Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
  • A61M1/14—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
  • A61M1/16—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis with membranes
  • A61M1/1678—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis with membranes intracorporal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/18—TPC being performed according to specific parameters
  • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
  • H04W52/241—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters taking into account channel quality metrics, e.g. SIR, SNR, CIR or Eb/lo
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W52/00—Power management, e.g. Transmission Power Control [TPC] or power classes
  • H04W52/04—Transmission power control [TPC]
  • H04W52/18—TPC being performed according to specific parameters
  • H04W52/24—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters
  • H04W52/248—TPC being performed according to specific parameters using SIR [Signal to Interference Ratio] or other wireless path parameters where transmission power control commands are generated based on a path parameter
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
  • A61M1/14—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
  • A61M1/16—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis with membranes
  • A61M1/1698—Blood oxygenators with or without heat-exchangers

Definitions

• the present invention relates to methods and apparatus for adding oxygen to and removing carbon dioxide from blood in vivo without involving the patient's lungs.
• C02 carbon dioxide
• Another group of extracorporeal oxygenators employ gas permeable membranes. These devices take ⁇ many different shapes and configurations, however, the basic concept of operation is the same in all of these devices. Blood flows on one side of the gas permeable membranes while an an oxygen rich gas flows on the other side of the membrane. As the blood flows through the device, the oxygen travels across the gas permeable membrane and enters the blood. This allows oxygenation of the blood without actually introducing oxygen bubbles into the blood and without the corresponding need for an extensive defoaming apparatus.
• the present invention is directed to a novel apparatus and method for in vivo extrapulmonary oxygenation of blood.
• the apparatus and method of the present invention are designed for use on a routine basis and can be used without the necessity of major surgical procedures.
• the present invention can be used instead of the routine lung ventilation now used to treat patients with inadequate blood gas exchange.
• the apparatus of the present invention comprises a plurality of small diameter gas permeable tubes connected to headers at each end, and the headers- in turn are connected on one end to a source of oxygen rich gas and on the other end to an exhaust tube or other means for allowing the gas to flow out of the device.
• the apparatus is inserted into a patient's vena cava. An incision is made in the patient's jugular vein and a radiopaque guide catheter is inserted and is guided through the superior and inferior vena cava using a fluoroscope, so as to exit through an incision in the common femoral or iliac vein.
• the apparatus is then attached to the quide catheter exiting from the femoral or iliac vein and is pulled into the vena cava by withdrawing the guide catheter from the jugular vein.
• oxygen enriched gas is allowed to flow at relatively low pressure through the gas permeable tubes.
• Venous blood will flow around the small gas permeable tubes with oxygen passing from the tubes into the blood, causing blood oxygenation and carbon dioxide passing from the blood into the tubes and thence out of the body.
• the tubes are constructed of a material which allows oxygen and other gases to readily pass through their walls but which will not allow liquids, such as blood, to penetrate and whrch is also relatively nonthrombogenic.
• Figure 1 is a perspective view of one preferred embodiment of the apparatus of the present invention.
• Figure 2 is a cross-sectional view of the apparatus of Figure 1 along line 2-2.
• Figure 3 is a perspective view of an alternative preferred embodiment of the device of the present invention.
• Figure 4 is a cross-sectional view of the apparatus of Figure 3 along line 4-4.
• Figure 5 is a perspective view of the device illustrated in Figure 1 positioned within a patient's vena cavae, with a portion of the vena cavae broken away. »
• Figure 1 represents one preferred embodiment of the apparatus of the present invention which is generally designated at 10.
• the apparatus comprises a plurality of small, thin-walled, gas permeable tubes 12.
