Device and method for inducing vasoconstriction by electrical stimulation

Abstract

A device configured to be worn on a hand or foot, comprising: a plurality of electrodes arranged to be positioned on one or more respective phalanges when the device is attached to the hand or foot; a support structure configured to attach the device to a hand or a foot and hold the plurality of electrodes; and a controller configured to control application of signals to the plurality of electrodes. A feedback sensor may be provided and positioned on the finger to monitor characteristics of the underlying tissue.

Description

Technical Field

[0001] The present invention relates to a wearable device configured to apply electrical stimulation to the autonomic (sympathetic) nervous system to achieve targeted vasoconstriction. Background Art

[0002] One of the widely observed side effects in chemotherapy treatment is chemotherapy-induced peripheral neuropathy (CIPN). CIPN may manifest as tingling or numbness in the hands and feet, pain in the hands and feet, and loss of function after chemotherapy, leading to a worse quality of life.

[0003] The toxicity of chemotherapy drugs is thought to cause nerve damage, leading to CIPN. This is a cumulative effect, as the level of toxicity increases with each chemotherapy treatment. This often leads to a reduction or cessation of chemotherapy treatment, resulting in poorer treatment outcomes. CIPN is thought to affect the majority of patients undergoing chemotherapy treatment, meaning that addressing this condition is an urgent unmet clinical need.

[0004] Current methods for treating CIPN are not well tolerated by patients and are not easily applied by healthcare professionals. One existing solution is cold therapy that causes vasoconstriction. However, due to the very low temperatures involved, such devices have poor patient comfort and tolerance. Due to the length of some chemotherapy courses, cold inserts must be replaced regularly, or several devices are required, which is time-consuming for healthcare professionals. Such devices are also known to cause thermal injuries such as frostbite. Summary of the invention

[0005] According to a first aspect of the present invention, a device configured to be worn on a hand or foot is described, the device comprising: a plurality of electrodes arranged to be positioned on one or more corresponding phalanges when the device is attached to the hand or foot; a support structure configured to attach the device to the hand or foot and hold the plurality of electrodes; and a controller configured to control the application of signals to the plurality of electrodes.

[0006] Each of the plurality of electrodes may be arranged to be positioned on the proximal phalanx of the corresponding finger. Alternatively, each of the plurality of electrodes may be arranged to be positioned on the middle phalanx of the corresponding finger. Alternatively, each of the plurality of electrodes may be arranged to be positioned on the distal phalanx of the corresponding finger. Alternatively, each of the plurality of electrodes may be arranged to be positioned on the proximal phalanx and the middle phalanx of the corresponding finger. Alternatively, each of the plurality of electrodes may be arranged to be positioned on all phalanges of the corresponding finger. The device may also include one or more reference electrodes positioned on the hand or foot away from the fingers or toes. One or more reference electrodes may be positioned on the palm of the hand. One or more reference electrodes may be positioned on the back of the hand. One or more reference electrodes may be positioned on the sole of the foot. One or more reference electrodes may be positioned on the instep of the foot.

[0007] The device may further include a sensor held by the support structure, wherein the sensor is positioned on the finger and configured to monitor a property of underlying tissue.

[0008] The sensor may include a photoplethysmographic sensor configured to output a signal to the controller.The controller may be configured to derive a peripheral perfusion index in the underlying tissue based on the signal.

[0009] The sensor may include a peripheral autonomic surface potential sensor configured to measure activity of autonomic nervous tissue underlying the sensor.

[0010] The sensor may include a surface electromyography sensor configured to measure activity of somatic neural tissue underlying the sensor.

[0011] The controller may be configured to dynamically adjust characteristics of the signals applied to the plurality of electrodes based on signals received from the sensors.

[0012] The device may include a plurality of sensors, each of the plurality of sensors being positioned on a respective finger. Alternatively, some subset of the fingers may have a corresponding sensor.

[0013] The controller may be configured to periodically apply a signal to the plurality of electrodes at a 50% duty cycle.

[0014] The device may further comprise an auxiliary electrode arranged to be positioned on the forearm or foreleg when the device is attached to the hand or foot. The auxiliary electrode may be positioned to provide an analgesic effect when stimulation is applied.

[0015] The device may include an article of clothing configured to be worn on the hand, and optionally, wherein the article of clothing is a glove or mitt. Configuring the article of clothing as a glove may be advantageous because the patient retains a degree of dexterity while the electrical stimulation is applied, and is therefore able to continue to perform some tasks during treatment.

[0016] The apparatus may comprise an article of clothing configured to be worn on a foot, and optionally wherein the article of clothing is a sock or a shoe.

[0017] According to a second aspect of the invention, a method of inducing vasoconstriction in a peripheral nerve using electrical stimulation is described, the method comprising: attaching a device comprising a plurality of electrodes to a hand or foot of a patient such that each electrode is positioned over one or more corresponding phalanges of the patient; applying a series of test signals using the plurality of electrodes to calibrate a perception threshold at which the patient perceives the test signals; and applying a therapeutic signal using the plurality of electrodes that is below the perception threshold established for the patient.

[0018] The method may also include: monitoring a level of vasoconstriction using one or more sensors; and adjusting one or more parameters of the therapy signal based on the monitored level of vasoconstriction.

[0019] The device may include an auxiliary electrode arranged to be positioned on a forearm or foreleg when the device is attached to a hand or foot of the patient, and the method may further include applying one or more auxiliary signals using the auxiliary electrode after applying the therapeutic signal to induce analgesic and / or massage effects on the underlying tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to enable a more complete understanding of the general concepts set forth in the foregoing sections, embodiments thereof will be described with reference to the accompanying drawings, in which:

[0021] Figure 1 A device in the form of a glove with an integrated control system is shown;

[0022] Figure 2 Systems according to some other embodiments are shown wherein the control system is external to the device;

[0023] Figure 3 shows an apparatus including a monitoring sensor according to a further embodiment;

[0024] Figure 4a is a graph showing results from a prototype device with a single electrode attached to a fifth finger;

[0025] Figure 4b shows a series of graphs illustrating experimental results with electrodes positioned on the proximal phalanx;

[0026] Figure 4c A series of graphs are shown showing experimental results for different positions of the test electrodes;

[0027] Figure 5 shows a device comprising an elongated electrode and an optional auxiliary electrode according to a further embodiment;

[0028] Figure 6 shows a device according to a further embodiment, in which end portions of the finger sections are omitted;

[0029] Figure 7 Schematically shows the control Figure 1-Figure 3 , Figure 5-Figure 6 and Figure 8 any electronic system in the operation of a device;

[0030] Figure 8 shows a device in the form of a sock according to a further embodiment; and

[0031] Fig. 9 is a flow chart illustrating an exemplary method for applying therapy for inducing vasoconstriction in a peripheral nerve using electrical stimulation. DETAILED DESCRIPTION

[0032] refer to Figure 1 , a device 100 in the form of a glove is shown. The device 100 includes a support structure 102 that allows it to be attached to a user's hand. The device 100 also includes a plurality of electrodes 104-1 to 104-5 (generally indicated as 104). Each electrode 104 is located in a corresponding finger of the glove to be positioned on the corresponding finger of the user when the user wears the glove. The electrode 104 can be positioned on the upper side of each glove finger to contact the upper surface of each finger, or positioned on the lower side of each glove finger to contact the lower surface of each finger. Alternatively, each electrode 104 can have an annular shape or a partial annular shape to partially or completely wrap the corresponding finger.

[0033] The electrodes 104 may extend longitudinally along the length of the user's finger, such as Figure 1 As shown. Alternatively, the electrodes 104 can be positioned transversely to the user's fingers. In such an arrangement, each electrode 104 can partially wrap around the corresponding finger to cover both the inside and outside of the finger.

[0034] exist Figure 1 In the illustrated embodiment, electrodes 104-1 to 104-5 are each positioned on the proximal phalanx of a corresponding finger. In some other embodiments described below, electrodes 104-1 to 104-5 may be positioned on the middle phalanx or the distal phalanx or extend over two or more phalanxes.

