MX2015003088A - System, method and apparatus for measuring the magnitude of instability and/or acceleration of a heart rate. - Google Patents

Abstract

The invention relates to a system, method and apparatus for measuring the magnitude of instability and/or acceleration of a heart rate, which allow for easy control and interpretation of the instability and/or acceleration of the heart rate, that can be carried out in an out-patient and in-patient environment, by the patient, health staff or family members. Said system comprises: means for detecting and conditioning a cardiac sign; means for the transmission of signals for the treatment thereof; a measurer of the magnitude of instability and acceleration of the heart rate; and means for displaying and/or storing the digital value that defines the magnitude of instability and acceleration of the heart rate.

Description

SYSTEM, METHOD AND APPARATUS FOR MEASURING THE MAGNITUDE OF INSTABILITY AND / OR ACCELERATION IN THE CARDIAC RHYTHM FIELD OF THE INVENTION The present invention is related to systems, methods and apparatus designed in the field of medicine and Biomedical Engineering used to measure vital signs, and more particularly, is related to a system, method and apparatus for measuring the magnitude of instability of a rhythm heart with units of the International System.

ANTECEDENTS OF THE INVENTION In the state of the art, a cardiac arrhythmia is defined as the rhythm or abnormal frequency of contraction of the heart, which may consist of too fast or slow contractions, or of an unbalanced or irregular form.

Currently, in the state of the art, cardiac arrhythmia is assessed with a qualitative method, being diagnosed by observing an electrocardiogram.

The electrocardiogram is the graphic representation of the electrical activity of the heart, which is obtained with an apparatus known as an electrocardiograph.

To determine rhythm and cardiac arrhythmia with electrocardiograph, an electrical signal of the heart beats is obtained, resulting in a graph with intervals of time in the cardiac cycles in which the distance between the waves of each cycle is analyzed in a visual way; if one of these is shortened or lengthened in time with respect to the others, cardiac arrhythmia is determined, whereas if the cycles are apparently kept at the same distance from each other, the heart is considered to be in rhythm. Some devices measure the average or standard deviation between the times of the cardiac sampling periods.

On the other hand, the oscillometric pulse pulsimeter method is included in some devices for blood pressure measurement, to determine the presence of cardiac pulse irregularities. With this method the signals of the arterial pulse are detected, later the time of the period of each pulse is analyzed and by means of the average of the effective periods in the sample of taken signal, only the presence or absence of cardiac arrhythmia is determined. The way of output to the monitor consists of an image that denotes presence or absence of arrhythmia.

In addition to the apparatuses described above, we can find in the state of the art various documents related to the detection of cardiac arrhythmia.

For example, U.S. Patent No. 5,403,355 describes a device A medical device that can supply an electrical impulse to the heart of a patient who has been found to have a tachycardia or ventricular fibrillation. Also, a modification in the detection criteria used to recognize a pathological tachycardia is described. According to this modification, if a sensor (which can be an accelerometer) indicates that the patient is at rest, the criterion to decide that a tachycardia is in progress is adjusted to a speed of 130 beats per minute, whereas if said sensor indicates that it is active, the criterion is changed to 170 beats per minute.

Also, US Patent No. 8,027,720 discloses an apparatus and method for the detection of cardiac arrhythmias through a defibrillator / cardioverter that is implanted subcutaneously. By means of the method, the information of the cardiac signal obtained by means of electrodes implanted in the patient is detected; this information is amplified, filtered and, through the processing and integration of the parameters of this information, it is determined whether it is necessary to initiate a therapeutic action with the defibrillator / cardioverter.

On the other hand, US Patent No. 7,734,346 is related to techniques to provide rhythm in response to premature atrial contraction, in order to prevent an atrial arrhythmia. For this, a implantable medical device comprising an electrode for detecting cardiac signals (which can be implanted in a chamber of the heart), a pulse generator coupled to the electrode and providing pulse pulses to the heart, and a processor is described. that receives signals from the electrode and discriminates between a cardiac signal that is a premature contraction of the type that triggers an arrhythmia, and one that does not trigger it, based on which it selectively controls the pulse generator Likewise, the method and apparatus described in US Pat. No. 7,412,282 allows the detection of a cardiac arrhythmia from an electrocardiogram, through a series of wave morphology analysis steps, which include the use of algorithms.

