Fluid feed pump, fluid circulation device, medical device and electronic device

Abstract

A fluid feed pump is configured, such that a fluid is fed from an outlet channel of the fluid feed pump through an outlet buffer chamber to a fluid channel. The outlet buffer chamber is designed to have a higher compliance than a compliance of a pump chamber. The driving period of the fluid feed pump is set to a shorter period than a time constant defined by the compliance of the pump chamber and a flow resistance between an inlet of the outlet channel and an outlet of the fluid channel. This enables the fluid to be fed with high efficiency by taking advantage of the pressure oscillation occurring between the pump chamber and the outlet buffer chamber.

1 . A fluid feed pump that feeds a fluid through a fluid channel, comprising:
 a pump chamber having variable volume;   an inlet channel arranged to allow inflow of the fluid from the fluid channel to the pump chamber;   a check valve provided between the inlet channel and the pump chamber;   an outlet channel connected with the pump chamber to feed the fluid out of the pump chamber; and   an outlet buffer chamber connected with the outlet channel to feed the fluid from the outlet channel to the fluid channel, wherein   the outlet buffer chamber has a compliance higher than a compliance of the pump chamber, and   a time per cycle of changing the volume of the pump chamber is shorter than a time constant defined by a product of the compliance of the pump chamber and a flow resistance between an inlet of the outlet channel and an outlet of the fluid channel.   
     
     
         2 . The fluid feed pump according to  claim 1 , wherein
 the outlet channel has a flow resistance lower than a flow resistance of the fluid channel.   
     
     
         3 . The fluid feed pump according to  claim 1 , wherein
 the compliance of the outlet buffer chamber is at least 10 times as high as the compliance of the pump chamber.   
     
     
         4 . The fluid feed pump according to  claim 1 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the fluid channel is connected with the inlet channel, so that the fluid fed from the outlet channel to the fluid channel is returned to the inlet buffer chamber.   
     
     
         5 . The fluid feed pump according to  claim 4 , wherein
 the inlet buffer chamber has a compliance that is at least five times as high as the compliance of the outlet buffer chamber.   
     
     
         6 . The fluid feed pump according to  claim 1 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the inlet buffer chamber is a deformable pack.   
     
     
         7 . The fluid feed pump according to  claim 1 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the inlet buffer chamber is a deformable pack to be attachable to and detachable from the fluid feed pump.   
     
     
         8 . The fluid feed pump according to  claim 1 , wherein
 the volume of the pump chamber is changed by actuation of a piezoelectric element.   
     
     
         9 . A fluid circulation device, comprising the fluid feed pump according to  claim 1 . 
     
     
         10 . A medical device, comprising the fluid feed pump according to  claim 1 . 
     
     
         11 . An electronic device, comprising the fluid feed pump according to  claim 1 . 
     
     
         12 . A fluid feed pump, comprising:
 a pump chamber having volume changeable by actuation of a piezoelectric element;   an outlet channel arranged to allow outflow of a fluid from the pump chamber to a fluid channel;   an inlet channel arranged to supply the fluid to the pump chamber; and   a check valve provided between the inlet channel and the pump chamber, wherein   the piezoelectric element is actuated in a shorter period than a time constant when internal pressure of the pump chamber increases and subsequently decreases,   the fluid feed pump further comprising:   an outlet buffer chamber provided between the outlet channel and the fluid channel and configured to have a compliance that is higher than a compliance of the pump chamber but is at most 100 times as high as the compliance of the pump chamber.   
     
     
         13 . The fluid feed pump according to  claim 12 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the fluid channel is connected with the inlet channel, so that the fluid fed from the outlet channel to the fluid channel is returned to the inlet buffer chamber.   
     
     
         14 . The fluid feed pump according to  claim 12 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the inlet buffer chamber has a compliance that is at least five times as high as the compliance of the outlet buffer chamber.   
     
     
         15 . The fluid feed pump according to  claim 12 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the inlet buffer chamber is a deformable pack.   
     
     
         16 . The fluid feed pump according to  claim 12 , further comprising:
 an inlet buffer chamber provided between the inlet channel and the check valve, wherein   the inlet buffer chamber is a deformable pack to be attachable to and detachable from the fluid feed pump.   
     
     
         17 . A fluid circulation device, comprising the fluid feed pump according to  claim 12 . 
     
     
         18 . A medical device, comprising the fluid feed pump according to  claim 12 . 
     
     
         19 . An electronic device, comprising the fluid feed pump according to  claim 12 .