Patent Description:
In the modern healthcare facility, patients are often kept for extended periods in the emergency unit or an observation ward while test are run and the patient is under observation. Due to cost constraints, patients are not administratively admitted until it is determined that their acuity level qualifies for reimbursement for treatment as an in-patient. As such, the patient may spend an extended period in a space that is not a typical hospital room. From this location, the patient may be transported to other portions of the facility for diagnostic testing.

In some instances, the patient may be in significant discomfort, lack mobility, or be otherwise incapacitated. As such, there may be a need to move the patient to other areas in the facility without transferring the patient to another patient support apparatus or transport device. In other cases, the patient may be relatively mobile and independent. However, limiting the use of different patient support/transport devices reduces labor in cleaning the equipment between patients. In addition, there may be clinical advantages to the patient using a patient support apparatus as a transport, such as to promote the patient's independence. As such, there is a need for a patient support apparatus that is adaptable to multiple modes of transport to fill the various roles the transport equipment may fulfill in the patient intake process.

Patient support apparatus in the form of a mobile vehicle are known. One such vehicle is described in <CIT>, where the modular mobile vehicle with a ready-made vehicle body has an adjustable wheelbase having a wheelbase actuator and a seat module. The vehicle body has at least one motor, at least one rear wheel, two horizontally mounted guiding tubs, a front wheel frame slidably mounted around the two guiding tubes, and is extendably connected with the front wheel frame.

<CIT> discloses a wheelchair for a patient comprising a support frame, at least two main wheels mounted on sides of the support frame and a seat base disposed upon the support frame. Alternatively, a stretcher topping may be mounted upon a laterally slidable storage compartment that may be affixed to the support frame. The seat base and the stretcher topping are configured for selectively raising and lowering the patient between first and second levels. At least one security beam is disposed on the wheelchair and may be configured as a hand hold for steadying the patient when transferring onto and off of the seat base.

According to the present disclosure, a patient support apparatus comprises a base having a variable length, a pair of telescopic lifts extending upwardly from the base, an upper frame supported on the telescopic lifts, the upper frame movable between a chair configuration and a bed configuration, and a pair of independent drive wheels positioned on lateral sides of the base. Each of the drive wheels receives an independent input from a patient supported on the patient support apparatus and responsive to the independent input from the patient to drive each of the drive wheels to move and control the direction of movement of the patient support apparatus over a floor supporting the patient support apparatus. Each drive wheel has a respective independent user input device accessible to the patient and connected to the respective drive wheel, the respective drive wheel responsive to a force applied to the respective user input device associated with the drive wheel.

In some embodiments, the patient support apparatus further comprises a removable barrier assembly coupled to a foot end of the upper frame.

The patient support apparatus may further comprise a removable barrier assembly coupled to a head end of the upper frame.

In some embodiments, a removable barrier assembly comprises a fixed panel and a first movable panel pivotably coupled to the fixed panel providing a barrier at an end of the patient support apparatus, the movable panel movable between a barrier position providing a barrier along a portion of a lateral side of the patient support apparatus and an out of the way position.

In some embodiments, the removable barrier assembly further comprises a second movable panel pivotably coupled to the fixed panel on a side opposite the first movable panel, the second movable panel movable between a barrier position providing a barrier along a portion of the other lateral side of the patient support apparatus and an out of the way position.

In some embodiments, the first and second movable panels nest in their respective out of the way positions.

In some embodiments, a movable panel is pivotable about an axis that is obtuse to the respective barrier surfaces of the end panel and the movable panel.

In some embodiments, the base comprises at least a first extension that is movable relative to a main portion to extend the length of the base.

In some embodiments, the first extension is driven by a powered actuator to move the extension relative to the main portion.

In some embodiments, the base further comprises a second extension that is positioned on a side of the main portion of the base opposite the first extension, the second extension movable relative to the main portion to further extend the length of the base.

In some embodiments, the actuator is operable to simultaneously move both the first and second extensions to extend or retract the length of the base in unison.

In some embodiments, the extensions include casters that engage the floor.

In some embodiments, the casters of each of the extensions and the drive wheels may all engage the floor simultaneously.

In some embodiments, the base includes a pair of actuators that cooperate to extend and retract the first and second extensions.

