Flow Measurement

Abstract

The present invention relates to flow measurement. To provide improved flow measurement, a sensor 10 for flow measurement is provided, comprising a transducer arrangement 12 having at least one first transducer component 14 and at least one second transducer component 16. The at least one first transducer component and the at least one second transducer component are arranged to have at least partially a common field of view during operation. The at least one first transducer component and the at least one second transducer component are configured to be operated with a phase shift.

Description

[Technical field]

[0001] The present invention relates to flow measurement, and in particular to a sensor for flow measurement, a flow measurement device, an ultrasonic imaging system for flow measurement, a drive circuit for operating a sensor for flow measurement, and a method for flow measurement. [Background technology]

[0002] To measure blood flow in blood vessels, devices such as the Flowwire, which has a small piezoelectric transducer at the distal end of an elongated body, are used. Based on the Doppler ultrasound principle, the Flowwire provides blood flow velocity based intravascular measurements. The measured Doppler frequency shift is converted to the blood flow velocity distribution in the artery. The small piezoelectric element is connected to a console by a long wire. However, it has been shown that effects such as low signal-to-noise ratio (SNR), insufficient bandwidth and resonance frequency variation can result in poor measurement quality. Summary of the Invention [Problem to be solved by the invention]

[0003] There is a need to provide flow measurements with improved accuracy. [Means for solving the problem]

[0004] The object of the present invention is solved by the subject matter of the independent claims, further embodiments are incorporated in the dependent claims. It is noted that the below described aspects of the present invention also apply to a sensor for flow measurement, a flow measurement device, an ultrasonic imaging system for flow measurement, a driver circuit for operating a sensor for flow measurement and a flow measurement method.

[0005] According to the present invention, a sensor for flow measurement is provided. The sensor has a transducer arrangement with at least one first transducer component and at least one second transducer component. The at least one first transducer component and the at least one second transducer component are arranged to have at least a partially common field of view during operation. The at least one first transducer component and the at least one second transducer component are configured to be operated with a phase shift.

[0006] The effect is to provide an ultrasound transducer with an increased aperture angle, i.e. an increased viewing angle or increased field of view, e.g. the measured volume and therefore the measured velocity profile across a blood vessel in blood flow is larger.

[0007] The increased aperture angle, also called acceptance angle, is suitable for large diameter vessels. With a single transducer, due to diffraction effects, the acceptance angle may be, for example, about 25° to 30°, but the increased field of view according to the present invention provides the advantage that in applications with large vessel diameters, flow wires, or other devices to which the sensor is attached, the measured flow velocity is mainly based on measurements that include the vessel wall within the field of view or imaging path of the ultrasound transducer elements, and / or the measured blood flow velocity value is less dependent on the blood flow profile across the cross section of the vessel. Thus, low signal quality results are avoided by the larger acceptance angle of the transducer.

[0008] According to one example, the second transducer component is annularly disposed on the first transducer component. In one example, the first transducer component and the second transducer component are concentrically disposed.

[0009] According to one example, the first transducer component is provided as a first ring-shaped structure and the second transducer component is provided as a second ring-shaped structure.

[0010] According to one example, the first transducer component and the second transducer component are disposed adjacent to one another.

[0011] According to one example, the processor is configured to drive at least one first transducer component and at least one second transducer component of the transducer arrangement with an oscillating AC current as an operating voltage and a reverse bias DC voltage to achieve a phase shift, preferably the phase shift resulting in an interference effect.

[0012] According to the present invention, there is provided a flow measurement device. The device comprises a sensor according to one of the previous examples. The device also comprises an operating structure for manipulating and positioning the transducer array. The operating structure has a distal end and a proximal end. The transducer is attached to the distal end of the operating structure. Furthermore, a data connection is provided to the proximal portion, the data connection configured to provide measured flow data.

[0013] According to the present invention, an ultrasound imaging system for flow measurement is provided. Optionally, the system comprises a sensor for flow measurement according to one of the previous examples. In another option, additionally or alternatively, the system comprises a flow measurement device according to one of the previous examples. Further, an operating console is provided. The operating console is configured to operate at least one first transducer component and at least one second transducer component of the transducer arrangement of the sensor.

