Percutaneous vagus nerve stimulation

Abstract

An example system includes: a collar; a first stimulation electrode array positioned on the collar and configured to deliver stimulation therapy to a patient; a second stimulation electrode array positioned on the collar and configured to deliver stimulation therapy to the patient; a sensor array positioned on the collar and configured to detect one or more features indicative of laryngeal muscle activity of the patient; and a controller configured to control stimulation therapy to be delivered via the first stimulation electrode array and the second stimulation electrode array.

Description

[0001] This application claims the benefit of and priority to U.S. Patent Application No. 18 / 469,854, filed September 19, 2023, which claims the benefit of U.S. Provisional Application No. 63 / 478,452, filed January 4, 2023, and U.S. Provisional Application No. 63 / 376,515, filed September 21, 2022. The entire contents of each application are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to devices and techniques for performing transcutaneous vagus nerve stimulation of a patient. Background Art

[0003] Electrical stimulation of the vagus nerve has been shown to be useful for a variety of purposes. Vagus nerve stimulation (VNS) has been shown to reduce the volume of cerebral infarction and improve neurological scores in many animal studies, including those performed on rats with cerebral ischemia. In addition, VNS also aids the recovery period after stroke by improving forelimb motor function in rats by almost two times compared to controls. Along with motor function, clinical studies have also shown that VNS has successfully improved sensory function in the forelimbs.

[0004] There is growing evidence that VNS has central and peripheral anti-inflammatory effects on the progression of ischemic damage in stroke patients. These effects are mediated through both the afferent and efferent pathways of the vagus nerve. The afferent pathway acts by stimulating the locus coeruleus, leading to activation of the hypothalamic-pituitary-adrenal (HPA) axis and subsequent cortisol release. Summary of the invention

[0005] Non-invasive VNS has been shown to downregulate inflammatory cytokines and reduce infarct growth and / or volume caused by stroke. However, current technology for non-invasive VNS leaves too much room for treatment error, which may render the technology therapeutically unreliable. Some current technology for non-invasive VNS may rely on manually applying stimulation electrodes over the vagus nerve in the neck region and / or do not provide feedback about the attempted VNS, which may result in ineffective treatment.

[0006] In general, the present disclosure relates to devices, systems, and techniques for performing transcutaneous VNS, for example, stimulating one or more vagus nerves via electrodes arranged in a collar that, when secured around the patient's neck, will be positioned over the left and right cervical vagus nerves. The collar may also include a sensor array for detecting one or more parameters indicating whether the one or more vagus nerves are being stimulated and an indicator for indicating to a caregiver whether the vagus nerve is being stimulated. As described herein, the collar arranged with the electrodes and feedback may enable a caregiver to apply with a reduced skill set and required training compared to existing solutions, and may allow a relatively less skilled person to successfully stimulate the vagus nerve and do so quickly and effectively. Additionally, the bilateral stimulation electrode array may provide multiple potential stimulation zones, which may greatly increase the chances of successful stimulation based on the initial fixation of the collar to the patient. For example, the collar and associated technology may facilitate rapid provision of consistent, effective, and / or user-friendly VNS, such as by an emergency medical technician (EMT) or any other caregiver along a patient's acute and / or chronic care pathway, which would be of great assistance in treating patients suffering from stroke, TBI, and / or other detrimental conditions driven by inflammation or other disease states that would benefit from VNS, and may improve patient outcomes, reduce length of hospital stays, and / or reduce healthcare costs. In some examples, the collar may obtain feedback via wireless communication with other implantable or wearable devices, such as an implantable cardiac monitor or other cardiac monitoring device or a smartwatch.

[0007] In one example, the present disclosure is directed to a system comprising: a collar; a first stimulation electrode array positioned on the collar and configured to deliver stimulation therapy to a patient; a second stimulation electrode array positioned on the collar and configured to deliver stimulation therapy to the patient; a sensor array positioned on the collar and configured to detect one or more features indicative of laryngeal muscle activity of the patient; and a controller configured to control the stimulation therapy to be delivered via the first stimulation electrode array and the second stimulation electrode array.

[0008] As another example, the present disclosure relates to a method, the method comprising: applying an initial stimulation therapy to a patient via one or more of a first stimulation electrode array and a second stimulation electrode array, the first stimulation electrode array and the second stimulation electrode array being positioned on a collar; detecting one or more features indicating laryngeal muscle activity of the patient via a sensor array, the sensor array being positioned on the collar; determining, by the controller, a level of the laryngeal muscle activity based on the one or more features; and determining, by the controller, whether the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold.

[0009] The details of one or more examples are set forth in the accompanying drawings and the description below.Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.

[0010] The above summary is not intended to describe each illustrated example or every implementation of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A conceptual diagram illustrating an exemplary stimulation device in accordance with one or more techniques of the present disclosure.

[0012] FIG. 2A to FIG. 2C A conceptual diagram illustrating an exemplary stimulation device in accordance with one or more techniques of the present disclosure.

[0013] FIG. 3A to FIG. 3C Examples of stimulation of an exemplary stimulation electrode array in accordance with one or more techniques of the present disclosure are illustrated.

[0014] Figure 4 is a flow diagram illustrating an example technique that may be performed by one or more of a system or device in accordance with one or more techniques disclosed herein. DETAILED DESCRIPTION

[0015] Recent discoveries about VNS have revealed the involvement and control of the nervous system in the body's inflammatory response. The nervous system senses inflammation, pathogens, and tissue damage, and regulates the response. Animal and human studies have demonstrated that stimulation of the vagus nerve can attenuate the inflammatory response and associated cytokines. Recent studies have demonstrated that inflammatory cytokines can be up-regulated or down-regulated by varying the stimulation.

[0016] In addition, VNS can help stroke rehabilitation and treat ischemia-reperfusion injury. After cerebral infarction or stroke, reperfusion therapy (surgery or drugs) is given to restore blood flow. However, due to ischemia and blood flow recovery, local damage occurs, which is called ischemia-reperfusion injury. This will induce local brain accumulation of chemical mediators such as reactive oxygen species (ROS) production, inflammatory cytokines, bradykinin, etc. Therefore, the inflammatory state worsens. Inflammatory compounds will trigger sensory signal conduction, which may cause organ vagal activity reduction and sympathetic overactivation. VNS can treat reperfusion injury because the inflammatory state can be reduced by increasing parasympathetic activation.

