Device for electrostimulation

Abstract

There is disclosed an electro-stimulation device having co-operating male/female locking engagement between an internal electrode connector and an externally facing contact electrode. This arrangement aids easy assembly of the electrostimulation device especially when using a unitary device body to form a self-contained device. The device may be arranged to deliver constant target current to a muscle for electro-stimulation of that muscle. The device may be a completely self-contained device with no external means for the adjustment and control of the electro-stimulation delivered to the muscle during treatment. The microprocessor based device may monitor indirectly the actual current delivered to the muscle during electro-stimulation via measurement of the return path voltage through the muscle and optionally in addition monitors and adjusts for the internal battery voltage during use of the device in order to deliver a more consistent an accurate and effective target output current to the muscle being stimulated at each and every pulse delivered from the device.

Claims

1. A compressible electro-stimulation device comprising a compressible body with at least one electrode at or on the device body surface and corresponding numbers of electrode connectors internal to the body, wherein each electrode and its corresponding electrode connector remain separated from each other upon completed assembly of the device and are adapted to contact with each other and to lockingly engage with each other upon compression of the device body.

2. A device as claimed in claim 1, wherein the compressible body is a unitary compressible body.

3. A device as claimed in claim 1, wherein the electrode or the electrode connector comprises a female connector.

4. A device as claimed in claim 3, wherein the female connector comprises an elongated chamber.

5. A device as claimed in claim 1, wherein the electrode or the electrode connector comprises a male connector.

6. A device as claimed in claim 1, wherein the electrode comprises a female connector and the electrode connector comprises a male connector.

7. A device as claimed in claim 6, wherein the electrode comprises a female connector over molded with electrode material.

8. A device as claimed in claim 6, wherein the female and male connectors snap-fit to each other via an internal locking ridge on the female connector and an external locking ridge on the male connector.

9. A device as claimed in claim 1, wherein the electrode and electrode connector are in sliding locking engagement with each other.

10. A device as claimed in claim 1, wherein the electrode and electrode connector are in engagement with each other and may move one relative to the other upon compression of the device.

11. A device as claimed in claim 1, further comprising a sub-assembly.

12. A device as claimed in claim 11, wherein the sub-assembly comprises guide elements protruding from a sub-assembly housing.

13. A device as claimed in claim 12, wherein the sub-assembly comprises electrode connectors having connector ends in fixed attachment to the sub-assembly.

14. A device as claimed in claim 13, wherein the sub-assembly comprises a proximal and distal end and the electrode connectors are fixed to the sub-assembly at its proximal end.

15. A device as claimed in claim 13, wherein the sub-assembly comprises a proximal and distal end and two electrode connectors one fixed to the sub-assembly at its distal end and the other fixed to the sub-assembly at its proximal end.

16. A device as claimed in claim 1, wherein the body comprises a distal end access point for insertion of a sub-assembly.

17. A device as claimed in claim 16, wherein the distal end access point and the sub-assembly are arranged such that their smallest cross-sectional dimension is aligned with an axis between the device electrodes.

18. A device as claimed in claim 1, further comprising an internal sub-assembly aligned within the device body such that its smallest cross-sectional dimension is aligned with an axis between the device electrodes.

Description

DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to various specific embodiments of the invention as shown in the accompanying diagrammatic drawings, in which:

(2) FIG. 1 (a) shows in perspective view of a preferred form of electro-stimulation device or device for measuring impedance according to the present invention;

(3) FIGS. 2 and 2(a) show a recorded electro-stimulation pulse delivered to a muscle demonstrating the shape of the waveform produced from an individual with the preferred measurement point indicated at 30 s and also the principles for RMS measurements;

(4) FIGS. 3 and 3(a) show a schematic of a preferred circuit for use in the electro-stimulation device or impedance measurement device of the present invention with highlighting of key components to aid description;

(5) FIG. 4 shows a set of steps of a method according to an embodiment of the invention;

(6) FIG. 5 shows components of a microprocessor according to an embodiment of the invention;

(7) FIG. 6 shows a side view of a one-piece unitary body of the present invention;

(8) FIG. 7 shows a top view of a one-piece unitary body of the present invention;

(9) FIG. 8 shows a perspective view of a one-piece unitary body of the present invention;

(10) FIG. 9 shows a view of the distal end of a one-piece unitary body of the present invention;

(11) FIG. 10 shows a view of the proximal end of a one-piece unitary body of the present invention;

(12) FIG. 11 shows a perspective view of a device of the present invention including one-piece unitary body, electrodes, sub-assembly and battery tab;

(13) FIG. 12 shows the perspective view of FIG. 11 with the one-piece unitary body removed to illustrate device internal components and relationships;

(14) FIG. 13 shows the device of FIG. 12 as viewed from its distal end;

(15) FIG. 14 shows the device of FIG. 12 as viewed from its side;

(16) FIG. 15 shows the device of FIG. 12 as viewed from its proximal end;

(17) FIG. 16 shows the device of FIG. 12 as viewed from the top;

(18) FIG. 17 shows the device of FIG. 16 with components removed to show electrode and electrode connector components;

(19) FIGS. 18 (a) and (b) shows an electrode with female locking component with (a) and without (b0 over molded electrode material;

(20) FIG. 19 shows an electrode female connection component;

(21) FIG. 20 shows an electrode connector with male engaging end component; and

(22) FIG. 21 shows the device of FIG. 12 with one of the electrode connectors in locking engagement with the female locking component of the electrode.

DETAILED DESCRIPTION OF THE INVENTION

(23) Referring to FIG. 1 a self-contained electro-stimulation device (1) is shown in the non-compressed, fully expanded state. The device (1) has a unitary body (2) which has been constructed from bio-compatible resiliently compressible foam. Electrodes (3 and 3 not shown) emerge from within the body (2) of the device and are located at the surfaces (4 and 4 not shown) on sides (5 and 5 not shown) of the device (1). The electrodes (3 and 3) are relatively flat. In this particular embodiment the electrodes (3, 3) are in communication with the internal electrode connectors (not shown) of the device (1. They provide electro-conductive surfaces (6 and 6 not shown) that are located in approximately the same plane as the surfaces (4, 4) of the sides (5, 5) of the device. The main body of the flat electrodes (3, 3) are located below the surface (4, 4) of the body (2) within a hollow cavity (not shown) within the body (2) of the device (1). The surfaces (6 and 6) of the electrodes (3, 3) appear through these openings (7 and 7 not shown) of the body (2). In one embodiment the electrodes (3, 3) may be surface mounted on the body (2) of the device (1); in this embodiment the surface mounted electrodes (3, 3) may be in contact with electrode connectors that communicate with the interior components and sub-assembly of the device (1). The interior components of the device (1) are not shown in this Figure but are totally enclosed within the device body and are described in more detail below. The device (1) has a string cord (8) which is attached to the device and is used solely for removal of the device from the vagina. The cord (8) may be made of string or similar materials, plastic materials or for example bio-compatible metal. The device has no external means for controlling or adjusting the device electronics located within the interior of the device body, which fully encloses these device electronics save for the electrodes at the device surface. All of the devices circuitry measurement, control and power components are located within the interior of the device and are inaccessible to the device user. Not shown in this figure is a tab that is inserted into the device body, preferably at the distal, cord end of the device. This tab isolates the internal battery from the measurement and control circuits within the device body. In order to use the device and to activate the measurement and control circuitry this tab is removed enabling the battery to engage with and deliver power to the measurement and control circuitry. Preferably once removed the tab may not be re-insertable into the device.

(24) The dimensions of the device (1) which, in the non-compressed state, are such that the length (L) is greater than the width (w), which is in turn greater than the height (h). This device (1) when viewed in cross-section along the axis of insertion (X) has a non-uniform symmetrical cross-section. This non-uniformity means that the device (1) is less prone to rotation or displacement relative to the axis of insertion (X) during use of the device (1). The device (1) has no sharp edges whilst having clearly defined surfaces that are connected to each other by gently curving regions. The compressible properties of the device (1) ensure resilient contact with the muscles of the pelvic floor during use, its overall dimensions and shape, coupled with the smooth curvature of communicating surfaces, enables the device (1) to be easily and comfortably inserted during use, whilst at the same time limiting or preventing unwanted rotation and displacement during use. The shape and material properties of the device body are such that it is able to be compressed, flexed and change shape when in situ to conform to pressure applied by the interior surfaces of the vagina as they move; such movement especially occurring when the user is mobile.

