Acoustic-vibration transducer
阅读说明:本技术 声-振换能器 (Acoustic-vibration transducer ) 是由 G·博伊德 于 2018-03-26 设计创作,主要内容包括:在各种实施例中,根据本发明的声-振换能器装置被优化用于感测和转换在患者体内出现的声现象,并且以0.001Hz至10kHz的频率在皮肤表面显现它们自身。有效耦合至皮肤的策略包括正确地不匹配机械阻抗,使用阻抗匹配的凝胶或液体,设计形状的(例如圆顶的)拾音器,材料选择和/或允许内部部分和外周膜片部分之间的相对运动的外周板簧装置。可以选择性地选择板簧的弹簧刚度或弹簧柔度,以优化传感器的频率响应。(In various embodiments, acoustic-vibrating transducer devices according to the present invention are optimized for sensing and transducing acoustic phenomena occurring in a patient's body and manifest themselves on the skin surface at frequencies of 0.001Hz to 10 kHz. Strategies for effective coupling to the skin include properly mismatched mechanical impedances, use of impedance matched gels or liquids, design shaped (e.g., domed) pickups, material selection and/or peripheral leaf spring arrangements that allow relative motion between the inner portion and the peripheral diaphragm portion. The spring rate or spring compliance of the leaf spring can be selectively selected to optimize the frequency response of the sensor.)
1. A sensor apparatus, comprising:
a diaphragm having an outer peripheral portion and an inner portion connected to the outer portion by a plurality of leaf springs that limit relative movement between the movable portion and the outer peripheral portion;
a coil disposed on at least one side of the diaphragm; and
at least one magnet operatively disposed relative to the coil to cause current to flow through the coil by relative movement between the movable portion and the peripheral portion.
2. The sensor device of claim 1, wherein the inner portion is fixed and the outer peripheral portion is movable relative to the inner portion.
3. The sensor device of claim 1, wherein the outer portion is fixed and the inner portion is movable relative to the outer portion.
4. The sensor device of claim 3, wherein the outer fixed portion of the diaphragm has a shape and the inner movable portion is defined within a plurality of slits through the diaphragm and arranged in a series, wherein (i) the series defines a closed sequence concentric with the outer fixed portion and having the shape of the outer fixed portion, and (ii) each pair of slits is parallel and has an overlapping portion and a non-overlapping portion, the overlapping portion defining an inset bar corresponding to one of the leaf springs.
5. The sensor device of claim 4, wherein the slit is filled with a thixotropic material.
6. The sensor device of claim 1, wherein the coil and the at least one magnet are circular.
7. The sensor device of claim 1, wherein the at least one magnet is a pair of magnet assemblies disposed on opposite sides of the diaphragm, each of the assemblies including at least two concentric magnets.
8. The sensor device of claim 7, wherein each magnet has an isosceles trapezoidal cross-section with an angle of 45 ± 5 °.
9. The sensor apparatus of claim 1, wherein the coil occupies 50% to 75% of the diaphragm area.
10. The sensor device of claim 1, further comprising a pickup structure extending from the diaphragm to contact a biological tissue surface.
11. The sensor device of claim 10, wherein the diaphragm has a modal contribution with a zero mean volumetric velocity to isolate a pistonic response of the diaphragm to a voltage generated in a direction perpendicular to the diaphragm.
12. The sensor device of claim 1, wherein the diaphragm is a composite sandwich panel comprising a core and an integral panel on each side of the core.
13. The sensor apparatus of claim 12, wherein the panel is a copper clad flexible printed circuit polymer film.
14. The sensor apparatus of claim 13, wherein the copper is etched to ensure that 10% or less of the shortest planar dimension of the diaphragm has an isotropic mechanical resistance.
15. The sensor device of claim 12, wherein the faceplate is made of a graphene composite structure.
16. The sensor device of claim 15, wherein the graphene is etched to ensure that 10% or less of the shortest planar dimension of the diaphragm has an isotropic mechanical impedance.
17. The sensor device of claim 1, wherein the diaphragm is asymmetrically biased in a non-energized state.
18. The sensor device of claim 17, wherein the bias is in a range of 0.1mm to 3 mm.
19. The sensor apparatus of claim 8, wherein the pickup structure is a dome.
20. The sensor device of claim 16, wherein the dome has surface features.
21. The sensor device of claim 17, wherein the surface is raised, dimpled, or corrugated.
22. The sensor apparatus of claim 19, wherein the pickup structure has a mechanical impedance that is mismatched relative to a target surface.
23. An acoustic transducer, comprising:
a diaphragm including a peripheral portion and a central dome pickup portion;
a holding member surrounding the diaphragm and configured to hold the diaphragm and allow at least a part of the movement when the acoustic energy is applied to the dome sound-collecting portion; and
a transducer for converting the motion of at least a portion thereof into an electrical signal.