[0017] Non-invasive VNS has been shown to downregulate inflammatory cytokines and more specifically reduce infarct growth and / or volume caused by stroke. However, current application methods have too much room for treatment error because some methods rely on manually applying stimulation electrodes (e.g., pads or patch electrodes) over the vagus nerve in the cervical region and / or do not provide feedback to confirm vagus nerve stimulation. Some current methods of applying non-invasive VNS may not properly guide VNS therapy, which may be based in part on lack of feedback. In addition, the treatment regimen may require periodic application of stimulation energy at multiple predetermined time intervals, which may require re-application of electrodes each time. The combination of these situations may result in inconsistent therapy application and suboptimal results. VNS devices that eliminate these potential inconsistencies will provide great benefits to patients suffering from stroke, traumatic brain injury (TBI) and other harmful conditions driven by inflammation.

[0018] Generally speaking, the present disclosure relates to devices, systems and techniques for performing transcutaneous VNS that can reduce or eliminate the inconsistent VNS therapy applied by current non-invasive VNS, which will provide great benefits to patients suffering from stroke, traumatic brain injury (TBI) and / or other harmful conditions driven by inflammation or other conditions that benefit from VNS.

[0019] Although the examples described herein relate to acute therapies for stroke and TBI, the stimulation device 10 can be used to deliver many other acute and chronic therapies known to respond to VNS. These include, but are not limited to: ischemic stroke / reperfusion injury; TBI; hemorrhagic stroke; epilepsy; obstructive sleep apnea (OSA); heart failure (HF); myocardial infarction (MI); heart rhythm problems; sepsis; postoperative ileus; acute kidney injury; stroke rehabilitation; autoimmunity; depression; anxiety; post-traumatic stress disorder (PTSD); Parkinson's disease PD; autonomic dysreflexia (AD); autism spectrum disorder (ASD); cognitive impairment (CD).

[0020] Figure 1 is a conceptual diagram illustrating an exemplary stimulation device 10. The stimulation device 10 can provide stimulation to a nerve, such as the vagus nerve. In some examples, the stimulation device 10 can provide stimulation non-invasively. In some examples, the stimulation device 10 can be configured to provide unilateral stimulation, bilateral stimulation, or alternating side stimulation to the left and right vagus nerves of the patient.

[0021] The stimulation device 10 may include a first stimulation electrode array 22 and a second stimulation electrode array 24. The first stimulation electrode array 22 may include one or more electrodes 22a, 22b, ... 22n. In some examples, the first stimulation electrode array 22 may have six electrodes, such as Figure 1As shown, but may also have more or fewer electrodes, such as but not limited to 2, 4, 8, 10, 12. In some examples, each electrode in array 22 may be independent of all other electrodes in the array and may be operated in a bipolar manner in pairs with any one or more electrodes in array 22. Second stimulation electrode array 24 may include one or more electrodes 24a, 24b...24n. In some examples, second stimulation electrode array 24 may have six electrodes, such as Figure 1 As shown, but there may be more or fewer electrodes, such as but not limited to 2, 4, 8, 10, 12. In some examples, each electrode in array 24 can be independent of all other electrodes in the array and can be operated in a bipolar manner with any one or more electrodes in array 22 in pairs. The first stimulation electrode array 22 can be configured to stimulate the vagus nerve, such as the left cervical vagus nerve or the right cervical vagus nerve. The second stimulation electrode array 24 can be configured to stimulate the vagus nerve on the opposite side of the neck to the first stimulation electrode array 22, such as the left cervical vagus nerve or the right cervical vagus nerve.

[0022] In some examples, the stimulation waveform can be monophasic or biphasic, with an amplitude of 0mA to 25mA, a pulse width of 20us to 450us, and a rate (such as frequency) of 5Hz to 500Hz. The amplitude, pulse width, and / or rate can also be quantities outside these ranges. In some examples, one or more electrodes in the first stimulation electrode array 22 and / or one or more electrodes in the second stimulation electrode array 24 can provide a low current alternating current (AC) or direct current (DC) waveform. The low current AC or DC waveform can allow amplitude and / or periodicity adjustment based on a feedback loop.

[0023] The stimulation device 10 may also include a sensor array 26. The sensor array 26 may include one or more sensors 26a, 26b, ... 26n. In some examples, the sensor array 26 may have six sensors, such as Figure 1 As shown, there may be more or fewer sensors, such as but not limited to 2, 4, 8, 10, 12.

[0024] The stimulation device 10 may include a collar 30, wherein the first stimulation electrode array 22, the second stimulation electrode array 24, and the sensor array 26 are positioned on the collar 30. In some examples, the first stimulation electrode array 22, the second stimulation electrode array 24, and the sensor array 26 are arranged on an inner surface 60 of the collar 30. The surface of the collar 30 that faces the patient while wrapping around the patient's neck is considered the inner surface 60 of the collar 30. The surface opposite the inner surface is considered the outer surface ( Figure 1). When one or more of the first stimulation electrode array 22, the second stimulation electrode array 24, or the sensor array 26 are used, the collar 30 may be configured to be wrapped around the patient's neck. The collar 30 may be formed of a variety of materials and have a variety of different sizes and / or thicknesses. The collar 30 may be flexible to fit necks of various sizes. The collar 30 may be attached or fixed to the patient's neck, such as by a collar or cuff wrapped around the neck, by an adhesive patch, or by a combination of these or by any other means. The collar 30 may also include an attachment device 40, such as a hook, a loop, and / or a fastener to attach the first end 12A of the collar 30 to the second end 12B of the collar 30 opposite to the first end 12A. In some examples, the attachment device 40 may help provide improved comfort around the neck area. The second end 12B may also include a mating attachment device (not shown) to match and attach to the attachment device 40, thereby fixing the collar 30 around the patient's neck. The sensor electrode array 26 may be positioned on the collar 30 so as to be positioned generally along the laryngeal region and beneath the patient's jaw when the collar 30 is wrapped around the patient to sense activation of muscles controlled by the laryngeal nerves.

