arterial walls. In turn, this means that the pressure pulse can only move as fast as the arterial walls can deform. This deformability is the elasticity of the arteries.

Thus, the elasticity of the arteries can be determined by measuring the pulse wave velocity. The value of elasticity is regulated by the cardiovascular system.

In case of illness, the elasticity may e.g. be excessively reduced by arteriosclerosis. Therefore, the elasticity is a characteristic, e.g. warn of impending heart attacks.

In addition, studies have shown that, at least over short periods of time, the pulse wave velocity can also be used to monitor blood pressure.

For the measurement by the inventive arrangement, there are two approaches.

On the one hand, the pulsating pressure wave can be measured with several sensors at different points of the body. Thus, the pulse wave transit time can be determined from the offset of the measured curves relative to one another, whereby, knowing the distance of the sensors from one another, the pulse wave velocity is also known.

Since the inventive arrangement has a high data acquisition rate, the sensors can also be close to each other. This allows the measurement of the pulse wave velocity locally on the body.

On the other hand, the pulsating pressure wave of the heart pulse is also reflected. Due to the high data acquisition rate of the inventive arrangement, the reflection wave is recognizable in the measurement curves. The pulse wave transit time can be calculated from the distance between the initial wave and the reflection wave.

Defining cardiac output

The cardiac output indicates how many liters of blood the heart expels in one minute and is available for the care of the organism. Thus, this characteristic is the quantity for assessing the performance of the cardiovascular system.

A normal reduced value is an indication of heart disease, e.g. heart valve disease or an indication of hypothyroidism.

A normal elevated level may be due to a variety of disorders, such as fever, anemia, or circulatory disorders of organs.

Cardiac output is also an indicator of oxygen supply to the body. For the athlete, therefore, a high cardiac output (as long as it is not disease-related) is desirable and can serve as a measure of specific, performance-oriented training measures.

Another area of application, which results from the connection with the oxygen supply, is patent control in operations. Cardiac output is already measured continuously in many surgeries, but this is done invasively using a variety of methods. One method that is often used involves injecting a cold fluid with a catheter into a chamber of the heart. By means of temperature sensors in the arteries following the heart, the heating can be determined; this heating is directly related to the cardiac output.

In summary, the methods for cardiac output determination are either very inaccurate or require an intervention in the body that is only justifiable in exceptional situations.

An inventive arrangement is intended to provide an alternative to the invasive methods, which on the one hand requires no intervention in the body and thus no dangerous operations and, on the other hand, enables the most accurate measurement of cardiac output. Therefore, the location between the medically very precise and necessary examination situations in complicated and long operations and the very inaccurate previous non-invasive methods. Therefore, an invasive method can be dispensed with in operations that do not require the highest accuracy, and an inventive arrangement can be used instead. Since the attachment of an inventive arrangement is quick and straightforward, it is also possible to monitor during operations in which no cardiac output monitoring has hitherto been used.

In addition, especially in the medical field, new possibilities arise, so a continuous long-term monitoring can be made possible and in case of deterioration an alarm can be issued.

The determination of the value for the current cardiac output can be from cardiac pulse to cardiac pulse. The parameters of the heart rate pulse or the RR interval, the pulsed pressure wave measurement curve, the arterial elasticity and the diameter of the aortic arch in diastolic blood pressure are used.

Only the diameter or radius of the aortic arch in diastolic blood pressure can not be determined by an inventive arrangement and must be compatible with external devices e.g. Ultrasound to be determined. However, in a continuous long-term monitoring not so much the absolute value plays a role, but the changes. An inventive arrangement can measure the cardiac output relative to the diameter of the aortic arch in diastolic blood pressure, and if desired, this relative value can be converted to an absolute value by an external measurement of the diameter of the aortic arch in diastolic blood pressure.

The pulse wave passes from the heart into the arteries, while the amplitude decreases and the individual pulses are longer in time. However, the output pressure wave must traverse all arteries and the total pressure at a certain distance from the heart must correspond to the ejection pressure, which is related to cardiac output and elasticity.

Thus, the ejection volume of a cardiac pulse can be estimated as follows: The currently present pulse pressure P (t) (pulse pressure is the pressure difference between the diastolic blood pressure value and the current measurement value) in an artery deforms this, the radius R is given by the elasticity E: $$R\left(t\right)={\text{<figure-callout id="0" label="R" filenames="DE102017002334A1\_0019.png" state="{{state}}">R</figure-callout>}}_0+\text{e}*P\left(t\right)$$

Here, R _{0 is} the (unknown and externally measured) radius of the artery.

The current radius of the artery changes during a cardiac pule with the time pressure.

To calculate a volume, the length and deformation of the artery in a cardiac pulse must be determined. For this, the temporal length of a cardiac pulse, the RR interval T, and the pulse wave velocity v are linked: $$\text{L}=\mathrm{\nu }*T$$

Since the current time t (start time is the beginning of the heart pulse with t = 0) in the pulse with the current position in the artery (t) is comparable comparable to the pulse wave speed: $$l\left(t\right)=\mathrm{\nu }*t$$

Can the current radius also be represented as a function of l.

R '(l) = R (l / v)

The volume results from the integration of all measured values in a heart pulse under the known formula for determining the cross-sectional area from the radius (area = πR ² ): $$\begin{array}{c}\text{V}={\displaystyle \int \pi {\left(\text{R}\text{'}\left(l\right)\right)}^2\text{dl}=\mathrm{\pi }{\displaystyle \int {\left(R\left(l\text{/}\nu \right)\right)}^2\text{dl}\mathrm{=}{\displaystyle \int {\left(R\left(t\right)\right)}^2\mathrm{\nu }\text{dt}}}}\\ \pi {\displaystyle \int {\left({\text{<figure-callout id="0" label="R" filenames="DE102017002334A1\_0019.png" state="{{state}}">R</figure-callout>}}_0+\text{e}*P\left(t\right)\right)}^2\mathrm{\nu }\text{dt}}\end{array}$$

For a relative measurement R ₀ is set to zero, if an external measurement has taken place R ₀ can be transmitted as a parameter to the inventive arrangement.

Process of measurement

A pressure sensor, as already described above, is applied to the skin, 1 Letter K and O, placed.

In order to achieve a uniformly applied pressure, a bracelet, 1 Letter I to be used to the wrist as an aid and as a commercial product available.

Thus, a uniform pressure, 1 Letter J on which A. Radialis are exercised.

The outgoing pressure transmitted from the A. radialis to the surface of the skin can already be registered with a simple measurement setup of a pressure sensor between the bracelet and the surface of the skin.