24. The acoustic transducer according to claim 23, wherein the transducer comprises at least one coil attached to the diaphragm and at least one magnet separate from the diaphragm but magnetically coupled to the coil.
25. The acoustic transducer of claim 23, wherein the pickup structure has a mechanical impedance that is mismatched relative to a target surface.
26. The acoustic transducer according to claim 23, wherein the diaphragm is capacitive.
Technical Field
The present invention relates generally to electro-mechanical electro-acoustic-vibratory devices, and more particularly to systems utilizing electrodynamic transducers coupled to an outer surface of biological tissue, for example, for non-invasively recording, storing, analyzing and playing back in vivo sounds produced by living organisms.
Background
The stethoscope, invented by Ren Laennec in france in 1816, is used for auscultation, i.e. listening to sounds generated in the body, mainly for the purpose of assessing the condition of organs and blood vessels, including the heart, lungs, aorta and intestines. During pregnancy, the heart sounds of the fetus may also be monitored by auscultation with a dedicated stethoscope. Blood flow in the blood vessel can also be auscultated. Auscultation without assistance with the ears is referred to as direct auscultation, while the use of a stethoscope is referred to as indirect auscultation.
Electronic stethoscopes are a newer version of the Laennec concept, in which skin-contacting diaphragms form an acoustic cavity in which the sound in air is converted into an electrical signal. These signals are amplified, filtered or otherwise processed and played through, for example, speakers or headphones. A large amount of body sound information is in the frequency band of 0.001Hz to 100Hz, and since the audibility threshold rises sharply below 100Hz, the amplification of the electrical signal makes it difficult to hear if it is not heard. Few current systems, even electronic stethoscope systems, are designed for accurate and efficient amplification within this range.
Disclosure of Invention
In various embodiments, acoustic-vibrating transducer devices according to the present invention are optimized for sensing and transducing acoustic phenomena occurring in a patient's body and manifest themselves on the skin surface at frequencies of 0.001Hz to 10 kHz. Strategies for effective coupling to the skin include properly mismatched mechanical impedances, the use of impedance matched gels or liquids, shaped (e.g., domed) microphones, material selection and/or peripheral leaf spring arrangements that allow relative motion between the inner portion and the peripheral diaphragm portion. The spring rate or spring compliance of the leaf spring can be selectively selected to optimize the frequency response of the sensor.
Accordingly, in a first aspect, the present invention relates to a sensor device. In various embodiments, the sensor device includes a diaphragm having an outer portion and an inner portion, the inner movable portion being attached to the outer portion by a plurality of leaf springs, limiting relative movement between the inner and outer portions; a coil disposed on at least one side of the diaphragm; and at least one magnet operatively arranged relative to the coil to cause current to flow through the coil by relative movement between the movable portion and the peripheral portion.
In some embodiments, the inner portion is fixed and the outer portion is movable relative thereto; in other embodiments, the outer portion is fixed and the inner portion is movable relative thereto. For example, in certain embodiments, the outer fixed portion of the diaphragm has a shape and the inner movable portion is defined within a plurality of slits through the diaphragm and arranged in series. The series defines a closed sequence concentric with and having the shape of the outer fixing portion, and each pair of slits is parallel and has an overlapping portion defining an insertion strip corresponding to one of the leaf springs and a non-overlapping portion. In some cases, the slits are filled with a thixotropic material. In some embodiments, the coil and at least one magnet are circular, while in other embodiments, one or both have different shapes.
In some embodiments, the magnets are a pair of magnet assemblies disposed on opposite sides of the diaphragm, each assembly including at least two concentric magnets. Each magnet has an isosceles trapezoidal cross-section with an angle of 45 ° ± 5 °. In various embodiments, the coil occupies 50% to 75% of the diaphragm area.
The sensor device may include a pickup structure extending from the diaphragm to contact a biological tissue surface. The diaphragm may have a modal contribution with a zero mean volumetric velocity to isolate a piston response of the diaphragm to a voltage generated in a direction perpendicular to the diaphragm. In some embodiments, the membrane is a composite sandwich panel comprising a core and an integral panel on each side of the core. For example, the panel may be a copper clad flexible printed circuit polymer film. The copper may be etched to ensure an isotropic mechanical resistance of 10% or less of the shortest planar dimension of the diaphragm. In some embodiments, the panel is made of a graphene composite structure, and the graphene may be etched to ensure isotropic mechanical impedance of 10% or less of the shortest planar dimension of the membrane.
In some embodiments, the diaphragm is asymmetrically biased in the non-energized state. The offset may be, for example, in the range of 0.1mm to 3 mm. The sound pickup structure may be dome-shaped and may or may not have surface features. If present, the surface may be raised, dimpled and/or corrugated. The pickup structure may have a mechanical impedance that is mismatched relative to the target surface.
