Device for detecting conductivity

Abstract

An apparatus (30) for detecting electrical conductivity between a subject (41) and a device (1) for electrical stimulation of the subject (41) is described. The apparatus (30) includes a first electrical contact (51) adapted to contact the subject's (41) skin at a first location (42) and a second electrical contact (52) adapted to contact the subject's (41) skin at a second location (43). Also present is a processor (21) having an output coupled to the first electrical contact (51) and an input coupled to the second electrical contact (52), and an output device (26) coupled to the processor (21). The processor (21) is configured to output an AC voltage signal (40) to the first electrical contact (51) and receive a response signal from the second electrical contact (52).

Description

Technical Field

[0001] The present invention relates to a device for detecting conductivity, and more particularly to a device for detecting the conductivity between a subject and a device for electrical stimulation of the subject.

Background Art

[0002] Electrical stimulation of a subject for improving circulation is known. In particular, electrical stimulation of the feet and legs of a subject for improving venous blood flow is known and reported in the art. For example, Kaplan, R. E. et al., "Electrical foot stimulation and implications for the prevention of venous thromboembolic disease" (Thrombosis and haemostasis, 2002, vol. 88, no. 2, pp. 200-204) describes the results of an experiment conducted on a subject, in which a weak electrical stimulation was applied to the calf or sole muscle of the subject. The analysis showed an increase in the intramuscular femoral and popliteal blood flow of the subject on the side where the electrical stimulation was applied compared to the non-stimulated side.

[0003] Furthermore, W Man, I. O., et al., "Effect of neuromuscular electrical stimulation on foot / ankle volume during standing" (Med Sci Sports Exerc., April 2003, 35(4), pp. 630-634) reported that neuromuscular electrical stimulation of the calf muscles of a subject prevented the increase in the volume of the feet and ankles commonly experienced after standing for a long time. It was concluded that neuromuscular electrical stimulation provides a means for reducing the swelling of the lower limbs of a subject who is unable to fully activate the muscle venous pump.

[0004] Faghri, PD, et al., "Electrical stimulation-induced contraction to reduce blood stasis during arthroplasty" (IEEE Trans Rehabil Eng., March 1997, 5(1), pp. 62-69), reports data suggesting that continuous electrical stimulation-induced contraction can improve lower leg circulation in subjects by drawing out the physiological muscle pump. This, in turn, could lead to improved intravenous circulation and reduced congestion during, for example, hip and / or knee prosthesis surgery. The authors suggest that this technique may provide superior protection against deep vein thrombosis (DVT) and pulmonary embolism (PE) during surgery compared to commonly used sequential compression devices and techniques.

[0005] Faghri, PD, et al., "Venous hemodynamics of the lower extremities in response to electrical stimulation" (Arch Phys Med Rehabil., July 1998, 79(7), pp. 842-848), concluded from experiments conducted that periodic, single-electrical stimulation-induced calf muscle contractions can generate significant muscle pump function and be used to improve intravenous blood flow and reduce lower leg congestion, while continuous electrical stimulation-induced contractions can improve periphery of the lower leg while drawing on the physiological intravenous muscle pump.

[0006] Anderson, SI, et al., "Chronic transcutaneous electrical stimulation of calf muscles improves functional capacity without inducing systemic inflammation in claudicants" (Eur J Vasc Endovasc Surg., February 2004, 27(2), pp. 201-209), reported that chronic electrical muscle stimulation is an effective treatment for alleviating intermittent claudication. This technique, involving targeted activation of small muscle masses, does not induce significant systemic inflammatory responses.

[0007] A method of neuromuscular stimulation for the prevention of venous thrombosis and pulmonary embolism is disclosed in U.S. Patent No. 5,358,513 (Patent Document 1). The method involves applying electrical stimulation to a subject using electrodes attached to the anterior portion of the subject's knee, directly proximal to the common peroneal nerve. The electrical stimulation is applied as a series of pulse-modulated sine waves.

[0008] More recently, U.S. Patent No. 6,615,080 (Patent Document 2) discloses nerve electrical stimulation of the foot muscles of subjects for the prevention of deep vein thrombosis (DVT), pulmonary embolism (PE), and lower extremity edema. The method involves applying electrical pulses to the foot muscles in a short wave pattern with variable frequency, duration, intensity, ramp time, and on-off cycle. The electrical stimulation is applied to the soles of the subjects' feet to reduce blood pooling in the soleus vein.

[0009] Devices for electrical stimulation of subjects are known and commercially available. In particular, devices for applying electrical stimulation to the subjects' feet (especially the plantar muscles) are known and commercially available. One example of such a device is the REVITIVE® Circulation Booster, available from Actegy Limited in the UK. TM This is described in British Patent Application No. 2493904.

[0010] The device disclosed in Patent No. GB2493904A (Patent Document 3) comprises a circular disc with a pair of electrical contact pads on one side of the disc and a rocker element on the opposite side. During use, the user (or subject) places their foot on the pad, and the rocker element is in contact with the floor or ground, thereby causing the device to rock back and forth relative to the rocker element. Variable intensity electrical stimulation is then delivered to the plantar muscles of the user's foot through the pad, causing repetitive contraction and relaxation of the user's leg muscles. The advantage of the rocker element is that it allows the disc to rock back and forth (or pivot), thereby allowing the user's foot to move around the ankle joint during the electrical stimulation cycle.

