The United States of America as Represented by the Administrator of the

United States Surgical Corporation

Other

California Institute of Technology

Baxter International Inc.

Edwards Lifesciences Corporation

Thomas J Pacala

Oleg Shikhman

James Correia

Michael S Kolesa

James B Laudenslager

Barton C Thompson

Robert A Frosch

Iain S McDermid

A controlled advancement laser ablation device is provided for precise ablation of body matter. The laser ablation device includes a laser energy transmission mechanism such as, e.g. a fiber optic fiber mounted for controlled translational longitudinal movement relative to a housing structure. A laser energy generator is optically connected to the laser energy transmission mechanism. A controlled advancement mechanism is provided in engagement with the laser energy transmission mechanism for advancing the mechanism through the housing structure at a controlled rated coordinated with the laser energy generator output to ablate body tissue. Controlled advancement mechanisms include constant and/or variable rate springs, motors, and other mechanisms which can be coordinated with the laser energy generator to advance the laser energy transmission mechanism as the targeted substance is ablated. The device is particularly suitable for use in transmyocardial revascularization (TMR) and angioplasty procedures.

Laser ablation device

A controlled advancement laser ablation device is provided for precise ablation of body matter. The laser ablation device includes a laser energy transmission mechanism such as, e.g., a fiber optic fiber mounted for controlled translational longitudinal movement relative to a housing structure. A laser energy generator is optically connected to the laser energy transmission mechanism. A controlled advancement mechanism is provided in engagement with the laser energy transmission mechanism for advancing the mechanism through the housing structure at a controlled rated coordinated with the laser energy generator output to ablate body tissue. Controlled advancement mechanisms include constant and/or variable rate springs, motors, and other mechanisms which can be coordinated with the laser energy generator to advance the laser energy transmission mechanism as the targeted substance is ablated. The device is particularly suitable for use in transmyocardial revascularization (TMR) and angioplasty procedures.

A controlled advancement laser ablation device is provided for precise ablation of body matter. The laser ablation device includes a handle portion having proximal and distal openings and a fiber advancing device having a stationary member and a movable member. The movable member is movable towards and away from the stationary member. A fiber casing is included having proximal and distal ends. The distal end is secured to the proximal end of the handle portion and the proximal end is secured to the stationary member. At least one optical fiber is included having proximal and distal ends. The distal end is extendible through the handle portion and a portion of the fiber, defined between the proximal and distal ends, is secured to the movable member. A laser energy generator is optically connected to the proximal end of the optical fiber. The handle portion includes a self-biasing advancing mechanism. The self-biasing advancing mechanism includes a guide member positioned within at least a portion of a channel extending within the handle portion. At least one biasing member is operatively connected to the guide member to guide the guide member proximally as a proximal force is applied to the distal end of the optical fiber and to guide the guide member distally when laser energy is transmitted to the optical fiber by the laser energy generator. Controlled advancement mechanisms include constant and/or variable rate springs, motors, and other mechanisms which can be coordinated with the laser energy generator to advance the laser energy transmission mechanism as the targeted substance is ablated. The device is suitable for use in transmyocardial revascularization (TMR) and angioplasty procedures.

Controlled advancement lasing device

A coring device for coring body tissue to define reproducible patent channels in the body tissue is provided. The coring device utilizes a coring member that is rotatable and linearly advanceable at coordinated predetermined rates to core body tissue. The device can include a suction assembly suitable for use during biopsy procedures and a cautery assembly to cauterize the cored body tissue. The coring member can also be oscillated along its longitudinal axis to effect cauterization and/or coring. The coring device is particularly suited for Transmyocardial Revascularization (TMR).

Coring device and method

The present disclosure relates to a method apparatus for transmyocardial revascularization. The apparatus includes an incision needle for creating an incision within a patient's heart to define a channel, and an electrocautery assembly operatively associated with the incision needle for transferring thermal energy to an inner surface of the channel to reduce bleeding therefrom and to prevent the channel from closing. Preferably, thermal energy is not transferred to the epicardium to create a flap or channel cap after the cylindrical incision needle is removed from relevant tissue to reduce bleeding from the channel.

Electrocautery coring using solid needle

Lasing device

A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse-generating circuit is coupled to the laser for generating a high-voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser. A tapered transmission conductor means such as a tapered parallel plate transmission line may be caused to couple one or more saturable inductor switches of one size to a laser of a different size.

Magnetically switched power supply system for lasers

A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending upon the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately.

Multiplex electric discharge gas laser system

A tuning arrangement (10) for a tunable laser comprises a single holographic grating (12) and two flat surface reflective mirrors (13 and 14). The beam (15) from the laser cavity is incident on the grating at a grazing angle for optimum beam expansion. The diffracted beam propogates from the grating to the first mirror (13), therefrom to the second mirror (14) and is reflected at the Littrow angle to the grating, whereat it is diffracted a second time and returned to the second mirror (14) for reflection to the first mirror (13). Therefrom it is reflected back to the grating. After undergoing a third diffraction it is directed back into the cavity for further amplification.

Mirror-grating tuning arrangement for high resolution lasers

A saturable inductor switch for compressing the width and sharpening the rise time of high voltage pulses from a relatively slow rise time, high voltage generator to an electric discharge gas laser (EDGL). The switch also provides a capability for efficient energy transfer from a high impedance primary source to an intermediate low impedance laser discharge network. More specifically, a saturable inductor switch is positioned with respect to a capacitive storage device, such as a coaxial cable, so that when a charge build-up in the storage device reaches a predetermined level, saturation of the switch inductor releases or switches energy stored in the capacitive storage device to the EDGL. Also disclosed are cascaded saturable inductor switches for providing output pulses having rise times of less than ten nanoseconds as required for efficient excitation of EDGL's, the pulse rise time being determined by the thickness of a high permeability material forming the saturable inductor switch. In addition, a technique for magnetically biasing the saturable inductor switch is disclosed so that only pulses from a pulse generator having one polarity are passed and pulses having the other polarity are blocked, thereby improving the lifetime of electrical components that are sensitive to voltage reversals.

Pulse switching for high energy lasers

A helium-nitrogen laser is described in which energy in the visible range is emitted as a result of charge transfer reaction between helium ions and nitrogen molecules. The helium and nitrogen are present in a gas mixture at several atmospheres pressure, with a nitrogen partial pressure on the order of less than one percent. Prior to applying a discharge pulse to the gas mixture at the high pressure by means of a pair of main discharge electrodes, the gas mixture is preionized to prevent arcing when the discharge pulse is applied. The preionization is achieved by the application of a high voltage across a pair of secondary electrodes which are spaced apart in a direction perpendicular to the spacing direction of the main discharge electrodes and the longitudinal axis of the space in which the gas mixture is contained. Feedback, by means of a pair of appropriately spaced mirrors, is provided, to produce coherent energy pulses at a selected wavelength.

Growing community of inventors

Palm Desert, CA, United States of America

Thomas J Pacala