Device for performing ultrasonic examinations and pressure measurements

Abstract

A device (1) for performing ultrasonic examinations and pressure measurements comprises an ultrasonic transducer (60), a pressure sensor (50), a housing (10) to accommodate the ultrasonic transducer (60) and the pressure sensor (50), a support plate (40) arranged in the housing (10) and a flexible membrane (21) arranged on the end face of the housing. A sealed chamber (47) for receiving a liquid medium is formed between the membrane (21) and the support plate (40), and the ultrasonic transducer (60) and the pressure sensor (50) are arranged on the support plate (40) in such a way that a first transmission surface of the ultrasonic transducer (60) and a second transmission surface of the pressure sensor (50) are directed towards the chamber (47).

Claims

1-14. (canceled)

15. A device for performing ultrasonic examinations and pressure measurements, comprising: an ultrasonic transducer; a pressure sensor; a housing to accommodate the ultrasonic transducer and the pressure sensor; a support plate arranged in the housing; and a flexible membrane arranged at the front of the housing; wherein a sealed chamber for receiving a liquid medium is formed between the flexible membrane and the support plate, and wherein the ultrasonic transducer and the pressure sensor are arranged on the support plate in such a way that a first transmission surface of the ultrasonic transducer and a second transmission surface of the pressure sensor are directed towards the sealed chamber.

16. The device according to claim 15, wherein the flexible membrane has a circular base.

17. The device according to claim 15, wherein a retaining ring cooperates with a peripheral retaining region of the support plate and encloses a proximal retaining section of the flexible membrane and holds it on the support plate.

18. The device according to claim 17, wherein the flexible membrane has a bead in the holding section, which cooperates with a circumferential groove of the support plate, which is arranged distally in front of the holding area.

19. The device according to claim 17, wherein a proximal section of the retaining ring interacts with a shell-side region of the housing.

20. The device according to claim 19, wherein, in the assembled state, a circumferential seal is arranged between the proximal section of the retaining ring and the shell-side region of the housing.

21. The device according to claim 15, wherein the ultrasonic transducer is attached centrally to the support plate and wherein the pressure sensor is attached eccentrically to the support plate.

22. The device according to claim 15, wherein the ultrasonic transducer and the pressure sensor are each accommodated in a through-opening of the support plate, the through-openings with accommodated ultrasonic transducer and pressure sensor being sealed against passage of the liquid medium.

23. The device according to claim 15, wherein the chamber is filled with an ultrasound-transparent liquid.

24. The device according to claim 23, wherein the ultrasonically transparent liquid is an oil with a viscosity in a viscosity class of 32-68 ISO VG.

25. The device according to claim 15, comprising a filling opening for the liquid medium, which is designed as a through-opening in the support plate.

26. The device according to claim 15, wherein a circuit board for holding electronic components is fixed to a rear surface of the support plate, and a main surface of the circuit board extends substantially perpendicular to a main surface of the support plate.

27. A method of assembling a device for performing ultrasonic examinations and pressure measurements, comprising: an ultrasonic transducer; a pressure sensor; a housing to accommodate the ultrasonic transducer and the pressure sensor; a support plate arranged in the housing; and a flexible membrane arranged at the front of the housing; wherein a sealed chamber for receiving a liquid medium is formed between the flexible membrane and the support plate, and wherein the ultrasonic transducer and the pressure sensor are arranged on the support plate in such a way that a first transmission surface of the ultrasonic transducer and a second transmission surface of the pressure sensor are directed towards the sealed chamber, the method comprising: inserting, sealing and fastening the ultrasonic transducer and the pressure sensor in the support plate; inserting a filling hose into the support plate; attaching the flexible membrane to the support plate to form the sealed chamber; filling the liquid medium into the chamber through the filling hose; and closing a filling opening for the liquid medium as soon as a predetermined quantity of the medium has been filled in.

28. The method according to claim 27, wherein a retaining ring is slid over the membrane and fastened to the support plate to form the sealed chamber after the flexible membrane has been attached.

29. The device according to claim 19, wherein the proximal section of the retaining ring interacts with the shell-side region of the housing in the manner of a clip connection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings used to illustrate the embodiment example show:

[0054] FIG. 1 An oblique view of an embodiment of a device according to the invention for carrying out ultrasonic examinations and pressure measurements;

[0055] FIG. 2 another oblique image of the device, with the housing shown transparent;

[0056] FIG. 3 another oblique view of the device with the housing only partially shown;

[0057] FIG. 4A a cut-away diagonal view of the device;

[0058] FIG. 4 Legs an enlarged section from FIG. 4A;

[0059] FIG. 5A, B a side view and a cross-sectional view of the membrane element of the device; and

[0060] FIG. 6 a top view and a bottom view of the support plate of the device.

[0061] In principle, identical parts are marked with identical reference signs in the figures.