In some embodiments, at least one of the extensions includes a brake operable to lock the casters of the respective extension to prevent the patient support apparatus from moving over the floor.

In some embodiments, the base includes a foot pedal that is actuable to cause the independent drive wheels to lock or unlock.

In some embodiments, each of the drive wheels is driven by a respective motor.

In some embodiments, the force applied by a user to a respective user input is multiplied by the motor to provide a drive signal that is larger than the input signal.

In some embodiments, each time a user actuates a respective user input the user input signal is applied to the respective drive wheel for an equivalent pulse and the drive wheel speed decays to mimic the action of a wheelchair.

In some embodiments, the user input will receive a signal in either a forward or rear direction and the drive signal of the motor will respond to the direction of the user input to control the speed and direction of the respective drive wheel such that variations in the user inputs to the respective drive wheels vary the relative speed of the respective drive wheels to thereby steer the patient support apparatus.

According to the present disclosure, a patient support apparatus may be movable between a bed configuration and a chair configuration, the patient support apparatus having an upper frame and a lift system for moving the upper frame vertically. The patient support apparatus comprises a base having a main portion supporting the lift system and a pair of extensions that are movable between an extended position when the patient support apparatus is in the bed configuration and a retracted position when the patient support apparatus is in the chair configuration, each of the pair of extensions extending from opposite longitudinal sides of the main portion, the extensions moving in unison to vary the length of the base based on the position of components of the upper frame.

The extensions may move in proportion to one another.

The movement of a first one of the pair of extensions relative to the main portion may be transferred directly to the second one of the pair of extensions to cause the extensions to move in proportion to one another.

The movement of a first one of the pair of extensions may be caused by a drive that is interposed between the main portion and the first one of the pair of extensions, the drive extending and retracting to change the position of the extension relative to the main portion.

A transmission may transfer the movement of the first one of the pair of extensions to the second one of the pair of extensions so that the movement of the drive is transferred through the transmission to the second one of the pair of extensions.

The transmission may be interposed between the first one and the second one of the pair of extensions.

The transmission may comprise a drive rack coupled to the first one of the pair of extensions, a follower rack coupled to the second one of the pair of extensions, and wherein a pinion is interposed between the drive rack and the follower rack to transfer motion of the drive rack to the follower rack to thereby move the second one of the pair of extensions in unison with the first one of the pair of extensions.

The patient support apparatus may further comprise a controller operable to receive position information from drives that control the configuration of the upper frame, and wherein the signals from the position information of the drives that control the configuration of the upper frame are processed by the controller to determine the amount of extension necessary to stabilize the patient support apparatus, the controller causing the pair of extensions to move based on the position information of the drives that control the configuration of the upper frame to stabilize the patient support apparatus.

The controller may be further operable to cause movement of the extensions to prevent interference with components of the upper frame, the decision to move the extensions being dependent on the position of one or more members of the upper frame.

The extensions may be fully extended when the patient support apparatus is in the bed configuration and fully retracted when the patient support apparatus is in the chair configuration.

According to the present disclosure, the patient support apparatus may comprise a drive system including at least two inputs accessible by a user when the patient support apparatus is in the chair configuration, the user inputs providing a signal to the drive system to control the speed and direction of the patient support apparatus over a floor supporting the patient support apparatus based on the composite signal of the at least two inputs.

The at least two inputs may each include a force sensor operable to detect both a direction and magnitude of a force applied to the respective user input.

The drive system may include at least two drive wheels, the drive wheels responsive to the resultant input of the at least two user inputs.

The two user inputs may be operable to cause the patient support apparatus to move forward, make a forward turn, move in reverse, and make a reverse turn.

The user inputs may each be fixed relative to a respective drive wheel.

The user inputs may each be movable with a respective drive wheel.

The patient support apparatus may further comprise a controller which is operable to multiply the user input force to cause the wheels to be driven at a rate that offsets the weight of the patient support apparatus.

The drive system may include a separate drive motor operable to drive respective drive wheel in either a forward or reverse direction.

