Apparatus for injecting a liquid into live animals
An apparatus for injecting a liquid into live animals, comprising a cradle plate ( 18 ) having a cradle ( 24 ) for accommodating at least a part of an animal, sensors ( 20 - 1, 20 - 2, 20 - 3 ) for detecting a force acting upon the cradle plate, an injection mechanism ( 16 ) for injecting liquid into the animal, and a control unit ( 38 ) for triggering the injection mechanism ( 16 ) in response to signals received from the sensors, wherein at least three sensors ( 20 - 1 -, 20 - 2, 20 - 3 ) are arranged for measuring forces with which the cradle plate ( 18 ) is pressed against a base ( 12 ) in at least three non-aligned positions, and the control unit ( 38 ) is adapted to trigger the injection mechanism ( 16 ) when the forces measured by the sensors are distributed according to a predetermined pattern.
1. An apparatus for injecting a liquid into live animals, comprising a movable cradle plate ( 18 ) having a cradle ( 24 ) for accommodating at least a part of an animal, a plurality of sensors comprising at least three sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) for detecting a plurality of forces (ΔF 1 , ΔF 2 , ΔF 3 ) acting upon the cradle plate, an injection mechanism ( 16 ) for injecting the liquid into the animal, and a control unit ( 38 ) for triggering the injection mechanism ( 16 ) in response to signals received from the plurality of sensors, characterized in that the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) are arranged for measuring the plurality of forces (ΔF 1 , ΔF 2 , ΔF 3 ) with which the cradle plate ( 18 ) is pressed against a base ( 12 ) in at least three non-aligned positions, and the control unit ( 38 ) is adapted to trigger the injection mechanism ( 16 ) when the plurality of forces measured by the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) are distributed according to a predetermined pattern;
wherein the plurality of sensors are arranged so that the plurality of sensors do not come into direct contact with the animal;
wherein the cradle plate ( 18 ) is held in position on the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ), and the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) contact the bottom of the cradle plate ( 18 );
wherein one end of each of the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) is secured on the base ( 12 ) whereas the opposite end of each of the plurality of sensors supports the cradle plate ( 18 ); and
wherein the cradle plate ( 18 ) is configured to exert a force upon the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) when the cradle plate ( 18 ) is pressed against the base ( 12 ), which force results in a strain applied to the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ); whereby the cradle plate ( 18 ) moves towards the base ( 12 ).
2. The apparatus according to claim 1 , wherein the control unit ( 38 ) is adapted to compare the detected plurality of forces (ΔF 1 , ΔF 2 , ΔF 3 ) to corresponding target values (ΔFt) and to trigger an injection when deviations of the detected plurality of forces from the corresponding target values are below predetermined limits.
3. The apparatus according to claim 1 , wherein positions where the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) contact the cradle plate ( 18 ) are disposed outside of a footprint of the cradle ( 24 ).
4. The apparatus according to claim 1 , wherein the cradle ( 24 ) has an axis of symmetry and the positions of the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ), as seen in a plan view of the cradle plate ( 18 ), form an isosceles triangle with one corner located on the axis of symmetry in a vicinity of a portion of the cradle corresponding to a rear part of the animal, and with a base of the isosceles triangle being located on a side of the cradle corresponding to a head of the animal.
5. The apparatus according to claim 4 , wherein the cradle plate ( 18 ) comprises three magnets or magnetisable elements ( 32 ), at sites corresponding to the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ).
6. The apparatus according to claim 5 , wherein the cradle plate ( 18 ) is provided with a machine readable code, wherein said machine readable code provides information on an identity of the cradle plate.
7. The apparatus according to claim 6 that further comprises instructions for setting an angle formed between two needles ( 44 ).
8. The apparatus according to claim 7 , wherein the cradle plate ( 18 ) is one of a plurality of exchangeable cradle plates, and the control unit ( 38 ) is adapted to read a code on the plurality of exchangeable cradle plates, which code provides information on an identity of the plurality of exchangeable cradle plates, and to provide instructions for setting the angle formed between the longitudinal direction of the two needles ( 44 ).
9. The apparatus according to claim 1 , wherein the cradle plate ( 18 ) is adapted to be held on the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) by magnetic attraction.
10. The apparatus according to claim 1 , wherein the injection mechanism ( 16 ) comprises two injection needles ( 44 ), wherein each of the two injection needles is held by its respective needle holder ( 40 ), and wherein the two needle holders ( 40 ) are actuated by a common actuating mechanism for advancing the two injection needles to penetrate a skin of the animal.
11. The apparatus according to claim 10 , wherein each needle holder ( 40 ) is mounted on its respective guide block ( 52 ) so that each needle holder will slide in its respective guide block in a longitudinal direction of the two respective injection needles ( 44 ), and wherein the actuating mechanism comprises articulated links ( 58 ) connecting the needle holders ( 40 ) to a common carriage ( 56 ) that is driven to move along an axis that bisects an angle formed between the longitudinal directions of the two needles ( 44 ).
12. The apparatus according to claim 11 , wherein the angle formed between the longitudinal directions of the two needles ( 44 ) is adjustable.
13. The apparatus according to claim 12 , wherein the cradle plate ( 18 ) is one of a plurality of exchangeable cradle plates, and the control unit ( 38 ) is adapted to read a code on the plurality of exchangeable cradle plates, which code provides information on an identity of the plurality of exchangeable cradle plates, and to provide instructions for setting the angle formed between the longitudinal direction of the two needles ( 44 ).
14. The apparatus according to claim 1 , comprising a metering and supply mechanism ( 14 ) for supplying the liquid to the injection mechanism ( 16 ), said measuring and supply mechanism comprising a backing plate ( 90 ) that supports a portion of a flexible tube ( 70 ) connecting a needle ( 44 ) of the injection mechanism ( 16 ) to a liquid source, the mechanism further comprising a lever ( 94 ) driven to pivot against the backing plate ( 90 ) and carrying a pressure member ( 98 ) arranged to quench the tube ( 70 ) against the backing plate ( 90 ) so as to squeeze-out a metered amount of liquid.
15. The apparatus according to claim 14 , wherein the backing plate ( 90 ) has a backing member ( 92 ) that is adjustable relative to the pressure member ( 98 ) for adjusting the metered amount of liquid.
16. The apparatus according to claim 14 that comprises at least one slot for detachably inserting a liquid source ( 86 ), and a reader ( 118 ) adapted to read a code from the liquid source, which code includes information on the liquid, and the control unit ( 38 ) is adapted to derive at least one injection parameter from the information read by the reader ( 118 ).
17. The apparatus according to claim 1 , wherein the cradle plate ( 18 ) is supported on the base ( 12 ) by the plurality of sensors ( 20 - 1 , 20 - 2 , 20 - 3 ); and
wherein the cradle plate has magnetizable material ( 32 ) on the bottom side, and the sensors ( 20 - 1 , 20 - 2 , 20 - 3 ) comprise a magnet ( 34 ), and said magnetizable material ( 32 ) is attracted to the magnet ( 34 ).