Siemens Aktiengesellschaft

Karl Prestele

Manfred Franetzki

Volker Korn

Klaus Gagneur

Richard Ernst Soldner

Helmut Funke

Erich Reif

Electrical components, such as filters, oscillators, resonators and delay lines are manufactured from a piezo ceramic base which includes a depolarized zone. The sound velocity is set by topically heating a portion of the base to form the depolarized zone between a pair of transducers.

Electro-acoustic component of piezo ceramic material and method for

An acoustic delay line includes electrodes on a monolithic piezoceramic substrate, which serve as electro-acoustic transducers for the delay line. The distance between said transducers defines the transit time, and thus the delay path. Each transducer may have electrodes on the same side of the substrate, in which case thickness of the substrate is less than or equal to one-half the wavelength of the highest frequency to be transmitted in the substrate, so as to prevent the formation of higher modes. Alternatively, each transducer may have congruent electrodes on opposite sides of the substrate, in which case the thickness of the substrate is less than or equal to the wavelength of the highest frequency to be transmitted. The substrate is polarized substantially parallel to the equipotential lines which arise in the substrate upon the application of a voltage to the electrodes. The acoustic wave which is generated by one of the transducers therefore traverses the delay path between said transducers as a plate shear wave. High-precision broadband and distortion-free delay lines can thus be realized for low frequencies, with small component dimensions despite long delay times.

Piezoceramic lamina acoustic delay line suitable for use in an

The invention relates to an apparatus for the administration of medications. The apparatus includes a safety system which prevents a harmful overdose when the person using the apparatus is unable to take action. For this purpose, the safety system initiates a safety measure, (such as turning off the dosing unit, switching the dosing unit to a reduced administration rate (so called 'emergency rate') and/or setting off an alarm) in the event that a checking procedure is not triggered by the patient within a predetermined time interval or after the administration of a specific quantity of medication. Starting times based on the time of day and generated by a master clock can be pre-pregrammed, for example, as a reminder to the patient to eat. In insulin therapy, the apparatus prevents a patient from becoming hypoglycemic as the result of a long lasting insulin overdose, for example, during sleep.

Device for the administration of medications

The invention relates to a method and a device for flow measurements of small liquid volumes through a thin tube. The measurement of small liquid volumes on the order of e.g. 1-500 .mu.l/h is important, especially for medication dispensers. Gas bubbles are fed into the tube, the diameter of the gas bubbles being essentially the same size as the inside diameter of the tube. The liquid flow pushes the gas bubble forward. The flow time of the gas bubble is determined at pre-set measuring points which are located at a predetermined distance from each other along the tube. A control signal may be emitted according to the flow time and may be used to control the flow rate. The method and the device are suitable for electrically conductive liquids, in which variations in the electrical resistance is determined in the direction of the flow when the bubbles enter the measuring section.

Method and device for flow measurement of small liquid volumes

Particularly for diabetes therapy, it is desirable to continuously infuse insulin in different rates into the body of the patient, because the insulin requirements of the diabetic are subject to great fluctuations. Therefore, a control device serves as the program transmitter for a microdosing unit. The control device for the microdosing unit has memory means for a prescribable control program allocated to it, whereby the control program can be called up directly by the patient at the control device. The program sequence of the infusion is started only by means of the dialing-up of a plurality of insulin units to be delivered into the body or of relevant food values taken in by the patient with a meal and of a starting time (T.sub.1, T.sub.2). In addition, specific base rates of the infusion can be selected by the patient. With the invention device, diabetes patients can call up the necessary insulin administration according to short programs at meals.

Device for the pre-programmable infusion of liquids

The exemplary embodiments relate to a device housing implantable in the body and having a reservoir for the infusion of fluid and having a conveying and dosing unit for conveying the fluid from the reservoir to the discharge opening of a discharge catheter. In known devices of this type, the reservoir is held at a reference pressure which is lower in comparison to the pressure at the fluid discharge location in order, in case of a defect, to prevent fluid from flowing out. According to the present disclosure, pressure equalization between the inside space of the housing and the environment is effected for example by a hydrophobic or hydrophilic diaphragm with pores of a specific size or a diffusion diaphragm in combination with a pressure control valve in the wall of the device housing.

