Alzheimer's disease (AD), the most common cause of dementia, is a progressive neurodegenerative disorder characterized by cognitive decline, including impaired learning ability, memory loss, and behavioral disturbances.

According to surveys conducted by the Ministry of Health and Welfare in Taiwan, the prevalence of dementia among individuals aged 65 years and older was estimated at 7.86% in 2018, affecting more than 280,000 individuals, and is projected to approach 900,000 by 2065, resulting in substantial medical, social, and economic burdens. Current pharmacological treatments provide only limited symptomatic benefits and may be associated with adverse effects. Therefore, safe and effective non-pharmacological interventions that may support cognitive function and reduce caregiver burden are urgently needed.

Experimental studies suggest that far-infrared (FIR) irradiation may enhance mitochondrial oxidative phosphorylation, increase ATP production, and promote microglial amyloid-β clearance, which may help delay the progression of Alzheimer's disease.

This trial aims to investigate the safety and effects of far-infrared (FIR) therapy on cognitive function in patients with Alzheimer's disease.

The findings may support the clinical application of FIR therapy as a non-pharmacological intervention to improve cognitive function and quality of life, reduce medication burden and treatment-related side effects, lessen caregiver burden, delay institutionalization, and reduce the social and economic burden associated with Alzheimer's disease.

Alzheimer's disease (AD), the most common cause of dementia, is a progressive neurodegenerative disorder characterized by cognitive decline, memory impairment, behavioral disturbances, and deterioration in activities of daily living. According to surveys conducted by the Ministry of Health and Welfare in Taiwan, the prevalence of dementia among individuals aged 65 years and older was estimated at 7.86% in 2018, affecting more than 280,000 individuals, and is projected to approach 900,000 by 2065. As the disease progresses, increasing cognitive impairment places substantial medical, social, and economic burdens on patients, caregivers, and healthcare systems. Current pharmacological treatments for Alzheimer's disease provide limited symptomatic benefits and may be associated with adverse effects. Therefore, alternative non-pharmacological interventions that may support cognitive function and improve quality of life are being actively explored.

Experimental studies have suggested that far-infrared (FIR) irradiation may exert beneficial biological effects on mitochondrial function and neuroinflammation. FIR exposure has been reported to enhance mitochondrial oxidative phosphorylation, increase adenosine triphosphate (ATP) production, and improve microglial activity involved in amyloid-β (Aβ) clearance. These mechanisms may potentially delay neurodegeneration associated with Alzheimer's disease progression.

This clinical study is designed as a single-center, randomized, single-blind, parallel-group controlled trial conducted in Taiwan. A total of up to 40 participants with Alzheimer's disease will be enrolled and randomly assigned in a 1:1 ratio to either the active FIR treatment group or the sham-control group. The investigational device is the Yin FuRui De Far-Infrared Therapy Device (Model CE-1889), which generates far-infrared wavelengths ranging from 4 to 14 μm.

Participants in the treatment group will receive daily FIR irradiation therapy using a head-mounted FIR device. FIR irradiation will be applied once daily to the Fengfu (GV16) and Baihui (GV20) acupoints for 30 minutes per site. Participants in the control group will use an identical device with the FIR function disabled. Prior to home use, study personnel will provide device-use training and instructions to participants and their caregivers.

The primary objective of the study is to evaluate the safety of the FIR therapy device. Safety assessments will include monitoring the incidence, severity, and relationship of adverse events (AEs) and serious adverse events (SAEs) associated with the investigational device throughout the study period.

Secondary objectives include evaluating changes in cognitive performance using the Mini-Mental State Examination (MMSE) and assessing mitochondrial function biomarkers obtained from peripheral blood samples. Outcome assessments will be conducted at baseline, Month 1, Month 3, and Month 12.

Safety analyses will be conducted in the Intent-to-Treat (ITT) population. Baseline normal and post-treatment abnormal cases, as well as their proportions, will be summarized separately for the intervention and control groups. The number and incidence rate of adverse events (AEs) and serious adverse events (SAEs) will be calculated and descriptively analyzed. Group comparisons of adverse event incidence will be performed using the Chi-Squared test. Efficacy analyses for MMSE scores and mitochondrial function biomarkers will include paired-sample t tests and independent-sample t tests, as appropriate.

This study aims to determine whether the head-mounted FIR therapy may serve as a safe adjunctive non-pharmacological intervention for patients with Alzheimer's disease to support cognitive function, improve quality of life, reduce caregiver burden, and potentially delay disease progression and institutional care.

Inclusion Criteria:

1. Diagnosed with Alzheimer's disease dementia.
2. Mini-Mental State Examination (MMSE) score between 18 and 24 (inclusive).
3. Currently prescribed and maintained on a stable regimen of anti-dementia medication.
4. No sensory deficits or impairment regarding skin temperature perception.
5. Patient or a Legally Authorized Representative (LAR) must be willing and capable of providing written informed consent prior to enrollment.

Exclusion Criteria:

1. Non-Alzheimer's disease dementia (e.g., vascular dementia, Lewy body dementia, frontotemporal dementia).
2. Known hypersensitivity to heat or light, including the current use of photosensitizing medications.
3. Diminished thermal or heat sensitivity, such as from the concurrent use of analgesics, sedatives, or consumption of alcoholic beverages.
4. Acute injury or acute localized inflammation, including active inflammation, infection, or ulcerated wounds.
5. Concomitant acute venous thrombosis, varicose veins, severe peripheral arterial occlusive disease (Stage III or IV), lymphatic disease, acute rheumatoid arthritis, acute gout, or active fever.
6. Presence of mottled erythema or other abnormal dermatological conditions on the scalp or neck.
7. Localized skin lesions, damage, or open wounds at the device contact sites.
8. Concurrent participation in any other clinical trial.
9. Any other underlying pathological conditions or clinical statuses that, based on medical consensus, would preclude safe participation in the study.
10. Failure or refusal to provide signed informed consent.
11. Inability or unwillingness to comply with the trial protocols, schedules, or required follow-up evaluations.
12. History or presence of hemorrhagic disorders or bleeding-related diseases.

To protect the privacy and confidentiality of the participants in accordance with personal data protection regulations, individual participant data (IPD) will not be publicly shared. The clinical study results will be disseminated exclusively through aggregated data in peer-reviewed scientific publications and official trial registries.