The dynamic pressure pulse of the actual ejection of the heart can be made so visible to everyone by means of the evaluation and imaging unit. Thus, the arrangement according to the invention has an invaluable value for patients who are invasively connected to a monitor, for example, in the intensive care unit, since the measurement does not have to be performed invasively, as is usual today.

The measurement of blood pressure can be greatly influenced by the surrounding tissue. Therefore, precautions must be taken in special cases.

In people with high fat content or moderate expression, it may come at the preferred location for measuring blood pressure and heart pulse on the wrist to increased attenuation of the measurement. An advantageous measuring point is at the upper back of the foot, as there are usually stored little fat and as back pressure sufficient bone and cartilage are in this area. Measuring points such as the artery Dorsalis pedis, anterior tibial, Posterior tibiels, as well as First dorsal metarsal, Deep plantar, Arcuate are suitable for measurement on the back of the foot. In the area above the ankle, the total amount of inflowing bloodstream changes the diameter of the lower limb. With a measurement of the variable diameter or the variable pressure on the applied measuring surface, the blood pressure and heart pulse can also be detected here.

A limited usability of the invention also exists in diseased people, for example. By strong water deposits in the legs and especially in the feet.

However, to measure the blood pressure clearly, it requires a defined back pressure from the outside (see 1 Letter J).

Defined in the case of the invention means any, but known, external pressure transferred to the measured artery, for example by means of a bracelet or airbag as in the Riva Rocci method.

The required back pressure can, for example, by means of a finger (see 1 Letter J) of the other free hand.

For this purpose, preferably for the invention, a specially prepared and clearly defined for the user surface on the bracelet can be created. This surface is located above the sensor and thus, for example, on the bracelet. Directly below the sensors is the A. Radialis.

For a blood pressure measurement, the user must, for example, lead a finger on the defined surface of the bracelet. A gently and steadily increasing pressure increase on the wristband, caused by the building pressure of the finger on the marked area, is registered and stored by the system with at least 1000 measurements per second.

The user feels a more perceptible pulsation when gently pressing on the A. radialis. This increase in the perceptible pulse is not due to an increase in blood pressure but due to the compaction and distribution of the surrounding tissue between the skin surface and the existing tissue above the A. radialis.

The pressure sensor measures the increase of the pulsating wave. Like a squeezed out sponge, the tissue pushed together and pushed away gives the pulsating wave, starting from the arterial wall, almost 1 to 1 to the pressure sensor. The damping of the tissue, 1 Letter C, is reduced by the back pressure of finger or an actuator, 1 Letter J, from the outside and thus above the skin, 1 Letter O.

To measure the systole of blood pressure, the back pressure on the artery or pulse wave (See 1 Letter D) beyond the attenuation.

The systole becomes measurable at the moment the backpressure continues to increase, but the pulse wave can not produce a maximum increase beyond the maximum measured pressure.

The invention can easily be tested on humans themselves. Before squeezing the A. Radialis completely with the increasing pressure on the radialis, there is a pressure range in that, despite an increase in the back pressure, the pulse pressure does not noticeably increase any further.

This point can be measured by known devices and represents the systole of the blood pressure.

Diastole is determined from the minimas of the pulsating pressure wave. As the back pressure on the artery increases, the distance between the minimas and the maxima of the pulsating pressure wave initially increases, with the maximum pressure also increasing. From a certain backpressure the maximum measured pressure does not increase any further. This is just the back pressure that corresponds to the diastolic blood pressure.

As the backpressure increases further, the minimas continue to rise, the maximas of the pulsating pressure wave remain constant.

A single measurement can therefore be made by slowly increasing the back pressure on the artery until no increase in the maximum in the pulsating pressure wave can be detected.

The continuous measurement is done the same way first, but at the point where no increase of the Maximas can be seen remains. If the systolic blood pressure changes, this can be detected by a change in the maximum of the pulsating pressure wave. Now, the back pressure must be adjusted again to determine the new value for the blood pressure. If only the diastolic blood pressure increases, the distance between the minimas and the maxima in the pulsating pressure wave changes, and it is necessary to readjust the backpressure. Only the unlikely event of a falling diastolic blood pressure, with constant systolic blood pressure, can be recognized only by periodically re-adjusting the back pressure.

The measurement of the cardiac output requires the simultaneous measurement of the pulsating pressure wave at different locations. For this purpose, pressure sensors are attached to at least two suitable measuring points and loaded by an actuator or manually with the optimum measuring pressure of the continuous measurement. The distance of the sensors, with separated sensors, must now be measured and transmitted to the inventive arrangement. In a sensor array, these distances of the inventive arrangement are known. The calculation of cardiac output is now automatic.

Basic structure of a heart time volume measuring system according to the invention

In order to measure the cardiac output without doubt the pulse pressure, for example, starting from the A. Radialis, coincident with the back pressure starting from the user's finger, is advantageously to be measured with at least 1000 measurements per second.

At least 1000 measurements per second are necessary for a medical examination and thus advantageous.

For a blood pressure measurement, only one pressure sensor is necessary, but the use of multiple sensors is advantageous. The cardiac output is measured with at least two sensors at different measuring points.

The multiple measurement of the current blood pressure at each measuring point allows to represent the course of the blood pressure between diastole and systole in each individual pulse. This is particularly advantageous for assessing the cardiovascular system. For example. the reflection wave can be detected. If this is, for example, increased in relation to the initials pressure wave, this indicates a vascular stiffness. The examination of the reflection wave represents a possibility to determine the elasticity of the arteries.

However, the measurement of blood pressure can also be measured at less than 1000 measurements per second.

The invention also provides the solution to generate the back pressure by means of actuator. The advantage is the even increase of the acting back pressure on the artery.

The advantage of using an actuator is the timely cancellation of the measurement, or the back pressure on the artery, before the back pressure squeezes the artery.

Also, therefore, the blood pressure measurement can be done automatically, for example, during the night and gently.

The actuator can, for example, electrically, pneumatically, hydraulically or manually solve by muscle contractions the task of generating the back pressure. The combination of all solutions with each other and against each other allows the application.

The actuator for generating the backpressure may be, for example, a conventional and SMD-type electric vibration motor. But also any other actuators can satisfy the buildup of backpressure. This is known to the person skilled in the art.

However, the actuator also has the disadvantage that electrical energy is consumed. This must be calculated in the respective application.

Currently, manual and actuator-controlled locking systems, for example in the shoe or in cuffs made by Boa Technology. Market leaders such as Nike (HyperAdapt 1.0), Puma (Ignite Disc), Reebok with the "The Pump technology", or the French company Digitsole (Smartshoe 002) also installed actuator-controlled locking systems in a product for the first time in 2016. Thus, "shoe" already has simple automated and integrable prerequisites for continuous pulse and blood pressure measurement.