US Patent No. 6,095,984 also discloses an apparatus capable of detecting arrhythmia, which has means for detecting the pulse wave and for detecting an arrhythmia by monitoring changes in the pulse wave, determining that an arrhythmia occurs when an arrhythmia occurs. interruption in the continuity of said changes. The methods used to study the continuity of changes in the pulse wave (a time domain method and a frequency domain method), allow the detection of arrhythmia to be simpler and easier compared to an electrocardiogram. .

Also, in the Mexican Patent Application No. PA / a / 2005/000642 a monitor is described that serves to detect the existence of an arrhythmia in a patient. This monitor comprises two electrodes for momentary contact with the patient, and a detector circuit that communicates with said electrodes and executes a stored program to receive a signal from electrocardiogram, in such a way that the signal is evaluated immediately and the probability that the patient is experiencing an arrhythmia is detected. Finally, the patient is informed if this probability is above a predetermined value.

According to the above, it can be seen that the systems, methods and apparatuses already known in the state of the art only allow to determine the existence of cardiac arrhythmia. However, these have drawbacks such as the fact that they do not measure the magnitude of instability of a cardiac rhythm or cardiac arrhythmia, but that the rhythm or cardiac arrhythmia is analyzed in a subjective manner.

Also, e! rhythm analysis or cardiac arrhythmia is expensive due to the use of electrocardiographs, obtaining also results that can only be interpreted by a specialist in cardiology, which is not possible to monitor the rhythm or cardiac arrhythmia by the patient or their relatives.

OBJECTS OF THE INVENTION Taking into account the shortcomings of the prior art, it is an object of the present invention to provide a system, method and apparatus that allows the quantitative measurement, and in units of the International System, of the instability and / or acceleration of the heart rate.

It is another object of the present invention to provide a system, method and apparatus that allows to monitor and interpret the magnitude of the instability or acceleration of the cardiac rhythm on an outpatient and inpatient basis, by the patient himself, his family members and health personnel.

BRIEF DESCRIPTION OF THE INVENTION To this end, a system has been invented to measure the magnitude of instability of a heart rhythm, characterized in that it comprises: a) means for detecting and conditioning a sign related to cardiac cycles to relate them to the unit of time and analyzing said sign in units of frequency (t), wherein said sign is detectable when putting the detection and conditioning means in contact with a cardiac or arterial medium that emits said sign; b) means for transmitting heart rate signals that transmit the signal for treatment to a meter of the magnitude of instability and / or acceleration of a heart rate; c) the meter of the magnitude of instability and / or acceleration of a heart rhythm which receives the signal from the heart rate transmission means, to determine at least two (2) of the following parameters: / = heart rate (C / s), n = number of frequencies in the sample, T = sum of time of previous and subsequent period t = duration of a cycle, t = time (s) N = number of data spaced r0, and / or y = phase measurement. and correlates them to establish a numerical value that defines the magnitude of instability and / or acceleration of a heart rate corresponding to such measurement; Y d) means for deploying and / or storing the numerical value that defines the magnitude of instability and / or acceleration of a heart rate.

Other aspects of the invention consider a method and an apparatus for measuring the magnitude of instability of a heart rhythm BRIEF DESCRIPTION OF THE FIGURES The novel aspects that are considered characteristic of the present invention will be established with particularity in the appended claims. However, some modalities, characteristics and some objects and advantages thereof, will be better understood in the detailed description, when read in relation to the attached drawings, in which: Fig. 1 shows the system for measuring the instability magnitude and / or acceleration of a heart rate.

Fig. 2 shows the steps of the method for measuring the magnitude of instability and / or acceleration of a heart rate.

In Fig. 3 the general parts that make up the apparatus to measure the magnitude of instability and / or acceleration of a heart rate are observed.

Fig. 4 shows a block diagram of the elements of the apparatus for measuring the magnitude of instability and / or acceleration of a heart rate.

DETAILED DESCRIPTION OF THE INVENTION For purposes of the present invention, the cardiac or arterial environment is composed of at least one area of a patient's body, such as the precordial region or the limbs, where it is possible to detect an electrical or mechanical signal of the heart, such as cardiac blood fluid, arterial blood fluid, arterial blood pulse, etc.