[0035] In addition to these, reference electrode 105 is also placed on / around the palm or wrist. Each of electrodes 104-1 to 104-5 may share a common reference electrode 105. Alternatively, multiple reference electrodes 105 may be provided so that each electrode 104 has a corresponding reference electrode 105. Reference electrode 105 may extend longitudinally along the length of the user's palm, such as Figure 1 As shown. Alternatively, the reference electrode 105 may be positioned across the palm of the user (transverse to the direction of the fingers). Generally, the reference electrode(s) 105 are positioned away from the fingers.

[0036] It has been observed that placing the reference electrode 105 on the palm of the user has the greatest vasoconstrictive effect. However, the reference electrode 105 may alternatively be positioned on the back of the user's hand.

[0037] Electrodes 104-1 to 104-5 may be the anodes of the system, while the reference electrode may be the cathode.With this arrangement, the signal applied to electrode 104 stimulates along the user's finger.

[0038] The device 100 also includes a control system 106 which, in this embodiment, is supported on a wrist portion of the glove.

[0039] The support structure 102 can be a glove with an elongated wrist portion having a modified area for holding electrodes 104 and a modified area or pocket for holding a control system 106. The support structure 102 can include holes or other access points to allow adjustment or replacement of each electrode 104. In some other embodiments, the support structure 102 can include a frame or mesh structure. This can allow increased airflow to the hand compared to a glove. The electrodes 104, 105 and the control system 106 can be held by an adjustable and / or elastic band. Alternatively or additionally, the electrodes can have an adhesive portion for securing the electrodes to the user's skin.

[0040] The control system 106 may include a power supply, a pulse generator, and a processing unit for controlling the application of electrical signals to the electrodes 104 (optionally in conjunction with feedback circuitry). To this end, each of the electrodes 104 may have a separate connection to the control system 106. In some embodiments, the reference electrode may be located directly below the control system and / or may be integral to the control system. The control system may also include information about Figure 6 The other elements are described in more detail.

[0041] Figure 2A system 200 is shown according to some other embodiments, wherein the control system 106 is located external to the device 202. The device 202 includes a hub 204 into which the electrodes 104 and the reference electrode 105 are all connected. The hub 204 can in turn connect and disconnect with the control system 106 via ports on the hub 204 and / or the control system 106. This arrangement reduces the complexity of the device 202 and allows the control system 106 to be used with different devices 202, which means that fewer control systems 106 are needed.

[0042] exist Figure 1 and Figure 2 In both embodiments, the electronic components of the device 100, 202 can be removed from the support structure 102, which allows the support structure to be cleaned. Alternatively, some or all of the electronic components can be embedded in the support structure 102 or otherwise permanently attached to the support structure 102. The support structure 102 can be made of a resilient material to allow it to be used with patients with hands of different sizes. Alternatively or additionally, the device 100, 202 can have a variety of different sizes.

[0043] refer to Figure 3 , shows a device 300 according to another embodiment. The device 300 includes Figure 1 The device 300 also includes the same arrangement of electrodes 104, reference electrodes 105, and control system 106 as disclosed in the embodiments of FIG. 1 . In addition, the device 300 includes at least one sensor 302-1 to 302-5 (generally indicated as 302) held by the support structure 102. Each sensor 302 is arranged to be positioned on a finger and is configured to monitor a property of the underlying tissue.

[0044] although Figure 3 Sensors 302 are shown positioned on each finger, but in some embodiments, only a subset of the sensors shown may be present. In some embodiments, only a single sensor may be used. A variety of different sensing technologies may be used for sensor 302. In some embodiments, the sensor may include a photoplethysmography (PPG) sensor configured to output a signal to the controller system 106. The PPG sensor is positioned on the underside of the glove to contact the pad of each finger when the patient wears the glove. The control system 106 is configured to receive signals from the PPG sensor and derive an indication of peripheral perfusion in the underlying tissue (such as a peripheral perfusion index - PPI) based on the received optical signal. The PPI gives a measure of blood flow in the finger.