But it is also possible to generate the required back pressure with the forearm muscles by muscle contractions, eg. By opening and closing the hand. Thus, the measurement can be made by one person without the help of a finger of the other hand, or a third party, or even another actor.

A further advantageous invention provides the use of a convex structure, see 3 Letter Q, as a carrier form of the system. The arterial system is usually protected and secured inside the body. In the extremities often only the veins are clearly visible. The arterial circulation is deeper in the tissue. Only in a few places of the body can arteries be felt in a striking way through the pulsating wave. In order to be able to measure also non-visible arteries, the convex structure, 3 Letter Q, an innovative novelty. The convex structure nestles almost exactly in the concave forms of the body, such as the A. Radialis.

Placing the convex structure on the concave shape that forms above the radial artery and towards the surface of the skin allows an optimal pulse wave to be registered and stored. The same applies, for example, also for the foot.

In order to produce a uniform surface pressure on the artery on the foot or the forearm / wrist, it is advantageous to incorporate foam or foam-like material between the flexible sensor unit and the pressing body, for example a convex structure. The foam, similar to the tissue above the finger bone, serves as a resonator.

The functional Shore hardness of the pressing body can be adapted to the tissue of a fingertip.

In order to be able to correctly place the convex structure, for example in the size of half a pea, the task can be solved with the aid of sliding glides on a bracelet, for example a watch strap, and also with the aid of straps. An even more accurate placement can be achieved by using multiple sensors, see below.

A conventional watch strap has at least one tab, 2 Letter P, for the protruding perforated belt for optimum adjustment of the clock pressure on the wrist. Without a tab, the protruding perforated tape and without insertion into the tab, (for example, leather bracelet) would turn away from the shape of the wrist and stick out. The attachment of the measuring unit is carried out as follows:

The measuring unit comes with the opening, 3 Letter I, like a flap / tabs, see 2 Letter P, pushed on the bracelet.

The attachment of the measuring unit, in a size of, for example. And about 10 × 20 × 8 mm, is guaranteed.

Above the bracelet is, for example, see 3 Letter H, the arithmetic and radio unit and the power supply.

The convex structure with the associated pressure sensor is located below the bracelet. Please refer 3 Letter Q.

The measuring unit plus the convex structure can measure the blood pressure in this construction with each already used bracelet.

The inventive novelty is thus also in the variable usability of already existing bracelets for watches, jewelry or smart devices. The tab opening of the measuring unit can be made so wide that not only the convex structure on the bracelet can be moved around the wrist, but also with the tab, or within the tab, the convex structure including measuring unit, to the hand, or moved away from the hand.

Thus, the invention, for example, to the surface of the skin, can be easily placed and serve as a mobile solution to measure the various characteristics of the cardiovascular system.

To optimize a better placement of the invention, for example, the measured value can be transferred to a mobile smart device.

Through several tiled pressure sensors, see 1 Letter K, as well 3 Letter K, within the convex image, is the optimum location for registering the physical pulse wave determine. A display of the action statement, for example on a smart device, solves the task for the correct placement by means of arrow directions displayed on a screen.

However, it is also possible with a single pressure sensor and without the use of a convex structure to measure the various characteristics of the cardiovascular system.

Advantageous is the use of a convex structure on which several sensors are distributed. Ideally, these sensors cover the entire surface. For the measurement of the various characteristics of the cardiovascular system, there are now several sensors to choose from, which in turn have several (for example two) measuring ranges. In order to determine which sensor lies optimally above the artery, the signal of all sensors is examined. This signal changes in the course of a pulse. The optimal sensor is characterized by the highest amplitude. The best measuring range is determined by the maximum value. The smaller the measuring range, the more accurate the result.

Regardless of which variant is used for which application, the data from the pressure sensor (s) are transferred to an evaluation unit and to a picture or sound output by means of recording, computing power and transmission unit.

Preferred here is the mobile solution such as a smart device, such as a clock or smartphone.

In order to transfer the required electronic components, the skilled person these are known in detail, SMD modules are used to keep the structure small and low in weight. An adapted power supply unit for the respective application solves the task of power supply See also 3 ,

The system can be equipped with a rechargeable battery or a battery, it would also be advantageous to ensure the provision of energy via a smart device, for example a watch or a smartphone, or even within the bracelet of fitness trackers.

Thus, furthermore, the measuring sensor system can also be formed separately in the convex structure and access external units (rake, radio, etc.), for example a smart device.

This division would not only have sizes and energy advantages, since the smart devices already have a complete infrastructure for operation and evaluation.

Tiling as already described offers advantages in detecting the optimum position of the measuring unit and also for measured values in peripheral areas which can give more reliable information on propagation times and speeds of the pulse wave. For this purpose, all around the pressure sensors are arranged on the convex structure. With this arrangement, the pressure waveform of the pulse wave can be measured without, as well as with a convex structure 3 Letter K shown as a section.

At the same time, the "shutters" of data determinations, by means of cross-over of electrical traces, see this 4 , for faster readout of the pressure sensors.

The tiling of sensors, see 4 , And the crossover circuits of electrical traces, thus represent another inventive activity for measuring the blood pressure or cardiac output.

As with pulse measurement, the general public has been little known that the pulse constantly adapts to the circumstances. The adjustments lead to significant changes from beat to beat in healthy creatures / humans. The respiratory sinus arrhythmia is probably the strongest influencing factor under "normal" conditions. The introduction of visual visualization of the heart pulse with smartphone devices has made this circumstance recognizable.

The introduction of non-invasive continuous blood pressure measurement with a very simple sensor unit is inferior to current understanding of cardiac output.

In addition, the respective blood pressure, whether measured on the upper arm, forearm or foot, constantly changes during movement of a person, for example as a result of running, the position to the height and thus to the hydrostatic point of indeterminacy (HIP).

The blood pressure is thus dependent on the location of the measuring point to the HIP. As described further in the patent, the determination of the central continuous blood pressure, the temporal and spatial resolution to HIP the measuring point in the periphery / extremities is necessary.

In the horizontal storage of the living being, for example. Man, the location of the measuring point is negligible, since all measurable vessels are located in almost the same height to HIP.

The invention can advantageously generate and control the back pressure for medical applications with the known airbag of the "Riva Rocci method" in order to measure the blood pressure at the wrist, ankle or foot.

Contrary to the Riva Rocci method, however, systole and diastole can be measured continuously and in the same RR interval.

Especially advantageous is the general application of the invention for blood pressure measurements without affecting the mobility and handling of the hands. The measurements on the foot produce only small changes in the movement to the HIP. The general pressure build-up by attaching the shoes with shoelaces, or as new with technically developed automatic locking systems, are integrated almost unnoticed in commonplace actions.