The cardiac environment allows the detection of a series of periodic electrical and mechanical phases through which the heart passes before starting the reproduction of an earlier phase, which is called the cardiac cycle.

The cardiac period is defined as the interval of time necessary to complete a cardiac cycle.

The heart rate is the magnitude that measures the number of cardiac cycles that occur per unit of time.

The acceleration of the cardiac rhythm is the change in the magnitude of the cardiac cycle frequency per unit of time.

The instability of the cardiac rhythm is defined as the changes in the periods of the cardiac cycles as time elapses.

The instability and / or acceleration of the cardiac rhythm are the ways to measure the magnitude of the cardiac arrhythmia, and in both cases its unit is the C / s2 or Hz / s.

The system 1000 for measuring the magnitude of instability and / or acceleration of a heart rate of the present invention comprises: a) detection and conditioning means 1100 of a sign related to the cardiac cycles to relate them to the unit of time and convert said sign into units of frequency (/), where said sign is detectable when putting the means of detection and conditioning 1100 in contact with a cardiac or arterial means that emits said sign; b) means for transmitting heart rate signals 1200 that transmit the signal for processing to a meter of the magnitude of instability and / or acceleration of a heart rate 1300; c) the meter of the magnitude of instability and / or acceleration of a cardiac rhythm 1300 that receives the signal from the heart rate transmission means 1200, to determine at least two (2) of the following parameters: f = heart rate (C / s), n = number of frequencies in the sample, T¡ = sum of time of previous and subsequent period (s) t = duration of a cycle, t = time (s) N = number of data spaced t0, and / or y = phase measurement. and correlates them to establish a numerical value that defines the magnitude of instability and / or acceleration of a heart rate corresponding to such measurement; Y d) means for deploying and / or storing 1400 the numerical value that defines the magnitude of instability and / or acceleration of a heart rate.

Also, in one embodiment of the present invention, the numerical value that defines the magnitude of instability and / or acceleration of a heart rate is determined with the following formula: where: a = acceleration of a heart rhythm f = heart rate, n = number of frequencies in the sample, t = duration of a cardiac cycle In another embodiment of the present invention, the magnitude of instability and / or acceleration of a heart rate is determined with the following formula: where: a = acceleration of a heart rhythm f- heart rate T: = sum of time of previous and subsequent period Likewise, it is possible to determine the numerical value that defines the magnitude of instability and / or acceleration of a heart rate using the Alian variance, which by means of the frequency element or the time element, estimates the average variation between consecutive cycles according to the following : where: magnitude of instability of a heart rhythm N = number of data spaced r0 and, = phase measurement.

The development for the calculation of the variance of Alian is the following: The variance of Alian is an estimator of the dispersion of the fractional difference of an oscillator, reason why the variance of Alian quantifies the instability of the same. Consider the Next sample: My =. { yx, y2, y2, ..., yN_x} of N-l frequency measurements. Now, be the N-2 sub-samples of frequency measurements of an oscillator - - of the sample M and. We will denote by s (2 to the standard variance of the subsample . { and and 1} The variance of Alian, ay2, of sample M and is defined by the relation: where . { ) means average. In terms of the fractional frequency variances, yi, the variance of Alian can be written in the form - and it is a measure of the stability in frequency for observation times (or premediation) of t. From the My sample one can obtain the frequency stability of the oscillator under test for times.

Likewise, it is possible to determine the maximum change in frequency or speed presented by the cardiac cycles in a sample, which is defined as: 4 / max = Max. { to} where: A / max = maximum frequency change of cardiac cycles a = acceleration of a heart rhythm The shape and dimensions of the media vary according to the choice of electrical, mechanical or mechatronic mechanism of action.

In a preferred embodiment of the invention, the detection and conditioning means 1100 are selected between an electrode and a mechanode. More preferably, the The electrode is an electrical conductor and the mechanode is a conductor of mechanical magnitude.

As for the means of transmitting heart rate signals 1200, these are selected between a sensor and a mechanical, analog or electrical signal transducer. Preferably, the sensor or transducer may be of electrical signal, pressure, sound, blood velocity, blood flow, temperature, vibrations, length, frequency spectrum density, mass density, or color.

