Surgery – Truss – Pad
Patent
1996-02-20
1998-02-17
Lateef, Marvin M.
Surgery
Truss
Pad
12866203, A61B 800
Patent
active
057182310
DESCRIPTION:
BRIEF SUMMARY
This application claims benifit of intenational application PCT/GB94/01276, filed Jun. 14, 1994.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to probes having a forward-looking ultrasound receiver and an optical fibre for directing laser signals to a target to generate ultrasound to be sensed by the ultrasound receiver, especially for use in intra-arterial imaging and, preferably, therapy.
2. Description of Related Art
It has been proposed, in a paper entitled "Analysis of the acoustic response of vascular tissue irradiated by an ultraviolet laser pulse" by H. Crazzolara et al. (J. Appl. Phys. 70 (3), 1847-9, 1991), to use an ultrasound probe having a disc of a piezoelectric polymer, specifically polyvinylidene fluoride (PVDF), supported on an end of a metal rod element, to monitor the ultrasound generated during oblation of a target by incidence upon it of laser beam pulses emitted from an end of an optical fibre which is physically separate from the ultrasound probe, thereby to distinguish between incidence of the laser pulses on normal arterial wall material and on calcified hard tissue of a sample of arterial material being investigated in vitro.
Probes of the general kind to which the present invention relates have also previously been described, in UK Patent Specification No. 2212920, which describes inter alia such a probe in which the ultrasound receiver has a dished circular transducer element of a piezoelectric polymer material such as PVDF, and an optical fibre projects coaxially through the centre of the transducer element and has an end, in front of the transducer element, from which laser beam pulses are emitted in use of the apparatus to strike a target, preferably at a focus of the dished transducer element, causing it to emit laser-induced ultrasound signals which are received by the transducer element, thus enabling the target to be investigated ultrasonically.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved laser ultrasound probe, suitable for intravascular use, of the kind having an ultrasonic transducer element having an ultrasound receiving surface of piezoelectric polymeric material and an optical fibre with one end directed forwardly from that surface and arranged to receive laser radiation for transmission through the optical fibre and emission from the the one end thereof.
According to one aspect of the invention, the optical fibre of such a probe is coupled with a laser source adapted to provide alternatively a relatively low average power laser beam which, when modulated or pulsed and emitted from the one end of the optical fibre and incident on a target, will generate ultrasound at an intensity suitable to be received by the transducer element and converted thereby into electrical monitoring signals, and a relatively high average power laser beam suitable, when incident on the said target, to produce ablation thereof, the transducer element being sufficiently robust to withstand the ultrasound which is then also generated.
According to another aspect of the invention, the optical fibre of such a probe is coupled with a laser source adapted to provide alternatively a relatively low average power laser beam at a first wavelength which, when modulated or pulsed and emitted from the one end of the optical fibre into a medium which is highly absorptive at that wavelength, will cause the medium to generate and propagate ultrasound at an intensity suitable to be reflected by a target contacted by said medium and received by the transducing element and converted thereby into electrical monitoring signals, and a relatively high average power laser beam at a second wavelength at which the medium is transmissive and suitable, when incident on the target, produce ablation thereof, the transducing element being sufficiently robust to withstand the ultrasound which is then also generated.
In a particular form of this last-mentioned probe one end of the optical fibre is directed in a forward longitudinal direction
REFERENCES:
patent: 4887605 (1989-12-01), Angelsen et al.
patent: 5163432 (1992-11-01), Ueno et al.
patent: 5254112 (1993-10-01), Sinofsky et al.
Salimbeni, "Shock Wave Models Keep Laser Surgeons on Target", OLE, Jun. 1994, pp. 37-39.
Crazzolara, "Analysis of the Acoustic Response of Vascular Tissue Irradiated by an Ultraviolet Laser Pulse", J. Appl. Phys. 70(3), 1 Aug. 1991, pp. 1847-1849.
White, "Intravascular Ultrasound Guided Holmium: YAG Laser Recanalization of Occluded Arteries", Lasers in Surgery and Medicine 12:239-245 (1992).
Dewhurst, "Developments in a Photoacoustic Probe for Potential Use in Intra-Arterial Imaging and Therapy", Acoustical Imaging, vol. 21.
Patent Abstracts of Japan, vol. 15, No. 252 (C-0844) Jun. 26, 1991, & JP,A,30 082 482 see abstract.
Patent Abstracts of Japan, vol. 15, No. 337 (C-0862) Aug. 27, 1991, & JP,A, 31 031 242 see abstract.
Chen Qing Xin
Dewhurst Richard James
Pang Kok Fu
Payne Peter Alfred
British Technology Group Ltd.
Fields Derrick
Lateef Marvin M.
LandOfFree
Laser ultrasound probe and ablator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Laser ultrasound probe and ablator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser ultrasound probe and ablator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1777014