Continuous measurement in the movement

In order to determine the time course of the blood pressure within a pulse and over several pulses also from the physical movement, the height to the HIP (hydrostatic indifferent point) must be known. The measured blood pressure eg in the arm changes depending on the height above the HIP. The change of the blood pressure in the arm due to the height change Δh results as follows: $$\mathrm{\Delta }\text{P}\mathrm{=\; \alpha \Delta }\text{H}$$

Here, α is an empirical measurement with the value of approximately α = 1 mmHg / cm for the systolic blood pressure and approximately α = 0.5 mmHg / cm for the diastolic blood pressure.

If the current height of the arm is known and the blood pressure Pm in the arm can be measured, the central blood pressure Pz in the HIP can be calculated: $$\text{pz}=\text{pm}\mathrm{-\Delta }\text{P}$$

The height of the arm can be determined with different technologies. Possible known methods are the determination of the distance to a reference surface. This can be done, for example, with an ultrasonic distance sensor or with a laser range sensor. These sensors emit a signal (sound or laser pulse) which is sent to a fixed, i. Reflected outside the body, reference surface is reflected. The length is determined from the transit time of the signal to the reference surface and back. This results in two technical challenges. For one, the sensor must be directed to the reference surface. This is difficult to realize, especially in the case of arm movement, which is normally not linear. On the other hand, a suitable reference surface must be present at a known position. This could be the ground, but this is not always such that the sound impulse (e.g., forest floor) or the laser pulse (wet floor whereby the reflection is not back to the sensor) can be reflected.

For these reasons, a distance measurement without a reference surface using an acceleration sensor is advantageous.

The current height of the arm can be determined by using an acceleration sensor.

From the measured values of the acceleration sensor, the Velocity-Verlet algorithm allows the movement of the arm to be understood and the current location of the arm to be determined.

However, since minute inaccuracies, such as occur in today's acceleration sensors, lead to large deviations of the location of the arm when measuring the acceleration, the sequence of movements in each step must be accurately assessed to determine the correct position of the arm. The procedure for this is to set the measured acceleration data in comparison to the expected acceleration data of the arm movement. For this purpose, known motion patterns are compared with the current acceleration data. If a match is detected, the movement to the current position can be determined.

Example of electronic conversion using SRS sensors

Switchable resistive sensors (SRS) have at least two measuring ranges. The sensor itself constitutes an electrical resistance which changes its resistance value by force or pressurization. The SRS has such resistors for every measuring range.

The current electrical resistance of a measuring range of the sensor can be done in the simplest case on the use of the sensor in a voltage divider. The voltage that drops across the sensor is the output measurement signal.

However, the measurement signal determined in this way is not accurate enough as far as the printing resolution is concerned.

However, this measurement signal reflects the basic pressure again.

The sensor can also be read in a second way. For this purpose, the voltage which drops across the sensor is AC-coupled with a differential amplifier. Advantageously, the gain is adjustable.

This signal changes with the smallest changes in the voltage drop across the sensor and thus with the smallest changes in the pressurization. However, the signal due to the AC coupling is independent of the actual pressurization.

The arrangement according to the invention therefore receives from a pressure sensor two principal signals, see also 5 :

An unreinforced signal reflecting the basic pressure (example in 5 Letter R) and an amplified signal corresponding to the mathematical time derivative of the pressure signal (example in FIG 5 To see letter S).

The technical measures described in this example for receiving the measurement signals can also be realized differently. Other examples for receiving the unamplified signal are e.g. the use of a Wheatstone bridge, the constant current method for resistance determination or the installation of the sensor in a resonant circuit. The skilled person many ways are known to capture these signals.

The voltages generated by these electronic structures are quantified with a microcontroller using an analog-to-digital converter. Depending on the computing power of the microcontroller used, the quantified signals can either be evaluated directly or transmitted to an evaluation unit. Advantageously, the transmission of output data or calculated results to an evaluation unit or display unit by radio, e.g. with the Bluetooth standard.

Use of the measuring ranges of an SRS sensor

Each measuring range of an SRS sensor covers a fixed force range. Advantageously, the force ranges overlap. When switching, a fixed force value should not be selected. Instead, two force values should be chosen. If the force is increased and the force value is exceeded to switch up in the current range is switched to the next higher range. In the higher measuring range, the force value for downshifting is now smaller than the force value in the smaller measuring range for upshifting. This prevents unnecessary switching back and forth due to measurement noise when the applied force is in the range of the switching limits.

Preparation of the measuring signal

The measuring electronics supplies two signals which correspond to the basic pressure (S _G (t)) or the mathematical time derivative of the pressure (S _D '(t)).

The basic signals are first converted into the SI units N or N / s by a sensor-type-dependent calibration.

The times of changes of the (electronically detected) signals are different. S _G (t) changes only gradually with a change in imprint or a general change in blood pressure. S _D '(t), on the other hand, changes continuously with the pulsating pressure wave, thus reflecting the activity of the heart. However, due to the electronics, the signal "forgets" changes in pressure over longer periods of time and thus always fluctuates around a zero value.

Mathematically, the actual force on the sensor F (t) results at the time of the following approximation: $$F\left(t\right)={\text{S}}_G\left(\text{t}\right)+{\displaystyle \int S_D\text{'}\left(t\right)\text{dt}}$$

Here, t _{0 is} a time before the actual measurement in which S _D '(t) = 0 for all times t <t ₀ .

However, under real conditions, this mathematical approximation is not directly usable without further improvements due to various challenges. These challenges include, but are not limited to, measurement noise or sudden changes in the imprint, especially during manual measurement. Therefore, possible strategies to improve the generation of measured values are shown below.

The signal S _D '(t) should only change for changes in the pressure on small time scales, in order to ensure this, a running average S _D ' (t) is first determined via the signal S _D '(t).

Subsequently, the integral of the signal S _D '(t) is approximated as a sum: $${\displaystyle \int S_D\text{'}\left(t\right)\text{dt}}\approx {\displaystyle \Sigma \left(S_D\text{'}\left(n\right)-S_D\text{'}\left(n\right)\right)*\mathrm{\Delta }\text{t}\left(n\right)}$$

Here n is the number of measured values since the beginning of the measurement and Δt (n) is the time interval between the measured values S _D '(n-1 and SD'n). The time t is given by t = Δtn.