(25) Referring to FIG. 2 a typical single pulse profile returned after being delivered from an electro-stimulation device to tissue according to the present invention, is shown indicating at point X the preferred point at 30 s for measurement of the return path voltage, for use in the adjustment of the devices power level for delivery of the target output current. Referring to FIG. 2(a) the same single pulse profile is illustrated with regular spaced voltage measurements V.sub.1 to V.sub.11 for use in calculating Volts.sub.RMS.

(26) Referring to FIGS. 3 and 3a, the key components of a preferred circuit for use in the electro-stimulation device or impedance measurement device of the present invention are illustrated. These key components comprise: a microprocessor control unit (100), a return path voltage sensing circuit (200), a treatment voltage sensing circuit (300), a DC block (400), an output switch (500), a limit (600) and a voltage control unit (700). It is preferred that the device of the present invention comprises as a minimum a microprocessor control unit (100), a return path voltage sensing circuit (200), an output switch (500) and a voltage control unit (700). It is most preferred that the device of the present invention comprises all these circuit components.

(27) The key components in FIGS. 3 and 3(a) are as follows:

(28) TABLE-US-00001 700 L1 inductor R7 resistor D3 diode Q5-2 NPN/NPN transistor C4 ceramic capacitor 600 D2 30 volt Zener diode 500 Q6-2 NPN/PN transistor Q6-1 NPN/PN transistor Q5-1 NPN/NPN transistor R10 resistor 400 C5 ceramic capacitor 100 U1 Microprocessor 300 R5 resistor R6 resistor 200 C8 ceramic capacitor D9 Schottky Diode R9 resistor C1 ceramic capacitor C2 ceramic capacitor R8 ohm resistor

(29) The complete operation of the circuit is run by the microprocessor control unit (100). This comprises a microcontroller complete with A/D measurement inputs of battery voltage and the return path voltage. These inputs allow the microcontroller to set the correct output voltage to ensure that the target output current is delivered and maintained. The microprocessor also controls various other parameters for the electro-stimulation treatment cycle such as pulse profiles, pulse frequencies, pulse sequences, pulse intensity and pulse duration of the output pulses. The pulse frequencies and sequences are preferably as per those described in patent ref WO97/47357 and U.S. Pat. No. 6,865,423 or they may be any other suitable patterned stimulation programme. The microprocessor is preferably an 8 bit processor. The microprocessor is programmed with a target return path voltage; this is proportional to the target output current and the return path voltage is used to adjust the output voltage to deliver the target pulsed output current. As previously stated the microprocessor controls the pulse duration for the electro-stimulation treatment pulses. The microprocessor generates a Pulse Width Modulated (PWM) square wave to generate a variable increased voltage (the treatment voltage) via communication with the voltage control unit (700). The microprocessor (100) measures the treatment voltage via the treatment voltage sensing circuit (300). The microprocessor (100) measures the return path voltage via the return path voltage sensing circuit (200) and compares this measured voltage to the programmed target output voltage value in the microprocessor and this comparison is used to adjust the PWM signal to the voltage control unit (700) in order to adjust the output voltage power level for a subsequent treatment pulse to a level required to achieve the target pulsed output current. The microprocessor (100) also monitors the voltage levels being delivered to the user and via use of a pre-programed algorithm caps the output voltage level at a predetermined maximum level to prevent excessive voltage if for example the resistance in the circuit is too high. The microprocessor (100) is capable of recording all data measured and calculated within the device for future analysis. The microprocessor (100) also times and controls the length of electro-stimulation bursts and overall duration of the treatment.

