System for measuring a biological parameter by means of photoacoustic interaction
First Claim
1. A sensor head for use in photoacoustic in vivo measurement, comprising a housing shaped to engage a selected body part, transmission means terminating in said housing so as to transmit light energy from a light source to enter the body part along a beam axis, and acoustic transducer means mounted in the housing to receive acoustic waves generated by photoacoustic interaction within the body part, the acoustic transducer means being disposed in the housing to receive said acoustic wave in a direction of high acoustic energy.
0 Assignments
0 Petitions
Accused Products
Abstract
A system for measuring a biological parameter, such as blood glucose, the system comprising the steps of directing laser pulses from a light guide into a body part consisting of soft tissue, such as the tip of a finger to produce a photoacoustic interaction. The resulting acoustic signal is detected by a transducer and analyzed to provide the desired parameter.
14 Citations
61 Claims
- 1. A sensor head for use in photoacoustic in vivo measurement, comprising a housing shaped to engage a selected body part, transmission means terminating in said housing so as to transmit light energy from a light source to enter the body part along a beam axis, and acoustic transducer means mounted in the housing to receive acoustic waves generated by photoacoustic interaction within the body part, the acoustic transducer means being disposed in the housing to receive said acoustic wave in a direction of high acoustic energy.
-
14. A sensor head for use in photoacoustic in-vivo measurements, comprising a housing shaped to receive a removable insert;
- a removable insert that engages a selected body part, the insert being fitted to an individual, allowing for a range of sizes of body parts to be used;
light transmission means terminating in or near said removable insert so as to transmit light energy from a light source to enter the body part along a beam axis; and
an acoustic transducer means mounted in the housing or in the removable insert to receive acoustic waves generated by photoacoustic interaction within the body part, the acoustic transducer means being disposed in the housing or insert to receive said acoustic waves in a direction of high acoustic energy.
- a removable insert that engages a selected body part, the insert being fitted to an individual, allowing for a range of sizes of body parts to be used;
-
49. A method of measuring a biological parameter in a subject, the method comprising the steps of:
-
directing one or more pulses of optical energy from the exterior into the tissue of a subject along a beam axis, the optical energy having a wavelength selected to be absorbed by tissue components of interest, thereby to produce a photoacoustic interaction;
detecting acoustic energy resulting from said photoacoustic reaction by means of a transducer positioned to intercept acoustic energy propagating in a direction other than the forward direction of said beam axis; and
deriving from said detected acoustic energy a measure of the parameter of interest. - View Dependent Claims (52, 53)
-
-
54. Apparatus for measuring a biological parameter in a subject, the apparatus comprising:
-
means for directing one or more pulses of optical energy from the exterior into the tissue of a subject along a beam axis, the optical energy having a wavelength selected to be absorbed by tissue components of interest, thereby to produce a photoacoustic interaction;
transducer means arranged to detect acoustic energy resulting from said photoacoustic reaction by intercepting acoustic energy propagating in a direction other than the forward direction of said beam axis; and
means for deriving from said detected acoustic energy a measure of the parameter of interest. - View Dependent Claims (55, 57, 58, 60)
-
-
56. A method of correcting measurement of an analyte based on a photoacoustic signal obtained from a living being comprising determining the concentration of other constituents in the being which have a significant effect on the photoacoustic signal and tend to vary from individual to individual or over time, and adjusting the measurement to remove the effect of variations in the concentrations of said other constituents.
-
59. A method of establishing a photoacoustic signal obtained from a living being comprising using the ratio of the acoustic signal obtained to the optical signal which generated the acoustic signal to determine the concentration of an analyte present in said being.
-
61. A method of normalizing a photoacoustic signal obtained from directing an optical beam on the tissue of a living being comprising determining the dependence of the photoacoustic signal on the energy of the optical beam from a series of measurements at different energies for the type of tissue involved.
Specification