Patents by Inventor Zbylut J. Twardowski

Zbylut J. Twardowski has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7695450
    Abstract: A catheter for hemodialysis comprises a flexible catheter tube defining a plurality of separate lumens. The catheter defines an arc angle of generally U-shape in its natural, unstressed configuration. Thus, the catheter may be implanted with a distal catheter portion residing in a vein of the patient, the distal catheter portion being of substantially the shape of the vein in its natural, unstressed condition. Also, a proximal catheter portion resides in a surgically created tunnel extending from the vein and through the skin of the patient, this section of the catheter also being typically in its natural, unstressed condition. Thus blood may be removed from the vein through one lumen of the catheter, and blood may be returned to the vein through another lumen of the catheter, while the catheter is subject to long term indwelling in the body.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: April 13, 2010
    Assignee: Curators of the University of Missouri, The University of Missouri
    Inventors: Zbylut J. Twardowski, John C. Van Stone, W. Kirt Nichols
  • Patent number: 6592565
    Abstract: The method of selecting and implanting a permanent venous catheter into a patient for use in chronic, extracorporeal blood treatment procedures. The method comprises determining the Body Surface Area of the patient. One then selects a permanent venous catheter having an actual length which is within 10% of a desired length as indicated in a Table found in this application for the Body Surface Area of the particular patient and a particular vein through which the catheter is to extend. Also, the internal diameter of the tubing is preferably adjusted in a manner correlating with the catheter length. Following catheter selection, the venous catheter is implanted in the venous system of the patient with the distal tip of the catheter being in or adjacent to the upper right atrium of the heart.
    Type: Grant
    Filed: April 26, 2001
    Date of Patent: July 15, 2003
    Inventor: Zbylut J. Twardowski
  • Publication number: 20030023198
    Abstract: The method of selecting and implanting a permanent venous catheter into a patient for use in chronic, extracorporeal blood treatment procedures. The method comprises determining the Body Surface Area of the patient. One then selects a permanent venous catheter having an actual length which is within 10% of a desired length as indicated in a Table found in this application for the Body Surface Area of the particular patient and a particular vein through which the catheter is to extend. Also, the internal diameter of the tubing is preferably adjusted in a manner correlating with the catheter length. Following catheter selection, the venous catheter is implanted in the venous system of the patient with the distal tip of the catheter being in or adjacent to the upper right atrium of the heart.
    Type: Application
    Filed: April 26, 2001
    Publication date: January 30, 2003
    Inventor: Zbylut J. Twardowski
  • Patent number: 6423050
    Abstract: A central-vein cathether is locked by anticoagulant and bactericidal solutions separated by an air bubble. The anticoagulant is injected first, then the air bubble, and then the bactericidal solution, so that the anticoagulant is located close to the catheter tip in contact with the blood and the bacterial solution is located close to the catheter hub, where bacteria contamination is common. The air bubble prevents mixing of the solutions. A multi-chamber syringe facilitates sequential injection of the anticoagulant, air and bactericidal agent with only one connection, decreasing chances of contamination. The syringe includes internal and external coaxial barrels separated by seals, the external barrel having a discharge opening located off center in the barrel bottom, and the internal barrel having two or three chambers, each with an outlet opening.
    Type: Grant
    Filed: June 16, 2000
    Date of Patent: July 23, 2002
    Inventor: Zbylut J. Twardowski
  • Patent number: 6146536
    Abstract: A hemodialyzer apparatus comprises a reusable dialyzer membrane as well as reusable blood flow path and dialysis flow path units. The apparatus automatically primes itself and makes dialysis solution from dry chemicals, concentrates, and fresh water which is provided to the apparatus. Also, after use, the apparatus automatically prepares cleaning and rinsing solution for the cleaning and rinsing of the dialyzer membrane as well as the dialyzate and blood flow path means, to provide a system which is so simplified in terms of automatic operation that it may be usable for daily dialysis at home.
    Type: Grant
    Filed: April 12, 1999
    Date of Patent: November 14, 2000
    Inventor: Zbylut J. Twardowski
  • Patent number: 6132616
    Abstract: A method for flushing and filling of an extracorporeal blood circulation system of a dialysis machine is disclosed. The machine has a dialyzer, a separate dialysis liquid circuit flowing through a dialysate side of the dialyzer with the extracorporeal blood circulation system flowing through a blood side of the dialyzer for removal of impurities from the blood and the dialysate and blood sides of the dialyzer separated by a hemodialyzer membrane. The method comprises the steps of transporting dialysis liquid from the dialysis liquid circuit in the dialysate side of the dialyzer through the hemodialyzer membrane into the blood side of the dialyzer and the extracorporeal blood circulation system to flush and fill the system and conducting a dialysis treatment.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: October 17, 2000
    Inventors: Zbylut J. Twardowski, Rodney S. Kenley
  • Patent number: 5961486
    Abstract: Blood is circulated through a multiple lumen catheter which connects between a vein of a patient and the blood treatment device. The catheter and the lumens thereof each define distal ends which are positioned within the vein. By this invention, one withdraws blood from the vein through one of the lumens at a flow rate of at least about 200 ml./min. while also inserting blood into the vein through another of said lumens at a similar flow rate. The distal ends of the lumens are longitudinally spaced from each other by no more than about 5 mm. It has been found that the following advantages can be achieved by this method: less clot formation coupled with low direct blood recirculation and longer catheter survival. Also, the catheter of this invention works well in either direction of blood flow through the respective lumens.
