RU187884U1 - Neurostimulation apparatus - Google Patents

Abstract

The utility model relates to medicine, namely to devices (device) of regional conduction anesthesia for neurostimulators designed to block peripheral nerve bundles and fibers in order to perform local anesthesia during operations. Structurally, the closest analogue is an electric neurostimulator (Patent for invention N RF 2 107 459 A61B5 / 05), designed to search and stimulate nerves and nerve plexuses with electrical signals. The known device contains a master oscillator, a pulse width generation circuit, a gain stage and an output stage. Adjusting elements in the form of variable resistors are introduced into the master oscillator and the pulse duration generation circuit. The purpose of this utility model is to create a device with known characteristics of neurostimulation devices with the ability to control the current, frequency and duration of pulses and having an indication of the passage of current through the body, lower manufacturing costs, made on the basis of domestic radio electronics. A useful model contains five main components: a master oscillator square wave, pulse shaper unit, output amplifier, indication unit, power supply. A feature of the claimed utility model is that as an indication of the passage of the current pulse through the body, an LED is used that flashes in time with the incoming pulse only if the current flows through the patient's body thanks to the current sensor implemented on VTZ. Therefore, in case of breakage or insufficient contact of the electrodes with the patient’s body, such a visualization of the process will help to avoid unnecessary trauma to the needle with the electrode and the doctor’s mistakes during the procedure. The search for a nerve as the nerve trunk is localized is carried out by focusing on the strength of the muscle response and lowering the pulse current to the level of 0.5-0.2 mA, which allows the nerve to be localized in very precise limits of 1-2 mm. The claimed utility model can be implemented on an elemental base of domestic electronics and has a significantly lower cost of manufacture with the same characteristics.

Description

The utility model relates to medical equipment, namely to devices for performing regional conduction anesthesia of nerves, nerve trunks and plexuses. The neurostimulation apparatus (device) is designed to search, localize and block nerves in order to anesthetize the areas of interest during surgical interventions.

Conduction anesthesia is one of the types of anesthesia, the purpose of which is to block the transmission of nerve impulses in the body area where surgery is planned. As a result of such anesthesia, complete patient immobilization and analgesia are achieved. During anesthesia, it is precisely the nerve that selects the impulse from the operated area. Anesthesia during conduction anesthesia is achieved due to blockade of a nerve or a group of nerves (a group of nerves), through which a pain impulse is transmitted from the source of pain (surgery site) to the brain, in which this impulse is converted into a pain sensation. For safer and more efficient conduction anesthesia use special devices - neurostimulators. They make it possible to determine the exact location of the needle relative to the nerve that needs to be blocked. Thus, conduction anesthesia is a reversible blockade of the transmission of a nerve impulse along the nerve trunk (nerve, plexus, node) by the introduction of a local anesthetic solution in the immediate vicinity of the nerve trunk, which is performed before surgery or to eliminate pain. Electrical neurostimulation is a method of searching for nerves before administering a local anesthetic (novocaine, lidocaine, ropivacaine, etc.).

When peripheral nerves are blocked, the localization of a nerve or nerve plexus is determined by muscle contraction or pain in response to stimulation with short rectangular pulses of electric current of small amplitude and a given frequency. The purpose of this procedure is to administer the anesthetic as close to the nerve trunk as possible to block the sensory and motor fibers before surgery or to eliminate pain. Electrical neurostimulation also avoids the introduction of anesthetic directly into the nerve or its sheath, thereby preventing damage to the nerve. For a safe and effective search for nerves and nerve plexuses and conductive anesthesia, special devices are used - neurostimulators.

Neurostimulants provide the doctor with the opportunity to determine the exact location of the needle relative to the nerve, which is supposed to be blocked, after determining which is injected with the desired drug (anesthetic). Thus, with the help of a neurostimulator, fast, accurate and effective anesthesia of a narrow necessary part of the body is provided.

A similar device is known neurostimulator Stimuplex HNS 12 company B. Braun. The disadvantage of this device is its high price. The closest analogue is an electric neurostimulator (Patent for invention N RF 2107459 АВВ 5/05) designed to search and stimulate nerves and nerve plexuses by electrical signals. The known device contains a master oscillator, a pulse width generation circuit, a gain stage and an output stage. Adjusting elements in the form of variable resistors are introduced into the master oscillator and the pulse duration generation circuit.