[0014] According to the present invention, there is also provided a drive circuit for operating a sensor for flow measurement. The drive circuit has a primary high voltage input for supplying an AC current to at least one first ultrasonic transducer element and at least one second ultrasonic transducer element, both of which function as ultrasonic transmitters. The drive circuit also has secondary inputs for a first bias DC voltage and a second bias DC voltage. The drive circuit further has a common-line connection interface having a common connection to the at least one first ultrasonic transducer element and the at least one second ultrasonic transducer element. The drive circuit further has a dual-line connection interface having a first connection for connecting with the at least one first ultrasonic transducer element and a second connection for connecting with the at least one second ultrasonic transducer element. The drive circuit has a signal output for providing a signal generated by at least one first ultrasonic transducer element and at least one second ultrasonic transducer element, both of which function as ultrasonic receivers. The primary high voltage input is switchably connectable to the at least one first ultrasonic transducer element and at least one second ultrasonic transducer element. The at least one first ultrasonic transducer element and at least one second ultrasonic transducer element are switchably connectable to the signal output. A first bias voltage is provided to the first connection and a second bias voltage is provided to the second connection such that at least a phase shift is provided between the at least one first ultrasonic transducer element and the at least one second ultrasonic transducer element.

[0015] According to one example, the primary high voltage input has a first high voltage input for supplying at least one first ultrasonic transducer element via a first connection and a second high voltage input for supplying at least one second ultrasonic transducer element via a second connection. Furthermore, at least one of the first bias voltage and the second bias voltage is adjustable to adapt a degree of phase shift between the at least one first ultrasonic transducer element and the at least one second ultrasonic transducer element.

[0016] According to one example, the primary high voltage input is connectable to at least one first ultrasonic transducer element and at least one second ultrasonic transducer element via a common line. Further, the first and second bias voltages are provided as opposite bias voltages.

[0017] According to the present invention, a method for flow measurement is provided, the method comprising the steps of: supplying, in a first mode, an AC power supply current to at least one first transducer component and at least one second transducer component of a transducer arrangement, the at least one first transducer component and the at least one second transducer component being arranged to have at least partially a common field of view during operation; and operating the at least one first transducer component and the at least one second transducer component with a phase shift by supplying a first bias DC voltage to the at least one first transducer component and a second bias DC voltage to the at least one second transducer component.

[0018] Further provided is the step of receiving signals from the at least one first transducer component and the at least one second transducer component alternately in the second mode.

[0019] According to one aspect, a flow measurement sensor is provided having first and second transducer portions operated in phase shift to provide an expanded viewing angle, hi one example, a double donut (or double donut) structure is provided.

[0020] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0021] Exemplary embodiments of the invention are described below with reference to the following drawings: [Brief description of the drawings]

[0022] [Figure 1] 1 shows a schematic diagram of an example of a sensor for measuring flow. [Diagram 2] A further example of a sensor having a double donut (or donut) structure is shown. [Diagram 3] 1 shows a cross section through a sensor having a double donut structure. [Figure 4] 1 illustrates a schematic diagram of an example of a flow measurement device. [Diagram 5] 1 shows an intravascular flow measurement device. [Figure 6] 1 illustrates an example of an ultrasound imaging system for flow measurement. [Figure 7] 1 shows the capture angle of a standard donut-shaped membrane. [Figure 8] 1 shows the capture angle of a double donut shaped membrane. [Figure 9] A first example of a drive circuit for operating two donuts in anti-phase (180° phase delay) or with a selectable phase delay between 0° and 180° is shown. [Figure 10] A second example of a drive circuit is shown which operates two donuts in anti-phase (180° phase delay) by operating the two donuts with opposite bias voltage polarity. [Figure 11] 1 illustrates the basic steps of an example method for flow measurement. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Certain embodiments will now be described in detail with reference to the accompanying drawings. In the following description, like drawing reference numbers are used for like elements in different drawings. Matters defined herein, such as detailed configurations and elements, are provided to aid in a comprehensive understanding of the exemplary embodiments. Also, well-known functions or configurations will not be described in detail since they would obscure the embodiments in unnecessary detail. Furthermore, phrases such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify individual elements of the list.

[0024] 1 shows a schematic diagram of an example of a sensor 10 for flow measurement. The sensor 10 has a transducer arrangement 12 having at least one first transducer component 14 and at least one second transducer component 16. The at least one first transducer component 14 and the at least one second transducer component 16 are configured to have at least a partially common field of view during operation. The at least one first transducer component 14 and the at least one second transducer component 16 are configured to be operated with a phase shift.

[0025] The term "transducer component" refers to a transducer element capable of transmitting and receiving ultrasonic waves.