[0045] In some other embodiments, the sensors include peripheral autonomous surface potential sensors. These sensors are configured to measure potentials indicative of activity of autonomic nervous tissue beneath the sensors. The control system 106 receives signals from the peripheral autonomous surface potential sensors and is configured to determine a measure of blood flow in the finger.

[0046] In some other embodiments, the sensors include surface electromyography sensors. These sensors are configured to measure the activity of somatic neural tissue underlying the sensors.

[0047] In some embodiments, the electrodes 104 used to apply stimulation to the fingers can also be used as sensors. In the above embodiments, the peripheral autonomous surface potential sensor or surface electromyography sensor includes electrodes. These electrodes can also be electrodes 104 used to stimulate the fingers. As described below with reference to Figure 4, stimulation is applied periodically. During the period when no signal is applied to the electrodes 104, they can be used as sensors.

[0048] Measuring the current blood flow in the finger when electrical stimulation is applied to the electrodes allows real-time monitoring of the effectiveness of the treatment. Information from the sensor can also be used as a feedback mechanism to dynamically change the intensity, frequency and / or periodicity of the signal being applied to the electrodes to achieve the highest sustained level of vasoconstriction during a course of chemotherapy.

[0049] Figure 4a 400 is a graph showing results from a prototype device with a single electrode attached to the fifth finger and a reference electrode attached to the palm. The electrodes extend over both the proximal and middle phalanx. A PPG sensor is placed on the tip of the fifth finger. Values ​​for the peripheral perfusion index are derived from the optical signals received from the PPG sensor during testing. A 30 second adaptation period is given before any signal is applied. Electrical stimulation is then applied for 10 seconds, followed by a 10 second off period, repeated periodically. The frequency of the applied signal is ~50 Hz, the current is 15 mA, and the pulse width is ~100 μs.

[0050] It can be seen that during the initial period of electrical stimulation, the PPI drops sharply to about 20% of the pre-stimulation value. When the stimulation is removed, the PPI rises during the period without stimulation, but drops again when the stimulation is reapplied. As can be seen from the graph 400, the periodic application of electrical stimulation for 10 seconds at a duty cycle of 50% results in an average PPI of about 40% of the pre-stimulation value during the test period. This result shows that significant vasoconstriction can be achieved by targeted application of periodic electrical signals on the phalanges. A possible mechanism is by inhibiting local nitric oxide release, thereby activating local autonomic (sympathetic) responses.

[0051] Figure 4bThe following contains a series of graphs showing first the stimulation curve and then the root mean square PPG signal versus time for a number of experiments. These results are obtained using Figure 3 The device shown is obtained with electrodes 104 positioned on the proximal phalanx of the fingers and a reference electrode positioned on the palm. The PPG sensor 302 is positioned in contact with the pad of each finger. After the device 300 is attached to the user, an extended stabilization period occurs in which no signal is applied.

[0052] The electrical stimulus was then applied periodically for 20 seconds with a duty cycle of 50%. The frequency of the applied signal was ~80 Hz and the pulse width was ~180 μs. The first 20 seconds of the measurement period (in which no signal was applied) was used as a baseline, and the signal was normalized relative to the baseline when plotted, allowing comparison of responses between fingers. As in Figure 4b As can be seen in the first plot in , when starting or resuming stimulation, the device has a linear ramp up over a period of 3 s. When pausing, the device will stop stimulation by a linear ramp down over a period of 1 s.

[0053] Six different configurations are then shown, representing results from the thumb, index finger, middle finger, ring finger, and pinky finger of the user's left hand. The last configuration shows results from the user's big toe (see below). Figure 8 ). It can be seen that when the stimulation signal is applied, the PPG signal intensity drops significantly, which is caused by the massive vasoconstriction in the peripheral nerves of the finger pad. These tests demonstrate the clear ability to induce vasoconstriction and maintain this reduced blood flow for an extended period of time.

[0054] During these tests, the inventors noticed that it became difficult to hold the PPG probe on the thumb as the thumb deformed, as evident in a gradual degradation of the vasoconstriction effect detected in Configuration 1 .

