CZ201268A3 - Electrode for percutaneous neurostimulating therapy - Google Patents

Abstract

BACKGROUND OF THE INVENTION The present invention relates to an electrode which, when positioned at a suitable location on the surface of the skin, electrically stimulates the underlying neural girdle beneath it. Advantageously, the electrode of the invention can treat the disease function of the lower urinary tract so as to prevent spontaneous urinary incontinence. The electrode comprises a pulse contact element (1) for adhering to the stimulated nerves, a core (4) which is conductively connected to the contact element (1), and a permanent magnet (3) in the form of a cylinder which is coaxially mounted on the core (4). ) and is oriented with its north pole to the pulse contact element (1). The stabilizing disc (6) and means (5) for attachment to the limb are threaded onto the core (4) between the permanent magnet (3) and the washer (8) and secured by a nut (7).

Description

Technical field

The invention relates to an electrode which, upon application to the skin, allows to electrically stimulate suitable neural girdles located in the undersized tissues. Preferably, the electrode is intended to stimulate nerves in the lower limbs in the treatment of the lower urinary tract disease function (urinary incontinence).

BACKGROUND OF THE INVENTION

The current treatment of urinary incontinence, which affects a significant part of the population, has not been completely therapeutically successful yet, despite its concomitant complications and social impacts. Pharmacological treatment prevails, accompanied by frequent side effects and a gradual decrease in efficacy. Surgical interventions in severe cases bring their intervention risks and possible subsequent urological problems.

The so-called Stoller electrostimulation method (Stoller, M .: Needle stimulation (through the skin) for the treatment of incontinence. Quality care 16: 1, 1998) brought a new treatment option. This method consists in introducing a sterile needle (or needle electrode) into close to the nerve of the tibialis nerve above the ankle of the foot Negative electric pulses of milliseconds and milliamper currents are delivered to the needle One exposure usually lasts for half an hour and the therapeutic effect is usually seen after 12 treatments.

However, the Stoller method, although only partially invasive, presents a number of application problems, possible side risks and, in particular, pain for the patient. The difficulty lies mainly in the need to inject a stimulating needle into the closest proximity of the tibialis nerve, the placement of which under the skin and muscle tissue may vary individually. Finding the effective position of the needle against the nerve often requires several preliminary, experimental punctures at each exposure with the risk of nerve impaling and damage. It is only possible to check the correct positioning of the needle to be inserted when a small distance from the nerve is reached according to the corresponding motor reflex on the toes. Repetition of punctures on loved ones or the same

* and · «· sites often lead to traumatic damage to penetrated tissues with the possibility of inflammation and necrosis. In practice, it has been shown that some patients have discontinued treatment for these painful aspects of progressing injuries to the injection sites.

US 5,370,671 describes an electrode for treating incontinence. It is a vaginal electrode for electrostimulation of pelvic floor muscles. For example, US 2004/0225343, GB 2 418 364 or WO 2006/053366 disclose electrodes of various types for medical use, namely the application of electrical signals to the skin.

The problems and drawbacks of the prior art are eliminated by the electrode described below for completely non-invasive percutaneous neurostimulatory treatment, in particular urinary incontinence treatment.

SUMMARY OF THE INVENTION

It was an object of the present invention to construct an electrode that is suitable for totally non-invasive electrical stimulation of nerves, particularly the lower limb nerves, with a therapeutic efficacy of at least that achieved using the invasive Stoller method. The object was achieved by constructing an electrode as described in more detail below, and a preferred embodiment thereof is shown in Example 1.

Research into the distribution of electromagnetic fields in human tissues around suitable nerve pathways for electrical stimulation by the present inventors has led to the development of an electrode with such a geometry that upon application to the skin allows the generation of an electric field of sufficiently large electrical gradient even at considerable depths of some tissues. Sufficient potential slope in the order of hundreds of millivolts is then able to activate the polarization of nerve cells and the formation of stimuli transmitted afferently to higher nerve centers. It follows from physical laws that the intensity of the electromagnetic field from the point electrode against the electrode of the infinite surface decreases with the square of the distance. From a physiological point of view, it is therefore not possible to increase the intensity of the electrical voltage at a point electrode applied to the skin surface in order to achieve polarization of cells of deeper nerve pathways at a distance of a few millimeters. The reason is the skin nerve receptors that would be close to the intense 11 1 f f f f f f 11 11 11 11 11 11 11 11

- 3 electric field electrodes have already emitted strong painful stimuli, and the current flow would release the thermal energy destroying adjacent tissue cells. By studying and conducting measurements of the conductivity properties of tissues around neural pathways suitable for afferent neurostimulation and subsequent neuromodulation, and by shaping the distribution of electric flux through a strong magnetic field of intensities of several hundred G (gauss) and variations in surface electrode geometry, a compromise and subcutaneous tissue layers so that they are not appreciably irritated even at a sufficient electrical current to stimulate deeper nerve pathways. Particularly suitable conditions have been found in the region of the lower and back of the thigh, and in particular in the knee of the well where the dividing branches of the nerve ischiadicus nerve take place. Based on these investigations, an electrode was designed and constructed to meet the requirement of totally non-invasive electrical stimulation with therapeutic efficacy equal to or greater than that of the Stoller method, without the need for painful and risky puncture of the puncture tissues. The high effectiveness of incontinence treatment using the electrode of the present invention has been confirmed by clinical trials. The treatment was without any side effects and discomfort to the treated persons.

The object of the invention was thus achieved by an electrode construction, which is further characterized in general terms and whose preferred embodiment is described in Example 1.