[0011] However, it is recognized that the effectiveness of electrical stimulation can be significantly affected by the conductivity between the user's foot and the electrical contact pad. In extreme cases, it has been found that if the conductivity is low, the effectiveness of electrical stimulation may be minimal or even absent. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] U.S. Patent No. 5358513 [Patent Document 2] U.S. Patent No. 6615080 [Patent Document 3] UK Patent Application Publication No. 2493904 [Overview of the project] [Means for solving the problem]

[0013] An apparatus for detecting conductivity between a subject and a device for electrical stimulation of the subject is provided according to a first aspect of the present invention, and the apparatus is (i) A first electrical contact portion which is adapted to come into contact with the skin of the subject at a first location during use, (ii) A second electrical contact portion which is adapted to come into contact with the skin of the subject at a second location during use, (iii) A processor having an output connected to a first electrical contact and an input connected to a second electrical contact, (iv) Output devices coupled to the processor and The processor is configured to output an AC voltage signal to a first electrical contact and to receive a response signal from a second electrical contact, and the processor is further configured to (a) transmit an output signal to an output device in response to a received response signal when in use, the output signal corresponding to the received response signal and indicating conductivity between the device and the subject, or (b) transmit an output signal to an output device when the voltage amplitude of the response signal received by the processor is below a threshold, the output signal indicating that conductivity between the subject and the device is below a threshold.

[0014] A second aspect of the present invention provides a method for detecting conductivity between a subject and a device for electrical stimulation of the subject, and the method is as follows: (i) In the first location, the first electrical contact part is brought into contact with the skin of the subject, (ii) In the second location, the second electrical contact part is brought into contact with the subject's skin, (iii) Applying an AC voltage signal to the first electrical contact, (iv) Receiving a response signal at the second electrical contact point The processor is configured to output an AC voltage signal to a first electrical contact and to receive a response signal from a second electrical contact, and the processor is further configured to either (a) transmit an output signal to an output device in response to a received response signal when in use, the output signal corresponding to the received response signal and indicating conductivity between the device and the subject, or (b) transmit an output signal to an output device when the voltage amplitude of the response signal received by the processor is below a threshold, the output signal indicating that conductivity between the subject and the device is below a threshold.

[0015] The output device may include at least one of the following: a visual display device, an audible signal output device, a tactile signal output device, and a wireless data signal output device. The wireless data signal output device may operate on one or more wireless network protocols, such as Bluetooth® or Wi-Fi, based on the IEEE 802.11 family of standards. For example, the wireless data signal output device may include a Bluetooth® transmitter.

[0016] In one embodiment of the present invention, the output device comprises a wireless data signal output device, which may be configured to be coupled to a mobile device such as a smartphone or tablet via a wireless transmission link when in use.

[0017] Preferably, the mobile device comprises at least one of a visual display device, an audible signal output device, and a tactile signal output device. At least one of the visual display device, the audible signal output device, and the tactile signal output device is adapted to generate a user output signal in response to an output signal received by the mobile device from a processor via a wireless data signal output device.

[0018] Typically, an AC voltage signal may include a square wave signal.

[0019] Preferably, the alternating voltage signal has an amplitude of less than about 20V, more preferably less than about 10V, even more preferably less than or equal to about 5V, and most preferably an amplitude of 1V to 5V.

[0020] Typically, the threshold corresponds to the amplitude of the response signal that is less than 50% of the output alternating voltage signal, preferably less than 35% of the output alternating voltage signal, and more preferably less than 30% of the output alternating voltage signal. Most preferably, the threshold corresponds to the amplitude of the response signal that is 20% to 30% of the output alternating voltage signal. In one embodiment, the threshold may correspond to the amplitude of the response signal that is 23% to 26% of the output alternating voltage signal.

[0021] In one embodiment of the present invention, the amplitude of the output alternating voltage signal is substantially 3V, and the threshold corresponds to the amplitude of the response signal that is within the range of about 0.7V to 0.8V.

[0022] Preferably, the device is adapted to contact the skin of the subject such that the first and second electrical contacts are on different limbs of the subject at the first and second locations. More preferably, the first and second locations are on different lower limbs of the subject, and even more preferably, the first and second locations may be on different calves of the subject, and most preferably, may be on different feet of the subject. In one embodiment of the present invention, the first and second locations may be on the plantar surfaces of different feet of the subject.

[0023] A device for electrical stimulation of a subject according to a third aspect of the present invention is provided, the device comprising a device according to the first aspect and optionally any features of the first aspect, and electrical stimulation means adapted to apply an electrical stimulation voltage to the muscles of a body part of the subject in use.

[0024] The processor may have an output coupled to the electrical stimulator to enable the processor to control the electrical stimulation voltage. Alternatively, the device may further comprise another processor coupled to the electrical stimulator to control the electrical stimulation voltage.

