Patent Application
20200147307
The present invention relates generally to systems and methods for opioid overdose detection and rescue.
Opioid overdose is an acute condition resulting from excessive intake of opioids such as morphine, oxycodone, fentanyl or heroin and was directly implicated in the death of 52,000 Americans in 2016. The sequence of events in death from opioid overdose typically progresses from euphoria to loss of consciousness, respiratory arrest, cardiac arrest and ultimately death.
Naloxone is a potent opioid antagonist that reverses the effects of opioids by restoring consciousness and breathing. The value of Naloxone in reducing death from opioid overdose is widely acknowledged: naloxone preparations in vial, syringe, nasal spray and autoinjector (pre-loaded mechanical injector) formats have been increasingly distributed as a stop-gap measure.
However, in an opioid overdose, the victim is unconscious and current naloxone formulations require an adjacent bystander to correctly diagnose the overdose and administer naloxone to the victim. There are no commercially viable naloxone self-rescue devices available.
This is alarming as most opioids are abused in the privacy of the home where a bystander may not be present. The bystander requirement may be limiting naloxone's life saving potential.
In patients at high risk for opioid overdose in the medical setting, current and accepted medical practice is to continuously monitor vital signs to warn of emergent deterioration of a patient's clinical status. In the setting of an acute overdose, naloxone is then injected by a nurse or physician. Medical vital signs are used as surrogates for respiration (pulse oximetry and respiratory rate as measured by end tidal carbon dioxide or transthoracic impedance) and circulation (blood pressure and EKG).
Recent attempts to develop opioid overdose self-rescue devices and methods (Donnellan, Insler, Olson and Nielsen) all teach towards the mimicry and automation of current and accepted medical practice in which sensors are used to continuously monitor vital signs for aberrancy, which then triggers injection of preloaded naloxone.
However, failure to rescue in the non-medical drug use setting may result from dependence on delicate vital sign sensors normally intended for use by expert medical practitioners in the healthcare setting.
Pulse oximetry is a medical device that indirectly measures respiratory depression by detection of blood oxygenation levels. Hypoxia is typically defined by a reading below 92% beyond which life-threatening anoxia rapidly ensues within three minutes. However, it should be noted that nasal and intramuscular naloxone requires up to ten minutes to provide effect. Hence, a bystander may still be required to provide rescue breaths. Pulse oximetry measurements requires translucency of the body area may be affected by nail polish, vascular disease cold temperature and movement.
End-Tidal Carbon Dioxide (ETCO2, capnography, capnometry) is an extremely sensitive method for detecting respiratory depression in the clinical setting. There are two methods for ETCO2-mainstream and sidestream. Mainstream capnography requires a tight-fitting mask while sidestream capnography utilizes a disposable cannula that is prone to clogging. Successful measurement and interpretation generally requires medical personnel with specific training. Furthermore, portable capnography is high cost with a three-hour battery life.
Other methods such as heart rate, blood pressure and electrocardiography indicate impending physiological collapse and are very likely to require a bystander to administer rescue breaths and chest compressions. Low blood pressure and low cardiac output delay circulation of injected naloxone to the brain.
The present invention is directed to a system and method for detecting impaired consciousness as an early sign of opioid overdose and trigger the administration of preloaded naloxone medicament or alert a third party.
Consciousness or wakefulness of the user is monitored by requiring the user to engage or activate actuator(s) specifically designed to require conscious effort. Involuntary disengagement or release of actuator(s) suggests impaired consciousness and results in an alarm. Should the user fail to respond to this alarm by re-engaging the actuator(s), preloaded naloxone is injected automatically to rescue the unconscious user.
Impaired consciousness can also be detected by failure of user to respond to a series of prompts at timed intervals. The actuator may be a motion detection sensor such as an accelerometer or video camera or may utilize facial recognition technology.
Monitoring for impaired consciousness as a surrogate for opioid overdose is distinct from monitoring of vital signs, which aims to detect respiratory and cardiac depression or arrest. Monitoring for impaired consciousness is strategic as it occurs earlier in the cascade of symptoms associated with opioid overdose, thus providing precious additional time for rescue treatment to take effect. Furthermore, this method alleviates the cost, regulatory requirements and technical complexity of ensuring accurate measurement of vital signs and setting appropriate parameters.
