Respiratory circuit terminal for a unilimb respiratory device

United States Patent [w]

Fukunaga et al.

US006003511A [ii] Patent Number: 6,003,511 [45] Date of Patent: *Dec. 21,1999

[54] RESPIRATORY CIRCUIT TERMINAL FOR A UNILIMB RESPIRATORY DEVICE

[75] Inventors: Atsuo F. Fukunaga; Blanca M.

Fukunaga, both of Rancho Palos
Verdes, Calif.

[73] Assignee: Medlis Corp., Rancho Palos Verdes,
Calif.

[ * ] Notice: This patent is subject to a terminal disclaimer.

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FOREIGN PATENT DOCUMENTS

93941 8/1923 Austria . WO/85 277 12/1985 WIPO .

OTHER PUBLICATIONS

Dorsch, Jerry A., M.D., Dorsch, Susan E., M.D., Understanding Anesthesia Equipment, Chapter 7, The Circle Absorption System, pp. 201-202 and 220-221.

Andrews, J. Jeffrey., Inhaled Anesthetic Delivery, Anesthesia, Fourth Edition, pp. 185; and 203-207.

Primary Examiner—John G. Weiss

Assistant Examiner—Joseph F. Weiss, Jr.

Attorney, Agent, or Firm—Bose McKinney & Evans LLP

[57] ABSTRACT

A method for providing assisted ventilation which avoids hypoxia and hypocapnia is disclosed, in which a predetermined dead space in an assisted ventilation system is provided external to the patient. The method may also be used to create normocapnia or moderate hypercapnia without causing hypoxia during assisted ventilation. Preferably, hypoxia can be avoided while inducing and/or maintaining the arterial carbon dioxide tension between about 35 and 95 mmHg. Dead space volumes as small as 10 ml and exceeding 150 ml are utilized in the method. An improved proximal terminal, tubular attachments, and coaxial filter are disclosed, which are safer the less expensive to use than prior art unilimb assisted ventilation systems; the devices of the present invention also reduce medical wastes in comparison to prior art assisted ventilation systems. An interface is provided, which incorporates the proximal terminal and other functional devices, to which tubular respiratory conduits of predetermined and/or adjustable dead space volumes can be connected.

20 Claims, 8 Drawing Sheets