Diphasic wave of defibrillator with adjusted second-phase tilt

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment. An external defibrillator for two-phase defibrillation waveform supply comprises a high-voltage circuit, which accommodates a condenser, as well as a pair of electrodes and a number of switches. The high-voltage circuit is presented to charge the condenser to supply the defibrillation pulse. The switches comprise an H-bridge, connected between the condenser and electrodes and can be connected to first and second phases of the two-phase defibrillation waveform to the electrodes. A second-phase tilt is adjustable. The controlled conduction path comprises the H-bridge switch and enables the controlled conduction path for the second phase of the two-phase waveform.

EFFECT: using the invention enables higher safety and effectiveness of defibrillation.

12 cl, 6 dwg

 

The present invention relates to defibrillators for resuscitation of patients with sudden cardiac arrest and, in particular, to the defibrillator, which form a two-phase electric shock waves.

Sudden cardiac death is a leading cause of death in the United States. A common cause of sudden cardiac death is ventricular fibrillation, when the muscle fibers of the heart are compressed uncoordinated. This insufficiently coordinated activity of the myocardium leads to the loss of the ability of the heart to the efficient pumping of blood, which interrupts normal blood flow in the body. The only effective treatment for ventricular fibrillation is electrical defibrillation, which consists in the application of electric shock to the patient's heart. Strong defibrillation shock interrupts all the electrical activity of the heart. Then, the autonomic nervous system of the body automatically restores the coordinated application of electric pulses to the heart.

To improve the efficiency defibrillation shock should be given to the patient within a few minutes after the onset of ventricular fibrillation. Studies have shown that defibrillation shocks applied within one minute after starting fibrillation, provide coefficient is jivamukti to 100%. The survival rate decreases to approximately 30%, if, prior to the application of shock passes 6 minutes. After 12 minutes, the survival rate reaches zero.

One way of deciding on quick defibrillation shocks lies in the use of implantable defibrillators. Implantable defibrillator surgically implanted in patients for whom a high probability needs of electrotherapy in the future. Implantable defibrillators are typically monitor the heart activity of the patient and automatically serves electrotherapy pulses directly to the heart of the patient when indicated. Therefore, implantable defibrillators allow the patient to a certain extent, it is normal to act while the defibrillator continuously monitors the activity of the heart. However, implantable defibrillators are expensive and used only a small part of the entire group of people at risk of sudden cardiac death.

External defibrillators send electrical impulses to the patient's heart through electrodes placed on the patient's body. External defibrillators are useful in the emergency Department, operating room, ambulance, or other circumstances in which you may experience unexpected need to ensure is electrotherapy patient in the shortest possible time. The advantage of external defibrillators is that these defibrillators can be used on the patient, if necessary, and then be removed for use with another patient. The disadvantage in comparison with implantable defibrillators is that external defibrillator must be able to provide effective therapeutic effect on any patient, with which it is used. Because implantable defibrillator apply to a specific patient, the performance of the defibrillator regulate to ensure specific electrotherapy individually for a particular patient. Operating parameters, for example, the amplitudes of the electrical pulses and supplied complete energy can effectively measure and adjust accordingly physiology of a particular patient to optimize the effectiveness of defibrillator. For example, the initial voltage, the duration of the first phase and the total duration of the pulse can be set prior to implantation of the device for feeding the required amount of energy, or to provide the required initial and finite difference potentials (e.g., constant relative decline of the peak of the pulse). Even when the implanted defibrillator is capable of changing its operating parameters to compensate for changes in impedance leads defibrillate the a and/or the patient's heart (as explained in the following patent FEIN (Fain)), the range of possible changes in impedance in one implantation, the patient is relatively small. Parameters such as the impedance of the patient, can be measured during implantation and adjustment of the wave defibrillator respectively the characteristics of a particular patient.

For comparison, an external defibrillator should be performed with the full range of characteristics of patients, existing patients, which can be applied the defibrillator. Since the external electrodes of the defibrillator are not in direct contact with the patient's heart, and as external defibrillators should be capable of use with a wide variety of patients with diverse physiological differences, external defibrillators should work in accordance with these parameters, the amplitude and duration of pulses, which will be effective for most patients, regardless of the physiology of the patient. For example, the impedance created by the tissue between the electrodes of the external defibrillator and heart patient, varies from patient to patient, which changes the intensity and the waveform of the shock applied to the patient's heart when the data amplitude and duration of the initial pulse. The amplitude and duration of pulses are effective for the treatment of patients with low impede the catfish, not necessarily ensure efficient and energy-saving therapeutic effects on patients with high impedance. Accordingly, the thoracic impedance of the patient is usually measured by the defibrillator in the process of therapy, and pulse wave is dynamically regulated, as explained in U.S. patent 5803927 (Cameron and others) and 5749904 (Gliner and others)

Wave defibrillator, i.e. graphs of temporal dependence of the supplied pulse current or voltage, is characterized in accordance with the shape, polarity, duration, and number of phases of the pulse. Most modern defibrillators, internal and external, use some form of shortening exponential biphasic waves. Examples of biphasic implantable defibrillators can be found in U.S. patent No. 4821723 inventors Baker, Jr., and others; US patent No. 5083562 inventors de Coriolis and others; US patent No. 4800883 inventor Winstrom; U.S. patent No. 4850357 inventor Bach, Jr.; U.S. patent No. 4953551 inventors Mehra and others; and U.S. patent No. 5230336 inventors Fain and others