• the small tubes 12 are connected at each end to a header.
• the header at the base of the device is indicated at 14 and the header at the top of the device is indicated at 16.
• the gas permeable tubes 12 are designed and constructed so that molecule.- of oxygen and carbon dioxide are able to migrate across the tubing walls but at the same time the walls are impermeable to blood or other liquids and larger bubbles of gas. As discussed more thoroughly below, tubes 12 are also constructed of a relatively nonthrombogenic material.
• One currently favored material is a membrane of polyakylsulfone (PAS) approximately 2.5 to 4 microns thick imbedded on a porous tubular framework constructed of a material such as ethyl cellulose.
• Another preferred construction for tubes 12 comprises a layer of silicone rubber approxi- mately 25 microns thick placed on a similar porous tubular framework.
• tubes 12 of a microporous membrane using a material such as polypropylene, polytetrafluorethylene, or polyethylene, although those materials are believed somewhat less biocompatible than the materials dis ⁇ cussed above and may also allow the formation of undesirable microbubbles.
• a material such as polypropylene, polytetrafluorethylene, or polyethylene, although those materials are believed somewhat less biocompatible than the materials dis ⁇ cussed above and may also allow the formation of undesirable microbubbles.
• Other factors which may influence material selection include freedom from pinholes, fragility, commercial availability and cost.
• the tubes 12 are preferably spaced from one another so that blood may flow through the apparatus and around the walls of each tube, thus enhancing blood gas exchange through the walls of each tube.
• the ends of tubes 12 are firmly anchored in headers 14 and 16 by "potting" the tubes in a molded base 15 of silicon rubber or other biocompatible material. After the molded base 15 is cured, the end is cut away to leave the ends of tube 12 unobstructed to gas flow.
• the headers 14 and 16 are then bonded around each base 15 to form a gas tight seal so that oxygen bubbles cannot escape into the patient's vena cavae once the apparatus has been inserted therein.
• the configuration, length and diameter of the tubes 12 could vary according to the needs of each particular situation. However, it is the general goal in designing the device to maximize blood-membrane surface exposure and resultant oxygen-carbon dioxide transfer while minimizing the obstruction to normal blood flow.
• the currently preferred embodiment of the device includes about 30 tubes approximately 50 centi ⁇ meters (cm) in length and 1 millimeter (mm) in outside diameter. The entire apparatus is about 1.5 cm in diameter in the case of an adult. Such a configuration would expose about 468 cm 2 of gas permeable area to the flowing blood.
• the apparatus would include about 500 tubes approximately 250 cm in length and about 0.25 mm in outside diameter.
• the tubes 32 are intertwined as described more fully below. This configuration would result in about 9,750 cm 2 of gas permeable surface area, which is an increase of more than 20 times the gas permeable surface area of the preferred embodiment discussed above.
• the tubes could vary in diameter from about 0.25 mm to about 1 mm and that they could vary in length from about 50 cm to about 250 cm.
• the number of tubes used could also vary from 30 or less up to 500 or more.
• the result is that the gas transfer surface area can be varied from about 468 cm 2 to almost 10,000 cm 2 depend ⁇ ing on the specific requirements of the particular situation. Table 1 below summarizes some of the possible configurations of the apparatus including expected gas transfer rates.
• Figure 3 illustrates an apparatus using such a configuration.
• the apparatus is generally designated 30.
• this embodiment has a plurality of tubes 32 which are potted at the ends thereof and attached to headers.
• the header at the top of the device is designated 36 and the header at the base of the device is designated 34.
• the apparatus illustra ⁇ ted in Figure 3 is similar to the device illustrated in Figure 1. It is anticipated, for example, that both devices would use the same gas permeable materials for tubes 12 or 32 and both devices could use similar headers.
• Figure 4 is a cross-sectional view of the embodiment of the device shown in Figure 4. Sufficient space is provided between each of the tubes 32 to permit blood to flow freely between and around the tubes.
• FIG. 5 The superior vena cava and the inferior vena cava are labeled in Figure 5.
• the jugular vein 50 also labeled are the jugular vein 50, the diaphragm 52, the right ventricle of the heart (designated R.V.), the right a.-.rium (designated R.A. ) and the inguinal ligament 53.