WAYS TO CARRY OUT THE INVENTION

[0062] FIG. 1 is an oblique view of an embodiment of a device according to the invention, the measuring unit 1, for carrying out ultrasonic examinations and pressure measurements. The measuring unit 1 comprises an elongated housing 10 made of ABS plastic with a wall thickness of 2.3 mm. It comprises a main part 10a, which has an essentially rectangular cross-section with rounded corners transverse to the longitudinal axis and is designed in this section so that a user can easily grasp and hold it with one hand. In a rear part 10b, the cross-section of the housing 10 tapers down to an end wall 10c of the housing 10 (see also FIG. 2). An opening is recessed in this end wall 10c, through which a cable 15 runs, protected by a strain relief 16. In a front part 10d, the housing shape merges into a connection ring 10e. To this, a membrane element 20 with a membrane 21 is attached to the front of the housing 10 via a retaining ring 30, as described in detail below.

[0063] As can be seen in FIG. 2, in which the housing 10 is shown transparently, a first printed circuit board 71 (mainboard) and a second printed circuit board 72 (piggyback) are accommodated in the housing 10. The first printed circuit board 71 extends essentially over the entire length of the housing 10, while the second printed circuit board 72 only requires part of the housing length.

[0064] FIG. 3 is another oblique view of the device with the housing only partially shown. FIG. 4 shows a cut-away oblique view of the device. A support plate 40 made of anodized aluminum is arranged in the front area of the housing 10, the main surface of which runs transversely to the longitudinal axis of the measuring unit 1. The support plate 40 is shown in FIGS. 6A, 6B. It is circular and comprises a base plate 41 and a jacket 42, on which an external thread 43 is formed. A rectangular opening 44 with rounded corners is arranged in the base plate 41. It extends diametrically over essentially the entire diameter up to a circumferential edge section. A further opening in the base plate 41 opens into a cylindrical receptacle 45, which has a support flange 45a flush with the end face. A further opening in the end face of the base plate 41 opens into a channel 46. The support plate 40 accommodates a pressure sensor 50 in the receptacle 45 and an ultrasonic transducer 60 with a piezo array in the opening 44.

[0065] The pressure sensor 50 comprises a piezoresistive measuring element that is accommodated in a cylindrical steel housing. The front of the pressure sensor 50 comprises a stainless steel membrane. The pressure acting on it is further transmitted to the measuring element. The pressure sensor 50 has a measuring range of 0-0.35 bar. It provides an amplified analog output signal that can be processed immediately.

[0066] A holder 73 for the first printed circuit board 71 is arranged on the rear side of the support plate 71. The pressure sensor 50 is connected to the first printed circuit board 71 via a connection cable 52, which is designed as a flat cable. The ultrasonic transducer 60 is also connected to the first printed circuit board 71 via a further connection cable 61, again a flat cable.

[0067] The membrane element 20 (see FIGS. 5A, 5B) is made of silicone rubber with a hardness of 40 Shore A. It is completely circularly symmetrical, has a circular base area with a diameter of approx. 50 mm and has a first, cylindrical area formed by a jacket 22. This has an inwardly projecting bead 23 at the free rear end. The actual membrane 21 is arranged in the front area. The membrane element 20 is also preformed in the area of the actual membrane 21 and, when unfilled, has the shape of a spherical cap with a radius of curvature of 100 mm. With a membrane diameter of approx. 50 mm, this results in a height of 3.1 mm. The geometry avoids excessive lens effects with regard to the transmitted ultrasonic waves and enables good handling in the required angle range.

[0068] In the area of the membrane 21, the material thickness is 0.5 mm. In the area of the jacket 22, it is 0.8 mm. Overall, the bead has an essentially circular cross-section with a diameter of 2.0 mm.

[0069] As can be seen in particular from FIG. 4B, the jacket 22 of the membrane element 20 interacts with a distal cylindrical region of the support plate 40 in the assembled state. Proximally of this cylindrical region, the support plate 40 has a circumferential recess in which the bead 23 of the membrane element 20 is accommodated. The membrane 21 is supported in the transition area to the jacket 22 by a rounded transition surface of the support plate 40.

[0070] The membrane element 20 is secured to the support plate 40 using the stainless steel retaining ring 30. This has an internal thread 31 which interacts with the external thread 43 on the support plate 40. Both proximally and distally of the internal thread 31, the retaining ring 30 has essentially cylindrical sections. The distal section covers the jacket 22 of the membrane element 20 and thus prevents removal of the membrane element 20 due to the interaction of the bead 23 with the recess in the support plate 40. In the section proximal to the internal thread 31, the retaining ring 30 has, on the one hand, an inwardly projecting flange which interacts with an end face of the housing 10. Proximal to the flange, the retaining ring 30 embraces the casing of the housing 10. In this section, proximal to the flange, a circumferential lug 32 is formed on the retaining ring 30, which interacts with a recess 12 in the casing of the housing 10 in the manner of a clip connection. The retaining ring 30 is thus held securely on the housing 10. Furthermore, an O-ring 11 is accommodated in a groove in the outer casing of the housing 10, which, when fitted, interacts with the inside of the proximal section of the retaining ring 30 and seals the interior of the housing against the ingress of moisture and dust.