Since errors occur with every numerical integration and since the measured values can also be noisy, the execution of the integral must be further optimized. Therefore, the sum is replaced by a recursive sum and the result of the integral I (t) results as: $$I\left(t\right)\approx {\displaystyle \Sigma \left(S_D\text{'}\left(n\right)-S_D\text{'}\left(n\right)\right)*\mathrm{\Delta }\text{t}\left(n\right)\approx \left\{\begin{array}{c}{I}_0=0\\ I_n=\mathrm{\alpha }{\text{I}}_{n-1}+\left(S_D\text{'}\left(n\right)-S_D\text{'}\left(n\right)\right)*\mathrm{\Delta }\text{t}\left(n\right)\end{array}\right\}}$$

Here, for the attenuation factor 0 <α <1. This factor weakens the influence of older measurements and prefers new values. This prevents calculation errors and measured value noise from accumulating. The factor must be empirically adapted to the type of sensor used.

This results in the measured value of the pulsating pressure wave P (t): $$P\left(t\right)=\mathrm{\beta }\left(S_G\left(t\right)+\text{I}\left(t\right)\right)$$

Here, 1 / β is the active area of the sensor.

Logic for evaluation of the pulsating pressure wave Determination of the best positioned sensor in a sensor array

When an array of multiple sensors is used to find the optimal position over an artery, all sensors are initially read over a period of several heart pulses. Depending on the capabilities of the measuring electronics, this can be done simultaneously or in succession. Preferable is a simultaneous reading.

The best positioned sensor is characterized by its position directly above the artery. Therefore, at this point, the amplitude of the pulsating pressure wave is maximum. This sensor is used for further measurement.

In a continuous measurement, the detection of the best positioned sensor is repeated at periodic intervals. The use of an acceleration sensor is advantageous. With this sensor, the physical movement of the person or animal to be examined can be detected. If the movement is too strong, a new detection can be triggered.

Determination of the heart pulse

The heart pulse is determined from the measured values of the pulsating pressure wave. For this, the measured value curve is examined for prominent points. This can be the Maximas in the curve. The time interval of two consecutive Maximas is the RR interval of the heart pulse in the unit number / minute is calculated according to the following formula: 60s / RR in seconds.

Determination of diastolic and systolic blood pressure values

As already described, the systolic value of the blood pressure results when pressure is applied to the sensor when no increase in the maximum of the pulsating pressure wave can be detected when the pressure increases.

At the point of lowest pressurization, at which no further increase in the Maximas can be seen, the value for the diastolic value of the blood pressure can be determined. This pressurization is also characterized by a maximum amplitude of the pulsating pressure wave.

Therefore, the measured values of the pulsating pressure wave are continuously examined for minimas and maximas. The person skilled in various mathematical approaches are known.

For the systolic value of the blood pressure, the value of the highest maximas and for the diastolic value of the blood pressure, the value of the minimum, at which the greatest distance to the adjacent maximum exists.

In a continuous measurement, an actuator increases the pressure on the sensor to the optimum measuring situation. Smaller changes in blood pressure can be measured continuously. If the blood pressure changes more clearly, as already described, this can be recognized by the change in the systolic blood pressure reading. If there is a change in the systolic over a limit value, the actuator must be readjusted to pressurize the sensor.

Determination of the pulse wave velocity

A pulse wave velocity results from the measurement of the pulsating pressure wave at different points of the body. However, the points must be on a line between the heart and the point farthest from the heart.

This can be done by two principal approaches. On the one hand, a plurality of at least two arrangements according to the invention can be distributed on the body or other devices for cardiac pulse determination can be used in addition to the arrangement according to the invention. The prerequisite for the use of external devices is an open interface for the collected data and a real-time determination of the data as a heart rate-dependent measured value curve.

Advantageously, another arrangement according to the invention with a plurality of sensors is used.

The measured value curves of the individual devices or of the individual sensors are examined for significant points. In the case of the arrangement according to the invention, these can be the maximas of the measured values of the pulsating pressure wave.

The distinctive positions of the various devices or sensors have a temporal offset to each other depending on the position on the body. This time offset divided by the distance of the measuring positions to each other gives the pulse wave velocity.

The use of a single inventive arrangement with multiple sensors is advantageous.

The sensors of the arrangement according to the invention can either be separated and thus be attachable at arbitrary locations of the body or can be designed as a sensor array, as already described for the determination of the optimal position over an artery.

The use of a single arrangement according to the invention is advantageous in that the data acquisition can take place simultaneously without transmission times of the data and thus a more accurate measurement is possible.

The use of a sensor array has the advantage of easy handling and simultaneous determination of blood pressure and pulse wave velocity.

To illustrate the use of a sensor array is in 6 Letter K shows a possible arrangement of a sensor array. Below is the course of an artery displayed ( 6 Letter L). Are two sensors selected above the artery ( 6 Letter V), the pulse wave velocity can be determined from the measured value curves of the two sensors ( 6 Letter W).

Determination of the respiratory rate

The respiratory rate can be measured and determined using different methods. On the one hand, motion and acceleration sensors can measure the lifting and lowering of the upper body and determine the respiratory rate. Respiratory sinus arrhythmia (RSA) is a clear sign of respiratory rate determination. The change in cardiac output is directly related to the pulmonary circulation / small circulation. All the blood needs to go through the lungs to absorb oxygen.

Length measurement of a movement by means of an acceleration sensor

All previous methods for length determination or distance measurement are based on objects that are outside the object to be measured. Here is a known example called the automobile. This determines its driven distance (odometer) about the movement of the tire on the road. Here an external object (road) is required to measure the distance of the object to be measured (car). Another possibility of distance measurement in the automobile is track recording by satellite-based position determination. Here, the outside necessary objects are the satellites.

In order to equip a moving object with a logic for measuring its movement, there are already known concepts of sensor technology. Here is, for example, the distance measurement by means of ultrasound or laser called. This sensor sends out a signal (sound or laser pulse), which is reflected at a fixed reference surface. The length is determined from the transit time of the signal to the reference surface and back. This shows that these concepts also require an external object (reference surface) for the measurement.

These concepts also create two technical challenges. For one, the sensor must be directed to the reference surface. This is particularly difficult to achieve in non-uniform motion (e.g., arm movement while walking). On the other hand, a suitable reference surface must be present at a known position.

In the case of human movement while walking, this could be the ground, but this is not always such that the sound impulse (eg forest floor) or the laser impulse (wet floor, whereby the reflection is not directed back to the sensor) can be reflected. In addition, the soil allows only a measurement of the height, but not the measurement of the run track.

The use of an acceleration sensor for the determination of distance or position positions is therefore advantageous, since the measurement is based only on ubiquitous physical laws of mass inertia.

The arrangement according to the invention uses the following logics in order to generate three-dimensional distance data from the raw data of an acceleration sensor. These logics are explained below.