[0026] In one example, the second transducer component is disposed annularly relative to the first transducer component. Optionally, the first transducer component 14 and the second transducer component 16 are disposed concentrically. The term "concentric" refers, for example, to a configuration having overlapping geometric centers.

[0027] Optionally, the first transducer component 14 is provided as a first ring-shaped structure and the second transducer component 16 is provided as a second ring-shaped structure. The term "ring-shaped" relates to circular ring shapes, but also to elliptical, square, rectangular and polygonal ring shapes.

[0028] 2 shows a further example of a sensor 10 having a double donut structure. As an example, the first and second ring-shaped structures are provided as a double donut shaped structure, where with respect to the first ring-shaped structure, e.g., the first donut 22, the second ring-shaped structure, e.g., the second donut 24, has a larger outer diameter that surrounds a central portion 26. The first donut may also surround a central portion 28.

[0029] In one embodiment, the first and second ring-shaped structures, the first and second transducer components, respectively, are made from conventional piezoelectric transducers, and the central portion 28 and / or annular space 26 separating the first transducer component from the second transducer component have through holes for connecting the top or distal electrodes of the respective first and second ultrasonic transducer components with electrical wires that extend through the elongated body of the flow measurement device 104 and connect the distal electrodes to the driving and readout electronics of the operating console 162. In one embodiment, the first transducer component is disk-shaped without the central portion 28, and has only the annular space 26 with a trough hole separating the first transducer component from the second transducer component. The bottom proximal electrodes of the first and second transducer components are connected to electrical wires that extend from the proximal portion of the elongated body to the proximal or bottom electrodes of the first and second transducer components. The connection of the transducer component of the measurement device to the console can be achieved via a wired connection 172 or via a wireless connection, in the latter case a wireless emitter / receiver is located in the proximal portion of the measurement device and communicates wirelessly with a wireless emitter / receiver located in the operating console. In an alternative embodiment, the electrical connections are embedded within the core wires and individually insulated to form the elongated body of the measurement device.

[0030] In an alternative embodiment, the double donut or the first and second ring-shaped structures can be manufactured using semiconductor technology, for example CMOS. The transducer components can be piezoelectric micromachined ultrasonic transducers, PMUTs, or capacitive micromachined ultrasonic transducers, CMUTs, exemplarily shown in FIG. 3. In cross section, the first donut 22 is arranged in a central part surrounded on both sides by parts of the second donut 24. The first donut 22, i.e. the first transducer, is provided with a first ring-shaped cavity 30 and with an upper electrode 32 and a lower electrode 34. The second donut 24, i.e. the second transducer, is provided with a second ring-shaped cavity 36, with an upper electrode 38 and with a lower electrode 40.

[0031] 2 and 3, the two donuts can be operated in anti-phase, i.e., with a phase delay of 180°, to achieve a very large acceptance angle of more than 60°. In addition, the acceptance angle can be adjusted by selecting a phase delay between 0° and 180°.

[0032] Additionally, implementation of the double donut concept in CMUT technology solves or reduces problems associated with low SNR, low bandwidth, reliability and performance issues, and resonant frequency drift and variability.

[0033] As an example, an inner donut is provided having an outer diameter of 270 microns and an inner diameter of 35 microns. The outer donut is larger, having a diameter of, for example, 355 microns. An operating frequency of 12 MHz is provided.

[0034] An advantage of a transducer provided as a CMUT is that, in contrast to a transducer provided as a lead zirconate titanate (PZT) transducer, no frequency tuning is required.

[0035] In an option not shown in detail, the first transducer component 14 and the second transducer component 16 are provided adjacent to one another. The term "adjacent to one another" refers to a side-by-side, i.e. adjacent or neighboring, arrangement.

[0036] In another option, not shown in detail, the transducer arrangement 12 comprises a transducer array having a plurality of first and second ring-shaped structures.

[0037] In another option, not shown in detail, the transducer arrangement 12 comprises a transducer array having a plurality of first and second transducer components 14, 16 disposed adjacent to one another. The term "array" refers to a plurality of transducer elements.

[0038] 1, a processor 18 is also provided that is configured to drive and read out the transducer arrangement 12, preferably at an operating frequency of 12 MHz. The processor 18 provides a phase shift for the operation of the at least one first transducer component 14 and the at least one second transducer component 16 of the transducer arrangement 12. For example, the processor 18 is provided as an ASIC (Application Specific Integrated Circuit).