[0025] Typically, the electrical stimulation means is adapted to stimulate the muscles of the subject's limbs. Preferably, the electrical stimulation means is adapted to stimulate the muscles of the subject's lower limbs, such as at least one of the muscles of the subject's legs and feet.

[0026] Typically, the electrical stimulation means comprises a first electrical stimulation contact surface and a second electrical stimulation contact surface. Typically, the first and second electrical stimulation contact surfaces are electrically insulated from each other. Preferably, the first and second electrical stimulation contact surfaces are adapted to contact the subject's first and second limbs, respectively, during use. In one embodiment of the present invention, the first and second electrical stimulation contact surfaces are adapted to contact the subject's first and second feet, respectively, during use.

[0027] The device may include a housing. The first and second electrical stimulation contact surfaces may be located on the external portion of the housing.

[0028] Preferably, the first and second electrical contacts are located on the external surface of the device. More preferably, the first electrical contact is located on the first electrical stimulation contact surface, and the second electrical contact is located on the second electrical stimulation contact surface. Even more preferably, the first and second electrical contacts are located within or inserted into the respective first and second electrical stimulation contact surfaces.

[0029] Preferably, at least a portion of the contact surfaces of the first and second electrical contacts protrudes outward from the plane defined by the respective first and second electrical stimulation contact surfaces. Thus, at least a portion of the contact surfaces of the first and second electrical contacts rises above the level of the respective first and second electrical stimulation contact surfaces.

[0030] Typically, the first and second electrical contacts are electrically insulated from their respective first and second electrical stimulation contact surfaces. The first and second electrical contacts may be surrounded by an electrical insulating material to electrically isolate them from their respective first and second electrical stimulation contact surfaces.

[0031] Typically, the electrical stimulation means further comprises a voltage source device electrically coupled to the first and second electrical stimulation contact surfaces and adapted to apply a voltage across the first and second electrical stimulation contact surfaces.

[0032] Preferably, the voltage source device outputs an AC voltage waveform across the first and second electrical stimulation contact surfaces. More preferably, the voltage applied across the first and second electrical stimulation contact surfaces by the voltage source device comprises a plurality of voltage pulses.

[0033] Preferably, the device further comprises a pivoting member, which is adapted to allow the device to pivot around the pivoting member in response to movement of a body part.

[0034] A fourth aspect of the present invention is provided, comprising a system including (i) an apparatus according to the first aspect or (ii) a device according to the third aspect, and a remote device, wherein the remote device comprises a remote wireless data input device and a remote output device, the output device comprises a wireless data output device, the first output signal comprises a wireless data signal emitted by the wireless data output device, the remote wireless data input device is adapted to receive the wireless data signal, and the remote output device generates a remote user output signal in response to the received wireless data signal.

[0035] A remote wireless data signal input device may operate on one or more wireless network protocols, such as Bluetooth® or Wi-Fi, based on the IEEE 802.11 family of standards. For example, if the wireless data output device includes a Bluetooth® transmitter, the remote wireless data input device may include a Bluetooth® receiver.

[0036] The remote user output signal generated by the remote device may be at least one of the following: a visual output signal, an audible output signal, and a tactile output signal.

[0037] Typically, a remote device comprises a remote device processor coupled to a wireless data input device and a remote output device, the processor generating a remote device processor output signal in response to an received wireless data signal, and the remote output device receiving the remote device processor output signal and generating a remote user output signal in response to the remote device processor output signal.

[0038] Typically, the remote device is a mobile device, and the remote user output signals generated by the mobile device are generated and displayed on the mobile device's user interface by application software on the mobile device.

[0039] As used herein, the term “mobile device” means any portable electronic device having a wireless receiver and a user interface including a display, and includes (but is not limited to) smartphones, tablets, and laptop computers.

[0040] Preferably, the remote device comprises a remote user input device adapted to receive input from a user and a remote wireless data output device, wherein in response to input received from a user on the remote user input device, the remote device is adapted to transmit a remote user input signal to the device, the device comprises a wireless data input device adapted to receive the remote user input signal transmitted by the remote wireless data output device, and the processor and / or other processors are adapted to receive the remote user input signal from the wireless data input device.

[0041] If the remote device has a user interface, the user interface may be adapted to display remote user output signals and receive user input.

[0042] Typically, a processor or other processor controls the electrical stimulation voltage in response to a received remote user input signal during use.

[0043] Preferably, the wireless data output device and the wireless data input device are each integrated into a single device such as a wireless transceiver. For example, the transceiver may include a Bluetooth® transceiver.

[0044] If the system includes a device in the second phase, the processor output signal may be transmitted by the processor to an output device and to another output device on the device, the other output device including at least one of a visual display device, an audible signal output device, and a tactile signal output device.

