Title:
【発明の名称】複数の実質的に同一の呼吸を届けるベンチレータ
Document Type and Number:
Japanese Patent JP3058881
Kind Code:
B2
Abstract:
A valve (42) in a medical ventilator (30) which controls the flow of gas from a pressurized gas source (32) to a patient for inhalation. Flow through the valve is choked and pressure upstream of the valve is held stable so that a known relationship exists between the position of the valve and the flow rate through the valve. An open loop control system (44,46) causes the valve to open or close as needed to deliver a preselected tidal volume of gas to the patient on each breath. Since the flow rate is known, no feedback to the controller regarding actual flow conditions is required. The exact positioning of the valve and length of time that the valve is to be held open is predetermined by the controller before the breath is delivered, and is repeated for subsequent breaths. Preferably, the valve is driven by a stepper motor (74) and the controller comprises a microcomputer. The controller compensates for ramping of the stepper motor as the valve opens and closes in determining the positions of the valve required to deliver the preselected tidal volume. To ensure precise engagement between a valve member (72) and a valve seat (62), the valve member is mounted on a flexible, linear wire (88). Additionally, a spirally wound spring (94) surrounds a stepper motor shaft (76) and biases the shaft so as to close the valve in the event of a power loss.
Inventors:
Douglas F. Debreeze
Lyndon A. Baker
Lyndon A. Baker
Application Number:
JP28027087A
Publication Date:
July 04, 2000
Filing Date:
November 04, 1987
Export Citation:
Assignee:
Bird Products Corporation
International Classes:
F16K1/36; A61M16/00; A61M16/20; A62B9/02; F16K31/44; F16K39/02; A61M16/12; (IPC1-7): A61M16/00
Domestic Patent References:
| JP5191819U | ||||
| JP56500199A |
Foreign References:
| US4617637A |
Other References:
【文献】米国特許4527557(US,A)
Attorney, Agent or Firm:
Hisaro Fukami (1 person outside)