Abstract: Method and apparatus for providing on-demand stimulation of the gastrointestinal tract. The apparatus features an implantable pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular layer of the stomach. The pulse generator preferably features sensor for sensing abnormalities in gastric electrical activity. The pulse generator further features recognizing the type of gastric abnormality sensed. That is detecting whether gastric arrhythmia, bradygastria, dysrhythmia, tachygastria or retrograde propagation or uncoupling are present. If any of these gastric rhythm abnormalities are detected, then the pulse generator features emitting stimulation pulse trains to the gastric system to treat the detected gastric rhythm abnormalities. The stimulation pulse trains may take many forms and may be emitted for various periods of time.

Abstract: A system and method are provided for anchoring a cranial lead or catheter member within a cranial burr hole in a patient, utilizing a feed-through subassembly which permits a lead to be eccentrically positioned with respect to the center of the burr hole, enabling fixation of the lead to the skull while the lead is maintained stereotactically rigid. The feed-through, or anchoring assembly comprises a burr hole element which is positioned within the burr hole, having a radial slit which extends axially through the piece and has a groove for receiving and containing an O-ring, which O-ring is adjustably positioned radially along the slit in accordance with the target position. The O-ring is made of a compressive material, and has a center orifice which closely receives the lead.

Abstract: A system for providing electrical stimulation to the trigeminal nerve through a lead. The lead features a lead body, a coupling for connecting a lead into a medical stimulator and a distal electrode assembly. The electrode assembly features a pair of oppositely disposed curved semi-circular cuffs disposed to conform a lumen therethrough. The ends of each cuff are mounted into a resilient hinge disposed upon the distal end of the lead body. The hinge biases the cuffs towards one another in such a manner that the lumen is maintained patent such that the nerve will remain therein. The hinge is further designed so as to be easily opened so as to spread the cuffs apart. Hinge opening is accomplished through a specialized implant tool, the implant tool being a generally cylindrical tube designed to meet about the lead body. A divergence in the lead body near the hinge permits the implant tool to engage the lead body in that section and thus forces the cuffs apart.

Abstract: A system and method for locating an implantable medical device. The system consists of a flat “pancake” antenna coil positioned concentric with the implantable medical device target, e.g. the drug reservoir septum. The system further features a three location antenna array which is separate from the implantable device and external to the patient. The antenna array features three or more separate antennas which are used to sense the energy emitted from the implanted antenna coil. The system further features a processor to process the energy ducted by the antenna array. The system senses the proximity to the implant coil and, thus, the implant device by determining when an equal amount of energy is present in each of the antennas of the antenna array and if each such ducted energy is greater than a predetermined minimum. When such a condition is met, the antenna array is aligned with the implant coil. Thus the needle port through the antenna array is lined up with the septum of the drug reservoir.

Abstract: A method of modifying the surface characteristics of a substrate having a surface with an amide-functional polymer thereon. The method involves contacting the amide-functional polymer with a source of hydroxide ions and a source of hypohalite ions at a temperature of at least about 20° C. for a time effective to convert at least a portion of the amide-functional groups to amine-functional groups to form a substrate surface comprising an amine-functional polymer, wherein the hydroxide ions are present in a molar excess relative to the hypohalite ions and at a concentration of no more than about 0.1 M, based on the total volume of the reaction mixture. A biomolecule is attached to the resultant amine-functional polymer.

Abstract: A medical electrical lead having a pre-formed atrial portion assuming a distinctive U-shape is disclosed. The U-shaped atrial portion of the lead is configured and dimensioned to cause at least one atrial electrode disposed thereon to be pushed against the right atrial wall or right atrial sinus wall through pushing forces generated by the lead pressing against regions of the heart located near the superior vena cava or the tricuspid valve, and/or through the action of gravity. The lead provides superior coupling of the atrial electrodes thereof to the walls of the right atrium, and may be configured for single pass DDD stimulation of the right atrium and the right ventricle or other portions of the heart such as the coronary sinus or the great cardiac vein.

Abstract: A medical electrical lead and introducer system. The lead is a single pass, dual chamber lead, which features in one embodiment an atrial tine. The introducer system is particularly designed for introduction of single pass, dual chamber lead which has an atrial tine. The introducer system facilitates the introduction of a such lead into a patient's heart while safeguarding the tine from damage due to kinking during lead positioning. The lead is a single pass lead which features an atrial tine while the introducer system is particularly designed for introduction of a such lead into a patient's heart so as to safeguard the tine from damage due to kinking during lead positioning. The lead is designed so as to electrically couple both the atrium and the ventricular chambers of the heart. The lead generally features several lengths each having differing stiffness as well as a pre-formed bend. The lead also features a atrial tine having an electrode at the tip.

