Obstruction detection system and method
Systems and methods for detecting a pinch event or obstruction to a movable component of a patient support. In some embodiments, the patient support apparatus may include a control system capable of controlling one or more actuator systems coupled to one or more movable components of the patient support apparatus. The control system may operate according to one or more modes of operation in controlling the actuator system to move a component from a first position to a second position. In one embodiment, the control system may receive sensor feedback indicative of one or more operating characteristics of an actuator system, and analyze the sensor feedback differently in one mode than in another. In one embodiment, the controller may receive sensor feedback indicative of both a speed of a component coupled to the movable component and a current of power supplied to an electric motor of the actuator system.
1. A control system for controlling movement of a component of a patient support from a first position to a second position, said control system comprising:
a sensor configured to provide sensor output indicative of an operating characteristic of the patient support;
a controller operably coupled to the component, the controller operable to obtain the sensor output, the controller configured to detect a pinch event based on a comparison between the sensor output and a pinch event criterion; and
wherein the controller is operable to vary the pinch event criterion based on a direction of movement of the component from the first position to the second position,
wherein the component is a foot section of the patient support, and
wherein the pinch event criterion corresponds to a first pinch event criterion based on the foot section of the patient support moving from a generally horizontal position toward a lowered position, and wherein the pinch event criterion corresponds to a second pinch event criterion different from the first pinch event criterion based on the foot section of the patient support moving from the lowered position toward the generally horizontal position.
2. The control system of claim 1 wherein:
the component of the patent support is an actuator of the patient support;
an electric motor directs movement of the actuator from the first position to the second position;
electric motor circuitry is operable to direct operation of the electric motor; and
the electric motor circuitry is operable to direct supply of power to the electric motor to move the actuator from the first position to the second position.
3. The control system of claim 2 wherein the actuator is coupled to a patient support component of the patient support, and wherein the patient support component is at least one of a foot section of the patient support, a middle section of the patient support, a side rail of the patient support and a frame of the patient support.
4. The control system of claim 2 wherein the operating characteristic of the patient support is a sensed characteristic of power supplied to the electric motor, and comprising a motor sensor configured to provide motor sensor output indicative of the sensed characteristic of power, and wherein the pinch event is detected in response to the motor sensor output being equal to or greater than a first threshold.
5. The control system of claim 2 wherein a motor torque threshold is provided, and wherein the pinch event is detected based on a determination of whether a motor sensor output is indicative of a motor torque being greater than the motor torque threshold.
6. The control system of claim 5 comprising a motor sensor configured to provide the motor sensor output, wherein the motor sensor output is indicative of a speed of the electric motor, wherein the motor torque is determined based on at least one of the speed of the electric motor and the operating characteristic of the patient support.
7. The control system of claim 2 wherein the operating characteristic of the patient support is current supplied to the electric motor.
8. The control system of claim 1 wherein the sensor is a load cell such that the sensor output corresponds to a force applied to the patient support.
9. The control system of claim 1 wherein:
first pinch event criterion is associated with the first position of the component;
second pinch event criterion is associated with the second position of the component;
the controller is operable, with the component in the first position, to conduct a first comparison between the operating characteristic and the first pinch event criterion to detect a pinch event; and
the controller is operable, with the component in the second position, to conduct a second comparison between the operating characteristic and the second pinch event criterion to detect a pinch event.
10. A control system for controlling a component of a patient support, the component being displaceable between a first position and a second position, said control system comprising:
a controller operable to obtain sensor output pertaining to an operating characteristic of the patient support, the controller configured to detect a pinch event based on a comparison between the sensor output and a pinch event criterion; and
wherein the controller is operable to vary the pinch event criterion based on a direction of movement of the component from the first position to the second position,
wherein the component is a foot section of the patient support, and
wherein the pinch event criterion corresponds to a first pinch event criterion based on the foot section of the patient support moving from a generally horizontal position toward a lowered position, and wherein the pinch event criterion corresponds to a second pinch event criterion different from the first pinch event criterion based on the foot section of the patient support moving from the lowered position toward the generally horizontal position.
11. The control system of claim 10 wherein:
the component is an actuator of the patent support;
the actuator is operable to displace a patient support component of the patient support in response to being driven by an electric motor; and
electric motor circuitry operable to direct operation of the electric motor, the electric motor circuitry configured to direct supply of power via a supply output to the electric motor to drive the actuator.
12. The control system of claim 11 wherein a motor torque threshold is provided, and wherein the pinch event is detected based on a determination of whether the sensor output is indicative of a motor torque being greater than the motor torque threshold.
13. The control system of claim 11 wherein the sensor output includes a sensed characteristic of power supplied to the electric motor.
14. The control system of claim 11 wherein:
the pinch event criterion is a first event criterion pertaining to a speed of the electric motor;
the controller is operable to store a second event criterion pertaining to a characteristic of power supplied to the electric motor; and
the controller is operable to detect a pinch event based on a) a comparison between the speed of the electric motor and the first event criterion and b) a comparison between a sensed characteristic of power supplied to the electric motor and the second event criterion.
15. The control system of claim 10 wherein the sensor output corresponds to an external force applied to the patient support.
16. The control system of claim 10 wherein:
first pinch event criterion is associated with the first position of the component;
second pinch event criterion is associated with the second position of the component;
the controller is operable, with the component in the first position, to conduct a first comparison between the sensor output and the first pinch event criterion to detect a pinch event; and
the controller is operable, with the component in the second position, to conduct a second comparison between the sensor output and the second pinch event criterion to detect a pinch event.