# Seeing Blood Flow Deep Inside Tissue Without Touching It

> This patent describes a way to create 3D images of blood flow up to 1.5 cm deep inside body tissue using near-infrared light, all without any physical contact with the skin.

- **Patent:** US 9861319
- **Original title:** Noncontact three-dimensional diffuse optical imaging of deep tissue blood flow distribution
- **Owner:** University of Kentucky Research Foundation
- **Granted:** 2018
- **Status:** Active
- **Times cited:** 5
- **Field:** medical_devices, biotech, software, consumer_electronics

## What it does

This patent details an optical method for creating three-dimensional (3D) images of blood flow in deep tissue, specifically up to about 1.5 cm, without needing to touch the tissue (Claim 1). It works by projecting near-infrared light from long-coherence laser sources onto the tissue surface through optical lenses. A detector array then captures the diffused near-infrared light reflected back, also through lenses (Claim 1). The collected data is then processed, often using a finite-element-method (FEM), to reconstruct a 3D image of the blood flow distribution (Claim 6). For example, a surgeon could use this system to check the blood supply in a delicate skin graft during surgery without disturbing the healing tissue.

## What it does NOT cover

- Does not cover imaging methods that require physical contact between the imaging probe or detector and the tissue (Claim 1).
- Does not cover imaging deeper than approximately 1.5 cm into the tissue (Claim 1).
- Does not cover imaging techniques that use light outside the near-infrared spectrum (Claim 1).
- Does not cover two-dimensional (2D) imaging; it specifically focuses on three-dimensional (3D) image reconstruction (Claim 1).
- Does not cover methods that do not use optical lenses for both applying and detecting the light (Claim 1).

## The clever bit

The novelty lies in combining non-contact near-infrared light application and detection with advanced 3D image reconstruction techniques, such as the finite-element-method, to accurately map deep tissue blood flow in tissues with arbitrary shapes. This allows for safe, detailed analysis of vulnerable or sensitive tissues.

## Real-world examples

1. Monitoring blood flow in tissue flaps during reconstructive surgery
2. Assessing healing and circulation in burn wounds without direct contact
3. Evaluating blood supply in diabetic foot ulcers
4. Observing tissue perfusion during organ transplantation procedures
5. Research tools for studying microcirculation in biological tissues

## Why it matters

This technology is important because it allows medical professionals to assess blood flow in sensitive, vulnerable, or damaged tissues without physical contact. This non-contact approach reduces the risk of infection, further injury, or disruption to healing processes. It is particularly valuable for monitoring open wounds, surgical sites, or delicate tissue grafts where traditional contact-based methods would be problematic.

## Frequently asked questions

### What does Seeing Blood Flow Deep Inside Tissue Without Touching It cover?

This patent describes a way to create 3D images of blood flow up to 1.5 cm deep inside body tissue using near-infrared light, all without any physical contact with the skin.

### Who owns patent US 9861319?

University of Kentucky Research Foundation owns this patent, granted in 2018.

### When does this patent expire?

This patent is expected to expire on March 23, 2036, when the invention enters the public domain.

### What is patent US 9861319 cited by?

This patent has been cited by 5 later patents that build on its ideas.

### What problem does this patent solve?

This technology is important because it allows medical professionals to assess blood flow in sensitive, vulnerable, or damaged tissues without physical contact. This non-contact approach reduces the risk of infection, further injury, or disruption to healing processes. It is particularly valuable for monitoring open wounds, surgical sites, or delicate tissue grafts where traditional contact-based methods would be problematic.

### What does this patent NOT cover?

Does not cover imaging methods that require physical contact between the imaging probe or detector and the tissue (Claim 1).

**Full plain-English explainer:** https://patentbrief.org/patent/us/9861319/noncontact-three-dimensional-diffuse-optical-imaging-of-deep-tissue-blood-flow-d

**Original patent:** https://patents.google.com/patent/US9861319

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

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- [How to Take 3D Pictures Inside Human Tissue Using Near-Infrared Light](https://patentbrief.org/patent/us/RE38800/digital-video-recorder-dvr) — A system that uses flexible fiber optic cables to map the inside of complex body parts by shining light through them and measuring how it scatters.
- [How to Create Wide-Field Images of Tissue Using OCT Scanners](https://patentbrief.org/patent/us/9677869/autonomous-spaceport-drone-ship-asds) — A method for stitching together multiple high-resolution medical images of uneven tissue samples to create a single, wide-field view for better diagnostic clarity.
- [Using Different Light Colors to Detect Touches on Screens](https://patentbrief.org/patent/us/20110234542/methods-and-systems-utilizing-multiple-wavelengths-for-position-detection) — This 2011 patent describes a system that uses two different colors of light to accurately detect where an object, like a finger, touches a screen or surface.
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- [Fixing Blurry Tomography Scans from Patient Movement](https://patentbrief.org/patent/us/10307129/apparatus-and-method-for-reconstructing-tomography-images-using-motion-informati) — This patent describes a method for creating clearer 3D medical scans by using two different X-ray scans to detect and correct for patient movement during the imaging process.