Abstract: A method for making a biocompatible medical article, and preferably, a blood compatible medical article, through the use of a copolymer coating. The copolymer coating is synthesized using methacrylate or acrylate monomers with a functional group (primary amino group) for subsequent attachment of heparin. Synthesis of the copolymer coating is carried out using the proper proportion of hydrophobic monomer/hydrophilic monomer/functional monomer in order to optimize the solubility of the copolymer in alcohol, its insolubility in water (before and after heparin coupling), the heparin coupling efficacy and heparin bioactivity. Once the copolymer coating is fashioned, a medical article is coated with it. The coating is thereafter dried and heparin attached. In such a manner the present invention provides for a method for making a biocompatible medical article, and preferably, a blood compatible medical article.

Abstract: A method and apparatus for synchronized treatment of obstructive sleep apnea. In one embodiment such stimulation is provided by an implantable pulse generator, the implantable pulse generator having a stimulation stage to output stimulation pulses to a body structure, a sensing stage to sense the respiratory effort of a patient, and a controller, to coordinate, and preferably to synchronize, the output stimulation pulses with the sensed respiratory effort. The respiratory effort of a patient is sensed through the use of two electrodes disposed such that the diaphragm is positioned between, and the high frequency current is injected from one electrode to the other and the corresponding impedance is measured, the corresponding impedance thus being a function of the diaphragm position, itself indicating the respiratory effort of the patient. In such a manner the present invention permits the delivery of stimulation to be precisely controlled by the actual respiratory effort of the patient.

Abstract: There is provided an implantable system and method for monitoring pancreatic beta cell electrical activity in a patient in order to obtain a measure of a patient's insulin demand and blood glucose level. A stimulus generator is controlled to deliver stimulus pulses so as to synchronize pancreatic beta cell depolarization, thereby producing an enhanced electrical signal which is sensed and processed. In a specific embodiment, the signal is processed to determine the start and end of beta cell depolarization, from which the depolarization duration is obtained. In order to reduce cardiac interference, each stimulus pulse is timed to be offset from the QRS signal which can interfere with the pancreas sensing. Additionally, the beta cell signals are processed by a correction circuit, e.g., an adaptive filter, to remove QRS artifacts, as well as artifacts from other sources, such as respiration.

Abstract: A method for making a biocompatible medical article, and preferably, a blood compatible medical article, through the use of a copolymer coating. The copolymer coating is synthesized using methacrylate or acrylate monomers with a functional group (primary amino group) for subsequent attachment of heparin. Synthesis of the copolymer coating is carried out using the proper proportion of hydrophobic monomer/hydrophilic monomer/functional monomer in order to optimize the solubility of the copolymer in alcohol, its insolubility in water (before and after heparin coupling), the heparin coupling efficacy and heparin bioactivity. Once the copolymer coating is fashioned, a medical article is coated with it. The coating is thereafter dried and heparin attached. In such a manner the present invention provides for a method for making a biocompatible medical article, and preferably, a blood compatible medical article.

Abstract: There is provided a system for regulating ventricular rate in the presence of abnormally high atrial rates, e.g., during episodes of atrial fibrillation. During such an episode, the system, preferably incorporated into an implantable pacemaker, applies subthreshold bursts of stimulus pulses to or proximate to the patient's AV node so as to inhibit conduction of electrical signals through to the ventricle during the bursts. The bursts are timed in relation to the last conducted ventricular signal, and in terms of burst length, to provide a rate of conducted signals through the AV node which results in a substantially regular and reduced ventricular rate. During the inhibition mode of operation, the system monitors to determine the efficacy of inhibition, by tracking the percentage of ventricular senses that occur during the burst periods.

Abstract: A method and apparatus for synchronized treatment of obstructive sleep apnea. In one embodiment such stimulation is provided by an implantable pulse generator, the implantable pulse generator having a stimulation stage to output stimulation pulses to a body structure, a sensing stage to sense the respiratory effort of a patient, and a controller, to coordinate, and preferably to synchronize, the output stimulation pulses with the sensed respiratory effort. The respiratory effort of a patient is sensed through the use of two electrodes disposed such that the diaphragm is positioned between, and the high frequency current is injected from one electrode to the other and the corresponding impedance is measured, the corresponding impedance thus being a function of the diaphragm position, itself indicating the respiratory effort of the patient. In such a manner the present invention permits the delivery of stimulation to be precisely controlled by the actual respiratory effort of the patient.

