1. An apparatus for obtaining a tissue sample, the apparatus comprising:
(a) a biopsy probe, the biopsy probe comprising:
(i) a cannula having a closed distal end, wherein the cannula defines a longitudinal axis and a side aperture proximal to the closed distal end, wherein the cannula has a first length, and
(ii) a cutter positioned within the cannula, wherein the cutter is operable to move within the cannula to cut a tissue sample from tissue protruding through the side aperture; and
(b) a blocking member movably coupled with the cannula, wherein the blocking member has a second length and a distal end having a tapered portion, wherein the second length is less than the first length, the blocking member comprising:
(i) an elongate structure registered to at least partially encompass and engage the cannula, wherein the elongate structure is open and flexible to provide snap-on engagement of the blocking member with the cannula by snapping the blocking member onto the cannula in a direction transverse to the longitudinal axis, wherein the blocking member is configured to slide along the cannula while the blocking member is snapped onto the cannula, wherein a portion of the elongate structure is mounted along the cannula such that the elongate structure blocks at least part of the side aperture and is further positioned such that the cannula and the elongate structure are operable to slidingly enter tissue with the tapered portion, and
(ii) a gripping portion attached to a proximal portion of the elongate structure for longitudinally positioning the blocking member relative to the side aperture, wherein the elongate structure extends distally from the gripping portion.
2. The biopsy device of claim 1, wherein the blocking member comprises a probe sleeve.
3. The biopsy device of claim 2, wherein the probe sleeve comprises a collar selectively detachable from the cannula.
4. The biopsy device of claim 2, further comprising;
(a) a vacuum assistance system; and
(b) a vacuum lumen attached along a length of the cannula, wherein the vacuum lumen is in fluid communication with the interior of the cannula, wherein the vacuum lumen is further in fluid communication with the vacuum assistance system;
wherein the probe sleeve further comprises a circumferential portion shaped to engage the cannula and vacuum lumen.
5. The biopsy device of claim 2, wherein the probe sleeve includes a proximally attached actuator shaped to be grasped by a user.
6. The biopsy device of claim 1, wherein the cannula includes a piercing tip, wherein a dead space longitudinal distance from a distal end of the side aperture to a distal-most end of the piercing tip is less than 7.8 mm.
7. The biopsy device of claim 6, wherein the dead space longitudinal distance is approximately 6 mm.
8. The biopsy device of claim 1, wherein the closed distal end of the cannula includes a tissue piercing tip.
9. The biopsy device of claim 1, wherein the cutter is translatable within the cannula to sever tissue protruding through the side aperture.
10. The biopsy device of claim 9, further comprising a cutter drive assembly operable to distally translate the cutter across the side aperture to sever tissue protruding through the side aperture.
11. The biopsy device of claim 1, wherein the elongate structure of the blocking member is dimensioned to be inserted in tissue with the cannula.
12. The biopsy device of claim 1, wherein the blocking member is slidable along at least a portion of first length of the cannula to selectively vary the effective size of the side aperture.
13. The apparatus of claim 1, wherein the cannula defines a cutter lumen and a vacuum lumen, wherein the cutter is positioned within the cutter lumen, wherein the elongate structure registers to at least a portion of the cutter lumen and vacuum lumen.
14. A biopsy device, comprising:
(a) an outer tube having a closed distal end, the outer tube defining a side aperture proximal to the closed distal end, wherein the outer tube provides an exterior, wherein the outer tube defines a longitudinal axis;
(b) a hollow cutter longitudinally movable within the outer tube to sever tissue prolapsed through the side aperture; and
(c) a blocking member, wherein the blocking member terminates at a tapered distal edge, at a proximal edge, and at a pair of lateral edges extending longitudinally from the tapered distal edge to the proximal edge, wherein the configuration and relative positioning of the tapered distal edge, proximal edge, and lateral edges of the blocking member are configured to permit the blocking member to be snappingly coupled to the exterior of the outer tube by pushing the blocking member onto the outer tube along a direction transverse to the longitudinal axis, wherein the tapered distal edge and the lateral edges of the blocking member define an elongate portion of the blocking member, wherein the blocking member further comprises a flange extending outwardly from a proximal portion of the elongate portion, wherein the blocking member is configured to slide along the exterior of the outer tube between at least a first proximal position and a second distal position while the blocking member is snapped onto the exterior of the outer tube, wherein the blocking member in the first proximal position is located proximally in relation to the side aperture, wherein at least a portion of the blocking member in the second distal position obstructs at least part of the side aperture.