One well-known technique in the solution of the diversity of patients is the creation of an external defibrillator with multiple settings energy, which can be selected by the user. General Protocol for the application of the defibrillator is to attempt defibrillation with initial parameter the settings energy, suitable for defibrillation of a patient with secondary impedance, and then increase the setting of energy for subsequent attempts at defibrillation if the initial parameter settings did not provide resuscitation of the patient. Repeated attempts at defibrillation require additional energy and increase the risk for the patient. Another way, as stated above, is to measure the impedance of the patient during therapy or parameter-dependent impedance of the patient, and the change in the shape of subsequent defibrillation shock on the basis of previously performed measurements. For example, the implanted defibrillator, described in the patent FEIN (Fain), submits defibrillation shock pre-specified form to the patient's heart in response to a detected arrhythmia. The device FEIN measures the impedance of the system during the application of this shock, and uses the measured impedance to change the form of the following apply shock. A variant of this method is described in the article by R. E. Kerber, and others, "Energy, current, and success in defibrillation and cardioversion: clinical studies using an automated impedance-based method of energy adjustment", Circulation vol 77, PP 1038-46 (May 1988). In this article, the authors give a description of the external defibrillator, which delivers the test pulse in the patient before the application defibrillating shock. Test pulse used to measure the impedance of the patient before the application is of shock. Then the defibrillator adjusts the amount of energy supplied by the shock, in response to the measured impedance of the patient. The shape of the supplied wave Cerberus with co-authors (Kerber et al.) is a damped sine wave.

Although the impedance of the patient is of great importance and can be measured by the defibrillator during treatment, another important characteristic of the patient is the reaction of the cell membrane of the myocardium of the patient on electrotherapy. Although it is known that the electric shock will interrupt fibrillation electrical activity, the exact physiological explanation of this phenomenon remains a subject of speculation. One of the hypotheses suggests that the initial high-energy shock stops the electrical activity of myocardial cells by a strong electric current in the direction of the polarity of the shock. Advantages of two-phase waves, which contain more effective defibrillation and fewer harmful outcomes, are assumed to be due to reverse polarity of the second phase of the shock wave. Suppose that the reference current during the second phase reduces the residual effects of the initial shock and stabilize the fabric by removing the residual charges in the myocardial cells. It is assumed that myocardial cells are more sensitive to offline is to restore the proper electrical pulsations, if the results of the impact of initial defibrillation shock fully removed so that they did not interfere with the aforementioned restoration of normal electrical activity. Given the hypothesis leads to the requirement of knowledge of the exact reaction myocardial cells of the patient in shock. Although the reaction of myocardial cells was measured during clinical studies, this cellular reaction to date has not yet been able to measure during therapy. Thus, in most defibrillators accepted average value of the cell reaction, which derive from the measured values of the mentioned studies. Such use of the estimated average leaves something to be desired. The spread of cellular responses about the mean, in General, are little known, and the characteristics of the cell response specific patient is difficult to predict or determine. Accordingly, external defibrillator, it is desirable to plan the wave pulse, which is safe and effective for patients with different ranges of impedance of the patient and different responses to myocardial cells.

In accordance with the principles of the present invention an external defibrillator that provides two-phase defibrillation pulse with various adjustable parameters of the Mentioned parameters include energy, subject to the filing, initial voltage and current, duration, phase, pulse duration, and the relative decline of the peak of the pulse, including the variable relative decline of the peak of the pulse is phase 2. AC relative decline of the top pulse of the second phase provides a controlled passing by the patient some part of the pulse current during the second phase, which regulates the relative decline of the top pulse of the second phase of a biphasic waveform. The present invention can be implemented by the defibrillator with the same capacity. In the drawings:

Fig.1 is a block diagram of an external defibrillator, created in accordance with the principles of the present invention;

Fig.2a and 2b biphasic wave with characteristics of large and small relative decline of the top pulse;

Fig.3 - shortened two-phase wave;

Fig.4a-4c is biphasic defibrillation wave in comparison with different characteristics reaction to myocardial cells;

Fig.5 is a schematic diagram of the defibrillator, which delivers a biphasic defibrillation wave with adjustable relative decline of the top pulse of the second phase in accordance with the principles of the present invention;

Fig.6 - biphasic defibrillation wave generated by the defibrillator shown in Fig.5, in comparison with different characteristics reaction to myocardial who etoc.

In Fig.1 shows a block diagram of the monitor/defibrillator patient, performed in accordance with the principles of the present invention. The device shown in Fig.1, can perform the defibrillation of a patient who is experiencing ventricular fibrillation. This device can also perform ECG monitoring, including cardiac monitoring, necessary for automatic decision defibrillation. Shows the monitor can also measure oxygen saturation (SpO2), a non-invasive monitor blood pressure and to control the concentration of CO2at the end of exhalation. This multifunctional device can also perform other functions, such as invasive monitoring of blood pressure and temperature control of the patient. The monitor contains many input and output stages mates with the patient, which are the input and output circuits for sensors and electrodes attached to the patient. In addition, the scheme includes traditional measuring and amplifying circuit for ECG electrodes for optical oxygen sensors for measuring pressure and for measuring carbon dioxide. Information received by the sensors of the patient and processed by the input circuits 10, digitized input A/D (analog-digital) converters 12. Digitized information, wodis is in schema processing device connected to the bus 60, which establishes a data connection between the different modules of the device.

The unit contains high-voltage circuits 16 for operation of the defibrillator. High-voltage diagram form a pulse high voltage required for defibrillation, which is connected, at the appropriate time, the switching logic 14 to the electrodes of the defibrillator is connected to the patient. The above diagram provides a high-voltage shock necessary to terminate ventricular fibrillation and return the heart to a normal rhythm. Energy levels and wave shock damage for defibrillation, can be automatically calculated by the processor 40 in the monitor or can be set manually by experienced medical technician or doctor.

The power modules of the device is served by the circuits 20 power management. Scheme 20 power management will distribute power from the battery 22 from the power source 24 of alternating current or power source 26 of direct current. Sources of AC power and DC are connected with circuits that charge the battery when the monitor is receiving power from the external power sources.

Information received by the device, can be transmitted to other devices or designated circuits 30 connected. These schemes may include a network connection, an RS232 connection or wireless is a great connection (for example, Bluetooth, WiFi or infrared connection, etc).

