Device for detecting humidity for use with a device for monitoring access to a patient for an installation, with which a liquid is supplied to a patient via a flexible tube and / or a liquid is evacuated from the patient, particularly for vascular access monitoring during an extracorporeal blood treatment, in which the blood of a patient is evacuated from the patient through an arterial flexible tube, which has an arterial cannula, and is supplied to the patient through a venous flexible tube which has a venous puncture cannula, where the device for detecting moisture is configured as a laminar structure to place on the patient's skin, which presents as an humidity sensor an electrically conductive structure, characterized in that the device for detecting moisture is configured as a fabric of non-conductive warp threads and non-conductive weft threads, as well as of conductive warp threads (50) and conductive weft threads (60), where the conductive and non-conductive warp and weft threads are arranged in such a way that the electrically conductive structure is configured.Dispositivo para detectar humedad para la utilización con un dispositivo para la monitorización de un acceso a un paciente para una instalación, con la que mediante un tubo flexible se suministra un líquido a un paciente y/o se evacua un líquido del paciente, particularmente para la monitorización del acceso vascular durante un tratamiento de la sangre extracorpóreo, en el que la sangre de un paciente se evacua del paciente a través de un tubo flexible arterial, que presenta una cánula arterial, y se suministra al paciente a través de un tubo flexible venoso que presenta una cánula de punción venosa, donde el dispositivo para detectar humedad está configurado como una estructura laminar para colocar sobre la piel del paciente, que presenta como sensor de humedad una estructura eléctricamente conductora, caracterizado por que el dispositivo para detectar humedad está configurado como un tejido de hil