(30) The voltage control unit (also referred to as voltage boost) (700) receives PWM signal pulses from the microprocessor (100) to control the power level delivered to the user. The battery output, which is typically 3 volts may be and preferably is boosted via the voltage control unit (700) to a maximum of 35 volts from the limited power available in a button cell battery. The PWM signal from the microprocessor (100) drives a transistor Q5-2 and grounds an inductor L1. When grounded the inductor L1 draws current and generates an electrical field proportional to the current (derived from the width of the PWM on time). When the transistor Q5-2 does not conduct, the magnetic field collapses generating a voltage in the inductor L1. This voltage is higher than the battery voltage and proportional to the PWM signal. The bigger the ON to OFF ratio in the signal the higher the voltage generated in inductor L1. The PWM signal is approx. 50 kHz. This high frequency ensures that the battery does not have to supply current for a long period of time. The PWM pulse widths are between 1 s and 10 s, depending on the instructed duty cycle. Each PWM pulse draws 100 mA for a very short period of time dependent upon the PWM ON cycle. This voltage flows through the diode D3 and is stored by the capacitor C4. The diode D3 acts as a one-way valve and stops the charge on the capacitor C4 from leaking away when the boosting signal is not being generated by the microprocessor (100). The whole operation of boosting the battery voltage takes place prior to the initiation of every treatment pulse and lasts for typically 10 mS.

(31) For the avoidance of doubt, it is noted here that the treatment pulses are distinct from the pulses of the PWM signal. The treatment pulses are the pulsed current used for the electro-stimulation of the muscle via the electrodes, as described herein, with pulses for example at 250 s width, and at intervals of 8 mS to 500 mS.

(32) The circuit also comprises a voltage sensing circuit (300). This component is used to provide feedback to the microprocessor/controller (100) and is used to sense the treatment voltage level. Voltage measurement is provided by resistors R5 & R6, & C7 these act as a ladder divider and divide the treatment power level by a factor of 10. This is needed because the treatment power level is much higher than the battery voltage. So a desired maximum power level of 20 volts is divided down to 2 volts for the microprocessor (100) to measure. This is measured approximately 40 s after the start of the treatment pulse (After Current feedback) C7 acts as a filter to ensure a smooth level to be measured. This voltage measurement is used in conjunction with the return path voltage feedback to limit output voltage in case of high user impedance in the circuit and is an optional but preferred safety feature. Thus the devices of the present invention preferably comprise a voltage sensing circuit.

(33) Capacitor C1 is a reservoir which supports the battery during boost, preventing battery voltage droop. Capacitor C2 filters high frequency interference from the microprocessor.

(34) The device circuit also preferably comprises a fallback voltage limiter which is only used in the case of a failure in feedback or software (600). In a preferred embodiment this takes the form of a zener diode D2, which is not used under normal conditions. Its function is to limit the maximum treatment level of the device to 30 volts. The power level required for the preferred electro-stimulation device of the present invention is typically from 10 to 20 volts, more preferably 10 to 18 volts and most preferably 12 to 18 volts, with a specified maximum of around 26 volts. Any failure in feedback or software that could create an undesirable output voltage level is restricted to 30 volts by the zener diode, thus limiting the output voltage delivered to a user to a totally safe level.

(35) The device circuit also comprises a return path voltage sensing component (200), which preferably uses measurements of return path voltage taken at 30 s into the electro-stimulation pulse. This component is used to measure the return path voltage during use of the device which at the known resistance of the resistor used in the circuit is proportional to the current being supplied to the muscles of the user. This return path voltage is monitored to ensure that the user is receiving the required target output voltage and thus the target pulsed output current and is an important feature of the present invention. This measured return path voltage is compared to the target for return path voltage related to the output voltage required to deliver the target pulsed output current and the power level boosting signal from the microprocessor (100) is adjusted accordingly to ensure the output voltage of operation is adjusted to deliver the target pulsed output current. This measurement is undertaken by use of resistor R8 and optionally with R9 & C8. The return path current from the user flows through sense resistor R8. The current through this resistor is exactly the same as through the pelvic floor muscle of the user. The current is related to the return path voltage according to the formula I=V/R. The return path voltage across this resistor is determined preferably for each pulse. Resistor R9 and capacitor C8 are optional and provide a limiting and filter function to ensure that static, body movement and DC potential due to muscle activity and chemistry do not influence the return path voltage. The large value of R9 limits any external voltages and protects the microprocessor (100), preventing damage and the effect of excessive measurement values. In combination with C9 it also forms a shaping filter, this rounds and softens the shape of the return path voltage. The return path voltage is measured by R8 30 s after start of a treatment pulse. This gives a relatively stable and consistent place to measure the return path voltage for output voltage adjustment. Diode D9 is used to prevent excessive voltages due to static or failure of the current sensing components. D9 is effectively two Zener diodes back to back and limits surges from any polarity.