The present disclosure includes a patient support apparatus <NUM> that is convertible between a bed configuration shown in <FIG> and a chair/wheelchair configuration shown in <FIG>. The patient support apparatus <NUM> includes a base <NUM> that is expandable so that a first extension <NUM> and a second extension <NUM> may be extended from a central portion <NUM> of the base <NUM> to improve the stability of the patient support apparatus <NUM> in the bed configuration. The extensions <NUM> and <NUM> are retractable as shown in <FIG> to provide clearance for a foot section <NUM> when the patient support apparatus <NUM> is moved to the chair configuration. The central portion <NUM> of the base <NUM> supports a lift system <NUM> and a drive system <NUM>, each of which will be discussed in further detail below. The upper frame <NUM> of the patient support apparatus <NUM> includes a head section <NUM>, a seat section <NUM>, and the foot section <NUM>. The head section <NUM> and the foot section <NUM> are pivotable relative to the seat section <NUM>, as will be discussed in further below. The patient support apparatus <NUM> also includes a head end barrier assembly <NUM> and a foot end barrier assembly <NUM>. The barrier assemblies <NUM> and <NUM> are each removable.

Referring to <FIG>, the lift system <NUM> includes lifts embodied as a telescopic head end column <NUM> and a telescopic foot end column <NUM>, each of which is independently extendable so that the upper frame <NUM> may be tilted about a lateral horizontal axis <NUM> as indicated by arrow <NUM>. The lifts <NUM> and <NUM> are each fixed to the central portion <NUM> of the base <NUM> and pivotably coupled to the upper frame <NUM> at separate locations so that extension or retraction of either one of the lifts <NUM> or <NUM> causes pivoting about the respective pivot axes <NUM> or <NUM> at the pivotable connections between the lifts <NUM> and <NUM> to cause tilting of the upper frame <NUM>. In use, the lifts <NUM> and <NUM> will generally cooperate to move in opposite directions to cause any desired tilting of the upper frame <NUM>. The telescopic column lifts <NUM> and <NUM> may be embodied similar to the hi-lo lift units of the CareAssist ® ES Medical Surgical bed from Hill-Rom, Inc. of Batesville, Indiana.

When present, the head end barrier assembly <NUM> includes a head end panel <NUM> that is fixed to the head section <NUM>. A left hand head panel <NUM> is pivotably coupled to the head end panel <NUM> and pivotable about an axis <NUM> to move between the deployed position shown in <FIG> and a retracted position shown in <FIG>. Referring to <FIG>, a right hand head panel <NUM> is pivotably coupled to the panel <NUM> and pivotable about an axis <NUM> to a retracted position similar to the retracted position of panel <NUM> in <FIG>. The axes <NUM> and <NUM> are offset so that there is no interference between panels <NUM> and <NUM> when they are both in their respective retracted positions, but allow the panels <NUM> and <NUM> to offset with the panel <NUM> being positioned outboard of the panel <NUM>.

Referring to <FIG>, the head end barrier assembly <NUM> is secured to the upper frame <NUM> by a tab <NUM> which is received into a receiver <NUM> formed in a head end arm <NUM> of the upper frame <NUM>. The tab <NUM> is formed to include a channel <NUM> which is engaged by a spring-loaded grip <NUM> which has a pawl (not shown) that is positioned in the channel <NUM> when the tab <NUM> is positioned in the receiver <NUM>. The pawl of the grip <NUM> prevents the head end barrier assembly <NUM> from being removed unless a handle <NUM> is actuated, which disengages the pawl and allows the tab <NUM> to be removed from the head end arm <NUM> such that the entire head end barrier assembly <NUM> can be removed from the patient support apparatus <NUM>. Foot end barrier assembly <NUM> is removably coupled to a foot end arm <NUM> (seen in <FIG>) in a manner similar to the way in which head end barrier assembly <NUM> is secured to the head end arm <NUM>.

With further reference to <FIG>, the upper frame <NUM> includes the head end arm <NUM>, the foot end arm <NUM>, a thigh portion <NUM> and a seat portion <NUM>. The seat portion <NUM> is pivotably coupled to the telescopic head end column <NUM> and a telescopic foot end column <NUM> and the movement of the telescopic head end column <NUM> and a telescopic foot end column <NUM> control the overall tilt of the head end arm <NUM>, the foot end arm <NUM>, the thigh portion <NUM> and the seat portion <NUM>. The thigh portion <NUM> is pivotably coupled to the seat portion <NUM> and may be pivoted about an axis <NUM> to adjust the attitude of the thigh portion <NUM> relative to the seat portion <NUM> by a drive <NUM>, shown kinematically in <FIG>.

