Abstract: A pneumatic oxygen conserving device uses a portion of gas exiting its main valve to interrupt delivery of the gas. Gas is dispensed upon inhalation and is interrupted by means of suitable pneumatic connections between the device's delivery system and its sensing system.

Abstract: A portable, cryogenic gas delivery apparatus includes a chamber which contains cryogenic material, such as oxygen, in both liquid and gas phases. A probe is mounted to move relative to the chamber in response to variations in pressure in the gas phase within the chamber. The probe has one part positioned within the chamber so that it is exposed to the pressure and temperature of the gas within the chamber and a second part located outside the chamber. The probe thus introduces heat from the ambient into the chamber. The probe preferably moves relative to the chamber in response to variations in pressure, moving away from the chamber to reduce the amount of thermal energy introduced into the chamber and toward the chamber to increase the amount of thermal energy introduced into the chamber. The apparatus includes a conserver which receives gas evaporating from the chamber and delivers it in efficient pulses to the end user in response to the user's inhalation.

Abstract: A pneumatic oxygen conserving device uses a portion of gas exiting its main value to interrupt delivery of the gas. Gas is dispensed upon inhalation and is interrupted by means of suitable pneumatic connections between the device's delivery system and its sensing system.

Abstract: A pneumatic oxygen conserving device includes a reservoir of pressurized gas delivered upon inhalation through a single-lumen cannula. Gas flow is interrupted by a series of interconnected passages and chambers, including a check valve which is acted upon by the flow of gas being delivered through the delivery outlet of the device. The device is self regulating to the extent that oxygen pulses of appropriate volume are delivered irrespective of the breathing rate of the user. The device includes a plate with various passages and chambers defined therein in such a way as to reduce the overall length of the device.

Abstract: A pneumatic oxygen conserving device includes a reservoir of pressurized gas delivered upon inhalation through a single-lumen cannula. Gas flow is interrupted by a series of interconnected passages and chambers, including a check valve which is acted upon by the flow of gas being delivered through the delivery outlet of the device. The device is self regulating to the extent that oxygen pulses of appropriate volume are delivered irrespective of the breathing rate of the user. The device includes a plate with various passages and chambers defined therein in such a way as to reduce the overall length of the device.