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.
Original patent title: “Noncontact three-dimensional diffuse optical imaging of deep tissue blood flow distribution”
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. Granted to University of Kentucky Research Foundation in 2018 with 13 claims and 5 forward citations, and it is expected to expire in 2036.
Coverage
What does this patent actually cover?
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 (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 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.
The gap
What does this patent NOT cover?
- Does not cover imaging methods that require physical contact between the imaging probe or detector and the tissue (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover imaging deeper than approximately 1.5 cm into the tissue (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover imaging techniques that use light outside the near-infrared spectrum (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover two-dimensional (2D) imaging; it specifically focuses on three-dimensional (3D) image reconstruction (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover methods that do not use optical lenses for both applying and detecting the light (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → 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.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Monitoring blood flow in tissue flaps during reconstructive surgery
Assessing healing and circulation in burn wounds without direct contact
Evaluating blood supply in diabetic foot ulcers
Observing tissue perfusion during organ transplantation procedures
Research tools for studying microcirculation in biological tissues
Why it matters
The bigger picture
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.
Filed
March 23, 2016
Granted
January 9, 2018
Market context
Who's building on this
Companies in this space
Companies specializing in medical imaging, surgical tools, and non-invasive diagnostics are likely developing or using similar technologies. This includes major medical device manufacturers like Canon Medical Systems and Siemens Healthineers, as well as various startups focused on optical coherence tomography (OCT) or diffuse optical tomography (DOT) for clinical applications. The University of Kentucky Research Foundation, as the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, may also continue to licenselicensePermission from the patent owner to make, use, or sell the invention — usually in exchange for payment. Doesn't transfer ownership.Read more → or develop this technology for new applications.
Market impact
This patent contributes to the growing field of non-invasive medical diagnostics, particularly for monitoring tissue viability and perfusion. By enabling non-contact 3D imaging of blood flow, it offers a safer and less disruptive alternative to traditional contact-based methods. This could lead to improved patient outcomes in surgeries involving tissue grafts, wound care, and other areas where precise, gentle blood flow assessment is crucial, potentially expanding the market for advanced optical imaging devices in clinical settings.
Claim 1 — Plain English
What this patent covers
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.
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.
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).
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Moderate
Citation count
16/40
Early citations
Claim breadth
9/20
Moderate scope
Recency
10/20
Granted 5–10 years ago
Assignee scale
20/20
Major company or institution
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$66K – $211K
Midpoint $132K · 9.5 yr remaining · industry ×2.2
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Patent Claims
0 independent claims · 1 dependent
Claims are the legal boundaries of the patent. An independent claim stands alone. A dependent claim adds limitations to its parent, narrowing — but not broadening — the scope.
The original legal language
Original claims
13 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Lin, Y., Huang, C., & Yu, G. (2018). Seeing Blood Flow Deep Inside Tissue Without Touching It (U.S. Patent No. 9,861,319). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/9861319/noncontact-three-dimensional-diffuse-optical-imaging-of-deep-tissue-blood-flow-d
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
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).
Patent monitoring