WO1994027673A1

WO1994027673A1 - Neuro-muscular stimulator

Info

Publication number: WO1994027673A1
Application number: PCT/GB1994/001143
Authority: WO
Inventors: Richard Duncan Bradbury Robinson; Carole Brown
Original assignee: Robinson & Sons Limited
Priority date: 1993-05-26
Filing date: 1994-05-26
Publication date: 1994-12-08
Also published as: AU6800994A; GB2278547A; GB9310889D0

Abstract

A neuro-muscular stimulator for automatic stimulation of pelvic floor muscles to relieve stress incontinence comprises an adhesive electrode (8) for application to the exterior of the perineum and a power supply unit (1) connected to the electrode. A second electrode (9) is provided on the power supply unit which is adapted to be secured to the leg of a wearer in a manner which automatically places the second electrode into electrical contact with the leg of the wearer. The power supply unit operates automatically to supply spaced apart packets of stimulation pulses to the electrodes. Preferably, the power supply unit is switchable to provide pulses of alternative frequency and is adjustable to provide user selected pulse amplitude.

Description

NEURO-MUSCULAR STIMULATOR

This invention relates to a neuro-muscular stimulator and more particularly to a neuro-muscular stimulator for toning the muscles of the pelvic floor to relieve stress-related incontinence.

The application of electric pulses to the perineum is a well-known technique for alleviating incontinence by toning up the muscles in that region. However, in previous devices the perineal electrode has been provided as a vaginal plug which may be inconvenient or difficult to fit and may lead to discomfort for the user.

According to the present invention there is provided a neuro-muscular stimulator comprising a first, perineal electrode, a second electrode, and a power supply unit for supplying electrical pulses to the electrodes, wherein said first electrode is adapted to be placed externally over the perineum of a user.

Preferably, the first electrode comprises a self- adhesive electrode pad.

In a preferred embodiment, the second electrode comprises an electrode pad located on the power supply unit. Because this second electrode is an integral part of the power supply unit, it does not need to be positioned separately, as is required in known units.

Preferably, the power supply unit is adapted to be worn on a leg of the user with the second electrode pad in contact with the leg, and may be secured to the upper thigh by means of a band of elastic webbing incorporating means for adjusting the length of the band to suit the user's requirements.

In a particularly preferred embodiment, the stimulator additionally comprises a control unit connected to the power supply unit, the control unit being programmable to control the supply of electrical pulses from the power supply unit to the electrodes in accordance with a preselected program.

The power supply unit is preferably battery- operated and may incorporate an indicator for providing a warning when the battery or batteries need replacing.

Control means are preferably provided on the power supply unit for adjusting the amplitude of the electrical pulses, and these control means may be a push button or buttons which are preferably covered by a membrane such that the power supply unit is substantially splash proof should it come into contact with water, urine or other liquids.

The present invention will now be described in more detail by way of example with reference to the accompanying drawings, in which:

Figure 1 is a general view showing a neuro- muscular stimulator strapped to the leg of a user;

Figure 2 shows a schematic rear view of the neuro- muscular stimulator of Figure 1;

Figure 3 shows a front perspective view of the stimulator in more detail; and

Figure 4 shows a further rear view of the stimulator.

As shown in Figure 1 the stimulator power supply unit 1 is designed to be worn on the leg 2 of a user 3. The stimulator power supply unit is secured to the leg by webbing 4.

As can be seen more clearly in Figure 2, the webbing preferably comprises elastic webbing with a VELCRO (Registered Trade Mark) or other suitable fastening 5 such that the webbing provides a garter which can be adjusted to the length required to hold the unit securely on the leg of any individual user, but any other means of supporting the unit on the leg may be used, and it is also envisaged that the unit may be supported on a different region of the anatomy of the user.

The power supply unit has a plug socket 6 into which can be fitted a flexible lead 7 connecting the unit 1 to a perineal electrode pad 8. A second electrode pad 9 is provided on the rear of the stimulator Unit 1. The perineal electrode pad 8 forms a positive electrode, while the second electrode pad 9 forms a negative electrode.

In use, the stimulator unit 1 is fitted to the leg of the user, as shown in Figure 1, with the second electrode 9 in contact with the skin, preferably on the outside of the upper thigh of either leg of the user. The perineal electrode 8, which is self-adhesive should then be placed over the perineum (i.e. between the anus and vagina). The perineal electrode may also cover the urethra. The lead 7 should then be plugged into the socket 6 ready for treatment.

In order to ensure good electrical contact, the second electrode pad 9 should be coated with a water soluble gel prior to fitting to the leg. Alternatively, soap and water can be used as a coating, but this may need to be reapplied during the treatment in order to ensure that the electrode pad stays moist.

The power supply unit incorporates a control unit and is adapted to supply electrical pulses to the electrodes. The power is provided by a battery or batteries which are fitted in battery compartment 10 (see Figure 4). The control unit is pre-programmed to provide a particular preselected pattern of pulses when the stimulator unit is active, the frequency and duration of the pulses being programmed for the most effective treatment.

The stimulator unit 1 incorporates a transformer so that the voltage across the electrodes can be adjusted, and thus the amplitude of the pulses can be controlled. Amplitude buttons 11a and lib (see Figure 3) provide the control means for increasing or decreasing the amplitude, respectively, to a level that is comfortable to the user. These buttons 11a and lib are preferably push buttons covered by a membrane which keeps out moisture and dirt, such that the stimulator unit is substantially splash proof.