15. The biopsy device of claim 14, wherein the blocking member defines a gap between the lateral edges permitting the blocking member to be selectively coupled with or decoupled with the cannula.
16. The biopsy device of claim 14, wherein the blocking member is configured to longitudinally translate relative to the outer tube to selectively cover at least a portion of the side aperture.
17. The biopsy device of claim 14, wherein the elongate portion of the blocking member is sized and shaped to permit a distal portion of the elongate portion to be distally inserted into tissue with the outer tube.
18. An apparatus for obtaining a tissue sample, the apparatus comprising:
(a) a biopsy probe, the biopsy probe comprising:
(i) a cannula having a closed distal end, wherein the cannula defines a side aperture proximal to the closed distal end, wherein the cannula has a first length, wherein the cannula defines a pinched lateral waist extending longitudinally along at least a portion of the length of the cannula, and
(ii) a cutter positioned within the cannula, wherein the cutter is operable to move within the cannula to cut a tissue sample from tissue protruding through the side aperture; and
(b) a blocking member movably coupled with the cannula, wherein the blocking member has a second length, wherein the second length is less than the first length, the blocking member comprising:
(i) an elongate structure registered to at least partially encompass and engage the cannula, wherein the elongate structure defines at least one ridge, wherein the elongate structure is open and flexible to provide snap-on engagement of the blocking member with the cannula by snapping the blocking member onto the cannula in a direction transverse to a longitudinal axis defined by the cannula and by engaging the pinched lateral waist with the at least one ridge, wherein the elongate structure has a beveled distal edge shaped to enter tissue with the cannula, and
(ii) a gripping portion attached to a proximal portion of the elongate structure for longitudinally positioning the blocking member relative to the side aperture,
wherein the elongate structure extends distally from the gripping portion while the blocking member is coupled with the cannula,
wherein the gripping portion is positioned proximal to the elongate structure while the blocking member is coupled with the cannula.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A liquid fluoride salt cooled, high temperature reactor, comprising:
a pebble-bed reactor core configured for containment within a reactor vessel;
wherein the reactor core comprises a pebble injection inlet located at a bottom end of the reactor core and a pebble defueling outlet located at a top end of the reactor core;
said reactor core cooled by a liquid fluoride salt coolant;
said reactor core comprising an inner reflector, outer reflector, and an annular pebble-bed region comprising an annular channel disposed in between the inner reflector and outer reflector;
said annular channel configured for receiving pebble fuel comprising a combination of seed and blanket pebbles having a density lower than the coolant such that the pebbles have positive buoyancy and migrate upward in said annular pebble-bed region toward the defueling outlet;
said annular pebble-bed region comprising a pebble injection annulus extending from the pebble injection inlet, the pebble injection annulus leading into a diverging annular conical region at the bottom end of the reactor core, and converging annular conical region leading into a pebble defueling slot at the top end of the reactor core; and
wherein the annular pebble-bed region comprises alternating radial layers of seed pebbles and blanket pebbles
wherein inner reflector comprises an inlet plenum leading to a plurality of inner injection ports in the bottom end of the pebble bed region;
wherein the inlet plenum is configured to inject coolant into the annular pebble bed region via the plurality of inner injection ports;
wherein the outer reflector comprises a plurality of outlet ports in the top end of the pebble bed region, the outlet ports leading to an outlet plenum;
wherein the pebble bed region is configured such that the coolant exits the pebble bed region primarily into the outlet ports in the outer reflector;
wherein the location of the coolant injection and outlet ports is selected to generate a radially outward and upward flow of coolant through the pebble bed region.
