Aspirating and removing biological material
The invention generally relates to devices and methods for imaging and aspirating biological material from inside a vessel. In certain embodiments, the invention provides devices that include a body configured to fit within a lumen of a vessel. The body includes an opening. Devices of the invention also include an aspiration channel within the body. The aspiration channel includes a distal end that is connected to the opening. Devices of the invention also include an imaging assembly coupled to the body.
1. A device for imaging and aspirating biological material from inside a vessel of a patient, the device comprising:
a body configured to fit within a lumen of the vessel, the body comprising a sidewall and an opening through the sidewall;
an aspiration channel extending through the body and comprising a distal end that is connected to the opening so that, when suction is applied to a proximal end of the aspiration channel, biological material from inside the vessel is aspirated through the opening in the body;
an imaging assembly coupled to the body and longitudinally fixed with respect to the opening, wherein the imaging assembly is disposed distally of the opening, wherein the imaging assembly images biological material exposed substantially perpendicular to the opening while biological material is simultaneously being aspirated through the aspiration channel from inside the vessel, wherein the imaging assembly comprises an optical fiber having a plurality of stationary optoacoustic sensors each disposed circumferentially relative to the fiber, wherein the fiber comprises a plurality of fiber Bragg gratings each having a grating period that corresponds to one of the plurality of stationary optoacoustic sensors;
a first tunable light source optically coupled to deliver tunable light to the fiber; and
an image processing module configured to receive a plurality of phased array image signals from the fiber, each of the plurality of phased array image signals emanating from one of the plurality of stationary optoacoustic sensors in response to light from the first tunable light source that is tuned to the wavelength of the fiber Bragg grating that corresponds to the optoacoustic sensor, and to synthesize a radial image from the plurality of phased array image signals received from each of the optoacoustic sensors.
2. The device according to claim 1 , further comprising a second light source optically coupled to the fiber to deliver light that is modulated by optical signals received from each of the plurality of optoacoustic sensors to create the phased array image signals.
3. The device according to claim 1 , wherein the imaging assembly images through the opening while biological material is aspirated from inside the vessel.
4. A method for imaging and aspirating biological material from a vessel wall, the method comprising:
providing an imaging and aspirating device comprising:
a body configured to fit within a lumen of a vessel, the body comprising a sidewall and an opening through the sidewall;
an aspiration channel extending through the body and comprising a distal end that is connected to the opening; and
an imaging assembly coupled to the body and longitudinally fixed with respect to the opening, wherein the imaging assembly is disposed distally of the opening, wherein the imaging assembly images the opening, wherein the imaging assembly comprises an optical fiber having a plurality of fiber Bragg gratings each having a grating period that corresponds to one of a plurality of stationary optoacoustic sensors disposed circumferentially relative to the fiber;
inserting the device into a lumen of a vessel;
aspirating biological material from inside the vessel through the opening in the body by applying suction to a proximal end of the aspiration channel; and
simultaneously delivering light pulses from a first tunable light source that is optically coupled to the fiber to thereby image biological material exposed substantially perpendicular to the opening in the body with the imaging assembly while biological material is being aspirated from inside the vessel to thereby provide real-time imagery of biological material as it is being aspirated, wherein the pulses are tuned to the wavelengths of the fiber Bragg gratings corresponding to each of the optoacoustic sensors; and
receiving a plurality of phased array image signals from the fiber, each of the plurality of phased array image signals emanating from the plurality of optoacoustic sensors in response to light from the first tunable light source that is tuned to the wavelength of the fiber Bragg grating that corresponds to the optoacoustic sensor, and synthesizing a radial image from the plurality of phased array image signals received from each of the optoacoustic sensors.
5. The method according to claim 4 , further comprising a second light source optically coupled to the fiber to deliver light that is modulated by optical signals received from each of the plurality of optoacoustic sensors to create the phased array image signals.
6. The method according to claim 4 , wherein the imaging assembly is positioned to image the opening.
7. The method according to claim 4 , wherein biological material comprises a thrombus.
8. The method according to claim 4 , wherein the imaging assembly is disposed distally of the opening.
9. The method according to claim 4 , wherein the imaging assembly is disposed proximate of the opening.
10. The method according to claim 4 , wherein the imaging assembly is longitudinally aligned with the opening.
11. The method according to claim 4 , further comprising:
surrounding the stationary optoacoustic sensors within an optical fiber sensing region having a thickness of about one half of a wavelength of a desired acoustic frequency; and
overlaying a photoacoustic transducer material on the optical fiber sensing region, the photoacoustic transducer material having a thickness of about a quarter of the wavelength of the desired acoustic frequency, the photoacoustic transducer material positioned so that it receives light diffracted by the blazed fiber Bragg grating and emits ultrasonic imaging energy.