A red light 12 is provided on the unit which lights up or flashes on start-up to show when the battery needs replacing. A yellow light 13 flashes to indicate when the electric current is passing to the user's muscles. Current only passes to the user in pulses during the active phase of the unit. In addition, the amplitude only increased during the active phase not when the yellow light is off. Thus, if one of the amplitude buttons is pressed for a long time, the user does not receive an electric shock, as can happen with some of the previously known devices.

The stimulator unit uses a single chip microcontroller to control its functions and may also be provided with a memory which records and monitors the pattern of use of the unit. The unit preferably has a low current mode which enables it to remain in a stand-by state for up to a year, without running down the alkaline battery.

An internal analogue-to-digital converter is used, in conjunction with an integrating capacitor and ramp up/down circuitry, to achieve a stable electrical pulse amplitude, and an almost linear increase/decrease in the pulse voltage in response to pushing either of the amplitude buttons 11a, lib. The converter is also used to check the battery voltage on exiting from the stand-by state.

The unit may be programmed to operate in two different phases, I and II, where the frequency and/or duration of the pulses are different in the two phases. A switch 14 may then be provided on the unit, as shown in Figure 3, for switching between phase I and phase II and back again. The unit is also designed to automatically switch off should the perineal electrode 8 be unplugged, or should the amplitude of the pulses be reduced to zero, or remain below a minimum effective level for a set length of time, e.g. two minutes.

A particular therapy programme will now be outlined as an example, in order to clarify the operation of the neuro-muscular stimulator.

The unit is intended to be active for 1 hour a day. For the first eight weeks, the unit is active for one hour a day on phase I, while for a final two weeks of treatment, the unit is active for one hour a day on phase II. When active, the unit pulses on for four second and then off for four seconds, and the yellow light 13 flashes at one flash per second in the "on" mode, but is off during the "off" or rest mode.

When switched to phase I the electrical pulses are provided by the unit at lOHz, and when switched to phase II the pulses have a frequency of 35Hz.

The pulse width is 80 microseconds, and each pulse is rectangular in shape, having a positive pulse followed by a negative pulse decaying to zero, such that there is no nett d.c. component. The amplitude of the pulses can be increased up to 50V, as required, and automatically starts at zero at the beginning of each active phase.

Pressing amplitude button 11a will automatically start an active phase of the treatment. When either of the buttons 11a or lib are pressed, the unit will pulse continuously, so that the effect of the increase or decrease in output amplitude can be felt immediately. The normal on mode of operation will resume when the button is released. The unit can be switched off by pressing the decreasing amplitude button lib twice.

The unit will automatically switch itself off after 60 minutes of treatment. The electrode plug may then be removed and the unit unstrapped from the leg. The perineal electrode should then be removed and stored ready for re-use. If, for any reason, a treatment session has to be interrupted, the unit can be switched off by removing the electrode lead 7 from the socket 6. The session can then be restarted afresh immediately or at a more convenient time, without any adverse effect.

The battery can be checked when the unit is not fitted to a user and when the perineal electrode is not connected, simply by pressing button 11a. If the battery strength is insufficient the red light 12 will be activated.

Claims

1. A neuro-muscular stimulator comprising: a first, perineal, electrode; a second electrode; and a power supply unit for supplying electrical pulses to the electrodes characterised in that the first electrode is adapted to be placed externally over the perineum of the user; the second electrode is provided on the power supply unit; and the power supply unit is adapted to be mounted on the user in a manner which places the second electrode in electrical contact with the skin of the user.

2. A neuro-muscular stimulator according to claim 1 characterised in that the power supply unit is adapted to be mounted on the leg of the user and is provided with means for securing the unit to the leg of the user with the second electrode in electrical contact with the leg of the user.

3. A neuro-muscular stimulator according to claim 1 or claim 2 wherein the first electrode is an adhesive electrode adapted to be secured by adhesive means to the perineum of the user.

4. A neuro-muscular stimulator according to any preceding claim wherein the power supply unit comprises control means selectively operable to provide alternative pulse patterns to the electrodes.

5. A neuro-muscular stimulator according to claim 4 wherein the control means is operable to provide pulses of a first frequency or, alternatively, pulses of a second frequency to the electrodes.

6. A neuro-muscular stimulator according to claim 5 wherein the first frequency is 10H_Z and the second frequency is 35H_Z.

7. A neuro-muscular stimulator according to any of claims 4 to 6 wherein each pulse pattern comprises periods during which pulses are sent to the electrodes alternating with periods during which no pulses are sent to the electrodes.

8. A neuro-muscular stimulator according to any of claims 4 to 7 wherein the amplitude of the pulses is selectively variable by the user.

9. A neuro-muscular stimulator according to claim 8 wherein, at the commencement of each period of use of the stimulator, the amplitude of the pulses is pre-set to a minimum value and is then varied by the user to an acceptable value which is maintained during the remainder of the period of use or until re-set by the user.

10. A neuro-muscular stimulator according to any preceding claim wherein the stimulator automatically switches off after a predetermined period of use or if the first electrode is disconnected from the power supply unit.