[0025] In some examples, one or more of the electrodes in the first stimulation electrode array 22 may be raised or protruded from the inner surface 60 of the collar 30 so that one or more of the electrodes in the first stimulation electrode array 22 may be pressed into the neck to form a better contact, thereby increasing conductivity when the collar 30 is wrapped around the neck. In some examples, one or more of the electrodes in the second stimulation electrode array 24 may be raised or protruded from the inner surface 60 of the collar 30 so that one or more of the electrodes in the second stimulation electrode array 24 may be pressed into the neck to form a better contact, thereby increasing conductivity when the collar 30 is wrapped around the neck. In some examples, this configuration of one or more of the electrodes in the respective electrode arrays may reduce impedance and may position the electrodes physically closer to the vagus nerve. In some examples, the collar 30 may include an arch 32 configured to be positioned under the patient's jaw when wrapped around the patient. The arch 32 may be considered to be on the front side of the collar 30.

[0026] The first stimulation electrode array 22 may be positioned on the collar 30 so as to be positioned approximately over the left cervical vagus nerve or the right cervical vagus nerve when the collar 30 is fixed around the patient's neck to provide VNS to the corresponding vagus nerve over which the first stimulation electrode array 22 is positioned. The second stimulation electrode array 24 may be positioned on the collar 30 so as to be positioned approximately over the cervical vagus nerve when the collar 30 is fixed around the patient's neck to provide VNS to the corresponding nerve over which the second stimulation electrode array 24 is positioned, opposite the vagus nerve over which the first stimulation electrode array 22 is positioned approximately. The positioning of the first stimulation electrode array 22 and the second stimulation electrode array 24 on the collar 30 may provide a bilateral array of electrodes arranged over the left and right cervical vagus nerves to allow unilateral stimulation, bilateral stimulation, or alternating side stimulation of the patient's vagus nerves. This may enable a specific type of stimulation therapy to be provided based on the patient's therapy requirements. In addition, the bilateral stimulation electrode arrays 22, 24 provide multiple potential stimulation zones, thereby greatly increasing the chances of successful stimulation based on the initial fixation of the collar 30 to the patient and stimulation feedback.

[0027] In some examples, one or more sensors of sensor array 26 may be one or more EMG sensors in an electromyography (EMG) sensor, such as an electrode or an accelerometer. One or more sensors of sensor array 26 may additionally or alternatively include one or more sensors to identify changes in electroencephalogram (EEG), blood pressure, pulse, blood flow, respiration, temperature, activation of muscles not in the larynx, or any metric indicating VNS. Sensor array 26 may be configured to detect corresponding features indicating muscle activation of the patient (such as activation of the patient's laryngeal muscles). In some examples, when the sensors of sensor array 26 are electrodes, there may be a common electrode array that can be selectively used to deliver stimulation and sensing.

[0028] In examples where the sensors of sensor array 26 include one or more EMG sensors, the EMG sensors may be configured to detect laryngeal muscle activation of the patient when the collar 30 is secured to the patient. When the collar 30 is secured around the patient's neck, the sensor array 26 may be positioned on the collar 30 to be positioned generally over the patient's laryngeal region to detect laryngeal muscle activation. In some examples, the EMG sensors may protrude from the inner surface 60 of the collar 30 so that when the collar 30 is secured around the neck of the person receiving therapy, the EMG sensors create greater pressure / apposition against the patient's skin. Detecting an amount of laryngeal muscle activity above a laryngeal muscle activity threshold may indicate activation of the laryngeal nerves, which is indicative of VNS.

[0029] In examples where the sensors of sensor array 26 include one or more accelerometers, the accelerometers may be configured to monitor activation of laryngeal muscles and / or other muscles. For example, measurements made by one or more accelerometers may indicate activity of laryngeal muscles above a laryngeal muscle threshold, which indicates activation of muscles controlled by laryngeal nerves, which is indicative of VNS. In some examples, measurements made by one or more accelerometers may indicate muscle movement that does not correspond to laryngeal muscle movement, which may indicate incorrect positioning of the collar 30 on the patient.

[0030] In some examples, a decrease in pulses (e.g., pulse rate) during stimulation therapy can indicate VNS. In some examples, one or more sensors in sensor array 26 may be configured to sense the patient's pulse. In some examples, one or more of the electrodes in first stimulation electrode array 22 and / or second stimulation electrode array 24 may be configured to sense cardiac depolarizations indicative of the patient's pulse. In some examples, one or more external sensors configured to communicate with collar 30 may be configured to sense the patient's pulse. In some examples, one or more of the sensors in sensor array 26, electrodes in first stimulation electrode array 22 and / or second stimulation electrode array 24, and / or an external sensor configured to communicate with collar 30 (such as an electrocardiogram (ECG) lead of a device other than collar 30) may be configured to sense the patient's pulse.

[0031] In some examples, controller 70 may determine a pulse drop based on the patient's sensed pulse over a period of time during stimulation therapy. In some examples, controller 70 may determine whether the pulse drop during stimulation therapy meets a pulse drop VNS threshold indicating VNS.

[0032] In some examples, a drop in blood pressure during stimulation therapy may indicate VNS. In some examples, one or more sensors in sensor array 26 may be configured to sense the patient's blood pressure. In some examples, one or more of the electrodes in first stimulation electrode array 22 and / or second stimulation electrode array 24 may be configured to sense the patient's blood pressure. In some examples, one or more external sensors configured to communicate with collar 30 may be configured to sense the patient's blood pressure. In some examples, one or more of the sensors in sensor array 26, electrodes in first stimulation electrode array 22 and / or second stimulation electrode array 24, and / or an external sensor configured to communicate with collar 30 (such as an external cuff of a device other than collar 30) may be configured to sense the patient's blood pressure.

