Patent DE-19853035-A1 (DE)
Title: Portable appts for injection or infusion
Inventor: CHO OK-KYUNG
IPC: A61M5/172
Filed: 1998-11-18
Abstract: The portable appts. to deliver a time-delayed liquid medication, by injection or infusion, has a reservoir (2) which is shaped so that, at each level, the boundary surface is small between the liquid and the already emptied vol. of the reservoir. The reservoir is inserted directly into the body as a hose or tube, or formed by the hose or tube.  The reservoir has small outer dimensions, and is wound into a spiral or a coil.  It can also be a flat and compact unit in three dimensions, with a number of internal intermediate walls. The inserted end (6) into the body is tapered or chamfered, curved or angled.  An insertion aid and a dividing membrane are partially within the reservoir. A moving ball within the reservoir acts as a limit, at the liquid level, and bears against an obstacle or a limit before the reservoir is wholly emptied, to prevent more liquid flowing out. Chemicals are used to displace the liquid from the reservoir and/or to trigger a speed control for the displacement using self-foaming materials or light volatile substances, or biologically active matter such as enzymes or micro organisms. The displacement is triggered by a circuit which breaks down a chemical substance by heat, on a timed basis, and release a gas or swell the substance to increase its vol. The liquid is drawn out of the reservoir by a micro pump, and pref. a membrane micro pump (4), or directly or indirectly by a solid or liquid or gas propellant. A buffer or propellant and a passage are at the delivery unit.  The passage allows a limited vol. of buffer medium to pass through per time unit.  The buffer medium is a pump gas such as oxygen or nitrogen, in a pressure vessel. The reservoir is closed at its trailing end.  The leading end of the reservoir, inserted into the body, has an element which is permeable to gas but impermeable to liquids, to allow any pump gas residue to disperse. A differential pressure sensor registers the pressure drop in the supply liquid or buffer or propellant media, measured through a capillary or a suitable narrowed point.  The output signal from the differential pressure sensor is used for the control of a given. vol. feed per time unit. The passage has one or more openings as micro or nano jets, diaphragms, or one or more micro or nano pore membranes, or one or more diffusion membranes, or one or more active bio-membranes. The buffer medium is moved or transported by a medium, directly or indirectly by over- or underpressure, such as pumped or displaced.  A mechanical system moves the buffer medium as a piston which, on reaching a given position, releases a barrier in a closed link to the reservoir.  The piston is moved by a mechanical force through an over- or underpressure, by an electrical or magnetic force, or by one or more chemical reactions.  The piston is of a solid material, or of a gel or brine or a liquid material, or it is of the liquid which is being delivered.   The passage has at least a selective permeability, so that the piston material cannot pass through.  The material with selective permeability is at the end of the piston stroke or the wall of the piston housing, so that the delivered liquid can pass through while the buffer medium is wholly or mostly retained.  The material with a selective permeability is of pore membranes, dissolving/diffusion membranes, or active bio-membranes or other active membranes. The appts. is a single component group, forming the reservoir and the delivery unit. At least one sensor generates an output signal to control the vol. of delivered liquid.  The sensor registers temp. or heat, of the individual biological clock of the patient, for the liquid to be delivered by measurements of the body temp. over a long time span.  The sensor is linked to a pulse sensor, which measures the patient's pulse rate through one or more microphones or electrodes to measure the cardiac or other blood streams. At least one sensor is a blood supply sensor such as an induction current or induction voltage sensor, a thermal sensor or one or more optical sensors at suitable body points in the transmission and/or scattered light geometry.  At least one sensor is a glucose sensor. The sensors for temp., blood pressure, pulse frequenc