In another aspect, the invention relates to an acoustic transducer. In various embodiments, an acoustic transducer includes a diaphragm including a peripheral portion and a central dome pickup portion; a holding member surrounding the diaphragm and configured to hold the diaphragm and allow at least a part of the movement when the acoustic energy is applied to the dome sound-collecting portion; a transducer for converting the motion of at least a portion thereof into an electrical signal.
The peripheral portion may be flat or, in some embodiments, may be an extension or peripheral edge of the dome. In various embodiments, the transducer includes at least one coil attached to the diaphragm and at least one magnet separate from the diaphragm but magnetically coupled to the coil. In other embodiments, the diaphragm is capacitive. The pickup portion may have a mechanical impedance that is mismatched relative to a target surface.
In some embodiments, the sensor is coupled to a Pinard horn, a conical fetal scope, which amplifies the sound of a fetal or neonatal heartbeat, and is described as an "ear horn" (hence, a longer cone (up to 30 "), the signal becomes unclear, but weak heart sounds are better picked up). The embodiment with binaural fetal mirror allows the user to hear the heartbeat through both ears, or can be recorded for reproduction in stereo. In one embodiment, the transducer is connected to a tapering device, the larger diameter end of which is configured to be placed on the chest wall.
As used herein, the terms "about", "about" and "substantially" mean ± 10%, in some embodiments ± 5%. Reference in the specification to "one example," "an example," "one embodiment," or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present technology. Thus, the appearances of the phrases "in one example," "in an example," "one embodiment," or "an embodiment" in various places throughout this specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, procedures, steps, or characteristics may be combined in any suitable manner in one or more examples of the present technology. The headings provided herein are for convenience only and are not intended to limit or interpret the scope or meaning of the claimed technology.
Drawings
The foregoing will be more readily understood from the following detailed description of the invention taken in conjunction with the accompanying drawings, in which:
FIG. 1A shows an exploded view of an acousto-vibration sensor according to an embodiment of the invention.
FIGS. 1B and 1C are a perspective view and a cross-sectional elevation view, respectively, of the sensor shown in FIG. 1A.
Fig. 2A is a top view of the interior of the diaphragm shown in fig. 1A-1C.
Fig. 2B is a bottom view of the interior of the diaphragm shown in fig. 1A-1C.
Fig. 2C is a perspective view illustrating the operation of the leaf spring of the diaphragm shown in fig. 1A-1C.
Fig. 3A and 3B show bottom and top views, respectively, of a top magnet assembly according to one embodiment of the present invention.
Fig. 3C shows a portion of the top magnet assembly in more detail.
Fig. 3D is a cross-sectional perspective view of a top and bottom magnet assembly according to one embodiment of the invention.
FIG. 4A is another cross-sectional elevation view of the sensor of FIG. 1, showing magnetic field lines produced by the top and bottom magnet assemblies.
FIG. 4B is another cross-sectional elevation view of the sensor of FIG. 1 having a rectangular, rather than trapezoidal, magnet.
Fig. 4C depicts a simulation showing tangential air gap flux density as a function of radius, in accordance with one embodiment of the present invention.
Fig. 4D depicts magnetic flux density as a function of height from the center of the diaphragm.
Fig. 5A-5F are top views of alternative diaphragm shapes.
Fig. 6A and 6B are a cross-sectional front view and an exploded view, respectively, of an embodiment of a sensor including a ferrofluid.
Fig. 6C is another cross-sectional elevation view of the sensor of fig. 6A and 6B, showing magnetic field lines produced by the magnet.
Detailed Description
An acousto-vibration sensor according to the present invention is shown at 100 in FIG. 1A. The
Referring to fig. 2A-2D, in one embodiment, the
The strip of
The slits also facilitate reducing the overall material content of the
Referring to fig. 2A, a
In the illustrated embodiment, the sub-coils 220a-220f are connected in series. Each end of the
In one embodiment, the sub-coils 220 disposed on the
In one example, a copper-clad flexible (e.g., polyimide) Printed Circuit Board (PCB) may be used to fabricate the
In another approach, conductive ink is selectively printed (e.g., by deposition or other additive techniques) on the substrate to form the
It should be noted that in some embodiments, a moving magnet is used rather than a moving coil. This can be accomplished by placing a magnet on the
The operation of the leaf spring is best shown in fig. 2C. As the
Fig. 3A-3D illustrate various features of the
Fig. 4A shows a further cross-sectional view of the
Fig. 4B shows the magnetic field within a magnet assembly with four magnets having a rectangular rather than trapezoidal cross-section, but using the same amount of material as in fig. 4A. Various other embodiments may use different magnet shapes or placements as long as interaction with the sub-coil pairs is maintained. In certain embodiments, the sub-coil pairs exist in three, four, five, etc. pairs.
