Robust alarm system
View Patent ↗A robust alarm system has an alarm controller adapted to input an alarm trigger and to generate at least one alarm drive signal in response. Alarm subsystems input the alarm drive signal and activate one or more of multiple alarms accordingly. A subsystem function signal provides feedback to the alarm controller as to alarm subsystem integrity. A malfunction indicator is output from the alarm controller in response to a failure within the alarm subsystems.
1. A method of providing audio or visual alarms for a patient monitor, said method executed on one or more processors of said patient monitor to provide patient monitoring functionality including determining measurements for one or more physiological parameters of a patient and when desired, alerting one or more caregivers that said measurements meet one or more predetermined conditions, said method comprising:
outputting a drive signal configured to cause a light source of a noninvasive sensor to emit optical radiation having at least two wavelengths into a tissue site of said patient;
receiving a sensor signal from said sensor, said sensor signal responsive to attenuation of said optical radiation by said tissue site;
electronically determining a physiological parameter measurement responsive to said sensor signal;
generating an alarm trigger responsive to said physiological parameter measurement being beyond a preset limit of said physiological parameter;
determining an availability of a first alarm, said determining comprising monitoring an alarm drive circuit associated with said first alarm to verify said circuit's integrity; and
activating a second alarm in response to said trigger and a determination that said first alarm is unavailable.
2. The method according to claim 1 wherein said determining comprises monitoring an alarm transducer associated with said first alarm to verify said transducer's integrity.
3. A method of providing audio or visual alarms for a patient monitor, said method executed on one or more processors of said patient monitor to provide patient monitoring functionality including determining measurements for one or more physiological parameters of a patient and when desired, alerting one or more caregivers that said measurements meet one or more predetermined conditions, said comprising:
outputting a drive signal configured to cause a light source of a noninvasive sensor to emit optical radiation having at least two wavelengths into a tissue site of said patient;
receiving a sensor signal from said sensor, said sensor signal responsive to attenuation of said optical radiation by said tissue site;
electronically determining a physiological parameter measurement responsive to said sensor signal;
generating an alarm trigger responsive to said physiological parameter measurement being beyond a preset limit of said physiological parameter;
determining an availability of a first alarm;
activating a second alarm in response to said trigger and a determination that said first alarm is unavailable;
distributing at least said a first alarms to a portable instrument; and
distributing at least said second alarms to a docking station adapted to mechanically and electrically interface with said portable instrument.
4. A patient monitor configured to monitor one or more physiological parameters of a patient to alert one or more caregivers when said monitored parameters meet predetermined conditions and configured to include a portable housing dockable with a docking station, comprising:
a portable housing including a sensor output configured to carry a drive signal capable of causing a light source of a physiological sensor to emit optical radiation having at least two wavelengths into tissue of said patient;
said portable housing including an input configured to receive a sensor signal from said sensor, said sensor signal responsive to attenuation of said optical radiation by said tissue;
said portable housing including one or more signal processors configured to determine measurements of said parameters responsive to said sensor signal, and generate an alarm trigger responsive to said measurements;
said portable housing including a first alarm mechanism; and
a docking station configured to mechanically and electrically mate with said portable housing, said docking station including a second alarm mechanism responsive to said trigger and activated based on a determination that said first alarm mechanism is unavailable.
5. The patient monitor according to claim 4 , comprising alarm integrity circuits, each configured to determine an availability of one of said alarm mechanisms.
6. The patient monitor according to claim 5 wherein each of said alarm integrity circuits comprises an acoustic sensor.
7. The patient monitor according to claim 5 wherein each of said alarm integrity circuits comprises a piezoelectric sensor.
8. The patient monitor according to claim 7 wherein each piezoelectric sensor is mechanically coupled to a corresponding alarm mechanism to detect vibrations therefrom.
9. The patient monitor according to claim 5 wherein each of said alarm integrity circuits comprises an ultrasound sensor.
10. A patient monitor configured to monitor one or more physiological parameters of a patient to alert one or more caregivers when said monitored parameters meet predetermined conditions, comprising:
a sensor output configured to carry a drive signal capable of causing a light source of a physiological sensor to emit optical radiation having at least two wavelengths into tissue of said patient;
an input configured to receive a sensor signal from said sensor, said sensor signal responsive to attenuation of said optical radiation by said tissue;
one or more signal processors configured to determine measurements of said parameters responsive to said sensor signal, and generate an alarm trigger responsive to said measurements when said measurements are in an alarm condition;
a first alarm mechanism comprising a driving circuit, an audiovisual device driven by said driving circuit when said alarm trigger is generated during said alarm condition, a drive integrity circuit configured to determine whether said driving circuit is operational, and a device integrity circuit configured to determine whether said audiovisual device is operational; and
a second alarm mechanism responsive to said alarm trigger and activated based on a determination by one or more of said drive integrity circuit or said device integrity circuit that said first alarm mechanism is unavailable.
11. The patient monitor of claim 10 , wherein said first alarm mechanism is incorporated into a portable device and said second alarm mechanism is incorporated into a charging station for said portable device.