[0033] In some examples, the controller 70 may determine a drop in blood pressure based on the patient's sensed blood pressure over a period of time during stimulation therapy. In some examples, the controller 70 may determine whether the drop in blood pressure during stimulation therapy meets a blood pressure drop VNS threshold indicating VNS.

[0034] In some examples, the controller 70 may determine whether one or more vagus nerves are being stimulated based on one or more of laryngeal muscle activity, a drop in the patient's pulse during stimulation therapy, and / or a drop in blood pressure during stimulation therapy. In some examples, the controller 70 may generate an output to indicate whether one or more vagus nerves are being stimulated based on one or more of laryngeal muscle activity, a drop in the patient's pulse during stimulation therapy, and / or a drop in blood pressure during stimulation therapy.

[0035] The lining of the inner surface 60 of the loop 30 can be coated with a conductive gel to promote better electrical contact between the loop and the skin. Additionally or alternatively, one or more of the electrodes in the first stimulation electrode array 22 and / or the second stimulation electrode array 24 and the sensors in the sensor array 26 can be coated with a conductive gel to promote better electrical contact between the loop and the skin. In some examples, the loop 30 can be manufactured with such a gel pre-applied to the loop, electrodes, and / or sensors. In some examples, the gel can be protected by a structure or film that can be easily removed by a user (such as a caregiver), or can be automatically removed when the stimulation device 10 is removed from its packaging.

[0036] In some examples, the collar 30 may include a controller 70 that is electrically and / or communicatively coupled to one or more of the first stimulation electrode array 22, the second stimulation electrode array 24, or the sensor array 26. Figure 1 The collar 30 is shown including a controller 70 , but in some examples the controller 70 may be external to the collar 30 and electrically and / or communicatively coupled to one or more of the first stimulation electrode array 22 , the second stimulation electrode array 24 , or the sensor array 26 .

[0037] The controller 70 may provide and / or adjust stimulation of one or more of the first stimulation electrode array 22 or the second stimulation electrode array 24. In some examples, the controller 70 may adjust the amplitude, pulse width, stimulation period, electrode current geometry, and / or waveform of the stimulation. For example, the amplitude, pulse width, and / or waveform of the stimulation signal provided to one or more of the first stimulation electrode array 22 or the second stimulation electrode array 24 may be varied or adjusted based on one or more of the patient's body type or the signal requirements for activating one or more vagus nerves. The controller 70 may adjust the amplitude, pulse width, stimulation period, electrode current geometry, and / or waveform of the stimulation signal provided to one or more of the first stimulation electrode array 22 or the second stimulation electrode array 24 based on the change in impedance. In some examples, the controller 70 may adjust the dipole pattern within the first stimulation electrode array 22 and / or the second stimulation electrode array 24. For example, the controller 70 may pair different combinations of electrodes in the corresponding electrode arrays to produce different dipoles, may produce multiple dipoles within the electrode array, and / or use one or more electrodes of the corresponding electrode array as a monopole. In some examples, the controller 70 can provide a stimulation waveform that includes short bursts of high-frequency stimulation, such as, but not limited to, a 5 kilohertz (kHz) sine wave repetition block with a 500 μsec duration repeated at a frequency of 25 Hz. In some examples, the stimulation waveform can be monophasic or biphasic, with an amplitude of 0 mA to 25 mA, a pulse width of 20 us to 450 us, and / or a frequency of 5 Hz to 500 Hz. The amplitude, pulse width, and / or frequency can also be quantities outside of these ranges. In some examples, the controller 70 can be operable by a user such as a clinician, an EMT, or a patient.

[0038] In some examples, the controller 70 may be a computing device including one or more of a processing circuit, a memory, a sensing circuit, a stimulation circuit, or a communication circuit. For example, an external computing device 90 may communicate with the controller 70 via a communication circuit. In some examples, the computing device 90 may include a smart phone, a desktop computer, a laptop, or a tablet computer or a workstation. The computing device 90 may include a mobile application that communicates with the controller 70. The mobile application may include preset information about the type, intensity, past treatment, patient history, etc. of the therapy. In one example, specific features on the application may also be unlocked by the manufacturer, supplier, or healthcare provider based on pre-approved therapy for the patient. In some examples, the controller 70 may receive information and / or instructions about the type, intensity, past treatment, patient history, etc. of the therapy from the computing device 90. In some examples, some or all of the processing (such as comparison, determination, adjustment, etc.) discussed as being performed by the controller 70 may be performed by the computing device 90 and transmitted to the controller 70 for data transmission.

[0039] The stimulation device 10 may include a collar 30, a first stimulation electrode array 22, a second stimulation electrode array 24, and a sensor array 26. The stimulation device 10 may also include a controller 70 or be communicatively coupled to the controller 70. In some examples, when the collar 30 is positioned on the patient to provide stimulation therapy to one or more vagus nerves of the patient, the controller 70 may deliver the stimulation therapy via the first stimulation electrode array 22 and / or the second stimulation electrode array 24 in an initial amount. In some examples, the initial amount of the stimulation therapy may be predetermined. In some examples, the initial amount of the stimulation therapy may be based on the patient, such as one or more of the body type, the type of health event that occurs, the age, the weight, or other physiological data of the patient. In some examples, the initial amount of the stimulation therapy may be set by a user such as a clinician or an EMT. Some examples of the characteristics of the stimulation therapy provided via the first stimulation electrode array 22 and / or the second stimulation electrode array 24 may include the amplitude and / or waveform of the stimulation therapy. In some examples, additional or alternative features of the stimulation therapy provided via first stimulation electrode array 22 and / or second stimulation electrode array 24 may include whether the stimulation is unilateral, bilateral, or alternating side stimulation. There may be additional features of the stimulation therapy to be provided via first stimulation electrode array 22 and / or second stimulation electrode array 24, such as pulse rate, duration, and / or other features for providing the stimulation therapy.

