DE3101800A1 - DEVICE FOR LONG-TERM MONITORING AND STORAGE OF SIGNALS RESULTING FROM HEART ACTIVITY - Google Patents

Description

MEDTRONIC, INC.

3055 Old Highway Eight, Minneapolis, Minn. 55440

V.St.A.

Device for long-term monitoring and storage of cardiac activity Signals

The invention relates to a device for long-term monitoring and storage of cardiac activity declining electrical signals from a patient.

It is often desirable to have a record of cardiac activity, and particularly cardiac activity, for outpatients Establish ECG over relatively long periods of time ("The Use of R-R Interval and Different Histograms in Classifying Disorders of Sinus Rhythm "by P. M. M.

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Cashman, Journal of Medical Engineering Technology, January 1977). The main goal of such records is to be able to identify infrequent and temporary disorders of the heart rhythm. This can be especially true when diagnosing patients with indistinct or intermittent Symptoms such as dizziness, loss of consciousness and fainting spells can be important. During the recording If done over a longer period of time, the doctor is interested in short, specific ones Identify arrhythmias that are only a small one Take as a percentage of the total recording time. Such rhythm disturbances are called singularities to address in a background rhythm. Typically, the doctor is not only interested in the background rhythm, but also interested in the specific arrhythmia, which is a slower one Response of the heart to influences such as drug treatment or psychological stress over a long period of time Periods of time, can act. In this regard, it may be desirable to keep long-term records either from different patients or from the same patient at different times with each other to compare.

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The use of outpatient cardiac monitoring devices, such as the Holter recorder, is known. After the Holter procedure, the patient's EKG activity is typically recorded over a period of at least 24 hours. The difficulty with using a Holter writer is that it creates a large volume of information that must be processed and analyzed. Such analysis is usually time consuming and costly. Review and processing time can be reduced if the data is read out and played back at increased speeds, typically multiples of 25, 32, 60 and 120 times the normal playback speed. In order to reproduce the heart data, and in particular the QRS complex, with sufficient clarity, it may be necessary to use recording devices which have a frequency range up to over 12 kHz. You can do this with ultraviolet pens, fiber optic writing oscilloscopes, or inkjet pens, all of which are expensive.

Various devices for processing and displaying cardiac activity data are also available.

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knows. Such devices can use a detector have automatic detection of a dysrhythmia and, depending on this, a sample of the patient's EKG and display them either immediately on paper or on a screen. Further a contourogram can be produced using a storage oscilloscope or an instant camera, taking consecutive parts of the patient's EKG are displayed one below the other. Each such segment or track piece is proportional to the interval from beat to beat, and the right edge of the track provides a continuous record of the RR interval trends. One of the most common procedures The presentation of EKG data consists in determining a heart rate trend, with the RR interval is constantly measured and the RR interval data in continuous time periods are segmented. In particular the rate or interval of the heartbeat is averaged to give an indication of the mean Heart rate or mean interval for a number of consecutive time periods. To resolve individual beats in a trend recording, it can be useful to use the instantaneous rate to be plotted in the form of a trend record.

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It is also required to identify the isolated occurrence of an anomalous or ectopic stroke and highlight. Typically, the ectopic beat occurs during the course of the cardiac monitoring period recorded and counted. Devices have been developed to detect a premature heartbeat. The degree of Prematurity can often be preset by the operator in order to allow for a selection of the beats to be recorded care for. The output signal of such detectors is depending on the desired application of a counting circuit, fed to a trend recorder or an alarm device. Various measures were used to detect the abnormal shape of the patient's EKG signal. So became simple integrators, filters and digital ones Pattern recognition systems used. Normal ECG signals are analyzed to determine the limits of occurrence of the peaks of the QRS complexes and such Compare limit values with the incoming signal so that it can be determined whether the present EKG signal is within these predetermined, normal limits.

In more advanced systems, the patient's normal EKG signal is recorded and stored. In the course of the subsequent monitoring, the normal signal

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nal of the patient is used as a template with which the ongoing heart data are compared. So a heart monitor is known (US-PS 4,115,864) in which a computer is used to control the storage of the patient's normal signal, the input Process EKG signal into digital segments and these segments with corresponding segments of the previously stored compare the patient's normal EKGs. If the stored normal signal does not match the ongoing signal matches, an alarm device or a detector circuit is actuated. The number the occurrence of this ectopic signal is stored in the memory of the computer. By means of this device can be a trend of such ectopic beats in the form of a histogram or a trend curve to be determined.

Whenever ECG data is processed, it is necessary to apply discriminatory measures in order to generate a trigger pulse pull out for each cardiac cycle. In most cases, the detector circuit speaks on the R-WeI-Ie so that it becomes necessary to distinguish the R wave of the QRS complex from the rest of the signal. In the presence of strong background noise it will be necessary to continue monitoring for the duration of the

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to interrupt strong background noise. In other cases the detector circuit can trigger an alarm, so that the operator can intervene.

If you want to ensure long-term monitoring of the patient's cardiac activity, the continuous Monitoring by means of the Holter monitor a complete record at relatively low Costs. However, processing and compressing the data for easier, more limited rendering does often a more complex, costly setup is required. To overcome these difficulties, was suggested the data in the form of an RR interval histogram according to FIG. 1. A histogram gives the cardiac activity data over a period of time away again in a compact manner, with the successive intervals between R-waves being calculated and classified according to their duration. As can be seen from Fig. 1, the RR interval is plotted in seconds on the X axis, while in direction the Y-axis indicates the number of beats that occur within each interval. Such a representation ensures a great data reduction in a descriptive way that allows easy comparison between the histograms of the same patient that too

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different times as well as between different patients allowed. The RR interval histogram (IH) is formed by creating a series of columns (bins), each of which is an area of values of the interval from beat to beat (RR interval) is equivalent to. When each EKG complex is acquired, the time interval between that complex and the previous complex measured; the total value of the corresponding bin is incremented. A typical histogram may have 100 bins, each 20 ms wide, giving a total range of RR intervals from 0 to 2 s results. A bin capacity of 4095 beats (a 12-bit binary word) allows for a normal Heart monitoring for about 4 hours.

A modification of the RR interval histogram is that in Figure 2 illustrates RR interval difference histogram (IDH). The interval difference histogram becomes more similar Manner, with the exception that the quantity plotted along the X-axis, as shown in Fig. 2, is the amount by which the RR interval is increased changes between successive beats. How out As can be seen from Fig. 2, the middle bin is denoted by 0, i.e. difference 0 between successive ones Beat. 100 pillars lead to an area that extends

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extends from -1 s over 0 to +1 s, with a bin width of 20 ms. The mean of the interval differences is always very close to 0. The interval difference histogram provides an indication of the type of change in heartbeat, with the width of the histogram is a measure of the distribution of heart rates around the mean. Both the interval histogram and provide the interval difference histogram for the doctor a valuable tool in diagnosing the patient's heart.

An implantable device is also known (US Pat. No. 4,146,029), by means of which medicaments are delivered to the patient's body. The device has a microprocessor for process control on. Each QRS complex of the patient's heart is recorded and measured for the length of the QRS complex and the interval between such complexes is evaluated. It is a comparison program the length of the QRS complex with an acceptable length provided to validate each QRS complex to determine and further first to calculate the interval between QRS complexes and the measured Compare length to a known or standard length for a particular patient. Especially

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In particular, a length comparison is made to determine how much shorter the measured running intervals are than the normal length. Depending on the decrease in length, i.e. the increase in the heart rate, caused the microprocessor controls the dispenser to change the dosage for the patient. It will RR interval measured and the mean value of the RR interval Accumulated over a predetermined period of time, for example 1 hour. The averaged RR intervals are compared with known standard values in order to variably control the drug delivery to the patient.

The invention is based on the object of a novel and improved device for monitoring and storage of cardiac activity signals using a data processor, for example in the form of a digital microprocessor. The data processor is intended to provide signals in a particularly effective way, which are characteristic of the patient's heart signals, evaluate and store.

According to the invention, this object is achieved by a device solved with the features of claim 1. The device has a memory with a first and a second Plurality of storage locations. It's one in one

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Real-time frame working circuit arrangement provided, which the cardiac activity of the patient with a polls regular rate and the polled signals in corresponding locations of the first plurality of memory locations stores. The device is also equipped with a data processing device, which processes the signals stored in the locations of the first plurality of memory locations and stores the processed signals in the selected locations of the second plurality of storage locations. the The signals are preferably stored in the second plurality of memory locations in a second Computer time frame and at a speed that is higher than the real-time query speed. That This means that the patient's heart signals are queried in a first, relatively slow real-time frame, while the processing and evaluation of the interrogated heart signals in a second, relatively rapid Computer timeframe. This greatly simplifies data storage and display.

According to a further development of the invention, an interrogation clock generator is provided which is sent to the interrogation circuit, by means of which the samples of the

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Cardiac activity of the patient are detected, provides an interrogation clock signal. A computer clock generator gives computer clock signals to at least part of the data processing device, so that the processing of the cardiac activity signal takes place in the relatively rapid computer time frame.

According to a further feature of the invention, the data processing device has an evaluation stage, which, depending on the interrogation clock generator signal, evaluates the cardiac activity signals to determine whether they are present to determine a valid heartbeat. Corresponding In one embodiment, segments of the cardiac activity signals are included in the evaluation of the cardiac activity signals Signals determines what to check for a sequence of such segments to see if a valid Heartbeat was monitored.

The data processing device is preferably further equipped with a stage that operates in the computer time frame and processes the recorded heartbeat and especially that between consecutive Heartbeats and the heartbeat rate is determined from it. The manifestations of the intervals between successive heartbeats and the heart

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beat rate are stored in another location in the memory. This stored data is evaluated to see if the heartbeat is occurring with a regular rhythm, or if not, one There is an anomaly. If such an anomaly is detected or the patient via a hand-operated one Switch has given an indication of an anomaly or heart complaint, the data processing device transfers a sequence of the interrogated heart signals in a further memory section, where the signals for a subsequent readout and playback can be stored.

The invention is preferred below by way of one Embodiment explained in more detail. In the drawings show:

Figs. 1 and 2 histograms of the RR interval and

the interval differences over an extended period of time,

Figs. 3A and 3B are a functional block diagram of FIG

basic building blocks of the heart monitor according to the invention or a perspective view of the in the device

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device according to Fig. 3A provided portable data acquisition unit,

Figs. 4A, B, C, detailed circuit diagrams of assemblies D and E.

the device according to FIG. 3A,

Fig. 5 is an illustration of the RAM memories

areas of a memory of the portable data acquisition unit Fig. 3A,

Fig. 6 is a functional diagram of the non-

real-time program in the Read-only memory (ROM) is stored and by means of the central unit of the device according to Fig. 3A is executed,

Fig. 7 the different service pro

grams and their mutual association for coordinating the real-time tasks of the device according to Fig. 3A,

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Figs. 8, 9, 10 the monitoring program of the

and Π

Fig. 6,

Figs. 12 to 17 Details of the MONITORING

SERVICE program according to Fig. 7,

Figs. 18A, B, C The waveforms of different

and D

those anomalies that are within

of the patient's EKG signal, as well as their time allocation, and

Figs. 19A, B and C the segments, the valid R-WeI-

Identify the forms that are generated by means of the MONITORING SERVICE program according to FIGS. 12 to 17 can be recorded.

A heart monitoring device 10 is shown in FIG. 3A, which can be connected to a patient 20 via lines 22a, b and c in order to record signals, which are processed and, in particular, compressed before being stored in a read / write memory (RAM) 26 a portable detection unit 12 can be stored. The heart monitor 10 can be the heart

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of a patient over an extended period of time, for example 3 h and 20 min, while data received in real time are continuously processed and, in particular, compressed in order to store them in a way that enables the subsequent reproduction and display of the data by means of a reproduction unit 30 allowed in a dense form that is easy for the doctor to grasp. The patient's EKG signals are continuously monitored in order to obtain cardiac data in the form of trends of the mean, maximum and minimum heart rate for successive intervals of, for example, 5 minutes, during the data acquisition. The device also stores data in such a form that histograms of the RR interval difference and the heart rate can be displayed. The heart monitoring device is also designed so that certain arrhythmias of interest are detected and, after appropriate detection, a segment of the EKG signal is automatically stored for a limited period of time which is characteristic of the detected arrhythmia. After the acquisition period has expired, the portable acquisition unit 12 is coupled to the display unit 30 in order to initiate a read-out process and a display using an analog chart recorder 36 . The playback unit

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comprises a first part in the form of an adapter 32
and a second part which includes the pen 36 and a sheet margin printer 38. The sheet edge printer 38 has a group of elements by means of which a series of markings along the edge
of the sheet of the pen 36 can be printed
to provide an indication of the occurrence of certain events during the monitoring.
For example, the occurrence of a cardiac abnormality determined by the detection unit 12 is identified by means of a marking that is applied to an output trend curve sheet in order to designate the interval within which the abnormality occurred. In addition, when the patient 20 is experiencing heartache, depresses a highlight button 84
(Figs. 3B and 4A) to cause the cardiac signals occurring during this interval to be identified by means of a marker applied by the sheet edge printer 38. The printer can also provide markings to separate the various graphs as they are being printed out by the pen 36.