(36) The circuit also comprises an output switch (500). This section of the circuit switches the operation voltage level to the user and under control by the microprocessor creates the output pulse waveform for the treatment cycle. After each pulse the electrodes (3, 3) of the device (1) are grounded. This creates the asymmetrical waveform and grounds the user between pulses to remove any DC potential from the skin. The capacitor C5 (400) ensures that there is no DC to the user in normal use and prevents DC being applied in a fault condition should the output switch (500) be faulty. This output switch (500) switches the stored output voltage to the user from capacitor C4. It consists of an NPN and PNP pair of transistors Q5-1 & Q6-2. The microprocessor (100) switches on Q5-1, which in turn switches on Q6-2. These transistors operate in this fashion because the switched power level is higher than the battery voltage and could not be switched by a single transistor; therefore, preferably the output switch (500) comprises at least two transistors and preferably at least one NPN and at least one PNP transistor. Q6-1 transistor grounds the output capacitor C5 until a pulse is delivered to the user. This ensures that there is no voltage applied to the user before a pulse, and also reverses the charge on capacitor C5 to deliver a negative waveform to the user and also zeroes the charge on the capacitor before each pulse to ensure that they are all the same size. In operation Q6-1 is preferably always switched on until 1 s before a treatment pulse is generated then it is switched off. When Q6-1 is switched off transistors Q5-1 & Q6-2 are switched on for the duration of the pulse then they are switched off. After the treatment pulse there is a 1 s delay and then transistor Q6-1 is switched on to ground capacitor C5.

(37) The VRef is a reference measurement of the battery level after the desired power level has been delivered via the voltage control unit (700). Inside the microprocessor (100) is a reference diode (not shownsee FIG. 5) that can be measured by the microprocessor (100). This is preferably measured at 50 s or later after a treatment pulse is initiated. This gives an accurate indication of battery voltage after the boost is completed as described above.

(38) In more detail, the outputs of the microprocessor 100 (U1 as shown in FIG. 3) are as follows:

(39) OUTCNTRL1output controlthis switches the boosted voltage to the user (OUTCNTL2 will be off when OUTCNTRL1 is on);

(40) OUTCNTRL2this switches DC block capacitor C5 to 0 volts, generating a negative pulse (OUTCNTRL1 will be off);

(41) BOOSTthis is the PWM signal, instructing the voltage control unit (700) to boost from 3 volts to treatment level as described above;

(42) BOOSTMONITORthis is the voltage feedback from the boosted signal, as described above regarding the treatment voltage sensing circuit 300; this is used as described above in conjunction with current feedback to control output; and

(43) ISENSEthis is the current feedback from the user, as described above regarding the return voltage sensing circuit 200.

(44) In a specific embodiment, the whole circuit shown in FIGS. 3, 3a may generally be operated as follows. At switch on, there is a 10 second delay. Then the device begins electro-stimulation in the initial constant low voltage mode. The microprocessor (100) is programmed to generate a low voltage (below the treatment power level) and starts the treatment at this low voltage and uses voltage feedback to maintain an output voltage of 10 volts. After this first phase the microprocessor (100) switches to the current ramp mode with increasing voltage to reach the voltage required to deliver the target output current for treatment. On completion of the current ramp mode the device moves into the treatment cycle. In this phase the return path voltage is measured and is compared to a target return path voltage related to the target output current value stored in the microprocessor (100) to determine the output voltage required to deliver the target output current during at least one subsequent electro-stimulation pulse and to do this at each and every pulse to ensure that the target output current is delivered to the users muscles. After this point the device continues to operate in current feedback mode via measurement of return path voltage for the remainder of the treatment and the return path voltage is then continuously measured. If the measured return path voltage is different form the target return path voltage indicative of target output current, then the PWM value (duty cycle) is increased or decreased for the pulses delivered to the user. This is repeated until the required target output current is reached (the measured return path voltage equals the target return path voltage value). During use of the device this is preferably monitored and determined at every pulse. As the user moves contact with the pelvic floor will be improved or reduced resulting in the current delivered increasing or reducing. The device will adjust the PWM value to correct the output voltage of the device in order to maintain a constant target output current to the user. The placement of the device, hormonal cycle and tone of muscle from user to user will also affect the output voltage required to deliver the target output current. The microprocessor (100) has a PWM (duty cycle) which has a range of values typically required to achieve the required output voltage to effectively treat a range of users.

