Passive ultrasound needle probe locator

Claim 2

In a system for deriving an image of a region of a body by applying ultrasound energy to the region by means of an external transducer a probe and probe locator apparatus comprising: (a) hollow needle means thereby defining a probe for insertion into the body; and (b) ultrasonic energy transmission means, a portion of which is removably located within said hollow needle means, including (i) passive solid conduit means, removably carried within said needle means, for detecting ultrasound energy near the tip region of said needle means and for conveying said energy through said needle means and outside the body; and (ii) electrically active ultrasound transducer means coupled to receive ultrasonic energy from said conduit means outside the body and adapted to produce an output signal to said system indicative thereof, whereby the location of the probe within the image area may be determined.

Claim 3

Apparatus as described in claim 1 wherein said conduit means comprises a solid, sonically conductive rod extending inside said needle means and terminating in an oblique surface cross-section.

Claim 4

Apparatus as described in claim 2 wherein said conduit means includes a matching layer, attached to said cross-section, for coupling incident sonic energy to said rod.

Claim 5

Apparatus as described in claim 2 wherein said rod is sized in cross-section to form a high sonic impedance gap to the inner surface of said needle means.

Claim 6

Apparatus as described in claim 4 wherein said gap is formed of air, and wherein said conduit means forms an annular liquid tight seal near the inserted extremity of said needle means.

Claim 7

Apparatus as described in claim 2 wherein said rod consists essentially of stainless steel.

Claim 8

Apparatus as described in claim 2 wherein said rod makes periodic, relatively short contacts with the inner surface of said needle means.

Claim 9

Apparatus as described in claim 7 wherein said rod defines periodic annular ridges spanning a gap between said rod and said needle means.

Claim 10

Apparatus as described in claim 7 wherein said rod defines a helical ridge spanning a gap between said rod and said needle means.

Claim 11

Apparatus as described in claim 1 wherein said conduit means and said transducer means are coupled to one another by simple mechanical contact.

Claim 12

Apparatus as described in claim 1 wherein said conduit means are coupled to one another through a fluid sonic coupling medium.

Claim 13

In a system for deriving an image of a region of a body by applying ultrasound energy to the region by means of an external transducer probe locator apparatus comprising: (a) hollow needle means for insertion into the body; (b) conduit means, carried within said needle means, for detecting ultrasound energy near the tip region of said needle means and for conveying said energy through said needle means and outside the body; and (c) ultrasound transducer means coupled to receive energy from said conduit means outside the body, wherein said conduit means comprises a solid, sonically conductive rod extending inside said needle means and terminating in an oblique surface cross-section, and wherein said conduit means comprises plural solid rods carried within said needle means and extending respective plural different distances into the body, thereby providing means for sensing the timed receipt of sonic pulses at said distances, and hence the direction and propagation speed of sonic energy in the body.

Claim 14

In a system for deriving an image of a region of a body by applying ultrasound energy to the region by means of an external transducer probe locator apparatus comprising: (a) hollow needle means for insertion into the body; (b) conduit means, carried within said needle means, for detecting ultrasound energy near the tip region of said needle means and for conveying said energy through said needle means and outside the body; and (c) ultrasound transducer means coupled to receive energy from said conduit means outside the body, wherein said conduit means comprises a solid, sonically conductive rod extending inside said needle means and terminating in an oblique surface cross-section, and wherein said conduit means comprises plural solid rods carried within said needle means and extending respective plural different distances into the body, thereby providing means for sensing the timed receipt of sonic pulses at said distances, and hence the direction and propagation speed of sonic energy in the body.

Claim 15

In a system for deriving any image of a region of a body by applying ultrasound energy to the region by means of an external transducer probe locator apparatus comprising: (a) hollow needle means for insertion into the body; (b) conduit means, carried within said needle means, for detecting ultrasound energy near the tip region of said needle means and for conveying said energy through said needle means and outside the body; and (c) ultrasound transducer means coupled to receive energy from said conduit means outside the body, wherein said conduit means comprises a solid, sonically conductive rod extending inside said needle means and terminating in an oblique surface cross-section, wherein said rod makes periodic, relatively short contacts with the inner surface of said needle means, and wherein said rod is helical in configuration, thereby making periodic contact with the inner surface of said needle means.

Claim 16

In a system for deriving any image of a region of a body by applying ultrasound energy to the region by means of an external transducer probe locator apparatus comprising: (a) hollow needle means for insertion into the body; (b) conduit means, carried within said needle means, for detecting ultrasound energy near the tip region of said needle means and for conveying said energy through said needle means and outside the body; and (c) ultrasound transducer means coupled to receive energy from said conduit means outside the body, wherein said conduit means comprises a solid, sonically conductive rod extending inside said needle means and terminating in an oblique surface cross-section, wherein said rod makes periodic, relatively short contacts with the inner surface of said needle means, and wherein said rod is helical in configuration, thereby making periodic contact with the inner surface of said needle means.

Claim 19

A method as described in claim 14 and further comprising the steps of generating a sonic pulse outside said body, sending said generated pulse down said conduit means through said needle probe, and conditioning said external transducer means to detect dispersed sonic energy from said conduit means distal tip into the body of the subject.

Claim 20

A method as described in claim 15 wherein said sonic pulse is coupled to said conduit means outside said body at approximately the same time an imaging pulse is generated at said external transducer means.