Patent Application
20120151678
The present disclosure is related to a patient support apparatus having frame and deck members that move relative to one another. More specifically, the present disclosure is related to a patient support apparatus having sensors which detect when frame and deck members encounter obstructions and a control system that modifies movement of the patient support apparatus based on the information from the sensors.
Patient support apparatuses such as hospital beds, for example, may include frames that move relative to one another, and deck sections that move relative to a frame. The patient support apparatus may include a lower frame, also known as a base frame, and an upper frame which moves relative to the lower frame. The upper frame may be supported on various structures which cause the upper frame to move relative to the lower frame. In some cases, the upper frame is supported on two hydraulic cylinders and is movable relative to the lower frame when the hydraulic cylinders are extended and retracted. In some cases, the upper frame is supported on one or more lift arms that are driven by hydraulic cylinders or motorized actuators. Movement of the lift arms causes the upper frame to move relative to the lower frame. If one of the drives or hydraulic cylinders is driven at a different rate as compared to the other of the drive or hydraulic cylinders, the upper frame may move to a tilt position as compared to the lower frame.
Patient support deck sections are supported on an upper frame and pivotable relative to the upper frame to raise or lower portions of a patient's body. For example, a head deck section may rise relative to the upper frame to incline the patient's torso. In some cases, a thigh deck section that supports a portion of the patient's seat and thighs may also pivot relative to the upper frame. In some cases, a foot deck section may be pivotable relative to a thigh deck section to change the angle between the thigh deck section and the foot deck section. It is also known to have a foot deck section that is extendable and retractable to change the length of the foot deck section.
In some patient support apparatuses such as the Hill-Rom® TotaleCare® bed, for example, the bed is capable of being moved to a position in which a patient may exit, or egress, from the foot end of the bed when the bed has been moved to a chair configuration. This position is generally known as a “chair egress position.” In the chair egress position, the upper frame may be tilted relative to the lower frame, the foot deck section may be pivoted relative to the thigh deck section, and the head deck sections may be pivoted relative to the upper frame. The positions of the various frames and deck sections are monitored by position sensors that provide feedback to a controller to confirm that the frame members and the deck sections are in positions that will not result in contact between frame members and deck section members or between the frame members and deck section members and the floor.
In some cases, potentiometers are connected between two members that move relative to one another. The potentiometers are used to determine the relative movement between the members. For example, a potentiometer may be positioned between a left arm and a lower frame member to determine the amount of movement of the left arm relative to the lower frame. In some cases, a potentiometer is used to measure the length of a hydraulic cylinder or motorized actuator. The amount of movement of the lift arm relative to lower frame, or the length of the cylinder or motorized actuator, are used to determine a relative position of two members of the patient support apparatus. It is also known to use accelerometers to determine the attitude of a frame number or deck section member with the controller utilizing the attitude of the various deck section members and frame members to determine the orientation of the various members relative to one another.
The use of sensors to determine the relative position of frame members and deck section members requires a designer to utilize the kinematic relationship of the various frame members and deck section members to develop logic in the controller to prevent movement to of frame members or deck section members to unacceptable positions. Such relationships are subject to variations in manufacturing tolerances and the accuracy of the sensors used to measure the relationships. These limitations sometimes cause designers of the patient support apparatuses to limit the range of movement of frame members and deck section members to be sure that any movement is outside of any variation which may be expected from sensor limitations or manufacturing variations.
According to one aspect of the present disclosure, a patient support apparatus includes a lower frame, an upper frame, a first sensor positioned on one of the upper frame and the lower frame, and a control system. The upper frame is movable relative to the lower frame. The first sensor has a sensing field and transmits a signal when the first sensor detects a body in the sensing field. The control system includes a controller coordinating movement of the upper frame relative to the lower frame. The controller receives a signal from the first sensor and responds to the first sensor to control movement of the upper frame.
The first sensor may be positioned such that the other of the upper frame and lower frame that the first sensor is not positioned on is the body detected by the first sensor when movement the upper frame relative to the lower frame causes the other of the upper frame and lower frame that the first sensor is not positioned on is in the sensing field.
The controller may modify the movement of the upper frame relative to the lower frame if movement of the upper frame is being requested and the first sensor detects a body in the sensing field.
The patient support apparatus may further comprise a lift system coupled to the control system. When present, the lift system may move the upper frame relative to the lower frame. The control system may control the movement of the lift system. The lift system may be operable to tilt the upper frame relative to the lower frame.