    Type: Grant
    Filed: November 5, 1998
    Date of Patent: October 5, 1999
    Inventors: Zbylut J. Twardowski, W. Kirt Nichols, John C. Van Stone
  • Patent number: 5902476
    Abstract: A hemodialyzer apparatus comprises a reusable dialyzer membrane as well as reusable blood flow path and dialysis flow path units. The apparatus automatically primes itself and makes dialysis solution from dry chemicals, concentrates, and fresh water which is provided to the apparatus. Also, after use, the apparatus automatically prepares cleaning and rinsing solution for the cleaning and rinsing of the dialyzer membrane as well as the dialyzate and blood flow path means, to provide a system which is so simplified in terms of automatic operation that it may be usable for daily dialysis at home.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: May 11, 1999
    Inventor: Zbylut J. Twardowski
  • Patent number: 5685867
    Abstract: Blood is circulated through a multiple lumen catheter which connects between a vein of a patient and the blood treatment device. The catheter and the lumens thereof each define distal ends which are positioned within the vein. By this invention, one withdraws blood from the vein through one of the lumens at a flow rate of at least about 200 ml./min. while also inserting blood into the vein through another of said lumens at a similar flow rate. The distal ends of the lumens are longitudinally spaced from each other by no more than about 5 mm. It have been found that the following advantages can be achieved by this method: less clot formation coupled with low direct blood recirculation and longer catheter survival. Also, the catheter works well in either direction of blood flow through the respective lumens.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 11, 1997
    Assignee: The Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, W. Kirt Nichols, John C. Van Stone
  • Patent number: 5569182
    Abstract: Blood is circulated through a multiple lumen catheter which connects between a vein of a patient and the blood treatment device. The catheter and the lumens thereof each define distal ends which are positioned within the vein. By this invention, one withdraws blood from the vein through one of the lumens at a flow rate of at least about 200 ml./min. while also inserting blood into the vein through another of said lumens at a similar flow rate. The distal ends of the lumens are longitudinally spaced from each other by no more than about 5 mm. It have been found that the following advantages can be achieved by this method: less clot formation coupled with low direct blood recirculation and longer catheter survival. Also, the catheter works well in either direction of blood flow through the respective lumens.
    Type: Grant
    Filed: February 9, 1995
    Date of Patent: October 29, 1996
    Assignee: The Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, W. Kirt Nichols, John C. Van Stone
  • Patent number: 5509897
    Abstract: A catheter for hemodialysis comprises a flexible catheter tube defining a plurality of separate lumens. The catheter defines an arc angle of generally U-shape in its natural, unstressed configuration. Thus, the catheter may be implanted with a distal catheter portion residing in a vein of the patient, the distal catheter portion being of substantially the shape of the vein in its natural, unstressed condition. Also, a proximal catheter portion resides in a surgically created tunnel extending from the vein and through the skin of the patient, this section of the Catheter also being typically in its natural, unstressed condition. Thus blood may be removed from the vein through one lumen of the catheter, and blood may be returned to the vein through another lumen of the catheter, while the catheter is subject to long term indwelling in the body.
    Type: Grant
    Filed: February 15, 1995
    Date of Patent: April 23, 1996
    Assignee: The Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, John C. Van Stone, W. Kirt Nichols
  • Patent number: 5484397
    Abstract: A hemodialyzer apparatus comprises a reusable dialyzer membrane as well as reusable blood flow path and dialysis flow path units. The apparatus automatically primes itself and makes dialysis solution from dry chemicals, concentrates, and fresh water which is provided to the apparatus. Also, after use, the apparatus automatically prepares cleaning and rinsing solution for the cleaning and rinsing of the dialyzer membrane as well as the dialyzate and blood flow path means, to provide a system which is so simplified in terms of automatic operation that it may be usable for daily dialysis at home.
    Type: Grant
    Filed: November 22, 1993
    Date of Patent: January 16, 1996
    Inventor: Zbylut J. Twardowski
  • Patent number: 5405320
    Abstract: A catheter for hemodialysis comprises a flexible catheter tube defining a plurality of separate lumens. The catheter defines an arc angle of generally U-shape in its natural, unstressed configuration. Thus, the catheter may be implanted with a distal catheter portion residing in a vein of the patient, the distal catheter portion being of substantially the shape of the vein in its natural, unstressed condition. Also, a proximal catheter portion resides in a surgically created tunnel extending from the vein and through the skin of the patient, this section of the catheter also being typically in its natural, unstressed condition. Thus blood may be removed from the vein through one lumen of the catheter, and blood may be returned to the vein through another lumen of the catheter, while the catheter is subject to long term indwelling in the body.