The device operates and is controlled via keyboard and bodies 32 of the control. In the embodiment, the keyboard is a membrane keyboard, ensuring reliability in ambient conditions. Can also be provided with controls, for example, switch on/off, controls the power level and the supply shock for defibrillation, printer and other functions.

The monitor is running on the Central processing unit (CPU) 40. The Central processing unit (CPU) executes the software recorded in the permanent memory (ROM) 38. Also provided permanent flash memory to control the settings of functions and new or special features, for example, information related to the wave. Provided with a removable memory 36 for storing information generated during an attack the patient, for example, ventricular fibrillation. Information about the patient, for example, cardiomegaly before and after defibrillation, are also stored in the removable memory 36, which can be removed and, then, transfer to a medical specialist for analysis, documentation and further analysis. Removable memory 36 may also record audio information from a medical professional, speaking into the microphone 48.

Sound detectors 34 SL is subject to excitation solid-state sound source, who gives a short "beep" sounds. These sounds indicate that the self-test, memory device has detected a low battery level or a defective component or group of schemes that are vital for the patient. On the front side of the device there is also a special display, which is great, flashing, red letter X to indicate low battery level or a large, permanent, red letter X to identify the fault schema.

Software generated tone signals 46, which is then used to excite the speaker 42. This option is for some control functions, for example, a short tone in response to each cardiac cycle. Combination tones are used to produce the sound of alarms and warnings when measurement data of vital functions of the patient beyond the selected limits alarms. Tones can also be generated with specified frequency to guide medical specialist during the execution of clicks indirect heart massage (CPR).

Speaker 42 can play pre-recorded voice instructions and other information stored and reproducibility of the circuits 44 speech output.

In Fig.2a depicts TLD the phase wave 70 this type of wave, which is produced by the defibrillator constructed in accordance with the present invention. Biphasic wave is the first phase 72 of one polarity and a second phase 74 opposite polarity. Two-phase waves can be submitted by the defibrillator using at least one capacitor. If dvukhchastotnogo defibrillator, one capacitor will be charged to the maximum voltage V0at the beginning of the first phase 72, and the other capacitor will be charged to the maximum voltage V2at the beginning of the second phase. Two capacitor will be differently oriented polarities with respect to the design of high voltage that produced the opposite phase pulses. During the first phase, the first capacitor is connected to the circuit high voltage and discharged by passing current through the electrodes of the defibrillator. If you want to stop the first phase, the first capacitor is switched from the circuit of high voltage, and connects the second capacitor. Since the second capacitor is connected with the polarity reversed relative to the polarity of the first capacitor, the discharge of the second capacitor will generate a pulse polarity for the second phase, which is a reverse polarity in the first phase. When using two condensers, each condensate is R can be charged to the desired voltage level, independently of the other.

In real devices rarely provide dvukhmonitornye layout. Data layout have imperfections such as large size and cost. Therefore, in an external defibrillators typically use only a capacitor to reduce cost and size. When using a single capacitor for forming a two-phase waves, to switch waves use the so-called H-bridge. During the first wave phase H-bridge connects the two output capacitor to the electrodes. At the end of the first phase, the connection is terminated, and the terminals of the capacitor switch for connection in reverse polarity to the electrodes. Since this time, often switching currents, between pauses often there is a pause, represented by the interval G time in Fig.2a. Because it uses only one capacitor, the voltage on the capacitor at the end of the first phase is the initial voltage at the beginning of the second phase, when switches a connection of the capacitor. As shown in Fig.2a, the above condition will mean that V2= -V1.

In Fig.2a shows other wave parameters that are important for efficiency. One parameter is the relative duration of the phases, i.e., the ratio of the length E of the first phase to the length F of the second phase.Given the attitude of the times, which is often used is 60-40%. That is, it is desirable that the total duration of the wave is the first phase took 60% of the time, and the second phase took 40% of the time. The total duration of the wave (E+G+F) is also of great importance. It is desirable that the duration of the wave was large enough for defibrillation of the patient, but also short enough not to cause electrical lesion of the patient. In other words, it is desirable only to attach the shock to the patient during the time necessary to ensure defibrillation; and should be deleted continuous supply of energy, which does not increase the effectiveness of defibrillation. Usually use two-phase wave with an overall length in the range of 5-20 milliseconds.

Another parameter of the wave, which has a greater value is the parameter, which is known as the "relative decline of the peak impulse" ("tilt") of the wave. The relative decline of the peak of the pulse is a measure of power and is expressed as a percentage of initial and final stress waves. The equation for calculating the relative decline of the peak of the pulse has the form:

,

where V0is the initial voltage wave (the amplitude of A wave), and V3is the final voltage wave (the amplitude of the D wave) Fig.2a. Rel the relative decline of the peak of the pulse can also be calculated for each phase waves separately.

In Fig.2a shows the wave, known as a wave with a small relative decline of the peak of the pulse. Waves with a small relative decline of the peak of the pulse is typically arise when applying the pulse wave in patients with high thoracic impedance. Considering the fact that the voltage, current and impedance of the patient are related by Ohm's law, the high impedance of the patient during this initial voltage V0pulse will lead to a relatively weak current, and the voltage reduction for the duration of the pulse will be relatively small. In Fig.2a shows a relatively small decrease in voltage during the first phase 72 wave 70 from V0to V1and during the second phase 74 from V2to V3.

In Fig.2b shows the wave with a large relative decline of the peak of the pulse, usually arising in the case of a patient with a low impedance. The low impedance of the patient's current more with this voltage, and the voltage reduction during the submission of the wave is larger than the decrease in the voltage wave with a small relative decline of the peak of the pulse, shown in Fig.2a. With the same initial voltage V0the wave in the first phase 72 is reduced to V1(the amplitude of the B wave is lower than in the case of waves with a small relative decline of the peak of the pulse, shown in Fig.2a. Similarly, is the greater the reduction from V 2(the amplitude of the C wave) to a final voltage V3during the second phase 74.