In the case of the heart monitoring device 10 according to FIG. 3A the EKG signals that are transmitted via the lines 22a, b and c from electrodes attached to the patient 20

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are taken, fed via a differential amplifier 18 to the portable detection unit 12 and in particular to an A / D converter 16. The signals, which are now in digital form, are sent to a central processing unit (CPU) 14. The input of the A / D converter 16 is connected to the lines 22a and 22b via the differential amplifier 18. The differential amplifier 18 includes an EKG preamplifier that buffers the snap connector EKG leads 22a and 22b to attenuate cable artifacts. The EKG preamplifier drives the differential amplifier 18 with passive grounding. The lead 22b is connected to an EKG electrode provided with gel, which is located approximately at point V5 on the patient, while the lead 22a leads to an EKG electrode provided with gel, which is located approximately on the sternum. These preamp connections will result in a positive R-wave in most patients. The ground line 22c leads to an EKG electrode provided with gel, which is arranged in the left chest area. The patient's heart is monitored externally by means of the arrangement illustrated in FIG. 3A. It goes without saying, however, that within the scope of the invention the measuring electrodes can also be connected directly to the patient's heart. In such a case, the recorded heart signals can be transmitted by means of an implant

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th transmitter is transmitted to an external receiver, which with the data acquisition unit in appropriate Way is coupled. The transmitter and receiver can be constructed in a known manner (US Pat. No. 4,166,470).

A clock signal derived from an interrogation clock generator 24 is fed to the central unit 14 to control the frequency with which the interrogation or sampling signals can be derived from the patient 20. The central unit 14 is in a known manner with its own internal Clock generator 15 equipped to its internal operations as well as the traffic with the other modules of the unit 12 to control. The central unit 14 is via a command / data bus (I / D bus) 27 both with a read-only memory (ROM) 28 as well as with the read / write memory 26 in connection. The read-only memory 28 can store the commands which the central unit 14 executes in order to generate the input ECG signals to capture or recognize in order to process and condense these signals and to process the signals to be stored in predetermined areas of the read / write memory 26. The ones stored in read-only memory 28 Programs are generalized below with reference to FIGS. 6 and 7 and in detail by reference on the FIGS. 8 to 17 explained. The means of the

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Central unit 14 processed and compressed data are stored in predetermined areas of the read / write memory 26 depending on the type of data. The various areas of the RAM 26 in which the data are stored are shown in FIG. shown.

The playback unit 30 is connected to the separation catcher or playback adapter 32 optically coupled. The latter acts as a digital separation buffer that receives information from the acquisition unit 12 that is sent to the analog Sheet writer 36 and the sheet margin printer 38 are to go in order to be reproduced by this. Because the optical separation, the patient 20 can to the detection unit 12 can be connected, while this is connected to the playback unit 30 is connected without the patient's EKG signal being affected by noise or the patient 20 exposed to the risk of electric shock. As shown in Fig. 3A, data passes through a D / A converter 34 to the analog chart recorder 36, at which is, for example, a pen of the Astromed type, model 102, can act. The separation catch storage 32 is also available with the edge printer 38, for example of the Texas Instruments type, EPN 3300, in connection.

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Fig. 5 shows how the different data types in corresponding areas of the read / write memory 26 can be saved. According to FIG. 5, the read / write memory 26 has a first area 26a Recording of EKG data, which are continuously supplied by the device 10 when they are in monitoring mode is located. In the monitoring mode, each QRS complex of the patient's EKG signal is recorded and analyzed to see if it is valid, i.e. not Represents interference signal. When a valid QRS complex signal occurs the signal is processed and stored in the first area 26a. It is desirable to have one Retain strips of the EKG signal in case an arrhythmia is detected that may occur afterwards a desired part of the signal has already been acquired. For this purpose, the first area 26a of the RAM is called Pseudo-band loop operated by storing each queried data group in successively lower RAM addresses until the lower limit of a portion of the area 26a is reached. At this point the Address memory pointer P returned to the topmost memory location of the section concerned; the next Data is written over the old data. The cycle is repeated continuously until an arrhythmia is discovered. A pointer to the boundary between the first and last data is then stored; the white

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External data storage is blocked. After the storage becomes the first / last data pointer or limit value saved at a memory location, which is referred to as the START POINT, in order to move from there to initiate the output of data. The area 26a of the RAM 26 is divided into a plurality of, for example nine, buffer sections 26a-0 to 26a-8, with each buffer section a predetermined number (e.g. 360) comprised of successive storage locations into the Data corresponding to samples of every fourth EKG signal are sequentially entered. When a buffer section is filled, the address or the pointer P is shifted to the area 26a to the top memory location denote the one within the next buffer section is available. In this way, nine strips of the EKG signal can be recorded and stored in RAM 26 in order to obtain and reproduce an optical reproduction of the EKG signal at this point in time. Although only nine buffer sections are illustrated within area 26a of RAM 26, basically forty or even more in the range 26a such sections may be provided. Their number is only determined by the size and cost of the store and by Considerations regarding current draw from the battery limited. It is also possible to have a single

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Provide ring buffer section and the stored there Replicate data in permanent memory locations of RAM 26 when a cardiac abnormality is detected.

A second area 26b is provided in order to store data which is reproduced in a histogram form should be. The area 26b includes, for example two groups of fifty 16-bit cells. A first of the Groups of fifty cells each are used to store an interval difference histogram (IDH), where each cell has four interrogation cycles, i.e. 16 2/3 ms, is wide. After the RR interval has been calculated and the Difference between successive intervals is determined, this difference is divided by four, whereby the fraction is not taken into account. The result of the division process is used to refer to the relevant IDH group cell within the first group of area 26b. The cell in question will incremented to indicate the occurrence of a difference in this particular quantity. According to one embodiment of the invention are twenty-five each IDH cells on the negative or positive side the middle to account for differences that exist between 0 and 100 query cycles, i.e. between 0 and 416 2/3 ms. All differences that are greater

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than 416 2/3 ms, are not taken into account. The second group of fifty cells of area 26b is used to store the rate histogram, each Cell is 5 beats / min wide. After the RR interval measured and the corresponding heart rate is calculated, the relevant rate is divided by five, where the fraction is not taken into account. The result of the division process is used to calculate the to show the rate histogram cell in question. This cell is incremented, causing the occurrence of the concerned Interval is identified. The interval difference histogram is primarily used to indicate rhythm instabilities such as those Atrial flutter, abnormal sinus syndrome, and premature contraction can be caused. That Rate histogram, on the other hand, shows the distribution of the intervals, while the trend curve shows total changes in the Recognize interval.

An area 26c of the RAM 26 forms a storage area for receiving trend data. It includes three groups of forty 8-bit cells. In each cell will be the minimum or the maximum heart rate of the patient or the mean value of the heart rate during the relevant interval, e.g. 5 min, saved. Each group of cells

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speaks a trend interval.

The area 26c is also used to store Data indicating whether the highlight button 84 was pressed or an EKG during a trend interrogation interval was saved. If the patient experiences a symptom, such as dizziness, passed out or notices other impairments that indicate the condition of the heart, he can press the highlight button 84 press provided on the portable detection unit 12 (Figs. 3B and 4B). To Pressing the marking key 84 a special bit pattern is stored in the cell which corresponds to the Trend query interval corresponds to within which the key 84 was pressed. When an EKG strip was saved in area 26c during a certain trend query interval, the bit pattern in of the corresponding cell modified to indicate this fact. When playing back is done using of the analog chart recorder 36 a reference to the interval within which the marking key was pressed, in the form of an identifying time interval Marking so that the doctor can determine the time of pressing the button or saving the ECG query together with the corresponding values

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identify the minimum, maximum and mean heart rate can.

An area 2od is used to store various Variables, which include status displays and flags, which are set during the execution of the process.

The FIGS. 4A, B, C and D show detailed circuit diagrams of the heart monitoring device 10 according to FIG. 3A. The detection unit 12 is essentially shown in FIGS. 4A and 4B. The central unit 14 can be, for example, a CPU module of the Intel 8085A type. In connection with an address catch memory 44, the central unit 14 receives and transmits data via an address bus 46, a control bus 50, a data bus 48 and connectors J1 and J2. Data is received from A / D converter 16 as shown in FIG. 4C; they are transferred to and from the read / write memory 26 via the data bus 48 according to FIG. 4A. The RAM 26 consists of several memory modules, for example of the Harris HM 6514 type. The data bus 48 is connected to the data transport ports DQI-4 of each of these modules. The read-only memory 28 consists of two memory modules, for example of the Intel 2716 type. After addressing, program commands are sent via

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the output ports 00-07 of these modules are read out to be transmitted to the central unit 14 via the data bus 48 to become. As can be seen from FIG. 4A, addresses are assigned to the building blocks of the RAM 26 and ROM 28 fed to one of the building blocks and a selected memory location of the relevant Address block. The central unit 14 creates an initial group of addresses on its outputs AIO, 11 and 12. These addresses go to two Chip or module decoders 40 and 42, which may be decoders of the RCA 4028 type, for example. Address signals are generated at the outputs of the chip decoders 40 and 42, by means of which one of the Chips or the modules of the RAM 26 or the ROM 28 is addressed. The particular storage space to be addressed within one of the modules of the RAM 26 or the ROM 28 is by means of the address latch 44 selected whose input signals come from ports ALE and ADO-7 of central unit 14, in order to generate output signals which are sent to each of the aforementioned modules via the address bus 46 in order to to address a selected memory location there.

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Further command signals come from the port IO / M. she determine whether data should be transferred between RAM 26 or whether data for input / output (I / O) and in particular are to be transferred via the data bus 48 from the A / D converter 16 (corresponding to FIG. 4C), or whether a data transfer to the addressing latch 140 (Fig. 4D) is to be made, which is part of the latch 32 (Fig. 3A). The ports labeled RD and WR ~ determine whether data is in RAM 26 to be written or read from this. As can be seen from Fig. 4A, the central unit 14 has a group of interrupt inputs that are used to simplify the programs, those for carrying out the various processes and functions of recognizing and storing ECG data are needed. For example, goes from that Interrogation clock generator 24 (Fig. 4C) the interrogation signal Via a conductor 80 and the connectors Pl, Jl to the interrupt input RST 7.5 of the central unit 14. The query cycle calls a program QUESTION EKG AB AND MAKE SURE FOR TIMING, which will take samples of the EKG signal and the R-wave of the QRS complex is checked to see if a valid R-wave was determined, and in this way to set an R FLAG, as shown in FIGS.

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12 to 17 is explained in more detail.

Another program interruption occurs when a voltage detector circuit in the form of a Schmitt trigger 54 as part of a power supply 52 (Fig. 4A) determines that the battery voltage is below a predetermined Value has decreased. A battery 82 (FIG. 4C) is connected to the power supply via the connectors Pl and Jl 52 connected. It is designed as an 18 V battery, for example. When the Schmitt trigger 54 detects that the voltage of battery 82 has dropped below 10 volts, an output signal is applied to the TRAP interrupt input the central unit 14 to initiate a controlled transition to a shutdown operation, with only the logical addressing and processing circuitry as well as the chips of the RAM 26 remain energized in order to draw the current from the battery 82 to throttle. The Schmitt trigger 54 has an operational amplifier IJ19, the Output voltage of battery 82, normally 18 V, with the regulated voltage 5SD coming from the output 55 of the power supply 52. If the Battery voltage below a minimum value, for example The operational amplifier U] 9 outputs 10 V, if it drops a high going output through a NOR circuit U8 to the TRAP Interruption condition of the central unit

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14 to thereby initiate the LOW VOLTAGE DETECTOR PROGRAM 604 (Fig. 7).

The circuitry of the sensing unit 12 illustrated in Figure 4A is responsive to such a low voltage condition in the following manner. First, the outputs A15, IO / M and RD of the central processing unit 14 all go high, so that a NAND circuit U5 applies a low-going output signal to a pulse shaper circuit consisting of a capacitor CIo _7, a diode CR5 and a resistor R40. The shaped output signal is fed to a flip-flop circuit 57 , which consists of two NOR circuits U8. According to FIG. 4A, the delayed output signal appearing at the output 56 of the flip-flop circuit 57 is fed via a transistor Q1 to the power supply 52 and to a group of NAND circuits U4 and U5. When transistor Ql becomes energized, a current goes to a switching regulator U20 which causes power supply 52 to de-energize most of the components of device 10. In this manner, the power supply turns off the power to most of the components of the device 10 while the power to the various components of the RAM 26 is maintained. In addition, the group of NAND circuits U4 and U5

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locked in order to prevent further application of address signals from the chip decoders 40 and 42 to the read / write memory 26 . The data previously stored in the modules of the RAM 26 remain stored as a result. After the voltage has been switched off, however, no addresses and / or interference signals that may be generated by the central unit 14 and / or the chip decoders 40 and 42 can reach the read / write memory 26 . By means of the output signal of the flip-flop circuit 57, a transistor Q2 of the power supply 52 is also made live, whereby a positive signal is applied to the input SD of the switching regulator U20, which can be, for example, a regulator of the Silicon General SG1524 type . During normal operation, the controller U20 periodically applies current to the base of a transistor Q3 via outputs C. and C _R in order to charge a capacitor C14 to a nominal voltage of the order of magnitude of +5 volts. The capacitor C14 is repeatedly recharged while it tries to discharge through a coil Ll. This results in an essentially constant, regulated voltage of +5 V at the output, which is designated as + 5SD. In addition, the periodic voltages are transmitted through the primary winding of a transformer T2 to its secondary windings, thus obtaining voltages of + 8V,

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by means of which components of the circuit arrangement according to FIG. 4C are fed. The linear regulator U20 supplies a regulated voltage of + 5V _{at its output V R.} As shown in FIGS. 4A, B, C and D, most of the components of the device 10 are supplied with the regulated voltage + 5SD, which comes from the output 55 of the power supply 52, while this is operating in normal control mode. If, however, the transistor Q2 is made live by the occurrence of a low voltage, an input signal goes to the input SD, whereby the controller U20 is switched to the second, non-operational mode. This disconnects the regulated voltage + 5SD from most of the components of the device 10; the current draw from the battery 82 is significantly reduced. During the shutdown operation, a voltage of + 5V only goes through the output terminal VR of the power supply 52 to the various components of the RAM 26, the chip decoders 40 and 42, the NAND circuits U4, U5 and Uo and the flip-flop circuit 57. The Output signal normally present at terminals C. and C _R of controller U20 goes high, blocking transistor Q3. As a result, the voltage on the primary winding of the transformer T2 and the coil Ll is cut off. The output voltage of + 8V on the secondary side of the transformer T2 and the output signal at the output

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gear 55 are switched off. However, the controller U20 continues to apply the voltage of + 5V via its output Vp to the above-mentioned modules.

