Changes in the skin characteristics associated with dehydration and rehydration

A New Method for Detecting Dehydration of the Human Body Using Non-Contact Millimeter Wave Radiometry

Dehydration is a common problem in the aging population. Medical professionals can detect dehydration using either blood or urine tests. This requires experimental tests in the lab as well as urine and blood samples to be obtained from the patients. This paper proposed 100 GHz millimeter wave radiometry for early detection of dehydration. Reflectance measurements were performed on healthy and dehydrated patients of both genders (120 males and 80 females) in the aging population. Based on the cause of dehydration, the patient groups were divided into three categories: (1) patients dehydrated due to less thirst sensation, (2) patients dehydrated due to illnesses (vomiting and diarrhea), and (3) patients dehydrated due to diabetes. Reflectance measurements were performed on eight locations: (1) the palm, (2) the back of the hand, (3) the fingers, (4) the inner wrist, (5) the outer wrist, (6) the volar side of the arm, (7) the dorsal surface of the arm, and (8) the elbow. Skin dehydrated due to vomiting and diarrhea was found to have lower reflectance at all the measurement locations compared with healthy and other types of dehydrated skin. The elbow region showed the highest difference in reflectance between healthy and dehydrated skin. This indicates that radiometric sensitivity is sufficient to detect dehydration in a few seconds. This will reduce the patient's waiting time and the healthcare professional's intervention time as well as allow early treatment of dehydration, thus avoiding admission to hospitals.

Medical Applications of Skin Tissue Dielectric Constant Measurements

Tissue dielectric constant (TDC) values assess certain skin properties that are dependent on multiple factors but mainly on the relative amount of water content within a locally measured tissue volume. Because of the non-invasive nature of these measurements and their ease of use, the method has been widely used in various medically related applications. The goal of this paper was to review and describe the uses and findings of such TDC measurements, considering and including the wide array of medical applications. The review is in part based on information derived from an analysis of published material obtained via literature searches of four major electronic databases and, in part, based on the author's experience with the TDC measurement methods and their various applications and his professional experiences. The databases searched were PubMed, Web of Science, EMBASE, and CINAHL Complete. Based on the initial search criteria, a total of 1257 titles were identified. After removing duplicates and filtering according to relevancy, 160 remained for detailed further review. In some cases, the bibliography of these retrieved articles provided additional sources. The findings demonstrate multiple research and medical uses and applications of TDC measurements, focusing on detecting and quantifying localized edema and lymphedema in multiple target sites. These include the upper and lower extremities, breasts, and trunk as regions involved in medical conditions causing lymphedema. In addition, the findings suggest that TDC evaluations are a convenient, non-invasive method to study and evaluate other conditions impacting skin, including diabetes mellitus and skin wounds or ulcers. Its ability to detect aspects of tissue changes simply and rapidly at almost any anatomical location makes it a useful tool for investigating multiple dermatological conditions and their treatment as future applications of this method.