HK1249062B - Medical product comprising a functional element for the invasive use in a patient's body - Google Patents

Description

Medical products with functional elements that are invasively placed in the patient's body

The present application is a divisional application of application number 201280043213.1 filed on September 4, 2012, and the invention name is "Medical product with functional elements for use in a patient's body."

Technical Field

The present invention relates to the field of medical engineering, and in particular to the field of micromechanics and medical measurement technology.

Background Art

Modern medicine uses minimally invasive techniques in a variety of ways and at increasingly higher levels to achieve maximum support, treatment or diagnostic success with minimal harm to patients.

Examples of these technologies include implanting stents within blood vessels, using thrombus filters, removing deposits within blood vessels through milling, and supporting or temporarily or partially replacing a patient's heart function through the use of micropumps/blood pumps introduced into blood vessels. Many of these technologies require that appropriate functional components be introduced into the patient's body through the bloodstream via a catheter and placed in the bloodstream in the most appropriate manner.

The most precise possible control of the position is not only desirable in initial and emergency use, for example, of a milling head, but is also decisive for the success of invasive measures in the long term.

Positioning is particularly critical for blood pumps, as these often remain in the patient's body for extended periods and must operate stably without constant supervision by medical personnel. Catheter configurations, particularly those accessed through the femoral artery, present a risk of displacement due to active or passive body movement. Strict precision is required for blood pump placement, particularly when these pumps are located near or in conjunction with heart valves.

The position of the relevant functional elements is usually analyzed using radiofluoroscopy or transesophageal echocardiography. However, these methods require complex equipment that is not always available. This makes positioning not only complicated and expensive, but also not practical or useful in many situations given the extreme time pressure. In emergency situations, an intra-aortic pump can be placed blindly by measuring the distance between the groin puncture point and the neck notch. However, this presupposes a normal anatomical environment and is accompanied by the risk of misplacement of the contralateral femoral artery. Because the individual aortic anatomical characteristics are unpredictable, this method is also imprecise. If the functional elements, especially the pump, are not placed optimally, the support effect of the pump is not optimal and the other functional elements will also not function optimally.

Besides pure fluoroscopic methods, other options known from the prior art for positioning of components, and more particularly of cardiac catheters, are substantially more precise.

US Patent 5,983,126, for example, discloses the application of three orthogonal external signals outside the patient's body to a localized area, wherein a probe is used to detect the effects of the three signals on a functional element and thereby determine the location. The external signals must be designed so that they do not interfere with the electrophysiological signals of the heart.

US 6,226,546 B1 describes a method for positioning a catheter using a plurality of acoustic probes at the catheter head, wherein signals emitted by the probes are received by an acoustic receiver and processed by a processing unit to determine the position and delineate the anatomical environment of the probes.

US Pat. No. 5,391,199 discloses a method for positioning a catheter with an accuracy of approximately 1 mm, wherein a transmitter outside the patient's body emits signals via an antenna, and receiving antennas are provided at the end of the catheter, which are connected to receivers for processing the signals. These signals are compared with corresponding reference signals from a reference antenna inside the patient's body.

US Pat. No. 6,892,091 B1 discloses a device and method for recording and mapping electrophysiological activity in the heart using a cardiac catheter. The corresponding catheter also includes a position sensor designed as an electromagnetic sensor. An exemplary embodiment of using the position sensor includes applying a magnetic field generated outside the patient's body and applying this magnetic field to the position sensor, so that the sensor, and thus the catheter, can detect its position and orientation. Furthermore, a comparison with a reference signal from a separately introduced catheter is described.

The methods known from the prior art all require complex equipment in the form of imaging devices or additional signal sources outside the patient's body. These methods are not suitable for daily use, which would be fine, nor do they allow the blood pump to operate for extended periods of time to support the heart without the supervision of medical personnel.

Summary of the Invention

The object of the present invention is to provide a medical product which allows simple and reliable positioning during invasive use of a blood pump and which has a particularly low-complexity device.

According to the invention, this object is achieved by the features of claim 1 , 9 or 14 .

