System and method for drug preparation and delivery
A disposable cassette for mixing a drug in a vial includes a liquid inlet for connection to a liquid supply, a first vial spike, a second vial spike, a chamber and a valve mechanism. The chamber, the first and second vial spikes, and the liquid inlet are in fluid communication with each other. The valve mechanism may be actuated to control flow between the chamber, the vial receptacles and the liquid inlet.
1. A method of adjusting the pressure within a container, the container in valved fluid communication with a variable volume chamber through a container port, the variable volume chamber defined by a rigid chamber wall and a membrane, the membrane capable of being moved toward or away from the rigid chamber wall under the influence of positive or negative pressure, the method comprising:
closing a container port valve fluidly connecting the chamber with the container port fluidly connecting the container to the container port,
measuring a first pressure associated with the chamber
opening the container port valve
measuring a second pressure associated with the chamber
moving the membrane away from the rigid chamber wall to decrease the pressure in the container, or moving the membrane toward the rigid chamber wall to increase the pressure in the container.
2. A method according to claim 1 , wherein the pressure in the container is decreased by removing a gas from the container.
3. A method according to claim 2 , wherein the variable volume chamber is in fluid communication with a venting port through a venting port valve, and wherein the method further comprises removing gas from the container by moving gas from the container to the variable volume chamber as the membrane moves away from the rigid chamber wall, closing the container port valve, opening the venting port valve, and moving the membrane toward the rigid chamber wall.
4. A method according to claim 3 , wherein the first and second pressures are measured by a pressure transducer and transmitted to a controller, and wherein the controller controls the container port valve, the venting port valve, and movement of the membrane based on a comparison by the controller of the first pressure with the second pressure.
5. A method according to claim 4 , wherein the second pressure is greater than the first pressure.
6. A method according to claim 2 , wherein the gas is air.
7. A method according to claim 1 , wherein the pressure in the container is increased by introducing a gas into the container.
8. A method according to claim 7 , wherein the variable volume chamber is in fluid communication with a venting port through a venting port valve, the venting port being in fluid communication with a source of gas, and wherein the method further comprises closing the container port valve, opening the venting port valve, moving the membrane away from the rigid chamber wall to introduce the gas into the variable volume chamber, closing the venting port valve, opening the container port valve, and moving the membrane toward the rigid chamber wall.
9. A method according to claim 8 , wherein the first and second pressures are measured by a pressure transducer and transmitted to a controller, and wherein the controller controls the container port valve, the venting port valve, and movement of the membrane based on a comparison by the controller of the first pressure with the second pressure.
10. A method according to claim 9 , wherein the second pressure is less than the first pressure.
11. A method according to claim 6 , wherein the gas is air.
12. A system for adjusting the pressure within a container comprising:
a variable volume chamber defined by a rigid chamber wall and a membrane, the membrane capable of being moved toward or away from the rigid chamber wall under the influence of positive or negative pressure;
a container port in fluid communication with the variable volume chamber through a container port valve;
a pressure transducer configured to measure the pressure associated with the variable volume chamber;
a controller configured to receive pressure information from the pressure transducer, and to control the container port valve and movement of the membrane, wherein the container can be fluidly connected to the container port valve, and the controller is configured to:
determine a first pressure of the variable volume chamber with the container port valve closed,
determine a second pressure of the variable volume chamber with the container port valve open,
open the container port valve, and
control movement of the membrane toward or away from the rigid chamber wall to increase or decrease the pressure within the container.
13. The system of claim 12 , further comprising a venting port in fluid communication with the variable volume chamber through a venting port valve, wherein the controller is configured to decrease pressure in the container by:
opening the container port valve,
moving the membrane away from the rigid chamber wall,
removing a gas from the container into the variable volume chamber,
closing the container port valve,
opening the venting port valve, and
moving the membrane toward the rigid chamber wall.
14. The system of claim 13 , wherein the controller is configured to decrease the pressure in the container if the first pressure is less than the second pressure.
15. The system of claim 13 , wherein the venting port is in fluid communication with a gas at ambient pressure, and wherein the controller is configured to control the venting port valve to equalize the first pressure with gas pressure at the venting port.
16. The system of claim 13 , wherein the gas is air.
17. The system of claim 12 , further comprising a venting port in fluid communication with the variable volume chamber through a venting port valve, wherein the controller is configured to increase pressure in the container by:
closing the container port valve,
opening the venting port valve,
moving the membrane away from the rigid chamber wall to introduce a gas through the venting port into the variable volume chamber,
closing the venting port valve,
opening the container port valve, and
moving the membrane toward the rigid chamber wall.
18. The system of claim 17 , wherein the controller is configured to increase pressure in the container if the first pressure is greater than the second pressure.
19. The system of claim 17 , wherein the venting port is in fluid communication with a gas at ambient pressure, and wherein the controller is configured to control the venting port valve to equalize the first pressure with gas pressure at the venting port.
20. The system of claim 17 , wherein the gas is air.