Systems, devices and methods for acute autonomic stimulation

#This application relates generally to medical devices and, more particularly, to systems, devices and methods for providing acute autonomic stimulation.

#A reduced autonomic balance during heart failure has been shown to be associated with left ventricular dysfunction and increased mortality. This reduced autonomic balance increases sympathetic and decreases parasympathetic cardiac tone. Direct stimulation of the vagal parasympathetic fibers has been shown to reduce heart rate via activation of the parasympathetic nervous system and indirect inhibition of the sympathetic nervous system. Some data indicate that increasing parasympathetic tone and reducing sympathetic tone may protect the myocardium from further remodeling and predisposition to fatal arrhythmias following myocardial infarction; and some data indicates that chronic stimulation of the vagus nerve may protect the myocardium following cardiac ischemic insult. Vagus nerve stimulation increases parasympathetic tone and decreases sympathetic tone. However, implantation of electrodes is an invasive procedure, and it can be difficult to immediately implant electrodes after a myocardial infarction.

#Various system embodiments comprise a medical device, comprising a flexible tether, a neural stimulation circuit, and a controller. The flexible tether is adapted to be fed into a patient's throat. The flexible tether includes a plurality of electrodes. The neural stimulation circuit is adapted to deliver neural stimulation. The controller is adapted to control the neural stimulation circuit to provide a neural stimulation therapy using at least one electrode from the plurality of electrodes, and to implement a neural stimulation test routine. The neural stimulation test routine is adapted to assess neural stimulation efficacy for electrode subsets of the plurality of electrodes to identify a desired electrode subset for use in delivering the neural stimulation therapy to elicit a desired response.

#FIG. 1 illustrates the physiology of the upper respiratory/digestive systems.

#FIG. 2 illustrates the vagus nerve superimposed on the upper respiratory/digestive systems illustrated in FIG. 1.

#FIG. 3 illustrates an embodiment where a flexible tether is fed through a mouth into a patient's throat to position electrode(s) in the pharynx.

#The following detailed description of the present subject matter refers to the accompanying drawings which show, by way of illustration, specific aspects and embodiments in which the present subject matter may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present subject matter. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present subject matter. References to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined only by the appended claims, along with the full scope of legal equivalents to which such claims are entitled.

#The present subject matter provides a portable, external device with a flexible tether adapted to pass electrode(s) through a patient's nose or mouth into, and in some embodiments through, the patient's throat. Various embodiments pass the stimulation electrode(s) through the patient's throat into the patient's trachea, using orotracheal intubation (passing the endotracheal tube through the mouth, through the larynx, and into the trachea) or using nasotracheal intubation (passing the tube through the nose, through the larynx, and into the trachea). Various embodiments pass the stimulation electrode(s) through the patient's throat into the patient's larynx. Various embodiments pass the stimulation electrode(s) through the patient's throat into the patient's esophagus. The electrode(s) are positioned to provide stimulation of the vagus nerve. Vagus nerve stimulation increases parasympathetic tone and decreases sympathetic tone.

#In various embodiments, the flexible tether includes a flexible intubation tube to be placed in the patient's throat. The flexible intubation tube can be similar to tubes used in a transesophageal echocardiogram (TEE) system. The tube is designed to be inserted into the patient's throat, either passively (if the patient is conscious) or actively. For example, if the patient is conscious, the patient can swallow the tube to advance the tube into the throat, and to further advance the tube into the esophagus. If the patient is not conscious, the tube can be inserted through the nose or mouth into the throat. The end of the tube can be positioned in the pharynx, the larynx, the trachea or the esophagus. Sedatives can be administered to reduce discomfort and increase relaxation. A mouthpiece can be used to guide the tube into the throat. The tube itself can be lubricated to assist with the insertion procedure.