1. Device for optical detection of the condition of the joint, comprising: a measuring unit (2) for irradiating light with a part (5) of the body of a subject containing at least one joint, and local detection of attenuation of light in at least one joint and, in at least one other part of the body part (5), the device is further configured to provide information about the condition of at least one joint and detect a response of at least one joint to changes in blood flow caused by reduced by heart contractions of the subject, in comparison with at least one other site. The device according to claim 1, wherein the sampling frequency is at least twice the heart rate of the subject. The device according to any one of claims 1 and 2, in which the sampling frequency is at least 100 Hz, preferably at least 120 Hz, preferably at least 150 Hz, preferably at least 200 Hz, preferably at least 250 Hz, preferably at least 300 Hz, preferably at least 400 Hz. 4. The device according to any one of claims 1 and 2, wherein the device further comprises: a heart rate sensor for detecting a subject's heart rate, the heart rate sensor being connected to the measuring unit (2), so that the sampling frequency is determined based on the subject's heart rate detected by a heart rate sensor. 5. A device according to any one of claims 1 and 2, in which the measuring unit (2) comprises a light source unit (21) capable of emitting light with at least two different wavelengths. Device according to any one of1. Устройство для оптического детектирования состояния сустава, содержащее:измерительный блок (2) для облучения светом части (5) тела субъекта, содержащей, по меньшей мере, один сустав, и локального детектирования ослабления света, по меньшей мере, в одном суставе и, по меньшей мере, на одном другом участке части (5) тела, при этом устройство дополнительно выполнено с возможностью предоставления информации о состоянии, по меньшей мере, одного сустава и обнаружения ответной реакции, по меньше