The purpose of this utility model is to create a device with known characteristics of neurostimulation devices with the ability to control the current, frequency and duration of pulses and having an indication of the passage of current through the body, lower cost of manufacturing made on the basis of domestic radio electronics. The approximate cost of such a device according to the authors is less than three thousand rubles, which is more than forty times less than foreign analogues.

The appearance of a useful model of a neurostimulation apparatus in operation is shown in FIG. 1. A block diagram of a neurostimulation apparatus is shown in FIG. 2. A circuit diagram of a neurostimulation apparatus is shown in FIG. 3. The claimed solution is industrially applicable, implemented, used in practical work, which can be observed in FIG. four.

A brief description of the drawings.

FIG. one.

Appearance of a useful model of a neurostimulation apparatus

(1) - device, (2) - current scale, (3) - plug from the connecting wires used to connect the electrodes, (4) - toggle switch on the device; (5) - battery discharge indicator, (6) - LED signaling the passage of current pulses, (7) - potentiometer for regulating current pulses, (8) - connecting two-wire wire for connecting a stimulating needle electrode and Velcro electrode to the device - ( 9), the needle - (10), the syringe for injection - (11).

FIG. 2.

The utility model contains five main nodes indicated on the block diagram. Moreover, the “master oscillator” of rectangular oscillations provides the frequency mode of the stimulator and gives short-term pulses with a given frequency. The “pulse forming unit” provides the necessary pulse duration. The basis of this unit is a standby multivibrator that is triggered when each pulse arrives from it from the master oscillator. At the same time, pulse width adjustment is carried out independent of the frequency. The “output amplifier” provides the necessary pulse power and has a device for changing the current strength at the output to which the electrodes are connected directly. “Indication block” serves to visualize the passage of an impulse through the patient’s body. The “power supply” serves to power the circuits of the device. This device uses battery power from one element of the 6F22 Krona type with a voltage of 9V.

FIG. 3

Schematic diagram of the neurostimulation apparatus

On the logic elements DD1-1, DD2-1, DD2-2, CMOS chips, RC is implemented - a master oscillator that generates rectangular pulses of a given frequency. Elements R1, C1 determine the frequency of the pulses. The pulse duration is determined by a chain of series-connected elements C2 and R5. The VT3 transistor implements a simple voltage-current converter that allows you to hold the desired current value in a wide range of load resistance, the required voltage is supplied from the DC / DC converter made on mc1. The chain R10, R11 forms a stabilized voltage amplitude during the pulse. The variable resistor R13 is used to set, by the doctor, the required value of the pulse amplitude. On the elements VT4, VT5, DD1-3, DD1-4, DD1-6, HL1 and R16, an indication is implemented that signals the passage of a pulse by the flash of the LED HL1. The device contains a serially connected master oscillator, a pulse shaper, an amplifier and an LED display unit, while maintaining the required technical characteristics and functionality for a high-quality regional anesthesia procedure, is distinguished by its constructive simplicity of manufacture and low cost in comparison with foreign analogues. As an indication of the passage of a current pulse through the body, an LED is used that flashes in time with the incoming pulse only if the current flows through the patient's body thanks to the current sensor implemented on VT3. Therefore, in case of breakage or insufficient contact of the electrodes with the patient’s body, such a visualization of the process will help to avoid unnecessary trauma to the needle with the electrode and the doctor’s mistakes during the procedure.

On the elements DD1-3, DD1-4, a standby multivibrator is made, controlled by a master oscillator, the load of which is LED HL1. The power supply of the nodes and elements of the device is carried out by means of a five-volt integrated stabilizer MS2. On the transistors VT1, VT2 and the HL2 LED, a battery discharge indicator (optional) is implemented.

The amplitude of the output signals does not depend on the supply voltage, since the device uses a voltage converter that provides the desired supply voltage when the battery is discharged to 5 volts - in fact, until the element is completely discharged. The device is industrially applicable, manufactured and tested in practice.

The search for a nerve as the nerve trunk is localized is carried out by focusing on the strength of the muscle response and reducing the pulse current to the level of 0.5-0.2 mA, which allows the nerve to be localized in very precise limits of 1-2 mm.

FIG. four

The practical application of the neurostimulation apparatus in work is presented.

Claims (1)

 A neurostimulation device containing a serially connected driving pulse generator, a current pulse generating unit based on a standby multivibrator, and an LED display unit with LED, capable of flashing the LED to the beat with incoming pulses only if the current flows through the patient's body thanks to the current sensor.

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