Various documents describing devices in the same technical field are known.
Document US 2010/0099963 A1 (Kilger) describes an apparatus and a method for monitoring a patient's blood oxygen content through a pulse oximeter 16 connected by a cable 25 to a device 50. This document explains that, if the oxygen content falls below a selected level, the apparatus delivers a peripheral nerve stimulation to the patient's wrist in the form of a milliamp current to arouse the patient through a wristband 18 that comprises electrodes 16 connected to the device 50 through a cable 15. Next, the apparatus delivers a signal to a remote monitoring system 42 and checks whether the patient has moved through a movement sensor 32 connected thereto by a third cable. If no patient movement has been detected, the apparatus increases the duration and/or intensity of the stimulus and repeats its application to the wristband 18, also sending a new signal to the remote monitoring system 42. This process is repeated until the movement sensor 32 detects the patient's movement. However, this apparatus has the great disadvantage that the patient's movement is not a dependable verification, and in fact, the wrong decision could be made since the only measurement that should be considered trustworthy is the blood oxygen level indicated by the pulse oximeter. The movement sensor in this apparatus adds cost, weight, and power consumption, especially if intended to be used as a portable equipment, and furthermore it introduces a potential source of failure in an apparatus that should provide maximum safety, as well as the existence of the 3 cables linking the apparatus with the oximeter, the wristband, and the movement sensor. Also, the apparatus does not process heart rate signals to make the decision to generate an electric discharge to the patient. Lastly, the use of a movement sensor does not make it adequate to be used as a portable device by the user who is not sleeping.
Document US 2008/0269832 (Wong et al.) discloses a device designed for fighting sleep apnea, comprising a pulse oximeter 101 located in the earlobe or a finger or toe, connected by means of a cable 103 or in a wireless way to the device 100, which is adapted to be attached around the patient's wrist in order to release electric pulses to two electrodes 113 applied on acupoints on the wrist (LU7) or alternatively on the arm and collarbone. The apparatus is portable and may be battery-operated or connected to a 220V AC power supply through a transformer. The document states that the oximeter 101 may be communicated to the device 100 by wireless Bluetooth®, infrared, or WIFI technology. When the patient's oxygen level falls below a certain level, the circuit releases a voltage pulse or series of pulses to force the patient's reaction. However, the device does not show the advantages of the present invention, since it does not use the heart rate measurement to activate a corrective action in the patient, nor may be used as a portable device when the patient is awake.
Document U.S. Pat. No. 7,789,837 describes an arrangement and method for interrupting obstructive sleep apnea before breathing stops. The arrangement 100 comprises a collar 145 including one or more microphones 125, 130, 135, and 140 to detect the sound of air passing through the patient's respiratory tract 120, which are connected to a control device. The microphone signals verify the patient's normal breathing and, when a respiratory anomaly takes place, for example apnea, the control device delivers an alarm signal to a base station 310 through radiofrequency. The document also mentions the existence of a movement sensor 360 on the patient's chest, sending alarm signals through radiofrequency to the base station if breathing stops. However, the device does not present the advantages of the present invention, since it does not use the heart rate measurement to activate a corrective action in the patient, nor may be used as a portable device when the patient is awake.
Document US 2005/0027207 A1 (Westrbrook et al.) describes a monitoring arrangement to collect and analyze physiological signs in order to detect sleep apnea, which is fixed to the patient's forehead and wherein pulse, blood oxygen values, snoring sounds, and head position are detected and stored. The monitoring arrangement may contain several sensors, such as a pulse oximeter, a microphone to detect snoring sounds, and a position sensor to detect the patient's head position. Although the document mentions that the oximeter delivers blood oxygen level signals and heart rate as well, it does not disclose nor suggest the activation of any stimulation signal for the patient to try to prevent occurrence of the abnormal health event, nor may be used as a portable device when the patient is awake.
Therefore, we conclude that none of the closest documents to the device in the present invention provides a portable apparatus that may be used by a user who is asleep or awake and carrying out normal activities.