The head end arm <NUM> is also pivotably about an axis <NUM> and adjustable relative to the seat portion <NUM> as shown in <FIG> with a drive <NUM>. The foot end arm <NUM> is pivotably coupled to the thigh portion <NUM> and pivotable about an axis <NUM> under the power of a drive <NUM>. Using the drives <NUM>, <NUM>, <NUM>, the upper frame <NUM> elements head end arm <NUM>, foot end arm <NUM>, thigh portion <NUM> and seat portion <NUM> may be adjusted between the chair configuration of <FIG> and the bed configuration shown in <FIG>.

Referring again to <FIG>, each of the head end arm <NUM>, the foot end arm <NUM>, the thigh portion <NUM> and the seat portion <NUM> have a width that is narrower than the width of a mattress <NUM> supported on the upper frame <NUM>. The narrow width of the head end arm <NUM>, the foot end arm <NUM>, the thigh portion <NUM> and the seat portion <NUM> reduces the weight of the respective elements and improves the clearance under the mattress <NUM>. The foot end arm <NUM> includes a pair of lateral beams <NUM> and <NUM> that extend from a main portion <NUM> to underlie the mattress <NUM>. The mattress <NUM> is secured to the beams <NUM> and <NUM> by a fastening system that permits the mattress <NUM> to be removably secured to the beams <NUM> and <NUM>, as well as the main portion <NUM> so that the mattress <NUM> may be fixed to the upper frame <NUM>, while still being easily removed. The mattress <NUM> may include substrates (not shown) that provide some mechanical support where there is no underlying portion of the upper frame <NUM> and are secured to the components of the upper frame <NUM> by straps that include hook and loop fasteners.

Similarly to the foot end arm <NUM>, the thigh portion <NUM> includes a main portion <NUM> and a pair of beams <NUM> and <NUM> that extend laterally from the main portion <NUM>. The seat portion <NUM> also includes a main portion <NUM> and a pair of laterally extending beams <NUM> and <NUM>. The head end arm <NUM> includes a main portion <NUM>, a head support <NUM> that is coupled to the main portion <NUM> with the head support <NUM> positioned at an angle relative to the main portion <NUM> to deflect the head end <NUM> of the mattress <NUM> to provide support for a patient's head, regardless of the position of the head end arm <NUM>. The head support <NUM> may be adjustable relative to the main portion <NUM> about an axis to change the angle between the two so that the elevation of the patient's head may be adjusted. The head end arm <NUM> also includes two beams <NUM> and <NUM> that extend from the main portion <NUM> to the patient's right side and two beams <NUM> and <NUM> that extend toward the patient's right side from the main portion <NUM>. The beams <NUM>, <NUM>, <NUM>, and <NUM> also allow the mattress <NUM> to be secured to the head end arm <NUM> while providing reduced weight and clearance under the mattress <NUM>.

Referring now to <FIG>, the drive system <NUM> of the patient support apparatus <NUM> will be explained in further detail. The drive system <NUM> includes a left drive unit <NUM> and a right drive unit <NUM>. Each drive unit <NUM>, <NUM> includes a respective drive wheel <NUM>, <NUM> and a respective user input <NUM>, <NUM>. The user inputs <NUM>, <NUM> are accessible by a patient seated on the patient support apparatus <NUM> when the patient support apparatus <NUM> is in the chair configuration. The user inputs <NUM>, <NUM> allow the user to provide an input to propel the patient support apparatus <NUM> over the floor, similar to the functionality of a wheelchair. The drive system <NUM> may rely entirely upon the force applied by a user to the user inputs <NUM> and <NUM> which is transferred to the drive wheels <NUM>, <NUM> to move the patient support apparatus <NUM>.

Referring to <FIG> and <FIG>, the drive system <NUM> includes respective left drive motor <NUM> and right drive motor <NUM> which react to the user inputs <NUM> and <NUM> to provide a drive signal to the respective drive motors <NUM> and <NUM> which then, in turn, drive the drive wheels <NUM> and <NUM>. The action of the drive motors <NUM> and <NUM> is responsive to the magnitude of the inputs to the user inputs <NUM> and <NUM>, but tend to multiply the force applied by the user so that the force input required by the user is reduced. This allows a user who is not strong enough to actually propel themselves across the floor to be independent. In addition, the magnification of the user inputs <NUM> and <NUM> can be set to offset the weight of the patient support apparatus <NUM> that exceeds the weight of a typical wheelchair, overcoming the difficulties of having a stretcher/bed act as a wheelchair, while still allowing a user to control the motion of the patient support apparatus <NUM> as a typical wheelchair.

Referring to <FIG>, the drive system <NUM> is controlled by a drive controller <NUM> which processes the user inputs <NUM> and <NUM> and provides appropriate drive signals to the motors <NUM> and <NUM> respectively. The motors <NUM> and <NUM>, as well as the drive controller <NUM>, all receive power from a battery module <NUM>. The battery module <NUM> is charged by a power supply <NUM>, which is plugged into mains power <NUM> by a cord <NUM> when the patient support apparatus <NUM> is positioned in fixed location. When the patient support apparatus <NUM> is going to be moved, the cord <NUM> is disconnected from the mains power <NUM> and the patient support apparatus <NUM> is operated by the battery module <NUM>. When the cord <NUM> is connected to mains power <NUM>, the motors <NUM> and <NUM>, as well as the drives <NUM>, <NUM>, and <NUM>, are all powered through the mains power <NUM>. When the cord is disconnected, the battery module <NUM> is used to power the motors <NUM>, <NUM> and drives <NUM>, <NUM>, and <NUM> as well as all of the control circuitry of the patient support apparatus <NUM>.

Referring now to <FIG>, the operation of the extendable base <NUM> includes the coordinated extension of the extensions <NUM> and <NUM> relative to the main portion <NUM> of the base <NUM>. The movement of the extensions <NUM> and <NUM> is caused by the coordinated extension and retraction of two drives <NUM> and <NUM>. Each of the drives <NUM> and <NUM> are fixed at one end to a frame <NUM> of the base <NUM>. The opposite ends of the drives <NUM> and <NUM> are connected to respective beams <NUM> and <NUM> of the extension <NUM>. The beams <NUM> and <NUM> are supported from a cross-bar <NUM> which includes respective yokes <NUM> and <NUM> which engage the beams <NUM> and <NUM> but permit relative movement of the beams <NUM> and <NUM> relative to the cross-bar <NUM>. The cross-bar <NUM> is a component of the frame <NUM> so that the movement of the beams <NUM> and <NUM> is relative to the frame <NUM>.

The beams <NUM> and <NUM> are also engaged with another set of respective yokes <NUM> and <NUM> which are supported from a member <NUM> of the frame <NUM>. The yokes <NUM> and <NUM> cooperate to guide the movement of the beam <NUM> relative to frame <NUM>, while the yokes <NUM> and <NUM> cooperate to guide the movement of beam <NUM> relative to frame <NUM>. Thus, as the drives <NUM> and <NUM> extend, the extension <NUM> is extended relative to main portion <NUM> of the base <NUM> and as the drives <NUM> and <NUM> retract, the extension <NUM> is retracted relative to the main portion <NUM>.

Movement of the beams <NUM> and <NUM> drives <NUM> and <NUM> is also transferred to two beams <NUM> and <NUM> of the extension <NUM> through a pair of transmissions <NUM> and <NUM>. The beam <NUM> is supported on the cross-bar <NUM> by a yoke <NUM> and on a member <NUM> of frame <NUM> by a yoke <NUM>. Similarly, the beam <NUM> is supported on the cross-bar <NUM> by a yoke <NUM> and the member <NUM> by a yoke <NUM>. Thus, the movement of the beams <NUM> and <NUM> relative to the respective yokes <NUM>, <NUM> and <NUM>, <NUM> results in movement of the extension <NUM> relative to the frame <NUM> and main portion <NUM> of the base <NUM>. The transmissions <NUM> and <NUM> cooperate to cause the movement of the extension <NUM> to be coordinated with and proportional to the movement of the extension <NUM>. Each transmission comprises a drive rack <NUM>, a follower rack <NUM>, and a pinion <NUM>. The drive rack <NUM> of each transmission <NUM> and <NUM> is positioned on the driven beams <NUM> and <NUM> of extension <NUM>. The follower rack <NUM> of each transmission <NUM> and <NUM> is positioned on the beams <NUM> and <NUM> of the extension <NUM>. The pinion <NUM> of each transmission <NUM> and <NUM> is positioned between the respective drive rack <NUM> and follower rack <NUM> and supported by the cross-bar <NUM>. The pinion <NUM> is rotatable relative to the cross-bar <NUM> so that as the drive rack <NUM> is moved, teeth <NUM> of the drive rack <NUM> engages teeth <NUM> of the pinion <NUM> to cause the pinion <NUM> to rotate. The teeth <NUM> of the pinion <NUM> engage teeth <NUM> of the follower rack <NUM> such that the motion of the drive rack <NUM> is transferred through the pinion <NUM> to the follower rack <NUM>, causing movement of the beams <NUM> and <NUM>.

In use, the drives <NUM> and <NUM> are controlled by a controller <NUM> (shown in <FIG>) which also controls the drives <NUM>, <NUM>, and <NUM> and the lifts <NUM> and <NUM>. The length of the base <NUM> is controlled by the position of the extensions <NUM> and <NUM>, but is dependent on the configuration of the upper frame <NUM> of the patient support apparatus <NUM>. In use, the extensions <NUM> and <NUM> are positioned to reduce the potential of tipping of the patient support apparatus <NUM> due to a cantilevered load being positioned to far from the center-of-gravity of the patient support apparatus <NUM>. As the head section <NUM> and foot section <NUM> of the patient support apparatus <NUM> are moved to the chair configuration, the potential for a tipping issue to arise is reduced. As such, the extensions <NUM> and <NUM> are controlled based on the position of the head section <NUM> and foot section <NUM>. The controller <NUM> receives inputs to control the position of the head section <NUM> and foot section <NUM> and processes the positions of those components to move the extensions <NUM> and <NUM>. Thus, in operation, the control of the position of the extensions <NUM> and <NUM> is controlled by logic on the controller <NUM>, which, in turn, controls the operation of the drives <NUM> and <NUM>. Each of the drives <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> and the lifts <NUM> and <NUM> have internal sensors (not shown) that provide position information so that the controller <NUM> is able to discern the position of all of the components of the patient support apparatus <NUM> at any time and control the extensions <NUM> and <NUM> to mitigate the potential for tipping of the patient support apparatus <NUM> and to provide clearance for other components as necessary.

The patient support apparatus <NUM> may also include an input pedal <NUM> (seen in <FIG>, for example) that is actuable by a user to choose a mobility mode of the patient support apparatus <NUM>. When present, the pedal <NUM> is supported on a cross-bar <NUM> of the extension <NUM> and is movable to three positions which correspond to three modes: neutral, as shown in <FIG>; brake, which is achieved when a user steps on a pad <NUM> to cause the pedal <NUM> to rotate about its axis <NUM> to position pad <NUM> lower than a pad <NUM>, and steer, which is achieved when user steps on the pad <NUM> and causes the pedal <NUM> to move to the pad <NUM> a to a position that is lower than the pad <NUM>. In the brake mode, the pedal <NUM> actuates a mechanical braking system to lock two casters <NUM> and <NUM> positioned on the extension <NUM> to prevent them from rotating about a horizontal axis and swiveling about a vertical axis, as is known in the art. In the brake mode, a signal is sent to the drive controller <NUM> to cause the drive wheels <NUM> and <NUM> to be immobilized electrically to create two additional points to block the patient support apparatus <NUM> from movement relative to the floor. In the neutral position, the casters <NUM> and <NUM> and the drive wheels <NUM> and <NUM> are all free to move independently to allow the patient support apparatus <NUM> to be moved in a free wheel mode over the floor. In the steer mode, the casters <NUM> and <NUM> are placed in the neutral mode so that they are free to rotate and swivel, but the drive wheels <NUM> and <NUM> are placed under control of the drive controller <NUM> and driven by the motors <NUM> and <NUM> respectively. The patient support apparatus <NUM> includes a sensor assembly (not shown) which is operable to detect the position of the pedal <NUM> and provide that information to the drive controller <NUM>. However, the mechanical structure that changes the mode of the casters <NUM> and <NUM> may be omitted and casters <NUM> and <NUM> may remain free to rotate and swivel in all modes. When the casters <NUM> and <NUM> remain free to rotate and swivel, the locking of the patient support apparatus <NUM> relative to the floor is effected by the drive wheels <NUM> and <NUM> only.

In one example, the user inputs <NUM> and <NUM> may move with the drive wheels <NUM> and <NUM> respectively, but are connected to the drive wheels <NUM> and <NUM> by load sensors (not shown) which sense torque applied to the user inputs <NUM> and <NUM> and the drive controller <NUM> responds to those inputs to mimic the operation of a wheelchair. In another example, the user inputs <NUM> and <NUM> may be fixed relative to the drive wheels <NUM> and <NUM> so that a user must apply a constant force to the user inputs <NUM> and <NUM> to provide a drive signal for the respective drive wheel <NUM> or <NUM>. In this way, the user does not have to move their hands, but only applies a relative force to provide a relative input to the respective drive wheel <NUM> or <NUM>, much like a zero-turn lawn mower or a skid steer apparatus.

In addition to the user inputs <NUM> and <NUM>, which are configured to allow a patient to provide an input to the drive wheels <NUM> and <NUM>, the patient support apparatus <NUM> also includes a caregiver responsive input <NUM> positioned in the head support <NUM>. The caregiver input <NUM> is embodied as a strain gauge that is responsive to pressure applied to the head end panel <NUM> at either an upper grip <NUM> or lower grip <NUM> shown in <FIG>. Pressure on either of the grips <NUM> or <NUM> is sensed by the strain gauge <NUM> and is translated to a drive signal by the drive controller <NUM>. The strain gauge <NUM> is configured to measure torque applied to the grips <NUM> or <NUM> to determine the relative drive speed of each of the drive wheels <NUM> and <NUM> to steer the patient support apparatus <NUM> from the input by the caregiver on the grip <NUM> or <NUM>. The grips <NUM> and <NUM> are used when the patient support apparatus <NUM> is being used to transport the patient in a bed configuration, or when a caregiver has control over the patient support apparatus <NUM>. The strain gauge <NUM> signal is provided by the caregiver applying pressure to the grip <NUM> or grip <NUM> overrides any input applied to the user inputs <NUM> or <NUM> as the caregiver control dominates the patient control of the patient support apparatus <NUM>.

As suggested in <FIG>, a user may apply force in either a forward or rearward direction on the left side of the patient support apparatus <NUM> as indicated by arrow <NUM>. Similarly, the user may apply force in the forward or rearward direction on the left side of the patient support apparatus <NUM> as indicated by arrow <NUM>. The various resulting motions of the patient support apparatus <NUM> are suggested by the arrows <NUM>, <NUM>, <NUM>, and <NUM>. The patient support apparatus <NUM> may make a reverse turn as suggested by arrow <NUM>, a forward turn as suggest by arrow <NUM>, or may move forward as indicated by arrow <NUM> or in reverse as indicated by arrow <NUM>.

In some examples, the patient support apparatus <NUM> may further include a wireless pendant <NUM> which has user inputs typical of a patient support apparatus <NUM> that allows a user to provide inputs to the controller <NUM> wirelessly. As shown diagrammatically in <FIG>, in the illustrative example, the pendant <NUM> may communicate to the controller <NUM> using Bluetooth® based protocol, but other wireless protocols may be employed as well. In still other examples, the pendant <NUM> may be connected to the controller <NUM> by a wired connection. The pendant <NUM> may be inductively charged when it is mounted to another component of the patient support apparatus <NUM>. The pendant <NUM> includes a touchscreen graphical user interface (GUI) and any functions that are limited to an authorized caregiver are not displayed on the GUI until an authorized user is detected to be in the vicinity of the GUI by a locating and tracking system or by a wireless RFID signal from a caregiver identification tag or system. The pendant <NUM> is paired with a particular patient support apparatus <NUM> and if the pendant <NUM> is taken out of range of the patient support apparatus <NUM>, the GUI will provide a message to return the pendant to the appropriate patient support apparatus <NUM>.

A further patient support apparatus <NUM> is shown in <FIG> has an upper frame <NUM> that functions similarly to the upper frame <NUM> discussed above. The patient support apparatus <NUM> utilizes a base <NUM> that does not have any extensions or any ability to extend and retract. The patient support apparatus <NUM> also utilizes a cantilevered lift system <NUM> that is similar to the lift system of the Century CC® bed previously available from Hill-Rom Services, Inc. of Batesville, Indiana. The patient support apparatus <NUM> utilizes a typical brake-steer system, such as that available in the CareAssist® ES bed discussed above.

Referring to <FIG>, patient support apparatus <NUM> is similar to the patient support apparatus <NUM>, but includes a head end structure <NUM> that provides support for accessories as well as a stowable push handle assembly <NUM>. The structure <NUM> includes two posts <NUM> and <NUM> that extend upwardly from the base <NUM> of the patient support apparatus <NUM>. The posts <NUM> and <NUM> have respective arms <NUM>, <NUM> that extend outboard from each of the posts <NUM> and <NUM>. The arms <NUM> and <NUM> each support an oxygen tank holder <NUM> with the arm <NUM> formed to include a receiver <NUM> for receiving an IV pole <NUM>. The arm <NUM> supports a receiver <NUM> for securing a plug <NUM> of a power cord <NUM>. A set of respective push handles <NUM> and <NUM> are supported from the arms <NUM> and <NUM> and are positioned to be used by a caregiver to push the patient support apparatus <NUM> over a floor. The push handles <NUM> and <NUM> are adjustable relative to the arms <NUM> and <NUM> to change the height of grips <NUM> and <NUM>, respectively. The push handles <NUM> and <NUM> are engaged with the arms <NUM> and <NUM> with a ratcheting mechanism (not shown) that allows the push handles <NUM> and <NUM> to be released from the arms <NUM> and <NUM> to rotate about the arms <NUM> and <NUM> to a number of different positions. The release for each of the push handles <NUM> and <NUM> are positioned in the grips <NUM> and <NUM>.

Referring now to <FIG>, a diagrammatic representation of the control system of the patient support apparatus <NUM> is disclosed. The lifts <NUM> and <NUM> and drives <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> are controlled by the controller <NUM> as indicated by the solid arrows. The lifts <NUM> and <NUM> and drives <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> include sensor that are used to determine the position of each and provide that information back to the controller <NUM> as suggested by the dotted lines. The drive controller <NUM> receives inputs from either the caregiver input <NUM> or the left patient input <NUM> and right patient input <NUM>. This information is used to control the operation of the left drive motor <NUM> and right drive motor <NUM>. The controller <NUM> and the motor controller <NUM> each include a processor and a memory device that stores the instructions that are processed by the processor to effect the control of the various s motors, lifts, and drives. It should be understood that the controller <NUM> and motor controller <NUM> may be networked together to share certain data relative to the overall control of the patient support apparatus <NUM>. The pendant <NUM> provides input signals to the controller <NUM> via the wireless connection as suggested by the dotted lines connecting the two. Similarly, the pendant <NUM> may receive inductive charging from the power supply <NUM>.

Claim 1:
A patient support apparatus (<NUM>) comprising
a base (<NUM>) having a variable length;
a pair of telescopic lifts (<NUM>, <NUM>) extending upwardly from the base;
an upper frame (<NUM>) supported on the telescopic lifts (<NUM>, <NUM>), the upper frame (<NUM>) movable between a chair configuration and a bed configuration; and
a pair of independent drive wheels (<NUM>, <NUM>) positioned on lateral sides of the base (<NUM>), each of the drive wheels (<NUM>, <NUM>) receiving an independent input from a patient supported on the patient support apparatus (<NUM>) and responsive to the independent input from the patient to drive each of the drive wheels (<NUM>, <NUM>) to move and control the direction of movement of the patient support apparatus (<NUM>) over a floor supporting the patient support apparatus (<NUM>),
wherein each drive wheel (<NUM>, <NUM>) has a respective independent user input device (<NUM>, <NUM>) accessible to the patient and connected to the respective drive wheel (<NUM>, <NUM>), the respective drive wheel (<NUM>, <NUM>) responsive to a force applied to the respective user input device (<NUM>, <NUM>) associated with the drive wheel (<NUM>, <NUM>).