• the patient's clavicle 54 also illustrated in Figure 4 are the patient's clavicle 54, the right subclavian vein 56, the innominate vein 58, the renal veins 64, the left common iliac vein 66, and the right external iliac vein 68.
• the apparatus 10 is inserted through an incision 18 into the right external iliac or right femoral vein 68.
• the apparatus is threaded or pulled through the superior and inferior vena cava by known means such as through the use of a radiopaque catheter and a fluoroscope (not shown), as discussed briefly above.
• the tubing 18 connected to header 14 will then enter the patient through incision 76 in the right external iliac or common femoral vein.
• the tubing 20 will then exit the patient through incision 72 in the right jugular vein 50.
• header 14 will be connected to a source of oxygen enriched gas through tubing 18 and header 16 will be connected to an exhaust means through tubing 20.
• the oxygen enriched gas will travel through header 14 into tubes 12 and upwardly until it reaches header 16 and travels out of the device.
• the gas will be able to permeate the tubes 12 and oxygenate the blood traveling through the vena cavae.
• carbon dioxide will be able to leave the blood and flow into tubes 12 and thereby be exhausted from the system.
• oxygen and carbon dioxide can readily trav l through the walls of tubes 12, blood can not enter the tubes. As a result, oxygenation can occur without the blood being directly exposed to gas bubbles.
• the gas entering tubes 12 may be 100% oxygen flowing at a rate of about 0.6 to 1.2 liters/minute. This will allow the device to operate at relatively low pressures within the range of 5-10 millimeters of mercury (mmHg) . Operation of the device at relatively low pressures will provide adequate blood oxygenation without a substantial risk of creating leaks or bubbles within the vena cavae.
• Figure 5 illus- trates the device in such a configuration.
• a rigid or semi ⁇ rigid stylet 22 which runs parallel to the tubes 12 and which is securely attached to headers 14 and 16.
• Stylet 22 may be formed of blood-compatible metal or plastic so that it may be bent to the desired configuration before inserting the device into the patient, thereby assuring than the apparatus will maintain an undulating or spiral configuration once in place.
• thrombosis formation In employing a device such as the device of the present invention it is critical to minimize thrombosis formation. Failure to adequately deal with this problem has been a factor in defeating prior attempts to artificially oxygenate blood. This problem may be dealt with by constructing the device using nonthrombo- genic materials. In the event that thrombosis forma- tion is still a problem it may be possible to coat the surface of the tubes 12 with an additional thrombo- resistant material or to treat the patient with platelet-sparing medications.
• the present device is a vast improvement over prior attempts to artificially oxygenate blood.
• the present device unlike routine treatments for lung diseases, allows the lungs to rest and recover from their ailment. It is also possible to use the present device for routine, temporary treatment.
• Prior blood oxygenators are principally used only during surgical procedures and are placed outside the body.
• the present device uses as its outer wall the vena cavae insitu. Blood is not flowed through artificial tubing or other devices. As a result, damage to the blood, including hemolysis and thrombosis formation, is minimized.
• the present invention provides for the efficient and relatively nontraumatic in vivo oxygenation of blood without involving the ailing lungs.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Heart & Thoracic Surgery (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Urology & Nephrology (AREA)
• Vascular Medicine (AREA)
• Emergency Medicine (AREA)
• Quality & Reliability (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• External Artificial Organs (AREA)

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Citations (12)

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• 1984
  • 1984-06-26 US US06/624,627 patent/US4583969A/en not_active Expired - Lifetime
• 1985
  • 1985-08-12 EP EP85904192A patent/EP0232260B1/en not_active Expired
  • 1985-08-12 JP JP60503672A patent/JPS62502591A/ja active Granted
  • 1985-08-12 WO PCT/US1985/001517 patent/WO1987001045A1/en active IP Right Grant
  • 1985-08-12 AT AT85904192T patent/ATE59561T1/de not_active IP Right Cessation
  • 1985-08-12 DE DE8585904192T patent/DE3581087D1/de not_active Expired - Fee Related

Patent Citations (12)

Non-Patent Citations (7)

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