As regards the meter of the magnitude of instability and / or acceleration of a cardiac rhythm 1300, it comprises at least one mechanical, mechatronic or electrical element.

Also, another aspect of the invention describes a method for measuring the magnitude of instability and / or acceleration of a heart rate with units of C / s2 or Hz / s, which is based on the measurement of the magnitude of the variation of signals Periodic studies of the cardiac or arterial environment, for which it is possible to use different treatments such as algebraic, arithmetic or trigonometric equations; In particular, the treatment is used as described below. Referring to Fig. 2, it shows the steps of the measurement method 2000 of magnitude of instability and / or acceleration of a heart rate of the present invention, which comprises the following steps: i) a first step 2100 comprising contacting sensing and conditioning means with a cardiac or arterial means that emits a sign related to the heart rate, and converting said sign into a detectable heart rate signal; ii) a second step 2200 comprising transmitting the signal, using means of transmitting heart rate signals, to a meter of the magnitude of instability of a heart rate to define its value; iii) a third step 2300 comprising receiving the signal from step ii) by measuring the magnitude of instability of a heartbeat, recording it and determining a sample identifying repetitive variations in the signal to delimit the periods of arterial pulse or cycle cardiac content in the total of said sample, where the arterial pulse or cardiac cycle is called cycle (C); iv) a fourth step 2400 comprising determining to each of the cardiac cycles of the sample the period (T) or interval of time necessary to complete a cardiac cycle; v) a fifth stage 2500 comprising determining the frequency (/) to each of the cardiac cycles, which is obtained by calculating the reciprocal of the period (T); Y vi) a sixth step 2600 comprising determining at least two (2) of the following parameters: /, n, 7), t, t, N, and / or y, and correlating them to establish a value numerical that defines the magnitude of instability and / or acceleration (a), of a cardiac rhythm, with units of C / s2 or Hz / s, according to any of the following formulas: where: a = acceleration of a heart rhythm (C / s2 or Hz / s) / = heart rate (C / s) n = number of frequencies in the sample, t = duration of a cardiac cycle (s) O well: fM -f where: a = acceleration of a heart rhythm (C / s2 or Hz / s) f = heart rate T = sum of time of previous and subsequent period It is also possible to measure the magnitude of instability and / or acceleration of a heart rate using the Alian Variance using the frequency element or the time element, according to the following: - where: y2 = instability of a heart rhythm N = number of data spaced r0 y = phase measurement.

Preferably, if the result is a significant absence of variation in cycle time between the cycles comprising a given heart rate, it can be assigned the value of 0 and the amount of instability and / or acceleration of a heart rate would be equal to 0 C / s2; and if the variation in cycle time between the cycles comprising a heart rate and the magnitude is greater than 0, the result is the magnitude of instability and / or acceleration of a cardiac rhythm, or cardiac arrhythmia (n> 0 C / s2).

In a preferred embodiment of the invention, a heart rate index is determined, for which the number of cardiac periods in fashion is obtained from the measurement performed in step vi), and said amount is divided by a total number of cardiac cycles, wherein the resultant is a base heart rate index n. It is also possible to determine the maximum change in frequency or speed of cardiac cycles in a sample, which is defined as: 4 / max = Max. { to) where: Af = maximum frequency change of cardiac cycles a = acceleration of a heart rhythm Likewise, the results determined from stage vi) can be classified to obtain the number of cardiac cycles in fashion, the number of cardiac cycles with value greater than fashion, the number of cardiac cycles with lesser value than fashion, and the number of cardiac cycles in fashion over the total number of sample cardiac cycles.

Additionally, it is possible to determine the magnitude of the cardiac rhythm, according to the following formula: where: Rc = heart rate (C / s2 or Hz / s) / = heart rate (C / s) t = time (s) The units used to measure cardiac rhythm instability are determined as described below.

It is known in the state of the art that the heart rate (/) is the number of cardiac cycles or events that occur as a function of time, and that its units are C / min.

Whereas 1 minute = 60 seconds: - cardiac events nC i = - = - = Hz 60Í s where: f = heart rate C = cardiac cycle n = number of cycles Thus: C - f -f s C t + t, s s2 O well: On the other hand, preferably, the detection and conditioning means are selected between an electrode and a mechanode. More preferably, the electrode is an electrical conductor and the mechanode is a conductor of mechanical magnitude.

Also, the means of transmitting heart rate signals are selected between a sensor and a mechanical, analog or electrical signal transducer. Preferably, the sensor or transducer may be of electrical signal, pressure, sound, blood velocity, blood flow, temperature, vibrations, length, frequency spectrum density, mass density, or color.

As for the meter of the magnitude of instability and / or acceleration of a cardiac rhythm, this one is selected among a mechanical, mechatronic and electrical element.

Another aspect of the present invention considers an apparatus for measuring the magnitude of instability and / or acceleration of a heart rate. Referring now to Fig. 3, it shows the general parts that make up the apparatus 3000, which comprises a) at least one bracelet 3100 that is placed on a patient's limb to exert pressure on the cardiac environment or arterial and produce a sign related to heart rhythm; b) a tube 3200 that conducts the sign related to the heart rate to a sensor or pressure transducer; c) a 3300 pressure sensor or transducer that detects the sign related to the heart rate and conditions it to be processed as a pressure signal that is transmitted to a meter of the magnitude of instability of a heart rate; d) a meter of the magnitude of instability of a heart rate 3400 comprising a set of electronic components that receive the signal transmitted by the sensor or pressure transducer, and determines at least two (2) of the following parameters: /, n, Tt, r, t, N, and / or, and correlates them to establish a numerical value that defines the magnitude of instability of a heart rate corresponding to such determination; and optionally e) a screen 3500 in which the numerical value of the instability magnitude of a heart rate is displayed Optionally, the apparatus may comprise additional devices useful for use, such as keyboard, memory, USB drive for the transfer of information, and processing units.

The bracelet 3100 is inflated and deflated by a valve and a pump (not shown) in order to exert a pressure on the cardiac or arterial environment and produce a sign related to the heart rhythm, and may be of adjustable dimension to any measure of the perimeter of limb, being able to use at least one other bracelet with different dimension in Different segment of perimeter of the limb. The function of the bracelet 3100 is to apply pressure to at least one extremity segment until the pressure inside the said bracelet 3100 interacts with the rhythmic or arrhythmic magnitude of the arterial pulse; the result is the production of synchronous oscillatory waves between the pressure inside the cuff 3100 and the arterial pulse wave, which are transmitted by the tube 3200 to the 3300 pressure sensor or transducer.

As for the sensor or pressure transducer, it includes a filter circuit to eliminate the noise and condition the rhythmic or arrhythmic signal of the pressure oscillations, and transmit the signal.

Also, in a preferred embodiment of the invention, the electronic component assembly 3400 comprises a microcontroller and / or processor (not shown) that receives the conditioned signal, controls the action of the valve and the pump (not shown) to inflate and deflate the bracelet 3100, and performs signal processing.

As for the determination of the numerical value of the instability magnitude of a cardiac rhythm, this can be done by means of one of the following formulas: where: a = acceleration of a heart rhythm / = heart rate, n = number of frequencies in the sample, r = duration of a cardiac cycle O well: where: a = acceleration of a heart rhythm (C / s2 or Hz / s) f = heart rate t = sum of time of previous and subsequent period * O well: - where: oy2 = instability of a heart rhythm N = number of data spaced r0 y = phase measurement.

