Patent Description:
The use of helicopters and other aircraft is well known and commonly utilized for rescuing and transporting injured or ill patients who may be located in an area which is difficult to access in the normal course, due to the absence of roads or adequate pathways leading to and from such area. Even where access is available, a helicopter rescue or transport may be needed where the patient needs to be transported to a hospital in less time than it would take for water or land operated forms of transportation, such as in ambulances.

Helicopter rescue of patients is typically accomplished by landing the helicopter nearby the person needing attention. However, there may be many instances where there is no suitable landing site or pad for the helicopter, and the patient must be reached and placed in the helicopter while the helicopter continues to remain airborne, hovering near the pickup site. In such instances, a typical manner for rescue is to lower a patient litter basket from the helicopter by means of a hoist, when the helicopter is more or less directly overhead or nearby the patient. The hoist may comprise a cable which is unreeled, the cable having a hook, swivel or other mechanical structure at its one end by means of which the patient litter basket is attached thereto. There may be a plurality of cables between the hook, swivel or other mechanical structure and the patient litter basket itself, in order to provide more stability to the patient litter basket.

One issue in such rescues relates to the possibility that the patient litter basket may begin to spin uncontrollably, which may be the result of ambient wind and weather conditions (such as fire driven windstorms), or the downdraft of the helicopter rotor itself. While a small amount of spin induced by such conditions may not be a problem, the induced spin may accelerate and increase so that the number of revolutions of the litter basket per minute becomes at least unpleasant for the patient, sometimes inducing sickness, and often dangerous to the patient or the rescue operation.

An example of a device for stabilizing a hoisted object is disclosed in <CIT>.

A patient litter basket spin control assembly is provided as defined by claim <NUM>.

A patient litter basket assembly is provided as defined by claim <NUM>.

A method for stabilizing a patient litter basket is provided as defined by claim <NUM>.

In various embodiments, the method further comprises simultaneously activating the first gyroscope and a second gyroscope to counter act the torque of the patient litter basket, wherein the gyroscopic counter torque comprises a sum of a first torque generated by the first gyroscope and a second torque generated by the second gyroscope.

The detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the inventions, it should be understood that other embodiments may be realized and that changes may be made without departing from the scope of the invention as defined by the claims. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented.

Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option.

With reference to <FIG>, a rescue basket assembly <NUM> (also referred to as a litter basket assembly) is illustrated, in accordance with various embodiments of the present disclosure. The assembly <NUM> includes a patient litter basket <NUM>, of elongate size and a somewhat narrower width, with a base <NUM> and sidewalls <NUM> defining a patient space <NUM>. The patient or person space <NUM> is of sufficient size to allow such person to be placed in the patient litter basket <NUM> in a supine position, and there may be appropriate contours, securing straps, mattresses or padding, and other structures to properly secure the person within the patient litter basket <NUM> in a secure and comfortable position.

The patient litter basket <NUM> may include a pair of connecting tabs <NUM> on each of the longitudinal side edges thereof. Other forms of connection besides connecting tabs may be provided on the patient litter basket <NUM> illustrated, in accordance with various embodiments of the present disclosure. A connector cable <NUM> may be secured in an aperture <NUM> of each of the connecting tabs <NUM>, and extends to a hook <NUM> with a swivel <NUM>. The hook <NUM> with swivel <NUM> is attached to a hoist line <NUM> at one end thereof. At the other end, the hoist line <NUM> is attached to a hoist drum or spool (not shown) which, in conventional fashion, can be rotated either by hand manually or, more conventionally in larger applications, by a hoist motor where the loads are heavier. The hoist spool is therefore able to raise and lower the hoist line <NUM> and the attached swivel <NUM> with hook <NUM> at the other end. It should be appreciated that each of the connector cables <NUM> may be attached to hoist line <NUM> via other known attachment devices other than swivel <NUM> and/or hook <NUM> (e.g., via a shackle, etc.) without departing from the scope of the invention as defined by the claims.