[0040] Characteristics of the stimulation therapy to be provided may be determined for an initial amount of stimulation therapy to be provided via the first stimulation electrode array 22 and / or the second stimulation electrode array 24. While providing the initial amount of stimulation therapy, the sensor array 26 may detect activation of muscles controlled by the laryngeal nerves. The controller 70 may compare the amount detected by the sensor array 26 with an activation threshold. In response to the amount of laryngeal muscle activation detected being greater than or equal to the activation threshold, the controller 70 determines that one or more of the vagus nerves are stimulated. In response to the amount of laryngeal muscle activation detected being less than the activation threshold, the controller 70 determines that the vagus nerve is not stimulated or is insufficiently stimulated.

[0041] In response to the controller 70 determining that the vagus nerve is not stimulated or not sufficiently stimulated, the controller 70 may generate an output to indicate that the vagus nerve is not stimulated or not sufficiently stimulated. In some examples, the output may be output via an output generator 95 coupled to the collar 30. In some examples, the output generator 95 may be a light, and the output may include an error signal via a flashing light. In some examples, the output generator 95 may be a speaker, and the output may be an audio signal output via the speaker. In some examples, the output generator 95 may be a combination of a speaker and a light, and the output may be a combination of a light and an audio signal. The output generator 95 may be located at any position on the collar 30. In some examples, the output generator 95 may be outside the collar 30. For example, the generated output may indicate to a user such as an EMT that the collar 30 needs to be repositioned on the patient to provide improved vagus nerve stimulation via the first stimulation electrode array 22 and / or the second stimulation electrode array 24 and / or improve signal acquisition via the sensor array 26. In some examples, the generated output may also indicate a need to adjust a characteristic of the stimulation therapy via first stimulation electrode array 22 and / or second stimulation electrode array 24 .

[0042] In some examples, the controller 70 may send the generated output to the computing device 90. The computing device 90 may then output an audio or light signal to indicate that the vagus nerve is not stimulated or is not sufficiently stimulated. In some examples, the controller 70 may send an indication to the computing device 90 of whether the collar 30 needs to be adjusted and / or whether the characteristics of the stimulation therapy via the first stimulation electrode array 22 and / or the second stimulation electrode array 24 need to be adjusted. In some examples, the indication may be displayed on the user interface of the computing device 90 to notify a user such as an EMT of what adjustments are made to the characteristics of the stimulation therapy to provide efficient and effective stimulation therapy to one or more vagus nerves of the patient. In some examples, the controller 70 may output an indication suggesting one or more adjustments to the stimulation therapy based at least on the detection performed by the sensor array 26. Some examples of adjustment may include adjusting one or more of the amplitude, waveform, pulse rate, duration, and / or other characteristics of the stimulation therapy provided via the first stimulation electrode array 22 and / or the second stimulation electrode array 24. In some examples, the controller 70 may output an indication suggesting that the stimulation therapy is unilateral stimulation, bilateral stimulation, or alternating side stimulation.

[0043] In some examples, in response to the controller 70 determining that the vagus nerve is not stimulated or is not sufficiently stimulated, the controller 70 may adjust one or more features of the stimulation therapy provided via the first stimulation electrode array 22 and / or the second stimulation electrode array 24. For example, the controller 70 may activate different electrodes in the first stimulation electrode array 22 and / or the second stimulation electrode array 24. In some examples, the controller 70 may adjust the amplitude, waveform, pulse rate, duration, and / or other features of the stimulation therapy. In some examples, the controller 70 may adjust the stimulation therapy to unilateral stimulation, bilateral stimulation, or alternating side stimulation. For example, if the initial stimulation is unilateral stimulation via the first stimulation electrode array 22, the controller may adjust the stimulation therapy to bilateral stimulation, alternating side stimulation, or unilateral stimulation via the second stimulation electrode array 24. In some examples, a user such as an EMT may adjust the position of the collar 30 on the patient to provide better signal acquisition and / or improve comfort for the patient. The controller 70 may also adjust any combination of features of the stimulation therapy. Closed-loop feedback VNS therapy may provide patients with faster, simpler, and more effective VNS therapy, which may be particularly important during health events such as stroke, TBI, or other detrimental conditions driven by inflammation.

[0044] After adjusting the stimulation therapy, the controller 70 may determine whether one or more vagus nerves are stimulated by the adjusted stimulation therapy based on one or more features detected by the sensor array 26. For example, the controller 70 may determine whether the amount of laryngeal muscle activity is above a laryngeal muscle activity threshold based on one or more features detected by the sensor array 26. In some examples, if the controller 70 determines that the laryngeal muscle activity is below the laryngeal muscle activity threshold after one or more adjustments to the features of the stimulation therapy, the controller may generate an output to indicate that the vagus nerve is not stimulated or is not sufficiently stimulated according to the examples discussed above. In some examples, the controller 70 may attempt multiple adjustments to the features of the stimulation therapy before generating an output to indicate that the vagus nerve is not stimulated or is not sufficiently stimulated.

[0045] In some examples, the collar 30 may include a power source 80, such as a battery. In some examples, the collar 30 may include a power source 80 and / or a controller 70 that is electrically and / or communicatively coupled to one or more of the first stimulation electrode array 22, the second stimulation electrode array 24, or the sensor array 26. In some examples, the power source 80 may be external to the collar 30, and the collar 30 may be coupled to the external power source via a cable. In some examples, the controller 70 and the power source 80 may both be external to the collar 30 and electrically coupled to the electrodes and sensors in the collar 30 using cables.

[0046] FIG. 2A to FIG. 2CA conceptual diagram of an exemplary stimulation device 10 to be positioned on a patient 14 is illustrated. FIG. 2A to FIG. 2C As shown, the collar 30 may include an arch 32 that is configured to be positioned beneath the chin of the patient 14 when the collar 30 is wrapped around the patient. Figure 2C An example is shown in which the sensor electrode array 26 may be positioned on the collar 30 so as to be positioned generally along the laryngeal region and beneath the patient's jaw when the collar 30 is wrapped around the patient 14 to sense activation of muscles controlled by the laryngeal nerves. Figure 2C An exemplary location of the sensor electrode array 26 is shown, but the sensor electrode array 26 is positioned on the inner surface 60 of the collar 30 . Figure 2C 1. The second stimulation electrode array 24 is shown as being positionable on the collar 30 so as to be positioned generally over the vagus nerve in the neck when the collar 30 is secured around the neck of the patient 14 to provide VNS to the corresponding nerve over which the second stimulation electrode array 24 is positioned. The first stimulation electrode array 22 is positionable on the collar 30 so as to be positioned generally over the vagus nerve on the corresponding mirror-opposite side of the neck of the patient 14, with the second stimulation electrode array 24 positioned relative to the patient 14. Although Figure 2C An exemplary location of the second stimulation electrode array 24 is shown, but the second stimulation electrode array 24 is positioned on the inner surface 60 of the collar 30. The first stimulation electrode array 22 is also positioned on the inner surface 60 of the collar 30.