As mentioned above, the apparatus measures and emits the result of the magnitude of instability and / or acceleration of a heart rate in units of C / s2 or Hz / s. Additionally, the device emits a numerical value selected between heart rate index, number of cardiac cycles in fashion, number of cardiac cycles with value greater than fashion, number of cardiac cycles with less value than fashion, and number of cycles cardiac in fashion over the total sample cardiac cycles. Likewise, it is possible to determine the maximum change of frequency or speed of cardiac cycles in a sample, which is defined as: A / max = Max. { to } where: L f = maximum change in frequency of cardiac cycles a = acceleration of a heart rhythm Referring now to Fig. 4 of the accompanying drawings, there is shown an outline of the operation of the apparatus 3000 for measuring instability of a heart rhythm, including the internal elements of the electronic components assembly 3400. The apparatus 3000 comprises a first 3401 main processing card unit, as well as the following input units: pressure sensor card unit 3402 and, optionally, a 3403 additional sensor card unit for the different signals of the sensors or transducers of electrical signals, sound, speed blood, blood flow, temperature, vibrations, length, frequency spectrum density, mass density, or color. Also, it comprises an inflation and deflation card of valve 3404 of cuff 3100, pump 3500, output ports 3405, memory 3406, screen output 3407, power port 3408, CMOS battery 3409, expansion slots 3410, and 3411 audio card. Also, the 3300 pressure sensor and, optionally, additional sensors or 3600 transducers of electrical signals, sound, blood velocity, blood flow, temperature, vibrations, length, frequency spectrum density, mass density are shown. , or color.

In the embodiment described, once the bracelet 3100 is placed, a sign related to the heart rate is produced, which is conducted to the pressure sensor 3350, receiving said sign in the card unit of the pressure sensor 3402 and, optionally, in the card unit of additional sensors 3403. In this receiving section conditions the sign to be processed as a pressure signal and this information is made available to the main processing card unit 3401 so that the information can be analyzed and processed by programming guided by the method of measuring the instability magnitude of a heart rhythm. Once obtained the results, we proceed to the shipping section (shipping) or output ports 3405, which takes the information already processed and places it in different output devices so that the information is available outside the device 3000. The information processed (the results or output information) can be displayed on a monitor, printed on paper, stored on CD, USB, networks, etc. As for the memory unit 3406, it functions as a fast access store and also retains the processed information, such as data from patient measurements until the output unit can place it in the output devices or, optionally, send it to a secondary storage unit. The secondary storage unit can be a high-capacity, long-lasting memory store of the device, consisting of a hard disk that contains all measurements per patient with dates and programs or data that are not in execution by the other units , as well as the programming of the method of measuring the instability magnitude of a heart rhythm, and the arithmetic and logical unit (ALU). Said ALU will be found in the microcontroller and / or processor (not shown) of the main processing card unit 3401 for the analysis and processing of the signals already conditioned by the input cards 3402 and / or 3403 coming from the pressure sensor 3300 and / or additional sensors 3600. The ALU of the main processing card unit 3401 contains the decision mechanisms that allow the apparatus 3000 to perform the phases of the measurement method of instability magnitude of a heart rate, comparing the signals of the pressure sensor 3300 to determine the magnitude of instability of a heart rhythm. The main processing card unit 3401 coordinates and supervises the operation of the inflation and deflation card of the valve 3404, controlling the speed of action of the pump 3500 that provides the necessary pressure on the end segment of the patient, using the bracelet 3100 for the correct conditioning of the signal. The programming of the inflation and deflation operation of the cuff can be contained in the main processing card unit 3401 or in the inflation and deflation card of the specific valve 3404 for this task. The main processing card unit 3401 captures the conditioned signal from the pressure sensor 2300, records and erases information from the signal of said sensor 2300, indicates to the ALU when it should use the memory information for calculations, and indicates to the output unit 3405 when to send the information from the memory unit to output devices (not shown).

In accordance with what has been described above, it can be observed that the system, method and apparatus for measuring the magnitude of instability and / or acceleration of the heart rate, has been designed to quantitatively determine the instability of heart rate and / or measure the magnitude of acceleration between successive heartbeats, allowing also to monitor the magnitude of instability or acceleration of a heart rate on an outpatient basis, by the patient himself or his relatives, and it will be evident to any expert in the field that the modalities of the system, method and apparatus to measure the magnitude of and / or acceleration of the heart rate as described above and illustrated in the accompanying drawings, are only illustrative more non-limiting of the present invention, since numerous changes of consideration in its details are possible without departing from the scope of the invention.

Therefore, the present invention should not be considered as restricted except for what is required by the prior art and by the scope of the appended claims.

