Bernd Granz

Ultra-sound sensor

The ultrasound sensor (2) of the invention comprises a polymer foil (4) which is supported in its outer region and is piezoelectrically activated at least in one portion (42). The portion (42) is coupled electrically to a first electrode (200) in the form of an adjacent, i.e., touching pin. A second electrode (8), in the form of a grid (214) connected to ground and/or a ring (216) connected to ground, is physically separated from the activated portion (42). The pin (200) is connected to the first input of an amplifier (210). The second input thereof is connected to ground. The metallic take-off at the activated zone (42) results in high sensitivity of the ultra-sound sensor (2) which is provided particularly for the measurement of shock waves with a high pressure amplitude and which finds application in lithotripsy.

Device for the spatial ultrasonic location of calculi

The invention relates to a device for the spatial, ultrasonic location of concrements found in the body of a living being, which are to be located at the focus of an ultrasonic shock wave so as to be destroyed in a lithotritor. According to the invention, an ultrasonic camera, which works in the reflection mode, is provided for the ultrasonic location procedure focal region which is adjusted to an object plane, which contains the focus of the ultrasonic shock wave. In this way, information from sectional planes of the body can be made available to the user, making it easier to position the concrement securely in the focus of the ultrasonic shock wave.

A Linear Monolithic Receiving Array of PVDF Transducers for Transmission Cameras

Linear receiving arrays with ten transducer elements made of the piezoelectric polymer PVDF were constructed and the performance measured. The single transducers in the monolithic array are defined by standard photolithography and selective poling the remaining metallized 0.7x0.8 mm2 spots. The 25µm PVDF foil is glued on to a hard backing to get increased sensitivity. The result we found was a sensitivity of 2· 10-6 Vm2/N and a broad band behaviour from 2 to 12 MHz. The interelement coupling was found to be about -35 dB. The angular acceptance was nearly ideal except narrow minima depending on the backing material.

Comparison of Light Spot Hydrophone (LSHD) and Fiber Optic Probe Hydrophone (FOPH) for Lithotripter Field Characterization

Characterization of the acoustic field of a shock wave lithotripter is important for determining the performance of the device. In this study, we compare the performance of a newly developed Light Spot Hydrophone (LSHD) with the current standard, i.e., the Fiber Optic Probe Hydrophone (FOPH). An electromagnetic (EM) shock wave lithotripter was selected and each hydrophone was used to map the acoustic field of the lithotripter. The peak positive pressure P+, peak negative pressure P−, pulse duration, and effective acoustic energy were calculated using the collected data. Both the LSHD and the FOPH have similar measurement characteristics. They both provide excellent P+ measurement accuracy and response. Although the LSHD was found to provide more repeatable P− pressure measurements, both devices provide excellent pressure measurement of lithotripter shock fields.

In Vitro Comparison between HM‐3 and MODULARIS Lithotripters

Shockwave lithotripsy (SWL) is currently the preferred method of treatment for renal calculi < 10 mm in size. Dornier introduced the electrohydraulic HM‐3 in 1983, which has become the “gold standard” for SWL. Since then other types of lithotripters (electromagnetic and piezoelectric) have been developed. We compared the third‐generation electromagnetic shockwave lithotripter Siemens MODULARIS to the HM‐3 in vitro assessing acoustic measurement and stone comminution in a holder. Similar results were encountered.

Ultrasound transmitting configuration

An ultrasound transmitting configuration includes at least one ultrasound generating device for exposing a medium which has an acoustic medium impedance and a medium speed of sound to ultrasonic waves. The ultrasound generating device has at least two ultrasound transducers which can be excited through actuating electrodes for emitting ultrasound and which have an acoustic transducer impedance. The ultrasound transducers are separated from one another and disposed alongside one another. An ultrasound lens which has an acoustic lens impedance and a lens speed of sound is disposed between the ultrasound generating device and the medium. The ultrasound generating device is acoustically coupled on a coupling side to the ultrasound lens. The ultrasound transducers extend toward the medium over a transducer depth, they extend toward one another over a transducer width, and they extend at right angles to both the transducer depth and the transducer width over a transducer length. The transducer width is maximally as great as the transducer depth, and the transducer length is considerably greater than the transducer depth. The ultrasound transducers are associated with a common actuating element for actuating the ultrasound transducers jointly and in the same way.

Neue Impulse für die Ultraschall-Transmissionskamera

The ultrasonic transmission procedure is presented and compared to the B-Scan method. As a diagnosis tool ultrasound transmission cameras show excellent real-time images of tendons and ligaments with their skeleton connection during their natural movement. The picture is orthographic with good lateral resolution in both dimensions and easy to interprete. Clinical studies in surgery, orthopedics and rheumatology exhibit the good application for specific clinical questions. A novel ultrasonic transmission system will be presented. It consists of two crosswise arranged 1-D ultrasound arrays with focusing means. 2-D resolution in the object plane is achieved by exciting only a line with the transmit array while reading out only a perpendicular row with the receive array. This results in an advantageous combination of a large field of view and a low-cost technology. Für die Dokumentation Ultraschall / Transmission / Kamera / Abbildung / Diagnose / Rheuma

Ultrasonic imaging of extremities by immersion technique

Hands, arms, and legs immersed in a water bath can be imaged by the complementary methods of reflection and transmission mode. The two system configurations and their related image processing are described. The reflection system collects B-scans from many directions and generates geometrical cross sections as well as spatial distributions of physical parameter in the insonified tissue by applying computer tomographic principles. Regions of interest can be investigated interactively with reduced resolution. Planes perpendicular to the cross section are imaged by the transmission system. Its key element is a large, electronically scanned matrix of receivers. Because of its fast video frame rate, the function of tendons and joints can be inspected during natural movements.<<ETX>>