Data of the sensor:

genannt, vor. Diese Daten werden in einem Zeitintervall t_S periodisch generiert. Bei aktuellen Beschleunigungssensoren ist t_S in der Größenordnung von 1ms.The data of an acceleration sensor lie as a three-dimensional vector, in the following $\overrightarrow{A_S}$

called before. These data are generated periodically in a time interval t _S. For current acceleration sensors, t _{S is} on the order of 1 ms.

im Ortssystem des Sensors vorliegen, die zu ermittelnden Größen jedoch im Ortssystem, in dem sich auch das Objekt befindet, zu ermitteln sind.It should be noted that the data $\overrightarrow{A_S}$

present in the local system of the sensor, the quantities to be determined, however, are to be determined in the location system in which the object is located.

auch in Ruhe gemessen wird. Der gemessene Wert des Beschleunigungssensors ergibt sich daher wie folgt: $$\overrightarrow{A_S}={\text{M}}_{E\to S}\overrightarrow{A}{\text{'}}_G+\overrightarrow{A_B}$$

In addition, gravity has an effect on the sensor, allowing acceleration $\overrightarrow{A}{\text{'}}_G$

also measured at rest. The measured value of the acceleration sensor therefore results as follows: $$\overrightarrow{A_S}={\text{M}}_{e\to S}\overrightarrow{A}{\text{'}}_G+\overrightarrow{A_B}$$

ist die Beschleunigung, welche aufgrund der Bewegung vorliegt.Here M _{E → S is} the matrix which describes the rotation of the sensor to the ground and $\overrightarrow{A_B}$

is the acceleration that is due to the movement.

unabhängig von $\overrightarrow{A}{\text{'}}_G$

zu ermitteln. Jedoch ist die Matrix M_E→S im allgemeinen unbekannt.The goal is so $\overrightarrow{A_B}$

independent of $\overrightarrow{A}{\text{'}}_G$

to investigate. However, the matrix M _{E → S} is generally unknown.

Determination of M _{E → S} :

In principle there are two methods to determine M _{E → S.} On the one hand, a gyroscope can be used. On the other hand, the measured acceleration data can be set in comparison to the expected acceleration data of the movement. For this purpose, known motion patterns are compared with the current acceleration data.

The use of a gyroscope allows a simple calculation of M _{E → S.} Today's integrated circuit-based gyroscopes reflect the rotation relative to the home position. It is known to the person skilled in the art how a rotation can be converted into the form of a rotation matrix.

However, today's integrated circuit gyroscopes have the disadvantage of consuming a lot of power and failing to achieve the required accuracy.

The determination of M _{E → S} based on known motion patterns assumes that a movement repeats itself. The movement does not have to be exactly the same, but the basic sequence of movements must be known. An example of this is the movement of the foot while walking. The process is as follows, initially the foot is on the ground, then it is lifted in a rolling motion from the ground to then be moved in a forward movement one step length forward. At the same time, the foot rotates, so that it can be unrolled when settling again. The individual phases are always present when walking, however, the time lengths of the individual phases can vary and the length, height and rotation movements that occur can vary.

If these individual phases of the movement are known, the current movement phase can be determined on the basis of significant or typical changes in the time profile of the acceleration data become. For the example of walking, this means that when the foot is on the ground, there is no additional acceleration in addition to the gravitational acceleration and the acceleration data remains the same from one step to the next. On the basis of such kind of logical connections which occur during the movement, the movement phase can be recognized.

Advantageously, the combination with other sensors can be used. Here, for example, they called the sensors for measuring the force distribution at the sole of the company NWTN. This detects the loads on the foot and the distribution of forces. This results in each movement phase typical distributions of forces. When the foot is at rest, the load is distributed on three points (front foot and heel) in the foot.

Since it is also known how the gravitation is directed in each movement phase in the local system of the sensor results from the knowledge of the movement phase.

Calculation of location and speed:

• (im Ortssystem des Sensors)

bzw.:

• (im Ortssystem der Erde)

When the rotation of the sensor to the earth is known by the rotation matrix, the acceleration resulting from the motion is as follows:

• (in the location system of the sensor)

respectively.:

• (in the local system of the earth)

Here, the inverse rotation matrix is for.

The speed and the location result from the temporal integration of the values with the Velocity Verlet algorithm. The use of the following variant is advantageous:

The current location is derived from the Ortwelcher in the previous time step, the speed that resulted in the previous time step and the current acceleration. The current speed results from the acceleration that resulted in the previous time step and.

The initial values are set to zero.

Optimization of results:

Due to inaccuracies of today's acceleration sensors, the calculated location data can deviate far from the actual movement. The deviation of the movement can be reduced if the principal movement is known. If a known movement form is detected in the movement, the data is set to the expected values, so that in the next time step exactly starting conditions are present again. For the example of walking, this means that when the foot is on the ground, the foot has zero speed and acceleration, and the location remains.

Correlation, influence and presentation of parameters of the heart function against physical actions of a living organism

Every day mobile and smart systems are measuring millions of people. Pulse measurements and movement patterns are the leaders in the measured data. The measurements of cardiac output, blood pressure, cardiac output, pulse wave transit time, pulse wave variability, respiratory rate described in the specification may enable an assessment of the performance and health of a human or animal.

Performance is understood to mean which mechanical actions are feasible. Cardiac output indicates how well the body is supplied with oxygen and nutrients. Therefore, the knowledge of the cardiac output allows to give a statement about a theoretical performance.

In addition, by using acceleration sensors in an inventive arrangement, the actual performance can be determined. By determining the movement of individual body parts, the energy converted per unit of time, ie the mechanical power, can be determined.

The comparison of this theoretical performance from the continuously measured cardiac output and the actual performance allows the prediction of the expected increase in performance during physical exercise or in rehabilitation measures.

Further, continuous motion monitoring can help in the medical application. If, during e.g. the night detects a reduced cardiac output with increased heart rate, without any significant movement is detected, the invention can draw conclusions about the diseases in question diagnostically.

In addition, an inventive arrangement provide the opportunity to measure all the different characteristics simultaneously and continuously. Therefore, an inventive arrangement can also be used for the detection of other diseases of the cardiovascular system not known to the author of this patent.

As visual representations for the users, concentric diagrams are advantageously used.

In 2D, 2.5D, or 3D, the sum of the measured data must be displayed clearly. Conventional diagrams with an X and Y axis are confusing and difficult for the user to understand for the number of views to be displayed.

