This is an exploratory clinical study to evaluate the efficacy and safety of near-infrared light therapeutics in the treatment of mild to moderate Alzheimer's disease.

This experiment adopts a single-center, single-arm research design. All the patients who signed the informed consent were screened, and qualified subjects could only be enrolled to receive NIR therapy. This study plans to enroll 40 patients, all of whom meet the enrollment conditions will receive NIR therapy, and the treatment is arranged to be once a day, once a 30min NIR therapy, 6 times a week. The treatment lasted for 96 weeks, and follow-up and assessment were performed at baseline, 12 weeks, 24 weeks, 36 weeks, 48 weeks, 60 weeks, 72 weeks, 84 weeks, 96 weeks. During the first week of treatment, caregivers will be trained in the use of the NIR device, and after the training is complete, researchers will also provide remote guidance, making visits as needed. Changes in the 96-week ADAS-cog score from baseline were used as the primary endpoint to verify the efficacy and safety of the NIR device.

Inclusion Criteria:

• 50 - 90 years old, no gender limitation;
• Meeting the National Institute on Aging and Alzheimer's Association (2011 NIA-AA) is likely the core clinical diagnostic criteria for Alzheimer's disease;
• The MMSE score is ≥ 12 and ≤ 26;
• The subjects should have primary school education or above and be able to complete the cognitive ability measurement and other tests stipulated in the protocol;
• If taking cognitive-improving medications, the dose must be stable for at least 12 weeks prior to enrollment (stable for at least 4 weeks with psychotropic medications);
• Participants themselves or their guardians voluntarily participate and sign the informed consent.

Exclusion Criteria:

• Any cognitive impairment or dementia not caused by Alzheimer's disease, or co-existing with a serious mental illness (schizophrenia, bipolar disorder, major depression, etc.);
• Currently taking anticoagulant drugs;
• A history of seizures or hemorrhagic stroke within 12 months;
• Allergic to sunlight or visible light or high sensitivity to head and neck skin;
• Severe head trauma or implants (bone nails, bone plates, excision, etc.);
• Malignant tumors;
• Any other medical condition that is not stabilized and adequately controlled (such as serious heart, respiratory, gastrointestinal, or kidney disease), or that the investigator believes may affect patient safety or interfere with the evaluation of the test;
• Persons addicted to alcohol or drugs;
• Women who are pregnant, nursing or planning a pregnancy;
• Participated in other clinical studies within 1 month before participating in this trial;
• Other conditions deemed unsuitable for clinical trial participation by the investigator.