[0045] An advantage of the present invention recognized by the inventors is that, depending on whether the amplitude of the received voltage signal is above or below a threshold, it is possible to indicate to the user whether the level of conductivity between the subject and the first electrical contact is sufficient for electrical stimulation. This specification also provides, for example, the following: (Item 1) A device for detecting conductivity between a subject and a device for electrical stimulation of the subject, wherein the device is (i) A first electrical contact portion which is adapted to come into contact with the skin of the subject at a first location during use, (ii) A second electrical contact portion which is adapted to come into contact with the skin of the subject at a second location during use, (iii) A processor having an output connected to the first electrical contact and an input connected to the second electrical contact, (iv) Output devices coupled to the processor and The apparatus further comprises a processor configured to output an AC voltage signal to the first electrical contact and to receive a response signal from the second electrical contact, wherein the processor is further configured to (a) transmit an output signal to the output device in response to the received response signal when in use, the output signal corresponding to the received response signal and indicating the conductivity between the device and the subject, or (b) transmit an output signal to the output device when the voltage amplitude of the response signal received by the processor is below a threshold, the output signal indicating that the conductivity between the subject and the device is below a threshold. (Item 2) The apparatus according to item 1, further comprising an analog-to-digital (A / D) converter means, wherein the A / D converter means receives the response signal from the second electrical contact, converts the response signal into a digital signal, and transmits the digital signal to the processor. (Item 3) The AC voltage signal has an amplitude of less than 10V, as described in item 1 or item 2 of the apparatus. (Item 4) The apparatus according to item 3, wherein the amplitude is less than approximately 5V or equal to approximately 5V, preferably between 1V and 5V. (Item 5) The AC voltage signal includes a square wave signal, as described in any of the above items. (Item 6) The AC voltage signal has a frequency of 500 Hz to 100 kHz, and the device is one of the items described above. (Item 7) The apparatus according to any of the above items, wherein the output device comprises at least one of a visual display device, an audible signal output device, a tactile signal output device, and a wireless data signal output device. (Item 8) The apparatus according to item 7, wherein the output device comprises a wireless data signal output device, and the wireless data signal output device comprises a Bluetooth® transmitter. (Item 9) The apparatus according to any of the above items, wherein the processor transmits the output signal to the output device when the voltage amplitude of the response signal received by the processor falls below a threshold, and the threshold corresponds to the amplitude of the response signal being less than 50% of the output AC voltage signal. (Item 10) The apparatus according to item 9, wherein the threshold corresponds to the amplitude of the response signal, which is 20% to 30% of the output AC voltage signal. (Item 11) The apparatus according to any of the above items, wherein the first and second electrical contacts are adapted to contact the skin of the subject such that the first and second locations are on different limbs of the subject. (Item 12) The first and second locations are the devices described in item 11, located on different lower legs of the subject. (Item 13) A device for electrical stimulation of a subject, wherein the device comprises an apparatus described in any of items 1 to 12 and an electrical stimulation means adapted to apply an electrical stimulation voltage to the muscles of a part of the subject's body when in use. (Item 14) The device according to item 13, wherein the electrical stimulation means comprises first and second electrical stimulation contact surfaces, one of the first electrical contact portion and the first electrical stimulation contact surface is located within the other of the first electrical contact portion and the first electrical stimulation contact surface, and one of the second electrical contact portion and the second electrical stimulation contact surface is located within the other of the second electrical contact portion and the second electrical stimulation contact surface. (Item 15) The device according to item 14, wherein the first electrical contact portion is located within the first electrical stimulation contact surface, and the second electrical contact portion is located within the second electrical stimulation contact surface. (Item 16) The first electrical contact portion is electrically insulated from the first electrical stimulation contact surface, and the second electrical contact portion is electrically insulated from the second electrical stimulation contact surface. (Device as described in item 14 or item 15.) (Item 17) The device according to any one of items 14 to 16, wherein at least a portion of the first and second electrical contact portions extends above the respective first and second electrical stimulation contact surfaces. (Item 18) The device is one of the devices described in any of items 13 to 17, which is adapted to apply electrical stimulation to the subject's foot when in use. (Item 19) The device according to item 18 when subject to either item 14 or item 17, wherein the first and second electrical stimulation contact surfaces are each adapted to contact the respective sole surfaces of the subject's feet during use. (Item 20) The device according to any one of items 13 to 19, further comprising a housing, wherein the electrical stimulating means and the first and second electrical contacts are located on the outer portion of the housing. (Item 21) The electrical stimulation means is a device according to any one of items 13 to 20, which is adapted to stimulate the muscles of the limbs of the subject. (Item 22) The device according to item 21, wherein the electrical stimulation means is adapted to stimulate at least one of the muscles of the subject's leg and foot. (Item 23) A system comprising (i) an apparatus as described in item 1 or (ii) a device as described in item 30, and a remote device, wherein the remote device comprises a remote wireless data input device, a remote processor, and a remote output device, the processor transmitting the output signal to the output device in response to the received response signal, the output device comprising a wireless data output device, the output signal comprising a wireless data signal emitted by the wireless data output device, the remote wireless data input device being adapted to receive the wireless data signal and transmit the received signal to the remote processor, the remote processor outputting a remote output signal to the remote output device if the received signal is less than a threshold, the remote output signal indicating that the conductivity between the subject and the device is too low. (Item 24) The system according to item 23, wherein, in response to the remote output signal, the remote output device generates a remote user output signal indicating that the conductivity between the subject and the device is below the threshold. (Item 25) A method for detecting conductivity between a subject and a device for electrical stimulation of the subject, wherein the method is (i) In the first location, the first electrical contact part is brought into contact with the skin of the subject, (ii) In the second location, the second electrical contact part is brought into contact with the skin of the subject, (iii) Applying an AC voltage signal to the first electrical contact, (iv) Receiving a response signal at the second electrical contact portion, (V) Transmitting the response signal to the processor A method comprising a processor configured to output an AC voltage signal to the first electrical contact and to receive a response signal from the second electrical contact, wherein the processor is further configured to (a) transmit an output signal to the output device in response to the received response signal when in use, the output signal corresponding to the received response signal and indicating the conductivity between the device and the subject, or (b) transmit an output signal to the output device when the voltage amplitude of the response signal received by the processor is below a threshold, the output signal indicating that the conductivity between the subject and the device is below a threshold. [Brief explanation of the drawing]

