Patient support apparatus with powered unloading dynamic weigh adjustment

Patent metadata

Field	Value
Publication number	US-11730652-B2
Application number	US-202017131934-A
Country	US
Kind code	B2
Filing date	Dec 23, 2020
Priority date	Dec 30, 2019
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A system for loading a patient transport apparatus into a vehicle is described. The system includes a loading and unloading system including a track and a trolley supporting a receiver movable between locked and unlocked configurations. The system also includes a patient transport apparatus for attachment to the loading and unloading system including a base, a litter, and a lift mechanism to facilitate arranging the litter at different heights relative to the base with an actuator movable between fully-retracted and fully-extended configurations, a coupler for engaging the receiver to secure the patient transport apparatus, first and second sensors configured to output a first signal and second signal and a controller to determine a target lift configuration during unloading from the emergency based on first and second values and to drive the actuator to the target lift configuration to limit relative movement between the patient transport apparatus and the trolley.

First claim

What is claimed is:

1. A system for use in removably loading a patient transport apparatus into an emergency vehicle, said system comprising:
a loading and unloading system for attaching to the emergency vehicle, said loading and unloading system including:
a track for mounting to the emergency vehicle, and
a trolley slidably mounted to said tracks, said trolley supporting a receiver movable between a locked configuration and an unlocked configuration; and

a patient transport apparatus configured for releasable attachment to said loading and unloading system, said patient transport apparatus including:
a base supporting a wheel for engagement with a ground surface,
a litter defining a patient support surface to support a patient,
a lift mechanism to facilitate arranging said litter at different heights relative to said base with an actuator movable between a plurality of lift configurations including a fully-retracted configuration and a fully-extended configuration,
a coupler operatively attached to said litter for releasably engaging said receiver of said trolley to secure said patient transport apparatus to said trolley when said receiver operates in said locked configuration,
a first sensor configured to output a first signal indicative of a height of said litter relative to said base,
a second sensor configured to output a second signal indicative of applied force occurring between said base and said litter, and
a controller in communication with said actuator of said lift mechanism, said first sensor, and said second sensor, said controller being configured to determine a target lift configuration during unloading from the emergency vehicle as said actuator moves toward said fully-extended configuration, said target lift configuration being defined to inhibit compressing said patient transport apparatus between said wheel engaging the ground surface and said coupler engaging said receiver based on:
a first value associated with at least one of said first signal and said second signal determined in response to contact of said wheel occurring with the ground surface; and
a second value associated with at least one of said first signal and said second signal determined in response to said patient transport apparatus at least partially moving out of support from at least a portion of said trolley; and

said controller being further configured to drive said actuator to said target lift configuration defined based on said first value and said second value to facilitate unloading said patient transport apparatus supported on the ground surface in an uncompressed state to limit relative movement between said patient transport apparatus and said trolley as said receiver moves from said locked configuration to said unlocked configuration to release said coupler.

2. The system of claim 1 , wherein said trolley includes an arm moveable between: an engaged configuration in which said arm is supporting said patient transport apparatus, and a released configuration in which said arm in not supporting said patient transport apparatus.

3. The system of claim 2 , wherein the trolley includes an arm sensor configured to output an arm signal indicative of whether said arm is in said engaged configuration or said released configuration.

4. The system of claim 3 , wherein said controller determines said target lift configuration in response to output of said arm signal indicating that said arm has moved from said engaged configuration to said released configuration.

5. The system of claim 1 , wherein said actuator defines a cylinder supporting a piston coupled to a rod arranged for movement along the cylinder, said lift mechanism further comprising a fluid reservoir and a pump driven by a motor to direct hydraulic fluid from the fluid reservoir to the cylinder, said controller being configured to control a flow of hydraulic fluid between said cylinder and said fluid reservoir.

6. The system of claim 5 , wherein said second sensor is a pressure sensor and said second signal output from said second sensor is indicative of a magnitude of pressure of said hydraulic fluid.

7. The system of claim 6 , wherein the second signal output from said second sensor is indicative of the magnitude of pressure of said hydraulic fluid at a first end of the cylinder, said system further comprising a pressure sensor configured to output a pressure signal indicative of a magnitude of pressure of said hydraulic fluid at a second end of said cylinder.

8. The system of claim 1 further comprising a strain gauge configured to output a strain signal indicative of engagement of said wheel with the ground surface.

9. The system of claim 1 , wherein said coupler comprises at least one pin and said receiver comprises at least one latch, said at least one pin configured to engage with said at least one latch.

10. The system of claim 1 , further comprising a user interface with an input control arranged for user engagement to move the receiver between the locked configuration and the unlocked configuration.

11. A patient transport apparatus for use with a loading and unloading system of an emergency vehicle, the loading and unloading system having a trolley with a receiver movable between a locked configuration and an unlocked configuration, said patient transport apparatus comprising:
a base supporting a wheel for engagement with a ground surface;
a litter defining a patient support surface to support a patient;
a lift mechanism to facilitate arranging said litter at different heights relative to said base with an actuator movable between a plurality of lift configurations including a fully-retracted configuration and a fully-extended configuration;
a coupler operatively attached to said litter for releasably engaging the receiver of the trolley to secure said patient transport apparatus to the trolley when the receiver operates in the locked configuration;
a first sensor configured to output a first signal indicative of a height of said litter relative to said base;
a second sensor configured to output a second signal indicative of applied force occurring between said base and said litter; and
a controller in communication with said actuator of said lift mechanism, said first sensor, and said second sensor, said controller being configured to determine a target lift configuration during unloading from the emergency vehicle as said actuator moves toward said fully-extended configuration, said target lift configuration being defined to inhibit compressing said patient transport apparatus between said wheel engaging the ground surface and said coupler engaging said receiver based on:
a first value associated with at least one of said first signal and said second signal determined in response to contact of said wheel occurring with the ground surface; and
a second value associated with at least one of said first signal and said second signal determined in response to said patient transport apparatus at least partially moving out of support from at least a portion of the trolley; and

said controller being further configured to drive said actuator to said target lift configuration defined based on said first value and said second value to facilitate unloading said patient transport apparatus supported on the ground surface in an uncompressed state to limit relative movement between said patient transport apparatus and the trolley as the receiver moves from the locked configuration to the unlocked configuration to release said coupler.

12. The patient transport apparatus of claim 11 , wherein the first value is determined at a first time and the second value is determined at a second time, said second time occ

Assignees

• Stryker Corp

Inventors

• Mansfield Joshua Alan

Classifications

• A61G7/1036 Primary

  facilitating loading and unloading of the patient, e.g. using flaps or additional tilting · CPC title

• A61G7/1046

  Mobile bases, e.g. having wheels · CPC title

• A61G7/1049

  Attachment, suspending or supporting means for patients · CPC title

• A61G3/0218

  Loading or unloading stretchers (transfer using ramps, lifts or the like A61G3/06 - A61G3/066; accommodating or securing wheelchairs or stretchers A61G3/08 - A61G3/0891) · CPC title

• A61G3/062

  using lifts connected to the vehicle · CPC title