[0047] FIG. 3A to FIG. 3C An example of how the electrodes of the first stimulation electrode array 22 and / or the second stimulation electrode array 24 may be arranged and operated to deliver stimulation to a target nerve 250 (particularly the vagus nerve) is illustrated. Although the following discussion will relate to the first stimulation electrode array 22 and the electrodes 22a, 22b ... 22n in the first stimulation electrode array 22, the description may also apply to the second stimulation electrode array 24 and the electrodes 24a, 24b ... 24n in the second stimulation electrode array 24. In some examples, such as Figure 3A As shown in the example of , electrodes 22a and 22b can be positioned on opposite sides of a target nerve 250 and can each generate an electric field at the same frequency (eg, 20 Hz) to deliver stimulation signals at an effective stimulation frequency.

[0048] In some examples, such as Figure 3A As shown in the example of , electrodes 22a and 22b can be positioned on opposite sides of a target nerve 250 and can each generate an electric field at the same frequency (eg, 20 Hz) to deliver stimulation signals.

[0049] In some examples, such as Figure 3BAs shown in the example of FIG. 2 , electrodes 22a and 22b can be positioned as nested electrode pairs on opposite sides of the target nerve 250, and each electrode pair 22a and 22b can create two separate electric fields at a high frequency, such as a carrier frequency. For example, electrode pair 22a can generate two fields with frequencies of 3.000kHz and 3.020kHz, and electrode pair 22b can generate two fields with frequencies of 3.000kHz and 3.020kHz. In the case where the two fields overlap, the interfering field will have an effective stimulation frequency of 20Hz.

[0050] In some examples, such as Figure 3C As shown in the example in , electrodes 22a and 22b can be positioned as staggered electrode pairs on opposite sides of the target nerve 250, and each electrode pair 22a and 22b can create two separate electric fields at a high frequency such as a carrier frequency. For example, electrode pair 22a can generate two fields with frequencies of 3.000kHz and 3.020kHz, and electrode pair 22b can generate two fields with frequencies of 3.000kHz and 3.020kHz. In the case where the two fields overlap, the interfering field will have an effective stimulation frequency of 20Hz.

[0051] Although FIG. 3A to FIG. 3C Two electrodes are shown as an example, but Figure 1 The electrode array shown and described above can be used to stimulate the target nerve. In addition, different configurations can be used to provide each field, and in doing so, the peak interference can be manipulated, and the best combination can be evaluated by monitoring muscle contractions from the replicated vagus nerve via the sensor array 26.

[0052] Figure 4is a flow chart illustrating an exemplary technique according to the present disclosure. The controller 70 may cause an initial stimulation therapy to be applied via one or more of the first stimulation electrode array 22 or the second stimulation electrode array 24 (402). The controller 70 may determine whether one or more vagus nerves are stimulated based on one or more features detected by the sensor array 26 (404). For example, the controller 70 may determine whether laryngeal muscle activation is greater than or equal to a laryngeal muscle activation threshold based on one or more features detected by the sensor array 26 to determine whether the vagus nerve is stimulated. In response to determining that one or more vagus nerves are stimulated, the controller 70 may continue to cause the stimulation therapy to be delivered with the same or similar features as the stimulation therapy being delivered (406). In response to determining that one or more vagus nerves are not stimulated or are not sufficiently stimulated, the controller 70 may adjust one or more features of the stimulation therapy to be applied via one or more of the first stimulation electrode array 22 or the second stimulation electrode array 24 (408). In response to determining that one or more vagus nerves are not stimulated or insufficiently stimulated, the controller 70 may generate an output to indicate that the vagus nerve is not stimulated or insufficiently stimulated (410). In some examples, the controller 70 may not generate an output until the adjustment amount is greater than or equal to the adjustment threshold. For example, the adjustment threshold may be any amount between 1 and 10 adjustments. In some examples, the adjustment threshold may be greater than 10. In some examples, the controller 70 may not generate an output until the duration of applying and / or adjusting the stimulation therapy is greater than or equal to the duration threshold. For example, the duration threshold may be any value between 1 second and 10 minutes. In some examples, the duration threshold may be less than 1 second or greater than 10 minutes.

[0053] It should be noted that the technology described herein may not be limited to the treatment or monitoring of human patients. In an alternative example, the technology disclosed herein may be applied to non-human patients, such as primates, canines, horses, pigs, sheep, and felines. These other animals may undergo clinical or research therapies that may benefit from the disclosed subject matter.

[0054] Various examples are discussed with respect to one or more stimulation devices. It is recognized that stimulation devices may include features and functionality in addition to electrical stimulation. Many of these additional features are explicitly discussed herein. Several exemplary features include, but are not limited to, different types of sensing capabilities and different types of wireless communication capabilities. For ease of discussion, the present disclosure does not explicitly recite every conceivable combination of additional features, such as by repeating each feature each time a different example and use of a stimulation device is discussed.

[0055] The technology of the present disclosure can be implemented in a wide range of computing devices, medical devices, or any combination thereof. Any described unit, circuit, or component can be implemented together or separately as a discrete but interoperable logic device. Describing different features as circuits or units is intended to highlight different functional aspects, and does not necessarily imply that such circuits or units must be implemented by separate hardware or software components. On the contrary, the functions associated with one or more circuits or units can be performed by separate hardware or software components, or integrated in common or separate hardware or software components.

[0056] The present disclosure contemplates a computer-readable storage medium including instructions that cause a processor to perform any of the functions and techniques described herein. The computer-readable storage medium may take the example form of any volatile, non-volatile, magnetic, optical, or electrical medium such as RAM, ROM, NVRAM, EEPROM, or tangible flash memory. The computer-readable storage medium may be referred to as non-transient. The server, client computing device, or any other computing device may also include a more portable type of removable memory to enable easy data transfer or offline data analysis.

[0057] The techniques described in this disclosure, including those attributable to various circuits and various component parts, may be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, various aspects of these techniques may be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated discrete logic circuits or other processing circuits, as well as any combination of such components, remote servers, remote client devices, or other devices. The term "processing circuit" or "processing circuitry" may generally refer to any of the foregoing logic circuits, alone or in combination with other logic circuits, or any other equivalent circuits.

[0058] Such hardware, software, firmware may be implemented in the same device or in separate devices to support the various operations and functions described in this disclosure. In addition, any described unit, circuit or component may be implemented together or separately as a discrete but interoperable logic device. Describing different features as circuits or units is intended to highlight different functional aspects and does not necessarily imply that such circuits or units must be implemented by separate hardware or software components. On the contrary, the functions associated with one or more circuits or units may be performed by separate hardware or software components, or integrated in common or separate hardware or software components. For example, any circuit described herein may include a circuit configured to perform features attributed to that particular circuit, such as a fixed-function processing circuit, a programmable processing circuit, or a combination thereof.

[0059] In some examples, computer-readable storage media include non-transitory media. The term "non-transitory" may indicate that the storage media is not embodied in a carrier wave or propagating signal. In some examples, non-transitory storage media may store data that may change over time (e.g., in RAM or cache).

[0060] The present disclosure includes the following non-limiting examples.

[0061] Embodiment 1: A system comprising: a collar; a first stimulation electrode array, the first stimulation electrode array being positioned on the collar and configured to deliver stimulation therapy to a patient; a second stimulation electrode array, the second stimulation electrode array being positioned on the collar and configured to deliver stimulation therapy to the patient; a sensor array, the sensor array being positioned on the collar and configured to detect one or more features indicative of laryngeal muscle activity of the patient; and a controller, the controller being configured to control the stimulation therapy to be delivered via the first stimulation electrode array and the second stimulation electrode array.

[0062] Embodiment 2: The system of Embodiment 1, wherein the sensor array is positioned on the loop between the first stimulation electrode array and the second stimulation electrode array when the loop is stretched outward.

[0063] Embodiment 3: The system of any one of embodiments 1 to 2, wherein the collar includes a chinarc, and when the collar is positioned around the patient's neck, the sensor array is positioned below the chinarc.

[0064] Example 4: A system according to any one of Examples 1 to 3, wherein when the loop is positioned around the patient's neck, the first stimulation electrode array is positioned to deliver stimulation therapy to the patient's left vagus nerve, and the second stimulation electrode array is positioned to deliver stimulation therapy to the patient's right vagus nerve.

[0065] Embodiment 5: The system of any one of embodiments 1 to 4, wherein the controller is further configured to control the stimulation therapy based on at least detected features indicative of laryngeal muscle activity of the patient.

[0066] Embodiment 6: A system according to any one of embodiments 1 to 5, wherein the controller is further configured to: determine a level of laryngeal muscle activity based on characteristics detected by the sensor array; determine that the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold; and in response to determining that the level of laryngeal muscle activity is less than the laryngeal muscle activity threshold, adjust one or more characteristics of the stimulation therapy to be delivered via one or more of the first stimulation electrode array or the second stimulation electrode array.

[0067] Embodiment 7: A system according to any one of embodiments 1 to 5, wherein the controller is further configured to: determine a level of laryngeal muscle activity based on characteristics detected by the sensor array; determine that the level of laryngeal muscle activity is greater than or equal to a laryngeal muscle activity threshold; and in response to determining that the level of laryngeal muscle activity is greater than or equal to the laryngeal muscle activity threshold, maintain one or more characteristics of the stimulation therapy to be delivered via one or more of the first stimulation electrode array or the second stimulation electrode array.

[0068] Embodiment 8: A system according to any one of embodiments 1 to 5, wherein the controller is further configured to: determine a level of laryngeal muscle activity based on characteristics detected by the sensor array; determine that the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold; and in response to determining that the level of laryngeal muscle activity is less than the laryngeal muscle activity threshold, generate an output to indicate that one or more vagus nerves are not stimulated.

[0069] Embodiment 9: The system of Embodiment 8, wherein the generated output comprises a suggested adjustment to the position of the collar on the patient or an adjustment to one or more features of the stimulation therapy.

[0070] Embodiment 10: The system of any one of Embodiments 8 to 9, wherein the generated output comprises one or more of an audio alarm signal or a visual alarm signal.

[0071] Embodiment 11: The system of any one of Embodiments 8 to 10, further comprising an output generator to output one or more of an audio alarm signal or a visual alarm signal.

[0072] Embodiment 12: The system of any one of Embodiments 1 to 11, wherein the laryngeal muscle activity greater than or equal to the laryngeal muscle activity threshold is indicative of vagus nerve stimulation.

[0073] Embodiment 13: The system according to any one of embodiments 1 to 12, wherein the system is a stimulation device.

[0074] Embodiment 14: The system of any one of Embodiments 1 to 13, wherein one or more sensors in the sensor array are electromyographic sensors.

[0075] Embodiment 15: The system of any one of Embodiments 1 to 14, wherein one or more sensors in the sensor array are accelerometers.

[0076] Embodiment 16: A method, comprising: applying an initial stimulation therapy to a patient via one or more of a first stimulation electrode array and a second stimulation electrode array by a controller, wherein the first stimulation electrode array and the second stimulation electrode array are positioned on a collar; detecting one or more features indicating laryngeal muscle activity of the patient by a sensor array, wherein the sensor array is positioned on the collar; determining a level of laryngeal muscle activity by the controller based on the one or more features; and determining whether the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold by the controller.

[0077] Example 17: The method according to Example 16 also includes: in response to determining that the laryngeal muscle activity is less than the laryngeal muscle activity threshold, adjusting one or more characteristics of the stimulation therapy to be applied via one or more of the first stimulation electrode array and the second stimulation electrode array by the controller.