In various embodiments, assembly <NUM> includes one or more gyroscopes <NUM> to counteract spinning options of the patient litter basket <NUM>. It should be understood that gyroscopes <NUM> are schematically illustrated in <FIG> and that the positioning of gyroscopes <NUM> with respect to the patient litter basket <NUM> is not limited as such. In various embodiments, the gyroscopes <NUM> are mounted to sidewalls <NUM> to increase the distance between yaw axis <NUM> and gyroscopes <NUM>, thereby increasing the mass moment of inertia of the gyroscope assembly imparted to patient litter basket <NUM> about yaw axis <NUM>. In various embodiments, gyroscopes <NUM> are mounted to sidewalls <NUM>. In various embodiments, gyroscopes <NUM> are mounted to the outside of sidewalls <NUM>. In various embodiments, gyroscopes <NUM> are at least partially embedded within sidewalls <NUM>. In various embodiments, gyroscopes <NUM> are mounted to base <NUM>. In various embodiments, gyroscopes <NUM> are mounted to the bottom of patient litter basket <NUM> (e.g., to base <NUM>). Moreover, gyroscopes <NUM> may be least partially embedded within base <NUM>.

With reference to <FIG>, various schematic views of a patient litter basket assembly <NUM> including a patient litter basket <NUM> with a four gyroscope based configuration are illustrated, in accordance with various embodiments. In various embodiments, patient litter basket <NUM> may be similar to patient litter basket <NUM> of <FIG>.

Patient litter basket <NUM> may include a first pair of gyroscopes including a first gyroscope <NUM> and a second gyroscope <NUM> located at opposite sides of the patient litter basket <NUM>. For example, first gyroscope <NUM> may be located at first side <NUM> of patient litter basket <NUM> and second gyroscope <NUM> may be located at second side <NUM> of patient litter basket <NUM>. In various embodiments, first gyroscope <NUM> and second gyroscope <NUM> are located substantially midway between the ends (i.e., first end <NUM> and second end <NUM>) of patient litter basket <NUM>. For example, first gyroscope <NUM> and second gyroscope <NUM> may be located between <NUM>% and <NUM>% of the way between first end <NUM> and second end <NUM>. In various embodiments, first gyroscope <NUM> and second gyroscope <NUM> are located half way between first end <NUM> and second end <NUM>. First gyroscope <NUM> and second gyroscope <NUM> may be simultaneously activated to counteract a spinning motion of the patient litter basket <NUM>.

Patient litter basket <NUM> may include a second pair of gyroscopes including a third gyroscope <NUM> and a fourth gyroscope <NUM> located at opposite ends of the patient litter basket <NUM>. For example, third gyroscope <NUM> may be located at first end <NUM> of patient litter basket <NUM> and fourth gyroscope <NUM> may be located at second end <NUM> of patient litter basket <NUM>. In various embodiments, third gyroscope <NUM> and fourth gyroscope <NUM> are located substantially midway between the sides (i.e., first side <NUM> and second side <NUM>) of patient litter basket <NUM>. For example, third gyroscope <NUM> and fourth gyroscope <NUM> may be located between <NUM>% and <NUM>% of the way between first side <NUM> and second side <NUM>. In various embodiments, third gyroscope <NUM> and fourth gyroscope <NUM> are located half way between first side <NUM> and second side <NUM>. Third gyroscope <NUM> and fourth gyroscope <NUM> may be simultaneously activated to counteract a spinning motion of the patient litter basket <NUM>.

The gyroscope pairs are configured to counteract a spinning motion of the patient litter basket <NUM>. For example, if the patient litter basket <NUM> starts to spin about the yaw axis <NUM> in a first rotational direction, the gyroscope pairs (e.g., first gyroscope <NUM> and second gyroscope <NUM> and/or third gyroscope <NUM> and fourth gyroscope <NUM>) may be activated to provide a counter torque in a second rotational direction and prevent spinning. In various embodiments, the counter torque may be incrementally increased or decreased according to the spin rate of the patient litter basket <NUM>.

In various embodiments, the gyroscope pairs are configured to counteract a spinning motion of the patient litter basket <NUM> about the yaw axis <NUM>. The gyroscope pairs may be further configured to counteract a spinning motion of the patient litter basket <NUM> about the roll axis <NUM> and/or the pitch axis <NUM>. It will be appreciated that the torque imparted by each gyroscope will be based upon the orientation of the flywheel associated with the gyroscope. For example, each gyroscope may comprise a single flywheel that can be oriented in various directions, in accordance with various embodiments, or a plurality of flywheels each oriented in a fixed direction and dedicated to counteract rotation in a predetermined rotational direction, in accordance with various embodiments. In various embodiments, each gyroscope comprises a single flywheel oriented in a fixed direction.

In various embodiments, each gyroscope's construction includes a flywheel which is configured to spin and rotate about the axis of precession (e.g., the Z-axis). For example, in response to the flywheel being activated to spin about X-axis and torque is applied to rotate about axis of precession, the flywheel also exerts an equal and opposite torque to the gyroscope frame (which is connected to the patient litter basket <NUM>) due to conservation of angular momentum. Thus, if a single gyroscope is installed to counter act the spinning of patient litter basket <NUM> about the yaw axis <NUM>, the patient litter basket <NUM> may tend to experience rotation about X & Z axes, which may compromise the stability of the patient litter basket <NUM>. For this reason, patient litter basket assembly <NUM> may include two gyroscope pairs to provide the desired counter torque for a spinning basket, without compromising the stability of the basket and ensuring heightened safety.

The logic shown in the below table demonstrates the different axes of rotation of the gyroscopes. As seen, the net reaction torque on the patient litter basket <NUM> by the gyroscopes is zero. This ensures stability in the roll and pitch axes. Thus, all gyroscopes may work in tandem to produce net torque to counter the spin of the patient litter basket <NUM>. The control system may apply corrective forces, being consistent with the below logic to ensure stability at every instant of a rescue operation.

Providing four gyroscopes may ensure robust control of the patient litter basket <NUM> at all times. Moreover, more complex stability algorithms can be employed. Unexpected loading scenarios such as gust loading, vortex ring state effects while flying in ridges and valleys, and flying through down draught on a side of a mountain, which may each lead to instabilities, can be handled more effectively. A four gyroscope configuration may tend to be more suitable for high risk applications.

With reference to <FIG>, a schematic view of a gyroscope assisted control system <NUM> for controlling the gyroscopes and performing stabilization functions for a patient litter basket during rescue operations, is illustrated, in accordance with various embodiments. In various embodiments, the control system <NUM> comprises a main control system <NUM> and a plurality of gyroscopes (e.g., first gyroscope <NUM>, second gyroscope <NUM>, third gyroscope <NUM>, fourth gyroscope <NUM>). Although illustrated as including four gyroscopes, the number of gyroscopes of a control system <NUM> is not limited in this regard. For example, control system <NUM> may comprise only two gyroscopes, or may comprise other quantities of gyroscopes. Moreover, although illustrated as comprising a main control system <NUM>, it is contemplated herein that each gyroscope may have its own dedicated control system. For example, each gyroscope may include its own controller, memory, power source, motion sensor, and any combination thereof.

In various embodiments, the main control system <NUM> includes a controller <NUM> and a memory <NUM> (e.g., a database or any appropriate data structure; hereafter "memory <NUM>" also may be referred to as "database <NUM>"). The controller <NUM> may include one or more logic devices such as one or more of a central processing unit (CPU), an accelerated processing unit (APU), a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or the like (e.g., controller <NUM> may utilize one or more processors of any appropriate type/configuration, may utilize any appropriate processing architecture, or both). In various embodiments, the controller <NUM> may further include any non-transitory memory known in the art. The memory <NUM> may store instructions usable by the logic device to perform operations. Any appropriate computer-readable type/configuration may be utilized as the memory <NUM>, any appropriate data storage architecture may be utilized by the memory <NUM>, or both. In various embodiments, controller <NUM> may comprise a PID controller for stabilizing the litter basket.

The database <NUM> may be integral to the control system <NUM> or may be located remote from the control system <NUM>. The controller <NUM> may communicate with the database <NUM> via any wired or wireless protocol. In that regard, the controller <NUM> may access data stored in the database <NUM>. In various embodiments, the controller <NUM> may be integrated into computer systems onboard an aircraft. Furthermore, any number of conventional techniques for electronics configuration, signal processing and/or control, data processing and the like may be employed. Also, the processes, functions, and instructions may include software routines in conjunction with processors, etc..

System program instructions and/or controller instructions may be loaded onto a non-transitory, tangible computer-readable medium having instructions stored thereon that, in response to execution by the processor, cause the controller <NUM> to perform various operations. The term "non-transitory" is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se.

The instructions stored on the memory <NUM> of the controller <NUM> may be configured to perform various operations, such as performing patient litter basket stabilization by operating one or more of gyroscopes <NUM>, <NUM>, <NUM>, <NUM>.

In various embodiments, the main control system <NUM> from <FIG> further comprises a motion sensor <NUM>. Motion sensor <NUM> may be mounted to a patient litter basket (e.g., patient litter basket <NUM> of <FIG>) to detect an orientation of the patient litter basket. Motion sensor <NUM> may be an accelerometer, or any other suitable motion sensor suitable for detecting an orientation and/or acceleration of patient litter basket <NUM>.

In various embodiments, the main control system <NUM> from <FIG> further comprises a power source <NUM>. The power source <NUM> may comprise any power source known in the art, such as a battery, a solar source, an alternating current (AC) source, a direct current (DC) source, a rechargeable source, or the like. In various embodiments, a single power source <NUM> is provided for all gyroscopes. In various embodiments, each gyroscope <NUM>, <NUM>, <NUM>, <NUM> includes a dedicated power source <NUM>. In various embodiments, each gyroscope pair (e.g., gyroscopes <NUM>, <NUM> and gyroscopes <NUM>, <NUM>) includes a dedicated power source <NUM>.

In various embodiments, the main control system <NUM> is in operable communication with each gyroscope in the plurality of gyroscopes (e.g., gyroscopes <NUM>, <NUM>, <NUM>, <NUM>). With momentary reference to FIG. 3A, during operation of control system <NUM>, motion sensor <NUM> may detect an angular acceleration of patient litter basket <NUM> about yaw axis <NUM>. In response to motion sensor <NUM> detecting an angular acceleration beyond a predetermined threshold angular acceleration, controller <NUM> may activate the gyroscopes (e.g., gyroscopes <NUM>, <NUM>, <NUM>, <NUM>) to counter act the torque of patient litter basket <NUM> by applying appropriate gyroscopic torque. For example, if patient litter basket <NUM> is rotating about yaw axis <NUM> in a first rotational direction, controller <NUM> may activate the gyroscopes (e.g., gyroscopes <NUM>, <NUM>, <NUM>, <NUM>) to counter act the torque of patient litter basket <NUM> by applying gyroscopic torque in a second rotational direction opposite the first rotational direction to slow the rotation of the patient litter basket <NUM> in the first rotational direction. In various embodiments, the controller <NUM> may modulate the counter torque of the gyroscopes so that the counter torque counters the rotational movement of the patient litter basket <NUM> to stabilize the patient litter basket <NUM> by preventing the spin.