Abstract: There is provided apparatus and a method for testing to optimally place a deep brain lead, particularly for stimulating the GPi or other deep brain target to treat neurological disorders such as Parkinson's Disease and the like. The invention embraces determining the location of a feedback target such as the motor cortex, the location of the deep brain target, and inserting a test lead along a substantially linear trajectory so as to be able to stimulate both concurrently. The test lead has an electrode at about its distal end for stimulation of the deep brain target, and an electrode adjustably positioned 3-8 cm proximal for stimulation of the motor cortex. When stimulation is applied concurrently through both electrodes, the affected body portion, e.g., limb, can be made to move when and if the deep brain electrode is optimally positioned. The position can be checked during surgical implant of the system, and the lead position adjusted until the optimum position is found.

Abstract: There is provided a system and method for determining, in a DDD or DDD(R) pacing system, when a delivered atrial pace pulse has failed to capture the patient's atrium. Each cycle, following a delivered ventricular pace pulse, or every N cycles a measure of change in QT interval is obtained and compared to stored criteria. When an atrial pulse has achieved capture, the difference in QT from the last beat will be small, normally less than 2 ms. However, if there has not been atrial capture, the delivered ventricular pace pulse is in fact asynchronous with respect to the atrium, and under these circumstances the change in QT is greater than 2 ms, e.g., in the range of 2-10 ms. Accordingly, when the pacemaker sees a change in QT within the 2-10 ms range, this indicates failure of capture, and responsive action is taken by either directly incrementing the energy level of the atrial pace pulses, or performing an atrial threshold search and then resetting the atrial pace energy level.

Abstract: A pacing system and method for providing multiple chamber pacing of a patient's heart, and in particular, pacing programmed for treatment of various forms of heart failure. The system utilizes impedance sensing for determining optimum pacing parameters, e.g., for pacing the left ventricle so that left heart output is maximized. The impedance sensing also is used for determination of arrhythmias or progression of heart failure. Impedance sensing is provided for between selected pairs of the four chambers, to enable optimizing of information for control and diagnosis. In a preferred embodiment of the invention, impedance measurements are obtained for determining the timing of right heart valve closure or right ventricular contractions, and the timing of delivery of left ventricular pace pulses is adjusted so as to optimally synchronize left ventricular pacing with the right ventricular contractions.

Abstract: An anticonstipation apparatus, and method, that may include using an implanted stimulus generator that may supply electrical stimuli to the muscles associated with a target portion of the patient's gut, from the esophagus to the anus, through an electrical lead and several pairs of electrodes. The electrical stimuli may be provided to nerves in the autonomic nervous system that are associated with the muscles, or the stimuli may be provided directly to the muscles themselves. The stimuli may be provided sequentially, in a proximal to caudad direction, in order to initiate, enhance or artificially produce peristalsis in the gut's target portion in a proximal to caudad direction. If the gut's target portion is in the descending colon, such stimulation may be coordinated with similar stimulation of the muscles associated with the rectum and anus. A sensor may be provided to detect when the target portion is experiencing constipation.

Abstract: There is provided a pacemaker system having the capability of providing therapy for preventing conditions likely to lead to myocardial infarction or ventricular arrhythmia during patient morning time. Specifically, a therapy is initiated before calculated patient awakening time, for raising pacing rate slowly so as to shorten QT interval to an acceptable level relative to rate at the time of patient awakening, and specifically a level that achieves satisfactory diastolic filling time. The pre-awakening therapy pacing routine is designed to overcome normal QT prolongation which occurs during sleep state, and which is delayed after patient awakening. In the event that criteria for an acceptable diastolic filling time are not met at or after patient awakening, the pacemaker takes steps to control rate, such as ceasing synchronous pacing and limiting automatic rate response.

Abstract: An introducer system for a lead, catheter, probe or the like, employing a dilator and introducer sheath assembly for dilating a body vessel in preparation for introducing the lead, etc., through the lumen of the introducer sheath that provides for the injection of radiopaque contrast media to observe the cause of an impediment to advancement of the assembly into the vessel lumen. The dilator is formed of an elongated dilator body having a guide wire lumen therein for receiving and being advanced over the guide wire and a hub assembly at the proximal end of the guide wire body. An injection lumen is also formed in the dilator body isolated from the guide wire lumen and in fluid communication with a side port formed in the hub assembly and an injection port formed in the distal end of the dilator body. Preferably, the injection port is formed in a tapered distal end portion of the dilator.

Abstract: A medical device system such as a pacemaker system is provided wherein pressure signals representative of a patient's cardiac movements are transmitted through a pacing lead to the pacemaker, where they are sensed and utilized for control of pacemaker operation. In a preferred embodiment, the invention utilizes a standard pacing lead, which may already be in place within the patient, the lead having a lumen through which relative pressure signals are transmitted from the patient's heart to the proximal end of the lead. The proximal end of the lead is connected to a pressure sensor, mounted either in the pacemaker header portion or within the hermetically sealed pacemaker can. The sensor signals are coupled to appropriate processing circuitry and are used for control of one or more pacing parameters, such as pacing rate.