The invention makes it possible to control the position of a blood pump over days, weeks or months, even when said blood pump is running automatically and even in the event of regular movements of the patient.

In a variant of claim 1, the medical product includes a functional element in the form of a blood pump for invasive application in a patient's body, the functional element having a main sensor in a fixed spatial relationship to the blood pump. In particular, the main sensor is at a fixed, known distance from the blood pump. Furthermore, a processing unit is provided that receives a signal from the main sensor, the main sensor displays the signal or a reading obtained by the main sensor, and determines at least one variable representative of the position of the blood pump from the signal from the main sensor based on electrophysiological signals of the heart.

Measuring electrophysiological signals on a beating heart has long been known. A typical application is conventional electrocardiography using electrodes, an appropriate number of which, depending on the type and complexity of the leads, are placed on the patient's skin.

The time-varying signals are conventionally processed to form a vector of fingerprints characteristic of each individual heart.

Since the individual electrophysiological signals recorded are strongly dependent on the location of the leads, a comparison between the measured signals and a typical electrocardiogram of the same person allows the location of the measurement/leads to be determined. Alternatively, the location of the individual measurement electrodes can also be determined.

For this purpose, the invention comprises a corresponding processing unit which is directly connected to the electrodes or which is able to obtain suitably preprocessed data directly from the ECG electrodes.

If the signals recorded by the main sensor are compared or linked continuously or periodically with the electrophysiological data of the heart, the position of the main sensor and, therefore, the position of the functional element/blood pump, which has a fixed spatial relationship to the main sensor, can be monitored on an ongoing basis. In a particularly simple design, the main sensor is, for example, arranged on the blood pump itself or at a fixed distance from the blood pump, for example, at one end of the pump if the blood pump is designed as a substantially elongated body.

The method can similarly be applied using impedance measurements or by comparing the pulse curve detected by the primary sensor with readings from a corresponding peripheral artery (e.g., an arm or leg artery). Here, the time delay between the maximum and minimum pressure increase is determined, which indicates a change in position or a change in circulatory characteristics.

In a particular embodiment of the present invention, the processing unit can be directly connected to an auxiliary sensor that records appropriate electrophysiological cardiac signals, and the processing unit can further process the signal from the primary sensor using the currently detected signal from the auxiliary sensor or data determined therefrom, for example, if the data has already been pre-processed to obtain an ECG. This procedure has the advantage that, for example, the temporal rhythm of the signal detected by the primary sensor can be directly synchronized with the temporal rhythm of the signal from the auxiliary sensor.

The vectors of the signals obtained by the main sensor and the limb leads, for example with respect to a particular limb lead according to the technique described by Goldberger, can then be used to define an optimal position vector. The vector can be continuously compared with the ECG vector obtained by the main sensor, whereby for each heartbeat the actual position of the main sensor, and therefore the position of the functional element, can be detected and compared with the expected position. In this regard, the measured vector data and the data detected by the main sensor can be recorded and calibrated using a variety of known positions of the main sensor and/or functional element/blood pump (e.g., simultaneously using imaging methods), and whereby a "map" of the position can be stored based on example data and can be compared later with the currently detected data. For example, the data record that is closest to the currently detected data record can be determined, and the position data stored for this closest data record can be used to depict the current position result of the main sensor and/or functional element.

The processing unit can also be connected to a storage unit, which stores pre-detected electrophysiological cardiac signals, especially electrophysiological cardiac signals of a patient's heart, and the processing unit can couple the signal from the main sensor with the stored cardiac signal and/or other pre-detected data, or data determined therefrom, to determine a variable representing the position of the functional element.

For the purpose of comparison with stored ECG data, a temporal scaling of the data currently acquired by the primary sensor is necessary, or at least advantageous, before comparing the currently acquired vector or the currently acquired data with the stored ECG data.

It is also conceivable to establish a relationship between stored reference ECG data and currently acquired ECG data from the auxiliary sensor and to acquire data on this basis, which are compared with the signal from the primary sensor.