Infusion device intended for implantation in a living body

An exemplary embodiment comprises a metering device which can be worn on the body or which is preferably implantable in the body, the metering device exhibiting a delivery unit for the dosed delivery of the fluid from a supply container to a discharge aperture of a catheter and also exhibiting an appertaining operating circuit, and an external control and programming device. The operating circuit in the metering device and the control circuit in the control device can be inductively coupled for operational signal transmission, to which end at least one transmission coil is present in the control device and at least one reception coil is present in the metering device. Given implanted devices, it is the object of the disclosure to guarantee the highest degree of patient security. For function monitoring of operating parameters of the metering device the metering device exhibits a transmitter whose signals can be received in a receiver outside of the patient's body and, under certain conditions, can be evaluated. In addition to pure function monitoring, an acknowledgement of signals as well as an answerback of the value of one or more operating parameters is possible.

Device for the infusion of fluids into the human or animal body

Particularly for diabetes therapy, it is desirable to continuously infuse insulin in varying installments into the body of the patient. A control device serves as a program transmitter for a microdosing unit. The physician should be able to pre-program the daily profile of the infusion and, if necessary, to change it. According to the disclosure, at least the control device for the microdosing unit has memory means for a prescribable control program allocated to it, whereby the control program is pre-programmable in discrete time steps by an external programming device corresponding with a 24 hour daily sequence. The control device is detachably connected directly with the programming device or is coupled therewith by means of a program carrier or a programmed memory chip solely for a rapid transfer of the pre-programmed control program into the internal memory means of the control device. Thus the control device is particularly adapted for the adjustment of diabetes patients to an optimum daily profile of insulin administration outside of a hospital setting.

In the illustrated embodiment, applied high frequency flow is divided into a first flow component traversing a known flow impedance and a second flow component directed toward the mouthpiece of a breathing tube. During calibration, the mouthpiece is sealed, and phase adjustments are made such that during measurement, applied flow and first flow component representing signals are essentially in phase and can be combined in an a.c. subtracter to provide a measure of the second flow component. A divider provides the quotient of rectified average pressure and second flow component signals as a measure of the magnitude (Z) of respiratory passageway impedance. A phase difference measurement circuit measures the phase difference between pressure and second flow components and can be switched over during calibration for use in the phase adjustment procedure. The real and imaginary components of respiratory passage impedance can be obtained using sample and hold circuitry responsive to the phase of the second flow component.

Apparatus for the determination of the respiratory passageway impedance

An apparatus for infusion of liquids into human or animal bodies which comprises a liquid reservoir having a reduced-pressure generating means associated therewith and an active delivery-dosing means, such as a roller pump, operationally coupled with the reservoir and with an outflow catheter having outflow opening within the body being infused. The reduced-pressure generating means, such as a volatile fluid, for example, a halogenated hydrocarbon, maintains a pressure at the point of connection between the reservoir and the active delivery-dosing means at a reference value which is lower than the pressure prevailing at the outflow opening of the outflow catheter.

Apparatus for infusion of liquids

An apparatus for the determination of the respiratory passageways resistance, including a flow resistance in the breathing or respiratory flow passageway, whose resistance value is periodically varied by a frequency which lies above the breathing frequency, and including as well a pressure and/or, as occasioned, a flow measurement gauge. In conjunction with the flow resistance, the resistance value thereof is varied in an essential sinusoidal manner, and the pressure and/or flow measurement gauge incorporates two measuring passageways, there being detected in the first passageway only the pressure and/or occasioned flow components in the respiratory passageway due to the lower frequencied breathing, and in the second passageway the higher frequencied resistance variations.

Apparatus for the determination of respiratory passageway resistance

An apparatus for the determination of the respiratory passageway resistance, including a breathing tube which incorporates a flow resistance and a pulse generator for subjecting the breath flow to higher frequency pressure or, respectively, current pulsations, as well as a pressure gauge for measuring the pressure in the breathing tube. The pressure gauge is constituted of an alternating pressure gauge coordinated with the pulsating frequency of a pulse generator. As alternating pressure gauge there may be utilized a common mechanical-electrical transducer which, for detection of the alternating pressure, has an electrical frequency filter connected thereto.

Apparatus for determination of respiratory passageway resistance

An apparatus for the determination of the respiratory passageway resistance. Apparatus of that type in general evidence a flow resistance located in the respiratory passageway, whose resistance value is periodically varied at a frequency which is located above the breathing frequency, or a breathing tube with a flow resistance and a pulse generator for subjecting the breath flow with higher-frequencied pressure- or, respectively flow pulsations.

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Erlangen, Germany

Karl Prestele