Conclusion the characterization of the relative decline of the peak of the pulse is that wave with a large relative decline in the top of the pulse will decrease to a specified end voltage in less time than wave with a small relative decline of the top pulse to the same final voltage. This means that a wave with a small relative decline of the peak of the pulse can last for a considerable, perhaps excessive period of time to achieve the same final voltage. Since it is assumed that defibrillation is usually during the initial few milliseconds of the first phase, when the supplied current is strongest, it is possible for only the first 7 milliseconds, when the average current is maximum, most of the time a long wave with a small relative decline of the peak of the pulse can be therapeutically ineffective and, therefore, not mandatory. One known solution to this problem is to reduce the second phase 74 wave 70, as shown in Fig.3. The first phase 72 will begin with your starting level V0voltage and to last for some pre-programmed or adaptiva the Noi to the impedance of the length E or until until it reaches the set voltage V1. The second phase 74 begins with its initial voltage V2as before, but terminated prematurely or shortened in time F'. The length F' of the second phase can only be set for the second phase or maintaining a maximum total duration (E+F'). For example, the second phase 74 waves can be shortened, when F' is equal to E, and the ratio of the duration of the phases is 50:50.

The problem with shortening the second phase consists in the fact that the second phase finishes applied pulse at a considerable voltage is still supplied to the myocardium at the end of the wave. The final voltage V3shown on Fig.3, higher than the end voltage if the second phase was allowed to decline further. Mentioned significant end voltage can have a detrimental effect on the effectiveness of therapy. Theoretically, it is desirable that the final voltage defibrillation wave was zero, so that, after the pulse, on myocardial cells did not remain any residual charge, which could have a detrimental effect on offline restart in the body electric pulsations of the heart. Such removal of the residual charge is referred to as a specialist "burping". See U.S. patent 5991658 (Brewer and others). Another advantage of the cessation of defibrillation the wave on a smaller voltage is what this minimizes the sensitivity of the calculation of the optimal dose of the second phase to the uncertainty characteristics of cellular responses, individual, when applied to a specific patient. The third advantage of the termination defibrillation waves at almost zero voltage is to exclude the phenomenon of "destructive excitation", i.e. stimulation of the after-shocks of arrhythmia shock caused by a large change in the voltage. One way to achieve these goals is to provide opportunities for full decay phases of the biphasic pulse to zero volts, as shown in U.S. patent 6539255 (Brewer and others). The feasibility of this approach can be understood from consideration of Fig.4a-4c, which shows the two-phase wave 80, together with which conducted the characteristics of 90 reactions myocardial cells. As mentioned above, the reaction of the myocardial cells may vary from patient to patient and even from day to day and, in General, not known for this patient at the time of salvation. In Fig.4a shows in real time the response of the myocardial cells in the ideal case. Change reaction characteristics of myocardial cells can be characterized by a constant εTtime of the cell membrane, which nominally is 3.5 milliseconds. In the case shown in Fig.4a, this time constant duration which provides rise characteristics 90 reaction myocardial cells during the first phase 82 biphasic wave 80, until it reaches a maximum at the end of the first phase. When a wave pulse is switched to the second phase 84, characteristic reactions of myocardial cells is reduced, as shown in the last section 94 of the reaction characteristics. In this case, at the end of the second phase 84, characteristic reactions fell exactly to its original starting level. This decrease indicates that the cell membranes of myocardial there is no residual charge at the end of the pulse 80.

In Fig.4b shows a situation in which the characteristic 90 reaction myocardial cells has a smaller constant εTtime of the cell membrane, which leads to the achievement of the characteristic reactions of its maximum before the end of the first phase of 82 two-phase pulse 80. Then the characteristic reaction decreases together with the decrease in the relative decline of the peaks of the pulse wave, i.e., there is a reaction, which, as I believe, gives a very small contribution to the defibrillation. During the second phase 84 two-phase pulse characteristic reaction continues even faster to change, with a decrease below its initial level and the following decrease in the relative decline of the top pulse of the second phase while the second phase 84 of the pulse will not end. As can be seen in the figure, when the characteristic of the reaction is below its initial level, and thus while the displays, on the membranes of myocardial cells remains some residual charge. This situation represents a case, which can occur with a patient with a low impedance.

In Fig.4c shows the situation for a patient with a high impedance, when the characteristic 90 reaction myocardial cells increases very slowly, as indicated by the position 92, during the first phase 82 biphasic wave 80. Characteristic reactions still increases at the moment when the first phase ends 82. When is the second phase 84 of the pulse, the characteristic reaction begins a gradual decline, but not quite reaches its original starting level at the end of the second phase. This characteristic also indicates the presence of residual charge on the cell membranes of the myocardium.

In accordance with the principles of the present invention to eliminate the above conditions proposed scheme 100 of the defibrillator shown in Fig.5. In this scheme the energy to supply two-phase pulse is accumulated in a single capacitor 102. In preparation for the filing of the pulse, the battery or power supply circuits 20 power management is connected to the high voltage circuits 16. Switches Sc1and Sc2closed and the high voltage circuit 16 to charge the capacitor 102 to the level of V0high voltage of 2000 volts. When cond is Nestor 102 is fully charged to the desired level, switches Sc1and Sc2the current path. Then the diagram H-bridge containing the switches S1, S2, S3and S4switches for leading biphasic pulse to the patient P via the electrodes 104 and 106. During the first phase of the biphasic pulse, the switches S1and S2closed, and the capacitor is connected to the electrodes of the patient for current flow through the patient in one direction, for example, from electrode 104 on the chest to the electrode 106 on the chest. A small resistance 110, for example, 10 Ohms, limits the maximum current to prevent damage to the patient with low impedance. At the end of the first phase, the switches S1and S2open to the termination of the first phase of the biphasic pulse, and the switches S3and S4close to summarize the two-phase pulse to the patient P. the Closure of these switches causes current from the capacitor 102 flows in the opposite direction in the first phase, in this example, from electrode 106 on the chest to the electrode 104 on the chest. In the current path of the second phase is also possible to successively enable small resistance 112, 10 Ohms, for example. In accordance with the principles of the present invention, the switch S1also closed for a period of lying is neither the second phase of the pulse. In a preferred embodiment, the switch S1 is switched between closed and open positions during the second phase by controlling the switch based on the pulse-width modulation. The closure of switch S1provides course some part of the capacitor 102, bypassing the patient P along the path created by the switches S1and S4when the switch S1closed during the second phase. As a result, the voltage of the capacitor 102 is reduced faster than it is decreased if the switch S1was not applied during the second phase. The obtained result with the two-phase wave shown in Fig.6, which shows a steep decrease (greater relative decline of the peak of the pulse) of the second phase 86 biphasic pulse. Using the control circuit of the switch S1the second phase 86 two-phase pulse can be increased almost to the reference potential at the end of the two-phase waves and in less time than if the switch S1not used during the second phase. Through this operation, the target voltage V3at the end of the two-phase pulse is brought almost to zero.

Impedance measurement interface, which can be performed using a bandwidth small signal before applying the shock, as described in article Cerberus with SOA is tori (Kerber and others), or measuring the applied current or applied voltage during the actual submission of high-voltage pulses, as shown in the aforementioned U.S. patent inventors FEIN with co-authors (Fain and others), Cameron and co-authors (Cameron and others) and Gliner with co-authors (Gliner and others), can be used to control parameters of the supplied shock waves, for example, energy, charge voltage of the capacitor and the duration of the waves, as explained in the aforementioned patents and in U.S. patent 5352239 (Pless).

The result mentioned controlled lowering or relative decline of the top pulse of the second phase of the biphasic pulse is that it is possible to ensure that the pulse wave ended near its reference potential. This result reflected the three characteristics reaction to myocardial cells, held in conjunction with the wave biphasic pulse, Fig.6. In the case when there is exact agreement of two-phase pulse with the cellular response, as reflected by the characteristic 120 reaction myocardial cells, characterization of the reaction increases to almost the leaf nodes of the first phase 82 biphasic pulse, then decreases during the second phase 86, as reflected by section 123 of the characteristics of the reaction, as long as the characteristic is not the end near the end of level V3voltage. For patients who NTA with low impedance, as reflected characteristic of 130 reaction, characteristic reactions again rising rapidly during the first phase 82, as reflected by curve 131, and also reduced during the second phase 86 two-phase pulse before the end near the end of level V3voltage. For patients with high initial impedance plot characteristics 140 141 reaction increases during the first phase 82, then decreases to almost the end of level V3voltage. The discrepancy between the endpoints of all of the characteristics of the reaction myocardial cells, as shown in Fig.6, it is very small, in contrast to the differences shown in Fig.4a-4c, and thus shows that in all cases in cell membranes remains a slight residual charge. The voltage wave ends near zero, regardless of the impedance of the patient. This result is achieved by the defibrillator regardless of the absence of any a priori information regarding the characteristics of the reaction myocardial cells.

In the preferred embodiment, as mentioned above, constant relative decline of the top pulse of the second phase of the biphasic pulse manageable increases or is controlled by switching of the switch S1between open and closed States during the filing of the second phase of dwuhfaznosti. This control switch based on the pulse width modulation can be performed while controlling the voltage of the capacitor 102. You can also use other methods of control switch, for example, the closure of switch S1during one interval of predetermined duration. In a preferred embodiment, the capacitor 102 is applied to the capacitor 200 microfarad. The present invention can be implemented using a defibrillator with a single capacitor or a defibrillator with multiple capacitors, in which during the two phases of the supplied wave using different capacitor or combination of capacitors. In the preferred embodiment, is controlled by the relative decline of the top pulse of the second phase to save approximately 95% of the total relative decline of the peak of the pulse. The increase in the relative decline of the peak of the pulse during the second phase also provides the benefit of creating opportunities for effective therapeutic effects with the application of a reduced range of duration of the waves, while the preferred implementation generates waves biphasic pulses in the range of 6.5 milliseconds to 12 milliseconds for the whole population of impedance the patients ie provides a significant reduction relative to the normal maximum duration of the pulse, representing 20 milliseconds.

1. External defibrillator, which delivers two-phase defibrillation pulses, these defibrillator contains:
high-voltage circuit;
a capacitor connected to a high voltage circuit that charges the high-voltage circuit for supplying defibrillating impulse;
a pair of electrodes of the patient;
many switches containing H-bridge connected between the capacitor and the electrodes of the patient and configured to connect the first and second phases of the biphasic wave defibrillating pulse to the electrodes of the patient, and the relative decline of the top pulse of the second phase of the wave is manageable adjustable; and
a controlled current path, which includes the switch H-bridge, and which provides a managed bypass current electrodes of the patient during the second phase of the biphasic wave.

2. External defibrillator under item 1,
where multiple switches contains a H-bridge with a single configuration circuit switches to supply one phase two phase waves and a different configuration of the circuit switches to supply the opposite phase of the biphasic wave.

3. External defibrillator under item 1,
in the cat the rum capacitor contains one container, which is used to supply both phases of the biphasic wave.

4. External defibrillator under item 1,
in which the capacitor further comprises a first capacitor, which is used to supply the first phase of the biphasic waveform, and a second capacitor, which is used to supply the second phase of the biphasic wave.

5. External defibrillator under item 1,
in which H-bridge further comprises first and second switches, which are closed to pulse during the first phase of the biphasic waveform, and the third and fourth switches, which are closed to pulse during the second phase of the biphasic wave,
this controlled current path contains one of the first and second switches.

6. External defibrillator under item 5,
optionally containing a first resistor connected in series with the first and second switches when the first and second switches are closed, and a second resistor connected in series with the third and fourth switches when the third and fourth switches are closed.