The primary sensor typically includes electrodes and/or antennas for recording electrophysiological signals. Within the patient's body, these signals propagate electrokinetically and galvanically, enabling accurate recording even at significant distances from the heart. The coupling between the associated electrodes and the measuring circuitry, whether these are measuring electrodes or antennas, plays a decisive role in the resulting frequency response.

Advantageously, more than one electrode or antenna can be provided on the primary sensor. For example, two electrodes/antennas spaced apart from each other can yield a more accurate determination of position and orientation. However, the use of more than two electrodes is also conceivable. Thus, a multidimensional vector can be obtained from the data detected by the primary sensor.

The present invention can be particularly advantageously implemented using a blood pump that can be moved along a blood vessel via a catheter. Regarding blood pumps, which are typically used outside the heart but can also be used inside the heart, the distance relative to the inlet or outlet of the ventricle or the position along the blood vessel is crucial for successful use and is of particular concern.

A typical functional element according to the invention may be a blood pump, and more particularly an intra-aortic balloon pump or a rotary pump.

The position relative to the ventricle is very important for the blood pump. An intra-aortic balloon pump, for example, must be placed outside and in front of the ventricle at a given distance, while a rotary pump should partially extend into the ventricle.

In this regard, according to the invention, the variable representing the position of the functional element may be the distance from the orifice of a blood vessel in which the functional element enters the ventricle, in particular in the direction of the blood vessel in which the functional element enters the ventricle.

According to a specific embodiment of the present invention, the main sensor may also include a sensor for detecting a fluid dynamics variable, in particular a pressure sensor or a blood flow rate sensor, or the main sensor may be such a sensor, and the processing unit is capable of detecting the temporal relationship between the currently detected electrophysiological cardiac signal and the measured value representing the blood flow at the location of the main sensor, and determining the variable representing the position of the functional element based on this relationship. In this case, the position of the main sensor or the functional element formed by the blood pump is determined primarily by utilizing the delay of flow modulations generated by cardiac activity, and in particular the delay of flow rate changes or pressure changes in the blood circulation system.

Because the electrophysiological signal is recorded with little delay, the excursion of the pressure wave occurs relatively slowly. When the excursion rate is known, the time delay of the maximum pressure wave can be used, for example, to calculate the distance from the heart to the primary sensor. Instead of the pressure wave maximum, other typical pressure wave points in the vascular system can also be used.

Another advantageous embodiment of the present invention relates to a medical product, wherein the processing unit detects a variable representing a change in the position of the functional element and generates a signal, in particular an alarm signal, when this change exceeds a threshold value. (In the present invention, "exceeding" is to be understood as any interesting deviation from the threshold value, i.e., a deviation below or above a specific threshold value). When the alarm signal is issued, the patient can seek medical assistance or adjust the brakes independently or automatically.

Another advantageous embodiment of the present invention relates to a medical product, wherein the processing unit comprises a storage unit for the detected position of the functional element, and a comparison unit which compares the continuously detected position values of the functional element with the stored value in the storage unit, determines the difference between the stored value and the currently detected position value, and emits a signal when the difference exceeds an established threshold value.

According to another embodiment of the present invention, the processing unit is advantageously connected to a unit that generates a signal representative of the current power of the blood pump. In particular, if the blood pump is a rotary pump, the processing unit is connected to a unit that generates a signal representative of the rotational speed of the blood pump, and the processing unit comprises a correction unit for taking the power of the blood pump into account when determining the position of the functional element.

In particular, the rotational speed of the rotary pump can influence the heart function and thus the signal used to determine the position. The influence of the rotational speed can therefore advantageously be detected, stored in characteristic fields, and taken into account in the evaluation.

The invention further relates to a medical product, which has been partially described above by way of example, and to a method for operating a blood pump in a patient's body, in particular in a blood vessel, characterized in that a variable representative of the position of the blood pump is detected by a main sensor having a fixed spatial relationship to the blood pump by: locally detecting at least one parameter defined by the patient's cardiac function and converting the parameter into a signal, and coupling the same data or signal or other data or signals representative of the cardiac function with the signal from the main sensor, the same data or signal or other data or signals being detected, for example, in the same blood vessel in which the blood pump is placed, at a known position away from the blood pump.

