Abstract: Systems and methods are disclosed to stimulate nerves to treat medical conditions such as pain, and other conditions, such as, CHF, obesity, incontinence, etc., that could be controlled by the stimulation of the vagal nerves. The invention uses electrical stimulation of the nerve, where vibrational energy from a source is received by an implanted device and converted to electrical energy and the converted electrical energy is used by implanted electrodes to stimulate the pre-determined nerve site. The vibrational energy is generated by a controller-transmitter, which could be implanted or located externally. The vibrational energy is received by a receiver-stimulator, which could be located in the various regions on or around the nerve that needs to be stimulated. The implantable receiver-stimulator stimulates different nerves and regions of a nerve to provide therapeutic benefit.

Abstract: Systems for pacing the heart include a vibrational transducer which directs energy at the heart, usually at at least a ventricle, to pace the heart and to promote synchronized contraction of the ventricles. Optionally, additional vibrational and/or electrical stimulation may be provided. The vibrational transducers are usually implantable at a location proximate the heart.

Abstract: Methods and systems for detecting ultrasound transducer failure in an ultrasound catheter system comprise providing a memory device or other data storage element or catheter body having at least one ultrasound transducer disposed. The memory device stores a test current amplitude value which relates to an actual operating peak current for the at least one ultrasound transducer. An average actual operating peak current amplitude during a first period of time is calculated, and an actual operating peak current for the at least one ultrasound transducer over a second period of time may optionally also be calculated. Transducer failure has occurred if the actual operating peak current amplitude passes outside of a fit preferred range during the firs period of time, or the actual operating peak current amplitude passes outside of a second preferred range during a second period of time.

Abstract: A wide beam ultrasound delivery system providing a uniform exposure field is used to enhance the uptake of injected substances and/or to enhance the transfection of DNA in the tissues of human subject, or reduce the amount of vascular intimal hyperplasia in human subjects following vascular injury.

Abstract: A wide beam ultrasound delivery system providing a uniform exposure field is used to enhance the uptake of injected substances and/or to enhance the transfection of DNA in the tissues of human subject, or reduce the amount of vascular intimal hyperplasia in human subjects following vascular injury.

Abstract: A method of treating a target region in a body lumen, said method comprising: directing a uniform dose of ultrasonic energy from an interior of the lumen radially outward over a treatment length of the lumen, wherein the dosage of ultrasonic energy received at any one point along the length varies by no more than plus or minus 6 decibels from that received at any other point along the length.

Abstract: A method of treating a target region in a body lumen, said method comprising: directing a uniform dose of ultrasonic energy from an interior of the lumen radially outward over a treatment length of the lumen, wherein the dosage of ultrasonic energy received at any one point along the length varies by no more than plus or minus 6 decibels from that received at any other point along the length.

Abstract: A method of treating a target region in a body lumen, said method comprising: directing a uniform dose of ultrasonic energy from an interior of the lumen radially outward over a treatment length of the lumen, wherein the dosage of ultrasonic energy received at any one point along the length varies by no more than plus or minus 6 decibels from that received at any other point along the length.

Abstract: Pressure transducer circuitry accommodating pressure transducer variables for making pressure measurements in a living body. A microminiature piezoresistive pressure transducer has first and second variable resistive elements. The pressure transducer is characterized as having a pressure sensitivity ranging from 1.2 to 15 ohms per 1,000 ohms per 100 millimeters of mercury and a temperature characteristic greater than pressure sensitivity. Circuitry is coupled to the first and second variable resistive elements of the transducer including a known fixed resistive element. The known fixed resistive element is coupled to the first and second variable resistive elements for supplying a transducer excitation voltage through the known fixed resistive element to the first and second variable resistive elements. First and second amplifiers each having an input and an output are provided.

Abstract: Piezoresistive pressure transducer circuitry accommodating transducer variables comprising microminiature pressure transducer having first and second variable resistive elements each having first and second ends, circuitry coupled to the first and second resistive elements of the transducer including third and fourth fixed resistive elements each having a first and second ends, means interconnecting the first ends of the first and second resistive elements, means interconnecting the second ends of the first and third resistive elements, means interconnecting the second ends of the second and fourth resistive elements, means interconnecting the first ends of the third and fourth resistive elements, means for supplying excitation to the first ends of the third and fourth resistive elements, first amplifier means having an input coupled to the means interconnecting the second ends of the first and third resistive elements, second amplifier means having an input coupled to the means interconnecting the second end

Abstract: Apparatus for measuring volumetric flow of a liquid in a vessel having a wall and having an axis extending longitudinally of the vessel parallel to the vessel wall. A flexible catheter is adapted to be disposed in the vessel. First and second ultrasonic transducers are carried by the catheter on one side of the catheter and face the wall of the vessel so that the beams from the transducers each cross substantially the longitudinal axis of the vessel. The first transducer beam is inclined at an angle with respect to the longitudinal axis of the vessel. The second transducer beam is inclined in a direction which is generally perpendicular to the longitudinal axis of the vessel.

Abstract: Apparatus for measuring volumetric flow of a liquid in a vessel having a wall and having an axis extending longitudinally of the vessel parallel to the vessel wall. A flexible catheter is adapted to be disposed in the vessel. First and second ultrasonic transducers are carried by the catheter on one side of the catheter and face the wall of the vessel so that the beams from the transducers each cross substantially the longitudinal axis of the vessel. The first transducer beam is inclined at an angle with respect to the longitudinal axis of the vessel. The second transducer beam is inclined in a direction which is generally perpendicular to the longitudinal axis of the vessel.