Claims (32)

NOVELTY OF THE INVENTION CLAIMS

1. A system for measuring the magnitude of instability and / or acceleration of a heart rate, characterized in that it comprises: a) means of detecting and conditioning a sign related to cardiac cycles to relate them to the unit of time and convert said sign into units of frequency (/ 3, where said sign is detectable when putting the means of detection and conditioning in contact with a cardiac or arterial means that emits said sign; b) means of transmitting heart rate signals that transmit the signal for its treatment up to a meter of the magnitude of instability and / or acceleration of a heart rate; c) the meter of the magnitude of instability and / or acceleration of a heart rate receives the signal from the heart rate transmission means, to record it and determine a sample identifying repetitive variations in the signal to delimit the periods of arterial pulse or cycle cardiac content in the total of said sample, where the arterial pulse or cardiac cycle is called cycle (C), determine for each of the cardiac cycles of the sample the period (T) or interval of time necessary to complete a cardiac cycle, determine the frequency (/) for each of the cardiac cycles obtained by calculating the reciprocal of the period (T), and to determine at least two (2) of the following parameters: / = heart rate, n = number of frequencies in the sample, Tt = sum of time of previous and subsequent period, t = duration of a cycle, t = time, N = number of data spaced r0, and / or y = phase measurement; and correlates them to establish a numerical value that defines the magnitude of instability and / or acceleration of a heart rate corresponding to such measurement; and d) means for deploying and / or storing the numerical value that defines the magnitude of instability and / or acceleration of a heart rate.

2. The system according to claim 1, further characterized in that it determines and displays and / or stores at least one numerical value selected between heart rate index, maximum change in frequency or speed of cardiac cycles, number of cardiac cycles in fashion, amount of cardiac cycles with a greater value than fashion, number of cardiac cycles with less value than fashion, and number of cardiac cycles in fashion over the total number of sample cardiac cycles.

3. The system according to claim 1, further characterized in that the numerical value is determined according to the following formula: ,

4. The system according to claim 1, further characterized in that the numerical value is determined according to the following formula:

5. The system according to claim 1, further characterized in that the numerical value of the heart rate is determined according to the following formula:

6. The system according to claim 1, further characterized in that the detection and conditioning means are selected between an electrode and a mechanode.

7. The system according to claim 6, further characterized in that the electrode is an electrical conductor and the mechanode is a conductor of mechanical magnitude.

8. The system according to claim 1, further characterized in that the means for transmitting heart rate signals are selected between a sensor and a mechanical, analog or electrical signal transducer.

9. The system according to claim 8, further characterized in that the sensor or the transducer can be of electrical signal, pressure, sound, blood velocity, blood flow, temperature, vibrations, length, frequency spectrum density, mass density, or color.

10. The system according to claim 1, further characterized in that the meter of the instability magnitude of a heart rate comprises at least one mechanical, mechatronic or electrical element.

11. A method for measuring the magnitude of instability of a heart rhythm, characterized in that it comprises the following steps: i) contact means of detection and conditioning with a cardiac or arterial means that emit a sign related to the heart rhythm, and convert said sign in a detectable heart rate signal; ii) transmitting the signal, using means of transmitting heart rate signals, to a meter of the magnitude of instability and / or acceleration of a heart rate to define its value; iii) receive by the meter the magnitude of instability and / or acceleration of a heart rate the signal from step ii), record it and determine a sample identifying repetitive variations in the signal to delimit the periods of arterial pulse or cardiac cycle contained in the total of said sample, where the arterial pulse or cardiac cycle is called cycle (C); iv) determine to each one of the cardiac cycles of the sample the period (T) or interval of time necessary to complete a cardiac cycle; v) determine the frequency (/) to each of the cardiac cycles, which is obtained by calculating the reciprocal of the period (T); and vi) determine at least two (2) of the following parameters: f, n, Tt, t > t, N, and / or y, and correlate them to establish a numerical value that defines the magnitude of instability and / or acceleration of a heart rate; vii) and display and / or store the numerical value that defines the magnitude of instability and / or acceleration of a heart rhythm.

12. The method according to claim 11, further characterized in that in step vi), the numerical value is determined according to the following formula:

13. The method according to claim 11, further characterized in that in step vi), the numerical value is determined according to the following formula:

14. The method according to claim 11, further characterized in that in step vi), the numerical value is determined according to the following formula:

15. The method according to claim 11, further characterized in that, in step vi), if the result is a significant absence of variation in cycle time between the cycles comprising a given heart rate, it can be assigned the value of 0 and the magnitude of instability and / or acceleration of a heart rate would be equal to 0 C / s2o Hz / s and if the variation in cycle time between the cycles comprising a heart rate and the magnitude is greater than 0, the result is the magnitude of instability and / or acceleration of a heart rate (n> 0 C / s2 or Hz / s).