Advantages of the present invention also relate to a method for operating a blood pump, wherein the blood pump is first placed at a predetermined position in a patient's body using an imaging method, characterized in that, thereafter, according to the method according to claim 14, a variable representing the position of the blood pump is detected and stored as a calibration variable, and then the method according to claim 14 is performed and the detected variable representing the position of the blood pump is compared with the calibration variable and a signal is issued when the change relative to the calibration value exceeds a threshold value.

The signal may be a visual and/or audible alarm signal that can be directed to the patient or medical personnel, or can directly instruct the device to adjust the pump.

In an advantageous embodiment of the invention, the processing unit is designed to process signals from an impedance sensor and/or a blood pressure sensor and/or a respiratory activity sensor and/or a sensor for the oxygen content in the blood, and/or is connected to one or more of these types of sensors. By coupling one or more of these measured variables with the signal or measurement result detected by the main sensor, the position of the main sensor can be determined directly or by comparison with stored reference data. The main sensor can also be adapted to detect the aforementioned measured variables, such as impedance, blood pressure, respiratory activity, or oxygen content.

According to one embodiment of the invention, the auxiliary sensor, similar to the main sensor, includes variables representative of blood flow, and more particularly, includes variables also measured by the main sensor, and is arranged at a position, in particular, at a known position, which is separated from the unknown position of the main sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described by way of exemplary embodiments and shown in the following drawings.

In said drawings:

FIG1 is a schematic diagram of an intra-aortic balloon pump in a blood vessel close to the heart, wherein the balloon of the balloon pump is in a compressed state;

FIG2 shows the configuration of FIG1 with an inflated balloon;

FIG3 is a schematic diagram of the upper body of a patient with electrodes for recording ECG signals and an intra-aortic balloon pump including a main sensor;

FIG4 is a schematic diagram of a blood vessel having a functional element, a primary sensor, an auxiliary sensor, and a processing unit;

FIG5 is a schematic diagram of another processing unit;

FIG6 is another embodiment of a processing unit;

FIG7 shows another embodiment of the medical product of the present invention, comprising a pressure sensor forming the main sensor;

FIG8 shows yet another alternative embodiment of the present invention for determining the position of a functional element;

FIG9 shows an example of an implantable heart pump including a rotor as a functional element;

FIG10 shows a medical product comprising a blood pump and a processing unit for position monitoring and an alarm system.

DETAILED DESCRIPTION

FIG1 is a schematic diagram of a portion of a heart having a left atrium 1, a left ventricle 2, blood vessels 3 extending from the left ventricle 2, and heart valves 4 that allow blood to flow from the left ventricle 2 into the blood vessels.

FIG1 shows the state of the cardiac systolic phase, wherein the balloon pump 5 is in a compressed state. In this case, the balloon pump 5 forms the functional element, which can be used to support the heart by relieving the left ventricle in the event of acute heart failure, coronary heart disease, and the like. The intra-aortic balloon pump can be used in coronary artery bypass grafting surgery to treat cardiogenic shock and acute myocardial infarction, as well as in acute myocarditis, cardiomyopathy, and acute left ventricular failure. It is typically advanced from the femoral artery into the aorta and then positioned so that the end of the pump catheter is positioned at the end of the aortic arch. The balloon is typically filled with 40 ml of helium over a length of 20 cm and thereby inflated. The balloon is periodically filled and emptied (compressed) by an external air pressure system. Because the filling and emptying of the balloon is opposite to the cardiac activity, the afterload of the left ventricle is reduced during cardiac systole, which improves the ejection fraction and reduces myocardial oxygen consumption.

The diastolic filling of the balloon of the pump, as shown in FIG2 , displaces an average of 40 ml of blood, thereby increasing diastolic pressure and organ blood flow, and at this stage, increasing organ blood flow, especially coronary blood flow.

In this context, it is crucial to position the functional element in the aorta as best as possible relative to the heart valve 4 or the vascular opening into the left ventricle.

In this regard, as shown in FIG3 , the present invention relates to a main sensor 6, which in the illustrated embodiment is arranged at the end of the balloon pump. However, in any case, the main sensor is arranged in a fixed spatial relationship, for example, at a fixed, known distance relative to the balloon pump or directly on the balloon pump, and allows the detection of electrophysiological signals of the heart or of hydrodynamic variables of the ejected blood flow. The main sensor is, for example, designed as an electrode or antenna, or includes an electrode or antenna, depending on the internal circuit.

In addition, auxiliary sensors 7, 8, 9, 10, 11 are provided, which can be formed by electrodes for performing ECG measurements outside the patient's body. Alternatively, differently positioned sensors are conceivable, for example, sensors as part of an implanted device, not arranged on the body surface but inside the body, suitable for recording electrophysiological cardiac signals. Such sensors can be provided, for example, in a pacemaker or an implanted defibrillator. It is also conceivable to provide a smaller number of auxiliary sensors, for example, one, two, three or four auxiliary sensors, wherein a larger number of auxiliary sensors allows for the acquisition of more complex ECG vectors, which makes the positioning of the main sensor, and thus the positioning of the functional element 5 (by comparison and coupling with the signal of the main sensor 6), more precise.

The main sensor 6 and the auxiliary sensors record the time curve of the respective electrophysiological heart signals or other measured variables so that the position of the main sensor can be detected by comparing and coupling the signal from the main sensor with the signals of the remaining auxiliary sensors having multiple positions.

In addition to the functional element 12 (which may be a rotary pump), for example the main sensor 6 located at the end of the functional element, and the auxiliary sensors 7, 8, 9, 10, 11, Figure 4 shows a processing unit 13 in which the signals from all sensors are combined.

For ECG data, the signals from the auxiliary sensors are combined to form a vector, while the time-varying signal from the main sensor 6 is present as a scalar _f1 (t). The vector of signals from the auxiliary sensors is compared with the function _f1 (t) to determine the position of the main sensor 6 using pre-detected metrics in the processing unit 13, and the result is displayed on the display device 14. To this end, the absolute position of the functional element 12 entering the left ventricle from the inlet or the interval along the blood vessel 3 can be displayed on the display device.

FIG5 shows another alternative embodiment of the processing unit, in which the currently detected electrophysiological signal is not detected by an auxiliary sensor but using stored data, which data is stored in the storage unit 15 of the processing unit 13′ and, for example, is measured when starting treatment of the patient and archived, so that the position of the functional element can be detected later by comparing the currently detected signal from the main sensor with a typical signal of the patient's heart.

FIG6 illustrates a variant of the present invention in which both the currently detected electrophysiological cardiac signal and the stored ECG data are coupled to the signal from the primary sensor. To this end, as in the embodiment shown in FIG4 , the signal from the primary sensor can be recorded by a plurality of primary sensor elements independently distributed across the functional element 5, enabling the primary sensor to also detect a signal vector. The currently detected electrophysiological cardiac signal is then first compared with the stored data, and the comparison result is coupled with the data detected by the primary sensor to output position information on the display unit 14 using a metric. Thus, a traffic light-like indicator can be provided, in the form of a green light for the absolute distance from the ventricle to the functional element or a permitted distance range, a yellow light for a critical distance range, and a red light for a prohibited distance range. Alternatively or additionally, the position can also be represented graphically, for example, by its position relative to the heart or relative to a reference point, such as an auxiliary sensor, whose position is particularly precisely known. Furthermore, the position can be indicated by an acoustic signal, such as an alarm signal, indicating a deviation from the expected position or a change in distance from a predetermined location.

Figure 7 shows another design of a medical product according to the invention, in which the heart (which is symbolically represented by the number 16) simultaneously emits electrophysiological signals, which are recorded by one or more auxiliary sensors 7′, and blood pressure fluctuations are transmitted through the vascular system due to periodic pump activity, wherein the fluctuations are recorded by a pressure sensor 6′, which is located at the end of the functional element 5, such as a heart pump.

Because the electrophysiological signals recorded by sensor 7′ are virtually undelayed, these signals convey a current picture of the heart's activity, which can be compared with the blood pressure fluctuations that arrive at the main sensor 6′ with a delay due to the slower excursion rate. It is possible to determine or know when the highest or lowest blood pressure occurs in the heart during a complete cardiac cycle, so that the excursion rate of the pressure wave can be known, and the distance from the ventricle to the main sensor 6′ can be obtained from the time difference recorded by the sensors 6′, 7′. Using this display configuration and the corresponding processing unit 13′″, the position of the main sensor 6′, and therefore the position of the functional element 5′ relative to the vascular system in the heart, can be determined and displayed.

The measurements are usually performed based on the maximum achievable blood pressure. When the functional element 5' is introduced, the measurements by the processing unit 13'" can be calibrated, for example, by slowly inserting it into the blood vessel while determining the position of the functional element 5' by imaging methods.

FIG8 shows another alternative medical product according to the invention, in which a main sensor 6″ is arranged at the end of the functional element 5″ and interacts with a plurality of, in particular two, three or four, auxiliary sensors or transceivers 17, 18, 19, 20, for example, via magnetic, electric or electromagnetic coupling. The respective transceiver can also be used as the main sensor 6″, so that it can transmit signals received from the element 17, 18, 19, 20 and vice versa. The coupling strength of the element 17, 18, 19, 20 with the respective element 6″ can be used to determine its position relative to the element 17, 18, 19, 20. For example, electrodes that already exist and are alternately used for positioning and as ECG electrodes can be used as transceiver elements 17, 18, 19, 20.

The plurality of coupling strengths are coupled in the processing unit 13 ″″. In this case, for example, a plurality of sensor elements can be arranged on the main sensor in order to achieve a more accurate positioning or to additionally enable the direction of the functional element to be detected.

FIG9 shows an example of a rotary pump 30 as a functional element, which is designed to be compressible and expandable to be embedded in a ventricle 31. The pump 30 comprises a rotor 32 with a hub 33, which can be driven from outside the patient's body by a drive shaft 34. The drive shaft is guided by a hollow catheter 35 (which is only partially shown). The pump 30 comprises a compression pump housing 36, to the proximal end of which a main sensor 37 is connected. The main sensor can be connected to a processing unit arranged outside the body, for example, via an electrical conductor located in the lumen or the wall of the hollow catheter 35, in particular via the drive shaft.

During operation, the pump draws blood through an intake cage 38 and ejects it into a blood vessel 40 through a nozzle 39. A resilient outflow tube 41 is provided which cooperates with a heart valve surrounding the outflow tube to periodically close the ejection/outflow port 39 and thereby prevent backflow of blood.

This demonstrates that the position of the pump relative to the heart valve must be precisely determined.

If the position of the main sensor 37 can be detected, the position of the pump 30 in the ventricle can be accurately determined.

In one variant, another sensor 37 is connected to the distal end of the pump housing. In this case, the correlation signal between the two sensors, for example an ECG vector, can be directly determined, and the position or change in position of the pump can be derived therefrom. In this case, depending on the required accuracy of positioning, additional, in particular external, auxiliary sensors as described above can be used.

The operational performance of the blood pump can also be used to implement a main sensor for measuring fluid dynamic variables, such as the blood pressure or flow rate of the blood, for example, in the case of a rotary pump, if the drive power/torque is known, the current rotational speed can be used, or the drive torque, drive power, or current/voltage/electrical power of the drive motor of the pump.

The current rotational speed and electrical power required for driving purposes can be determined based on the drive current required to drive the motor, and can be used to detect the blood flow rate through the pump in a time-resolved manner. As the heart beats, it produces a periodic pattern, the phase angle of which can be compared with ECG data to determine the delay in fluid dynamic changes from the heart to the primary sensor, and thus determine the distance from the heart to the primary sensor.

It is also possible to position two sensors in the same blood vessel and use travel time measurements (based on the measurement of fluid dynamic variables by each sensor) to determine the distance or change in distance between the two sensors. If the position of one of the sensors is fixed and/or known, the absolute position of the other sensor can be determined and monitored.