In fig. 4C,
As will be understood by those skilled in the art, when current flows through a pair of sub-coils of the
In one embodiment, the direction of current flow through the pair of sub-coils is selected to cause the movable portion of the
Fig. 4D depicts a Finite Element Analysis (FEA) simulation of the magnet structure showing the axisymmetric tangential air gap flux density B · t (r) as a function of radius r (mm) at 1mm and 2mm pole spacing for BNP10 and Nd37 magnet materials. Fig. 4E depicts the magnetic flux density B · n (z)/Tesla (Tesla) as a function of the membrane center height z (mm) at 23.0mm from the magnet structure center r for BNP10 magnet material.
In the foregoing example, the shape of the
The
Diaphragm transducer constructions suitable for this purpose also include more conventional piston microphone arrangements with conventional capacitive (rather than coil-based) diaphragms. By mounting the microphones, they are very effective in coupling longitudinal pressure waves generated inside the body when they reach the skin surface, while transverse and bending waves of the skin surface can be eliminated. The pick-up ideally maximizes the signal-to-noise ratio by mechanically eliminating unwanted noise. For example, longitudinal sound emanating directly from an organ in the body (e.g. heart murmur, bowel movement or shoulder tendon clicks) is the first vibration to reach the microphone, while the system will mechanically cancel extraneous sound signals, such as reflections, skin movements or sound from surrounding tissue. As described below, a hemispherical rigid pickup may further enhance the first vibration mode measurements from the piston transducer of the target organ.
The membrane may be formed, for example, from a composite sandwich structure comprising or consisting of top and bottom layers (or "skins") of copper clad polyimide, sandwiching a core, for example, a rigid closed cell polymer foam, for example ROHACELL31IG Polymethacrylimide (PMI). The core and/or one or both skins may be monolithic panels (e.g. isotropic in the case of acrylic panels of thickness, for example 1.5mm, as compared to sandwich composite panels or two or more sections bonded together of greater thickness) which have an acoustically zero thickness. The copper cladding may be etched to ensure isotropic mechanical resistance of 10% or less of the shortest planar dimension (e.g., diameter) of the diaphragm.
The sandwich panel skin can be made using standard Flexible Printed Circuit (FPC) manufacturing techniques, using commercially available high performance copper clad polyimide, such as loose FELIOS R-F775 (8.7 to 17.4 μm copper foil on a 12.7 to 25.4 μm polyimide substrate) material, or standard RFID antenna manufacturing techniques using aluminum (5 to 10 μm) clad PET/polyester film (5 to 25 μm). The
In an alternative embodiment, the membrane may be an isotropic graphene skin composite sandwich panel, which may be fabricated using laser cutting or stamping from a mechanical press. This structure provides increased stiffness to the skin, reduced areal density to the mechanical properties of the panel, and increased electrical conductivity to the laser-cut planar voice coil.
Variations of the
In certain embodiments, the sound pickup 114 (e.g., dome) is fabricated to optimize size, shape, stiffness, and thickness parameters for bonding with the target tissue. For example, the target tissue region may be primarily divided into muscle, fat, or bone (e.g., pectoral muscle of the upper abdominal torso, stomach region under ribs, shoulder bone). A rigid, thin trigger dome will advantageously be in contact with adipose tissue, while a larger trigger dome will be more advantageously in contact with bone tissue than a larger trigger dome. The dome functions to transmit longitudinal pressure waves in the body that reach the tissue surface to transverse bending waves of the panel, albeit in the first vibration mode of the diaphragmBefore the start. The so-called fundamental mode frequency generally depends on the square root of the elastic stiffness (Young's modulus, E/GPa) of a material, divided by its mass density (p, kg/m)3). This dependence is simulated in fig. 4F, which includes finite element analysis simulations to compare the effects of the same size pan and dome and material. In particular, the dependency is graphically depicted in FIG. 4G, comparing a Carbon Fiber Reinforced Plastic (CFRP) pickup to other materials (e.g., stainless steel, fiberglass reinforced plastic, polymethylmethacrylate (acrylic, Plexiglas, Perspex Plexiglas, Lucite clear synthetic resin) PMMA, and polycarbonate, illustrates the performance advantage of a stiffer, lighter material (e.g., CFRP) with a very high yield strength.
Thus, the precise characteristics of the
Alternatively or additionally, various gels that advantageously match the mechanical impedance of various tissues may be applied to the microphone or target tissue prior to application of the sensor. (thus, while
In yet another embodiment,
In another alternative, the
The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. The described embodiments are, therefore, to be considered in all respects only as illustrative and not restrictive.
- 上一篇:一种医用注射器针头装配设备
- 下一篇:包括模式化电极的分布式模式扬声器致动器