The subject of the invention is an electrode for use in percutaneous neurostimulatory treatment, particularly urinary incontinence treatment. The skilled artisan will appreciate that the electrode of the invention may be used for other types of electrical neurostimulatory therapy, e.g., for the treatment of pain.

The electrode comprises a hemispherical contact element, which is a portion of the electrode intended to contact the body surface above the stimulated nerves and to produce the desired distribution of the electromagnetic field of the tissue. The hemispherical contact element is by its base fixed by soldering to the electrode core in the form of a pin, the hemispherical contact element and the core being conductively connected. A cylindrical permanent magnet is coaxially mounted on the core. For proper functioning, ie the effect on the electric pulse field, this must be

I I ·

I t '»t · t ·» * I 4 41 liters and 1 liters and 1 liters. 4 a permanent magnet oriented north pole into the tissue. That is, the magnet is mounted so that it faces with its north pole toward the hemispherical contact element.

The term " hemispherical in the context " of the hemispherical contact element does not have a literal meaning to designate a body in the form of a perfectly accurate half sphere, but is also understood to include a smaller portion of the sphere. matching balls.

The hemispherical electrode contact element is made of biologically inert metals such as gold, titanium, silver, or alloys of these metals, preferably made of silver.

The electrode core is made of metal, preferably of stainless steel for surgical instruments.

The cylindrical permanent magnet is made of a highly magnetizable material, preferably an AlNiCo alloy. The magnet material must be capable of high magnetization and must not be subject to corrosion during washing and disinfection or sterilization of the electrode. A cylindrical permanent magnet suitable for the electrode of the invention exhibits a magnetic surface induction (i.e., intensity at the pole surface) of at least 300 G, preferably higher values, e.g. 400 G.

A ring-shaped washer is placed on the core, placed between the base of the half-contact element and the magnet. The pad prevents liquids (eg sweat) from entering the gap between the electrode and the magnet. The support is made of a biologically inert material, e.g., silicone or teflon, preferably teflon.

Said preferred materials are biocompatible and meet the standards for medical devices that need to be disinfected or sterilized. The skilled person is aware that there are a number of other suitable materials that can be used.

The electrode core may have a thread on the side opposite to the contact element, which allows the locking nut to be fitted, which together with the stabilizing disc can fix the electrode to a support means, e.g. a fastening strap. The end portion of the electrode core opposite the contact element is adapted to connect a «» «

to an electrical conductor, e.g., includes an adapter for fitting a conductor supplying an electrical signal from the electrostimulatory device.

The electrode of the invention may further comprise a stabilizing disc by means of which it can be stably attached to the means for attaching the electrode to the limb, preferably a fastening strap. The stabilizing wheel is made, for example, of polymethyl methacrylate, polycarbonate, PVC, PE or PET, preferably of a transparent material. The fastening strap, like the stabilizing disc, can be easily detached from the core. The strap is preferably elastic and can be made, for example, of textile or plastic fibers, or a combination thereof.

In the example, a preferred electrode for electrical stimulation of nerve girdles on the lower extremities in the treatment of urinary incontinence is described in detail. The skilled artisan will appreciate that the electrode may be modified in various ways without departing from the electrode defined in the appended claims.

Description of the picture

Giant. 1: Schematic of a neurostimulatory electrode comprising a hemispherical contact element, a core, and a permanent magnet. A. Cross section. B. Top view.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

A preferred embodiment of the electrode according to the invention is shown in Fig. 1. The hemispherical contact element 1 for contacting the electrode with the skin surface is conductively connected to the electrode core 4. The hemispherical contact element 1 is made of silver. The cylinder-shaped electrode core 4 is made of stainless steel. The connection of the half-sphere contact element 1 to the electrode core 4 is carried out by soldering with silver solder. The core 4 is threaded at the end opposite to the contact element 1 (for insertion of the nut 7) and terminated by an adapter 9 for insertion of the conductor conducting the electrical signal from the electrostimulation device. Per core r «I ·

A hollow cylindrical permanent magnet 3 of highly magnetizable AINiCo alloy is mounted (pressed). The base of the hemispherical contact element 1 is separated from the magnet 3 by a (waterproof) ring-shaped washer 2, which is made of Teflon. The magnet 3 is oriented so that its north pole is on the side of the hemispherical electrode 1.

The electrode assembly formed by the elements 1, 2, X 4, 9 is further provided with a stabilizing disc 6, which is made of transparent plastic, and is fastened to the elastic webbing 5 by means of a nut 7 and a washer 8, enabling fixation of the electrode at a selected location. The elastic strap is made of POP (polypropylene) and is equipped with a buckle.

Claims (8)

PATENT CLAIMS What is claimed is: 1. An electrode for percutaneous neurostimulatory treatment comprising - a hemispherical contact element (1) for application to the skin above the stimulated nerves, a core (4) which is conductively connected to the hemispherical contact element (1), and - a permanent magnet (3) in the form of a cylinder which is coaxially mounted on the core (4) and which is oriented by its north pole to the hemispherical contact element (1). Electrode according to claim 1, characterized in that the permanent magnet (3) has a magnetic surface induction of at least 300 G, preferably 400 G. Electrode according to claim 1, characterized in that the permanent magnet (3) is made of an AlNiCo alloy. An electrode according to claim 1, characterized in that the hemispherical contact element (1) is made of silver. 5. The electrode of claim 1, further comprising an annulus washer (2) mounted on the core (4) and waterproofing the semicircular contact element (1) and the magnet (3). The electrode of claim 1, further comprising an adapter (9) for connecting a lead wire. An electrode according to claim 1, characterized in that it comprises means (5) for fixing to a limb. The electrode of claim 1, further comprising a stabilizing disc (6).