Dual Latching Microvalves

Abstract

A valve for use in connection with microfluidic devices includes a safety feature such that flow is controlled even in the case of a loss of power, thus having applications in critical applications such as the precise delivery of drugs over time. The valve may be used in connection with multiple tubes delivering drugs, and may be used with a pump, such as an electrochemical pump, to provide the force to move the fluids containing drugs for delivery. In certain applications, more than one medicine may be delivered and metered independently using a single pump with multiple reservoirs and valves.

1 . A valve mechanism for delivering a first drug to a patient, comprising:
 a. a first dual latching valve;   b. a second dual latching valve; and   c. a dual sided pump fluidically connected to the first dual latching valve and second dual latching valve for near-continuous delivery of the first drug to the patient.   
     
     
         2 . The valve mechanism of  claim 1 , further comprising a first drug reservoir fluidically connected to the dual sided pump, wherein the mechanism is configured by placement of the first dual latching valve and second dual latching valve such that there is never a direct fluidic path from the first drug reservoir to the patient. 
     
     
         3 . The valve mechanism of  claim 2 , wherein the first dual latching valve and second dual latching valve are configured to provide intermittent delivery of multiple doses of the first drug to a patient. 
     
     
         4 . The valve mechanism of  claim 2 , further comprising a second reservoir for holding a second drug, wherein the second reservoir is fluidically connected to the dual sided pump, and wherein the first dual latching valve and second dual latching valve are configured to control independent delivery of the first drug and the second drug to the patient. 
     
     
         5 . The valve mechanism of  claim 4 , wherein the first dual latching valve and second dual latching valve are configured to deliver multiple doses of the first drug from the first reservoir to the patient with fewer or no doses of the second drug from the second reservoir to the patient. 
     
     
         6 . The valve mechanism of  claim 4 , wherein the first dual latching valve and second dual latching valve are configured to create a mixing action between the first reservoir and the second reservoir. 
     
     
         7 . The valve mechanism of  claim 4 , wherein the dual sided pump is an electrochemical pump. 
     
     
         8 . The valve mechanism of  claim 4 , wherein the first dual latching valve and second dual latching valve are connected through an actuation mechanism such that both the first dual latching valve and second dual latching valve cannot be open simultaneously. 
     
     
         9 . The valve mechanism of  claim 8 , wherin the actuation mechanism comprises a cam or a ratchet to open the first dual latching valve and close the second dual latching valve in a first position, and to close the first dual latching valve and open the second dual latching valve in a second position, as the cam or ratchet rotates around an axis. 
     
     
         10 . A dual latching cam microvalve, comprising:
 a. a first valve arm;   b. a first compressible tube adjacent to the first valve arm;   c. a first valve seat adjacent to the first tube to form, together with the first valve arm and the first tube, a first valve;   d. a second valve arm;   e. a second compressible tube adjacent to the second valve arm;   f. a second valve seat adjacent to the second tube to form, together with the second valve arm and the second tube, a second valve;   g. a cam positioned to rotate around an axis between a first position and a second position, wherein rotation of the cam to the first position engages the second valve arm end to close the second tube and allow the first tube to open, and rotation of the cam to the second position engages the first valve arm end to close the first tube and allow the second tube to open, such that both tubes are never open at the same time;   h. one or more actuation mechanisms attached to the cam to rotate the cam between the first and second position; and   i. at least one electrical power source electrically connected to the at least one actuation mechanism.   
     
     
         11 . The dual latching cam microvalve of  claim 10 , further comprising:
 a. a first resilient member engaged with the first valve arm to bias the first valve arm end towards the first valve seat; and   b. a second resilient member engaged with the second valve arm to bias the second valve arm end towards the second valve seat.   
     
     
         12 . The dual latching cam microvalve of  claim 10 , further comprising:
 a. a first resilient member engaged with the first valve arm to bias the first valve arm end away from the first valve seat; and   b. a second resilient member engaged with the first valve arm to bias the second valve arm end away from the second valve seat.   
     
     
         13 . The dual latching cam microvalve of  claim 11 , wherein the first and second resilient members comprise one or more springs. 
     
     
         14 . The dual latching cam microvalve of  claim 12 , wherein the first and second resilient members comprise one or more springs. 
     
     
         15 . The dual latching cam microvalve of  claim 10 , wherein the one or more actuation mechanisms are selected from the set consisting of shape memory alloy wires, a solenoid, a motor, a pneumatic actuator, and a hydraulic actuator. 
     
     
         16 . The dual latching cam microvalve of  claim 10 , further comprising at least one additional valve arm controlled by a cam shaped to start and stop a fluid movement through more than one fluidic pathway in a coordinated manner. 
     
     
         17 . The dual latching cam microvalve of  claim 10 , wherein both the first valve and second valve are applied to a single flow path through the first and second tubes wherein one of the first and second valves must be closed when the other of the first and second valves is open. 
     
     
         18 . The dual latching cam microvalve of  claim 17 , further comprising:
 a. a reservoir for holding a fluid; and   b. a dosing chamber fluidically connected to a reservoir by the first tube, wherein when the first valve is open and the second valve is closed, the fluid is drawn from the reservoir to a dosing chamber, and when the second valve is open and the first valve is closed, the fluid is pushed from the dosing chamber into a patient.   
     
     
         19 . The dual latching cam microvalve of  claim 18 , wherein the fluid comprises a drug, and wherein a maximum volume of the dosing chamber is sized to accommodate a medically efficacious quantity of the drug being delivered to the patient. 
     
     
         20 . The dual latching cam microvalve of  claim 19 , wherein delivery of the drug from the dosing chamber is timed based on an input signal. 
     
     
         21 . A valve mechanism for delivering a first drug and a second drug to a patient, comprising:
 a. a first dual latching cam microvalve;   b. a second dual latching cam microvalve;   c. a dual-sided pump fluidically connected to the first dual latching cam microvalve and second dual latching cam microvalve for independent delivery of either the first or second drugs to the patient;   d. a first drug reservoir fluidically connected to the first dual latching cam microvalve and a first side of the dual-sided pump; and   e. a second drug reservoir fluidically connected to the second dual latching cam microvalve and a second side of the dual-sided pump.   
     
     
         22 . The valve mechanism of  claim 21 , wherein the first drug and second drug are the same. 
     
     
         23 . The valve mechanism of  claim 21 , wherein the first drug and second drug are different. 
     
     
         24 . The valve mechanism of  claim 21 , wherein the first dual latching cam microvalve and second dual latching cam microvalve are configured to deliver multiple doses of the first drug from the first reservoir to the patient and to deliver fewer or no doses of the second drug from the second reservoir. 
     
     
         25 . The valve mechanism of  claim 21 , wherein the dual-sided pump is an electrochemical pump. 
     
     
         26 . The valve mechanism of  claim 21 , wherein the first dual latching cam microvalve and the second dual latching cam microvalve are connected through an actuation mechanism such that both the first dual latching cam microvalve and the second dual latching cam microvalve cannot be open to the patient simultaneously.