The interrupt port RST 6.5 of the central unit 14 is used to determine whether the preamplifier 18 is connected to the portable detection unit 12 (FIG. 3A) via the connector J4. As can be seen from Fig. 4C, the terminals 1 and 2 of the connector J4 are connected to a preamplifier connector P4, in which the terminals 1 and 2 are bridged so that a low level signal or an "O" signal via a Head 94 and the connectors Pl and Jl to the interrupt port RST 6.5 of the central unit 14 is applied. In the absence of a connection to the EKG preamplifier 18, the device 10 is prevented from entering the monitoring or calibration mode.

The Button 84 (Fig. 4C) are pressed to send a signal to the via a conductor 86 and the connectors Pl and Jl Apply the SID input of the central unit 14. In monitoring mode Pressing the key 84 causes a flag to be stored which has a relatively small interval

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identified during the entire monitoring period, within which the patient identified a symptom or felt discomfort. In custody transfer mode, pressing the Key 84 causes the refractory period associated with the detection of the QRS complex to be increased. Of the Connection SOD of the central unit 14 controls the transistor via a conductor 87 and the plug connectors Jl and Pl Ql (Fig. 4C), whereby an EKG light emitting diode 88 is supplied with current. During custody transfer a potentiometer R9 of the EKG amplifier 19 (Fig. 4C) set the gain of the amplifier as a function of the amplitude of the EKG signal of the To bring patients to an appropriate value. The light-emitting diode 88 shows when the potentiometer R9 is set correctly. A start button 96 (Fig. 4C) is pressed to begin operation of the device 10 allow. A signal with a low level is applied to the RESET IN input of the central unit 14. By pressing the start button 96, a low level signal goes through the connectors P1 and Jl to the NAND circuit U5, with the output signal of which the flip-flop 57 is reset. The postponed Flip-flop 57 blocks transistor Q2 by means of a low level signal, causing the high level is switched off at the input SD of the switching regulator U20, so

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that the controller U20 can return to the normally excited state. The central processing unit 14 gives an output reset signal from, by means of which an addressing buffer 140 (Fig. 4D) is reset and cleared.

The computer clock generator 15 (Fig. 4A) supplies a 1843 MHz clock signal, which is the clock for the implementation of the program by means of the central unit 14 as well as for the various other data transfer functions controlled thereby pretends. The functions of the central unit 14 including the various data transfer functions and calculations, are under the influence and in the time frame of the computer clock generator 15 performed while many of the data acquisition functions, including the interrogation of the patient's EKG signals, in real time under the influence of the interrogation clock generator 24 take place.

The incoming EKG signals are shown in FIG. 4C applied to the differential preamplifier 18, which is a conventional Structure has. The output signal of the preamplifier 18 goes to the EKG amplifier 19, which has operational amplifiers 90 and 92, which are connected in series. Using the potentiometer R9, the Gain of the ECG amplifier 19 is set. The end-

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The output signal of the EKG amplifier 19 is fed to the input of the A / D converter Io. The converted digital signal runs from the outputs BO-7 of the A / D converter Ιό via the data bus 48 in order to be selectively stored in the modules of the RAM 26 (FIGS. 4A and 4B) under the influence of the central unit 14.

According to FIGS. 4D and 4E, the separation catch memory 32 and the D / A converter 34 (FIG. 3) are coupled to the analog sheet recorder 36 and the sheet edge printer 38. The separating collecting memory 32 consists of the addressing collecting memory 140, a 16-channel optical separating stage 141 and a DC voltage converter 139. The data to be printed out or displayed go via the data bus 48 to the inputs DO to D7 of the addressing collecting memory 140. The collecting memory 140 is a first group of digital Output signals PBO to PB7, which are fed to the lo-channel optical separation stage 141 (FIG. 4D) and the D / A converter 34 (FIG. 4E), via which the analog chart recorder 36 is controlled. The catch memory 140 supplies a second group of output signals PA1 to PA7, which are sent to the 7th sheet printer 38. The output signals of the latch 140 go to a group of two-channel optical separation stages U4 to Uli (FIG. 4D).

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The isolators U4 to Uli ensure electrical isolation the analog sheet writer 36 and the sheet margin printer 38, which can be fed via a conventional AC voltage mains connection, from the data acquisition unit 12. This ensures that Signals, including the supply voltage, which are received by the writer 36 and the printer 38, do not lead to a distortion of the ECG signals derived from the patient 20. In addition, the patient is 20 secured against electric shocks. The isolated output signals coming from the optical isolators accordingly the outputs PAl to PA7 and PBO to PB7 are connected to the D / A converter 34 resp. fed to a group of driver transistors Ql to Q8. As can be seen in detail in Figure 4E, the collectors are the driver transistors Q1 to Q8 are connected to the inputs of a chart recorder connector 35. In 4E, the margin printer 38 is not illustrated in detail. It is understood, however, that a group of printing elements in the form of heating resistors is built into the analog chart recorder 36. These printing elements are energized to optionally print one or more markings and in this way the various graphs or data representations of the chart recorder 36 to be highlighted. The analog chart recorder

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can in particular be shown in the form of an RR interval histogram similar to Fig. 1, of an interval difference histogram similar to FIG. 2 and provide a trend display which, for a sequence of successive trend query intervals, for example 5 min, which shows minimum / maximum heartbeat rates. When recording the Provides representations by the analog chart recorder 36 the sheet printer 38 makes a series of marks on the same paper to display these different graphical representations to separate from each other. In connection with the trend query curve is also used for a number of different Markings are provided that indicate the occurrence of various events within a trend query. For example, leaves a triple marking a trend query recognize that the system has detected an anomaly. If the patient feels 20 discomfort, possibly related to cardiac activity, and then presses the marking key 84, the sheet margin printer 38 is operated to print adjacent to the relevant To attach a double marker to the trend query. is the ECG signal derived from the patient 20 is excessively superimposed by noise signals, leaving the flat edge printer 38 recognize the occurrence of such noise by placing a single mark over the corresponding Install trend detection. The connector 35 is

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Speaking signals to the resistance heating elements (not shown) to form these marks.

The addressing buffer 140 sends the output signals PBO to PB7 via the optical isolating stages U8 to Uli to the D / A converter 34, which in turn sends an output signal from its output I to an operational amplifier U2. The output signal of the operational amplifier U2 is fed to the signal input of the chart recorder 36, whereby its pen is moved in accordance with the input analog signal. The signal sent to the analog chart recorder 36 can be offset by means of a potentiometer R36.

The operating mode to which the device 10 is set depends on which components of the device are connected the data acquisition unit 12 (Fig. 3A) are connected. For example, the device works either in playback mode or in calibration mode when the playback unit 30 is connected to the portable registration unit 12. According to FIG. 4D, the addressing buffer 140 has outputs PCI and PCO, which are connected to the outputs PC5 and PC4 appearing signals are set to high and low levels, respectively. If, according to FIG. 4C, the Connector P3 is coupled to connector J3,

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The addressing buffer 140 can be accessed in order to determine the signals present at the terminals PCI and PCO and thereby to cause the device 10 to enter either the calibration mode or the playback mode. In addition, input signals from the outputs All and A12 of the central processing unit 14 (FIG. 4A) run to the inputs A1 and AO of the addressing latch 140 in order to determine whether the relevant signal, which is supplied via the data bus 48, is from the outputs PBO to PB7 to the chart recorder 36 or from the outputs PA1 to PA7 to the sheet margin printer 38 is to be applied.

Fig. 6 shows a general flowchart showing how the heart monitor records and compresses cardiac data and reproduces the stored data in a form which provides the physician with intelligible information about the condition of the patient's heart. First, in program step 200, the operator presses the start / reset button 96 on the control panel of the detection unit 12 (FIG. 3B). The program interruptions of the central unit 14 are then blocked in step 202. The central processing unit 14 has a number of interrupt inputs which allow the central processing unit 14 to accept data from various areas of the read-only memory 28. The interruptions

allow hardware mechanization of various Processes to simplify the software and execution time to save. These interruptions in the central unit are initially blocked. The unlock The interruption happens via a series of flags that are in an interrupt register within the central unit 14 are housed and allow selected interruptions of the central unit to be used while the rest are blocked. First, all central processing unit interrupts locked; thereafter unlocks an initialization process selected interruptions of the central unit by Flags can be applied to the corresponding areas of the interruption group. According to another part the initialization go from the central unit 14 Signals which set the separation catch memory 32, so that data can be transferred to and from the analog chart recorder and sheet edge printer 38 and it can be determined whether the reproduction unit 30 is coupled to the detection unit 12. Thereafter the selection program step 204 is carried out, in which one of the following operating modes is selected: Playback mode (PBKM), custody transfer operation (CALIBM) and monitoring operation (MNTRM). In step 204 the system arrangement checked to see which modules are connected to

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the detection unit 12 are connected in order to determine in which operating mode the device 10 can operate. If, for example, the playback unit 30 is connected to the detection unit 12, step 204 transfers the program to the playback mode by means of step 300. If, however, the playback unit 30 is separated from the detection unit 12 and the preamplifier 18 is coupled to the portable detection unit 12 via the connector J4 (FIG. 4C), the device 10 goes over to the monitoring mode 500 via the initialization step. In the connector J4, via which the preamplifier 18 is coupled to the detection unit 12, two connections are bridged, whereby the input RST 6.5 of the central unit is short-circuited or brought to the lowest state, so that in a register of the central unit 14, to which during of the selection step 204 access takes place, an input state is stored. In a similar way, the coupling of the detection unit 12 to the playback unit 30 and in particular the separation interception memory 32 takes place via the input / output port of the central unit 14, which responds when the separation interception memory 32 is connected to the central unit 14.

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Before entering the monitor operation 500, LASSE FLAG CLOSED must be checked, which indicates that the system was calibrated in custody transfer operation 206. If the LASSE FLAG ZU command is not determined, it can System does not go into monitoring mode 500. The MCLEAR program 400 resets the LASSE FLAG ZU, after the process has been transferred to the monitoring operation 500 is to re-enter the monitoring operation 500, unless the calibration operation 206 has been run through again to LASSE To set FLAG TO. In order to enter the calibration operation 206, it must be determined that the data acquisition unit 12 is connected to both the preamplifier 18 and to the separation collecting memory 32 is connected. The former is done by removing the bridged connections in the Connector J4 can be determined. When the data acquisition unit 12 is not coupled to any other module, the device immediately goes into standby mode 208 about.

In calibration mode 206, the CALIBM (calibration controller) program carried out to support the operator in the system on the assumption of different amplitudes of the heart signal and different refractory periods to adjust that become necessary

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to appropriately capture a patient's QRS complexes. A patient's R-wave amplitudes can vary up to 20: 1 within a normal population. Therefore, in order to avoid saturation of the A / D converter 16 and to let the converter work in a range of 30 to 50% of its total capacity, the gain of the input amplifier (Fig. 4C) of the A / D converter 16 must be set, until the normal amplitude of the R wave has such a height that a 2: 1 increase in the EKG signal amplitude can occur without the upper or lower count value limits of the A / D converter 16 being reached. In this mode of operation, the output of the preamplifier 18 is continuously monitored via the A / D converter 16 to determine whether the peak deviation from the baseline, negative or positive, exceeds 40 units or counts of the A / D converter. If the peak input signal is below this limit, the CALIBM program will cause the EKG light emitting diode 88 (Fig. 4C) not to be energized. If the peak amplitudes lead to peak deviations from the baseline which exceed a second limit value corresponding to 60 units of the A / D converter 16, the light-emitting diode 88 is made to light up continuously. The peak deviation from the baseline measured by the A / D converter 16 is between

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40 and 60 units, the LED 88 flashes each time a QRS complex is detected. Typically, the gain of amplifier 90 should be adjusted so that the output of A / D converter 16 deviates from baseline by about +50 counts during the cardiac cycle. For this purpose, the variable gain of the input amplifier 90 of the A / D converter 16 is set via the potentiometer R9 in such a way that the light-emitting diode 88 flashes for each QRS complex. In addition, the refractory period is set in calibration mode 206, ie the expected length of time between the R and T waves of the patient's cardiac signal, during which ECG signals applied to the detection unit 12 are input but not processed to determine QRS complexes. To set the refractory period, the marker button 84 is pressed. As a result, a buzz signal or high-frequency signal is formed in the EKG recording as long as the marking key 84 is pressed. Such a signal is generated by the analog chart recorder 36; its duration increases every 4 seconds while the operator holds down the highlight key 84. The operator holds the highlight button 84 down until the refractory period indicated by the buzz signal extends to the end of the T-wave. The refractory period is dependent on a DIGIT REFRACTORY DURATION ON subroutine

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on the length of the last RR interval and a constant that is only changed during the setting of the refractory period. That is, the corresponding count of the refractory period counter determined in turn the refractory constant, which at Calculate the refractory period after repeated occurrences of the RR interval is used.

