Ultrasonic coupler

• US 5,575,291 A
• Filed: 09/15/1994
• Issued: 11/19/1996
• Est. Priority Date: 11/17/1993
• Status: Expired due to Fees

• Current Assignee: Fukuda Denshi Company Limited
• Original Assignee: Fujitsu Limited
• Inventors: Matsui, Kiyoto, Hayakawa, Kenichi
• Primary Examiner(s): JAWORSKI, FRANCIS J
• Application Number:
  US08/306,320
• Time in Patent Office: 796 Days
• Field of Search: 128/662.03, 128/663.01, 426/1, 522/5, 525/55
• US Class Current: 600/459
• CPC Class Codes: C08J 2329/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08J 3/075 Macromolecular gels
• CPC Class Codes: G10K 11/02 Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators

Abstract

An ultrasonic coupler to be arranged between an ultrasonic probe and a patient to be examined using an ultrasonic diagnostic apparatus is provided. A method of producing the ultrasonic coupler is also provided. The ultrasonic coupler is made of a gel material having no tackiness. According to the present invention, an ultrasonic coupler includes the gel material which contains polyvinyl alcohol in the range of 3 weight % to 6 weight %. The polyvinyl alcohol is at least 98.0 mole % in the degree of saponification, and the gel material has a hardness in the range of 0.5×10⁴ dyne/cm² to 2×10⁴ dyne/cm². A coupling member for holding the ultrasonic coupler in contact with the ultrasonic probe is fixed to the gel material. The method of producing the ultrasonic coupler includes a step of providing a mold having an interior chamber. A coupling member projects into the interior chamber, and has an attachment portion inserted into the mold. The attachment portion has a shape adapted for fitting on the ultrasonic probe. An aqueous solution is injected into the interior chamber. After the injection, at least one operation of freezing and defrosting the aqueous solution is performed, thereby transforming the aqueous solution into a gel material. Finally, the mold is separated from the gel material while allowing the coupling member to be embedded in the gel material with the attachment portion protruding from the gel material.

Claims

1. An ultrasonic device comprising a gel material containing polyvinyl alcohol PVA in the range of 3 weight % <

PVA<

6 weight %, the polyvinyl alcohol having a degree of saponification of at least 98 mole % and the gel material having a hardness in the range of 0.5×

10⁴ dyne/cm² to 2×

10⁴ dyne/cm².

2. An ultrasonic device according to claim 1, wherein the polyvinyl alcohol has a degree of saponification of at least 99 mole %.

3. An ultrasonic device according to claim 1, further comprising a coupling member for releasably coupling said gel material to an ultrasonic probe, said coupling member being fixed to said gel material.

4. An ultrasonic device according to claim 3, wherein said coupling member is fixed to said gel material by being embedded in a gelatinous mass of said gel material.

5. An ultrasonic device according to claim 3, wherein said coupling member has holes therethrough which are embedded in a gelatinous mass of said gel material, with gel material passing through the holes, thereby fixing the gel material to the coupling member.

6. An ultrasonic device according to claim 1, wherein the gel material has a hardness in the range of 1×

10⁴ dyne/cm² m 2×

10⁴ dyne/cm².