[0078] Embodiment 18: The method according to any one of embodiments 16 to 17 further includes: in response to determining that the laryngeal muscle activity is less than the laryngeal muscle activity threshold, outputting, via the controller, an indication that one or more vagus nerves are not stimulated.

[0079] Example 19: The method according to any one of Examples 16 to 18, further comprising: in response to determining that the laryngeal muscle activity is greater than or equal to the laryngeal muscle activity threshold, maintaining one or more characteristics of the stimulation therapy to be applied via one or more of the first stimulation electrode array and the second stimulation electrode array.

[0080] Example 20: The method according to any one of Examples 17 to 19, further comprising: applying the adjusted stimulation therapy to the patient via one or more of the first stimulation electrode array and the second stimulation electrode array by the controller; detecting one or more features indicating laryngeal muscle activity of the patient by the sensor array while the adjusted stimulation therapy is being applied; determining the level of laryngeal muscle activity by the controller based on the one or more features detected while the adjusted stimulation therapy is being applied; and determining by the controller whether the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold while the adjusted stimulation therapy is being applied.

[0081] Example 21: The method according to Example 20 also includes: in response to determining that the laryngeal muscle activity is less than the laryngeal muscle activity threshold when the adjusted stimulation therapy is being applied, adjusting one or more characteristics of the adjusted stimulation therapy to be applied via one or more of the first stimulation electrode array and the second stimulation electrode array by the controller.

[0082] Example 22: The method according to any one of Examples 20 to 21 further includes: in response to determining that the laryngeal muscle activity is less than the laryngeal muscle activity threshold when the adjusted stimulation therapy is being applied, outputting an indication that one or more vagus nerves are not stimulated via the controller.

[0083] Embodiment 24: A computer-readable medium storing instructions, which, when executed by one or more processors, cause the one or more processors to perform the method according to any one of Embodiments 1 to 23.

[0084] Various embodiments have been described herein. Any combination of the described operations or functions is contemplated. These and other examples are within the scope of the appended claims. Based on the above discussion and illustrations, it has been recognized that various modifications and changes may be made to the disclosed embodiments in a manner that does not require strict adherence to the embodiments and applications illustrated and described herein. Such modifications do not depart from the true spirit and scope of the various aspects of the present disclosure, including the aspects set forth in the claims.

Claims

1. A system, comprising: Ring; a first stimulation electrode array positioned on the collar and configured to deliver stimulation therapy to the patient; a second stimulation electrode array positioned on the collar and configured to deliver stimulation therapy to the patient; a sensor array positioned on the collar and configured to detect one or more features indicative of laryngeal muscle activity of the patient; and A controller is configured to control stimulation therapy to be delivered via the first stimulation electrode array and the second stimulation electrode array.

2. The system of claim 1, wherein the sensor array is positioned on the loop between the first stimulation electrode array and the second stimulation electrode array when the loop is stretched outward.

3. The system of any one of claims 1 to 2, wherein the collar includes a mandibular arch, and the sensor array is positioned below the mandibular arch when the collar is positioned around the patient's neck.

4. The system of any one of claims 1 to 3, wherein when the collar is positioned around the patient's neck, the first stimulation electrode array is positioned to deliver stimulation therapy to the patient's left vagus nerve, and the second stimulation electrode array is positioned to deliver stimulation therapy to the patient's right vagus nerve.

5. The system of any one of claims 1 to 4, wherein the controller is further configured to control the stimulation therapy based on at least detected features indicative of laryngeal muscle activity of the patient.

6. The system according to any one of claims 1 to 5, wherein the controller is further configured to: determining a level of laryngeal muscle activity based on the features detected by the sensor array; determining that the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold; as well as In response to determining that the level of laryngeal muscle activity is less than the laryngeal muscle activity threshold, one or more characteristics of the stimulation therapy to be delivered via one or more of the first stimulation electrode array or the second stimulation electrode array are adjusted.

7. The system according to any one of claims 1 to 5, wherein the controller is further configured to: determining a level of laryngeal muscle activity based on the features detected by the sensor array; determining that the level of laryngeal muscle activity is greater than or equal to a laryngeal muscle activity threshold; as well as In response to determining that the level of laryngeal muscle activity is greater than or equal to the laryngeal muscle activity threshold, maintaining one or more characteristics of the stimulation therapy to be delivered via one or more of the first stimulation electrode array or the second stimulation electrode array.

8. The system according to any one of claims 1 to 5, wherein the controller is further configured to: determining a level of laryngeal muscle activity based on the features detected by the sensor array; determining that the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold; as well as In response to determining that the level of laryngeal muscle activity is less than the laryngeal muscle activity threshold, an output is generated to indicate that one or more vagus nerves are not stimulated.

9. The system of claim 8, wherein the generated output comprises a suggested adjustment to the position of the collar on the patient or an adjustment to one or more characteristics of the stimulation therapy.

10. The system of any one of claims 8 to 9, wherein the generated output comprises one or more of an audio warning signal or a visual warning signal.

11. The system of any one of claims 1 to 10, wherein the laryngeal muscle activity greater than or equal to a laryngeal muscle activity threshold is indicative of vagus nerve stimulation.

12. The system according to any one of claims 1 to 11, wherein the system is a stimulation device.

13. The system of any one of claims 1 to 12, wherein one or more sensors in the sensor array are electromyographic sensors.

14. The system of any one of claims 1 to 13, wherein one or more sensors in the sensor array are accelerometers.

15. A computer readable medium storing instructions which, when executed by one or more processors, cause the one or more processors to: applying an initial stimulation therapy to the patient via one or more of a first stimulation electrode array and a second stimulation electrode array, the first stimulation electrode array and the second stimulation electrode array being positioned on the collar; detecting one or more features indicative of laryngeal muscle activity of the patient via a sensor array, the sensor array being positioned on the collar; determining a level of laryngeal muscle activity based on the one or more characteristics; as well as It is determined that the level of laryngeal muscle activity is less than a laryngeal muscle activity threshold.

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