[0055] Figure 4c The diagram contains a series of graphs showing first the stimulation curves and then the root mean square PPG signal versus time for a number of experiments in which different positions of the electrode 104 were tested. Figure 4b Same as described. After the device is attached to the user, an extended stabilization period with no signal applied also occurs. The first 20 seconds of the measurement period (in which no signal is applied) are again used as the baseline, with respect to which the signal is normalized when plotted.

[0056] Figure 4c Configuration 2a in includes an electrode positioned on the proximal phalanx of the left index finger, a reference electrode positioned on the palm and a PPG sensor on the left index finger pad. Figure 4cConfiguration 2b in includes an electrode positioned on the middle phalanx of the left index finger, a reference electrode positioned on the palm and a PPG sensor on the left index finger pad. Figure 4c Configuration 2c in includes an electrode positioned on the distal phalanx of the left index finger, a reference electrode positioned on the palm and a PPG sensor on the left index finger pad.

[0057] It can be seen that the largest drop in the PPG signal during stimulation was observed when the electrode was positioned on the proximal phalanx, and in general the effect appeared to be more pronounced in the case of stimulation at the proximal and middle phalanx. However, a sustained long-term reduction in the PPG signal was observed in all cases, which was caused by sustained vasoconstriction and reduced blood flow in the fingertips.

[0058] refer to Figure 5 , a device 500 according to another embodiment is shown. The device 500 includes an elongated electrode 104 extending along all phalanges of a finger. The electrode 104 is otherwise identical to those previously described. As previously described, the reference electrode 105 is positioned on the palm (or back of the hand). The electrode is connected to and controlled by a control system 106, which is similar to the control system 106 already described. In addition, the device 500 may optionally include an auxiliary electrode 502, which is supported on an elongated wrist portion of the glove to be positioned on the patient's forearm when the patient wears the glove. The position of the auxiliary electrode 502 is such that applying stimulation will cause vasodilation of the tissue below. The auxiliary electrode may be a standard TENS electrode. Therefore, the auxiliary electrode 502 is not used during a chemotherapy course, but the auxiliary electrode 502 may be activated after treatment to increase peripheral blood flow, thereby causing an analgesic effect or a massage effect.

[0059] refer to Figure 6 , shows a device 600 according to another embodiment. The device 600 includes Figure 1 The same arrangement of electrodes 104, reference electrodes 105, and control system 106 disclosed in the embodiment of . However, the end portions of the fingers of the gloves are removed so that when the patient wears the device 600, the patient's fingertips will be exposed. This allows the device 600 to be used in combination with existing PPI monitors such as pulse oximeters. The design can also allow patients to perform tasks more flexibly while undergoing chemotherapy treatment.

[0060] Figure 7 Schematically illustrated is an electronic system 700 for controlling the operation of the previously described device. The electronic system 700 includes a controller 702, the previously described electrodes 104, (one or more) reference electrodes 105, one or more of the previously described monitoring sensors 302, and a power supply 704. Optionally, the electronic system may also include a display 706, a monitoring station 708, and / or a wireless transceiver 710.

[0061] The controller 702 is configured to control the operation of other components of the electronic system 700. The controller 702 may be, for example, a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), etc. Alternatively, the controller 702 may include dedicated processing hardware, such as a RISC processor or programmable hardware with embedded firmware. The controller 702 may include multiple processors. The controller 702 may also include a memory, such as a program memory storing program code (e.g., software or firmware). The program memory may be, for example, a non-volatile memory, such as a read-only memory (ROM), a flash memory, or a magnetic drive memory.

[0062] The display 706 may be a standard LCD display or a touch-sensitive display based on capacitive or resistive sensing technology. The display 706 may be removably or permanently attached to the support structure 102 of the device. In the case where the device is a glove, the display 706 may be positioned on the elongated wrist portion of the glove so that the display 706 can be easily viewed by the patient without interfering with the chemotherapy treatment or the electrical stimulation provided by the device. The power source 704 may be any suitable type of battery and may provide power to all other elements of the electronic system 700. The power source 704 may also be maintained on or in the support structure 102.