[0039] In one example, the processor 18 is configured to drive at least one first transducer component 14 and at least one second transducer component 16 of the transducer arrangement 12 with an oscillating AC current as an operating voltage and a reverse bias DC voltage to achieve a phase shift.

[0040] Optionally, a phase shift provides an interference effect.

[0041] 4 shows a schematic diagram of an example of a flow measurement device 50. The flow measurement device 50 comprises an example of a sensor 10 according to one of the examples described above. Further, a motion structure 52 for manipulating and positioning the transducer array is provided. The motion structure 52 has a distal end 54 and a proximal end 56. The transducers are attached to the distal end 54 of the motion structure 52. A data connection 58 is provided at a proximal portion or end 56, the data connection 58 being configured to provide measured flow data.

[0042] The term "actuation structure" refers to a physical structure that allows for manipulation, such as manual manipulation by a user. Actuation structure 52 can be a housing having a portion that acts as a grip or handle portion. Actuation structure 52 can be an elongated structure for insertion into a luminal structure of a subject.

[0043] The term "distal end" refers to the end of the structure that faces away from the user when the sensor is operated, i.e., the end that is further from the user and closer to the object being inspected or observed. The term "proximal end" refers to the end of the structure that faces towards the user when the sensor is operated, i.e., the end that is closer to the user.

[0044] For example, in the case of a double donut configuration, the polarity of the outer ring is reversed with respect to the inner ring by adding a 180° delay to the outer ring transmitter.

[0045] An option is also provided to adjust the take-off angle by selecting any delay between 0° and 180°.

[0046] Optionally, the operating structure 52 is an elongate structure configured for insertion at least at a distal end into a lumen for in vivo vascular flow measurement. For example, an intravascular device is provided. The term "in vivo" relates to flow measurement inside a body structure, for example, inside the lumen of a blood vessel or organ.

[0047] FIG. 5 shows a schematic cross-section of a blood vessel 102 with a flow measurement device 104. The blood vessel 102 is indicated by a blood vessel wall 106. Blood flow within the blood vessel is indicated by blood cells 108 moving along the blood vessel in a blood flow direction 110. The blood flow measurement device, for example an ultrasound device 104, has a transducer 112 at its distal end. The transducer 112 emits ultrasound waves 114 and receives reflected waves 116, resulting in ultrasound measurement data that is transferred to a processor (not shown). FIG. 5 also shows an example of a transducer field of view 120 with a resulting sample volume 122 in which blood flow is detected, i.e. measured.

[0048] In one example, the flow measurement device is a flow measurement wire.

[0049] In another example, the flow measurement device is an intravascular device.

[0050] In another example, the flow measurement device is an intraluminal device.

[0051] In another example, the flow measurement device is a guidewire having a flow measurement sensor.

[0052] The distal end includes a flow sensor and is configured for insertion into a lumen, such as a hollow organ or blood vessel, within a region of interest of a subject's body structure.

[0053] Specifically shown, and in another option, the operative structure is an ultrasound probe configured for extracorporeal positioning for external measurement of flow within a body cavity, the term "extracorporeal" referring to placement of the sensor outside the body structure.

[0054] FIG. 6 shows an example of an ultrasound imaging system 150 for flow measurement. The system 150 comprises an example of an apparatus for flow measurement according to one of the examples described above and below. Further, an interventional device 152 is provided having an ultrasound transducer 154 attached to a distal portion of the interventional device 152. The interventional device 152 is at least data-connected to the apparatus 10 for flow measurement. The ultrasound transducer 154 generates a plurality of ultrasound signals that are provided to a data input (not shown in detail). Optionally, FIG. 6 shows a subject support 156, e.g., a patient table.

[0055] The device for flow measurement may be provided as a movable control or operating console 162, which may comprise a graphical user interface 158, such as a display and / or an audio user interface and further control elements. Furthermore, a monitoring device 160 is provided in the vicinity of the patient support 156, such as a ceiling or wall mounted display. As a further option, an additional imaging system is provided, such as an X-ray imaging system 164 having an X-ray source 166 and an X-ray detector 168 mounted on a movably supported C-arm structure. An object of interest, such as a subject 170, may be placed on the subject support 156. The subject 170 is shown with a cover drape. The line 172 indicates a data connection, which may be wired and / or wireless.

[0056] The operating console 162 is configured to operate at least one first transducer component and at least one second transducer component of the transducer arrangement of the sensor. The term "operating console" refers to an interface provided for a user to control the operation of the sensor.