[0071] A sealed chamber 47 for receiving a liquid medium is formed between the support plate 40 and the membrane 21. On the one hand, the sealing takes place between the support plate 40 and the membrane element 20 mounted thereon. On the other hand, the pressure sensor 50 is sealed with respect to its receptacle 45 in the support plate on the one hand by a radially sealing first O-ring 53, which is arranged on the jacket of the pressure sensor 50, and on the other hand by an axially sealing second O-ring 54, which is arranged between an end-face edge section of the pressure sensor 50 and the support flange 45a of the receptacle 41.

[0072] The ultrasonic transducer 60 is sealed against the support plate 40 by means of adhesive bonding, as described in more detail below.

[0073] When mounting the measuring unit 1, the ultrasonic transducer 60 is first attached to the support plate 40. For this purpose, the transducer is inserted from the front into the corresponding opening 44, whereby the contact surfaces between the housing of the ultrasonic transducer 60 and the support plate 40 are first provided with a silicone-based adhesive. After inserting the ultrasonic transducer 60, the bonding area is shaped with a spatula to ensure a reliable seal. Finally, the bonded elements are mechanically fixed together for the drying time of the bond.

[0074] Next, a filling hose 48 made of silicone (see FIG. 3) is fed through the channel 46 in the support plate 40 and again fixed in the channel 46 on the front side with a silicone-based adhesive, whereby the end of the hose is aligned with the mouth of the channel 46 on the front side of the base plate 41. Again, the bonding also ensures the seal between the filling hose 48 and the channel 46.

[0075] Once the aforementioned bonding has dried, the membrane element 20 can be attached to the support plate 40. For this purpose, it is pulled with its jacket 22 over the jacket 42 of the support plate 40 until the bead 23 of the membrane element 20 comes to lie completely behind the recess in the jacket 42 of the support plate 40. The retaining ring 30 can then be screwed with its internal thread 31 onto the external thread 43 of the support plate 40.

[0076] To attach the pressure sensor 50, the first O-ring 54 is first inserted into the receptacle 45 of the support plate 40. It rests on the support flange 45a. The pressure sensor 50 with the second O-ring 53 is then inserted into the receptacle 45 from behind until its end face makes contact with the first O-ring 54. A holder 51 (see FIG. 3) can now be placed on the back of the pressure sensor 50 and screwed to the support plate 40 using two screws. The pressure sensor 50 is thereby pressed further forward, onto the first O-ring 54, which creates a secure seal between the pressure sensor 50 and the support plate 40.

[0077] The holder 73 for the mainboard is now attached to the ultrasonic transducer 60 and thus to the rear of the support plate 40.

[0078] Next, a clamp is pulled over the filling hose 48 and the chamber 47 is filled through the filling hose with a synthetic lubricating oil of viscosity class 46 ISO VG approved for use in the pharmaceutical sector. The weight of the partially mounted sensor including the filled liquid is monitored during filling so that filling can be stopped when a predetermined filling weight is reached. During filling, care is taken to ensure that no air bubbles remain in the chamber 47. The filling hose 48 is then closed by means of the clamp, and the free end of the filling hose 48 is placed on a mandrel, which is arranged on the rear side of the holder 51 for the pressure sensor 50.

[0079] Now the first printed circuit board 71 (mainboard) with the printed circuit board 72 (piggyback) held on it can be inserted into the holder 73, creating the connection to the ultrasonic transducer 60 at the same time. The connection cable 52 of the pressure sensor 50 is then connected with its plug to a corresponding socket on the mainboard. The connection cable 15 is also fed through the end opening in the housing 10 and connected to the mainboard with a corresponding plug. The housing 10 is finally connected to the front part (with membrane element 20, retaining ring 30, support plate 40, pressure sensor 50, ultrasonic transducer 60 and the printed circuit boards 71, 72) by pressing it into the retaining ring 30 until the clip connection engages.

[0080] The invention is not limited to the embodiment example shown. For example, the geometry of the individual components does not have to correspond to that of the embodiment. For example, the membrane can also be designed with an oval or rounded-rectangular base, which also requires adjustments to other components such as the retaining ring and the housing. The materials can also be selected differently. The chamber does not necessarily have to be sealed with the aforementioned sealing materials either.

[0081] In summary, the invention provides a device for carrying out ultrasonic examinations and pressure measurements which is simple in design and enables high image quality.