7. External defibrillator under item 1,
where management controlled by the output control signal with pulse-width modulation during the second phase of the biphasic wave.

8. External defibrillator under item 1,
in which wave two-phase defibrillation pulse is and has:
the first phase, during which the voltage pulse rises from the reference potential to the maximum voltage V0and decreases from V0during the first phase of the waves; and
the second phase, which begins with an initial voltage V2and goes with the reduction from V2during the second phase of the wave to a level equal to or almost equal to the reference potential.

9. External defibrillator under item 8,
in which voltage V0and V2opposite in sign relative to the reference potential.

10. External defibrillator under item 1,
additionally contains the schema made with the possibility of measuring the impedance of the patient,
the parameters of the biphasic wave defibrillating pulse is set in accordance with the measured impedance of the patient.

11. External defibrillator under item 1,
in which the overall relative decline of the vertices of the two-phase pulse wave is aged about 95% by controlling the relative decline of the top pulse of the second phase of the wave.

12. External defibrillator on p. 11,
in which the overall relative decline of the vertices of the two-phase pulse wave is aged about 95% by increasing the relative decline of the top pulse of the second phase of the wave.



 

Same patents:

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, in particular, to systems of ECG monitoring, which trace indications of ciliary arrhythmia (CA) in real time. System of ciliary arrhythmia monitoring contains source of electrocardiogram data, extractor of P-wave signs, extractor of interval R-R signs, CA classifier, reacting to P-wave sign and interval R-R sign, which classifies cardiac rhythm as that with CA or without CA, display, reacting to CA classifier for displaying CA classification, and user's input for regulation of balance sensitivity/specificity of identification of rhythm with CA, with user's input additionally containing selection of type of patient population for automatic adjustment of nominal working parameters of identification of rhythm with CA for selected type of patient population.

EFFECT: invention will make it possible to simplify adjustment of nominal working parameters Of CA monitoring system for selected type of patient population.

14 cl, 11 dwg

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to system for carrying out CPR. Device of providing feedback in carrying out CPR contains sensor of compression, adapted for placement between rescuer's hands and victim's chest, module of control with feedback, connected with compression sensor, and programmed for registration of output data of compression, their analysis, identification of single compression cycles and comparison of single cycles of compression with multitude of evaluation criterions. Matrix of comparison is output on presentation device, and each element of matrix corresponds to comparison of one of single compression cycles with one of multitude of evaluation criteria. Method of feedback presentation includes stages of carrying out compression of victim's chest through sensor of compression, registration, analysis, identification and comparison of output data from compression sensor with multitude of evaluation in form of comparison matrix elements.

EFFECT: invention makes it possible to increase efficiency of improvement of technical methods in carrying out CPR.

19 cl, 6 dwg

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to apparatuses for emergency medical care. The apparatus comprises a piece of clothing, a control unit arranged thereon used to control at least one physiological function of the patient to state an emergency, and a therapeutic device arranged on the piece of clothing and operatively connected to the control unit for treating the patient. The therapeutic device is a respiratory therapeutic device applied to supply oxygen, an oxygen-containing gas mixture and/or at least one drug endotracheally, and comprises a perforating unit to perforate the patient's trachea below the larynx.

EFFECT: use of the invention provides extending the range of apparatuses for emergency medical care.

20 cl, 2 dwg

FIELD: electricity.

SUBSTANCE: bipolar signal shaping device includes electric energy accumulator, controlled electronic switches switching it and control diagram of the above switches. For shaping of positive and negative polarity signal the electric energy accumulator which is connected to circuit of in-series connected switches is installed. Each of switches is parallel connected to resistor. Control circuit of switches for changing the pulse shape controls the activation of electronic switches and circuit for shaping of bipolar signal. Bipolar signal shaping circuit consists of four switches in-series connected to electric energy accumulator and pulse shape change circuit so that when the first and the fourth switches close, current flows through load in the direction shaping positive polarity signal and when the second and the third switches close, current flows through load in the direction shaping negative polarity signal. Control signals of electronic switches are supplied from control diagram for shaping of bipolar signal.

EFFECT: simplifying and optimising electric circuit.

3 dwg

FIELD: medicine.

SUBSTANCE: group of inventions refers to medical engineering and is designed to restore normal rhythm and contractile function of heart. Automatic external defibrillator includes a pair of electrode plates; a controller connected to the electrode plates through the front-end circuit of ECG and running for analysis of ECG signals to determine whether ECT is recommended, high-voltage circuit connected to the electrode plates for carrying out biphasic defibrillation electric shock when ECT/treatment protocol storage device is recommended, which retains one or more of treatment protocols that include the protocol of single electroshock controlled by AED for carrying out a single biphasic electric defibrillation, followed by a period of cardio-pulmonary resuscitation (CPR); while the controller is connected to the treatment protocol storage device working to implement the protocol of single electric shock where the single electric shock protocol is the default protocol for AED. The second version of defibrillator also contains a battery connected to AED power circuit; user interface control elements the administrator works with to select either a single electric shock protocol, or protocol of repeated electric shocks through the resident piece of software in AED, without removal of battery or linking-up external hardware or software to the AED.

EFFECT: providing opportunities of time management of cardio-pulmonary resuscitation.

14 cl, 10 dwg

FIELD: physics.

SUBSTANCE: invention can be used for generating powerful bipolar and multiphase electric pulses. The method involves controlling series-connected single-type power cells containing electrical energy accumulators, and providing switching of positive and negative polarity of the connection of the energy accumulator to leads of the cell, and switching the electrical energy accumulator to leads of the cell, and having bypass diodes which provide flow of current through leads of the cell when electrical energy accumulators are disconnected from the leads of the cell. A signal from a current sensor is transmitted to the analogue input of a digital signal processor (DSP), from the digital outputs of which the power cells are controlled. Before completion of generation of a pulse, the digital signal processor periodically converts the signal from the current sensor, standardises it, calculates deviation from the current value stores in the digital signal processor of the pulse form and compares the deviation with four limiting values. Signals for controlling power cells are output from the outputs of the digital signal processor depending on the comparison results.