The novelty is thus also to provide the measured values described here comprehensible to the user.

list of figures

• Figure 1 Illustration of the measuring method. The pulsating pressure wave (D) deforms the artery (L) evenly in time with the heart (G) as the artery (L) deforms out of its rest position (F). The pressure wave fluctuates between the values of the diastolic (B) and the values of the systolic (A) blood pressure. This has the consequence that the pressure or the pulse pressure (N) is introduced via the arterial surface (E) into the tissue (C) and continues to the skin surface (O). The blood pressure is measured by first pressing an assembly (H) with the sensors (K) on the skin (O) using a uniform pressure (J). In this case, the arrangement according to the invention can be attached to a bracelet (I).
• Figure 2 Representation of a conventional bracelet. Such a bracelet has a perforated tape (I), wherein protruding perforated tape is locked by a tab (P). The arrangement according to the invention can be carried out in the form of this tab and be used instead of this in the bracelet. This has the advantage that on the one hand the bracelet is already located at a suitable location for blood pressure measurement and on the other hand can be exercised by the adjustment of the perforated belt pressure on the sensor.
• Firgure 3 Cross-section through a possible embodiment of the inventive arrangement for use on the bracelet as an essay. The inventive arrangement is divided into two parts. The sensor unit (K), below the wristband, consisting of several tiled sensors for determining the optimal position above an artery or for determining the pulse wave velocity and a computing / radio and energy unit (H) above the wristband. The bracelet is passed through a slot (I). For measurement a uniform pressure (J) is applied from above.
• Figure 4 Electrical circuit of several sensors (shown here 7 × 15 sensors) in the crossover circuit. In this example, 15 switching lines and 7 measuring lines are required.
• Figure 5 Exemplary raw data of an arrangement according to the invention. The electronic unit provides two measuring signals. An unstrengthened signal (R) reflecting the background pressure on the sensor and an amplified signal (S) reflecting the changes in pressure.
• Figure 6 Schematic representation of the measurement of the pulse wave velocity with the aid of a sensor array (K). The two sensors (V) lie optimally over an artery (L). Both sensors are used simultaneously for the measurement. The measuring signals (W) are recorded. By examining the measurement signals for significant points, the propagation delay of the two measurement signals can be determined. The pulse wave velocity results from the transit time difference divided by the distance between the two sensors (V) to each other.

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

• EP 2337493 B1 [0007, 0018, 0019, 0020, 0023, 0025, 0027]

Claims (44)

