Abstract: The invention relates to a fluid pressure sensor for a lead (18) or catheter preferably intended to be placed in a living organism, such as the heart of a human being, said sensor comprising a piezoelectric element (4, 10, 11, 14) delivering an electric signal when subjected to a pressure variation, said piezoelectric element (4, 10, 11, 14) being designed to exhibit circumferential sensitivity and being disposed on at least parts of the outer surface of a rigid annular or tubular supporting structure (2). The rigidity of said sensor is such that the signal from the sensor relating to the pressure transferred to the sensor through an ongrowth of for instance tissue on the sensor would be at least 90% of the signal from the sensor without the ongrowth.

Abstract: In an implantable intravascular pressure determining device and method, a pressure sensor generates a raw pressure signal, an acceleration sensor generates an acceleration signal, and an evaluation unit determines a disturbance pressure signal from the acceleration signal. A processed signal is generated as the difference between the raw pressure signal and the disturbance pressure signal. The processed signal corresponds to intravascular pressure.

Abstract: A medical implant has an element with at least a part thereof which is composed of piezoelectric material. The piezoelectric material is suitable for contact with body tissue and/or body fluids, and has the formula NaxKyNbO3, with 0≦x≦0.8, 0.2≦y≦1, and x+y=1.

Abstract: In an implantable intravascular pressure determining device and method, a pressure sensor generates a raw pressure signal, an acceleration sensor generates an acceleration signal, and an evaluation unit determines a disturbance pressure signal from the acceleration signal. A processed signal is generated as the difference between the raw pressure signal and the disturbance pressure signal. The processed signal corresponds to intravascular pressure.

Abstract: In an implantable intravascular pressure determining device and method, a pressure sensor generates a raw pressure signal and an acceleration sensor measures acceleration in a patient. Time intervals are identified wherein the raw pressure signal accurately represents the intravascular pressure, these intervals being identified as the time intervals wherein the measured acceleration is below a predetermined threshold. The raw pressure signal is processed, to generate a processed signal which is used as an intravascular pressure signal, only in the aforementioned time intervals.

Abstract: A biocompatible medical implant has at least one part thereof composed of ceramic material with the formula NaxKyNbO3, wherein 0≦x≦0.8, 0.2≦y≦1, and x+y=1. The ceramic material can be polarized to give the implant spatially varying piezoelectric properties. Signals can be measured from the respective piezoelectric regions of the selectively polarized ceramic material to provide an indication of the degree of fixation of the implant to surrounding tissue.

Abstract: In an implantable electrode for an electrode lead for a stimulation device for stimulating tissue, the electrode is formed as a biocompatible piezoelectric electrode which is adapted to be in direct electrical contact with tissue for electrically and mechanically stimulating the tissue and for detecting electrical and mechanical evoked response of the stimulated tissue. The stimulation device can include circuitry for making a diagnosis of a heart condition using signals received from the implantable electrode.

Abstract: The present invention refers to a method and a device for jetting droplets of a viscous medium onto an electronic circuit board. According to the invention, the viscous medium is applied from a viscous medium supply container to an eject chamber through a tubular passage using a rotatable feed screw arranged within the tubular passage. The viscous medium is then jetted from the eject chamber through an eject nozzle by the rapid decreasing of the volume of the chamber.

Abstract: An implantable medical device has a pressure sensing arrangement to measure right ventricular pressure of a heart including a pressure sensor adapted to be positioned in the right ventricle of the heart, to measure the pressure and to generate a pressure signal in response to the measured pressure. The pressure sensing arrangement also has a pressure signal processor and a timing unit. The processor determines from the pressure signal, using diastolic timing signals from the timing unit based on the pressure signal identifying the diastolic phase, a diastolic pressure signal representing the ventricular pressure only during the diastolic phase of the heart cycle.

Abstract: An accelerometer has a cantilevered beam supported at one end and having an opposite free end, with an inertial, sensing mass mounted at the free end of the beam. The beam is formed of a piezoelectric layer and a supporting layer. The ratio of the thickness of the piezoelectric layer relative to the thickness of the supporting layer is in a range between 2 and 4. The ratio of the modulus of elasticity of the material forming the supporting layer relative to the modulus of elasticity of the material forming the piezoelectric layer is in a range between 8 and 12.

