Amniocentesis needle with improved sonographic visibility
OwnerRobert Hurwitzinventor
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Abstract
Disclosed is a medical cannula or amniocentesis needle of improved sonographic visibility. The invention comprises a needle or cannula having one or more sounding apertures formed therein. The diameter of each sounding aperture is substantially equal to a predetermined wavelength of an incident ultrasonic beam. As a result, the beam will diffract upon striking the sounding aperture and the resultant echo will ddiffuse isotropically therefrom, thereby improving the ultrasonic detectability thereof.
Claims22
A cannula for use in medical procedures wherein ultrasonic imaging of the cannula is achieved by directing an incident ultrasonic beam of known wavelength against the cannula, said cannula comprising:
- a generally tubular cannula body having a proximal end, a distal end, a generally cylindrical wall, and a hollow inner lumen extending axially therethrough;
- at least one generally round sounding aperture formed in said cannula wall, the diameter of said sounding aperture being approximately equal to the known wavelength of said incident ultrasonic beam.
An amniocentesis needle of improved sonographic visibility comprising:
- a generally tubular needle body having a proximal end, a distal end, a generally cylindrical wall, and a hollow inner lumen extending axially therethrough;
- a connecting hub formed on said proximal end;
- a tissue penetrating bevel located on the distal tip of said needle and operative to effect transabdominal penetration and intraamnionic positioning of at least the distal end of the needle;
- and
- at least one generally round sounding aperture formed in the needle wall, the diameter of said sounding aperture being substantially equal to an incident ultrasonic beam wavelength between 0.15 and 0.54 mm so as to improve the imagability of acoustical return signals which emanate from the needle wall when an incident ultrasonic beam having a wavelength substantially equal to the diameter of the diameter of said sounding apertures is directed against said needle wall.
Dependencies are inferred from the claim text.