Apparatus for the mobile measurement of characteristics of the cardiovascular system, such as cardiac output, blood pressure, cardiac output, pulse wave transit time, pulse wave velocity, pulse wave variability, respiratory rate and arterial elasticity, on an object, namely a human or animal body, using one or more pressure sensors, 1 Letter K, for measuring the energetic pulse wave. Device for measuring characteristics of the cardiovascular system according to Claim 1 is characterized in that the pressure sensors can be based on at least one FSR sensor, which changes its electrical resistance by an applied and acted upon paste or substance, pressure-sensitive. The pressure sensor may also be a further development of an FSR sensor which has a plurality of measuring ranges and which, for example, manages with fewer layers and planes than described in the previous patent specifications. As further exemplified pressure sensors also load cells or strain gauges could be used to measure the pulsating pressure wave. The use of air or gas pressure sensors in a cuff can also serve as sensors. In addition, pressure sensors based on the piezoelectric effect can also be used. Device for measuring characteristics of the cardiovascular system according to Claim 1 to 2 is characterized in that the pressure sensor for measuring the pulsating pressure wave at the body of a human or animal body, however, advantageous to the hand or the wrist, applied on the finger or on the foot, the foot and or ankle, neck, chest, neck or head or can be fastened. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pressure sensor for measuring the pulsating pressure wave can be executed both as a separate device or can be advantageously designed as an attachment for garments. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pressure sensor for measuring the characteristics attached to the human or animal body, is attached or acted upon, advantageously by means of garments such as, on the foot / ankle, ankle, for example by means of sock, stocking, shoe as measured by Puma, Nike, Boa, Reebok or shoe sole, eg., Measured on the head by means of headband, hat, for example, on the hand or wrist, by means of glove, Pulswärmer, Oberbekleidungarmgummi, eg Schaal or collar, also formed as a not fully closed clamp trained, worn jewelry and valuables, such as rings, bracelets (see 1 Letter I) and watches, watches such as those of Rolex, Tagheuer or Swatch, smart bands such as Fitbit or Jawbone, smart watches, such as Apple or LG, or else products for sports therapeutic and medical purposes, such as with a bandage, plaster, Flat tape, tape, on living object / eg. Human is attached and measures data and sends to a stationary or mobile evaluation unit Wired or by radio. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pressure sensor can be expressed or designed as a convex structure. This convex structure serves the pressure sensor for a stronger and more accurate contact pressure on the skin surface. The size of the convex structure is adapted to the measuring location and the size of the pressure sensor (s). The convex structure can be placed flexibly or rigidly according to previous claims in the direction of the skin surface or be pressed or even pressed. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that a plurality of pressure sensors for measuring the blood pressure as tiled pressure sensors, also advantageously within the convex structure, are fixed on the skin surface in order to recognize the best possible measuring position for measurement / measure up. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the tiled pressure sensor surface finds the sensor at the most optimal position independently and, if this is not possible due to a bad position of all sensors, passes on information to the user, How the user can readjust the measuring surface. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pressure sensors used advantageously, but not exclusively, based on the principle of Polymerdurcksensorentechnik. These have at least two interconnecting Leitbahnnetzt and a pressure-sensitive polymer which partially or completely resistant conductive, the resistance conductivity can also be designed pressure-sensitive. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pressure sensors used can be adapted to the measurement task. The ability of a sensor is determined by the adjustment parameters of the interconnect network and the resistance-conductive and pressure-sensitive polymer used. Apparatus for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the adjustment parameters of the conductor track network are given by the track spacing, track width and area coverage of the tracks. It is advantageous to achieve the setting of these parameters with one or more polymer layers between the interconnects and the resistance-conductive and pressure-sensitive polymer using different hole patterns and arrangements. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the adjustment parameters of the resistance-conductive and pressure-sensitive polymer are given by: - The design of an outer polymer, which builds up a defined back pressure to suppress mechanical shaking and at Relief in a defined initial state to come. - The design of a functional polymer, which can deform pressure-sensitive and thus controls the contact between polymer and interconnects. The time of deformation under stress and discharge of the functional polymer is fast enough to follow the pulsating pressure wave. The microstructure and resistance conductivity of a polymer layer for contact formation between multiple interconnect networks. In this case, the microstructure is reversibly changeable by pressurization and thereby enables a variable contact surface between the polymer and conductor tracks. The Shore hardness of the polymers used, these can either be homogeneous or differentiated by location. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pressure sensors can be calibrated by vibration motor and a continuous applied mass manually or autonomously. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that, for example, a bracelet equipped with an advantageous convex structure, above the measuring sensor, an outwardly directed pressure surface ( 1 Letter J) can be located. This pressure surface is used to absorb human energy to simultaneously direct a back pressure on the pulsating arterial vessel. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the back pressure can also be done with an actuator. This actuator can, for example, electrically, pneumatically, hydraulically, or manually by muscle contractions solve the task, or operated in combinations of anything to produce the required back pressure on the pulsating arterial vessel. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the measurement of the blood pressure can also be combined with a height measurement of the measuring point, to determine the central blood pressure. For this purpose, sensors based on pulse emission (ultrasonic or laser distance sensors) or advantageously acceleration sensors can be used. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that also several sensors, at least two sensors, at different points of the body can perform simultaneous measurements of the pulsed pulse wave. The sensors are connected directly to the device. The simultaneous use of several sensors allows the measurement of, for example, the pulse wave transit time or the pulse wave velocity. For this purpose, the signals are examined for prominent points, the temporal distance of these points divided by the spatial distance is the pulse wave velocity, cf. 6 , Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that also several devices can perform measurements of the pulsating pulse wave at different points of the body. The measured values of the pulsed pulse wave measurements are sent to a central evaluation unit, which may be, for example, a smart device, either wired or wireless. The simultaneous use of several devices allows the measurement of, for example, the pulse wave transit time or the pulse wave velocity. For this purpose, the signals are examined for prominent points, the temporal distance of these points divided by the spatial distance is the pulse wave velocity, cf. 6 , Apparatus for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that a sensor array can also be used for the determination of the pulse wave velocity. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the measuring sensors are arranged tiled, see 4 and read out crosswise as in a rolling shutter system, see model 4 , can be. This saves electrical lines and the reading of the tiled sensors can be made more variable and therefore more effective and efficient. Apparatus for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that external measuring systems for determining the heart rate can also be combined and used for the determination of the pulse wave velocity. These are, for example, ECGs or devices based on light cardiography. The prerequisite is that these devices allow a real-time measurement of the pulsating pressure or ECG wave and have an open data interface that allows a real-time output of the data. The device for measuring parameters of the cardiovascular system according to one of the preceding claims is characterized in that the device is used in conjunction with an external smart device. Device for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the device can also be designed without the use of an external smart device. For this purpose, a separate output or display unit is required. This display unit may have, among other things, an optical display element, an acoustic element or a vibration generator. A method for the mobile measurement of characteristics of the cardiovascular system, such as cardiac output, blood pressure, cardiac pulse, pulse wave transit time, pulse wave velocity, pulse wave variability, respiratory rate and arterial elasticity, on an object, namely a human or animal body, using one or more pressure sensors, 1 Letter K, for measuring the energetic pulse wave. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the measurement can be performed once or continuously. Method for measuring parameters of the cardiovascular system according to one of the preceding claims, characterized in that the counterpressure is increased to the pulsating arterial vessel by means of human power or an actuator until the measurement no longer registers a higher physical pressure from the pulsating pressure wave , A method of measuring characteristics of the cardiovascular system according to any one of the preceding claims is characterized in that to be adjusted in a continuous measurement of the counter pressure to the pulsating arterial vessel during a measurement by means of human power or an actuator in order to maintain an optimum back pressure. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the calculation of the required measured values can be carried out either in an evaluation unit or in an external device, for example a smartphone. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that calculated or raw data to an external display and computing device, for example, a smartphone is transmitted, if the device has no display capability. This is either wired or wireless, for example, based on the Bluetooth standard. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the registered maximum value of the pulsating pressure wave is the systole, 1 Letter A, represents each measured heartbeat. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the diastole can be determined by increasing the back pressure on the artery by the sensor until the maximum registered measured value just stops rising. This results in a maximum amplitude of the measured value curve. The value of the diastole corresponds to the minimas of the measured value curve at this back pressure. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the heart pulse in units of number per minute or the RR interval from the measured value curve of the pulsating pressure wave can be determined by the time interval between two successive Maximas is determined. A method for measuring characteristics of the cardiovascular system according to any one of the preceding claims is characterized in that the pulse wave variability can be determined from the RR intervals between each maximum. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the pulse wave transit time can be determined by several, at least two, pressure sensors or devices at least two measuring points on the body receive the pulsating pressure wave. The time interval between two Maximas, which are due to the same heart pulse, is the pulse wave transit time between the measuring points. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the pulse wave transit time can also be determined by the analysis of the measured values of the pulsating pressure wave. The pulsating pressure wave has a reflection wave. The time interval of the reflection wave and the initial wave is the pulse wave transit time. Method for measuring parameters of the cardiovascular system according to one of the preceding claims, characterized in that the pulse wave velocity from the pulse wave transit time with knowledge of the distance of the measuring points to each other or the distance of the measuring point to the heart can be determined. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the elasticity of the arteries can be determined from the pulse wave velocity, for example with the Moens-Korteweg formula. Method for measuring parameters of the cardiovascular system according to one of the preceding claims, characterized in that the cardiac output relative to the diameter of the aortic arch in diastolic blood pressure can be determined from the cardiac pulse, the RR interval, the measured value curve of the pulsating pressure wave, the blood pressure, the pulse wave velocity and the elasticity of the arteries can be determined. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the cardiac output can also be determined absolutely by external measurement of the diameter of the aortic arch in diastolic blood pressure. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the electrical resistance of the sensors can be advantageously calibrated in kPa and g or N. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims, characterized in that the measurement of the parameters at different measuring points of the body allow a conclusion on the central blood pressure. For this, the height difference from the measuring point to the hydrostatic indifference point (HIP) must be known. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the measurement of the blood pressure can also be combined with a height measurement of the measuring point, to determine the central blood pressure. For this purpose, sensors based on pulse emission (ultrasonic or laser distance sensors) or advantageously acceleration sensors can be used. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the parameters are also continuously and without the back pressure required as a measured value for the blood pressure measurement, is possible. The maximum arterial vessel pressure at the skin surface, plus the measured backpressure, is stored for this purpose. The maximum value measured in this way is now applied to the arterial tissue pressure on the skin surface, without, however, subjecting the contact pressure to the same as or equal to the maximum value. The continuous measurement thus takes place without additional contact pressure, but is set in percentage relative to the applied maximum value. However, this measured value is temporally volatile. Method for measuring characteristics of the cardiovascular system according to one of the preceding claims is characterized in that the parameters can also be carried out continuously during the physical movement of the person to be examined or the animal to be examined. This requires a firm loading of the sensor on the body and the knowledge of the height of the measuring point to the HIP. Advantageously, a measuring point on the back of the foot is used in humans, since there are only slight height changes in, for example, running.

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