Cheng Lin Ji

US Patent:

58885463, Mar 30, 1999

Filed:

Aug 28, 1995

Appl. No.:

8/519738

Inventors:

Cheng Ji - Los Angeles CA
Guido Guglielmi - Santa Monica CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61K 910

US Classification:

424484

Abstract:

A multipurpose ointment (MPOc) in a semisolid-semiliquid form and a multipurpose particle (MPPc) in a solid soft particulate form are prepared by combining a matrix base in a aqueous solution with a liquid oil base and added modifiers and medications to form either an ointment or suspension of particles for endovascular disposition for embolizing abnormal microvascular beds or nidi. The ointment or particles are formed from a albumin (human serum or chicken egg) matrix or equivalent material or combination of the same in an aqueous solution, typically contrast-medium solution, which has been emulsified with a radiopaque oil base such as ETHIODOL, and then heated to modify the mobility, viscosity, deformability, elasticity, surface tension and friction along with the inclusion of medications and modifiers for the desired physical characteristics and biological end effects.

US Patent:

60119950, Jan 4, 2000

Filed:

Dec 29, 1997

Appl. No.:

8/998589

Inventors:

Guido Guglielmi - Santa Monica CA
Cheng Ji - Los Angeles CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61B 1738

US Classification:

607 99

Abstract:

Hyperthermic treatment of tissue such as cancer tumors, is realized by providing an ohmic heating element on the distal tip of a catheter endovascularly inserted upstream of the tissue. Electrical power is provided to the element for a selected time and degree to raise the temperature of blood to a thermally mediating level such as 42. degree. C. , but not to heat the blood so that distal tissues downstream are adversely affected. The element comprises a helical coil heater disposed proximate to the end of a catheter and within an expandable cage. The cage can be selectively deployed by expanding it to maintain the coil out of contact with the vessel walls while still allowing free blood flow. Alternatively a guidewire within an expandable cage can be disposed within the same catheter wherein the heating coil has been wound onto the guidewire or the guidewire is uninsulated at that portion within the cage serves as an electrode to directly heat the blood. Angioplasty without blood flow blockage is realized by expanding a cage instead of a balloon on the catheter.

US Patent:

58512063, Dec 22, 1998

Filed:

Jun 30, 1995

Appl. No.:

8/497294

Inventors:

Guido Guglielmi - Santa Monica CA
Cheng Ji - Los Angeles CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61B 1739

US Classification:

606 28

Abstract:

A trombus is generated in an aneurysm, arteriovenous malformation or fistula by means of a catheter having an insulated heating coil coupled to an insulated delivery wire. In one embodiment, two delivery wires are coupled to heating coils to provide a closed circuit. The heating coils may be in the form of a double helix or a single helix in combination with a straight heating coil. The heating coils may be electrolytically or mechanically detached therefrom. Alternatively, a single insulated heating coil may be attached to a single insulated delivery wire with a uninsulated coil attached to the tip of the insulated heating coil. The electrical circuit is then made through the heating coil and non-insulated electrode coil into the vascular system and to a body electrode. A catheter may also be used for heating blood within the vascular system which is directly flowed into a tumoral mass for the purposes of thermal treatment of cancer.

US Patent:

59191872, Jul 6, 1999

Filed:

Sep 15, 1995

Appl. No.:

8/528915

Inventors:

Guido Guglielmi - Santa Monica CA
Cheng Ji - Los Angeles CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61B 1738
A61B 1700

US Classification:

606 32

Abstract:

A thrombus is generated in an aneurysm, arteriovenous malformation or fistula by means of a catheter having an insulated heating coil coupled to an insulated delivery wire. In one embodiment, two delivery wires are coupled to heating coils to provide a closed circuit. The heating coils may be in the form of a double helix or a single helix in combination with a straight heating coil. The heating coils are permanently connected to the delivery wires. Alternatively, a single insulated heating coil may be attached to a single insulated delivery wire with a uninsulated coil attached to the tip of the insulated heating coil. The electrical circuit is then made through the heating coil and non-insulated electrode coil into the vascular system and to a body electrode. A catheter may also be used for heating blood within the vascular system which is directly flowed into a tumoral mass for the purposes of thermal treatment of cancer.

US Patent:

59761318, Nov 2, 1999

Filed:

Jun 18, 1996

Appl. No.:

8/666804

Inventors:

Guido Guglielmi - Santa Monica CA
Cheng Ji - Los Angeles CA

Assignee:

The Regents of the University at California - Oakland CA

International Classification:

A61B 1739

US Classification:

606 49

Abstract:

An apparatus is provided for electrocoagulating blood and tissue at an occlusion site by means of application of an alternating signal or current through a detachable partially insulated coil on the end of a microcatheter. A Guglielmi Detachable Coil (GDC) is preferably used in the combination with damped radio frequency energy to cause local heating at the location of the coil but without local ohmicly heated tissue damage or hot spots. Damping of the radio frequency energy facilitates the avoidance of hot spots. Once carbonization of blood at the detachment zone of the GDC coil occurs, the impedance of the entire system increases. The impedance increase is detected to automatically turn off the alternating current and then to apply a direct current to electrolytically detach the GDC coil from the microcatheter.

US Patent:

55692451, Oct 29, 1996

Filed:

Oct 17, 1994

Appl. No.:

8/323662

Inventors:

Guido Guglielmi - Santa Monica CA
Cheng Ji - Los Angeles CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61B 1739

US Classification:

606 49

Abstract:

An apparatus is provided for electrocoagulating blood and tissue at an occlusion site by means of application of an alternating signal or current through a detachable coil on the end of a microcatheter. A Guglielmi Detachable Coil (GDC) is preferably used in the combination with radio frequency energy to cause local heating at the coil. Once carbonization of blood at the detachment zone of the GDC coil occurs, the impedance of the entire system increases. The impedance increase is detected to automatically turn off the alternating current and then to apply a direct current to electrolytically detach the GDC coil from the microcatheter.

US Patent:

60247185, Feb 15, 2000

Filed:

Sep 4, 1997

Appl. No.:

8/923609

Inventors:

Hank H. Chen - St. Louis MO
Cheng Ji - Los Angeles CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61B 1720
A61B 1732

US Classification:

604 22

Abstract:

An ultrasound catheter comprises a coaxial cable of electrical conductors with a piezoelectric element at its distal end. The piezoelectric element is shaped and disposed according to the desired ultrasonic field. When an electrical signal from a signal generator is connected to the electrical conductors, the piezoelectric element mechanically deforms in response and generates ultrasonic energy. An alternative embodiment of the present invention is a hollow tubular catheter of flexible polymer has at its distal end a cylindrical piezoelectric element connected to electrical conductors running the length of the catheter. The piezoelectric cylinder may be tapered, segmented, shortened, etc. according to the desired focusing of the ultrasonic field, which is preferably forwardly focused. In either embodiment the catheter is threaded through a patient's vasculature and brought in close proximity to a vascular occlusion.

US Patent:

58940227, Apr 13, 1999

Filed:

Oct 7, 1997

Appl. No.:

8/946608

Inventors:

Cheng Ji - Los Angeles CA
Guido Guglielmi - Santa Monica CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

A61F 1300
A61K 914

US Classification:

424422

Abstract:

The present invention is an endovascular embolic composition. The embolic composition comprises a hydrophilic insoluble matrix having a microscopic mesh-like structure. The voids or intricacies of the matrix enclose droplets of aqueous solution as well as liquid oil. This structure is essentially equivalent to a "gel" structure with the insoluble matrix including both aqueous and oil droplets within its mesh. In creating the matrix a liquid oil base is mixed with an aqueous solution of a matrix base. The matrix base comprises an organic polymer such as a protein like albumin or its equivalent dissolved in an aqueous solution which may contain additional solutes. The matrix base solution is mixed and emulsified with the liquid oil base at a volume ratio ranging between about 1-to-1 and 1-to-5 respectively. To create the embolic composition the matrix base is then precipitated or cross-linked to form a gel with a mesh-like microscopic structure in which insoluble matrix surrounds and entraps both aqueous fluid and liquid oil. Preferably sclerifying agents are included within the composition so that scar tissue will develop to permanently occlude the embolized vasculature.