[0057] 7 shows the capture angle 200 of a standard donut-shaped membrane, indicated by a first pair of arrows 202. The vertical axis 204 shows, for example, normalized pressure, and the horizontal axis 206 shows angle. A single donut 208 is shown as a reference. A first curve 210 shows the theoretically determined directivity function. A second curve 212 shows the simulated directivity function.

[0058] 8 shows the capture angle 214 of a double donut shaped membrane, indicated by a second pair of arrows 216. The vertical axis 218 shows, for example, normalized pressure, and the horizontal axis 220 shows angle. A double donut 222 is shown as a reference. A third curve 224 shows a theoretically determined directivity function for the double donut structure. A fourth curve 226 shows a simulated directivity function for the double donut structure.

[0059] As can be seen, the take-up angle of the double donut shape is significantly larger than that of the single donut shape: for example, for a pressure index of about 0.7 norm, the take-up angle of the single donut structure is 27°, while for the same pressure index of about 0.7 norm, the take-up angle of the double donut structure is 50°-70°, e.g. 64°, with a phase delay of 180° in operation.

[0060] Thus, in one example, a double donut shaped CMUT membrane is provided, see also Figures 2 and 3. By adding an outer ring (donut) to a standard donut shaped CMUT membrane and operating the outer ring in anti-phase with the inner donut, a large acceptance angle can be achieved (see Figures 7 and 8).

[0061] Further, as shown in Fig. 9 and Fig. 10, driver circuits 250a and 250b are provided for operating the sensor for flow measurement. Referring to Fig. 9, the driver circuit 250a has a primary high voltage input 252a for supplying alternating current to at least one first ultrasonic transducer element 254a and at least one second ultrasonic transducer element 256a, both of which function as ultrasonic transmitters. As an example, the at least one first ultrasonic transducer element 254a is provided as an inner ring of a double donut structure, and the at least one second ultrasonic transducer element 256a is provided as an outer ring of the double donut structure. The driver circuit 250a has a secondary input 258a for a first bias DC voltage 260a and a second bias DC voltage 262a. The driver circuit 250a also has a common line 264a connection interface with a common connection to at least one first ultrasonic transducer element 254a and at least one second ultrasonic transducer element 256a. The driver circuit 250a has a dual line connection interface 266a with a first connection 268a for connecting with at least one first ultrasonic transducer element 254a and a second connection 270a for connecting with at least one second ultrasonic transducer element 256a. The driver circuit 250a has a signal output 272a for providing signals generated by at least one first ultrasonic transducer element 254a and at least one second ultrasonic transducer element 256, both of which function as ultrasonic receivers.

[0062] Optionally, the signal output 272a is split and the two output signals are processed separately.

[0063] The primary high voltage input 252a is switchably connectable to at least one first ultrasonic transducer element 254a and at least one second ultrasonic transducer element 256a. The at least one first ultrasonic transducer element 254a and at least one second ultrasonic transducer element 256a are switchably connectable to a signal output 272a. A first bias voltage 260a is provided to the first connection 268a, and a second bias voltage 262a is provided to the second connection 270a such that at least a phase shift is provided between the at least one first ultrasonic transducer element 254a and the at least one second ultrasonic transducer element 256a.

[0064] Thus, for example, a circuit is provided which drives two transducer elements in anti-phase.

[0065] The term "common line" 264a refers to a single connection that feeds both transducer elements. The term "dual line" 266a refers to two separate connections.

[0066] The first frame 274a shows the structure of the housing of the driver circuit 250a. The second frame 276a shows the structure of the sensor arrangement, e.g., the structure of a flow measurement device, such as an intravascular device. The driver circuit 250a can be arranged separately from the structure of the sensor arrangement. In another option, the driver circuit 250a is arranged integrally with the structure of the sensor arrangement.

[0067] The above mentioned features are indicated with reference numerals having index "a" for the options shown in the example of Figure 9, while similar features apply with respective index "b" for the options shown in the example of Figure 10. Further details, in particular the different features of Figures 9 and 10, are also explained below.

[0068] Optionally, a driver circuit 250a (250b) is provided to operate the sensor for flow measurement according to one of the previous examples.

[0069] In another option, a driver circuit 250a (250b) is provided to operate a sensor in a flow measurement device according to one of the previous examples.

[0070] In a further option, the driver circuit 250a (250b) is provided to operate a sensor in an ultrasound imaging system for flow measurement according to one of the previous examples.