EFFECT: simplification of the method of generating pulses and reducing the number of circuit components.

7 dwg, 1 tbl

FIELD: medicine.

SUBSTANCE: invention concerns medicine area, namely to area of urgent cardiological resuscitation. The heart defibrillator for treatment of the patient in case of cardiovascular activity termination by means of the shock blow provided with the dosed out diphasic electric discharge of high-voltage condenser through the H-shaped bridge circuitry, contains the high voltage commutator A, B, C or D in each of the branches. According to the invention each of opposite polarity phases of a diphasic shock blow is managed in two stages on time in such a manner that for each pair of the commutators concerning the given phase, the first of pair commutators is changed over in leading state and remains leading during all this phase whereas the second commutator of this pair is shorted with some time delay in relation to the first commutator throughout some operated duration for establishment of a current flow through a body of the patient during this phase, and the second phase is processed in the same way by means of other pair of commutators.

EFFECT: wide use of the defibrillation device.

13 cl, 6 dwg

FIELD: medical engineering.

SUBSTANCE: device has means for producing defibrillation pulse having electric current source, capacitive electric energy storage, high voltage commutator, control unit and control system having patient electrophysical parameter control means and high voltage pulses control means and at least two therapeutic electrodes. The device also has means for compressing human body chest manufactured for instance as elastic cuff having a built-in ultrasonic radiator.

EFFECT: high reliability in delivering defibrillation pulse at given address.

5 cl, 1 dwg

FIELD: medicine.

SUBSTANCE: method involves creating therapeutic circuit fixed on patient body, at least two working therapeutic electrodes, measuring and analyzing patient-dependent electrophysical parameters, charging capacitive storage and its later discharging to the working therapeutic electrodes controlled with control unit. Transmitting defibrillation impulse of given power in discharging is carried out in dosed manner first with the first portion W1 of given power dose with the second portion W2 being accumulated on inductive defibrillation power accumulator and then with the second portion W2 of given power dose. Ratio of the first portion W1 of given power dose to the second portion W2 of given power dose of defibrillation impulse is selected from the range of 0.01 to 150. Defibrillation impulse current intensity is selected only when emitting the first portion W1 of given power dose. Cardiodefibrillation impulse is built as bipolar Gurvich impulse. The given power quantity usable for charging the capacitive defibrillator storage is selected to be equal to a value from the range of 4-500 J, defibrillation impulse current intensity being selected from the range of 0.005 to 175 A and voltage equal to a value from 3 to 30000 V. Means has power supply source having unit for controlling charge level of the capacitive storage, unit for building defibrillation pulses, switchboards formed by controlled keys, at least two working therapeutic electrodes and diodes bypassing the controlled keys, resistive current transducer, analog-to-digital converter and control unit having required functional communications to the analog-to-digital converter and controlled keys. The resistive current transducer is in current feeding bus having minimum potential relative to measuring unit under operation having analog-to-digital converter in its structure.

EFFECT: enhanced effectiveness of usage; high safety of patient treatment procedure.

7 cl, 9 dwg

The invention relates to a device of a charging capacitor

FIELD: medicine.

SUBSTANCE: method involves creating therapeutic circuit fixed on patient body, at least two working therapeutic electrodes, measuring and analyzing patient-dependent electrophysical parameters, charging capacitive storage and its later discharging to the working therapeutic electrodes controlled with control unit. Transmitting defibrillation impulse of given power in discharging is carried out in dosed manner first with the first portion W1 of given power dose with the second portion W2 being accumulated on inductive defibrillation power accumulator and then with the second portion W2 of given power dose. Ratio of the first portion W1 of given power dose to the second portion W2 of given power dose of defibrillation impulse is selected from the range of 0.01 to 150. Defibrillation impulse current intensity is selected only when emitting the first portion W1 of given power dose. Cardiodefibrillation impulse is built as bipolar Gurvich impulse. The given power quantity usable for charging the capacitive defibrillator storage is selected to be equal to a value from the range of 4-500 J, defibrillation impulse current intensity being selected from the range of 0.005 to 175 A and voltage equal to a value from 3 to 30000 V. Means has power supply source having unit for controlling charge level of the capacitive storage, unit for building defibrillation pulses, switchboards formed by controlled keys, at least two working therapeutic electrodes and diodes bypassing the controlled keys, resistive current transducer, analog-to-digital converter and control unit having required functional communications to the analog-to-digital converter and controlled keys. The resistive current transducer is in current feeding bus having minimum potential relative to measuring unit under operation having analog-to-digital converter in its structure.

EFFECT: enhanced effectiveness of usage; high safety of patient treatment procedure.

7 cl, 9 dwg

FIELD: medical engineering.

SUBSTANCE: device has means for producing defibrillation pulse having electric current source, capacitive electric energy storage, high voltage commutator, control unit and control system having patient electrophysical parameter control means and high voltage pulses control means and at least two therapeutic electrodes. The device also has means for compressing human body chest manufactured for instance as elastic cuff having a built-in ultrasonic radiator.

EFFECT: high reliability in delivering defibrillation pulse at given address.

5 cl, 1 dwg

FIELD: medicine.

SUBSTANCE: invention concerns medicine area, namely to area of urgent cardiological resuscitation. The heart defibrillator for treatment of the patient in case of cardiovascular activity termination by means of the shock blow provided with the dosed out diphasic electric discharge of high-voltage condenser through the H-shaped bridge circuitry, contains the high voltage commutator A, B, C or D in each of the branches. According to the invention each of opposite polarity phases of a diphasic shock blow is managed in two stages on time in such a manner that for each pair of the commutators concerning the given phase, the first of pair commutators is changed over in leading state and remains leading during all this phase whereas the second commutator of this pair is shorted with some time delay in relation to the first commutator throughout some operated duration for establishment of a current flow through a body of the patient during this phase, and the second phase is processed in the same way by means of other pair of commutators.