The first sensor may be positioned on the upper frame to detect the floor when the upper frame approaches the floor.
The control system may be operable to stop operation of portions of the patient support apparatus when the first sensor detects a body in the sensing field. In some embodiments, the control system may be operable to change the speed of operation of portions of the patient support apparatus when the first sensor detects a body in the sensing field.
In some embodiments, the first sensor forms a magnetic field. In other embodiments, the first sensor forms a light field.
In some embodiments, the patient support apparatus further comprises a patient support deck section supported on the upper frame and a second sensor positioned on the patient support deck, the patient support deck section movable relative to the upper frame.
In some embodiments, the controller modifies the movement of the upper frame relative to the lower frame if movement of the upper frame is being requested and the first sensor detects a body in the sensing field.
In some embodiments, the controller modifies the movement of the patient support deck section relative to the upper frame if movement of the patient support deck section is being requested and the second sensor detects a body in the sensing field.
According to another aspect of the present disclosure, a patient support apparatus comprises a base frame, an upper frame movable relative to the base frame, and a plurality of deck sections supported on the upper frame. The deck sections are movable relative to the upper frame. At least one deck section that is both pivotable relative to the upper frame and variable in size. The patient support apparatus also includes a first sensor positioned on one of the frames and a second sensor positioned on the at least one deck section that is both pivotable relative to the upper frame and variable in size. The patient support apparatus also includes a control system including a controller coordinating movement of the upper frame relative to the lower frame and coordinating movement of the deck sections relative to the upper frame. The controller receives a signal from the first sensor and responds to the first sensor to control movement of the upper frame if the first sensor detects that the upper frame is proximate the base frame. The controller further receives a signal from the second sensor and responds to the second sensor to control movement of the at least one deck section that is both pivotable relative to the upper frame and variable in size if the second sensor detects that the at least one deck section that is both pivotable relative to the upper frame and variable in size is proximate an obstruction.
The second sensor may detect that the at least one deck section that is both pivotable relative to the upper frame and variable in size is proximate the floor.
The patient support apparatus may further include a first drive to pivot the at least one deck section that is both pivotable relative to the upper frame and variable in size relative to the upper frame. The patient support apparatus may still further include a second drive to extend and retract said at least one deck section that is both pivotable relative to the upper frame and variable in size. Movement of one of the first and second drives may be interrupted if the second sensor detects an obstruction, while the movement of the other of the first and second drives is continued.
In some embodiments, at least one deck section that is both pivotable relative to the upper frame and variable in size is a foot deck section. The foot deck section may continue to retract in size if the second sensor detects an obstruction while the pivoting of the foot deck section is interrupted until the second sensor no longer detects an obstruction.
The obstruction detected may be the floor supporting the patient support apparatus.
The patient support apparatus may further comprise at least two drives that move the upper frame relative to the base frame with the controller controlling operation of the at least two drives. In some embodiments, operation of one of the at least two drives that move the upper frame relative to the base frame is interrupted while the foot deck section continues to retract in size if the second sensor detects an obstruction. In some embodiments, the one of the at least two drives that move the upper frame relative to the base frame resumes operation when the second sensor no longer detects an obstruction.
According to yet another aspect of the present disclosure, a method of controlling movement of portions of a patient support apparatus includes receiving an input signal indicative of a desired position of a member of the patient support apparatus. The method also includes activating a driver to move the member toward the desired position and monitoring a proximity sensor detecting the proximity of the member to an obstruction. The method also includes altering the operation of the driver if the member is determined to be proximate an obstruction.
In some embodiments, the member is variable in size and the patient support apparatus includes a first driver operable to change the size of the member and a second driver to move the member and the method includes the step of changing the size of the member during movement to the desired position. The method may further include varying the speed of the first driver during movement to the desired position. The step of varying the speed may include the step of stopping the first driver during movement to the desired position. The step of varying the speed of the first driver may include varying the speed of the first driver if the proximity sensor detects that the first member is proximate an obstruction.
The step of varying the speed of the first driver may include varying the speed of the first driver if the proximity sensor detects that the member is proximate the floor.
Additional features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of illustrated embodiments exemplifying the best mode of carrying out the invention as presently perceived.