[0046] Herein, with reference to the accompanying drawings, an embodiment of an apparatus and method for detecting conductivity is described.

[0047] [Figure 1] Figure 1 is a plan view of a device for electrical stimulation of a subject, incorporating a device for detecting conductivity. [Figure 2]Figure 2 is a side view of the device shown in Figure 1. [Figure 3] Figure 3 is a block diagram illustrating the components of a device for detecting conductivity. [Figure 4] Figure 4 is a flowchart illustrating the initialization of the software application for use with the device. [Figure 5] Figure 5 is a flowchart illustrating the update of a software application. [Figure 6] Figure 6 is a flowchart illustrating the operation of the device. [Figure 7] Figure 7 shows an embodiment of the first output from a display device for use with the apparatus. [Figure 8] Figure 8 shows an example of a second output from a display device for use with the apparatus. [Figure 9] Figure 9 is a schematic diagram showing the operation of the device during use. [Modes for carrying out the invention]

[0048] Figure 1 is a plan view of device 1 for electrical stimulation of the plantar surface of a subject's or user's foot. Device 1 comprises a housing 2 which is generally in the form of a circular disc. The housing 2 incorporates a handle 15 which allows device 1 to be easily moved by the user. Figure 2 is a side view of device 1, in which it can be seen that housing 1 has an upper surface 3 which is generally convex and a lower surface 4 which is generally convex. A power adapter socket (or power jack) 18 is located on a side section 16 of the housing into which a power adapter can be plugged to supply power to a power supply unit 25 located inside housing 2 (see Figure 3). The PSU 25 may incorporate a rechargeable power supply, such as a rechargeable battery. A socket 17 for connecting external contact pads which are positioned on other parts of the body, such as on the leg muscles, is also located on the side section 16.

[0049] The lower surface 4 includes a fixed position stopper 5 and a maximum position stopper 6. Two rocker elements 7 are located between the stoppers 5 and 6 (only one is shown).

[0050] The upper surface 3 includes two electrical contact pads 8 and 9 separated by the central display and control panel 10. The electrical contact pads 8 and 9 have a ribbed pattern formed on them, as shown on the pads 8 and 9 in the dashed lines, and both pads 8 and 9 are formed from a conductive material such as metal. For example, pads 8 and 9 may be formed from aluminum.

[0051] Electrical contact portions 51 and 52 are mounted (or inserted) within each of the pads 8 and 9, respectively. Each of the electrical contact portions 51 and 52 is electrically insulated from each of the pads 8 and 9 by an electrical insulator 53 and 54. The electrical insulators 53 and 54 may be formed from an electrically insulating material such as a plastic material. Each of the electrical contact portions 51 and 52 has a contact surface that protrudes above the surface of each of the pads 8 and 9. In this embodiment, the electrical contact portions 51 and 52 have a partially spherical surface, such as a hemispherical surface, and the partially spherical surface extends above the surface of the contact pads 8 and 9.

[0052] However, the electrical contact portions 51 and 52 may be in the form of any curved surface, such as a part of a spherical or elliptical surface, at least partially. Alternatively, or in addition, the electrical contact portions 51 and 52 may have at least partially planar surfaces that protrude above the surfaces of the contact pads 8 and 9. For example, as an alternative to being partially spherical, the electrical contact portions 51 and 52 may be at least partially spherical, elliptical, cylindrical, conical, or frustoconical.

[0053] The display and control panel 10 includes a power button 11, up and down control buttons 12 and 13, and a display 14. The power button 11, up and down control buttons 12 and 13, and the display 14 are shown with dashed lines because they are normally only visible when illuminated. The power button 11 and the up and down control buttons 12 and 13 are touch sensor areas of area 10, and are similarly shown with dashed lines.

[0054] As shown in Figure 2, when device 1 is positioned on a support surface 50 such as a floor or ground, it is pivotable around the pivot axis 19 from a resting position in which the fastener 5 and rocker element 7 are in contact with the support surface, through an intermediate pivot position in which only the rocker element 7 is in contact with the support surface (as shown in Figure 2), to a maximum pivot position in which the rocker element 7 and the maximum position fastener 6 are in contact with the support surface 50.

