Hand-held, low-flow therapeutic gas dispensers

Abstract

A hand-held, low-flow dispenser comprises an enclosure holding a gas cartridge. A spring-biased needle is advanced to puncture a septum on the gas cartridge, and a separate spring-biased ball valve is used to turn the resulting gas flow off and on as well as to control the flow rate.

1 . A hand-held, low-flow gas dispenser comprising:
 an enclosure having a gas outlet;   a pressurized gas cartridge having a penetrable septum within the enclosure;   a pin having a tip for penetrating the septum;   a pin carrier adapted to advance the pin through the septum to form a hole and to retract the pin from the hole to allow gas flow from the cartridge, wherein the pin is prevented from reentering the hole; and   a flow control valve in series with but separate from the pin and pin carrier for selectively controlling the flow rate of gas released from the cartridge.   
   
   
       2 . A dispenser as in  claim 1 , wherein the pin carrier comprises a bistable mechanism which is shifted from an advanced configuration to a retracted configuration after the carrier advances a predetermined distance. 
   
   
       3 . A dispenser as in  claim 2 , wherein the bistable mechanism comprises a spring. 
   
   
       4 . A dispenser as in  claim 1 , wherein the pressurized gas cartridge is removably disposed in the enclosure. 
   
   
       5 . A dispenser as in  claim 1 , wherein the pressurized gas cartridge is non-removably disposed in the enclosure. 
   
   
       6 . A dispenser as in  claim 1 , wherein the pin has a solid core. 
   
   
       7 . A dispenser as in  claim 6 , wherein the pin has a width in the range from 0.5 mm to 2 mm. 
   
   
       8 . A dispenser as in  claim 1 , wherein the pin carrier comprises a bistable spring having an advanced configuration and a retractable configuration. 
   
   
       9 . A dispenser as in  claim 1 , wherein the flow control valve comprises a spring-loaded ball valve with a rotatable stem for opening the valve against the spring. 
   
   
       10 . A dispenser as in  claim 9 , wherein the flow control valve is calibrated to deliver gas at a flow rate in the range from 1 cc/sec to 50 cc/sec 
   
   
       11 . A dispenser as in  claim 9 , wherein the flow control valve is located in the enclosure between the gas cartridge and the outlet. 
   
   
       12 . A dispenser as in  claim 9 , wherein the flow control valve is located in a neck of the gas cartridge. 
   
   
       13 . A dispenser as in  claim 1 , wherein the outlet is adapted to seal against a nostril. 
   
   
       14 . A dispenser as in  claim 1 , further comprising means for redirecting away from the gas outlet gas flow in the event of overpressure of the gas cartridge. 
   
   
       15 . A dispenser as in  claim 14 , wherein the means comprises a failure weld in a component exposed to pressure from the gas cartridge when the flow control valve is closed. 
   
   
       16 . A dispenser as in  claim 14 , comprising a gasket between the gas cylinder and the enclosure, wherein the gasket extrudes in response to overpressure when the flow control valve is closed. 
   
   
       17 . A dispenser as in  claim 14 , comprising an O-ring above the flow control valve which fails in response to overpressure when the flow control valve is open. 
   
   
       18 . A method for dispensing low-flow rate gas from a hand-held dispenser, said method comprising:
 penetrating a pin through a septum on a gas cartridge in the dispenser to create a hole;   retracting the pin from the hole to permit gas flow through the hole to an outlet on the dispenser, wherein the pin is prevented from reentering the hole; and   adjusting a separate valve on the dispenser to control the flow rate of the gas through an outlet on the dispenser.   
   
   
       19 . A method as in  claim 18 , wherein the pin is mounted on a pin carrier which shifts from an advanced configuration to a retracted configuration as the pin or carrier engages a stop in the dispenser. 
   
   
       20 . A method as in  claim 19 , wherein the carrier comprises a bistable spring which springs from the advanced to retracted configurations. 
   
   
       21 . A method as in  claim 18 , wherein the gas is a therapeutic gas. 
   
   
       22 . A method as in  claim 21 , wherein the therapeutic gas comprises carbon dioxide. 
   
   
       23 . A method as in  claim 22 , wherein the gas comprises at least 50% carbon dioxide by volume. 
   
   
       24 . A method as in  claim 18 , wherein the valve is adjusted to control flow at a rate from 1 cc/sec to 50 cc/sec 
   
   
       25 . A method as in  claim 18 , wherein adjusting comprises a rotating nose piece which adjusts the position of a spring-loaded ball valve. 
   
   
       26 . A method as in  claim 18 , wherein the spring-loaded ball valve is disposed between the gas cartridge and the outlet. 
   
   
       27 . A method as in  claim 18 , wherein the spring-loaded ball valve is disposed in the cartridge. 
   
   
       28 . A method as in  claim 18 , further comprising redirecting gas flow away from the gas outlet in the event of overpressure of the gas cartridge. 
   
   
       29 . A method as in  claim 28 , wherein redirecting comprises at least one of ring failure, gasket failure, and component weld failure. 
   
   
       30 . A method for manufacturing a low-flow rate gas dispenser, said method comprising:
 providing an enclosure having an outlet, a septum-penetrating pin, and a control valve stem;   providing a gas cartridge having a penetrable septum and a spring-loaded valve; and   assembling the gas cartridge and the enclosure so that the pin is located adjacent the septum and the control valve stem can engage the spring-loaded valve after the septum has been penetrated.