    Type: Grant
    Filed: April 8, 1993
    Date of Patent: April 11, 1995
    Assignee: The Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, John C. Van Stone, W. Kirt Nichols
  • Patent number: 5336165
    Abstract: A hemodialyzer apparatus comprises a reusable dialyzer membrane as well as reusable blood flow path and dialysis flow path units. The apparatus automatically primes itself and makes dialysis solution from dry chemicals, concentrates, and fresh water which is provided to the apparatus. Also, after use, the apparatus automatically prepares cleaning and rinsing solution for the cleaning and rinsing of the dialyzer membrane as well as the dialyzate and blood flow path means, to provide a system which is so simplified in terms of automatic operation that it may be usable for daily dialysis at home.
    Type: Grant
    Filed: August 21, 1991
    Date of Patent: August 9, 1994
    Inventor: Zbylut J. Twardowski
  • Patent number: 5209723
    Abstract: A multiple lumen, intravenous catheter for hemodialysis or the like defines a distal end portion in which at least a pair of the catheter lumens each communicates with the exterior through aperture means. By this invention the aperture means of one of the lumens defines a first port at essentially the distal catheter end, and the aperture means of the other of the lumens defines a second port spaced proximally along the catheter from the distal end and first port. The second port is positioned to face radially inwardly to at least a slight degree to avoid engagement of the wall of the blood vessel that the catheter occupies. Additionally, the tip of the catheter distal of the second port is preferably of substantially helically shape, being sized to assist in keeping the second port away from the blood vessel wall. As another feature, the catheter may be angled in its as-manufactured, unstressed condition to avoid pressing by elastic memory against internal blood vessel walls.
    Type: Grant
    Filed: October 8, 1991
    Date of Patent: May 11, 1993
    Assignee: The Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, John C. Van Stone, W. Kirt Nichols
  • Patent number: 5171227
    Abstract: A peritoneal dialysis catheter comprises a distal tubular section and a proximal tubular section, connected together by a nonintegral tubular connector so that the respective sections are connected together in sealed flow relation. Such a catheter may be surgically implanted in the peritoneal cavity, extending to the chest of the patient with an end thereof protruding from the chest. The respective ends of the catheter section may be connected to each other through the tubular connector as the tubular sections are surgically implanted, and typically after such implantation is substantially complete.
    Type: Grant
    Filed: April 16, 1991
    Date of Patent: December 15, 1992
    Assignee: The Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, Ramesh Khanna, W. Kirt Nichols, Karl D. Nolph
  • Patent number: 4772269
    Abstract: A peritoneal catheter comprises a flexible catheter tube carrying porous cuff means to facilitate permanent securance of the catheter to the abdominal wall. The catheter tube defines, in its natural, unstressed condition, a bent segment adjacent the porous cuff means. This permits the catheter to be mounted in a tunnel formed through the abdominal wall in relatively unstressed configuration with both ends pointing downwardly.
    Type: Grant
    Filed: February 11, 1987
    Date of Patent: September 20, 1988
    Assignee: Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, Karl D. Nolph
  • Patent number: 4687471
    Abstract: A peritoneal catheter comprises a flexible catheter tube carrying porous cuff means to facilitate permanent securance of the catheter to the abdominal wall. The catheter tube defines, in its natural, unstressed condition, a bent segment adjacent the porous cuff means. This permits the catheter to be mounted in a tunnel formed through the abdominal wall in relatively unstressed configuration, with both ends pointing downwardly toward the feet of the patient. In one embodiment, the catheter includes a flange extending circumferentially outwardly of the catheter tube adjacent to the porous cuff means. The flange extends at a nonperpendicular angle relative to the axis of the catheter tube, and the slope of the flange extends transverse the direction of the bent segment. The angled flange, when sutured to the posterior rectus sheath, maintains the catheter tube in the desired tunnel direction within the abdominal wall, with the distal end of the catheter tube pointed properly downwardly toward the pelvic cavity.
    Type: Grant
    Filed: February 6, 1986
    Date of Patent: August 18, 1987
    Assignee: Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, Karl D. Nolph, Ramesh Khanna
  • Patent number: 4604379
    Abstract: Peritoneal dialysis solution may have an osmotic agent as a partial or complete substitute to the conventional dextrose. The osmotic agent is gelatin chemically cross-linked to suppress gelation.
    Type: Grant
    Filed: June 18, 1984
    Date of Patent: August 5, 1986
    Assignee: Curators of the University of Missouri
    Inventors: Zbylut J. Twardowski, Karl D. Nolph