[0055] Figure 3 is a block diagram of a device 30 located within Device 1 for controlling and supplying the electrical stimulation cycle voltage to the footpads 8 and 9, and for detecting conductivity at the electrical contacts 51 and 52. Figure 3 also shows a power supply unit (PSU) 25 located within the housing 2, which provides power to all electrical components within Device 1, including the device 30. A Bluetooth® interface 26 provides a wireless communication interface between the device 30 and the smartphone 27 for data communication between Device 1 and the smartphone 27. A data storage server 28 located in the cloud on the internet 31 is also shown. The smartphone 27 can connect to the server 28 via an internet connection. The Bluetooth® interface 26 comprises a Bluetooth® transceiver located within Device 1 and a Bluetooth® transceiver located on the smartphone 27. The Bluetooth® interface 26 is used to enable Device 30 to communicate with the user's smartphone. This can be used to enable the processor 21 to send information to the smartphone 27 that will be displayed on the smartphone using a software application running on the smartphone, and / or to enable control signals to be sent from the smartphone to the processor to control the operation of the device 30.

[0056] The data storage server 28 may be used to download update information to device 1 via smartphone 7. For example, this may include one or more of the following: software update information, configuration update information, or data update information.

[0057] The PSU25 is coupled to the power jack 18. Therefore, device 1 can be powered via the jack 18 by either an external power source or an internal rechargeable battery. However, it is also possible for device 1 to not include an internal battery and be powered solely by an external power source via the jack 18. For example, the external power source is typically a 5V power adapter connected to a 110V or 240V main power source. The power adapter takes in the 110V or 240V AC external main power source, converts this to a 5V DC output voltage, which is then supplied to the power jack 18.

[0058] The device 30 includes a processor 21. Typically, the processor 21 is a microcontroller unit (MCU). The processor 21 controls the wave generator 22 and the pulse control unit 23 and is also coupled to the Bluetooth® transceiver on the device 1 and the control panel 10. In addition, the processor 21 has an output coupled to an electrical contact 51 and an input that receives signals from an analog-to-digital (A / D) converter 20 that receives output signals from the electrical contact 52.

[0059] The wave generator 22 generates an AC waveform from the 5V DC input from the PSU 25. This AC waveform is then boosted by the transformer 29 before being sent to the pulse control unit 23, which generates the desired voltage pulse shape and duration under the control of the processor 21. The voltage output from the pulse control unit 23 is then delivered across the foot pads 8 and 9 to provide the requested electrical stimulation to the feet.

[0060] The processor 21 is configured to output a 1.7kHz square wave AC voltage signal with an amplitude of 3V to the electrical contact 51. The A / D converter receives the voltage signal from the electrical contact 52 and converts it from an analog signal to a digital signal with a value between 0 and 1024. The conversion is directly proportional to the analog voltage signal received from the contact 52; a 3V signal is converted to a value of 1024, and a 0V signal is converted to a value of 0 (zero). This digitally converted signal is then output from the A / D converter 20 and received as an input by the processor 21.

[0061] Prior to the first use of device 1, the user downloads a software application to their smartphone 27 or another mobile device such as a tablet. The downloaded software application has a default conductivity threshold when it is first opened. Opening the software application for the first time initializes the software application and sets the default conductivity threshold (see Figure 4).

[0062] After the software application is initialized, a cloud update 65 (see Figure 5) from the cloud server 28 via the internet 31 may be used to update the software application (including an update 66 to the conductivity threshold). For example, if inspection data indicates that a different threshold is more appropriate, an update to the conductivity threshold may be necessary.

[0063] When in use, the user positions the device on a support surface 50, such as the floor in front of the chair in which the user intends to sit. If device 1 does not have an internal battery, the user also connects the power input 18 to an external power source. If device 1 has an internal battery, the user can choose to use the internal battery (in which case it is not necessary to connect the power input 18 to an external power source) or to use an external power source.

[0064] The user then uses switch 11 to turn on the device 1, which illuminates the control panel 10. The user then also opens the application software on the smartphone 27, which connects to the device 1 via the Bluetooth® interface 26.

[0065] Once device 1 is started and the software application is connected, the user can then select the desired waveform using the software application on the control panel 10 or smartphone 27.

[0066] After a waveform is selected, the application on the smartphone 27 displays a user interface 80 (see Figure 7) on the smartphone 27's touchscreen. The user interface includes a start button 81, an indication 82 for the duration of the stimulus, and an icon 83 indicating the strength of the Bluetooth® connection with device 1. The user interface 80 also includes a button 84 for increasing the stimulus intensity and a button 85 for decreasing the stimulus intensity. Points 87 on an arc-shaped graphic 86 indicate the relative intensity of the stimulus, and the numerical value of the stimulus is indicated by the number 88.

[0067] A message 89 instructing the user to place their feet on the contact pads 8 and 9 is also displayed on the user interface 80.