[0063] The electronic system 700 may also optionally include a wireless transceiver 710 for communicating with an external device 712. The wireless transceiver 710 includes a network interface necessary for communicating via 3G, 4G, 5G, Bluetooth, WiFi, Zigbee, or any combination of these protocols, and may also include an antenna. The wireless transceiver 710 may communicate directly with the external device 712, or the communication may be routed via an intermediate device, a router, a server, or a base station. The external device 712 may be a smart phone, a tablet computer, a PDA, or other mobile computing device. The external device 712 may be assigned to a patient or a patient's doctor or other medical professional. The external device 712 may run an application (app) or other software to display information related to the operation of the electronic system 700. Other information about the patient's chemotherapy (such as the duration of the current treatment, the remaining time) may be integrated into the app. The information received from the monitoring sensor 302 may be displayed on a display of the external device 712. The app or other software on the external device 712 may also allow control of the electronic system 700 to, for example, start, stop and / or pause electrical stimulation or change a parameter of the applied signal, such as current or periodicity (duty cycle). The external device 712 also includes a memory (not shown) that can be used to record any information received from the monitoring sensor 302 for subsequent review or onward transmission.

[0064] In some embodiments, the controller 702 and the power supply 704 may be combined in Figure 1 , Figure 2 , Figure 5 and Figure 6 The display 706 and the wireless transceiver 710 (if present) may also be part of the control system 106. The electrodes 104 and the monitoring sensors 302 (if present) must be located away from the control system 106 so that these components can be located on the user's finger.

[0065] In some other embodiments, the electronic system 700 includes a monitoring station 708 to which the controller 702 can be connected. The monitoring station 708 is external to the device and can include a computer terminal. When the device is in use, the monitoring station 708 can receive information from the monitoring sensor 302. This can allow a doctor, nurse, or other medical professional to observe the effects of electrical stimulation in real time. In some embodiments, the monitoring station 708 can issue instructions to the controller 702 to change the parameters of the applied signal, such as current or periodicity (duty cycle). This can be done automatically due to feedback from the monitoring sensor 302 to maximize the reduction of peripheral blood flow, or to keep peripheral blood flow at or within defined limits.

[0066] In use, the controller 702 controls the power supply 704 to apply electrical signals to the electrodes 104 according to a preset program. The preset program may be stored in a memory on the controller, in a separate memory (not shown) forming part of the electronic system 700, or on the monitoring station 708.

[0067] The controller 702 receives feedback signals from the monitoring sensor 302 and controls the display of the information on the display 706 (if present). The feedback information can be transmitted to the monitoring station 708 for display and / or storage. The feedback information can also be transmitted to the external device 712 via the wireless transceiver 710 for display and / or storage. The controller 702 can receive instructions from the monitoring station 708 or the external device 712 to change one or more parameters of the applied signal.

[0068] refer to Figure 8 , shows a device 800 according to a further embodiment. The device 800 comprises a sock or other clothing arrangement worn on a patient's foot. The device 800 comprises a support structure 802 that allows it to be attached to a user's foot.

[0069] The device 800 includes a plurality of electrodes 104. Each electrode 104 is located in a corresponding toe of a sock to be positioned on a corresponding toe of the user when the user wears the sock. The electrode 104 may be positioned on the upper side of each toe region to contact the upper surface of each toe, or positioned on the lower side of each toe region to contact the lower surface of each toe. Alternatively, each electrode 104 may have an annular shape or a partial annular shape to partially or completely wrap the corresponding toe. In addition to these, a reference electrode 105 is also placed on / around the sole of the foot. In some alternative embodiments, the reference electrode 105 is positioned on the top of the foot portion of the sock or on the ankle portion of the sock. In general, (one or more) reference electrodes 105 are positioned away from the toes.

[0070] The apparatus 800 also includes the control system 106 as previously described, which in this embodiment is supported on top of the foot portion of the sock. Figure 8 The control system 106 in may include some elements of the electronic system 700 as previously described, and may be capable of connecting to a monitoring station 708 and / or communicating with an external device 712, as previously described.

[0071] The support structure 802 may be a sock having a modified area for holding the electrodes 104. The support structure 802 may include holes or other access points to allow each electrode 104 to be adjusted or replaced.

