Abstract
This technical note presents a standardized method that integrates intravascular laser irradiation of blood (ILIB) with infrared thermography to visualize real-time physiological responses during treatment. One adult male with long-standing type 2 diabetes underwent ten ILIB sessions using a 660 nm transcutaneous laser applied over the left radial artery. Infrared thermography captured temperature changes in abdominal regions associated with metabolic function. Across sessions, an average temperature increase of approximately 2.1 °C was observed in the hepatic and epigastric areas. Laboratory values showed reductions in fasting glucose (−29%) and HbA1c (−14%), while C-peptide remained stable. Because this is a single-patient technical demonstration, the findings cannot be interpreted as evidence of efficacy. Instead, the report illustrates the feasibility and potential utility of combining ILIB with thermal imaging for methodological development in future controlled studies.
1 Introduction
Photobiomodulation delivered through intravascular laser irradiation of blood (ILIB) has been explored for its potential effects on microcirculation and cellular bioenergetics (, ). Infrared thermography offers a non-invasive means of monitoring superficial temperature distributions, which may indirectly reflect physiological changes related to blood flow and metabolic activity (). When combined, ILIB and thermal imaging provide an opportunity to document immediate physiological responses that occur during laser application.
The aim of this technical note is to present a reproducible protocol integrating ILIB with infrared thermography and to illustrate its feasibility in a representative patient. This work focuses solely on methodological demonstration rather than clinical evaluation.
2 Materials and methods
2.1 Study design
This report describes a technical demonstration using one adult patient. The goal was to document the combined use of ILIB and thermography rather than assess therapeutic outcomes.
2.2 Patient information
A 62-year-old male with a 30-year history of type 2 diabetes participated. Baseline laboratory results included fasting glucose 331 mg/dL, HbA1c 8.5%, and C-peptide 0.83 ng/mL. His antidiabetic therapy (NPH insulin plus oral medications) remained unchanged throughout the demonstration period.
2.3 ILIB intervention protocol
ILIB was performed using a 660 nm ± 10 nm InGaAlP red laser (100 mW ± 20%). The procedural setup, including probe placement and imaging configuration, is illustrated in Figure 1. The probe was positioned transcutaneously over the left radial artery. Each session lasted 30 min, delivered twice weekly for ten sessions. The patient rested for 15 min before imaging. Protective eyewear was used throughout all procedures.
Figure 1
2.4 Imaging procedure
Infrared thermographic imaging was performed using a FLIR C5 camera (160 × 120 pixels; 8–14 µm spectral range) placed 1.3 m above the thoracoabdominal region. Images were collected at baseline and at 10, 20, and 30 min during each ILIB session. Regions of interest (ROI) included the right hypochondrium, the epigastrium, and the periumbilical area.
2.5 Environmental conditions and monitoring
Room temperature was controlled at 23 °C with 50% relative humidity. Airflow remained below 0.2 m/s. The patient was positioned supine on a gurney. Vital signs—blood pressure, heart rate, respiratory rate, and oxygen saturation—were recorded every 10 min using a multiparameter monitor.
2.6 Data recording
Temperature values from the ROIs were extracted using the camera's analysis tools. Because this is a technical demonstration, thermal patterns were interpreted descriptively without quantitative validation or inter-observer comparison.
3 Results
Thermal imaging consistently demonstrated progressive increases in abdominal temperature during each ILIB session (Figure 2). The hepatic and epigastric ROIs displayed a mean temperature rise of approximately 2.1 °C between baseline and 30 min. These patterns were reproducible across the ten sessions and are summarized visually in the composite thermal map shown in Figure 3.
Figure 2
Figure 3
Vital signs remained within normal ranges throughout. Minor fluctuations in blood pressure were observed but are likely attributable to situational responses, including possible white-coat effect.
Following the ten-session protocol, fasting glucose decreased from 331 to 234 mg/dL (−29%), and HbA1c decreased from 8.5% to 7.3% (−14%). C-peptide levels changed minimally (−3%). These laboratory values are presented in Table 1 for clarity. Three nocturnal hypoglycemic episodes occurred and were resolved with carbohydrate intake. These metabolic results are presented solely as observational findings and cannot be attributed to ILIB.
Table 1
| Date | Fasting glucose | Change (%) | HBA1C | Change (%) | C-peptide | Change (%) |
|---|---|---|---|---|---|---|
| 17/10/2023 | 331 mg/dL | – | 8.5% | – | 0.83 | – |
| 04/12/2023 | 234 mg/dL | −29% | 7.3% | −14% | 0.80 | −3.6% |
Laboratory values before and after ten ILIB sessions, including percentage changes. The table summarizes fasting glucose, HbA1c, and C-peptide values used for descriptive comparison.
4 Discussion
This technical demonstration illustrates that infrared thermography can be paired with ILIB to visualize physiological changes during treatment. The temperature increases observed over the abdominal regions align with previous descriptions of photobiomodulation-associated changes in microcirculation (, ). Comparative studies of photobiomodulation and ILIB protocols have also reported physiological changes detectable through imaging or biochemical markers, supporting the rationale for combining ILIB with real-time monitoring tools (). However, thermography is an indirect assessment tool susceptible to multiple confounding influences, including environmental factors, emotional state, and autonomic responses.