[0068] After the user places one foot on each of the contact pads 8 and 9 and presses the start button 81 70 (see Figure 6), the application on the smartphone 27 sends a message to the processor 21 instructing it to measure the user's moisture level 71. In response, the processor 21 outputs a 1.7 kHz square wave AC voltage 40 (see Figure 9) with an amplitude of 3 V to the electrical contact 51. When the user's foot is on the pads 8 and 9, the square wave voltage is applied to the user's foot 42 that is in contact with the pad 8. The contact 51 protrudes above the surface of the pad 8 to help ensure that there is tight contact between the electrical contact 51 and the sole surface of the user's foot 42. The square wave voltage passes through the user's body and is picked up by the other electrical contact 52 on the user's other foot 43. The voltage signal received at the electrical contact 52 is output from the electrical contact 52 to the A / D converter 20, which converts the received voltage signal into a numerical value from 0 to 1024. The conversion is directly proportional to the amplitude of the received voltage signal. Therefore, a received voltage signal of 3V is converted to a value of 1024, a received voltage signal of 0V is converted to a value of 0 (zero), and a received voltage signal of 1.5V is converted to a value of 512.

[0069] If the received voltage is 3V, this effectively means that a short circuit exists between contacts 51 and 52, and if the received voltage is 0V, this effectively means that the user is not placing both feet on pads 8 and 9.

[0070] The digital value generated by the A / D converter 20 is then output to the processor 21, and the application on the smartphone 27 receives the value from the processor 21 via a Bluetooth® wireless connection 72. The application on the smartphone 27 compares the received value to a threshold 73 to determine whether there is sufficiently high conductivity between the electrical contacts 51 and 52 and enables the electrical stimulation voltage waveform applied to the pads 8 and 9. In effect, this is a measurement of the conductivity of the user's body between the electrical contacts 51 and 52. The inventors have found that there is a correlation between the conductivity between the electrical contacts 51 and 52 and the user's moisture state, and therefore the conductivity of the user's body between the electrical contacts 51 and 52 is an indication of the user's moisture state.

[0071] Typically, a value converted from the A / D converter of 530 or greater indicates good conductivity and therefore good user moisture status. A converted value of 200 or less indicates low conductivity and therefore poor user moisture status. Thus, a typical threshold used by processors is approximately 250.

[0072] If the converted value received by the application software 72 is greater than a threshold (in this embodiment, less than or equal to 250), the application software then proceeds to initiate stimulation 76.

[0073] If the converted value received by the application software is less than or equal to a threshold (in this embodiment, less than or equal to 250), the application software displays message 90 on the user interface 80 to inform the user that their feet are too dry and advises the user to moisten their feet and / or drink some water. Message 90 also asks the user if they wish to continue the session. If the user selects "yes" 91, the stimulation is initiated 76. If the user selects "no" 92, the application software on the smartphone 27 sends another request 71 to the processor 21 to measure conductivity. The application software receives the digitized measured value from the processor 72 and compares the new value to the threshold 73. If it is still too low, the application software displays message 90 again 74.

[0074] The application software continues this loop of remeasuring the conductivity between the electrical contacts 51, 52 and comparing it to the threshold until either (i) the measured value is greater than the threshold when it is compared to the threshold 73, or (ii) the user selects "yes" 91 to continue the session. In either case (i) or (ii), then electrical stimulation is initiated 76.

[0075] The inventors understand that in some cases, electrical stimulation of a subject may not be effective when the subject's moisture level is too low. The inventors recognize that the subject's moisture level may correlate with the conductivity of the subject's body between points on the body to which the electrical stimulation is applied. When electrical stimulation is applied to the soles of the subject's feet, the conductivity between the subject's feet may be measured to indicate the subject's moisture level and whether the electrical stimulation is likely to be effective based on the measured conductivity.

[0076] The present invention has the advantage of detecting whether the conductivity of the user's body between the electrical contacts 51 and 52 is too low to produce effective electrical stimulation, and also recommending that the user moisten their feet and / or drink water to hydrate themselves.

Claims

1. A device for electrical stimulation of a subject, wherein the device is The device comprises an apparatus for detecting conductivity between the subject and the device, and the apparatus is (i) A first electrical contact portion which is adapted to come into contact with the skin of the subject at a first location during use, (ii) A second electrical contact portion which is adapted to come into contact with the skin of the subject at a second location when in use, (iii) A processor having an output coupled to the first electrical contact and an input coupled to the second electrical contact, (iv) Output devices coupled to the processor and The processor is configured to output an AC voltage signal to the first electrical contact and to receive a response signal from the second electrical contact, and the processor is further configured to either (a) transmit an output signal to the output device in response to the received response signal when in use, wherein the output signal corresponds to the received response signal and indicates the conductivity between the device and the subject, or (b) transmit an output signal to the output device when the voltage amplitude of the response signal received by the processor is below a threshold, wherein the output signal indicates that the conductivity between the subject and the device is below a threshold, and the device is The device further comprises an electrical stimulation means adapted to apply an electrical stimulation voltage to the muscles of the subject's body when in use. The electrical stimulation means comprises first and second electrical stimulation contact surfaces, The first electrical contact portion is electrically insulated from the first electrical stimulation contact surface, and the second electrical contact portion is electrically insulated from the second electrical stimulation contact surface. A device in which one of the first electrical contact portion and the first electrical stimulation contact surface is located within the other of the first electrical contact portion and the first electrical stimulation contact surface, and one of the second electrical contact portion and the second electrical stimulation contact surface is located within the other of the second electrical contact portion and the second electrical stimulation contact surface.