2. A reactor as recited in claim 1, wherein the annular pebble bed region comprises a driver fuel layer disposed between an inner radial blanket pebble layer and outer radial pebble blanket layer;
the inner radial blanket pebble layer being adjacent the inner reflector, and outer radial pebble blanket layer being adjacent the outer reflector.
3. A reactor as recited in claim 2, wherein the driver fuel layer comprises a plurality of axial layers comprising alternating seed and blanket pebble zones;
the alternating seed and blanket pebble zones configured to allow reduced power peaking.
4. A reactor as recited in claim 3, wherein the blanket pebbles comprise graphite blanket pebbles or thorium-bearing blanket pebbles containing coated particles of thorium.
5. A reactor as recited in claim 4, wherein the blanket pebbles comprise a mixture of thorium and uranium.
6. A reactor as recited in claim 4, wherein the seed pebbles comprise coated particles containing fissile uranium or plutonium fuel.
7. A reactor as recited in claim 6, wherein the seed pebbles comprise recycled U-233, plutonium, or a mixture of plutonium and other transuranics.
8. A reactor as recited in claim 2, further comprising:
a plurality of partition rings disposed at the pebble injection inlet;
wherein the partition rings control the radial location for pebbles injected into the annular pebble-bed region to generate the alternating radial layers of seed pebbles and blanket pebbles.
9. A reactor as recited in claim 2, further comprising:
a plurality of dividers disposed at the pebble injection inlet;
wherein the dividers control the azimuthal location for pebbles injected into the annular pebble-bed region to generate alternating azimuthal layers of seed pebbles and blanket pebbles.
10. A reactor as recited in claim 8, wherein the partition rings comprise an outer partition ring that delineates the outer radial blanket pebble layer from the driver fuel layer provide shielding of the outer reflector from neutrons generated by fission in seed pebbles, and an inner partition ring that delineates the inner radial blanket-pebble zone from the driver fuel layer to provide shielding of the inner reflector from neutrons generated by fission in seed pebbles.
11. A reactor as recited in claim 1, wherein the pebble injection annulus and the pebble defueling slot are configured to be substantially subcritical.
12. A reactor as recited in claim 1, wherein the angle of the coolant flow reaching the outer reflector is configured such that a transverse hydrodynamic force on the pebbles is capable of overcoming friction between the pebbles and outer reflector.
13. A reactor as recited in claim 1:
wherein the outer reflector further comprises a plurality of outer injection ports leading into the bottom end of the pebble bed region;
wherein the reactor is configured such that coolant may be injected into the lower portion of the annular pebble bed core from the outer injection ports of the outer reflector and oscillated periodically between the outer injection ports and inner injection ports to agitate the pebble bed.
14. A reactor as recited in claim 1:
wherein the inner reflector has a control channel at its center;
wherein the control channel is configured such that pebbles may be injected at a bottom inlet of the control channel, and defueled from a top outlet of the control channel; and
wherein reactivity of the reactor may be controlled by varying the rate of injection and defueling of pebbles into the control channel to vary the inventory of pebbles in the channel.
15. A reactor as recited in claim 1, further comprising:
a pebble injector at the pebble bed inlet;
the pebble injector comprising a plurality of entrance vanes;
wherein a coolant flow entering the bottom of the pebble injection annulus is swirled by the entrance vanes; and
wherein the swirling flow in the annulus alters a deposition pattern of injected pebbles at a bottom of the pebble bed.
16. A reactor as recited in claim 1:
wherein the defueling slot is configured to permit sufficient residence time for decay of short-lived fission products prior to removal from the core.
17. A reactor as recited in claim 3:
wherein the outer radial pebble blanket layer is configured to provide neutron shielding.