[0072] As with the glove embodiment described above, Figure 8 The electrodes 104 in the sock embodiment of the device 800 are positioned to apply electrical stimulation directly to the phalanges (in this case, the phalanges of the toes). Applying the electrical signal in this manner causes vasoconstriction of the blood vessels in the toes, which reduces the accumulation of toxicity caused by the chemotherapy drugs in the toes and leads to a reduction in nerve damage. The electrodes 104 can also act as sensors for determining the activity of the underlying neural tissue to monitor the effectiveness of the electrical stimulation and act as feedback for changing the electrical stimulation when necessary. In some other embodiments, one or more of the toe segments of the device 800 may be additionally provided with a PPG sensor to independently monitor blood flow and allow PPI to be derived. Alternatively, the end portion of one or more of the toe segments may be omitted to allow a separate PPG sensor to be attached to the toe.

[0073] The device 800 may also include an auxiliary electrode (not shown) supported by an elongated ankle portion (not shown) of the sock so that the auxiliary electrode is positioned on the patient's foreleg. As previously mentioned, the auxiliary electrode is not used during the chemotherapy treatment course, but may be employed after treatment to provide analgesia or massage effects.

[0074] Although the device 800 has been shown as having a separate section for each toe, the device 800 may alternatively include a single interior space in which the electrodes 104 are positioned so that they can be accurately placed on the patient's toes. In addition, although the device 800 is depicted as a sock having a separate section for each toe, the device may alternatively take the form of a slipper or shoe.

[0075] Reference again Figure 4b , the experimental results obtained by applying a signal to the hallux (big toe) are shown in Figure 6. In this experiment, the electrode was positioned on the proximal phalanx of the big toe, and the PPG sensor was attached to the toe pad. It can be seen that using this device it is possible to obtain significant and sustained vasoconstriction in the toe.

[0076] Fig. 9 is a flow chart showing an exemplary method for applying a treatment for inducing vasoconstriction in peripheral nerves using electrical stimulation. The treatment can be applied concurrently with a chemotherapy course, i.e., during the administration of a chemotherapy drug, with the goal of reducing the accumulation of peripheral neurotoxicity during chemotherapy that may lead to peripheral neuropathy.

[0077] The process begins at step 900 by attaching a device comprising a plurality of electrodes to a patient's hand or foot such that each electrode is positioned over one or more corresponding phalanges of the patient. The device may be a reference Figure 1-Figure 3 , Figure 5 , Figure 6 or Figure 8 Any of those devices described.

[0078] At step 902, a series of test signals are applied using a plurality of electrodes to calibrate the patient's perception threshold for perceiving the test signals. Ideally, the level of electrical signals used during treatment is imperceptible to the user in most circumstances, both to increase comfort and to improve uptake of the treatment. Each patient will have a different perception threshold, so it is necessary to establish a calibrated perception level for each patient prior to treatment.

[0079] At step 904, a therapy signal is applied using a plurality of electrodes, the therapy signal being below a perception threshold established for the patient.

[0080] At an optional additional step 906, the level of vasoconstriction is monitored using one or more sensors. These sensors may be any of the sensors 302 previously described. At an optional additional step 908, one or more parameters of the therapeutic signal are adjusted based on the monitored level of vasoconstriction. The adjustment of the therapeutic signal is performed within predetermined limits and also takes into account the perception threshold of the individual patient. At an optional additional step 910, one or more auxiliary signals are applied using auxiliary electrodes to induce an analgesic effect and / or a massage effect on the underlying tissue. This step is performed after the therapeutic signal is completed.

[0081] Reference numerals

[0082] 100 devices

[0083] 102 Support structure

[0084] 104 Electrodes

[0085] 104-1 First electrode, etc.

[0086] 105 Reference electrode

[0087] 106 Control System

[0088] 200 Systems

[0089] 202 Equipment

[0090] 204 Hub

[0091] 300 devices

[0092] 302 Sensor

[0093] 302-1 First sensor, etc.

