Micro vein enhancer with two lasers and two optical detectors configured for removing surface topology

Patent metadata

Field	Value
Publication number	US-12295744-B2
Application number	US-202318135798-A
Country	US
Kind code	B2
Filing date	Apr 18, 2023
Priority date	Jan 10, 2006
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

A vein imager includes: two photodetectors, a first and second lasers configured to respectively emit an infrared beam of light and a human-visible beam of light; a combiner to coaxially align the two beams; and a scanner that scans the coaxial beam in a pattern and onto a skin surface of a patient. The first photodetector receives the infrared wavelength reflected from the patient as a contrasted image of subcutaneous veins, and surface reflection noise due to skin surface topology, and outputs a first signal representing that contrasted image of subcutaneous veins and noise due to skin surface topology. The second photo detector receives the human-visible wavelength reflected from the skin surface and outputs a second signal representing a contrasted image of the topology. The second signal is subtracted from the first signal to remove the noise, permitting projection of a surface-noise-free vein image onto the skin surface.

First claim

What is claimed is:

1. A vein imager, for use in imaging subcutaneous veins beneath a skin surface of a patient, said vein imager comprising:
a first laser configured to emit a beam of light at an infrared wavelength;
a second laser configured to emit a beam of light at a human-visible wavelength;
a combiner configured to coaxially align said beam of infrared light and said beam of human-visible light to form a single coaxial beam of light;
a scanner configured to scan said coaxial beam of light in a pattern and onto the skin surface of the patient;
a first photodetector being responsive to said infrared wavelength, said first photodetector configured to receive said infrared wavelength of light reflected from the patient as a contrasted image of subcutaneous veins formed by differential absorption and reflection by the subcutaneous veins and the surrounding tissue therein, and as surface reflection noise due to topology of the skin surface; said first photo detector further configured to output a first signal representing said contrasted image of the subcutaneous veins and the skin surface topology;
wherein said second laser is configured to receive said first signal and use said first signal to emit light configured to form said contrasted image toward said scanner, with said scanner configured to thereby project said contrasted image onto the skin surface in a first image frame;
a second photo detector responsive to said human-visible wavelength, said second photo detector configured to receive said human-visible wavelength reflected from the skin surface and to output a second signal representing a contrasted image of the skin surface topology;
a microprocessor, said microprocessor configured to subtract said second signal from said first signal to remove the noise created by the skin surface topology and form a third signal representing a surface-noise-free contrasted image of the subcutaneous veins; and
wherein said second laser is configured to receive said third signal and use said third signal to emit light representing said surface-noise-free contrasted image toward said scanner, with said scanner configured to thereby project said surface-noise-free contrasted image onto the skin surface in one or more image frames after said first image frame.

2. The vein imager according to claim 1 , wherein said combiner comprises: a mirror with a dichroic coating, wherein said dichroic coating is configured to transmit said visible wavelength of light and reflect said infrared wavelength of light.

3. The vein imager according to claim 1 ,
wherein said combiner comprises: a polarizer;
wherein said second laser is positioned to emit said beam of light at the human-visible wavelength at a first polarized orientation to pass through said polarizer; and
wherein said first laser is positioned to emit said beam of infrared light at a second polarized orientation to reflect off said polarizer to form said coaxial beam of light.

4. The vein imager according to claim 1 , wherein said scanner comprises: a mems scanner.

5. The vein imager according to claim 1 , wherein said scanner comprises: a two-dimensional mirror.

6. The vein imager according to claim 5 , wherein said two-dimensional mirror is operated with deflection frequencies of 9.4 kHz and 1.4 kHz.

7. The vein imager according to claim 5 wherein said two-dimensional mirror is operated at a natural resonance frequency to minimize power usage.

8. The vein imager according to claim 1 , further comprising: one or more programmable counters configured to generate a mirror driving signal and to determine a position of said coaxial beam.

9. The vein imager according to claim 1 wherein said pattern is from the group of patterns consisting of: a raster pattern; an oval pattern; a circle pattern; a Lissajous pattern; and a random pattern.

10. The vein imager according to claim 1 wherein said housing is configured for portable handheld use of said vein imager.

11. A vein imager, for use in imaging subcutaneous veins beneath a skin surface of a patient, said vein imager comprising:
a first laser configured to emit a beam of light at an infrared wavelength;
a second laser configured to emit a beam of light at a human-visible wavelength;
a combiner, said combiner configured to combine said beam of infrared light and said beam of human-visible light to form a single coaxial beam of light;
a scanner, said scanner configured to scan said coaxial beam of light in a pattern onto the skin surface;
a first photodetector, said first photodetector configured to receive said infrared wavelength of light reflected from the patient as a contrasted image of subcutaneous veins formed by differential absorption and reflection by the subcutaneous veins and the surrounding tissue therein, and as surface reflection noise due to topology of the skin surface; said first photo detector further configured to output a first signal representing said contrasted image of the subcutaneous veins and the skin surface topology;
wherein said second laser is configured to receive said first signal and use said first signal to emit light configured to form said contrasted image toward said scanner, with said scanner configured to thereby project said contrasted image onto the skin surface;
a second photo detector, said second photo detector configured to receive said human-visible wavelength reflected from the skin surface and to output a second signal representing a contrasted image of the skin surface topology;
a state machine, said state machine configured to subtract said second signal from said first signal to remove the noise created by the skin surface topology and form a third signal representing a surface-noise-free contrasted image of the subcutaneous veins; and
wherein said second laser is configured to receive said third signal and use said third signal to emit light representing said surface-noise-free contrasted image toward said scanner, with said scanner configured to thereby project said surface-noise-free contrasted image onto the skin surface.

12. The vein imager according to claim 11 , further comprising: one or more programmable counters configured to determine a position of said coaxial beam.

13. The vein imager according to claim 11 , wherein said pattern is from the group of patterns consisting of: a raster pattern; an oval pattern; a circle pattern; a Lissajous pattern; and a random pattern.

Assignees

• Accuvein Inc

Inventors

• Goldman Ron
• Hunt David
• Mock Mark
• Marshall Graham
• Conlon Stephen P
• Roth Robert

Classifications

• A61B5/0064

  Body surface scanning · CPC title

• A61B2090/366

  using projection of images directly onto the body · CPC title

• A61B2562/0257

  Proximity sensors · CPC title

• A61B5/150748

  Having means for aiding positioning of the piercing device at a location where the body is to be pierced (means for aiding positioning of devices for bringing media into the body A61M5/427, locating blood vessels A61B5/489) · CPC title

• A61M5/427

  Locating point where body is to be pierced, e.g. vein location means using ultrasonic waves, injection site templates · CPC title