Abstract: An implantable dispensing device for delivering a treatment agent to a body including a body fluid in which a variable permeability membrane responds to changes in an electro-magnetic parameter in order to vary the rate at which a hygroscopic media increases in volume, thereby controlling the rate of delivery of a treatment agent, such as a drug.

Abstract: A catheter having a microtextured exterior surface portion is employed to deliver fluids such as medicaments internally to the parenchyma of an organ or other internal living bodily tissue. The microtextured exterior surface portion promotes cellular tissue ingrowth into the textured surface, thereby creating an effective fluid seal in the bore formed in the tissue and inhibiting the body's rejection response to the catheter. The fluid seal prevents the reflux of infused fluid from the distal end of the catheter from the bore opening and permits controlled delivery of fluid to affected tissue.

Abstract: The present disclosure describes a catheter that has minimal dead volume due to a "micro" or very small internal diameter for the majority of its length. In addition, however, the distal tip of the catheter, which is the end inserted into the body proximate the location at which the pharmaceutical agent or other fluids are to be delivered, includes a chamber, compartment or other relatively wider internal diameter section, so that the internal diameter rapidly expands in the transitional region between the proximal portion of the catheter (with the very small or micro internal diameter) and the distal portion of the catheter (which includes the catheter tip). The expanding internal diameter causes the velocity of fluid being delivered to decrease prior to its ejection through a distal opening. Also disclosed is a fluid delivery system comprising a stylet lumen separate from a delivery lumen.

Abstract: An implantable catheter defining a plurality of fluid exits responsive to a first range of pressure on a fluid agent for delivering substantially the same flow rate of the agent through each of the exits into spaced infusion sites and responsive to a second range of pressure less than a threshold pressure on the agent for inhibiting the flow of the agent from any of the exits into any of the sites. A first pressure in the first range is applied to the agent in the catheter for a first time period and a second pressure in the second range is applied for a second time period to the agent in the catheter so that substantially the same dosage of agent can be applied to each of the sites.

Abstract: An implantable lead having a body defining an uneven outer surface and a wire carried by the outer surface to form convolutions arranged so that portions of each convolution are displaced from the outer surface. The body may include a hollow core which carries beads so that stretching in the direction of a central axis is inhibited and drug infusion is facilitated. Alternatively, the body may take the form of a helix so that stretching of the lead in the direction of the central axis is facilitated.

Abstract: A novel flexible and highly fatigue resistant neural lead is provided having a body with multiple lumens, one of which may receive a stiffening stylet, and the others of which serve as conduits for bundle stranded wire conductors which make contact with ring electrodes at the distal end of the lead. The ring electrodes will be constructed according to a novel technique in which the body of the lead is etched or milled to provide notches and the ring electrodes are formed by enplacing a C-shaped conductor over the notch and closing it into place to provide an isodiametric lead construction.

Abstract: A heart pacemaker including a two wave length reflectance oximeter for determining oxygen saturation. The pacing rate is increased or decreased in response to the measured oxygen saturation. By appropriate multiplexing and timing functions, the two wave length reflectance oximeter is included in a pacing lead coupled to the pacemaker which requires only three conductors.

Abstract: A heart pacemaker including a two wave length reflectance oximeter for determining oxygen saturation. The pacing rate is increased or decreased in response to the measured oxygen saturation. By appropriate multiplexing and timing functions, the two wave length reflectance oximeter is included in a pacing lead coupled to the pacemaker which requires only three conductors.

Abstract: A heart pacemaker including a two wave length reflectance oximeter for determining oxygen saturation. The pacing rate is increased or decreased in response to the measured oxygen saturation. By appropriate multiplexing and timing functions, the two wave length reflectance oximeter is included in a pacing lead coupled to the pacemaker which requires only three conductors.

Abstract: An enclosure for electronics, particularly adapted for implantation in the human body. The enclosure is provided with at least one transparent wall allowing it to be used in applications requiring light emission or light detection such as reflectance oximeters. The mechanical elements of the enclosure are particularly adapted to facilitate the use of welding to provide a hermetic seal for the enclosure.

Abstract: A cardiac output monitor of the type including an ultrasound crystal for use as a doppler flowmeter. The monitor is designed for mounting directly to a blood vessel, and is provided with a novel fixation apparatus which allows for easy and secure attachment to the blood vessel. The fixation apparatus includes two parallel fixation wires especially adapted for location in the blood vessel wall, without the danger of piercing the vessel wall.