Abstract: An implantable medical device has a housing containing an accelerometer which detects vibrations of the housing. The accelerometer generates a vibration signal in response to the detected vibrations, which is supplied to a signal processing unit. The signal processing unit generates, for each of a number of predetermined frequency ranges, a parameter value indicative of a defined attribute of the vibration signal. The signal processing unit forms a ratio between any two of these parameter values, and emits at least one status value dependent on this ratio. The status value is uniquely indicative of a predetermined type or level of cardiac activity, and the status values can be used as a control signal for controlling therapy, such as cardiac stimulation, administered by the implantable medical device.

Abstract: An implantable electrode for stimulating tissue has a piezoelectric electrode for electrically and mechanically stimulating tissue and for detecting electrical and mechanical evoked response of the stimulated tissue. An implantable lead and an implantable stimulation device employing such an electrode are described including diagnostic circuitry for making a diagnosis of the heart condition using such an electrode.

Abstract: An implantable medical device for in vivo electrochemical measurements of blood properties, such as measurements of, inter alia, oxygen pressure, glucose and pH, avoids the problem with the reference electrodes currently in use which cause inflammatory reactions of tissue, by forming the reference electrode of carbon, preferably activated pyrolytic carbon.

Abstract: In a magnetic field detector as well as in a combined telemetry and magnetic field detector unit in a medical implant, a magnetic field sensor with a coil and a diode are employed for determining the presence of a magnetic field. For making such a determination, the coil is charged by a source of voltage for a defined period of time, the time for the discharge of the coil through the diode depending on whether a magnetic field is present. A detection signal indicating the presence of a magnetic field is generated if the discharge time is less than a defined time threshold value.

Abstract: In a magnetic field detector as well as in a combined telemetry and magnetic field detector unit in a medical implant, a magnetic field sensor with a coil and a diode are employed for determining the presence of a magnetic field. For making such a determination, the coil is charged by a source of voltage for a defined period of time, the time for the discharge of the coil through the diode depending on whether a magnetic field is present. A detection signal indicating the presence of a magnetic field is generated if the discharge time is less than a defined time threshold value.

Abstract: A combined telemetry and magnetic field detector unit for use in a medical implant includes control logic, a magnetic field indicator, a telemetry circuit containing a number of switches, and a coil unit. The control logic is arranged to operate the switches such that switching between the telemetry function and the magnetic field detection function of the combined unit is achieved so the coil unit is utilized for transmission of telemetry signals to and from a programmer as well as for magnetic field detection. For magnetic field detection, the coil unit, which consists of multiple parts, is connected by the control logic such that the parts respectively form a primary side and a secondary side of a pulse transformer, with the magnetic field indicator connected by the control logic to the pulse transformer's secondary side.

Abstract: Matrix printer means having plurality of write heads. In order to be able to achieve a print width in matrix printer means that is greater than that of an individual write head and in order to simultaneously enhance the resolution beyond the basic resolution of the write head or in order to enable multi-color printing, a plurality of rows of write heads are provided. The neighboring write heads in one row and the rows themselves are arranged phase-shifted relative to one another or the colors of the write heads in every row and between the rows are cyclically interchanged. The plurality of required rows of write heads is thus reduced to a minimum.

Abstract: An activity sensor wherein a piezoelement of the flexural type is employed. The activity sensor avoids a depolarization even given great mechanical stresses and simplifies the contacting of such a sensor regardless of the surfaces to which it is applied. It is provided in accord with the invention that the piezoelement is composed of two individual or inter-related piezoceramic parts arranged side-by-side which are oppositely polarized and are provided with electrodes on both sides. On one side, the electrodes are electrically connected to one another and, on the other side, are connected to terminals.

Abstract: A method and apparatus for increasing inking resolution in an ink-mosaic recording device. In order to increase the inking resolution in a simple manner, a recording head is periodically deflected transversely to a direction of ejection of the drop of fluid, and the ejection is synchronized with this deflection. Thus a transverse speed component may be superimposed on the drop so that an encountering point on the recording carrier is shiftable. With a same number of transducers and constant transducer spacing, the recording points may be positioned closer to one another.

Abstract: In order to significantly intensify the pump action in a piezoelectric pump without long-term, negative consequences, and in order to be able to employ a great variety of fluids, the pump of the invention is formed of piezoceramic parts arranged essentially parallel to and at a distance from one another. They are provided with electrical contacts at both sides, and are covered at both sides with closure means. The cavity between the piezoceramic parts and the closure means forms the pump channel. The electrical contacts lie essentially perpendicular relative to the closure means. The polarization direction in the piezoceramic parts lies parallel to the electrical field strength. A multi-channel pump, particularly for an ink-jet matrix printer means, can be manufactured in an especially simple way by use of known semiconductor manufacturing techniques.