(45) With reference to FIGS. 3 and 3(a), when it is desired to invoke a battery depletion routine this may be achieved under control of the microprocessor (100) by ensuring that output transistors OUTCONTROL1 and 2 are switched ON, whilst isolating the electrodes and continuing to draw power from the battery to provide a continuing BOOST cycle until the battery is depleted as power is drained through the inductor. Typically, the device will cycle at 10V boost level until the battery is depleted and fully discharged.

(46) FIG. 4 is a diagram illustrating the general delivery method of the present invention at step (42) the device under microprocessor control provides the appropriate output voltage for delivery of the desired target output current for electro-stimulation and this is delivered to the muscle as a pulse of electro-stimulation. Then at step (43) the muscle has contracted under electro-stimulation and the return path voltage is measured. As indicated this is preferably measured at 30 s after the muscle has started to contract. At step (44) the microprocessor uses the measured return path voltage at step (43) to determine if the output voltage delivered at step (42) was too high or too low to deliver the target output current. If it is determined that the output voltage at step (42) was neither too high or too low and actually delivered the target output current to the muscle, then step (42) is simply repeated; if this is consistently the result at step (44) then the cycle of steps 42 to 44 and return to 42 is simply repeated until a variance is determined at step (44). If a variance is determined at step (44), which indicates that the output voltage at step (42) was too low to achieve the target output current then a further step (45) is invoked to increase the output voltage delivered at step (42). If a variance is determined at step (44), which indicates that the output voltage at step (42) was too high to achieve the target output current then a further step (46) is invoked to increase the output voltage delivered at step (42). Thus by determining the return path voltage at step (43) and using that value at step (44) in a determination of the accuracy of the output voltage at step (42) for delivery of the target output current the device is able to consistently deliver target output current to a user. This routine illustrated in FIG. 4 is ideally undertaken at each and every pulse in the treatment cycle.

(47) FIG. 5 is a diagram illustrating the microprocessor (100) from the previous Figures. It should be noted that certain of the above embodiments of the invention may be conveniently realized as a computer-implemented or processor-implemented system suitably programmed with instructions for carrying out the steps of the delivery methods according to embodiments of the invention. The computing device or system may include software and/or hardware for providing functionality and features described herein. For example, FIG. 1 illustrates a housing which contains components of the device, FIGS. 3 and 3a illustrate components of the hardware inside the housing which implement features of the invention, and the microprocessor 100 which may be programmable with such instructions. In alternative embodiments, the programmable elements contained by the housing may take different forms, and indeed some features of the invention may be implemented by external computer-implemented or processor/controller systems which are adapted to communicate with the device 1 via electrodes 8 before and after use of the device.

(48) The computing device(s) or system(s) may include one or more of logic arrays, memories, analogue circuits, digital circuits, software, firmware and processors. The hardware and firmware components of the device/system may include various specialized units, circuits, software and interfaces for providing the functionality and features described herein. For example, a central processing unit such as the microprocessor 100 is able to implement such steps as instructing provision of an initial output voltage for delivery of the target output current for electro-stimulation, and measuring a return path voltage at a specified period of the return voltage pulse.

(49) The microprocessor (100) shown in FIG. 5 may be or include one or more microprocessors or processors such as processor 55 shown in FIG. 5, and in other embodiments, the processing used in the device may include application specific integrated circuits (ASICs), programmable logic devices (PLDs) and programmable logic arrays (PLAs).

(50) Data can be received and transmitted by ports or interfaces or data I/O (56), for example providing the inputs and outputs described above regarding microprocessor 100 (U1 in FIG. 3/3a). The data I/O can also provide communication with external components, which may provide instruction or further processing. Such components could provide a direct link with apparatus or a connection to a network. For example, in embodiments of the invention the external connection may be to a networked user device, with which a user interacts.