FIG10 shows a patient's body, wherein a heart 43 is supported by a blood pump disposed in a heart valve via a catheter 44. Sensors are disposed on the blood pump, and their signals are transmitted via a wire 45 extending along, and particularly within, the catheter 44. Signal detection is performed in a signal detection unit 46, which may alternatively or additionally receive radio signals and signals from sensors located in an area external to the patient, such as ECG electrodes. A signal monitoring unit 47 monitors trends in the monitored signals and/or compares them with reference signals to detect differences from and/or threshold values exceeded. If a significant change or alteration in the position is detected, a signal is transmitted to an alarm system 48, which communicates with the outside world and can optionally initiate adjustment of the blood pump's position. During the adjustment process, the elimination of the alarm signal can be considered an indication that the desired position has been reached. In the event that less than ideal methods are used to achieve the desired positioning, the processing unit may also include a calibration system 49 for detecting and storing reference data.

The medical product described in the present invention can be used to visualize the signals of the main sensors 6, 6', 6" to optimize the positioning during implantation, making replacement of the medical product in the circulation easier and safer. The visualization can be achieved on a screen of a user console, which is configured to display the position of the medical product in the body of a human or animal. The screen can be a touch screen, which is configured to display and control the medical product during use. The visualization is particularly advantageous in controlling the position of the medical product in the blood circuit. For example, the position of the rotary blood pump relative to the heart valve (see, for example, Figure 9 of the present application) can be easily controlled by medical personnel, and any necessary calibration can be performed by repositioning the medical product according to the vector displayed on the above screen.

Claims (10)

1. A medical product comprising a blood pump invasively used in a patient's body and a main sensor having a fixed spatial relationship with the blood pump, characterized in that the main sensor generates a signal representing the current electrical power of the blood pump, the medical product further comprising a processing unit that receives the signal from the main sensor and compares the phase angle of a periodic pattern of the signal with ECG data to determine the distance from the heart to the main sensor; The processing unit is characterized in that it receives the signal from the main sensor and determines at least one variable representing the position of the blood pump based on the first electrophysiological cardiac signal from the auxiliary sensor or stored in the storage unit. 2. The medical product according to claim 1, wherein the processing unit includes a correction unit for taking into account the current electrical power of the blood pump during the process of determining the position of the blood pump. 3. The medical product according to claim 1, wherein the blood pump is a rotary pump, the main sensor generates a signal representing the rotational speed of the blood pump, and the processing unit determines at least one variable representing the position of the blood pump based on the first electrophysiological cardiac signal and the signal representing the rotational speed of the blood pump from the main sensor. 4. The medical product according to claim 3, wherein the current electrical power or rotation speed of the blood pump is used to determine the flow rate of blood through the blood pump, and the processing unit determines the delay of the hydrodynamic change from the heart to the main sensor based on the first electrophysiological cardiac signal, and thereby determines the distance from the heart to the main sensor. 5. The medical product according to claim 1, wherein the main sensor is a pressure sensor for detecting the measured value of blood flow, and the processing unit detects the time relationship between the first electrophysiological cardiac signal and the measured value of blood flow representing the location of the main sensor, and determines a variable representing the location of the blood pump based on the relationship. 6. The medical product according to claim 1, wherein the main sensor further detects a second electrophysiological cardiac signal, and the processing unit compares and couples the second electrophysiological cardiac signal with the first electrophysiological cardiac signal to determine the at least one variable representing the position of the blood pump. 7. The medical product according to any one of claims 1-6, characterized in that the processing unit is designed to process signals from an impedance sensor and/or a blood pressure sensor and/or a respiratory activity sensor and/or a sensor for oxygen content in the blood, and/or the processing unit is connected to one or more sensors of the above types. 8. The medical product according to any one of claims 1-6, characterized in that the processing unit detects changes in a variable representing the position of the blood pump and generates a signal when the change exceeds a threshold. 9. The medical product according to claim 8, wherein an alarm signal is generated when the change exceeds a threshold. 10. The medical product according to any one of claims 1-6, characterized in that the processing unit includes a storage unit for the detected blood pump position and a comparison unit that compares the continuously detected blood pump position value with the stored value in the storage unit, determines the difference between the stored value and the currently detected position value, and issues a signal when the difference exceeds an established threshold.