16. The method according to claim 11, further characterized in that a heart rate index is determined, for which the number of cardiac periods in fashion is obtained from the measurement made in step vi), and said amount is divided among n total number of cardiac cycles, where the resultant is an index of cardiac rhythm base n.

17. The method according to claim 11, further characterized in that the maximum change in frequency or speed of the cardiac cycles is determined in accordance with the following formula: 4 / max = Max. { to] where: A / max = maximum frequency change of cardiac cycles a = acceleration of a heart rhythm.

18. The method according to claim 11, further characterized in that the results determined from step vi) are classified to obtain the number of cardiac cycles in fashion, the number of cardiac cycles with value greater than the mode, the number of cycles heart rates with a lower value than fashion, and the number of cardiac cycles in fashion over the total number of sample cardiac cycles.

19. The method according to claim 11, further characterized in that the detection and conditioning means are selected between an electrode and a mechanode.

20. The method according to claim 19, further characterized in that the electrode is an electrical conductor and the mechanode is a conductor of mechanical magnitude.

21. The method according to claim 11, further characterized in that the means for transmitting heart rate signals are selected between a sensor and a mechanical, analog or electrical signal transducer.

22. The method according to claim 21, further characterized in that the sensor or transducer can be electrical signal, pressure, sound, blood velocity, blood flow, temperature, vibrations, length, frequency spectrum density, mass density, or color.

23. The method according to claim 11, further characterized in that the meter of the magnitude of instability and acceleration of a heart rate is selected from a mechanical, mechatronic and electrical element.

24. An apparatus for measuring the magnitude of instability and acceleration of a heart rhythm, characterized in that it comprises: a) at least one bracelet that is placed on a limb of a patient to exert pressure on the cardiac or arterial environment and produce a sign related to the heart rate; b) a tube that carries the sign related to the heart rate to a sensor or pressure transducer; c) a sensor or pressure transducer that detects the sign related to the heart rate and conditions it to be processed as a pressure signal that is transmitted to a meter of the magnitude of instability and acceleration of a heart rate; and, d) a meter of the magnitude of instability and acceleration of a cardiac rhythm comprising a set of electronic components that receive the signal transmitted by the sensor or pressure transducer, and determines at least two (2) of the following parameters : /, n, T, t, t, N, and / or, and correlates them to establish a numerical value that defines the magnitude of instability and acceleration of a heart rate corresponding to such determination; and optionally e) a screen in which the numerical value of the magnitude of instability, acceleration and maximum acceleration of a heart rate is displayed.

25. The apparatus according to claim 24, further characterized in that at least one numerical value selected between heart rate index is set and displayed, number of cardiac cycles in fashion, number of cardiac cycles with value greater than fashion, number of cardiac cycles with less value than fashion, and number of cardiac cycles in fashion over the total number of sample cardiac cycles.

26. The apparatus according to claim 24, further characterized in that, to exert pressure on the cardiac or arterial means, the cuff is inflated and deflated by a valve and a pump.

27. The apparatus according to claim 24, further characterized in that at least one other bracelet with different dimension is used in different perimeter segment of the limb.

28. The apparatus according to claim 24, further characterized in that the pressure sensor comprises a filter circuit to eliminate the noise and condition the rhythmic or arrhythmic signal of the pressure oscillations, and transmit the signal.

29. The apparatus according to claim 24, further characterized in that the set of electronic components comprises a microcontroller and / or processor that receives the conditioned signal, controls the action of the valve and the pump to inflate and deflate the cuff, and performs the processing of signals.

30. The apparatus according to claim 24, further characterized in that the numerical value is determined in accordance with the following formula:

31. The apparatus according to claim 24, further characterized in that the numerical value is determined in accordance with the following formula:

32. The apparatus according to claim 24, further characterized in that the numerical value is determined in accordance with the following formula: