Pressure sensing assembly and method for an infusion pump
A pressure sensing assembly for an infusion pump, including: a tubing guide arranged to receive tubing; a displaceable load assembly at least partially disposed within the tubing guide and with a first surface facing in a first direction; a load cell facing the load assembly in the first direction; and a displacement assembly engaged with the tubing guide, facing the first surface in a second direction, opposite the first direction, and exerting a first force on the load assembly in the first direction. The load cell is arranged to detect a second force, greater than the first force, acting on the load cell in the second direction.
1. A pressure sensing assembly for an infusion pump, comprising:
a tubing guide arranged to receive tubing;
a displaceable load assembly at least partially disposed within the tubing guide and with at least one first surface facing in a first direction;
a load cell facing the load assembly in the first direction; and,
a displacement assembly engaged with the tubing guide, facing the at least one first surface in a second direction, opposite the first direction, and exerting a first force on the load assembly in the first direction, wherein the load cell is arranged to detect a second force, greater than the first force, acting on the load cell in the second direction.
2. The pressure sensing assembly of claim 1 , wherein the displacement assembly includes a plurality of magnets.
3. The pressure sensing assembly of claim 1 , wherein the load assembly is displaceable in the first and second directions.
4. The pressure sensing assembly of claim 1 , further comprising a shim disposed between the load assembly and the load cell.
5. The pressure sensing assembly of claim 1 , wherein the displacement assembly is arranged to draw at least a portion of the load assembly toward the tubing guide.
6. The pressure sensing assembly of claim 1 , wherein the load assembly includes:
a load plate; and,
an attraction plate fixed to the load plate, including the at least one first surface, and upon which the first force is exerted.
7. The pressure sensing assembly of claim 6 , wherein:
the displacement assembly includes a plurality of magnets; and,
the attraction plate is magnetic.
8. The pressure sensing assembly of claim 1 , further comprising a pusher assembly displaceable in the second direction to assume a fixed position facing the load assembly in the second direction, wherein:
in the fixed position, the pusher assembly is arranged to compress the tubing; and,
the load cell is arranged to detect:
the second force in response to the disposition of the pusher assembly in the fixed position; and,
a variation in the second force with the pusher assembly in the fixed position.
9. The pressure sensing assembly of claim 8 , wherein the load cell is arranged to detect a variation in the second force due to a pressure variation in the tubing.
10. A pressure sensing assembly for an infusion pump, comprising:
a tubing guide with at least one slot;
tubing including a longitudinal axis and at least a portion disposed in the at least one slot;
a displaceable load assembly at least partially disposed within the tubing guide and with a first surface in contact with the tubing;
a load cell facing the longitudinal axis in a first direction; and,
a displacement assembly facing at least a portion of the load assembly in a second direction, opposite the first direction, and exerting a first force on the load assembly in the first direction, wherein:
in response to a second force, greater than the first force, on the first surface, the load assembly is arranged to displace in the second direction; and,
the load cell is arranged to detect the second force.
11. The pressure sensing assembly of claim 10 , wherein the load assembly includes:
a load plate including the first surface; and,
an attraction plate fixed to the load plate and upon which the first force is exerted.
12. The pressure sensing assembly of claim 11 , wherein the displacement assembly is arranged to draw the attraction plate into contact with the tubing guide or the displacement assembly.
13. The pressure sensing assembly of claim 11 , wherein:
the displacement assembly includes a plurality of magnets; and,
the attraction plate is magnetic.
14. The pressure sensing assembly of claim 10 , further comprising a pusher assembly displaceable in the second direction to at least partially compress the tubing, wherein the load cell is arranged to detect:
the second force in response to the compression of the tubing by the pusher assembly; and,
a variation in the second force while the pusher assembly is at least partially compressing the tubing.
15. A pressure sensing assembly for an infusion pump, comprising:
a tubing guide arranged to receive tubing;
a displaceable load assembly at least partially disposed within the tubing guide and including:
a load plate arranged to contact the tubing; and,
an attraction plate fixed to the load plate and including a magnetic material;
a load cell; and,
a plurality of magnets, fixedly secured to the tubing guide and urging:
at least a portion of the attraction plate toward the tubing guide with a first force; and,
the load plate away from the load cell, wherein the load cell is arranged to detect a second force, greater than the first force, acting on the load plate counter to the first force.
16. A pressure sensing assembly for an infusion pump, comprising:
a tubing guide arranged to receive tubing;
a displaceable load assembly at least partially disposed within the tubing guide;
a load cell; and,
a displacement assembly engaged with the tubing guide and exerting a first force on the load assembly, wherein:
the first force draws at least a portion of the load assembly toward the tubing guide; and,
the load cell is arranged to detect a second force, greater than the first force, acting on the load assembly counter to the first force.
17. A method of measuring pressure in tubing for an infusion pump using a pressure sensing assembly including: tubing; a tubing guide; a displaceable load assembly with at least one first surface facing in a first direction; a load cell facing the load assembly in the first direction; and a displacement assembly engaged with the tubing guide, comprising:
disposing at least a portion of the tubing in the tubing guide;
exerting, using the displacement assembly, a first force on the load assembly;
drawing at least a portion of the load assembly toward the tubing guide with the first force; and,
detecting a second force, greater than the first force, acting on the load assembly counter to the first force.
18. The method of claim 1 , wherein:
the load assembly includes:
a load plate; and,
a magnetic attraction plate fixed to the load plate and including the at least one first surface; and,
the displacement assembly includes a plurality of magnets, the method further comprising generating the first force with the plurality of magnets.
19. The method of claim 17 , wherein the pressure sensing assembly includes a pusher assembly, the method further comprising:
displacing the pusher assembly in the second direction to assume a fixed position facing the load assembly in the second direction;
compressing the tubing with the pusher assembly; and,
detecting, using the load cell:
the second force in response to the disposition of the pusher assembly in the fixed position; and,
a variation in the second force with the pusher assembly in the fixed position.
20. A method of measuring pressure in tubing for an infusion pump using a pressure sensing assembly including: tubing; a tubing guide with at least one slot; tubing including a longitudinal axis; a displaceable load assembly; a load cell facing the longitudinal axis in a first direction; and a displacement assembly facing at least a portion of the load assembly in a second direction, opposite the first direction, the method comprising:
disposing at least a portion of the tubing in the at least one slot;
contacting a first surface of the load assembly with the tubing;
exerting, using the displacement assembly, a first force on the load assembly in the first direction;
displacing the load assembly, in response to a second force, greater than the first force, on the first surface, in the second direction; and,
detecting, using the load cell, the second force.
21. The method of claim 20 , wherein:
the load assembly includes:
a load plate including the first surface; and,
a magnetic attraction plate fixed to the load plate; and,
the displacement assembly includes a plurality of magnets, the method further comprising:
generating the first force with the plurality of magnets; and,
drawing the attraction plate into contact with the tubing guide or the plurality of magnets.
22. The method of claim 20 , wherein the pressure sensing assembly includes a pusher assembly, the method further comprising:
displacing the pusher assembly in the second direction;
at least partially compressing the tubing with the pusher assembly; and,
using the load cell to detect:
the second force in response to the compression of the tubing by the pusher assembly; and,
a variation in the second force while the pusher assembly is at least partially compressing the tubing.
23. A method of measuring pressure in tubing for an infusion pump using a pressure sensing assembly including: tubing; a tubing guide; a displaceable load assembly at least partially disposed within the tubing guide and including: a load plate arranged to contact the tubing and an attraction plate fixed to the load plate and including a magnetic material; a load cell; and a plurality of magnets, fixedly secured to the tubing guide, the method comprising:
disposing at least a portion of the tubing in the tubing guide;
generating a first force using the plurality of magnets;
drawing, with the first force:
at least a portion of the attraction plate toward the tubing guide; and,
the load plate away from the load cell; and,
detecting, using the load cell, a second force, greater than the first force, acting on the load plate counter to the first force.
24. A method of measuring pressure in tubing for an infusion pump using a pressure sensing assembly including: tubing; a tubing guide; a displaceable load assembly at least partially disposed within the tubing guide; a load cell; and a displacement assembly engaged with the tubing guide, the method comprising:
displacing at least a portion of the tubing in the tubing guide;
generating a first force with the displacement assembly;
drawing, using the first force, at least a portion of the load assembly toward the tubing guide; and,
detecting, using the load cell, a second force, greater than the first force, acting on the load assembly counter to the first force.