After the calibration, indicated by the setting of the LASSE FLAG CLOSED, and the determination that the data acquisition unit 12 is coupled to the preamplifier 18, the selection program step 204 branches off to the delete / initialization program 400. The MCLEAR program is carried out, in which the memory areas according to FIG. 5 are deleted in order to record the refractory constants in preparation for the transition to the monitoring mode 500. The based on FIGS. Monitoring operation 500, detailed in Figures 8, 9, 10 and 11, is controlled by the MNTRM program to detect successive QRS complexes, determine whether or not such complexes are valid, identify valid QRS complexes, assigning RR intervals measure and initiate the processing of the relevant data and the subsequent storage of the processed data in the RAM 26. The RR interval is calculated; the corresponding rate will be

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averages before storage in area 26c of the RAM 26 (Fig. 5) occurs. Then the differences between the successively determined RR intervals calculated to increment one of the bins in area 26b of RAM 26. There is also a classification subroutine provided to detect abnormal or arrhythmic cardiac signals. In particular, it is established whether the rate is above 120 or below 40 bpm (FPM), whether a beat was skipped or whether there is a premature strike. If this is the case, the SAVE FLAG is set and a trigger signal is generated generated to the current group of EKG rhythm signals to be stored in one of the nine buffers in area 26a of the RAM. Shortly after setting the SAVE FLAG will be the data frozen in the running buffer; the pointer for the address of the memory buffer moves to next buffer, if one is available within area 26a.

The supervisory program 500 controls supervisory operational operations; it does not include programs for performing real-time tasks such as timing intervals, R wave detection and calculation of the RR interval. the As is generally shown in FIG. 6, real-time programs are separate to the overall software requirements of the

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System to simplify. Real-time tasks, including the R-wave detection program, are entered once for each cycle of the query clock generator 24. The monitor program 500 is executed as long as a RUN FLAG remains true. Any of the following events can set the LAUF FLAG incorrectly and thus end the monitoring operation: first, the battery voltage for supplying the device 10 can drop below a predetermined level; secondly, the area 26c for receiving the trend data can be filled, ie no further data can be stored there; third, connector J4 of preamplifier 18 can be disconnected. After the RUN FLAG is set incorrectly, the MNTRM program completes final organizational tasks in block 500 and transfers control to program step 208, where the standby controller disconnects all system components with the exception of RAM 26 . After completion of each of the steps in the programs 300, 20ό or 500, the process goes to the standby mode 208, where the interruptions of the central processing unit 14 are blocked and the data stored in the RAM 26 are protected from being read out or overwritten. Furthermore, the power supply 22 is used for all parts of the device 10 with the exception of the power supply for the read / write memory 26

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switched off, which ensures that the there stored data remain securely stored. This is how the power is drawn from the battery 82 minimized; maximum battery life is ensured.

Selecting step 204 can cause the process to go immediately to standby 208 if the ports of the preamplifier 18 and the reproduction unit 30 are separated from the detection unit 12.

As can also be seen generally from FIG. 6 , a real-time interface program 600 is provided which organizes the various tasks that must be carried out in real time as a service for the operating mode controller programs that can be executed in computer time, for example the acquisition of the R waves. These real-time service programs can detect various conditions by which the device 10 is immediately brought into standby mode 208.

The real-time interface program 600 is detailed in FIG shown. In step 602 it is determined whether the output voltage of the battery 82 is low. If this is the case, the central unit 14 is caused to

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to enter a LOW VOLTAGE DETECTOR PROGRAM 604, putting the process on standby 208 is transferred. As can be seen from FIG. 4A, the output voltage of the battery 82 is set by means of the Schmit * t trigger 54 detected. If it is determined that the output voltage of the battery is a predetermined value, for example If it falls below 10 V, the Schmitt trigger 54 applies a high-level or +5 V signal to the TRAP input the central processing unit 14, causing it to proceed to the LOW VOLTAGE DETECTOR PROGRAM 604. Within the program 604 it is first determined whether the process is in the monitoring mode 500 is located. If this is the case, the LAUF FLAG is set incorrectly. As explained in more detail with reference to FIG is, it is ensured in monitoring operation 500 if the LAUF FLAG is set incorrectly that the EKG data is complete that the calculation of the current RR interval is completed and that the mean value of the RR interval then obtained is calculated and is stored at the relevant memory location in RAM 26. After that the read / write memory 26 is switched off in such a way that no stored data is lost and its power supply is maintained remain. The Schmitt trigger 54 controls the TRAP interruption of the central unit 14 to

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a program interrupt in standby mode 208 to effect and in this way to reduce the otherwise necessary programming. In step 606 found that the EKG preamplifier 18 is missing, in particular that the one assigned to the preamplifier 18 Connector J4 is disconnected, i.e. the bridged connections on the RST 6.5 break the central unit 14 is missing. The RST 6.5 break goes to +5 V, whereby the central unit 14 is a PREAMPLIFIER STATUS PROGRAM 608 initiates, within which the process transfers to standby mode 208 can be. When the system is in supervisory mode 500, program 608 forces the system to to run through a program loop until the preamplifier 18 is reconnected to the detection unit 12 or the highlight key 84 is pressed. If the highlight key 84 is pressed, the RUN FLAG is set incorrectly, causing the MNTRM program to put the system in standby 208 mode. While that System runs through the loop, no further data is stored or processed within the RAM 26, to identify QRS complexes. When you press the Marking key 84 the mean value of the RR signals received up to this point in time is also calculated, and those in various other memory locations of the RAM 26

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stored pointers are reset. If the process is in calibration mode 206, the system immediately goes to standby mode 208 if
it is found that the EKG preamplifier 18 is not
connected.

Although in the illustrated specific embodiment
only a single highlight key 84 is illustrated,
there may be a group of such buttons. In such a case, the patient can specify the type of sensation of a particular symptom, body function, or activity. In addition, instead of the marking button 84, an accelerometer attached to the patient's body can be provided, which accelerates a rapid body movement of the patient, which is characteristic of high physical activity
Switch closes so that the patient's EKG signal
is recorded for a predetermined period of time.

According to FIGS. 4A and C are the query clock generator 24 to the interrupt input RST 7.5 of the
Central unit 14 a 240 Hz interrogation clock signal. The polling clock generator causes the central processing unit 14 to execute a QUARTZ CLOCK PROGRAM 612 which, as shown in FIG. 7, provides the appropriate mode service routine

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is set. The program 612 checks the current operating mode, i.e. it determines which of the operating modes 300, 206 or 500 is performed. Depending on the current operating mode, one of the service programs 614, 616, 618, 620 or 622 selected for execution. The program checks XCMODE, an operating mode status variable, allocated to a specific location within RAM 26 to determine if their value is equal to 0, 1, 2, 3 or 4, which corresponds to the service program 614, 61ό, 618, 620 or 622 to be selected. The service programs 614, 616, 618, 620 and 622 are executed in real time and act as an interface between the input signals received in real time and the other operations and calculations that using the corresponding operating mode controller in the computer time under the control of the clock generator 15 connected to the central unit 14.

The CALIBRATION PROGRAM 614 takes care of the basic time control of the system in real time for the calibration controller (CALIBM) 206 is necessary. The program 614 repeatedly calls the R-wave detection subroutine in response to the polling clock generator which detects the QRS complex of the EKG signal and determines its amplitude. The resulting ECG peak signals are saved and

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supplied to the calibration controller (CALIBM) 206, which is dependent on from the computer clock generator 15 determines whether the QRS complex amplitudes are acceptable. The CALIBRATION PROGRAM 614 also allows the EKG signal and the buzz signal if necessary go to the analog chart recorder 36 to enable the setting of the refractory period explained above.

The MONITORING PROGRAM 616 acts as a real-time interface for the monitoring operation 500, the implementation of basic time control functions, the retrieval of the R-wave acquisition program and the storage of each fourth ECG bytes, i.e. the corresponding amplitude, in one of the nine rotating buffers provided in area 26a of RAM 26. If during monitoring operation 500 a flag is set by MNTRM, which indicates the detection of an arrhythmic signal, the current buffer of area 26a is saved; the MONITORING PROGRAM 616 provides a pointer for the next buffer in area 26a, if one is available.

The DATA SHEET PROGRAM 618 effects the time control for the various data records, taking data from output to RAM 26 at a rate that corresponds to the step-by-step forward movement of the

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corresponds to the same sheet of paper. For example, each Cell of the trend data, which is indicative of the mean minimum and maximum RR intervals Ie, with the Sheet writer 36 connected at such a speed that one cell per mm of feed of the paper sheet is reproduced. The paper sheet is advanced 1 mm every 40 ms. In order for such timing to ensure, the program 618 generates a driver clock for the output signal of the interrogation clock generator 24 the recorder 36. The interrogation cycle cannot simply be divided down to get the desired 40 ms drive signal. Rather, it is a timing subroutine provided that on 10, 10, 9, 10, 9 clock signals with the provision of corresponding driver feed signals for the writer 36 responds. The corresponding 48 clock signals, which occur within a period of 200 ms are exactly equivalent to the occurrence of five 40 ms intervals. The fact that with every driver feed signal a minor error affects the overall accuracy of the recorder 36 did not produce a record.

The DATA SHEET PROGRAM 618 runs in real time to reproduce the trend and Histogram data by means of the analog chart recorder 36

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and the sheet margin printer 38. Also will in the context of program 618 the analog chart recorder 3ό a 60 Hz square wave signal is supplied to get markings between the recordings made by the recorder 36 can be reproduced. For example, there is a marked interval between the trend recording and the Histogram recording provided in order to show the doctor a clear separation between the two.

The PLAYBACK PROGRAMS FOR POSITIVE SLOPE and NEGATIVE SLOPE 620 and 622 speak to positive and negative, respectively Slopes of the input ECG signal to interpolate between ECG points and series of straight lines between two adjacent points, so that by means of the chart recorder 36 a smooth-looking Curve is generated. A sequence of 16.67 ms long straight line segments is used to move between the reproduce an essentially smooth curve at both points. Taking into account that the data acquisition unit 12 is a portable unit and has a read / write memory 26 of limited storage capacity it is desirable to store less than each sample of the patient's EKG signals in order to to extend the length of time for which the monitoring device 10 can be used. In the course of the re-

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in which the data stored in RAM 26 would exist be read out, but must be interpolated between the points recorded in RAM 26 in order for a smooth appearing curve to worry.

The monitoring operation 500 shown generally in FIG. 6 is shown in detail in FIG 204 transfers control to MNTRM 502, the entry point 1, via the MCLEAR program 400 for the supervisory controller 500. Control then passes to step 504 for a warm-up delay and to store selected variables within the area 26d of the RAM 26. For example must be the pointer to designate an initial buffer location in area 26a, in trend query area 26c and in Histogram area 26b can be set. Furthermore, all storage locations are in the minimum rate part of the trend data area 26c is set to a maximum value to simplify the programming steps necessary to then determine the minimum heart rate. In addition, a variable is stored for counting the polling rate to determine every fourth EKG poll, so that a selected number can be counted down by means of interrogation cycles that appear one after the other and after counting down to zero the relevant ECG

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31Q180Q

Query in the designated space of the range 26a is stored. The variable XCMODE in RAM 26 is set to "1" to indicate to block 612 that the system is in monitoring mode. The MONITORING PROGRAM 616 is initiated, the monitoring controller with appropriate real-time services, such as timing and QRS recording, for each positive To supply transition of the query cycle. In determining the length of the trend interval in terms of a chosen one Number of interrogation pulse signals counting value is counted down when each interrogation pulse occurs, For example, to determine a 5 min-Interval1 with the count value "0". There is also a lockout period stored that for a time delay ensures before a flag can be set by means of MNTRM that the permanent storage of data within a buffer of area 26a.

After these and other variables have been stored, the process continues via loop entry point 506 to decision step 508 which determines whether the RUN FLAG has been set true or false. The LAUF FLAG is set incorrectly if the battery voltage turns out to be proves low, the connector J4 of the EKG amplifier 18 is disconnected, the trend memory area 26c or

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the histogram storage area 26b is filled or the pointer designating the buffer within the area 26a indicates that all buffers are already full. If the LAUF FLAG is set incorrectly, the program opens Go to step 520, where the data in the current trend query or interval is calculated based on the previous received RR intervals to obtain an average value. After that, the process goes to the standby program 208 where commands are given to the power supply to de-energize all components of the system with the exception of the RAM 26 and the associated chip selection logic, so that the storage of the previously recorded Data continues when the battery is running low.

On the other hand, if the RUN FLAG is set true in step 508, i.e. the system is operational to receive EKG signals to receive, process and store, the process proceeds to step 510 where controls whether the highlight key 84 has been pressed. If the highlight key is pressed, during the step 512 an event marker in a Hi If memory group stored in RAM 26 to identify the query or interval in which the highlight key 84 was pressed. After step 512 or when decision block 510 indicates that the marker

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if it has not been printed, the process goes to step 514 about. It is determined whether the R FLAG has been set true, by the R-wave detection part of the MONITORING SERVICE PROGRAM is carried out, as is explained with reference to FIG. If so, there is a transition to the program 700, as explained in detail with reference to FIG. In program 700, the MONITORING PROGRAM 616 (FIG. 7) and, in particular, the R-wave detection program called up thereby Data used to reset the R FLAG, the R-WAVE TYPE data indicative of its existence of interfering noise and are stored in the relevant area of the RAM 26, to be processed and to that stored in one of the buffers of RAM 26 The RR interval. After the program 700 is executed or decision step 514 has shown that the R FLAG is set incorrectly, the process continues to step 518 where the ELAPSED TIME is within a trend query interval TSI with the value END OF TSI is compared, which is stored in area 26d to determine whether the trend interrogation interval has passed i.e., whether 5 minutes have passed. The ELAPSED TIME value is stored in a counter, the is formed in the area 26d of the RAM 26; it is incremented when the polling cycle occurs. If the inter-

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3101BOQ

vall is over, i.e. step 518 for the answer yes leads, in a program 800 explained with reference to FIG. 9, those in the completed trend interrogation interval stored data summarized to the mean RR interval and thus the mean heartbeat rate to determine. Thereafter, the RR-1 interval data becomes the next memory location in area 26b. If decision step 518 indicates that the trend polling interval has not yet expired, or when program 800 is complete, the process goes to Step 516 about where the process is halted until the next polling clock occurs and execution of the MONITORING PROGRAM causing the next patient derived ECG data to be entered and processed. The program loop is then completed by returning to marker 506 to review and process the next EKG data.

As shown in FIG. 9, program 800 is entered via tag 804 to initiate the consolidation process. In step 806 the sum of the RR intervals within a single trend query interval (TSI) corresponding to the storage in a memory location of the area 26d by means of a count value

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divided, which shows the number of RR intervals, collected during a single trend polling interval. Then the middle interval is inverted, to get the average rate of the patient's heartbeat during the trend query interval. as next, in step 808, the TSI PTR pointer is incremented by "1", thereby causing the RR interval data for the next trend query interval in the next cell or bin of the area 26c. Thereafter, in step 810 the current pointer TSI PTR is compared with an indication of the maximum capacity of the area 26c. -If he is greater than the maximum capacity, the RUN FLAG is set false in step 812, which, as above As explained with reference to FIG. 8, step 508 the process via step 520 to the standby program 208 transferred. If step 810 shows that im Area 26c further memory space is available, or if the RUN FLAG is set incorrectly in step 812 has been, in step 814 the counters formed in the area 26d of the RAM 26 are cleared and used to count the number of intervals as well as those occurring during the new current trend query interval Sum up intervals. Thereafter, in step 816 the end time indicator of the current trend query inter-

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valls END OF TSI deferred to the next end of the trend query interval by the current Added value of ELAPSED TIME counter 300 s will. The process then returns to the monitoring routine MNTRM (FIG. 8) in step 818.

The type of processing and storage of the RR data according to the program 700 (FIG. 8) is shown in detail in FIG.

The program is entered via the marker 704 in order to process and store the data related to the RR interval belonging to the QRS complex, which last means of the MONITORING PROGRAM 616 was determined. In block 706, the R FLAG is set false to denote the detection of a QRS complex must be confirmed by the MONITORING PROGRAM 616. Block 706 also receives the Variable R-WAVE TYPE, which indicates whether the QRS complex is detected is disturbed by noise, and an RR INTERVAL, which is indicative of the measured RR interval. as next, the value of RR-INTERVAL is placed in the NEW RR storage location of area 26d. Afterward the value of COMBO RR is set equal to the sum of CURRENT RR plus NEW RR, which results in the last two recorded Values of the RR intervals are summed up.

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The NEW RR values corresponding to the most recently calculated RR interval and COMBO RR are used to determine whether a group of patient EKG signals corresponding to the detection of an anomaly can be saved. The R-wave data must be classified so that the intervals associated with valid R-wave signals processed while noisy signals are not taken into account. In addition, intervals that one Follow premature beats are treated in a different way than intervals that are in a regular rhythm appear. According to FIG. IC, the variable R-WELLENTYP is evaluated in step. The in connection Change in the value of R-WAVE TYPE provided at block 708 provides for the classification of any sensed QRS complex. For example, assume that the QRS complexes are not disturbed by noise and the device has just been turned on. Then, R-WAVE TYPE is set to "4". If consequently the very first QRS complex is detected, block 708 passes the Control to step 728. This does not make use of any RR interval information because this information is meaningless if no previous interval was determined. Because that's assigned to the next QRS complex Interval has meaning, step 728 sets the R-WAVE TYPE to "3". Consequently will

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the next undisturbed complex is processed in step 724 where the detection of the first undisturbed QRS complex is used to initialize the system for the storage of the subsequent undisturbed signals. In step 724 the serial storage locations for the most recent values of the RR interval, viz NEW RR, CURRENT RR, PREVIOUS RR, and PREVIOUS RR shifted by the most recent value of the RR interval to be introduced into the memory location NEW RR of the RAM. Then the program PLACE REFRACTORY DURATION EIN called to calculate the refractory period as a function of the set the last recorded interval between QRS complexes. The R-WAVE TYPE is then set to "2" in order to process the next QRS complex at which is a normal, undisturbed QRS signal. After performing step 724, the program returns 700 back to step 518 of the monitoring program 500 via step 726.

After recording the next QRS complex, recognizable made by setting the R FLAG signal, the process returns to subroutine 700. Because the signal R-WAVE TYPE is set to "2", step 708 advances the program to step 722 where an acceptable QRS complex as a regular rhythm or

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is stored as an early signal. The SET REFRACTORY DURATION subroutine is executed to set the refractory duration as a function of the RR InteRvalIs. The UPDATE DELTA subroutine is then called to calculate the difference between successive RR intervals in the delta or difference histogram and to store it in area 26b of the RAM. The CLASSIFY AND SAVE subroutine (FIG. 11) is then executed to determine whether the detected undisturbed QRS complex is part of a regular rhythm or represents a premature beat. If it is part of a regular rhythm, the R-WAVE TYPE signal is left at "2". If the QRS complex occurs early or prematurely, the value R-WAVE TYPE is set equal to "1". The regular rhythm and premature beats are processed and stored accordingly, as described in connection with FIG. The various memory locations for recording and storing the RR intervals are then updated with the most recent value of the RR interval, which is stored in the NEW RR memory location. After the conclusion of step 722, the subroutine 700 is exited via step 726 in order to arrive at step 518 of the monitoring program 500.

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When acquiring the next QRS complex after setting of the R-WAVENTYP signal equal to "1", step 708 transfers control after it has determined the "1" status to step 720 where the QRS complex that was preceded by a premature beat is processed. A Such an impact to be designated as a compensation impact is not stored in the trend area 26c of the RAM 26. However, the difference between successive RR intervals is calculated and the program UPDATE DELTA is called to store the calculated difference in the IDH group of RAM area 26b. In addition, the subroutine SET REFRACTORY DURATION is used to set the refractory period as a function of the last calculated QRS interval is set. Then the signal R-WELLENTYP is set equal to "2", to enable the ACCEPTABLE program to take up the subsequent normal QRS complex. In addition, the areas of the RAM 26 for receiving the previously calculated and stored values of the RR interval with the most recent value of the RR interval updated, which is located in the NEW RR memory location.

If it is determined in the MONITORING SERVICE program 616 that the signal is noisy, the program 6] 6 sets the R-WAVE TYPE to "0", whereby the step 708 the

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Passes control to step 718. In step 718 the newly measured RR interval is not stored, because it is disturbed. The R-WAVE TYPE, however, is set to "2" in order to initialize the next, undisturbed Allow QRS complex.

The ACCEPTABLE program 722, shown generally in FIG. 10, for processing the patient's EKG signal and for Storing data that has been shown to be a valid and acceptable R-wave is detailed below Explained with reference to FIG. 11. The ACCEPTABLE program 722 begins with step 730 where the subroutine SET REFRACTORY DURATION is called to set the R. refractory period, whereupon the device 10 is prevented from further cardiac activity or to the Capture incoming lines for this period after the occurrence of the R-wave. In one patient with a heart rate of 75 beats / min (BPM), the refractory period is typically on the order of magnitude from 300 to 400 ms. The refractory period is determined using the SET REFRACTORY DURATION subroutine in a variable manner as a function of the previously determined RR interval which is stored in the memory location NEW RR in a rotating buffer of the area 26d of the RAM 26 is. This rotating buffer comprises four

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Storage locations in which the four last determined Values of the RR interval are stored in the order NEW RR, CURRENT RR, PREVIOUS RR and PREVIOUS RR will. When a new value of the RR interval is calculated in the manner explained with reference to FIG or is selected, it will first be stored in the NEW RR storage location of the relevant rotating In the buffer while the old values of the RR intervals are transferred to the next memory locations will. The sub-program SET REFRACTORY DURATION selects the value of the NEW in the memory location RR located RR interval and determined with the help of the expression REFRAKTÄRDAUER = KQT (NEW RR + 27) / 60 the length of the refractory period in terms of sample clock counts of the clock generator 24. Then in step 730 called the UPDATE DELTA subroutine to determine the difference between adjacent RR intervals by subtracting the value stored in the PREVIOUS RR memory location from the value that is stored in the memory location CURRENT RR. The calculated value of the difference between adjacent RR intervals is used to create a pointer a bin or cell within the interval difference histogram group of the area 26b of the RAM 26 to be determined. The relevant bin is then incremented by "1", the occurrence of the relevant difference

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between the CURRENT RR and PREVIOUS RR intervals to count.

Decision block 732 is executed to determine whether a premature strike has occurred. This determination is based on those characteristic of the RR intervals most recent data stored in the memory locations NEW RR, RUNNING RR, PREVIOUS RR and PREVIOUS RR des rotating buffer are stored. Two types of premature strikes are identified, and a premature beat with a compensating pause and an interpolated beat. Capturing this Stroke types occurs because they malfunction the ventricles can be assigned and are to be addressed as more serious than premature blows that indicate malfunctions of the atria. The occurrence of a premature strike with a compensating pause is shown in Fig. 18A. There is a series of R waves RO, RI, R2, R3 and R4 shown, the R wave being RO in time appears first and the R-wave R4 appears last in time. As illustrated, the R wave R3 is early occurred; it is to the right in Fig. 18A moved to the R-wave R2. Also, the distance between the R waves R3 and R4 is greater than normal, which provides a compensating pause, so that the R-WeI-

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le R4 approximates what is normally expected Time occurs. An intermediate premature strike is shown in Figure 18C. It is located a beat with the R-wave R3 is approximately in the middle between the strokes that make the R-waves R4 and R2 correspond. The interval between the R-waves R4 and R2 is approximately the same as normal occurring RR interval. The subroutine 732 determines whether a premature strike is compensating Pause or an intervening premature strike has occurred. Those concerning the premature strike Data is processed and stored in a first manner during steps 736 through 742 then, if no premature strike has occurred, the RR interval in steps 748 through 764 to a second Way is processed.

The determination of whether the strike is premature or not is done in the following manner by examining the values stored in the memory locations NEW RR, CURRENT RR, PREVIOUS RR and PREVIOUS RR of the rotating buffer. The subroutine 732 determines whether a first condition is met, that is, whether the RR interval stored in the interval memory location CURRENT RR is less than 75 % of the value that is stored in the memory.

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PREVIOUS RR is stored. This comparison is indicated in FIG. 18B, where the interval between the R-waves R2 and R3 is less than 75 % of the interval between the R-waves R1 and R2. To determine the existence of a compensating pause, the value COMBO RR, which is indicative of the sum of the RR intervals stored in the storage locations NEW RR and CURRENT RR, is compared with a value that is indicative of 175 % of the RR interval, that is stored in the PREVIOUS RR memory location. As shown in Fig. 18B, the length between the R-waves R4 and R2 is compared with the length between the R-waves R1 and R2. If the length between R-waves R4 and R2 is greater than 1.75 times the length between R-waves R1 and R2, and if the first condition is met, decision block 732 provides an indication that the strike is a premature strike with compensating pause by passing control to step 736.

Second and third tests are done to determine whether there is an intermediate premature blow R3 according to FIG. 18C. It is determined whether the value COMBO RR, which is indicative of the sum

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310180D

of the values in the memory locations NEW RR and RUNNING RR is less than 1.25 times the value of the RR interval stored in the PREVIOUS RR memory location is. At this time, as shown in Fig. 18D, the total time becomes between the R-waves R2 and R4 compared with the time between the R-waves R1 and R2. A The third test is carried out to determine whether the value stored in the COMBO RR memory location is less than 1.25 times the value of the RR interval is that in the PREVIOUS memory location RR is stored. In other words, the length between the R-waves R2 and R4 becomes with the length between the R-waves RO and Rl compared to get an indication of the stability of the heartbeat distribution. If the heartbeat distribution is very irregular, the detected beat may not be a premature one Blow, but a sign of another, more dangerous anomaly. If the first condition and the Results of the second and third tests are positive, decision stage 732 provides an indication that that an intermediate premature blow was detected; the process continues to step 736.

