Wearable device for sensing vital signs

#Vital sign measurements are taken to help assess the general physical health of a subject, give clues to possible diseases, and show progress toward recovery. One type of vital sign that is often measured is blood oxygen saturation which is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin in the blood of the subject. Normal blood oxygen saturation levels in humans are 95-100 percent. Blood oxygen saturation levels below 90 percent are considered deficient and are diagnosed as hypoxemia. Blood oxygen saturation levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest.

#Another vital sign that is often measured is blood pressure which is the pressure of circulating blood on the walls of blood vessels. Blood pressure results from the heart pumping blood through the circulatory system and is usually expressed in terms of the systolic pressure (maximum pressure during one heartbeat) over diastolic pressure (minimum pressure in between two heartbeats). Blood pressure is typically measured using an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner to measure the pressure.

#In general terms, the present disclosure relates to a wearable device for sensing vital signs. In one possible configuration, the wearable device provides a technical effect by sensing the blood oxygen saturation level of a subject when attached to a portion of the subject's body that has low blood perfusion and that is ordinarily unable to provide useful data for measuring blood oxygen saturation. In yet another possible configuration, the wearable device provides a technical effect by measuring both the blood oxygen saturation and blood pressure of the subject simultaneously when attached to a portion of the subject's body. Various aspects are described in this disclosure, which include, but are not limited to, the following aspects.

#The following drawing figures, which form a part of this application, are illustrative of the described technology and are not meant to limit the scope of the disclosure in any manner.

#FIG. 1 schematically illustrates a patient monitoring system.

#FIG. 2 schematically illustrates a wearable device for sensing vital signs.

#FIG. 1 is a schematic view of a patient monitoring system 10 that includes a wearable device 100 that can be worn by a subject S to measure one or more vital signs. The wearable device 100 is “wearable” in that it can be applied to a subject's skin and will resist unintentional dislodgement over a specified interval of time

#In one embodiment, the wearable device 100 is used to measure peripheral oxygen saturation (SpO2) of the subject S by calculating a difference in absorption between oxygenated and deoxygenated hemoglobin in the blood of the subject S. In this embodiment, the wearable device 100 can be attached to any area of the body of the subject S including the chest to detect a first set of signals 12 for sensing SpO2. The wearable device 100 amplifies and removes noise from the first set of signals 12 to improve the quality of the SpO2 measurements.

#In another embodiment, the wearable device 100 is used to measure both the SpO2 and blood pressure of the subject S by detecting the first set of signals 12 for sensing SpO2 and detecting a second set of signals 14 for sensing blood pressure. Advantageously, the wearable device 100 can be used to non-invasively measure blood pressure without using an inflatable cuff. Instead, the wearable device 100 is attached to the chest of the subject S. The wearable device 100 simultaneously detects the first and second sets of signals 12, 14 such that the blood pressure and SpO2 of the subject S can be simultaneously measured. In this embodiment, the wearable device 100 both amplifies the first and second sets of signals 12, 14 and removes noise from these signals to improve the quality of the SpO2 and blood pressure measurements.