The Automatic Tongue Diagnosis System (ATDS) was developed to capture tongue images and extract features reliably to assist the diagnosis of TCM practitioners.This project will employ the ATDS verified to extract the tongue features of patients with chronic kidney disease(CKD) including dialysis patients. A TCM indices derived through the non-intrusive tongue diagnosis procedure can provide valuable information for clinical doctors to analyze the current status of a patient and dynamically schedule a treatment plan, facilitating early detection and diagnosis of CKD.

Chronic kidney disease (CKD) is an important global public health problem. According to related literatures, the prevalence of CKD is about 11% .CKD is a progressive disease. If it progresses to end-stage renal disease (ESRD), renal replacement therapy: dialysis and renal transplantation, is required to maintain life. The growing prevalence and progression of chronic kidney disease (CKD) raises concerns about our capacity to manage its economic burden to patients, caregivers, and society. The societal direct and indirect costs of CKD and end-stage renal disease are substantial and increase throughout disease progression. There is significant variability in the evidence about direct and indirect costs attributable to CKD and end-stage renal disease, with the most complete evidence concentrated on direct health care costs of patients with advanced to end-stage CKD.

CKD, also called chronic kidney failure, is described as a sustained reduction in glomerular filtration rate or evidence of structural or functional kidney abnormalities.Chronic kidney disease (CKD) refers to all five stages of kidney damage, from very mild damage in stage 1 to complete kidney failure in stage 5. CKD symptoms include pain, itch(pruritus), peripheral numbness, sleep disturbances, depression, fatigue, nausea and vomiting. Factors that contribute to these symptoms include anaemia, uraemic toxins, reduced renal capacity, chronic disease-related inflammation, and psychological stress associated with long-term illness.If it progresses to end-stage renal disease (ESRD), renal replacement therapy, including hemodialysis, peritoneal dialysis and kidney transplantation, is required to maintain life. Therefore, it is essential to find effective and conservative treatment methods to delay the progression of CKD.

Diagnosis in traditional Chinese medicine (TCM) is based on four procedures, observation, smelling or listening, inquiry, and palpation. Tongue diagnosis, serving as a vital non-invasive tool to provide useful clinical information, plays a pivotal role in TCM. The tongue is considered to reflect the physiological and pathological condition of the body, as well as the degree and progression of disease, through the meridians that connect the tongue to the internal organs.By observing tongue features, TCM practitioners can probe qi-blood, yin-yang disorders which are important in treatment selection and prognosis.Clinically, practitioners observe tongue characteristics, such as tongue color and shape, fur color and thickness, and the amount of saliva, to help deduce the primary pattern of a patient. However, tongue diagnosis is often biased by subjective judgment, which originates from personal experience, knowledge, diagnostic skills, thinking patterns, and color perception/interpretation.The inconsistency of subjective diagnosis can be improved by using the development of validated instruments. The automatic tongue diagnosis system (ATDS) has shown high consistency and can provide objective and reliable information and analysis of tongue features, facilitating doctors in making effective observations and diagnoses of specific diseases.Previous studies have been conducted on exploring the association between tongue characteristics and specific diseases, including rheumatoid arthritis, breastcancer,type 2 diabetes, metabolic syndrome, eczema, dysmenorrhea and functional dyspepsia, gastroesophageal reflux disease.However, to the best of our knowledge, no study has yet been performed on the comprehensive scrutiny of tongue features in patients with CKD using ATDS.

The objectives of this protocol are to apply the noninvasive ATDS to evaluate tongue manifestations in patients with CKD, and to provide valuable information for clinical doctors, which can be used to facilitate the early detection and diagnosis of CKD, to analyze the current status of patients, and to dynamically schedule treatment plans.

Inclusion Criteria:

• age over 20 years old;
• CKD group:CKD stage 3-5 including dialysis patients
• Healthy group: without any medical history

Exclusion Criteria:

• cancer;
• acute infection;
• unable to protrude the tongue stably;
• risk of temporomandibular joint dislocation.

Subjects with CKD stage3-5