Step 730 (FIG. 11) marks the beginning of a program for premature strike processing. Step 736 sets the R-WAVE TYPE flag equal to "1",

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whereby the processed R-wave is noted as an anomaly will. As a result, when the program STORE RR INTERVAL DATA of FIG. 10 is run through again, a branch is made to the subroutine 720 PROCESS ANOMALY, as a result of which only the RR interval data is stored and prepare the system to receive the next R-wave as an acceptable R-wave. Next, in step 738, the memory location PB HISTORY in area 26d of RAM 26 is looked up, where the number of premature beats is counted and recorded for the current trend polling interval determine whether there is still room for further incrementing. If there is still space available, will the memory location PB HISTORY is incremented by one in step 740. In either case, step 742 occurs where the WAVEFORM STORAGE MANAGER program is called, passed to the MONITORING SERVICE program to initiate processes that are premature Rescue waveform query containing beat in one of the circulating buffers of area 26a of RAM 26. In addition to initiating waveform storage WAVEFORM MEMORY MANAGER a memory lock is performed in step 742, which prevents the waveform memory area 26a of the RAM in a few minutes by a "run" of premature hits or others

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Arrhythmias is filled. When the subroutine SHAFT SHAPE MEMORY MANAGER is called to store a waveform, it compares the current value of TIME ELAPSED with the type of arrhythmias saved. If the blocking period has not expired is, the WAVEFORM MEMORY MANAGER subroutine simply returns without initiating a query rescue. When the lockout has expired, a query rescue is triggered and the lockout period is initiated, to prevent storage of other similar arrhythmias for 10 minutes by adding to the current one Time taken from ELAPSED TIME should be added to 600 s to determine the time at which the Storage of a query for this particular arrhythmia waveform is allowed. Thereafter, in step 744, the storage locations of the rotating buffer are advanced, whereby the RR intervals stored in the various specified memory locations are transferred to the next later Storage space while the last calculated value of the RR interval is stored in the storage space NEW RR arrived.

If in decision step 732 it is determined that the field or R-wave being examined is not is premature, proceeding to step 748 which

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represents the start of a program by means of which non-premature beats are processed. Step 748 calculates the current heart rate by inverting the value of the RR interval stored in the CURRENT RR memory location. In addition, the cells within the current bin of the trend query area 26c are updated with regard to the maximum / minimum rate trends. The memory locations in which the maximum / minimum rate trends are stored are compared with the current calculated value of the heart rate. If larger or smaller, the corresponding bin storage space is updated with the new maximum or minimum rate. The determination of the maximum and minimum rates of the heartbeat provides statistical information regarding the regularity of the heartbeat; it is reproduced for the information of the doctor. It is also possible to use the differences between successive intervals of the peak cardiac activity signal or heartbeat, which are calculated for the purpose of forming the interval difference histogram, in order to calculate the standard deviation of the interval differences. Such a standard deviation can be determined for each trend interrogation interval and stored in a suitable memory location corresponding to this interval. Then in the

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In step 750, a part of the last selected or calculated value of the RR interval, which is stored in the storage location CURRENT RR, is added to the value of the storage location RR SUM in the area 26d of the RAM 26 . Instead of using the total value , part of the RR interval is used to reduce the storage space required for the storage space RR SUM . At the end of a certain trend interrogation interval , the subroutine TSI TOTALIZING is called to calculate the mean RR interval by dividing the sum of the RR intervals stored in the memory location RR SUM by the number of interrogations recorded .

Next, according to FIG. 11, it is determined whether an abnormality other than a premature beat occurs, in particular whether a tachycardia, a bradycardia or a skipped beat is present, in order to set a series of flags, whereby the special interrogation of the EKG signal, which corresponds to the abnormality is stored in one of the rotating buffers of the area 26a of the RAM 26. First, in step 752, the most recently calculated value of the heartbeat rate is compared with that maximum rate, the exceeding of which is an indication that an abnormality called tachycardia is in the patient's heart

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31018OQ

is present. Further, in step 752, it is determined whether the rate increases by changing the values of the RR intervals stored in the storage locations CURRENT RR and NEW RR be compared. If the value stored in the NEW RR memory location is equal to or greater than the is the value stored in the storage location CURRENT RR, indicating that the rate has begun to decrease, a transition is made to step 754. There it is WAVEFORM MEMORY MANAGER subroutine called in order to set the flags that enable a number of ECG queries that are indicative of tachycardia, is placed in a rotating buffer of the area 26a of the RAM 26. For example, the selected maximum rate set to 120 beats / min. When the last value of the heart rate is not above this maximum value the subroutine proceeds to step 758 where the most recently calculated rate is compared to a minimum rate which is indicative of bradycardia. Is below the last calculated rate the minimum value of, for example, 40 beats / min, in step 760 the subroutine WAVE SHAPE MEMORY MANAGER in order to set the flags by means of which a sequence of EKG data representing the bradycardia in is stored in a rotating buffer of the RAM memory area 26a. Is the last calculated rate

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not below the minimum value, a transition is made to step 762 where it is determined whether a beat has been skipped. The value of the RR interval stored in the storage location CURRENT RR is compared with 1.75 times the value of the RR interval stored in the storage location PREVIOUS RR. If the value is greater, there is an indication that a beat was skipped. There is then a transition to step 764 in order to call the program WELLENFORMSPEI-CHERMANAGER and to set flags which cause a corresponding sequence of EKG inquiries to be stored in one of the rotating buffers in area 26a of RAM 26. After each of steps 754, 760, and 764, the relevant rate histogram cell is incremented in step 756. Step 744 updates the values of the RR intervals in the storage locations de? rotating buffer before returning to the MNTRM program, specifically to step 518 (FIG. 8).

The program 616 MONITORING SERVICE shown generally in FIG. 7 will be explained in more detail with reference to FIG. Because of the determination of the interrogation clock signals that the When the central unit 14 is approached, the program QUESTION EKG AB AND CARE FOR TIME CONTROL is first called up. As

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-9G-

Described in more detail with reference to FIG. 13, a sample (query) of the EKG signal is recorded and prior to storage processed. Four such queries are stored and then averaged before being put into a memory location ECG BYTE can be introduced. The program 800 also determines whether there is an R-wave. If so is, the R FLAG is set true. Further, it is determined whether or not the R wave is disturbed by noise not. If the R-wave is noisy, the R-WEL-LENTYP is set equal to "0". That shown generally in FIG Program 800 QUESTION ECG AB AND CARE FOR TIME CONTROL is shown below with reference to FIGS. 13 to 17 explained in more detail. In step 802 it is determined whether the fourth EKG interrogation was made by the CLOCK GENERATOR COUNT is checked. If it is equal to "0", the corresponding ECG query is the fourth query. aside from that it is determined in step 802 whether space is available stands to store the next EKG query in one of the nine rotating buffers in the area 2 <5a of the RAM 26. If it is the fourth query and space is available, you will go to step 804; otherwise the process returns via exit 802 to the main program. In step 804 the mean value display of the last four samples is stored in a memory location of one of the rotating buffers.

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which is identified by the pointer LOOP PTR will. Then the LOOP PTR value is incremented, to choose the next storage location in the rotating buffer. It is then determined in step 806 whether the SAVE EKG FLAG by the WAVEFORM MEMORY MANAGER subroutine due to one of the steps 742, 754, 760, or 764 was set to be an abnormality, such as a tachycardia, or a bradycardia a skipped beat. If the RETTE EKG FLAG is set to true, a transition occurs to step 808 where the LOOP REMAINING counter is decremented so that a predetermined number of for example 60, additional interrogation of the EKG signal can be stored in the rotating buffer after the anomaly is detected. All in all there are 360 EKG inquiries in one of the rotating buffers of area 26a of RAM 26. Is in step 806 made the decision NO, the subroutine 616 returns to the main routine.

In step 810 it is determined whether the rotating buffer has been filled with the ECG data, the execution of the further steps being delayed until the 60th Queries of the patient's ECG signal that occur after the SAVE ECG FLAG has been set true

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according to the decision made in step 810 are. After the buffer has been filled, the process proceeds to step 812, where the start / end pointer is in the filled rotating buffer is stored to allow access if the stored in this buffer Data are to be read out. Also, in step 812, the memory pointer is set to the first memory location of the next available rotating buffer in area 26a of RAM 26 is set. In step 814 occurs a decision as to whether another rotating buffer is available in area 26a. If not, it will be RUN FLAG set incorrectly, which instructs the MNTRM program 500 to transfer control to the standby program 208 to transfer. If in step 814 there is another rotating buffer available, in step 816 the memory location REMAINING LOOP with the predetermined count of the additional ECG samples, for example 60, to be saved after the anomaly is detected. After that, will the SAVE EKG FLAG set incorrectly in order to end the saving of the EKG inquiries in one of the rotating buffers. Afterward there is a return via the exit point 820 in order to carry out the step of the monitoring program 500, which was interrupted by the polling cycle.

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As shown above with reference to FIG. 7, the program MONITORING SERVICE called upon occurrence of each of the polling cycles, if the device 10 accordingly 3 operates in the monitoring mode, i.e. if the preamplifier 18 is coupled to the data acquisition unit 12 is. In the program 800 QUESTION ECG AND CARE FOR TIME CONTROL, the ECG signal is queried accordingly made the polling cycle, which occurs with a repetition frequency of 240 Hz; it is determined whether a valid R-wave is present, as is shown subsequently with reference to FIGS. 13 to 17 is explained in more detail.

13, the subroutine 800 begins with a time control step 822, in which the EKG light-emitting diode 88 (FIG. 4C) for a fixed predetermined period of time, for example 40 ms corresponding to 24 counting steps of the interrogation clock generator, depending on the detection of each R-wave Electricity is applied. 24 count values are loaded into a RAM memory location LIGHTING DIODE TIMER and counted down until the count value "0" is reached. A command is then issued to turn off the light emitting diode 88. In addition, in step 822, two counters in area 26d of RAM 26 are incremented, which are used to time control two separate functions. On the one hand, the ELAPSED TIME storage space is incremented every second

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incremented and used as a system timer that is started at the beginning of the monitoring or calibration operation. The variable ELAPSED TIME is used for timing the trend interrogation and also timing the blocking period within which no further sequences of ECG signals can be stored, as explained above with the aid of program 742 WAVE SHAPE MEMORY MANAGER of FIG. The second clock generator is formed by the memory location RR-TIMER and used to determine the duration of the RR interval, ie the interval between successive, valid R waves. The starting and stopping of the storage location RR-ZEITGLIED are described below. Then, in step 824, an INPUT AND FILTER ECG program is retrieved whereby an interrogation ECG signal is recorded and stored in a four-memory rotating buffer that is incremented each time a new ECG interrogation is recorded. After a query has been recorded, the EKG data are filtered by averaging the contents of the buffer comprising four memory locations and storing the result in the EKG BYTE memory location. After the next query has occurred, the averaged ECG data, which are stored in the EKG BYTE memory location, are transferred to the PREVIOUS EKG BYTE memory location. The rotating buffer is updated. in the

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Storage location EKG BYTE a new mean value is saved. Based on ECG BYTE and PREVIOUS ECG BYTE it is determined whether a valid R-wave has been detected. Next, in step 826, the current count of the RR TIMER is checked to see if the refractory period is over. The current RR-TIMER count compared to the refractory period determined by the SET REFRACTORY DURATION program discussed above ON is determined. If it is found in step 826 that the refractory period is over, it is based on 14, program 900 SEGMENT SEARCH, which is explained in more detail, is called to determine the presence of an R-wave segment to determine. After the SEGMENT SEARCH program 900 is executed, or from step 826 an indication thereof if the refractory period is not over yet, a decision is made at step 828 as to whether a possible R-wave segment has been found. The SEGMENT SEARCH program sets the SEGMENTSTATUS memory location equal to "1" or "2" if a valid segment is found or "3" if a "stunted" or short segment was detected. Therefore, if in step 830 a "1", "2" or "3" is found within the SEGMENTSTATUS memory location, a transition is made to this Program 1000 SEGMENT ANALYSIS, during which the identified segments are compared to determine whether a valid R-wave was detected. After the program

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1000 has been executed or if the SEGMENTSTATUS is found to be "0", there is a transition to
Step 830 where the SEGMENTSTATUS memory location is set equal to "0" in order to prepare the process for the next EKG interrogation. The program is then exited via step 832 in order to terminate either the MONITORING SERVICE program 616 or the CALIBRATION SERVICE program 614. If the system is in the monitoring mode, step 832 returns to step 802, as shown in FIG.