The detailed description of the drawings particularly refers to the accompanying figures in which:
According to the present disclosure a patient support apparatus 10, illustratively embodied as a hospital bed, is movable between a horizontal bed position as shown in
The hospital bed 10 includes a head deck section 34 which is pivotable relative to the upper frame 18 and a seat deck section 36 which is fixed to the upper frame 18. In addition, a thigh deck section 38 is pivotably coupled to the upper frame 18 such that the end 40 of the thigh deck section 38 nearest the foot end 22 of the hospital bed 10 lifts relative to the upper frame 18. A foot deck section 32 is pivotally coupled to the thigh deck section 38 near the end 40 of the thigh deck section 38. The foot deck section 32 includes a base 42 and an extension 44 that moves relative to the base 42 to increase the length of the foot deck section 32. The hospital bed 10 also includes a head panel 28 supported on the upper frame 18 and a footboard 30 supported on the extension 44 of the foot deck section 32. A head side rail 46 is shown in
Referring to a block diagram of a control system 50 that includes the functionality to control movement of the upper frame 18 relative to the lower frame 12, the head deck section 34, the thigh deck section 38, and the foot deck section 32 shown in
The upper frame head lift drive 62 and the upper frame foot lift drive 60 may operate independently to place the upper frame 18 in a tilt position as shown in
The drive system 54 also includes a head section raise drive 68 which moves the head deck section 34 between the lowered position shown in
The drive system 54 also includes a thigh section raise drive 74 that lifts the foot and 40 of the thigh deck section 38 relative to the upper frame 18. The thigh deck section 38 pivots about a pivot 76 that is fixed to the upper frame 18. The drive system 54 also includes a foot deck section raise drive 78 that pivots the foot deck section 32 relative to the thigh deck section 38. The foot deck section 32 is movable from a position where the thigh deck section 38 and foot deck section 32 form a single support surface and a position where the foot deck section 32 has pivoted relative to the thigh deck section 38 Form an angle 80 of approximately 270° as shown in
Each of the drives in the drive system 54 includes a potentiometer that measures the length of the respective drives 60, 62, 68, 74, 78, and 82. With the length of each of the drives 60, 62, 68, 74, 78, and 82 being known, the position of all of the components of the hospital bed 10 may be determined based on the length of the various members, the distance between various pivot points, and various feature dimensions so that the kinematic relationship of all of the frame members and deck section members of the hospital bed 10 can be related in an algorithm used by the controller 52.
The control system 50 further includes a sensor system 56 that includes a number of sensors 84, 86, 88, 90, or 100 that are positioned to detect the proximity of one of the frame members or deck section members to other frame members or deck section members. The sensors 84, 86, 88, 90, or 100 of the sensor system 56 may also detect the proximity of one of the frame members to an external structure such as the floor, for example. In the illustrative embodiment, the sensors 84, 86, 88, 90, or 100 are field sensors which output an electromagnetic signal and monitor for reflection of the emitted signal to determine if the signal is being reflected by an obstruction. A foot section frame sensor 84 is positioned on the lower side of the base 42 of the foot deck section 32 as shown in
The sensor system 56 also includes an upper frame foot sensor 88 and an upper frame head sensor 90, with each of the sensors 88 and 90 being positioned on the lower frame 12 and positioned to detect when the upper frame 18 is proximate the pivot 64 of the foot lift arms 20 or a pivot 92 of the lift arms 24. The sensors 88 and 90 near the respective pivots 64 and 92 in the illustrative embodiment provide a signal to the controller 52 if the upper frame 18 comes is proximate the pivots 64 and 92. The controller 52 responds to the signals from the sensors 88 and 90 by interrupting movement of the upper frame 18 by stopping the operation of the upper frame foot lift drive 60 and upper frame head lift drive 62.