[0094] 400 Graph

[0095] 500 devices

[0096] 502 auxiliary electrode

[0097] 600 devices

[0098] 700 Electronic Systems

[0099] 702 Controller

[0100] 704 Power Supply

[0101] 706 Display

[0102] 708 Monitoring Station

[0103] 710 Wireless Transceiver

[0104] 712 External Devices

[0105] 800 devices

[0106] 802 Support structure

Claims

1. A device configured to be worn on a hand or foot, the device comprising: a plurality of electrodes arranged to be positioned on one or more corresponding phalanges when the device is attached to a hand or foot; a support structure configured to attach the device to a hand or foot and to hold the plurality of electrodes; as well as A controller is configured to control application of signals to the plurality of electrodes.

2. The device according to claim 1, wherein: Each of the plurality of electrodes is arranged to be positioned on a proximal phalanx of a corresponding finger.

3. The device according to claim 1, wherein: Each of the plurality of electrodes is arranged to be positioned on a middle phalanx of a corresponding finger.

4. The device according to claim 1, wherein: Each of the plurality of electrodes is arranged to be positioned on a distal phalanx of a corresponding finger.

5. The device according to claim 1, wherein: Each of the plurality of electrodes is arranged to be positioned on a proximal phalanx and a middle phalanx of a corresponding finger.

6. The device according to claim 1, wherein: Each of the plurality of electrodes is arranged to be positioned on all phalanges of a corresponding finger.

7. A device according to any preceding claim, further comprising one or more reference electrodes located on the hand or foot remote from the fingers or toes.

8. The apparatus of any preceding claim, further comprising a sensor held by the support structure, wherein: The sensor is positioned on a finger and is configured to monitor a property of tissue underlying the finger.

9. The device according to claim 8, wherein: The sensor includes a photoplethysmographic sensor configured to output a signal to the controller.

10. The device according to claim 9, wherein: The controller is configured to derive a peripheral perfusion index in the underlying tissue based on the signal.

11. The device according to claim 8, wherein: The sensor includes a peripheral autonomic surface potential sensor configured to measure activity of autonomic nervous tissue underlying the sensor.

12. The device according to claim 8, wherein: The sensor comprises a surface electromyography sensor configured to measure activity of somatic neural tissue underlying the sensor.

13. The apparatus according to any one of claims 8 to 12, wherein: The controller is configured to dynamically adjust characteristics of signals applied to the plurality of electrodes based on signals received from the sensor.

14. The apparatus according to any one of claims 8 to 12, wherein: The apparatus includes a plurality of sensors, each of the plurality of sensors being positioned on a respective finger.

15. Apparatus according to any one of the preceding claims, wherein: The controller is configured to periodically apply a signal to the plurality of electrodes at a 50% duty cycle.

16. Apparatus according to any one of the preceding claims, wherein: The device further comprises an auxiliary electrode arranged to be positioned on the forearm or foreleg when the device is attached to the hand or foot.

17. Apparatus according to any one of the preceding claims, wherein: The apparatus comprises an article of clothing configured to be worn on a hand, and optionally wherein the article of clothing is a glove or a mitt.

18. The apparatus according to any one of claims 1 to 16, wherein: The apparatus comprises an article of clothing configured to be worn on a foot, and optionally wherein the article of clothing is a sock or a shoe.

19. A method of inducing vasoconstriction in a peripheral nerve using electrical stimulation, the method comprising: attaching a device comprising a plurality of electrodes to a hand or foot of a patient such that each electrode is positioned over one or more corresponding phalanges of the patient; applying a series of test signals using the plurality of electrodes to calibrate a perception threshold of the patient to perceive the test signals; as well as A therapy signal is applied using the plurality of electrodes, the therapy signal being below the perception threshold established for the patient.

20. The method according to claim 19, further comprising: monitoring the level of vasoconstriction using one or more sensors; as well as One or more parameters of the therapy signal are adjusted based on the monitored level of vasoconstriction.

21. The method according to claim 19 or 20, wherein: The device includes an auxiliary electrode, which is arranged to be positioned on the forearm or foreleg when the device is attached to the patient's hand or foot. The method also includes applying one or more auxiliary signals using the auxiliary electrode after applying the therapeutic signal to induce analgesic and / or massage effects on the underlying tissue.

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