The wearable device contains a battery 104 to power the processor 105 and alarm 106. The alarm may consist of a speaker to emit a loud or unpleasant sound, LED to emit light or a flash of light, vibrator to provide a vibration signal or a combination of these. The device contains buttons to allow the user to turn the device on/off 101 and bypass the alarm to immediately administer naloxone 102. The actuator(s) may be contained in the main device housing 103 and/or contained in a handheld console 110 that may be connected to the wearable device 108 using an electronic cable or via wireless technology. The buttons are designed in such a manner to prevent inadvertently turning off the device or accidentally administer naloxone using the bypass button. The device may contain an automated injector mechanism 107, needle 109 and medicament 111. A variety of automated injector mechanisms can be used for this device including electric powered, gas powered or spring loaded mechanisms, known to those of ordinary skill in the art of automated injectors.
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The present invention is directed to a system and method for using actuator(s) to detect impaired consciousness as an early sign of opioid overdose and to trigger the injection of preloaded naloxone or alert a third party. In the primary embodiment, the invention is designed such that a user with impaired consciousness is no longer able to operate the actuators to provide the required feedback to the device.
The device includes a processor, a user interface, a battery, an actuator(s), an automated injection mechanism and at least one dose of preloaded medicament. The device is not limited to naloxone for reversing opioid toxicity and may be utilized for other toxicities such as organophosphate poisoning in which medicament such as atropine is administered. The device may be worn on an arm or leg and may be handheld or implanted. This system and method is intended to be used from the time of initial drug intake until the pharmacologic effect of drug has decreased such that risk of overdose has passed.
In its primary embodiment, the actuator takes the form of a momentary switch that requires continuous effort on the user to hold in the engaged or depressed position. This switch is preferably in a handheld housing. Continuous engagement or depression of the momentary switch signifies consciousness while disengagement or release of the momentary switch suggests possible impaired consciousness, resulting in an alarm alerting the user to re-engage the switch within a time period to prevent triggering the administration of naloxone.
In another embodiment, the device contains at least two actuators in the form of momentary switches which the user must continuously engage or depress. These switches are also preferably in a handheld housing. This feature reduces false negative type errors in the detection of impaired consciousness.
In yet another embodiment, the device contains an actuator(s) in the form of an intermediate switch(es) which the user must continuously maintain in the intermediate range. These switches are also preferably in a handheld housing. Releasing the switch into the open position or engagement of the switch into the closed position suggests impaired consciousness, resulting in an alarm which requires the user to re-engage the switch into the intermediate position to prevent naloxone injection.
In yet another embodiment, the device utilizes actuator(s) in the form of motion detection sensors including accelerometers or video cameras. These sensors are preferably in a medicament housing or may even employ the user's smartphone sensors. Failure for the actuator(s) to sense movement within a predetermined threshold that monitors the quantity of movement over time results in an alarm which requires user movement to prevent naloxone injection.
In yet another embodiment, the device may challenge the user to confirm his or her consciousness by alerting the user through visual, auditory, tactile or haptic prompts to voluntarily disengage and then re-engage the actuator(s).
In yet another embodiment, the device does not require continuous engagement of the actuator but instead presents the user with a series of prompts at timed intervals, to which failure of the user to provide feedback to the device by intermittently engaging the actuator(s) within a time period may result in an alarm and subsequent injection of naloxone. Time interval between prompts may be constant or variable and may be determined in part by delay of user response to previous prompt, typical pharmacokinetic of drugs of abuse or user input into user interface including drug of abuse, route of abuse, quantity abused, estimated potency and demographic data such as gender, age, weight and height.
The user interface includes button(s) that allow the user to turn the device on and input data, as well as actuator(s) for the user to provide feedback. In some embodiments, the actuators are contained within a handheld console connected by wire or wireless technology to the main housing. In other embodiments, the actuators are contained within the medicament housing.
The device also includes a processor which collects user input from the user interface, stores data into memory, activate alarm and prompts and trigger activation of injector mechanism. The alarm and prompts may be in the form of audio, visual, tactile/haptic, or a combination of the preceding stimuli.
The device may also include an injector mechanism and at least one dose of naloxone medicament. Multiple injector mechanisms and medicament reservoirs have already been described and are available on the market. Typically, these devices use pump propulsion or electrical motor mechanism to drive the needle into tissue prior to injection of medicament. In the described device, medicament may be injected into subcutaneous, muscle or bone tissue or may alternatively be sprayed into the nose. Medicament administered include but are not limited to naloxone, flumazenil or atropine.
The device may also include wireless connectivity with a smartphone to contact a third party should impaired consciousness be detected.
This application claims the benefit of Applicants' prior provisional application, number 62/584,867, filed on Nov. 12, 2017.