[0071] In one example, the first ultrasonic transducer element 254a (254b) is provided as a first piezoelectric element, for example, a capacitive micromachined ultrasonic transducer (CMUT) element. In one example, the second ultrasonic transducer element 256a (256b) is provided as a second piezoelectric element, for example, a CMUT element.

[0072] An example is provided based on a CMUT ultrasonic transducer using a double donut concept, which allows for a large acceptance angle, while the CMUT-based ultrasonic transducer allows for a large bandwidth and reduced resonant frequency variability.

[0073] The driving circuit 250a in Fig. 9 is proposed to drive two donuts, for example. The two high voltage transmit (HV TX) signals can be selected to have a phase delay of 180° to obtain the maximum capture angle. It should be noted that the capture angle can be adjusted by selecting a phase delay between 0° and 180°.

[0074] FIG. 9 shows a first example of a drive circuit 250a for operating two donuts in anti-phase (180° phase delay) or with a selectable phase delay between 0° and 180°.

[0075] 9, the primary high voltage input 252a has a first high voltage input 278a for supplying at least one first ultrasonic transducer element 254a via a first connection 268a and a second high voltage input 280a for supplying at least one second ultrasonic transducer element 256a via a second connection 270a. At least one of the first bias voltage 260a and the second bias voltage 262a is adjustable to adapt the degree of phase shift between the at least one first ultrasonic transducer element 254a and the at least one second ultrasonic transducer element 256a.

[0076] 9, the signal output 272a has a first signal output 282a for providing a signal generated by at least one first ultrasonic transducer element 254a. The signal output 272a also has a second signal output 284a for providing a signal generated by at least one second ultrasonic transducer element 256a.

[0077] The first high voltage input 278a is switchably connected to the first connection 268a via a first switch 286a. The second high voltage input 280a is switchably connected to the second connection 270a via a second switch 288a.

[0078] The first connection 268a is switchably connected to the first signal output 282a via a third switch 290a. The second connection 270a is switchably connected to the second signal output 284a via a fourth switch 292a.

[0079] A capacitor configuration may be provided in the dual line connection interface 266a having a first capacitor 294a in the first connection 268a and a second capacitor 296a in the second connection 270a.

[0080] The common line 264a in the example of FIG. 9 is connected to ground.

[0081] In one example, it is provided to invert the polarity of the outer ring with respect to the inner ring by reversing the bias voltage. With this concept, two acceptance angles can be selected, i.e., a narrow beam by selecting equal bias voltages, or a wide beam by selecting opposite bias voltages. In one example, the resonant frequency and bandwidth can be optimized for reception and transmission by selecting individual optimal bias voltage levels for the inner and outer rings in the case of a double donut structure. As an example, the bias voltage of one of the transducers can be selected to be, for example, 0V to "switch" off the inner or outer element (or both).

[0082] Alternatively, the circuit of FIG. 10 is proposed to operate the two donuts, for example in anti-phase. This is achieved by operating the two donuts with opposite bias voltage polarities. It is noted that in this configuration, a small or large acceptance angle can be selected, i.e. by setting equal or opposite bias voltage polarities, respectively. It is also noted that in this configuration, it is possible to slightly tune and match the resonant frequencies of the two donuts by adapting the individual bias voltage levels.

[0083] FIG. 10 shows a second example of a drive circuit 250b that operates the two donuts in anti-phase (180° phase delay) by operating the two donuts with opposite bias voltage polarities.

[0084] 10, the primary high voltage 252b input can be connected to at least one first ultrasonic transducer element 254b and at least one second ultrasonic transducer element 256b via a common line 264b. The first and second bias voltages 260b, 262b are provided as opposite bias voltages.

[0085] The high voltage input 252b is switchably connected to a common line 264b via a first further switch 298b, which is switchably connected to a signal output 272b via a second further switch 297b.

[0086] A capacitor arrangement may be provided in the dual line connection interface 266b having a first further capacitor 295b in the first connection 268b and a second further capacitor 293b in the second connection 270b.

[0087] The first connection 268b and the second connection 270b of the dual line connection interface 266b of FIG. 10 are connected to ground.

[0088] 11 shows the basic steps of an example of a method 300 for flow measurement. The method includes the following steps:

[0089] In a first mode, a step 302 of supplying an AC power supply current to at least one first transducer component and at least one second transducer component of a transducer arrangement is provided. The at least one first transducer component and the at least one second transducer component are arranged to have at least a partially common field of view during operation. Furthermore, a step 304 of operating the at least one first transducer component and the at least one second transducer component with a phase shift is provided by supplying a first bias DC voltage to the at least one first transducer component and a second bias DC voltage to the at least one second transducer component. The two actions, i.e. supplying 302 by the power supply and operating 304, are provided more or less simultaneously.

[0090] A step 306 of receiving signals from at least one first transducer component and at least one second transducer component alternately in a second mode is provided.

[0091] The looped arrow 308 indicates the option of continuous alternating operation in the first and second modes.

[0092] A first mode, also called an ultrasonic transmission mode, is illustrated by a first frame 310. A second mode, also called an ultrasonic reception mode, is illustrated by a second frame 312.

[0093] In one example, a computer program is provided that enables a processor to carry out the method of the previous examples.

[0094] In one example, a computer program or program element for controlling an apparatus according to one of the above examples is provided, which program or program element is configured to perform the method steps of one of the above method examples when executed by a processing unit.

[0095] In another example, a computer readable medium having stored thereon the program elements of the previous examples is provided.

[0096] The term "subject" may also be referred to as an individual. A "subject" may also be referred to as a patient, although it should be noted that this term does not indicate whether any disease or illness is actually present in the subject.

[0097] In another exemplary embodiment of the invention, a computer program or a computer program element is provided, characterized in that it is arranged for, on a suitable system, to carry out the method steps of the method according to one of the previous embodiments.

[0098] Thus, the computer program element may be stored in a computing unit or distributed across two or more computing units that may be part of an embodiment of the present invention. This computing unit may be configured to execute or direct the execution of the steps of the above-mentioned method. Furthermore, it may be configured to operate the components of the above-mentioned apparatus. The computing unit may be configured to operate automatically and / or to execute a user's order. The computer program may be loaded into a working memory of a data processor. The data processor may thus be equipped to execute the method of the present invention.

[0099] Aspects of the invention may be embodied in a computer program product, which may be a collection of computer program instructions stored on a computer-readable storage device that may be executed by a computer. The instructions of the invention may be any interpretable or executable code mechanism, including, but not limited to, a script, an interpretable program, a dynamic link library (DLL), or a Java class. The instructions may be provided as a complete executable program, a partial executable program, a modification (e.g., an update) to an existing program, or an extension (e.g., a plug-in) to an existing program. Additionally, parts of the processing of the invention may be distributed across multiple computers or processors.

[0100] As mentioned above, a processing unit, e.g., a controller, implements the control method. This controller can be implemented in various ways using software and / or hardware to perform the various functions required. The processor is one example of a controller that uses one or more microprocessors that can be programmed using software (e.g., microcode) to perform the required functions. However, the controller may be implemented with or without a processor, or as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions.

[0101] Examples of controller components that may be used in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASICs), and field programmable gate arrays (FPGAs).

[0102] This exemplary embodiment of the invention encompasses both computer programs that use the invention from the outset, and computer programs that convert existing programs by means of updates into programs that use the invention.

[0103] Moreover, the computer program element may be capable of providing all the steps required to fulfill the procedures of the exemplary embodiments of the methods described above.

[0104] According to a further exemplary embodiment of the present invention, a computer readable medium, such as a CD-ROM, is presented, having stored thereon a computer program element, which is described by the previous section. The computer program may be stored and / or distributed on a suitable medium, such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless communication systems.

[0105] However, the computer program may also be presented over a network such as the World Wide Web and can be downloaded from such a network into the working memory of a data processor. According to a further exemplary embodiment of the invention, a medium for making a computer program element downloadable is provided, this computer program element being configured to perform a method according to one of the aforementioned embodiments of the invention.

[0106] It should be noted that the embodiments of the present invention are described with reference to different subject matters. In particular, some embodiments are described with reference to method type claims, and other embodiments are described with reference to device type claims. However, those skilled in the art will understand from the above and the following description that, unless otherwise notified, any combination of features belonging to one type of subject matter, as well as any combination between features relating to different subject matters, is considered to be disclosed in this application. However, all features can be combined to provide a synergistic effect that is higher than the simple sum of the features.

[0107] While the invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description are to be considered as illustrative or exemplary and not restrictive. The invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the dependent claims.

[0108] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope.

Claims

1. A transducer configuration having at least one first transducer component and at least one second transducer component, In a sensor for flow measurement having, The at least one first transducer component and the at least one second transducer component are arranged to have at least partially common fields of view during operation. The at least one first transducer component and the at least one second transducer component are configured to operate with a phase shift. Sensor.

2. The sensor according to claim 1, wherein the second transducer component is provided in a ring shape on the first transducer component.

3. The sensor according to claim 1 or 2, wherein the first transducer component and the second transducer component are arranged concentrically.

4. The sensor according to claim 1, wherein the first transducer component is provided as a first ring-shaped structure, and the second transducer component is provided as a second ring-shaped structure.

5. The sensor according to claim 1, wherein the first transducer component and the second transducer component are provided adjacent to each other.

6. The transducer configuration described above is: i) Multiple first and second ring-shaped structures, or ii) A plurality of first and second transducer components provided adjacent to each other, Having a transducer array having The sensor according to claim 1.

7. A processor configured to drive and / or read the transducer configuration is further provided, The processor is configured to provide a phase shift for the operation of the at least one first transducer component and the at least one second transducer component of the transducer configuration. The sensor according to claim 1.

8. The sensor according to claim 7, wherein the processor is configured to drive the at least one first transducer component and the at least one second transducer component of the transducer configuration with an oscillating AC current as an operating voltage and a reverse bias DC voltage to achieve the phase shift.

9. A sensor according to any one of claims 1 to 8, An operating structure for operating and positioning the transducer configuration, In a flow measuring device having, The transducer configuration is attached to the distal end of the operating structure. A data connection is provided in the proximal portion of the operating structure, and the data connection is configured to provide measured flow data. Flow measurement device.

10. The aforementioned operating structure is, An elongated structure configured such that at least the distal end is inserted into a lumen for measuring blood flow within the body, An ultrasonic probe configured for external positioning for external measurement of intra-body fluid flow, The apparatus according to claim 9, which is one of them.

11. The flow measuring device according to claim 9, Operating console and In an ultrasonic system for flow measurement having, The operating console is configured to operate the at least one first transducer component and the at least one second transducer component of the transducer configuration of the sensor. Ultrasonic system.

12. A drive circuit for operating a sensor according to any one of claims 1 to 8 for flow measurement, wherein the drive circuit comprises: In transmission mode, a primary high-voltage input section is configured to supply alternating current to at least one first ultrasonic transducer component and at least one second ultrasonic transducer component, A secondary input section for the first bias DC voltage and the second bias DC voltage, A common line connection interface having a common connection to at least one first ultrasonic transducer component and at least one second ultrasonic transducer component, A first connection for connection to at least one first ultrasonic transducer component, and A second connection portion for connecting to at least one second ultrasonic transducer component, A dual-line connection interface having, In receiving mode, a signal output unit for providing signals generated by the at least one first ultrasonic transducer component and the at least one second ultrasonic transducer component, It has, The primary high-voltage input section is switchably connectable to at least one first ultrasonic transducer component and at least one second ultrasonic transducer component. The at least one first ultrasonic transducer component and the at least one second ultrasonic transducer component are switchably connectable to the signal output unit. The first bias voltage is supplied to the first connection, and the second bias voltage is supplied to the second connection such that at least a phase shift is provided between the at least one first ultrasonic transducer component and the at least one second ultrasonic transducer component. Drive circuit.

13. The primary high-voltage input section includes a first high-voltage input section for supplying to the at least one first ultrasonic transducer component via the first connection section, and a second high-voltage input section for supplying to the at least one second ultrasonic transducer component via the second connection section. At least one of the first bias voltage and the second bias voltage is adjustable to adapt the degree of phase shift between the at least one first ultrasonic transducer component and the at least one second ultrasonic transducer component. The drive circuit according to claim 12.

14. The primary high-voltage input section is connectable to the at least one first ultrasonic transducer component and the at least one second ultrasonic transducer component via the common line. The first and second bias voltages described above are provided as opposite bias voltages. The drive circuit according to claim 12.

15. A method for measuring flow, In the first mode, A step of supplying AC power current to at least one first transducer component and at least one second transducer component of a transducer configuration, wherein the at least one first transducer component and the at least one second transducer component are arranged to have at least partially common fields of view during operation; The steps of supplying a first bias DC voltage to the at least one first transducer component and a second bias DC voltage to the at least one second transducer component, thereby causing the at least one first transducer component and the at least one second transducer component to operate in a phase shift; In the second mode, alternately, The steps include receiving signals from the at least one first transducer component and the at least one second transducer component, A method of having.

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