The program 900 SEGMENT SEARCH will be described in detail with reference to FIG. As shown there, the SUCHART memory location of the RAM 26 is first evaluated in step 902 in order to determine the status of the SEGMENTSUCHE program 900. The SUCHART memory location is initially set to "0" by the initialization step 504 of the monitoring program 500. If the SEARCH TYPE is set to "0", step 906 is entered to continue the process of detecting the start of a potential
R wave segment to begin. According to FIG. 19, the QRS complex, within which the R wave forms a positive peak, can be divided into a series of segments
approximate. The FIGS. 19A and B show examples of valid R waves in which such EKG signals are carried out

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a sequence of three segments are shown. The presence of a valid R-wave is determined by measuring the time interval between segments, the length, slope and size of the segments, and the number of segments. First, in step 906, the time of the interval between two consecutive segments is measured. If this time is longer than 62.5 ms, the decision is made that all previously determined segments are part of a QRS complex or an interference signal because the maximum interval between two associated signal segments has been exceeded. As a result, a transition is made to step 916 where the storage location SEGMENTSTATUS is set equal to "3" to indicate that the maximum interval between two valid segments has been exceeded. If it is found in step 906 that the maximum permitted distance between two segments has not been reached, in step 908 the current data are stored in a segment start memory location of the RAM area 26d. The time control for a period corresponding to the maximum length of a valid segment, eg 95.8 ms, is initialized. The current data includes the previous value of the average ECG signal, which is stored in the PREVIOUS EKG BYTE storage location, and the current time value from the RR-ZEITGLIED storage location.

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Next, in step 910, it is determined whether there is a change in incline is present and whether the change in inclination is positive, in that the EKG BYTE stored in the memory location The value and the value in the PREVIOUS EKG BYTE memory location are compared. If the first value exceeds the second value by one Exceeds a predetermined amount, which is indicative of a positive slope that is greater than a threshold value is, the memory location SUCHART is set equal to "1" in step 912 in order to activate the SEGMENTSUCHE program 1000 (FIG. 16) to look for the end of that particular segment. If in step 910 the decision "No" is hit, it is determined in step 914, whether there is a segment with a negative slope by storing the storage locations EKG BYTE and PREVIOUS EKG BYTE to be checked. If the value of the PREVIOUS EKG BYTE is greater than that in the memory space by a predetermined amount EKG BYTE is the stored value, a display appears that a segment start was found. A transition is made to step 918 where the SUCHART flag is set equal to "2" to cause the SEARCH SEGMENT program 1000 to look for the end of that segment keep. After each of steps 916, 912 or 918 occurs a return to step 828 of program 800 QUESTION EKG AND PROVIDE TIMING.

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If the SEGMENT SEARCH program 900 continues and the SEARCHART flag has been set to "1" or "2" in step 912 or 918, step 902 determines the flag state concerned and passes the process to step 922 or step 928 to find the end of a segment. For example, it is assumed that the beginning of a segment with a positive inclination was determined during a previous run through the SEGMENTSUCHE program 900, so that the SUCHART flag was set to "1". As a result, evaluation step 902 passes control to step 922 in order to find the end of the segment with the positive slope. First, in step 922, it is checked whether the incline has been reversed or whether the segment duration limit value that was set in step 908 has expired. If either a slope reversal has occurred or the duration of a segment has expired, a transition is made to step 924 where the amplitude or size of the segment is calculated as an absolute value. Thereafter, the SEGMENT DEORGANIZATION subroutine (Fig. 5) is executed which reinitializes the various counters or timers to provide for the SEGMENT SEARCH program 900 to be recalled to find a new segment. In step 924 the value of the PREVIOUS EKG BYTES is retrieved, which was originally in step 908 at the beginning of the acquisition of the.

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Segment has been saved. This value is from cen-, PREVIOUS ECG BYTE, which was saved when the end of the segment was recorded, is subtracted by the absolute value the amplitude between the start and end point of the ECG interrogation. After the step 924 is complete or step 922 has answered "no" to both inquiries, the SEGMENT SEARCH program returns 900 to perform service step 828.

With a subsequent execution of the SEGMENT SEARCH program 900, in which the SEARCH TYPE is set equal to "2", step 902 directs the program to step 928, where the end of negative slope is determined in a manner similar to that previously described. In step 928 it is determined whether the incline has been reversed by saving the PREVIOUS EKG BYTE and EKG BYTE storage locations rotating buffer and / or whether the segment duration limit has expired. If any of these Conditions is met, a transition is made to step 930, where the absolute value of the size or amplitude of the segment is determined before the SEGMENT END ORGANIZATION program (FIG. 15) is called. As part of the SEG-MENTSUCHE program 900 (FIG. 14) are the beginning and the end of a segment and its amplitude as

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Preparation for the execution of the SEGMENT ANALYSIS program 1000 determines where a plurality of such segments are checked to determine whether the combination in question of the segments identified in this way a valid R-wave forms.

15 shows the subroutine 930 SEGMENT DEORGANIZATION, in the course of this, after calculating the amplitude of the segment in step 924 or 930, the various Counters and memory locations are initialized to identify and measure the parameters of the next segment prepare. In step 932, the measured values of the duration and size of the segment determined compared with predetermined minimum values, for example 15 units or counts of the D / A converter 34 and 16.7 ms corresponding to four counts of the interrogation clock generator 24. If these minimum values are exceeded, a transition is made to step 934, where the value of SUCHART is transferred to SEGMENTSTATUS in order to be used when executing the SEGMENT ANALYSIS program 1000 to become. If step 932 shows that the minimum conditions are not met, it is further determined whether the maximum interval between the segments, e.g. 62.5 ms, has elapsed since the end of the last segment is. In step 938 the current value of the

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- no -

RR-MEMBER with the LAST DATE FOR THE START OF THE SEGMENT compared. If it is greater, a transition is made to step 940, where the SEGMENTSTATUS is set to "3" which indicates a timeout without detecting a valid segment. After steps 934 and 940 and if the answer is "no" in step 938, the subroutine proceeds to step 936 where the SEARCH ART flag is set equal to "0" to prepare for the recall of the SEGMENT SEARCH program 900, so that the next segment, and in particular the beginning of the next segment, can be determined.

As shown in FIGS. 19A and B can be a consequence represent valid R-waves of segments. In particular In the present case, the QRS complex is replaced by three in a row occurring segments are defined with a certain inclination, amplitude and duration. As shown generally in FIG is, the SEARCH SEGMENT program identifies a single valid segment by adding values for its Duration, inclination and size are preserved. These values are passed on to the SEGMENT ANALYSIS program 1000, where these values are stored in certain memory locations, the sequence of the segments is checked the segments as a QRS signal or an interfering signal be classified, the RR interval is calculated

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and the RR TIMER is reset. The implementation of the SEGMENT ANALYSIS program 1000 is in detail explained with reference to FIG. First, in step 1002, the ANALYZEART is accessed in order to determine whether the value "0", "1" or "2" is currently in this memory location. In the initialization step 504 According to FIG. 8, the ANALYSIS TYPE is set equal to "0", so that a branch is first made to step 1006, where the first segment is captured and analyzed. After the data corresponding to the first segment has been received, the Step 1006 checks the storage space SEGMENTSTATUS to determine whether the relevant value is less than "3" is. As explained in connection with step 934 of FIG. 15, the SEGMENT STATUS becomes "1" or "2" set if valid segments with positive or negative inclination are found. Was the time interval expired between the segments, the SEGMENT STATUS flag was set equal to "3" in step 916 or 940. As a result, if the SEGMENT SEARCH determines that the segment is valid, im Step 1006 stores the segment data in the first segment memory location within the RAM 26. To the data of the first segment include its size, the time of the start of the segment recorded in the RR-TIMER is the PREVIOUS ECG BYTE stored in the memory

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stored peak amplitude and the time of the end of the segment recorded in the RR TIMER. Besides that the ANALYSEART value is changed from "0" to "1" in step 1008, so that in the subsequent execution of step 1002, the SEGMENT ANALYSIS program 1000 proceeds to step 1012 in order to evaluate the second segment. First, in step 1012, it is determined whether the SEGMENTSTATUS is "3", i.e., a period of more than the maximum duration corresponding to 62.5 ms has elapsed since the end of the first segment. If so is the case, then in step 1014 the subroutine 1034 TREAT ALL AS NOISE is called, whereby how based on 17 explains how the various memory locations, timers and counters are reset to delete the data corresponding to the first segment and prepare the SEGMENT ANALYSIS, the next segment data to be received and analyzed as the first segment. If in step 1012 a SEGMENT STATUS of "3" is found, it means that a single segment (Fig. 19C) has been detected but that is within the acceptable range Time limit no second segment has occurred. As a result, no valid R-wave was detected.

However, if step 1012 indicates that the status of the second segment is either a "1" or a "2" i.e.

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is not a "3", a transition is made to step 1016 where it is determined whether the first and second segments are the
have the same inclination. In step 1016, the SEGMENT STATUS storage locations of the first and second segments are compared. If they are the same, ie both segments the
have the same inclination, there is a transition to the step
1018, where the data corresponding to the first and second segments are combined. That is, it is assumed that a large single segment is caused by an interfering signal or
a cardiac conduction abnormality was interrupted and that only
a single segment was determined. The starting point of the
The first segment part is retained, while the end point of the second segment part is used as the end point of the combined first segment. The size of the combined first segment is taken as the sum of the previously determined sizes of the first and second segment parts. In addition, the ANALYSEART flag is left at "1" so that when the SEGMENT ANALYSIS program 1000 is executed again, the
second segment is recorded and analyzed. On the other hand, if it is determined in step 1016 that the inclinations of the first and second segments are different, the identification data of the second segment in the form of start and end points and size are stored in the memory space of the RAM area 26d for the second segment data. Then the ANALYSEART flag is set to "2"

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sets to prepare the SEGMENT ANALYSIS program 1000, record and add the data corresponding to the segment analyze.

After the SEGMENT ANALYSIS program 1000 has been executed a third time with ANALYSIS TYPE set to "2", in step 1002 the program 1000 is transferred to step 1022 so that the data corresponding to the third segment can be received and analyzed. In step 1022, the slope of the current segment becomes the slope of the previous segment. If it turns out that the inclinations of the successive Segments are the same, it is assumed in step 1024 that the second segment has been interrupted. the data corresponding to the current segment is combined with the data of the second segment, i.e., the starting point is treated as that of the second segment; the end point is that of the subsequent or ongoing Segments used; the amplitude is obtained by dividing the amplitudes of the previous and the current Segment part are totaled. In step 1024 there is no change to the ANALYSIS TYPE with respect to the current one Value of "2". The process then returns to continue with step 830 the service program. if if the inclinations differ, in step 102a

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the current data including the start and end point and the size are stored in the memory location of the RAM area 26d which is assigned to the data for the third segment. The ANALYSIS TYPE is then set equal to "0" in order to prepare the SEGMENT ANALYSIS program 1000 to record and analyze the next sequence of segments.

An evaluation of the stored data of the three segments initiated to determine whether a valid or an invalid R-wave was determined. First, in step 1028, it is determined whether the amplitude of the first segment is greater than that of the third segment by comparing the amplitude values stored in the memory locations are stored, which are assigned to the first and the third segment. When the amplitude of the first Segment is larger (that illustrated in Fig. 19A Case), the first two segments, i.e. from point 1 to point 2 and from point 3 to point 4, are called R-wave outline recognized. Because of this, the RR interval becomes calculated; the RR TIMER is reset; the QA duration is calculated. It goes without saying that the data to identify all three segments to one Point in time, which after recording and analysis

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sizing the segments. The analysis process is therefore performed by determining when the peak of the R-wave occurred. In the first case (Figure 19A) the peak appears at the end of the first segment and the RR interval is determined by checking the value of the RR TIMER at the end of the first segment. Similarly, the QA duration is determined as the difference between the beginning of the first segment and the end of the second segment. Furthermore, the RR TIMER must now be reset in order to start timing the next RR interval. For this purpose, the RR-TIMER is not reset to 0, but to a time which corresponds to the interval between the end of the first segment and the end of the third segment. If, on the other hand, the first segment is not larger than the third segment, which corresponds to the second case shown in FIG and third segment ending at point 6 , selected as the outline of the R-wave. The RR interval and the QA duration are determined accordingly; the RR TIMER is reset accordingly. The peak of the R wave is chosen to be the end of the second segment, thereby making the RR interval the value of the RR TIMER

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to be defined at the end of the second segment. This also gives the QA duration as the difference between the values the RR-MEMBER defined at the end of the third Segment and appear at the beginning of the second segment. The RR-TIMER is set to work with the timing starts at the beginning of the third segment. The RR-TIMER is at the end of the third segment reset to a time equal to the length of the third segment, the actual reset time of the RR TIMER, so that the subsequent RR interval can be measured. After every of steps 1030 and 1032, a further check is made in step 1033 to determine whether the measured R-Welle passes further validity tests. In particular, it is determined that the QA duration is less than 221 ms and that the determined RR interval is greater than 242 ms or 58 counts of the interrogation clock generator. It is also possible that for the corresponding trend query interval to compare certain mean RR interval with a predetermined limit period in order to determine the existence of a Identify cardiac abnormality. If the values are within the predetermined limit values lie, the R FLAG is set true in step 1036 in order to detect the occurrence of a display valid R-wave. Then the EKG

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Light-emitting diode switched on for an interval of 83.3 ms by setting the LEUCh ¹ TDIODE TIMER to a corresponding
Time span is set. The method then continues with block 830 of the service program. If the parameters of the determined R-wave do not match those mentioned
Limit values fall, by means of step 1032 im
Step 1034 calls up the TREATMENT AS NOISE subroutine explained with reference to FIG. 17.