2. The device according to claim 1, further comprising an analog-to-digital (A / D) converter, wherein the A / D converter receives the response signal from the second electrical contact, converts the response signal into a digital signal, and transmits the digital signal to the processor.

3. The device according to claim 1 or claim 2, wherein the AC voltage signal has an amplitude of less than 10V.

4. The device according to claim 3, wherein the amplitude is less than or equal to about 5V.

5. The device according to claim 4, wherein the amplitude is 1V to 5V.

6. The device according to any one of the claims, wherein the AC voltage signal includes a square wave signal.

7. The device according to any one of the claims, wherein the AC voltage signal has a frequency of 500 Hz to 100 kHz.

8. The device according to any one of the claims, wherein the output device comprises at least one of a visual display device, an audible signal output device, a tactile signal output device, and a wireless data signal output device.

9. The device according to claim 8, wherein the output device comprises a wireless data signal output device, and the wireless data signal output device comprises a Bluetooth® transmitter.

10. The device according to any one of the claims, wherein the processor transmits the output signal to the output device if the voltage amplitude of the response signal received by the processor falls below a threshold, the threshold being the amplitude of the response signal which is less than 50% of the output AC voltage signal.

11. The device according to claim 10, wherein the threshold corresponds to the amplitude of the response signal, which is 20% to 30% of the output AC voltage signal.

12. The device according to any one of the claims, wherein the first and second electrical contacts are adapted to contact the skin of the subject such that the first and second locations are on different limbs of the subject.

13. The device according to claim 12, wherein the first and second locations are on different lower legs of the subject.

14. The device according to any one of claims 1 to 13, wherein the first electrical contact portion is located within the first electrical stimulation contact surface, and the second electrical contact portion is located within the second electrical stimulation contact surface.

15. The device according to any one of claims 1 to 14, wherein at least a portion of the first and second electrical contact portions extends above the respective first and second electrical stimulation contact surfaces.

16. The device according to any one of claims 1 to 15, wherein the device is adapted to apply electrical stimulation to the foot of a subject when in use.

17. The device according to claim 16, wherein the first and second electrical stimulation contact surfaces are each adapted to contact the respective sole surfaces of the subject's feet during use.

18. The device according to any one of claims 1 to 17, further comprising a housing, wherein the electrical stimulating means and the first and second electrical contact portions are located on the outer portion of the housing.

19. The device according to any one of claims 1 to 18, wherein the electrical stimulation means is adapted to stimulate the muscles of the limbs of the subject.

20. The device according to claim 19, wherein the electrical stimulation means is adapted to stimulate at least one of the muscles of the subject's leg and foot.

21. A system comprising a device according to any one of claims 1 to 20 and a remote device, wherein the remote device comprises a remote wireless data input device, a remote processor, and a remote output device, the processor transmitting the output signal to the output device in response to a received response signal, the output device comprising a wireless data output device, the output signal comprising a wireless data signal emitted by the wireless data output device, the remote wireless data input device being adapted to receive the wireless data signal and transmit the received signal to the remote processor, the remote processor outputting a remote output signal to the remote output device if the received signal is less than a threshold, the remote output signal indicating that the conductivity between the subject and the device is too low.

22. The system according to claim 21, wherein, in response to the remote output signal, the remote output device generates a remote user output signal indicating that the conductivity between the subject and the device is below the threshold.

23. A method for operating an apparatus for detecting conductivity between a subject and a device for electrical stimulation of the subject, wherein the method is: (i) At the first location, the first electrical contact part is brought into contact with the skin of the subject, (ii) In the second location, the second electrical contact part is brought into contact with the skin of the subject, (iii) Applying an AC voltage signal to the first electrical contact, (iv) Receiving a response signal at the second electrical contact portion, (v) Transmitting the response signal to the processor The processor is configured to output an AC voltage signal to the first electrical contact and to receive a response signal from the second electrical contact, and the processor is further configured to either (a) transmit an output signal to the output device in response to the received response signal when in use, wherein the output signal corresponds to the received response signal and indicates the conductivity between the device and the subject, or (b) transmit an output signal to the output device when the voltage amplitude of the response signal received by the processor is below a threshold, wherein the output signal indicates that the conductivity between the subject and the device is below a threshold. The device comprises the apparatus and an electrical stimulation means adapted to apply an electrical stimulation voltage to the muscles of a part of the subject's body when in use. The electrical stimulation means comprises first and second electrical stimulation contact surfaces, The first electrical contact portion is electrically insulated from the first electrical stimulation contact surface, and the second electrical contact portion is electrically insulated from the second electrical stimulation contact surface. A method wherein one of the first electrical contact portion and the first electrical stimulation contact surface is located within the other of the first electrical contact portion and the first electrical stimulation contact surface, and one of the second electrical contact portion and the second electrical stimulation contact surface is located within the other of the second electrical contact portion and the second electrical stimulation contact surface.

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