INVESTIGATION OF BODY STRUCTURES

• US 20090292202A1
• Filed: 12/15/2005
• Published: 11/26/2009
• Est. Priority Date: 12/20/2004
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Van Herpen, Maarten, Presura, Cristian
• Granted Patent: US 8,185,189 B2
• Time in Patent Office: Days
• US Class Current: 600/437
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/489 Blood vessels

Abstract

A pulsed radiation beam is directed toward a body structure having a configuration or physical characteristic that changes over time, the radiation being pulsed at a pulse modulation frequency. A detector detects acoustic oscillations set up in the body resultant from the incident pulsed radiation and produces an output signal representative of one or more parameters of the acoustic oscillations. A control system controls operation of the radiation delivery and a processor to process the detector output signal. The pulse modulation frequency of the pulsed radiation is changed over a predetermined range of modulation frequencies and the processor determines the structure resonant frequency from the detector output.

Claims

1. Apparatus for investigation of a body structure (4) having a configuration or physical characteristic that changes over time, the apparatus comprising:

a radiation delivery arrangement (1, 7, 8) arranged to direct pulsed radiation (2) toward the body structure, wherein the radiation is pulsed at a pulse modulation frequency;

a detector arrangement (6, 9) for detecting acoustic oscillations set up in the body resultant from the incident pulsed radiation (2) and arranged to produce an output signal representative of one or more parameters of the acoustic oscillations;

a control system arranged to control operation of the radiation delivery arrangement, the control system including a processor arranged to process the detector output signals;

wherein the pulse modulation frequency of the pulsed radiation is changed over a predetermined range of modulation frequencies and the processor determines the structure resonant frequency from the detector output.

2. Apparatus according to claim 1, wherein the radiation delivery arrangement (1, 7, 8) is controlled to emit radiation (2) pulsed at a pulse modulation frequency matched to the structure resonant frequency determined by the processor.

3. Apparatus according to claim 1, wherein the structure resonant frequency varies over time and the control system alters the pulse modulation frequency to match the structure resonant frequency over time.

4. Apparatus according to claim 1, wherein the pulsed radiation is of a preselected spectral wavelength profile matching an absorption characteristic of the structure or a medium related to the structure.

5. Apparatus according to claim 1, wherein the pulsed radiation is laser radiation.

6. Apparatus according to claim 1, wherein the pulsed radiation is in the form of a pulsed directed beam.

7. Apparatus according to claim 1, wherein the detector arrangement includes a piezoelectric transducer.

8. Apparatus according to claim 1, wherein the detector arrangement comprises an optical detector arrangement.

9. Apparatus according to claim 1, wherein the radiation delivery arrangement and detector arrangement enable data to be captured from a line, section area or volume and the processor includes image rendering means for processing the detector arrangement data and enabling rendering of an image on a display.

10. A method of investigating a body structure (4) having a configuration or physical characteristic that changes over time, the method comprising:

directing pulsed radiation (2) toward the body structure, wherein the radiation is pulsed at a pulse modulation frequency;

detecting (6) acoustic oscillations set up in the body resultant from the incident pulsed radiation and producing an output signal representative of one or more parameters of the acoustic oscillations;

adjusting the pulse modulation frequency of the pulsed radiation is over a predetermined range of modulation frequencies and

from the detected acoustic oscillations determining the structure resonant frequency.

11. A system enabling investigation of a body structure having a configuration or physical characteristic that changes over time, the system comprising means for determining the resonant frequency of the structure by analysing data representative of:

output signals from a detector arrangement for detecting acoustic oscillations set up in the body or structure resultant from pulsed radiation directed toward the structure, and

the variation of a pulse modulation frequency of the pulsed radiation over a predetermined range of modulation frequencies.

12. A system according to claim 17, enabling physical properties of the structure to be determined as a result of analysing the time difference resonant frequencies predicted for the structure.