EFFECT: wide use of the defibrillation device.

13 cl, 6 dwg

FIELD: physics.

SUBSTANCE: invention can be used for generating powerful bipolar and multiphase electric pulses. The method involves controlling series-connected single-type power cells containing electrical energy accumulators, and providing switching of positive and negative polarity of the connection of the energy accumulator to leads of the cell, and switching the electrical energy accumulator to leads of the cell, and having bypass diodes which provide flow of current through leads of the cell when electrical energy accumulators are disconnected from the leads of the cell. A signal from a current sensor is transmitted to the analogue input of a digital signal processor (DSP), from the digital outputs of which the power cells are controlled. Before completion of generation of a pulse, the digital signal processor periodically converts the signal from the current sensor, standardises it, calculates deviation from the current value stores in the digital signal processor of the pulse form and compares the deviation with four limiting values. Signals for controlling power cells are output from the outputs of the digital signal processor depending on the comparison results.

EFFECT: simplification of the method of generating pulses and reducing the number of circuit components.

7 dwg, 1 tbl

FIELD: medicine.

SUBSTANCE: group of inventions refers to medical engineering and is designed to restore normal rhythm and contractile function of heart. Automatic external defibrillator includes a pair of electrode plates; a controller connected to the electrode plates through the front-end circuit of ECG and running for analysis of ECG signals to determine whether ECT is recommended, high-voltage circuit connected to the electrode plates for carrying out biphasic defibrillation electric shock when ECT/treatment protocol storage device is recommended, which retains one or more of treatment protocols that include the protocol of single electroshock controlled by AED for carrying out a single biphasic electric defibrillation, followed by a period of cardio-pulmonary resuscitation (CPR); while the controller is connected to the treatment protocol storage device working to implement the protocol of single electric shock where the single electric shock protocol is the default protocol for AED. The second version of defibrillator also contains a battery connected to AED power circuit; user interface control elements the administrator works with to select either a single electric shock protocol, or protocol of repeated electric shocks through the resident piece of software in AED, without removal of battery or linking-up external hardware or software to the AED.

EFFECT: providing opportunities of time management of cardio-pulmonary resuscitation.

14 cl, 10 dwg

FIELD: electricity.

SUBSTANCE: bipolar signal shaping device includes electric energy accumulator, controlled electronic switches switching it and control diagram of the above switches. For shaping of positive and negative polarity signal the electric energy accumulator which is connected to circuit of in-series connected switches is installed. Each of switches is parallel connected to resistor. Control circuit of switches for changing the pulse shape controls the activation of electronic switches and circuit for shaping of bipolar signal. Bipolar signal shaping circuit consists of four switches in-series connected to electric energy accumulator and pulse shape change circuit so that when the first and the fourth switches close, current flows through load in the direction shaping positive polarity signal and when the second and the third switches close, current flows through load in the direction shaping negative polarity signal. Control signals of electronic switches are supplied from control diagram for shaping of bipolar signal.

EFFECT: simplifying and optimising electric circuit.

3 dwg

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to apparatuses for emergency medical care. The apparatus comprises a piece of clothing, a control unit arranged thereon used to control at least one physiological function of the patient to state an emergency, and a therapeutic device arranged on the piece of clothing and operatively connected to the control unit for treating the patient. The therapeutic device is a respiratory therapeutic device applied to supply oxygen, an oxygen-containing gas mixture and/or at least one drug endotracheally, and comprises a perforating unit to perforate the patient's trachea below the larynx.

EFFECT: use of the invention provides extending the range of apparatuses for emergency medical care.

20 cl, 2 dwg

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to system for carrying out CPR. Device of providing feedback in carrying out CPR contains sensor of compression, adapted for placement between rescuer's hands and victim's chest, module of control with feedback, connected with compression sensor, and programmed for registration of output data of compression, their analysis, identification of single compression cycles and comparison of single cycles of compression with multitude of evaluation criterions. Matrix of comparison is output on presentation device, and each element of matrix corresponds to comparison of one of single compression cycles with one of multitude of evaluation criteria. Method of feedback presentation includes stages of carrying out compression of victim's chest through sensor of compression, registration, analysis, identification and comparison of output data from compression sensor with multitude of evaluation in form of comparison matrix elements.

EFFECT: invention makes it possible to increase efficiency of improvement of technical methods in carrying out CPR.

19 cl, 6 dwg

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, in particular, to systems of ECG monitoring, which trace indications of ciliary arrhythmia (CA) in real time. System of ciliary arrhythmia monitoring contains source of electrocardiogram data, extractor of P-wave signs, extractor of interval R-R signs, CA classifier, reacting to P-wave sign and interval R-R sign, which classifies cardiac rhythm as that with CA or without CA, display, reacting to CA classifier for displaying CA classification, and user's input for regulation of balance sensitivity/specificity of identification of rhythm with CA, with user's input additionally containing selection of type of patient population for automatic adjustment of nominal working parameters of identification of rhythm with CA for selected type of patient population.

EFFECT: invention will make it possible to simplify adjustment of nominal working parameters Of CA monitoring system for selected type of patient population.

14 cl, 11 dwg

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment. An external defibrillator for two-phase defibrillation waveform supply comprises a high-voltage circuit, which accommodates a condenser, as well as a pair of electrodes and a number of switches. The high-voltage circuit is presented to charge the condenser to supply the defibrillation pulse. The switches comprise an H-bridge, connected between the condenser and electrodes and can be connected to first and second phases of the two-phase defibrillation waveform to the electrodes. A second-phase tilt is adjustable. The controlled conduction path comprises the H-bridge switch and enables the controlled conduction path for the second phase of the two-phase waveform.

EFFECT: using the invention enables higher safety and effectiveness of defibrillation.

12 cl, 6 dwg

Up!