Metabolic changes observed in this patient must be interpreted carefully. Single-subject observations cannot distinguish true intervention effects from natural glycemic variability, medication adherence, dietary fluctuations, or regression to the mean. Previous ILIB literature emphasizes the need for well-controlled trials before drawing clinical conclusions (, ). Percentage changes are reported for descriptive clarity but do not imply statistical significance.
Mechanistic explanations—such as ATP modulation, nitric oxide release, reactive oxygen species regulation, or improved endothelial function—were not evaluated in this demonstration and remain hypothetical. Future investigations should include biochemical assays, vascular imaging, and continuous glucose monitoring to evaluate physiological pathways more thoroughly. This technical demonstration illustrates that infrared thermography can be paired with ILIB to visualize physiological changes during treatment. The temperature increases observed over the abdominal regions align with prior descriptions of photobiomodulation-associated changes in microcirculation (, ). However, thermography is an indirect assessment tool susceptible to multiple confounding influences, including environmental factors, emotional state, and autonomic responses.
Metabolic changes observed in this patient must be interpreted carefully. Single-subject observations cannot distinguish true intervention effects from natural glycemic variability, medication adherence, dietary fluctuations, or regression to the mean. Previous ILIB literature emphasizes the need for well-controlled trials before drawing clinical conclusions (, ). Percentage changes are reported for descriptive clarity but do not imply statistical significance.
Mechanistic explanations—such as ATP modulation, nitric oxide release, reactive oxygen species regulation, or improved endothelial function—were not evaluated in this demonstration and remain hypothetical. Future investigations should include biochemical assays, vascular imaging, and continuous glucose monitoring to evaluate physiological pathways more thoroughly.
5 Limitations
This technical note carries inherent limitations. As a single-case demonstration, the findings cannot be generalized or interpreted as indicators of clinical benefit. The absence of a control condition restricts the ability to distinguish ILIB-related responses from natural physiological variability. Dietary intake, physical activity, body weight, and medication adherence were not monitored, although these factors are known to influence glycemic and metabolic parameters.
Thermographic assessment was qualitative and lacked inter-observer reliability testing or standardized quantitative ROI analysis. Thermal measurements are sensitive to environmental and physiological noise, which may influence interpretation. Additionally, no complementary physiological measurements—such as Doppler ultrasound, biochemical assays, or continuous glucose monitoring—were performed. Consequently, mechanistic explanations remain speculative.
Blood pressure variations may reflect situational or white-coat effects rather than treatment-induced changes. Finally, the ILIB parameters described here should not be considered optimized for clinical use. Larger controlled studies with standardized imaging protocols and comprehensive physiological monitoring are required to evaluate reproducibility, safety, and clinical relevance.
6 Conclusions
This technical note demonstrates an innovative and feasible protocol that integrates intravascular laser irradiation of blood (ILIB) with infrared thermography to monitor physiological responses in real time. The combination of these two techniques provides a standardized and reproducible workflow capable of capturing dynamic thermal patterns associated with metabolic activity. Importantly, this approach introduces a novel imaging-based framework for evaluating systemic photobiomodulation procedures, offering a level of visualization that has not been previously reported in ILIB applications.
Although this single-patient demonstration cannot support clinical inference, the protocol establishes a methodological foundation that can be directly incorporated into future controlled studies. By enabling objective thermal monitoring during ILIB, the proposed model has the potential to improve procedural standardization, support mechanistic investigation, and guide the development of optimized ILIB parameters for metabolic and microcirculatory research. This work expands the technical toolbox available to the photobiomodulation field and may contribute to more rigorous experimental designs in upcoming clinical investigations.
Statements
Data availability statement
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.
Ethics statement
The studies involving humans were approved by Faculty of Medicine, Sao Paulo University. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.
Author contributions
PC: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. GB: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. MB: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing. KA: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing.
Funding
The author(s) declared that financial support was not received for this work and/or its publication.
Conflict of interest
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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The author(s) declared that generative AI was not used in the creation of this manuscript.
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Summary
Keywords
diabetes mellitus, laser therapy, low-level light therapy, thermography, type 2
Citation
Candido PAC, Brioschi GC, Brioschi ML and Altruda KM (2026) Infrared imaging and intravascular laser irradiation of blood therapy for glycemic control in type 2 diabetes mellitus: a technical note. Front. Med. Technol. 7:1701628. doi: 10.3389/fmedt.2025.1701628
Received
08 September 2025
Revised
28 November 2025
Accepted
19 December 2025
Published
03 February 2026
Volume
7 - 2025
Edited by
Stefano Laureti, University of Calabria, Italy
Reviewed by
Erick Argüello-Prada, Universidad Militar Nueva Granada, Colombia
Domenico Carni, University of Calabria, Italy
Updates
Copyright
© 2026 Candido, Brioschi, Brioschi and Altruda.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Philype Antonio Calazans Candido philypecalazans@hotmail.com
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.