As described above, each of the drives 60, 62, 68, 74, 78, and 82 include potentiometers which permit the controller 52 to monitor the position of the various frame members and deck section members. The sensors 84, 86, 88, and 90 are used by the controller 52 to determine the proximity of the upper frame 18 to the lower frame 12 or the foot deck section 32 to the upper frame 18 and floor 16. Because the sensors 84, 86, 88, and 90 detect the actual presence of the adjacent frame members or the floor 16, the controller 52 may reliably position the upper frame 18 and foot deck section without concern for variations in the accuracy of the potentiometers or manufacturing variances in the production of the frame members and deck section members of the hospital bed 10. This is especially useful when the hospital bed 10 is moved from the horizontal position of
For example, in the illustrative embodiment, the user interface 58 includes a user input device 94 that may be activated by a user to indicate a desire of the user to move the hospital bed 10 to the chair egress position. The user input device 94 may be activated regardless of the position of the upper frame 18 and deck sections 34, 36, 38, and 32. The signal from the user input device 94 is received by the controller 52 and considered by a processor 96 of the controller 52. The processor 96 is coupled to the memory device 98 that includes instructions that cause the processor 96 to operate the drives 60, 62, 68, 74, 78, and 82 to move the foot deck section 32 to the lowered position, the head deck section 34 to the raised position, the thigh deck section 38 to a slightly inclined position, and the upper frame 18 to a reverse tilt position. During the movement to the chair egress position described above, the processor 96 will monitor a footboard sensor 100 to determine if the footboard 30 is present on the foot deck section 32. The footboard 30 must be removed from the foot deck section 32 before the hospital bed 10 will move to the full chair egress position.
As one example, if a user were to activate the user input device 94 when the hospital bed 10 is in the position shown in
In the chair position shown in
The intermittent operation of the foot deck section raise drive 78 will continue until the foot deck section 32 comes in proximity with the upper frame 18 as detected by the sensor 84. If the foot deck section 32 is fully pivoted relative to the thigh deck section 38 and in proximity to the upper frame 18, the upper frame foot lift drive 60 is raised until the sensor 86 no longer detects proximity to the floor 16. Once the foot deck section 32 is fully retracted with the extension 44 retracted relative to the base 42, additional actuation of the user input device 94 will cause the upper frame foot lift to be activated to lower the foot and 22 of the upper frame until the floor 16 is detected by the sensor 86. Utilizing this approach, the height 102 of the thigh deck section 38 relative to the floor 16 is minimized without reliance on the potentiometers of the drives 60, 62, 68, 74, 78, and 82.
In another example, movement of the hospital bed 10 to a tilt position such as that shown in
The controller 52 is also operable to utilize the signal from the foot section end sensor 86 when the hospital bed 10 is moved out of the chair egress position to the horizontal bed position. For example, if a user selects the user input device 104 to move the hospital bed 10 from the chair egress position shown in
It should be understood that while user input devices 94 and 104 have been discussed herein in detail, other user input devices may also be used to move specific frame or deck section members. For example, in some embodiments, the user interface 58 will include user input devices for controlling movement of any of the drives 60, 62, 68, 74, 78, and 82 to extend while other user input devices will control movement of any of the drives 60, 62, 68, 74, 78, and 82 to retract.
The sensors 84, 86, 88, 90, or 100 may be any of several types of sensing devices that detect the presence of a body. For example, the sensors could be Hall effect sensors, contact switches, force sensing devices, photo diode array devices, ultrasonic devices, optical sensors detecting shapes, or other proximity or contact switch devices known in the art. In some embodiments, the sensors 84, 86, 88, 90, or 100 may actually contact an obstruction to sense the proximity of a frame or deck member to the obstruction.
In operation, the controller 52 monitors the potentiometers in the drives 60, 62, 68, 74, 78, and 82, the sensors 84, 86, 88, 90, or 100, and the user input devices 94 and 104. The processor 96 of the controller 52 utilizes instructions stored in memory device 98 to determine when to drive the drives 60, 62, 68, 74, 78, and 82 and in what direction to drive the drives 60, 62, 68, 74, 78, and 82 to achieve a position desired by a user. The controller 52 utilizes the data from potentiometers in the drives 60, 62, 68, 74, 78, and 82, the sensors 84, 86, 88, 90, or 100, and the user input devices 94 and 104 and drives the drives 60, 62, 68, 74, 78, and 82 to the desired position as quickly as possible. If one or more of the sensors 84, 86, 88, 90, or 100 indicates that a member of the frame or deck of the patient support apparatus has encountered an instruction in the form of another member or some external obstruction, such as the floor, for example, the controller 52 modifies operation of one or more of the drives 60, 62, 68, 74, 78, and 82 to prevent contact with the obstruction. The operation of the drives 60, 62, 68, 74, 78, and 82 is optimized to achieve the desired position as quickly as possible by allowing the members to move as near as the obstruction as safely possible without having the member contact the obstruction.
Although the invention has been described with reference to the preferred embodiments, variations and modifications exist within the scope and spirit of the invention as described and defined in the following claims.