(51) In embodiments, software applications loaded on memory 54 may be executed to process data in random access memory 53. The memories 53 and/or 54 may be or include RAM, ROM, DRAM, SRAM and MRAM, and may include firmware, such as static data or fixed instructions, BIOS, system functions, configuration data, and other routines used during the operation of the computing device and/or processor. For example, the RAM 53 may store data such as reference or standard values of return voltage, or previous values of voltage output, and the memory 54 may store the software instructions to implement delivery methods such as determining the next output voltage value based on the latest return voltage.

(52) The memory also provides a storage area for data and instructions associated with applications and data handled by the processor. The storage provides non-volatile, bulk or long term storage of data or instructions in the computing device or system. Multiple storage devices may be provided or available to the microprocessor 100 or any external computing device/system, for the latter of which some may be external, such as network storage or cloud-based storage.

(53) The computer or processor implementable instructions or software may for example contain separate modules or components for handling certain of the following steps of delivery methods according to embodiments of the invention: generating a required output voltage level to achieve a target output current; measuring return path voltage through the muscle; adjusting the output voltage required to achieve the target output current for subsequent electro-stimulation based on the measurement of return path voltage; or determining a return voltage over a portion of the return voltage pulse, or at a specific point of the pulse.

(54) In embodiments, the microprocessor 100 also houses, as described above, the voltage reference diode (57), which allows for example the memories 53 and 54 storing values and instructions to the processor (55) to scale the voltage value returned according to the true level of the battery.

(55) With reference to FIGS. 6 to 10 there is shown a one-piece molded unitary body (60). The body (60) has a top (61), a bottom (62) a proximal end (63) and a distal end (64). These figures clearly illustrate the arrangement for the three open access points required for effective assembly of the finished device. FIGS. 6 and 8 show the electrode side opening (66), which is present on both sides of the body (60). These electrode body openings (66) are present to enable the internal components of the device (1) to communicate with and connect to the electrodes (3) of the device. Also show in FIGS. 6 and 8 are electrode recesses (65) at the surface of the body (60). These electrode recesses (65) are present to allow the top outwards facing surfaces of the electrodes (3) to sit flush with the external surface of the body (3). Thus the two electrode access point side openings (66) consist of relatively large area shallow recesses (65) that are designed to accommodate the majority of the electrode material. Towards the center of each electrode access point (66) is a passage to the interior of the unitary body (60) which is in communication with the other access point passages. This passage is shaped in part to accommodate the female engagement means (120 in for example FIG. 12), which is located at the rear of each electrode (3) and in addition an elongated slot portion (68), which is arranged to accommodate male part (123) of the electrode connector (121 in for example FIG. 12) once it is engaged with the electrode female engagement means (120). FIGS. 7, 8 and 9 shows an opening (67) at the distal end (64) of the body (60), this opening is the distal end access point (67), . . . , which is as illustrated oval in shape and is orientated to ensure that the sub assembly (122 shown in for example FIG. 12) and electrode connectors (121) are inserted with the male part (123) of the electrode connectors (121) facing each electrode access point (66). It can be seen that with this arrangement and the use of an oval shaped sub-assembly (122) the body (60) is able to be further compressed along the axis (x-x shown in FIG. 9) than would be possible if the distal end access point (67) and the sub-assembly (122) were rotated by 90 degrees. Thus the distal end access point (67) and the sub-assembly (122) are preferably always orientated such that their narrowest dimension is along the axis (x-x) between the electrodes (3).

(56) With reference to FIG. 11 a complete device (1) is illustrated with electrodes (3), sub-assembly (122) and battery tab (124) in place within the one-piece unitary body (60).

