摘要:
A method of selecting laser parameters for performing laser-assisted transmyocardial revascularization (TMR) to avoid inducing undesired cardiac arrhythmia without synchronization of delivery of laser energy and the patient's cardiac cycle, the method comprising the steps of minimizing the power level of laser energy used, thereby decreasing the overall trauma to the heart, selecting a pulse frequency as great as possible while avoiding adverse summation effects, selecting a pulse width as wide as possible to prevent excessively high peak powers per pulse and not so wide as to cause undesired thermal damage, selecting an energy flux rate, shaping the front end of each pulse of laser energy to provide efficient, non explosive TMR channeling, and correcting the selected power level, pulse width, pulse frequency and energy flux rate for mechanical events, including method of access to the heart, position of selected portions of myocardium in the heart, temporal duration of the procedure, natural movement of the heart, specific heart geometry, pre-existing heart arrhythmia and other factors causing a predisposition to heart arrhythmia. A method for performing laser-assisted transmyocardial revascularization (TMR) using such laser energy with parameters selected to avoid inducing undesired cardiac arrhythmia, the method comprising the steps of generating laser energy having a predetermined non-square wave shape, a predetermined wavelength, a predetermined energy flux and a predetermined power level, and delivering the laser energy in a plurality of pulses, the plurality of pulses having a predetermined pulse frequency and a predetermined pulse width, to selected portions of myocardium to form TMR channels in myocardium without synchronizing delivery of the laser beam with the cardiac cycle.
摘要:
A steerable percutaneous catheter for guiding at least one functional device to selected surfaces of a body for treatment thereon, particularly adapted for laser-assisted Percutaneous Transmyocardial Revascularization (PTMR). The steerable catheter has a handle portion at its proximal end and a controllably deflectable end portion at its distal end. The distal end of the catheter and the distal end of the functional device maintain alignment automatically during deflection. The invention also includes a surface contact detection system to detect contact with an interior body surface, such as the heart wall.
摘要:
A steerable drug delivery catheter and method of use, particularly adapted for percutaneous use. The distal end of the drug delivery catheter is deflectable. The catheter has a relative movement compensation mechanism for maintaining positioning between the distal end of the drug delivery catheter and the distal end of the drug delivery device therein.
摘要:
Improved methods and apparatuses related to laser-assisted intra-coronary transmyocardial revascularization (ITMR), and more particularly, to improved methods and apparatuses for directing an interventional catheter device, via percutaneous or other entry into the vasculature, for example at the femoral artery, over the aortic arch, through the ascending aorta and over the coronary ostia such that the laser delivery means can be positioned inside a coronary artery and laser energy is used to create a plurality of small channels through the coronary artery into the tissue of the myocardium. An proximal hub portion and method of using it are described, the proximal hub portion adapted for attachment to a central, elongated lumen portion, the proximal hub portion optionally having a plurality of branched extending arms, the sheath and associated branched arms having individual blood loss seals and individually capable of receiving a laser delivery means, visualization or marking means, or other tools. The interventional catheter device has a distal end with, optionally, a guide means for directing an advancing laser delivery or other device to an angle with respect to the central axis of the catheter device, the distal end optionally comprising a radio-opaque portion for visualization via a fluoroscope or other means, the distal end of the catheter device further comprising an ultrasound transducer for visualizing the orientation and firing angles of the catheter device. The methods of use also comprise placing channel opening blockers, such as an angioplasty-type inflatable balloon or an axially compressible, radially expandable stainless steel wire mesh or other material stent in place inside the coronary artery, thereby preventing undesired bleeding from the coronary artery.
摘要:
Apparatus for treating a patient's heart by stimulating revascularization of the heart or creating channels in the heart. The apparatus includes a catheter, a laser energy source coupled to the catheter, and a control circuit. The control circuit is configured to cause the laser energy source to deliver an output of laser energy over a first time period shorter than a heart beat cycle.
摘要:
A bow shaped, integrated wire catheter apparatus and method of use for access to, and laser or other treatment within, cavities and organs in the human body, the apparatus having a curvilinear shape but flexible enough to assume a generally elongated shape such that the apparatus can be extended through the vasculature in the generally elongated shape and can assume the curvilinear shape when extended into a body cavity or organ, the curvilinear shape serving to securely position the apparatus adjacent a selected surface within the body cavity or organ for laser or other treatment with a laser delivery device or other functional device thereon, the apparatus having a central axis, the apparatus comprising a main catheter shaft having a proximal end and an apex seeking and stabilizing distal end, the main catheter shaft having material of construction or other mechanism or means for causing a portion of the catheter shaft to have a bowed shape adjacent its distal end, the main catheter shaft having at least one hollow lumen extending axially and at least partially therethrough such that a bow shaped portion defines and distinguishes an outer arcuate sidewall for placement in contact with the selected area or areas for laser or other treatment thereon, and an inner arcuate sidewall, at least the outer arcuate sidewall having one or more guide holes disposed thereon for selectively providing laser or other treatment on the selected surface by controllably advancing a laser delivery device or other functional device selectively through the one or more guide holes to the selected surface. The catheter apparatus can be made at least partially of superelastic and/or shape memory materials of construction.
摘要:
A catheter device and a method for using same to facilitate removal of obstructive material in a human body channel. The catheter comprises an elongated body with a distal end portion adapted to be inserted within the channel and a proximal end portion. A lumen, extending lengthwise through said catheter body, supports a guidewire having a distal end along which the catheter body can be moved within the channel. A series of parallel, closely spaced fiber members extend through the catheter body from its proximal end and terminate near a distal end face of said catheter. Laser energy supplied at the catheter's proximal end is transmitted along the fiber members and is emitted forwardly therefrom at the catheter's distal end face. In one embodiment the catheter has a tapered nose portion for displacing obstructive material in the body channel before the emission of laser energy. In another embodiment, the fiber members are movable longitudinally in unison to sever and trap obstructive material which is removed from the body channel.