If three segments are not within a given one
mutual interval occur, which is determined in step 1012, or if the QS duration and the RR interval according to the determinations in step 1032 are not within the predetermined limit values, so
Program 1034 HANDLE AS NOISE of Fig. 17 retrieved. First, in step 1038, the RR TIMER is reset to "0" while the ANALYSIS TYPE is set to "0" in order to prepare the SEGMENT ANALYSIS program 1000 to acquire and analyze data corresponding to the first segment of a new complex. Thereafter, in step 1040, it is determined whether the R-WEL-LENTYP is greater than "2". If so, the program resets the R-WAVE TYPE to "4", which is the initialization during the SAVE RR INTERVAL DATA subroutine 700, shown generally in FIG. 8 and in detail

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is shown in Fig. 10 is ensured. If the R-wave is less than or equal to "2", which is indicative is for a complete initialization, the R-WAVE TYPE is set equal to "0" to ensure that the next RR interval is disregarded because it is noisy. After the step 1048 or step 1042, it is determined in step 1044, whether the device is in monitoring mode by checking the XCMODE value. If yes, the light-emitting diode 88 is made to flash for a period of 41.6 ms to alert the operator to indicate that interfering signals have been detected. The duration of the flashing of the light-emitting diode 88 corresponds approximately half the duration of the lighting up of the light-emitting diode 88 when a valid R-wave is detected. If in Step 1044 determines that the device is not in the monitoring mode, the system will immediately returned to the execution of the SEG-MENTANALYSIS program continue without the light emitting diode 88 is made to flash.

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Claims (45)

PATENT ADVERTISEMENT DIPl.-ING. GERHARD SCHWAN ELFENSTRASSE 32 D-8000 MÖNCHEN 83 P-447 MEDTRONIC, INC. Old Highway Eight, Minneapolis, Minn. 55440 V.St.A. Expectations (1 .j device for long-term monitoring and storage by electrical signals attributable to the cardiac activity of a patient by (a) a memory device having a first and a second plurality of memory locations; (b) an interrogation device which can be connected for the purpose of receiving a cardiac activity signal from the patient for querying the cardiac activity signal in periodic real-time intervals and for storing it the interrogated signals in corresponding locations of the first plurality of storage locations; and 130061/0351 TELEPHONE: 0 «9 / 601ΪΟ39 · TELEX. M158 »dp * i ■ CABLE: ELECTR1CPATENT MUNICH (c) a data processing device for processing those in the places of the first plurality interrogated signals stored in memory locations and for storing the processed ones Signals in a data processing time frame in the places of the second plurality of Storage spaces. 2. Apparatus according to claim 1, characterized in that a query clock generator and a computer clock generator it is provided that the cardiac activity signals by means of the interrogation device to the output signal of the query clock generator can be queried are, and that the interrogated signals by means of the data processing device on the output signal of the computer clock generator can be stored. 3. Apparatus according to claim 2, characterized in that the query clock generator has an identifiable Sensor device responding to the patient's body function to manifest the occurrence is assigned to the body function in real time. 130061/0351 4. Apparatus according to claim 3, characterized in that the storage device has a third plurality of Has memory locations, and that the data processing device is designed such that it is based on the manifestation of the occurrence of the function towards a number of the queried signals from the places the first plurality of storage locations is transferred to the locations of the third plurality of storage locations. 5. Apparatus according to claim 3, characterized in that the sensor device is at least one of the patient has manually operated switch based on a detected symptom. 6. Apparatus according to claim 2, characterized in that the processed signals can be stored in an easily readable form by means of the data processing device in the locations of the second plurality of storage locations. 7. Apparatus according to claim 6, characterized in that a display device is provided and the data processing device has a reading device for reading out data from the locations of the second plurality of memory locations for the purpose of reproduction on the display device. 130061/0351 8. The device according to claim 2, characterized in that the data processing device is one on the Query clock generator responsive real-time processing unit for processing the in the places of the having stored data in the first plurality of storage locations. 9. Apparatus according to claim 8, characterized in that the real-time processing unit has a comparator stage for comparing the queried, stored in the locations of the first plurality of memory locations Signals with validity criteria to determine whether the queried signals are valid. 10. The device according to claim 9, characterized in that the storage device has a third plurality of Has memory locations that the queried signals can then be evaluated by means of the comparator stage are whether these signals are a valid segment of a heartbeat to provide a manifestation the same include that the data processing device with a means for storing which is responsive to the manifestation of a valid segment of characteristic query signals in one 130061/0351 corresponding space of the third plurality of storage spaces is provided, and that each storage space the third plurality of memory locations for receiving and storing identifying segments Data is designed. 11. The device according to claim 10, characterized in that the comparator stage for evaluating the in the locations of the third plurality of memory locations stored, segments identifying data is designed to determine whether a determined and processed combination of the segments is a valid one The patient's heartbeat forms, and around, if so, for a second manifestation for it to care. 12. The device according to claim 11, characterized in that the data processing device comprises a device for access to the segments stored in the locations of the third plurality of storage locations identifying data and for determining the intervals between valid heartbeats, 13. The apparatus according to claim 12, characterized in that the storage device with a fourth multiple 130061/0351 3101aoo number of storage locations is provided, each of which is intended for the recording and storage of data which are indicative of the interval between successive heartbeats, and that the data processing device is responsive to the output signal of the computer clock generator
Checking means for checking adjacent locations of the fourth plurality of storage locations in order to determine whether a valid heartbeat occurs in a regular rhythm and, if this is not the case, to deliver a third manifestation for a cardiac abnormality. 14. The apparatus according to claim 13, characterized in that it can be determined by means of the test device whether the valid heartbeat signal occurs prematurely to
the third manifestation as a mark of one
deliver premature heartbeat. 15. The device according to claim 13, characterized in that it can be determined by means of the testing device whether the valid heartbeat signal occurs outside of an expected interval around the third manifestation to be delivered as an indicator of a delayed or skipped heartbeat. 130061/0351 16. The apparatus according to claim 13, characterized in that by means of the testing device, the relevant Interval is comparable to an associated maximum value, and that the test device, if this maximum value is exceeded, delivers a fourth manifestation for a heart anomaly. 17. The device according to claim 16, characterized in that by means of the test device, the interval with a predetermined interval minimum value is comparable, and that the test device if it falls below of the minimum value a fifth manifestation for a Delivering heart anomaly. 18. The device according to claim 17, characterized by a responsive to a body function of the patient Sensor for the delivery of a sixth manifestation. 19. The device according to claim 18, characterized in that that the data processing device is equipped with a device that is responsive to each of the third, fourth, fifth or sixth manifestations appealing the permanent storage of the heart activity query signals effected in the locations of the first plurality of storage locations. 130061/0351 - fc - 20. The device according to claim 13, characterized in that that the storage device is provided with a fifth plurality of storage locations, that each location the fifth plurality of memory locations for receiving cardiac activity characteristic of the patient Data is designed, and that the data processing device is based on the output signal of the computer clock generator Appealing device for storing the cardiac activity data in a readout and is in a compressed format that facilitates playback. 21. The device according to claim 20, characterized in that that the monitoring period comprises a plurality of successive trend query intervals that in cardiac activity data can be stored in each location of the fifth plurality of storage locations, which one a plurality of successive trend interrogation intervals correspond, and that the data processing device with an addressing stage for selection and storing the cardiac activity data in the current memory location of the fifth plurality of Storage spaces is provided. 130061/0351 22. The device according to claim 20, characterized in that each place of the fifth plurality of memory locations is assigned to a range of a specific parameter of the cardiac activity data, and that the data processing device an addressing stage for addressing a specific location of the fifth plurality of memory locations corresponding to the specific determined area of the cardiac activity data. 23. The device according to claim 22, characterized in that a display of the heartbeat rate for the parameters heard by the .patient. 24. The device according to claim 22, characterized in that the difference between the parameters intervals associated with successive heartbeats heard. 25. The device according to claim 20, characterized in that the addressed current memory location of the fourth Multiple memory locations for recording the currently determined interval between successive ones Heartbeats in the course of calculating the same is designed while the earliest certain Interval signal is deleted. 130061/0351 26. The device according to claim 2, characterized in that the earliest queried signal can be deleted from the storage location of the first plurality of storage locations, while the last queried signal is stored in the current addressed storage location of the first plurality of storage locations, and that the data processing device has one the detection of a cardiac anomaly responding device for permanent storage of a sequence of the interrogated cardiac activity signals in the locations of the first plurality of memory locations. 27. Device for long-term monitoring and storage of cardiac activity characteristic of a patient Signals, marked by (a) a memory device having a first and a second plurality of memory locations; (b) an interrogation clock generator delivering a sequence of clock signals; (c) a data processing device with a central unit for executing programs for the recording, processing and storage of cardiac activity signals, the Data processing device is equipped with: 130061/0351 -U- 31018OQ (i) an interrogator responsive to each interrogation clock signal for interrogating the Cardiac activity signals and for storing the queries in corresponding places of the first plurality of storage locations, and (ii) an evaluation device for evaluating the memory locations in the locations of the first plurality of memory locations stored, queried cardiac activity signals with regard to predetermined criteria and, if these criteria are fulfilled, for processing and storing the queried cardiac activity signals in compressed format in locations of the second plurality of storage locations. 28. The device according to claim 27, characterized in that a computer clock generator for delivery of a second sequence of computer clock signals is provided, and that the evaluation device on the computer clock signals appeals to. 130061/0351 29. The device according to claim 27, characterized in that a playback device is provided, and that the data processing device is a reading device for reading out data from the locations of the second plurality of storage locations for the purpose of reproduction has on the playback device. 30. The device according to claim 28, characterized in that the data processing device has a Real-time processing unit responding to the query cycle for processing the data in the places of the first Has a plurality of storage locations stored data. 31. The device according to claim 30, characterized in that the storage device has a third plurality of storage locations that the real-time processing unit with the evaluation device for Evaluating the interrogated cardiac activity signals is provided in order to determine whether these signals a include a valid segment of a heartbeat, and to provide a first manifestation for it, as well that a means for storing responsive to the first manifestation of a valid segment of the interrogation signals indicative of this in a corresponding place of the third plurality of 130061/0351 Storage locations are provided, each location of the third plurality of storage locations for inclusion and storage of data identifying a segment is designed. 32. Apparatus according to claim 31, characterized in that by means of the evaluation device in the Locations of the third plurality of storage locations stored segments identifying data it can then be evaluated whether a determined and processed combination of the segments causes a heartbeat the cardiac activity of the patient, and by means of this, if this is the case, a second Manifestation for it can be created. 33. Apparatus according to claim 32, characterized in that the data processing device has a Device for access to the stored in the locations of the third plurality of memory locations, Segments identifying data and for determining the intervals between valid heartbeats having. 130061/0351 34. Apparatus according to claim 32, characterized in that the memory device is provided with a fourth plurality of memory locations, each of which is intended for the recording and storage of data indicative of the interval between successive valid heartbeats, and that the data processing device a test device responsive to the computer clock signals for checking adjacent locations of the fourth plurality of memory locations in order to determine whether a valid heartbeat occurs in a regular rhythm, and to
if not, deliver a third manifestation of a cardiac abnormality. 35. Apparatus according to claim 34, characterized in that the determined interval with an associated maximum value by means of the test device
is comparable, and that the test facility,
if this maximum value is exceeded, a
fourth manifestation for a cardiac abnormality. 130061/0351 36. Apparatus according to claim 35, characterized in that the interval by means of the testing device comparable to a predetermined minimum interval value is, and that the test device if it falls below a fifth manifestation of the minimum value for a heart anomaly. 37. Apparatus according to claim 35, characterized in that a device for forming an average value a number of the determined intervals is provided, and that by means of the test device the mean value is comparable to a predetermined value, and that the test device at A manifestation falls below the predetermined value for a heart anomaly. 38. Apparatus according to claim 37, characterized in that the test device with the mean value compares a predetermined maximum value and when it is exceeded a manifestation for a heart abnormality. 130061/0351 3101300 39. Apparatus according to claim 36, characterized in that the data processing device is equipped with a device which, in response to one of the manifestations, permanently stores the cardiac activity query signals in the
Causes places of the first plurality of memory locations. 40. Apparatus according to claim 34, characterized in that the storage device is provided with a fifth plurality of storage locations, that each location of the fifth plurality of storage locations is designed to receive data indicative of the cardiac activity of the patient, and that
the data processing device on the
Computer clock signals appealing device for
Storing the cardiac activity data in a compressed format that facilitates reading and playback. 41. The device according to claim 40, characterized in that the monitoring period comprises a plurality of successive trend interrogation intervals that in each place the fifth plurality of
Cardiac activity data can be saved 130061/0351 31018OQ corresponding to one of a plurality of consecutive trend interrogation intervals, and
that the data processing device with a
Addressing stage for storing the cardiac activity data in the current memory location of the fifth
A plurality of storage locations is provided. 42. Apparatus according to claim 40, characterized in that each location of the fifth plurality of storage locations is assigned to a region of a specific parameter of the cardiac activity data, and
that the data processing device has an addressing stage for addressing a specific location of the fifth plurality of memory locations accordingly
the specific determined area of the cardiac activity signal. 43. Apparatus according to claim 42, characterized in that for the parameters, the interval between successive Heard peaks of heartbeat. 44. Apparatus according to claim 42, characterized in that the difference between the parameters
intervals associated with successive heartbeats. 130081/0351 3101BQQ 45. Apparatus according to claim 44, characterized in that the addressed current memory location
the fourth plurality of memory locations for receiving the continuously determined beat interval in
During the calculation of the same is designed while the earliest determined beat interval signal is deleted. 130061/0351