(57) With reference to FIG. 12 the complete device (1) of FIG. 11 is illustrated with the one-piece unitary body (60) removed to expose the remaining components of the device (1) and their spatial relationships. The two electrodes (3) can be seen arranged either side of the sub assembly chassis (122). The electrodes (3) have two parts one is a large flat contact area (125) over molded onto internally facing female connecting means (120). One of the electrode connectors (121) with male connector (123) at its free end can also be seen attached to and lying flush against the housing (126) of the sub assembly (122). It can be seen that the electrode female connection (120) is aligned with the male end connector (123) of the electrode connector (121). Also illustrated are guides (127) protruding from the sub assembly housing (126). These are aligned in the direction of insertion of the sub assembly (122) into the unitary body (60) and sit either side of the male end connector (123) on the electrode connector (121). It can be seen that if the electrode (3) is moved in plane towards the electrode connector (121) the guide (127) will ensure that the electrodes female connector (120) and male connector (123) are guided towards each other. These components and their spatial relationships are further illustrated from differing perspectives in FIGS. 13 to 17. With reference to FIG. 17, it can be seen that the electrode connectors (121) may be secured at their ends (130) with a clip formation to the proximal end (129) of the circuit board (131); although they are both attached to the proximal end (129) of the circuit board (131) they are electrically isolated from each other. In an alternative embodiment one of the electrode connectors (121) may be secured to the circuit board (131) at the distal end (132) of the circuit board (131) via its end (130); in this arrangement the electrode connector ends (130) are located at their maximum distance from each other whilst connected to the circuit board (131) and this offers the maximum possible electrical isolation of the electrode connectors (121).

(58) With reference to FIGS. 18 and 19 an electrode (3) having a large flat contact region (125), which comes into contact with muscle to be electro-stimulated and a female connector (12). FIG. 18(a) shows the contact material (125) formed as an over molded component on the female connector (120). FIGS. 18 (b) and 19 show the female connector (120) with the over molded contact component (125) removed. Also illustrated in FIG. 19 is an internal locking ridge (133), which is located around all or a part of the sidewall internal circumference of an elongated female chamber (135) within the female connector (120). This internal ridge (133) co-operates with the externa locking ridge (134) located on the exterior of the male connector (123) for providing a snap-lock engagement of the female component (120) with the male component (123).

(59) With reference to FIG. 20 an electrode connector (121) is illustrated with a clip end (130) designed to clip to and provide electrical contact with the PCB (131) of the sub-assembly (122) The clip end (130) when engaged with the PCB (131) and sub assembly housing (126) is relatively immobile within the device. At the opposite end of the electrode connector (122) is shown a male connector (123) for co-operation with the female connector (120) of the electrode (3). This male connector (123) is substantially circular and around its upstanding exterior wall is bisected by an annular external locking ridge (134), which is designed to co-operate and engage with the corresponding interior locking ridge (133) of the female component (120) of the electrode (3). The male end connector (123) and the clip (130) are connected to each other by an elongated arm section (136), which is able to flex about the relatively fixed clip point (130) of the electrode connector (121), when secured to the PCB (131). This means that whilst the clip end (130) of the electrode connector (121) is spatially fixed within the device (1) the male component (123) at the opposite end of the elongated arm section (136) has the potential for spatial mobility within the body (60) of the device (1). As a consequence, once connected to the female connector (120 of the electrode (3) the male connector (123) is able to move with electrode (3) movement. In the embodiment illustrated the elongated arm section (136) is substantially planar and this means that spatial movement of the male end (123) is largely restricted to a direction perpendicular to the plane of the elongated arm section (136). If the elongated arm section (136) is circular in cross-section or substantially non-planar e.g. oval in cross-section, then the degrees of spatial freedom of movement for the the male end connector (123) are increased as a circular cross section elongate arm member (136) may flex in more directions than a planar cross-section elongate arm member (136).

(60) FIG. 21 illustrates one of two male connectors (123) of the electrode connectors (121) connected to and engaged with the correspond female connector (120 of an electrode (3). The male connector (123) of the electrode connector (121) is located within and in locking engagement with the female connector (120) of the electrode (3).

(61) All of the features disclosed in this specification for each and every aspect and/or embodiment (including any accompanying clauses, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

(62) Throughout the description and clauses of this specification, the words comprise and contain and variations of the words, for example comprising and comprises, means including but not limited to, and is not intended to (and does not) exclude other components, integers or steps.

(63) Throughout the description and clauses of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. Features, integers, characteristics, compounds described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

(64) Each feature disclosed in this specification (including any accompanying clauses, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

(65) The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying clauses, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.