US3827115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a catheter
Assignee: Erasmus University Rotterdam
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Filing: 1973-02-21
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Granted: 1974-08-06
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Expires: 1993-02-21
Abstract
Abstract A device for examining the heart is provided with a catheter adapted to be placed within the heart and including at one end thereof, circumferentially arranged, equidistantly distributed elements, serving for the transmission and reception of ultrasonic waves. The catheter has an axis and the elements have no directivity in a plane perpendicular to this axis. The elements are so dimensioned in axial direction that in a plane through the axis they do show directivity. An excitation device is provided which successively excites groups of adjacently arranged elements and time delays are provided for delaying the transmitted and received pulses for the elements of a group that the differences in travel times are compensated. An adder is provided for the summation of echo pulses and a device is provided for visually displaying the part of the examined heart surrounding the catheter. A method is provided whereby the elements are provided on the catheter by positioning a piezoelectric cylinder on a core and thereafter sawing through the cylinder along a plurality of radial planes interspaced at equal angular distances. The catheter which is derived from the method is also part of the invention.
Inventors
- 👤 N Bom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:07
CPC Classifications
A; A61; A61B; A61B8/00; A61B8/12; A61B8/44; A61B8/4444; A61B8/445; A61B8/4483; A61B8/4488; A61M; A61M25/00; A61M25/0009; A61M25/0067; A61M25/0068; A61M25/0069; B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0607; B06B1/0622; B06B1/0633; G; G10; G10K; G10K11/00; G10K11/18; G10K11/26; G10K11/34; G10K11/341; G10K11/345; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
243 words
A method of manufacturing a catheter for examining a hollow organ with the aid of ultrasonic waves, said catheter having circumferentially arranged, equidistantly distributed elements, said method comprising; providing a basic member which is a substantially cylindrical core of insulating material, the outer surface of which is provided with a layer of conductive material, locally removing the conductive material to divide the layer into two sections constituting a front and a rear section, respectively, which are insulated from each other, placing on part of the outer surface of said core exposed by the removing of the conductive material a hollow cylinder of piezoelectric material, the cylinder being so polarized that in radial direction a resonance takes place for ultrasonic waves to be generated, the two cylinder surfaces having electrodes in the form of layers, which are each connected to a respective one of the sections of the conductive layer on the core, after which the piezoelectric cylinder and the outer conductive layer of the core are sawn through along a plurality of radial planes interspaced at equal angular distances, so that a plurality of separate piezoelectric elements are formed each element having a corresponding conductive area on said core, connecting one of the electrodes of each element via its corresponding area of the conductive layer of the core to a corresponding feed wire and connecting the other electrode of said each element via another part of the conductive layer to a communal conductor.
Claim 2
Independent Claim
243 words
A method of manufacturing a catheter for examining a hollow organ with the aid of ultrasonic waves, said catheter having circumferentially arranged, equidistantly distributed elements, said method comprising; providing a basic member which is a substantially cylindrical core of insulating material, the outer surface of which is provided with a layer of conductive material, locally removing the conductive material to divide the layer into two sections constituting a front and a rear section, respectively, which are insulated from each other, placing on part of the outer surface of said core exposed by the removing of the conductive material a hollow cylinder of piezoelectric material, the cylinder being so polarized that in radial direction a resonance takes place for ultrasonic waves to be generated, the two cylinder surfaces having electrodes in the form of layers, which are each connected to a respective one of the sections of the conductive layer on the core, after which the piezoelectric cylinder and the outer conductive layer of the core are sawn through along a plurality of radial planes interspaced at equal angular distances, so that a plurality of separate piezoelectric elements are formed each element having a corresponding conductive area on said core, connecting one of the electrodes of each element via its corresponding area of the conductive layer of the core to a corresponding feed wire and connecting the other electrode of said each element via another part of the conductive layer to a communal conductor.
Claim 3
Dependent Claim
28 words
A method as claimed in claim 1, comprising providing the core with a central bore through which either the communal conductor or the separate feed wires are passed.
Claim 4
Dependent Claim
41 words
A method as claimed in claim 2, wherein the communal conductor is passed through the bore, this conductor being connected to the outer electrodes of the elements by means of a metal cap provided on the leading end of the catheter.
Claim 5
Dependent Claim
31 words
A method as claimed in claim 3, the conductive layer initially covering the entire outer surface of the core, wherein this layer is removed from the rear end-face of the core.
Claim 6
Dependent Claim
21 words
A method as claimed in claim 1, wherein the piezoelectric cylinder is bonded to the core by means of an adhesive.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 1, wherein the electrodes are bonded to the two parts of the conductive layer of the core by soldering.
Claim 8
Dependent Claim
31 words
A method as claimed in claim 1, wherein the catheter is secured to the catheter tube by means of a coupling member which engages with the rear part of the core.
Claim 9
Dependent Claim
32 words
A method as claimed in claim 1, wherein the core is at its leading end provided with an expanded part whose diameter is equal to the outer diameter of the piezoelectric cylinder.
Claim 10
Dependent Claim
32 words
A method as claimed in claim 1, wherein the feed wires are passed through the catheter tube in bundles, the feed wires of each group of elements all belonging to different bundles.
Claim 11
Dependent Claim
50 words
A method as claimed in claim 1, wherein the sawing through of the piezoelectric cylinder and the outer layer of the core is effected by means of a circular saw, the core being provided with an end piece which is clamped during sawing and removed when the sawing is finished.
Claim 12
Dependent Claim
41 words
A method as claimed in claim 1, wherein the sawing through of the piezoelectric cylinder and the outer layer of the core is effected with the aid of a wire, the core being clamped up with the aid of centering members.
Claim 13
Dependent Claim
20 words
A method as claimed in claim 1, wherein the catheter is finished by covering it with a thin protective coating.
Claim 14
Dependent Claim
17 words
A method as claimed in claim 12, wherein the layer is given a thickness of one-fourth wavelength.
Claim 15
Dependent Claim
12 words
A method according to claim 13, wherein said layer is an epoxy-resin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |