Methods and systems for patient transfer

Abstract

Various methods and systems for patient transfer are provided. In one example, a method for controlling a patient examination table having a plurality of lockable casters includes sequentially adjusting locking of the lockable casters in response to an indication of a patient examination table inversion.

Description

Technical Field

[0001] The embodiments of the subject matter disclosed herein relate to magnetic resonance imaging, and more specifically, to a detachable examination table for medical imaging devices. Background Technology

[0002] Medical imaging technologies, which may include magnetic resonance imaging (MRI), computed tomography (CT), X-rays, etc., are often in high demand in care settings. Typically, multiple stakeholders may share medical imaging equipment and rely on coordinated workflows to increase capacity utilization. Medical imaging systems may utilize detachable examination beds for transferring patients to and from imaging devices (such as MRI scanner hosts). Detachable examination beds allow patients to be prepared for imaging in a dedicated room before entering the imaging room. Furthermore, detachable examination beds can increase patient comfort by reducing bed transfers. In some examples, the use of detachable examination beds can reduce the time interval between completing imaging acquisition for one patient and starting imaging acquisition for the next. For some operators, turning a detachable examination bed during certain patient transfer procedures can be heavy and cumbersome. As an example, reversing maneuvers such as detaching the examination bed from the imaging system after imaging can be challenging. This disclosure provides systems and methods for patient examination beds with lockable casters that can be controlled to assist operators during patient transfer procedures. By improving the transfer process, the amount of time spent in the imaging space is reduced, patient and operator comfort is increased, and overall value is enhanced for multiple stakeholders. Summary of the Invention

[0003] In one embodiment, a method for controlling a patient examination bed with multiple lockable casters includes sequentially adjusting the locking of the lockable casters in response to an instruction to reverse the patient examination bed. In this way, the operator's effort in controlling the patient examination bed can be reduced and patient transfer operations can be made more efficient.

[0004] It should be understood that the above brief description is provided to introduce selected concepts further described in the detailed embodiments in a simplified form. This is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims following the detailed embodiments. Furthermore, the claimed subject matter is not limited to embodiments that address any shortcomings mentioned above or in any part of this disclosure. Attached Figure Description

[0005] This disclosure will be better understood by referring to the following description of non-limiting embodiments, in which:

[0006] Figure 1This is a block diagram of a patient transfer system for a medical imaging apparatus according to an embodiment of this disclosure.

[0007] Figure 2 This is a diagram illustrating patient transfer manipulation using an exemplary removable examination bed known in the art.

[0008] Figure 3 This is a diagram illustrating a first exemplary operation of a patient transfer system according to an embodiment of this disclosure.

[0009] Figure 4 This is a diagram illustrating a second exemplary operation of a patient transfer system according to an embodiment of this disclosure.

[0010] Figure 5 This is a diagram illustrating a third exemplary operation of a patient transfer system according to an embodiment of this disclosure.

[0011] Figure 6 This is a flowchart of a first method for a patient transfer procedure using a patient transfer system according to an embodiment of this disclosure.

[0012] Figure 7 This is a flowchart of a second method for a patient transfer procedure using a patient transfer system according to an embodiment of this disclosure.

[0013] Figure 8 This is a flowchart of a third method for a patient transfer procedure using a patient transfer system according to an embodiment of this disclosure.

[0014] Figure 9 This is a timing diagram illustrating a first exemplary hypothetical operation of a patient transfer system according to an embodiment of the present disclosure.

[0015] Figure 10 This is a timing diagram illustrating a second exemplary hypothetical operation of a patient transfer system according to an embodiment of the present disclosure. Detailed Implementation

[0016] The following description relates to various embodiments for improving the manipulation of detachable examination beds in medical imaging apparatuses. In particular, this disclosure includes a detachable patient examination bed for medical imaging apparatuses such as MRI scanners. The patient examination bed includes lockable casters that can be controlled to assist the operator during difficult manipulation. The patient examination bed may include multiple sensors positioned to detect operator input. In response to received signals instructing operator movement, the system can adjust the locking of one or more casters. Figure 1 A block diagram of an exemplary patient transfer system for a medical imaging device is shown in the figure. Figure 2The diagram illustrates common steering maneuvers known in the prior art for detachable examination tables. With the aid of a patient transfer system, challenging maneuvers can be performed more easily by the operator. Figure 3 , Figure 4 and Figure 5 It shows Figure 1 An exemplary patient transfer operation of the patient transfer system is shown in the figure. Figure 6 , Figure 7 and Figure 8 The document illustrates a method for improving patient examination bed manipulation during patient transfer operations using a patient transfer system. Figure 9 and Figure 10 This is a timing diagram illustrating an exemplary hypothetical operation of a patient transfer system.

[0017] Medical imaging technologies, such as MRI, are powerful tools that are frequently in high demand in the nursing environment. Due to improvements in imaging technology that reduce time spent in the scanner, workflow efficiency, including pre- and post-scan patient manipulation, has been identified as a target area for increasing patient throughput and capacity utilization. Some medical imaging systems use detachable patient examination tables. Detachable examination tables allow patients to be prepared for imaging in the preparation room. After being prepared for imaging, the patient can be transferred to the imaging room on the detachable examination table, docked to the scanner, and scanned while remaining on the detachable examination table. Following this procedure, the patient can be transferred from the imaging room while remaining on the detachable examination table. While detachable examination tables can reduce time between scans by minimizing preparation and other non-imaging operations in the imaging room, the examination tables can be large, heavy, and cumbersome to manipulate.

[0018] Figure 1 A patient transfer system 100 for imaging apparatus 101 is shown. As an example, the imaging system may be a magnetic resonance imaging system for transmitting electromagnetic pulse signals to a patient or subject placed in an imaging space, wherein a static magnetic field is formed to perform a scan to obtain magnetic resonance signals from the subject. One or more images of the subject can be reconstructed based on the magnetic resonance signals thus obtained by the scan. Figure 1 The following figures, as described herein, include axis system 190.

[0019] The patient transfer system 100 includes a detachable examination bed or patient examination bed 102 for placing a patient thereon. The patient examination bed 102 may include a front end 144 having a left front handle 112 and a right front handle 114, and a rear end 146 having a rear handle 118. The patient examination bed 102 may include a plurality of lockable casters rotatably coupled to the patient examination bed 102. As an example, the patient examination bed 102 may include a first caster 104 and a second caster 106 coupled to the front end 144, and a third caster 108 and a fourth caster 110 coupled to the rear end 146. In one example, the first caster 104 and the third caster 108 may be positioned on the left side 182 of the patient examination bed 102, and the second caster 106 and the fourth caster 110 may be positioned on the right side 184 of the patient examination bed 102. The casters may include, for example, wheels that rotate forward or backward along the z-axis and rotate or return about a vertical axis of rotation, and wheel locks for controlling the rotation of the casters. Wheel lock actuators, such as solenoids or stepper motors, can be operated to prevent caster rotation (referred to herein as steering lock) and unlock to allow caster rotation. In some examples, the wheel lock actuator is capable of locking the caster in multiple discrete positions, such as every 15 to 20 degrees, and in other examples, the wheel lock actuator is capable of locking the wheel steering in consecutive positions. In some examples, the wheel lock can be adjusted to reduce rolling friction of the caster wheel. In some examples, the wheel lock may include a fully locked state that can operate as a brake. As an example, a first caster 104 may include a first wheel 120 rotatable about a first vertical axis 128, a first wheel lock 174, and a first actuator 174a. A second caster 106 may include a second wheel 122 rotatable about a second axis 130, a second wheel lock 176, and a second actuator 176a. A third caster 108 may include a third wheel 124 rotatable about a third axis 132, a third wheel lock 178, and a third actuator 178a. The fourth caster 110 may include a fourth wheel 126 capable of rotating about a fourth axis 134, a fourth wheel lock 180, and a fourth actuator 180a.

[0020] Multiple sensors can be positioned on the detachable patient examination bed 102. For example, one or more sensors can be positioned on the patient examination bed 102 to detect user interface forces. As an example, one or more Hall effect sensors or other suitable sensors can be used to determine whether a handle has been used and in which direction the force is applied. For example, a left front handle sensor 148 can be positioned on the left front handle 112, a right front handle sensor 150 can be positioned on the right front handle 114, a rear handle sensor 152 can be positioned on the rear handle 118, and edge sensors 154, 156, and 158 can be positioned differently on the edge of the examination bed 116. In some examples, the patient examination bed 102 may include wheel position sensors, and in other examples, wheel position may not be sensed. As an example, the patient examination bed 102 may include a first wheel position sensor 160, a second wheel position sensor 162, a third wheel position sensor 164, and a fourth wheel position sensor 166 for sensing the position of their respective wheels. The patient examination bed 102 may additionally or alternatively include sensors for detecting acceleration, velocity, and direction of motion, such as an accelerometer 172. The patient transfer system 100 may include an onboard battery 188. The onboard battery 188 may allow various sensors, actuators, and other system components to operate digitally during transport.

[0021] In some examples, the patient transfer system 100 may be controlled via an electronic controller 136. The controller 136 may include a processor 138 operatively connected to a memory 140. The memory 140 may be a non-transitory computer-readable medium and may be configured to store executable instructions (e.g., computer-executable code) that will be processed by the processor 138 to execute one or more routines (such as those described herein). The memory 140 may also be configured to store data received by the processor 138. The controller 136 may be communicatively coupled (e.g., via a wired or wireless connection) to one or more external or remote computing devices, such as a hospital computing system, and may be configured to send and receive various types of information, such as electronic medical record information, procedural information, etc. The controller 136 may also be communicatively coupled to various other components of the patient transfer system 100.

[0022] The controller 136 receives signals from various sensors of the patient examination bed 102 and uses various actuators of the examination bed to adjust the operation of the examination bed based on the received signals and instructions stored in the memory of the controller 136. For example, the movement of the patient examination bed 102 can be controlled via an input device (e.g., a handle sensor, etc.) coupled to the controller 136. The controller 136 can display operating parameters of the patient transfer system 100 via a display that communicates electronically with the system. The controller 136 can receive signals (e.g., electrical signals) via input devices and can adjust the operation of the patient transfer system 100 in response to (e.g., acknowledgment) the received signals.

[0023] As an example, a patient can be moved in and out of the imaging space by moving the patient examination bed 102. For example, the patient can be placed on a removable examination bed in a preparation room before entering the imaging space. One or more technicians or operators can move the patient examination bed 102 by pushing or pulling one or more of the left front handle 112, right front handle 114, and rear handle 118, or otherwise apply force to the examination bed by pushing the edge 116 of the examination bed. For example, a force can be applied along the z-axis to the patient examination bed 102 to produce forward or reverse movement, and a lateral force can be applied along the x-axis to produce left or right turns (e.g., along the x-axis) and deceleration. The casters can rotate based on the force applied to the patient examination bed 102. For example, by pushing the patient examination bed 102 down a long hallway, the casters can rotate to face all in one direction, such as parallel to the z-axis. The rotation of the casters affecting the movement of the patient examination bed 102 can be controlled by selectively applying wheel locks to the wheels.

[0024] As an example, one or more technicians can push the patient examination bed 102 by applying force to the rear handle 118. The rear handle sensor 152 detects force in the -z direction, followed by force in the z+ direction. The corresponding wheel lock outputs of one or more wheel actuators of the patient examination bed 102 can be stored in functions in the controller's memory. For example, the controller can receive force signals and predict that the operator may wish to reverse the direction of travel. In response, the controller can determine, based on system logic, the sequential locking of opposing front and rear wheel pairs, where the input is a force signal and the output is the actuator position of one or more wheel locks. The controller can transmit electrical signals to the actuators of one or more wheel locks to adjust each of the one or more wheels to the corresponding wheel lock output. In some examples, the controller 136 can use an accelerometer 172 to predict operator movement of the patient examination bed 102 by sensing motion, speed, and direction. For example, by sensing the location where the movement begins, the controller 136 can predict the direction of movement or turning and lock one or more casters to assist steering and increase the overall maneuverability of the patient examination bed 102. As another example, controller 136 may use one or more force and / or acceleration sensor signals to receive operator movement of patient examination bed 102 and use input from one or more wheel position sensors to adjust one or more wheel locks.

[0025] Although controller 136 is Figure 1 The diagram is shown for illustrative purposes, but it should be understood that controller 136 may be located at various locations within, around, and / or away from patient examination bed 102. As an example, controller 136 may include multiple devices / modules that may be distributed throughout patient transfer system 100. Therefore, controller 136 may include multiple controllers at various locations within patient transfer system 100. As another example, additionally or alternatively, controller 136 may include one or more devices / modules located outside patient examination bed 102, near patient examination bed 102 (e.g., in the same room), or away from patient examination bed (e.g., a remote server). In each example, the multiple devices / modules may be communicatively coupled via wired and / or wireless connections.

[0026] In some examples, the patient transfer system 100 may include a force assist, also known as hydraulic assist. As an example, the force assist system 142 may include one or more motors coupled to one or more casters and communicating electronically with a controller 136. As an example, the force assist system 142 may use one or more sensors of the system to measure the force applied to one or more handles of the patient examination table 102 and control the speed of the wheels proportional to that force. In one example, the controller 136 may coordinate the force assist system 142 with caster locking control. For example, based on one or more sensor signals, the controller 136 may lock one or more casters and adjust the wheel speed to assist with sharp turns.

[0027] Although the patient examination bed of the MRI system has been described by way of example, it should be understood that the techniques of the present invention can also be useful when applied to other imaging modalities, such as CT, fusion tomography, PET, C-arm angiography, etc. The discussion of the present invention in the context of MRI imaging modalities is provided only as an example of a suitable imaging modality.

[0028] Figure 2 This is a schematic diagram 200 illustrating an exemplary patient transfer operation using a currently available detachable examination bed for medical imaging equipment. As imaging time decreases, the proportion of patient transfer and setup time in the total surgical time increases. The time spent between patients can increase when operators encounter some common patient transfer challenges. The exemplary sequence of patient transfer operations is numbered, and a key is provided to indicate where to lock the casters, which could be useful for improving the maneuverability and ease of use of the examination bed.

[0029] For some users, such as technicians, operators, and nurses, maneuvering an MR detachable examination bed through a medical facility can be challenging. For example, medical facilities may include sharp corners, corridors, and other restrictive transfer pathways. Some detachable examination beds include motion-assistive technologies that help guide the bed's forward and backward movement, but steering-assistive methods are limited. As a first example 202, a patient may be transferred from bed 206 (1) to a patient transfer examination bed or detachable examination bed 204. The operator may pivot (2) the detachable examination bed 204 to enter (3) the patient preparation room 208. After patient preparation, the operator may pivot again (5) to a new position (6) to align with the door of the scanner room 210, and pivot again (7,8,9) to align with the scanner 212 for docking (10). As a second example 214, after a scanning procedure at the scanner 212, the operator may wish to push (13) the detachable examination bed 204 from behind. To exit the scanner room 210, the operator may pivot again (14) the examination bed. When the casters of the removable examination bed 204 are not equipped with wheel locks to prevent rotation at the pivot point, pivoting the examination bed may require considerable force. For example, rear and front casters that can be locked and unlocked via sensor signals located at the front, rear, and side sensors of the removable examination bed can reduce the time spent on patient transfer procedures. Furthermore, if the caster locking and force assistance are coordinated, pivoting the examination bed may be easier for the operator.

[0030] For some stakeholders, initiating the movement of the examination bed from rest can be challenging. As an example, random caster rotation during the initiation of the movement can result in higher push and pull forces at the start of the movement. As a third example 216, the removable examination bed 204 can be brought to the scanner 212, docked (10), and un-docked (11). During the docking movement, all casters will move toward the rear of the examination bed. The operator can pull the removable examination bed 204 in the opposite direction to un-dock, and then all casters will rotate 180 degrees to enable forward movement (12). This movement generates significant friction due to the change in distance between the two points of contact between the casters and the ground. Furthermore, lateral shift or tilting of the examination bed may occur until the random caster rotation stops and matches the direction of pull. The push and pull forces at the start of the movement can vary considerably depending on the orientation of the random caster rotation. In the same way, random caster rotation can also affect the magnitude of the lateral shift experienced by the operator during the initial movement. The variability of random inspection bed motion is exacerbated by the total weight of the inspection bed, increasing the sense of uncontrollability experienced by the operator attempting to manipulate the inspection bed. Sequential release of locks on the casters can reduce random caster rotation and make it possible to start movement from a standstill more predictably. In addition, coordinating the amount of force assisting one or more casters during sequential unlocking can further minimize push and pull forces during undocking and other transfer operations involving movement from a standstill.

[0031] Figure 3 It is used for Figure 1 A diagram illustrating an exemplary patient transfer operation 300 of the patient transfer system 100 of the medical imaging apparatus described herein. In one example, multiple sensors positioned on the handles and other portions of the patient examination bed 102 can sense pushing or pulling of the patient examination bed 102 by one or more operators. Figure 1 The controller 136 in the system processes the data, and the controller can adjust the operation of the patient transfer system 100 in response to the received signals. As an example, the controller can adjust the operation according to the system logic described in Table 1 below.

[0032]

[0033] Table 1 shows the first column indicating scenario numbers. Exemplary scenarios 1 through 4 are given. In other examples, the system logic may describe more or fewer scenarios. The second column indicates the rear handle force sensor signal. For example, an operator pushing or pulling the rear handle 118 may be sensed by the rear handle sensor 152. The third column indicates the left front handle force sensor signal. For example, an operator pushing or pulling the left front handle 112 may be sensed by the left front handle sensor 148. The fourth column indicates the examination bed edge force sensor signal. As an example, an operator pushing or pulling the examination bed edge 116 may be sensed by one of the edge sensors 154, 156, and 158. The sensor signals may indicate lateral forces in the x- or x+ direction and positive or negative forces in the z- or z+ direction, as indicated by the shaft system 190. The fifth column indicates the wheel lock output of one or more casters of the patient transfer system 100. For example, the controller may command steering lock (e.g., Figure 1 Wheel locks 174, 176, 178, and 180 in the middle) prevent one or more of the wheels of the first caster 104, the second caster 106, the third caster 108, and the fourth caster 110 from being locked (e.g., Figure 1 The wheels 120, 122, 124, and 126 in the diagram rotate. The sixth column shows annotations related to the scene.

[0034] As an example, the second scenario in Table 1 is shown at 302. In an exemplary patient transfer operation, the operator pushes the examination bed from the rear handle 118 without the assistance of another technician. To pass through a doorway, the operator can pivot to align the patient examination bed 102 with the doorway. To pivot, the operator pushes the patient transfer system 100 forward and to the right. The rear handle sensor 152 reads the forces applied to the rear handle 118 in the z- and x+ directions. In response to the force signals, the controller can command a steering lock on the wheel corresponding to the second caster 106 of the right front wheel. The steering lock prevents the second caster 106 from rotating, thereby creating a pivot point for the operator to rotate clockwise.

[0035] As an example, the first scenario in Table 1 is shown at 304. In an exemplary patient transfer operation, the operator pushes the examination table from the rear handle 118 without the assistance of another technician. To turn around a corner, the operator can pivot again to align the patient transfer system 100 with the passageway. To pivot, the operator pushes the patient transfer system 100 forward and to the left. The rear handle sensor 152 reads the forces applied to the rear handle 118 along the z- and x-directions. In response to the force signals, the controller can command the steering lock of the wheel corresponding to the first caster 104 of the left front wheel. The steering lock wheel prevents the first caster 104 from rotating, thereby creating a pivot point for the operator to rotate in a counterclockwise direction.

[0036] Additionally or alternatively, an accelerometer 172 may be used (see, for example, see...). Figure 1 The controller can control the scenarios shown in Table 1. As an example, an accelerometer can sense changes in the direction of movement and similarly adjust the casters of the patient transfer system 100. For example, the accelerometer can sense changes in movement from the z-direction to the x-direction. In response to the acceleration signal, the controller can actuate a lock on the wheel of the first caster 104 to provide a pivot point about which the wheel rotates counterclockwise.

[0037] Figure 4 It is used for Figure 1 A diagram illustrating an exemplary patient transfer operation 400 of the patient transfer system 100 of the medical imaging apparatus described herein. For this example, the steering lock of the bed casters 104, 106, 108, and 110 can be commanded, and the accelerometer 172 or a similar sensor can be commanded to read acceleration, velocity, and direction. The sensor signals can be transmitted by a controller (e.g., Figure 1 The controller 136 in the system processes the data and can adjust the operation of the patient transfer system 100 in response to the received signals. In one example, the system can monitor the absolute value of acceleration greater than a threshold. As an example, the controller can adjust the operation according to the system logic described in Table 2 below.

[0038]

[0039] Table 2 shows the first column indicating the scenario number. Exemplary scenarios 5 through 8 are given. In other examples, the system logic may describe more or fewer scenarios. The second column indicates the accelerometer signal. For example, an operator pushing or pulling in the z+ direction (such as by pushing the front handle or pulling the rear handle) can be detected by accelerometer 172. The third column indicates the wheel lock output of one or more casters. For example, the controller may command steering lock (e.g., by actuation) Figure 1 The wheel locks 174, 176, 178, and 180 (or more of them) prevent one or more of the first caster 104, second caster 106, third caster 108, and fourth caster 110 from rotating (e.g., Figure 1 The wheels 120, 122, 124 and 126 in the middle can be rotated or completely locked (e.g., braked).

[0040] As an example, the fifth scenario in Table 2 is shown at 402. In an exemplary patient transfer operation, an operator pushes the patient transfer system 100 from the rear end 146. Accelerometer 172 reads the acceleration in the z-direction. Similarly, an operator can pull the patient examination bed 102 from the front end 144. In response to a signal from the accelerometer, the controller can command a steering lock, for example, one or both of a first caster 104 corresponding to the left front wheel and a second caster 106 corresponding to the right front wheel. The steering lock prevents random rotation of the front casters from driving the patient transfer system 100 in the acceleration direction.

[0041] As an example, scenario six from Table 2 is shown at 404. In an exemplary patient transfer operation, an operator pushes the patient transfer system 100 from the front end 144. Accelerometer 172 reads the acceleration in the z+ direction. Similarly, the operator can pull the patient transfer system 100 from the rear end 146. In response to a signal from the accelerometer, the controller can command a steering lock, for example, one or both of the third caster 108 corresponding to the left rear wheel and the second caster 106 corresponding to the right rear wheel. Steering lock prevents random rotation of the rear casters from driving the patient transfer system 100 in the acceleration direction.

[0042] As another example, scenario seven from Table 2 is shown at 406. In an exemplary patient transfer operation, the operator decelerates and stops the patient transfer system 100. In response to a signal from the accelerometer, the controller can command the unlocking of all caster devices, such as first caster 104, second caster 106, third caster 108, and fourth caster 110. Unlocking all casters allows the operator to change the direction of travel by rotating the casters in the direction of acceleration.

[0043] As an example, scenario eight from Table 2 is shown at 408. In an exemplary patient transfer operation, the operator stops moving the patient transfer system 100 for a duration greater than a threshold time. For example, the duration may be determined by the operator and programmed into the controller. In response to a signal from the accelerometer, the controller may command the locking of all caster devices, such as the first caster 104, the second caster 106, the third caster 108, and the fourth caster 110. In one example, locking all casters may be a braking operation for the patient transfer system 100, such as a complete lock.

[0044] Additionally or alternatively, the scenarios shown in Table 2 may utilize force sensors (e.g., Figure 1The system is controlled by one or more of the rear handle sensor 152 and the left front handle sensor 148. As an example, the sensors can sense changing forces in the z-direction, including decreasing and stopping forces, and the casters can be adjusted similarly to the system logic shown in Table 2. For example, the rear handle sensor 152 can read forces in the z-direction. In response to the force signal, the controller can command the steering to lock one or both of the first and second casters to drive the patient transfer system 100 in the direction of travel.

[0045] Figure 5 It is used for Figure 1 A diagram illustrating an exemplary patient transfer operation 500 of a patient transfer system 100 for a medical imaging apparatus described herein. For this example, lockable casters 104, 106, 108, 110 can be adjusted sequentially from locked to unlocked, or vice versa, thereby delaying caster rotation to minimize random movement of the examination bed. As an example, the locking can be commanded to be adjusted sequentially in response to an indication that the patient examination bed 102 is reversed. This indication may be based on one or more sensors, such as accelerometer 172 or similar sensors sensing acceleration, velocity, and direction. As another example, one or more sensors measuring velocity changes (such as from positive to negative and from negative to positive) may indicate that the patient examination bed 102 is reversed. Additionally or alternatively, one or more sensors detecting user interface forces may indicate that the patient examination bed 102 is reversed. For example, an operator pushing a handle of the patient examination bed 102 may be detected by a handle sensor (e.g., left front handle sensor 148) as a force signal indicating that the patient examination bed 102 is reversed. The sensor signals may be controlled by a controller (e.g., Figure 1 The controller 136 in the system processes the data, and the controller can adjust the operation of the patient transfer system 100 in response to the received signals.

[0046] As a first example, the patient examination bed 102 is docked at 502. The patient examination bed 102 of the patient transfer system 100 can be pushed into the imaging chamber and docked at the scanner 510. As an example, pushing the patient examination bed 102 into the scanner 510 aligns the casters 104, 106, 108, 110 in the direction of travel. The patient examination bed 102 can be stationary, for example, simultaneously docked in the scanner 510 for the duration of the imaging procedure. In some examples, the controller 136 can fully lock or brake the casters in their orientation throughout the imaging procedure.

[0047] As second and third examples, releasing the scanner 510 from its dock when the casters are reversed to the direction of travel can cause random caster rotation. Random caster rotation can produce uncomfortable examination bed manipulation, such as increased tension 504 and tilt 506. The uncontrolled thrust and tension associated with releasing the examination bed from its dock, and more generally, during movement from rest and during reversal of direction, can vary considerably in intensity. As an example, the high friction generated by the reverse caster rotation during reversal of direction can produce increased tension 504. The parallel rotation of the casters to match the direction of travel during reversal of direction can result in uncomfortable examination bed misalignment associated with tilt 506.

[0048] In the fourth example, directional control and pull reduction 508 can be implemented by controlling the rotation of one or more casters during de-docking and other operations. As an example, the system logic of the patient transfer system 100 may include controlling the casters to unlock sequentially in response to an indication of reversing the patient examination bed, starting from a fully locked state (e.g., the examination bed is stationary). For example, the casters may be fully locked. For example, the reversing indication may be based on detecting acceleration or movement in the opposite direction to the most recent movement. As an example, the direction of the docking movement may be stored in the controller's memory, and the controller may command the casters to unlock sequentially upon detecting a de-docking movement (e.g., reverse acceleration). For example, the first caster 104 and the fourth caster 110 may be unlocked first, and after a certain duration, the second caster 106 and the third caster 108 may be unlocked subsequently. As some examples, the duration may be a period of time or a distance.

[0049] As another example, directional control and pull reduction 508 can be achieved by controlling caster rotation during other reversal operations. For example, from the fully unlocked state, the casters can be sequentially locked in response to an indication of patient examination bed reversal (such as an indication by a reverse handle force). In one example, a force applied to the left front handle in the z+ direction (such as from a push) can be stored in the controller's memory, and the casters can be sequentially locked when a force in the z- direction (such as from a pull) is detected on the left front handle. For example, the first caster 104 and the fourth caster 110 can be locked first, and after a first duration, the second caster 106 and the third caster 108 can be locked for a second duration. Caster rotation delay minimizes the variability of push and pull forces and tilt during directional reversal, resulting in more repeatable and desirable performance to reduce effort during challenging manipulations.

[0050] Figure 6 This is a flowchart illustrating an exemplary method 600 of a patient transfer procedure using a patient transfer system for a medical imaging device. For example, the patient transfer system could be used for... Figure 1The patient transfer system 100 of the medical imaging device 101. Method 600 and the remaining methods included herein can be controlled by a controller (such as...) Figure 1 The controller 136) according to the memory stored in the controller (e.g., Figure 1 Instructions in memory 140) combined with one or more inputs (such as from one or more sensors (e.g., located in) Figure 1 The system operates by receiving inputs from the left front handle sensor 148, right front handle sensor 150, rear handle sensor 152, edge sensors 154, 156, and 158, and accelerometer 172 on the patient examination bed 102. The controller can control the actuators of the patient transfer system (e.g., first actuator 174a, second actuator 176a, etc.) in response to sensor signals.

[0051] At point 602, method 600 receives sensor signals from patient transfer system 100. (As mentioned above...) Figure 1 The patient transfer system 100 may employ multiple sensors for detecting movement and / or force on the patient examination bed 102. Sensors for detecting force may be positioned on the right front handle, left handle, and rear handle, and on the edges of the examination bed where the operator can grasp, push, or pull. Additionally or alternatively, sensors for detecting acceleration, velocity, and direction may be positioned on the examination bed. In one example, the sensors of the patient transfer system 100 may continuously monitor changes in the amplitude and direction of the force and acceleration sensors.

[0052] At 604, method 600 determines whether a signal has been detected. In some examples, the controller receives a sensor signal and evaluates whether the signal strength is greater than a background noise level determined for that signal type. For example, signal detection may include an acceleration sensor detecting the absolute value of acceleration greater than a threshold. As another example, signal detection may include a change in velocity from positive to negative or from negative to positive. If a signal is detected, the method checks a marker at 608. If no signal is detected (e.g., not greater than the background noise level), method 600 maintains the current caster settings at 606. For example, if the casters are all locked, the casters may remain locked.

[0053] At 608, method 600 checks the marker. As an example, the marker can be set as part of the fully locked or fully unlocked caster operation, such as the following: Figure 8As shown. For example, all casters can be locked after detecting that the examination bed has decelerated to a stop (e.g., stationary) for more than a threshold duration and a set marker. In another example, a marker can be set after detecting that the patient examination bed has decelerated to a stop for less than a threshold duration. In another example, the marker can indicate the direction of the previous motion signal and / or the previous force signal (e.g., z+, z-, x+, x-) and the status of the casters (e.g., locked or unlocked). In one example, the marker can indicate whether the detected signal is in reverse direction. For example, the controller can detect a reverse handle force. As another example, the controller can detect forward motion, then stationary, then reverse motion, or immediately after reverse motion. As a further example, the controller can detect motion in the opposite direction to the most recent motion. In another example, the marker can indicate whether the examination bed has docked with the imaging system.

[0054] At 610, if a flag is received, method 600 continues to 612. If no flag is received, method 600 continues to 620.

[0055] At position 612, method 600 can optionally reduce the force assistance. (See regarding...) Figure 1 The patient transfer system may include a force-assist system (e.g., force-assist system 142). During patient transport, the force-assist system reduces the effort required by the operator to push and pull the examination table. However, during reversal, when the casters can rotate randomly to align with the direction of travel, the force assist can increase the intensity of the push and pull forces associated with the random caster rotation. Temporarily reducing the responsiveness of the force assist can reduce the magnitude of the push and pull forces and lateral deviation during the initial movement. As an example, method 600 may include reducing the force assist for a first duration based on an indication that the reversal is less than a first threshold, and reducing the force assist for a second duration based on an indication that the reversal is greater than the first threshold. For example, the indication for reversal may be the force on the handle, and the first threshold is the magnitude of the force on the handle. As another example, the first duration may be the duration determined for unlocking a first set of casters. The second duration may be the duration determined for unlocking all four casters. As another example, the second duration may be the estimated amount of time it takes for all casters to rotate to the direction of travel. In some examples, such as patient transfer systems without a force-assist system, method 600 may skip 612.

[0056] At 614, method 600 includes sequentially adjusting the locking of the casters. In one example, method 600 may determine, based on a mark at 608, whether the command is to unlock sequentially from the locking sequence or to lock sequentially from the unlocking sequence. For example, the method may include unlocking one of the front casters and simultaneously unlocking the rear caster located on the opposite side of the examination bed. After a threshold duration, the method may include unlocking the other front caster and simultaneously unlocking the other rear caster. As some examples, the duration may be a period of time or a distance. For example, a duration for aligning casters in opposite directions, determined empirically, may be programmed into the controller. As another example, a travel distance determined for aligning casters in opposite directions may be programmed into the controller. As another example, adjusting the locking of the casters may include locking the left front caster and simultaneously locking the rear caster on the opposite side of the examination bed. After a first threshold duration, method 600 may include locking the right front caster for a second threshold duration and simultaneously locking the other rear caster.

[0057] At 616, this method can restore the force assist to the default or nominal settings.

[0058] At position 618, this method can remove the marker.

[0059] Returning to 610, if no marker is received, method 600 can determine at 620 whether the sensor signal is a force signal. If the sensor signal is a force signal, method 600 evaluates the force signal at 622. Force signal evaluation is performed at... Figure 7 Detailed description follows. If the sensor signal is not a force signal, method 600 continues to 624 to evaluate the acceleration signal. Acceleration signal evaluation is described in... Figure 8 A more detailed description is provided below.

[0060] Method 600 can then be reversed. For example, method 600 can be repeated at different times throughout the patient transfer process.

[0061] Figure 7 This is a flowchart illustrating an exemplary method 700 of a patient transfer procedure using a patient transfer system for a medical imaging device. For example, the patient transfer system could be used for... Figure 1 The patient transfer system 100 of the medical imaging device 101. Method 700 may be an exemplary method for evaluating force signals received by one or more force sensors of a plurality of force sensors positioned on a patient examination bed and adjusting the locking of one or more lockable casters of the patient examination bed in response to the received signals.

[0062] At 702, method 700 determines whether a force signal is sensed at the rear handle sensor and at least one of the left front, right front, and examination bed edge. As an example, force sensor signals originating from the rear handle and another examination bed location may indicate that more than one operator is turning the examination bed, such as in a multi-operator condition. As another example, force signals originating from the rear handle and another examination bed location (e.g., multiple user interface forces) may indicate that an operator is correcting the examination bed's travel direction. If method 700 determines that a force signal is sensed at the rear handle sensor and another handle or examination bed edge, method 700 unlocks all casters at 704. For example, unlocking all casters allows them to rotate freely until the examination bed's travel direction is corrected.

[0063] Optionally, method 700 may continue to 706. At 706, method 700 determines whether the force signal is greater than a threshold force. As an example, the threshold force may be preset to a level that triggers the use of the force-assisted system. In an example where the patient transfer system does not include a force-assisted system, method 700 may skip 706. If the force signal is greater than the threshold force, method 700 continues to 708. If the force signal is not greater than the threshold force, the method may return.

[0064] Optionally, at 708, method 700 may add a force assist proportional to the force signal to increase the speed of the wheels coupled to the patient examination bed. For example, the force assist will be more forceful if the operator pushes harder than if the operator pushes less hard. From 708, the method may return.

[0065] If method 700 determines that no force signal is sensed at the rear handle sensor and the edge of the other handle or examination bed, then method 700 evaluates the force from the rear handle at 705. Although an example of evaluating the rear handle force signal is given in method 700, it is understood that the front handle force signal can be evaluated similarly.

[0066] At 712, the method determines whether the rear handle force signal indicates right turn. In one example, a force in the z- direction from the rear sensor may instruct the operator to push the patient examination bed forward from the rear handle. A force in the z+ direction from the rear sensor may instruct the operator to pull the patient examination bed backward from the rear handle. An operator pushing the trolley to the right from the rear handle may generate force signals in both the z- and x+ directions. An operator pulling the trolley to the right from the rear handle may generate force signals in both the x- and z+ directions. If the rear handle force signal indicates right turn, the method proceeds to 714. If the rear handle force signal does not indicate right turn, the method proceeds to 720.

[0067] At point 714, method 700 can lock the right front caster. For example, the controller can send an electrical pulse to the locking actuator, thereby locking the caster in its current orientation and preventing it from rotating. Locking the right front caster creates a pivot point around which the operator can more easily rotate the cart.

[0068] Optionally, method 700 may continue to 716. At 716, method 700 determines whether the force signal is greater than a second threshold. In an example where the patient transfer system does not include a force-assisted system, method 700 may skip 716. If the force signal is greater than the second threshold, method 700 continues to 718. If the force signal is not greater than the second threshold, the method may return.

[0069] Optionally, at 718, method 700 may add a force assist proportional to the force signal to increase the speed of the wheels coupled to the patient examination bed. From 718, the method may return.

[0070] At 720, the method determines whether the rear handle force signal indicates a left turn. An operator pushing the cart to the left from the rear handle can generate force signals in the z- and x- directions. An operator pulling the cart to the left from the rear handle can generate force signals in the x+ and z+ directions. If the rear handle force signal indicates a left turn, the method continues to 722. If the rear handle force signal does not indicate a left turn, the method continues to 724, where the acceleration sensor signal is evaluated. The acceleration signal evaluation is performed in... Figure 8 As shown in the image.

[0071] At point 722, method 700 can lock the left front caster. For example, the controller can send an electrical pulse to the locking actuator, thereby locking the caster in its current orientation and preventing it from rotating. Locking the left front caster creates a pivot point around which the operator can more easily rotate the cart.

[0072] Optionally, method 700 may continue to 716. At 716, method 700 determines whether the force signal is greater than a second threshold. In an example where the patient transfer system does not include a force-assisted system, method 700 may skip 716. If the force signal is greater than the second threshold, method 700 continues to 718. If the force signal is not greater than the second threshold, the method may return.

[0073] Optionally, at 718, method 700 may add a force assist proportional to the force signal to increase the speed of the wheels coupled to the patient examination bed. From 718, the method may return.

[0074] Figure 8 This is a flowchart illustrating an exemplary method 800 of a patient transfer procedure using a patient transfer system for a medical imaging device. For example, the patient transfer system could be used for... Figure 1The patient transfer system 100 of the medical imaging device 101. Method 800 may be an exemplary method for evaluating acceleration signals received by an acceleration sensor (e.g., an accelerometer) positioned on a patient examination bed and adjusting the locking of one or more lockable casters of the patient examination bed in response to the received signals.

[0075] At 802, method 800 determines whether the acceleration signal is in the z-direction. In one example, a signal in the z-direction could indicate a positive push from the rear handle. If method 800 detects acceleration in the z-direction, the method proceeds to 804.

[0076] At 804, method 800 may lock one or both of the right front caster and the left caster and unlock the front and rear casters and the left caster. In one example, the lock may be a steering lock to prevent the casters from rotating about their axis of rotation. Steering lock of one or both of the right front caster and the left caster while pushing the trolley from the rear handle may have the advantage of helping the operator maintain a straight line and a positive direction of travel, such as while traveling through a long and straight corridor. The method can be reversed.

[0077] At 806, method 800 determines whether the acceleration signal is in the z+ direction. In one example, an acceleration signal in the z+ direction could indicate a forward push from the front handle. If method 800 detects acceleration in the z+ direction, the method proceeds to 808. If method 800 does not detect acceleration in the z+ direction, the method proceeds to 810.

[0078] At 808, method 800 may lock one or both of the right rear caster and the left rear caster and unlock the front and rear casters and the left caster. In one example, the lock may be a steering lock to prevent the casters from rotating about their axis of rotation. Steering lock of one or both of the right rear caster and the left rear caster while pushing the cart from the front handle may have the advantage of helping the operator maintain a straight line and a positive direction of travel. The method can be reversed.

[0079] At 810, the method can determine whether the acceleration signal indicates deceleration to a stop for a duration greater than a threshold. In one example, deceleration to a stop for a duration greater than the threshold can signal to the operator that the device is docked at the imaging system. In one example, the threshold duration can be a specific duration. A stop for a duration less than the threshold can indicate to the operator that the device plans to reverse direction. If method 800 detects deceleration to a stop for a duration less than the threshold, the method proceeds to 812. If method 800 detects deceleration to a stop for a duration greater than the threshold, the method proceeds to 818.

[0080] At 812, method 800 unlocks all casters. In one example, if a direction change instruction is received immediately afterwards, unlocking can enable accelerated direction change operation. A marker can be set at 814 to indicate that all casters are unlocked. Additionally or alternatively, the marker can indicate the direction of travel immediately preceding the deceleration to stop event. From 814, method 800 can return.

[0081] If the inspection bed remains stationary for longer than a threshold duration, then at 818, method 800 may lock all casters. In one example, the method may include fully locking (e.g., braking) the casters. A marker may be set at 820 to indicate that all casters are locked. Additionally or alternatively, the marker may indicate the direction of travel immediately preceding the deceleration to stop event. From 820, method 800 may return.

[0082] Figure 9 and Figure 10 This is a timing diagram illustrating a hypothetical operation of a patient transfer procedure using a patient transfer system. The methods used for patient transfer can be compared with those described above. Figure 6 , Figure 7 and Figure 8 The methods described in methods 600, 700, and 800 are the same as or similar. The patient transfer system can be used with... Figure 1 The patient transfer system 100 shown is identical or similar, including a detachable examination bed with lockable casters. Instructions for performing the methods described in timing diagrams 900 and 1000 can be executed by a controller (e.g., controller 136) based on instructions stored in the controller's memory and in conjunction with sensor feedback received from components of the patient transfer system, including those positioned above regarding… Figure 1 The patient examination bed is equipped with accelerometers and force sensors (e.g., accelerometer 172, left front handle sensor 148, right front handle sensor 150, rear handle sensor 152, and edge sensors 154, 156, 158). In a hypothetical example, the controller determines whether a sensor signal has been indicated and, in response to the indication, adjusts the locking of one or more casters of the examination bed, and may add a certain amount of force assistance. Regarding... Figure 9 Sequence diagram 900 illustrates the first operation, in which the casters of the patient examination bed are sequentially unlocked in response to an instruction to reverse the patient examination bed. Regarding... Figure 10 Timing diagram 1000 illustrates the second operation, in which the casters of the patient examination bed are simultaneously unlocked in response to the detection of multiple user interface forces. The horizontal axis (x-axis) represents time, and the vertical markers t0 to t6 respectively identify… Figure 9 and Figure 10 The relevant times used to control the patient transfer system in time series diagrams 900 and 1000.

[0083] Timing diagram 900 shows graphs 902, 903, 904, 906, 908, 910, 912, 914, and 916, which illustrate the component and / or control settings of the patient transfer system over time. Graph 902 indicates the rear handle force in the z-direction. The rear handle force is detected by a sensor positioned on the rear handle of the patient examination bed. The rear handle force can indicate z- (e.g., pushing the rear handle) or z+ (e.g., pulling the rear handle). Graph 903 indicates the left front handle force in the z-direction. The left front handle force is detected by a sensor positioned on the left front handle of the patient examination bed. The left front handle force can indicate z+ (e.g., pushing the left front handle) or z- (e.g., pulling the left front handle). Threshold positive force 918 and threshold negative force 920 are shown in graphs 902 and 903. In response to a force signal greater than the force threshold, the controller can activate force assistance to increase the wheel speed proportionally to the force signal. Curve 904 indicates the acceleration in the z-direction detected by an accelerometer positioned on the patient examination bed. Curve 906 indicates the status of the unlockable or lockable right front caster. Curve 908 indicates the status of the unlockable or lockable left front caster. Curve 910 indicates the status of the unlockable or lockable left rear caster. Curve 912 indicates the status of the unlockable or lockable right rear caster. Curve 914 indicates the open or closed marking conditions. Curve 916 indicates force assistance. Force assistance is temporarily reduced in response to an indication of examination bed reversal (such as detection of a reverse handle force). If the reversal indication is less than one of a threshold positive force 918 and a threshold negative force 920, the duration of the force assistance reduction can be a shorter first duration set for unlocking the first pair of casters. If the reversal indication is greater than one of a threshold positive force 918 and a threshold negative force 920, the duration of the force assistance reduction can be a longer second duration set for rotating all casters in the direction of travel. Curves 902, 903, 904, and 916 increase upwards along the y-axis.

[0084] At t0, the rear handle signal indicates the force in the z-direction in curve 902. The acceleration signal indicates the acceleration in the z-direction in curve 904. The patient examination bed is controlled such that the right and left front casters are locked, for example, to prevent rotation, and the right and left rear casters are unlocked, for example, to allow free rotation about the vertical axis of rotation. Locking in this way assists the operator controlling the patient examination bed from the rear to more easily move forward and in a straight line. The controller applies a moderate amount of force assistance.

[0085] From t0 to t1, the operator pushes the examination table from the rear handle in the direction of the MRI scanner. The operator slows down as they approach the scanner, preparing to stop at the imaging unit. The rear handle sensor indicates the reduced force in the z-direction in graph 902. The accelerometer detects the deceleration in the z-direction in graph 904. The front casters remain locked. Force assistance decreases proportionally to the reduced rear handle force signal.

[0086] At t1, the patient examination bed is positioned, for example, docked, at the MRI scanner. Force sensors indicate that no positive or negative force (z = 0) is applied to the rear or front handle in curves 902 and 903, respectively. No acceleration is detected in curve 904 (z = 0). Force assistance is off in curve 916.

[0087] From t1 to t2, in response to a sensor indication to decelerate to a stop, the right and left front casters are adjusted from locked to unlocked in curves 906 and 908, respectively. At t2, after a threshold duration (e.g., t1 to t2), all casters are adjusted from unlocked to locked, and a marker is set in curve 914. As an example, the threshold duration can be set by the operator of the patient transfer system. As an example, the threshold duration is 30 seconds. The marker is stored in the controller's memory, including the status of the casters (e.g., all locked) and the status of the examination bed (e.g., docked at the scanner). In other examples, the marker may indicate the last direction of force or acceleration.

[0088] From t2 to t3, the patient examination bed remains stationary while the patient undergoes the imaging procedure. In some examples, all casters remain locked. There is no indication of the force or acceleration applied to the examination bed handles.

[0089] At t3, the operator pushes the left front handle in curve 903, instructing the patient examination bed to reverse. The indication of examination bed reversal is less than the positive force threshold 918. From t3 to t4, in response to receiving the force sensor signal, the controller checks the marker. The marker indicates that the examination bed is stopped and all casters are locked.

[0090] At t4, the force-assisted reduction is set to a shorter first duration. In response to the marking indication, the casters are unlocked sequentially. The right front caster in curve 906 and the left rear caster in curve 910 are unlocked first. From t4 to t5, the operator pushes the left front handle, and the force signal increases in the z+ direction. The acceleration signal detects the increased movement in the z+ direction as the patient examination table is released from the medical imaging device. No movement in the x+ or x- directions is detected when the operator pushes the examination table from the imaging system.

[0091] At t5, after a duration, for example, from t4 to t5, the left front caster in curve 908 and the right rear caster in curve 912 are unlocked. Force assistance returns to the nominal setting. By delaying caster rotation during the initial inspection bed movement, the disengagement procedure is smooth and has minimal tilt. The left front sensor signal indicates that the force on the left front handle in the z+ direction exceeds the positive force threshold 918.

[0092] From t5 to t6, in response to the detection of a force signal greater than the threshold, the force assistance increases proportionally to the force signal. The acceleration signal of the patient examination bed increases with the application of force assistance and the force on the left anterior handle platform.

[0093] Figure 10 The timing diagram 1000 illustrates the use of patient transfer systems (such as those related to...) Figure 1 The illustrated patient transfer system 1000 presents a second hypothetical example of a method for transferring a patient. Timing diagram 1000 shows graphs 1002, 1003, 1004, 1006, 1008, 1010, 1012, 1014, and 1016, illustrating the component and / or control settings of the patient transfer system over time. Graphs 1002 and 1003 indicate the examination bed edge forces in the x and z directions, respectively. The examination bed edge forces are detected by sensors positioned on the edges of the patient examination bed. The examination bed edge forces may indicate x- (e.g., pushing to the right) or x+ (e.g., pushing to the left). The examination bed edge forces may indicate z- (e.g., pushing the rear handle) or z+ (e.g., pushing the front handle). Graph 1004 indicates the left front handle force in the z direction. The left front handle force is detected by sensors positioned on the left front handle of the patient examination bed. The force applied to the left front handle can indicate z+ (e.g., pushing the left front handle) or z- (e.g., pulling the left front handle). Graph 1006 indicates the acceleration in the z-direction detected by an accelerometer positioned on the patient examination table. Graph 1008 indicates the unlockable or locked status of the right front caster. Graph 1010 indicates the unlockable or locked status of the left front caster. Graph 1012 indicates the unlockable or locked status of the left rear caster. Graph 1014 indicates the unlockable or locked status of the right rear caster. Graph 1016 indicates the open or closed marking conditions. Graphs 1002, 1004, and 1006 increase upwards along the y-axis.

[0094] At t0, the patient examination bed is stationary in the preparation room, and all casters are locked. Marks are stored in the controller's memory, including the caster status (e.g., all locked) and the previous acceleration direction (e.g., z+).

[0095] From t0 to t1, the patient's examination bed remains still while the patient undergoes the initial examination.

[0096] At t1, the operator pushes the left front handle in curve 1004. From t1 to t2, the sensor detects increased edge forces in the x+ and z+ directions in curves 1002 and 1003, respectively, and increases the front horizontal handle force in the z+ direction in curve 1004.

[0097] At t2, in response to an indication of a force (e.g., multiple user interface forces) applied to the left front handle and the edge of the examination bed, all casters are simultaneously unlocked and the markings are removed. In some examples, unlocking all casters in response to more than one sensor detecting an increased force can enable one or more examination bed operators to move the examination bed without steering assistance. Additionally or alternatively, all casters can be unlocked to enable one or more examination bed operators to correct or redirect the patient examination bed's direction of travel.

[0098] From t2 to t3, the operator corrects the direction of travel of the patient examination bed. In curves 1002 and 1003, the edge forces of the examination bed in the x+ and z+ directions decrease, respectively, while the force of the left front handle in the z+ direction increases. The accelerometer detects the increased acceleration.

[0099] At t3, the bed edge force sensor did not detect any bed edge force. From t3 to t4, the force on the front horizontal handle and the acceleration in the z+ direction increased. At t4, in response to the operator turning the patient examination bed from the front handle in the z+ direction, the controller steers and locks the right rear caster. Steering and locking the right rear caster assists the controller in maintaining the direction of travel. Such assistance may be desirable when transporting patients through long corridors. From t4 to t5, the operator pushes the patient examination bed with the assistance of the steer-locked right rear caster.

[0100] In this way, increased control and maneuverability of the patient examination bed are achieved by controlling the rotation of its lockable casters. A pivot point can be provided at any of the multiple casters of the examination bed in response to sensor signals indicating a turn, thereby reducing operator turning effort and increasing flexibility in navigating various care settings. Increased tension and tilt variability can be reduced by sequentially unlocking or locking the casters in response to signals indicating a reverse procedure, resulting in more predictable bed movement and ease of operation. The technical advantage of the patient transfer system is that it can make medical imaging workflows more efficient, enabling higher-capacity utilization of the medical imaging system.

[0101] This disclosure also provides support for a method for controlling a patient examination bed with multiple lockable casters, the method comprising: sequentially adjusting the locking of the lockable casters in response to an instruction to reverse the patient examination bed. In a first example of the method, the reversal is based on acceleration. In a second example of the method, optionally including the first example, the reversal is based on a change in velocity. In a third example of the method, optionally including one or both of the first and second examples, the reversal is based on movement in the opposite direction to the most recent movement. In a fourth example of the method, optionally including one or more or each of the first to third examples, the reversal is based on a user interface force. In a fifth example of the method, optionally including one or more or each of the first to fourth examples, the reversal is also based on detecting a reverse handle force. In a sixth example of the method, optionally including one or more or each of the first to fifth examples, the reversal is based on detecting forward movement, then rest, then reverse movement. In a seventh example of the method, optionally including one or more or each of the first to sixth examples, the reversal is based on detecting forward movement, immediately followed by reverse movement. In an eighth example of the method, one or more or each of the first to seventh examples is optionally included, and the adjustment includes unlocking from a lock. In a ninth example of the method, one or more or each of the first to eighth examples is optionally included, and the adjustment includes fully unlocking from a fully locked state. In a tenth example of the method, one or more or each of the first to ninth examples is optionally included, and the adjustment includes reducing rolling friction of the lockable caster wheel. In an eleventh example of the method, one or more or each of the first to tenth examples is optionally included, and the adjustment further responds to undocking from a medical imaging device. In a twelfth example of the method, one or more or each of the first to eleventh examples is optionally included, and the method further includes: reducing force assistance for a first duration based on a reversal indication value less than a first threshold, and reducing force assistance for a second duration based on a reversal indication value greater than the first threshold. In a thirteenth example of the method, one or more or each of the first to twelfth examples is optionally included, and the method further includes: simultaneously unlocking the lockable caster in response to an indication of a multi-operator condition and a deceleration to stop less than a second threshold.

[0102] This disclosure also provides support for a method for controlling a patient examination bed with multiple lockable casters, the method comprising: sequentially unlocking the lockable casters during a first operation, and simultaneously unlocking the lockable casters during a second operation. In a first example of the method, the first operation includes an indication of reversing the patient examination bed, and the second operation includes an indication of one of multiple user interface forces and deceleration to a stop less than a second threshold. In a second example of the method, optionally including the first example, the method further comprises: reducing force assistance for a period of time during the first operation, and maintaining force assistance during the second operation.

[0103] This disclosure also provides support for a patient transfer system comprising: a medical imaging device; a patient examination bed selectively dockable to the medical imaging device; a plurality of lockable casters rotatably coupled to the patient examination bed; a sensor coupled to the patient examination bed; a controller communicatively coupled to the sensor and the lockable casters; and a memory storing executable instructions that, when executed, cause the controller to receive sensor signals from the sensor and sequentially adjust the locking of the lockable casters in response to an instruction to reverse the patient examination bed. In a first example of the system, the system further comprises a force-assist system communicatively coupled to the controller and the patient examination bed. In a second example of the system, optionally including the first example, the sensor is a force sensor.

[0104] As used herein, elements or steps listed in the singular and beginning with the word "a" or "an" should be understood to not exclude a plurality of said elements or steps unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the invention are not intended to be construed as excluding the existence of additional embodiments that also include the referenced features. Moreover, unless explicitly stated to the contrary, embodiments that "comprise," "include," or "have" elements or multiple elements having a particular characteristic may include additional such elements that do not have that characteristic. The terms "comprise" and "in..." are used as concise linguistic equivalents to the corresponding terms "comprising" and "wherein". Furthermore, the terms "first," "second," and "third," etc., are used merely as notations and are not intended to impose numerical requirements or a particular order of position on their objects.

[0105] This written description uses examples to disclose the invention, including the best mode, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any included methods. The scope of patentability of the invention is defined by the claims and may include other examples that would occur to those skilled in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that have minor differences from the literal language of the claims.

Claims

1. A method for controlling a patient examination bed having multiple lockable casters, the method comprising: The locking of the lockable casters is sequentially adjusted in response to an instruction to reverse the patient examination bed, wherein the reversal represents a dynamic switching event of opposite directions of movement. The force assistance is reduced for a first duration based on the magnitude of the inversion indication being less than a first threshold, and the force assistance is reduced for a second duration based on the magnitude of the inversion indication being greater than the first threshold, wherein the first duration is less than the second duration.

2. The method of claim 1, wherein the reversal is based on acceleration.

3. The method of claim 1, wherein the reversal is based on a change in velocity.

4. The method of claim 1, wherein the reversal is based on a motion in the opposite direction to the most recent motion.

5. The method of claim 1, wherein the inversion is based on user interface force.

6. The method of claim 5, wherein the reversal is further based on detecting a reverse handle force.

7. The method of claim 1, wherein the reversal is based on detecting forward motion, then a standstill, and then reverse motion.

8. The method of claim 1, wherein the reversal is based on the detection of a forward motion followed by a reverse motion.

9. The method of claim 1, wherein the adjustment includes unlocking from the lock.

10. The method of claim 1, wherein the adjustment includes fully unlocking from a fully locked position.

11. The method of claim 1, wherein the adjustment includes reducing the rolling friction of the wheel of the lockable caster.

12. The method of claim 1, wherein the adjustment further responds to undocking from the medical imaging device.

13. The method of claim 1, further comprising simultaneously unlocking the lockable caster in response to an instruction of either a multi-operator condition or a deceleration to a stop less than a second threshold.

14. A method for controlling a patient examination bed having multiple lockable casters, the method comprising: During the first operation, the lockable casters are unlocked sequentially, wherein the first operation includes an indication of reversing the patient examination bed, wherein the reversal represents a dynamic switching event of opposite directions of movement; During the second operation, the lockable caster is simultaneously unlocked, wherein the second operation includes one of a plurality of user interface forces and an indication of deceleration to a stop less than a second threshold; and During the first operation, the force assistance is reduced for a first duration based on the magnitude of the inversion indication being less than a first threshold, and the force assistance is reduced for a second duration based on the magnitude of the inversion indication being greater than the first threshold, wherein the first duration is less than the second duration, and the force assistance is maintained during the second operation.

15. A patient transfer system, the patient transfer system comprising: Medical imaging devices; A patient examination bed, which selectively docks with the medical imaging device; Multiple lockable casters are rotatably connected to the patient examination bed; Sensors, the sensors being connected to the patient examination bed; A controller, communicatively connected to the sensor and the lockable casters; A force-assist system, which is communicatively connected to the controller and the patient examination bed; and The memory stores executable instructions that, when executed, cause the controller to... Receive sensor signals from the sensor; The locking of the lockable casters is sequentially adjusted in response to an instruction to reverse the patient examination bed, wherein the reversal represents a dynamic switching event of opposite movement directions; and The force assistance is reduced for a first duration based on the magnitude of the inversion indication being less than a first threshold, and the force assistance is reduced for a second duration based on the magnitude of the inversion indication being greater than the first threshold, wherein the first duration is less than the second duration.

16. The patient transfer system of claim 15, wherein the sensor is a force sensor.

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