In various embodiments, each gyroscope <NUM>, <NUM>, <NUM>, <NUM> includes a flywheel <NUM>, <NUM>, <NUM>, <NUM>, respectively, which can be activated by rotating the flywheel about an axis to apply gyroscopic torque in a desired direction. Main control system <NUM> may activate the gyroscopes and stabilize the patient litter basket <NUM> upon reaching the threshold angular acceleration, for example as per the logic referred in table <NUM>. In various embodiments, each gyroscope is capable of producing torque in the range of <NUM> to <NUM> N-m. In various embodiments, each gyroscope is capable of producing torque sufficient to slow an angular acceleration of the patient litter basket <NUM> and the particular torque value may vary based on the positioning of the gyroscope with respect to the rotational axis and the overall mass of the patient litter basket <NUM>.

With reference to <FIG>, various schematic views of a patient litter basket assembly <NUM> including a patient litter basket <NUM> with a two gyroscope based configuration are illustrated, in accordance with various embodiments. In various embodiments, patient litter basket assembly <NUM> may be similar to patient litter basket assembly <NUM> of <FIG>. With respect to <FIG>, elements with like element numbering, as depicted in FIG. <FIG>, are intended to be the same and will not necessarily be repeated for the sake of clarity. The control system of patient litter basket assembly <NUM> may apply corrective forces, being consistent with the below logic to ensure stability at every instant of a rescue operation.

The objective of stabilizing the patient litter basket <NUM> may also be achieved with the use of two gyroscopes. The stability logic explained for the four gyroscope configuration is consistent for the two gyroscope configuration as well. A two gyroscope layout may ensure stabilization solution tailored for a rotor downwash scenario. Having two gyroscopes may help to reduce the overall weight of the system with respect to a four gyroscope configuration. A two gyroscope configuration may tend to be more suitable for mid to low risk applications.

With reference to <FIG>, an example gyroscope <NUM> is illustrated, in accordance with various embodiments. Gyroscopes <NUM> of <FIG>, and/or gyroscopes <NUM>, <NUM>, <NUM>, <NUM> of <FIG> may be similar to gyroscope <NUM>. Gyroscope <NUM> includes a flywheel <NUM> rotatable about a flywheel rotation axis <NUM>. In operation, flywheel <NUM> is powered (e.g., by a motor) to rotate about flywheel rotation axis <NUM> to impart a torque that is generally orthogonal to the flywheel rotation axis <NUM> and proportional to the inertia and the rotational speed of the spinning mass (i.e., flywheel <NUM>). Flywheel <NUM> may be mounted rotatably mounted to a frame <NUM>. In various embodiments, flywheel <NUM> is rotatably mounted to frame <NUM> via a first gimbal <NUM>, whereby an orientation of flywheel <NUM> is variable to change the direction of torque output by gyroscope <NUM>. In various embodiments, flywheel <NUM> is rotatably mounted to frame <NUM> via a second gimbal <NUM>, whereby an orientation of flywheel <NUM> is further variable to change the direction of torque output by gyroscope <NUM>. In various embodiments, flywheel <NUM> is rotatably mounted to second gimbal <NUM>, which is rotatably mounted to first gimbal <NUM>, which is in turn rotatably mounted to frame <NUM>. In this manner, flywheel <NUM> may be rotatable in three dimensions. However, it is contemplated herein that a gyroscope of the present disclosure may have a flywheel rotatable about a fixed axis, in accordance with various embodiments. Furthermore, a gyroscope of the present disclosure may have a flywheel rotatable in only two dimensions. The variability of the flywheel may be based upon the axis about which stabilization is desired. For example, if stabilization is desired only about the yaw axis, a gyroscope having a flywheel configured to rotate about a single axis may be sufficient. However, if stabilization is desired about roll and pitch axes, a gyroscope having a flywheel configured to rotate about a three different axes may be provided. Moreover, multiple gyroscopes having a flywheel configured to rotate about a single axis, but each oriented in a different direction, may be provided to give multi-axis stabilization, in accordance with various embodiments.

In the detailed description herein, references to "one embodiment", "an embodiment", "various embodiments", etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments within the scope of the claims.

Claim 1:
A patient litter basket spin control assembly comprising:
a first gyroscope (<NUM>, <NUM>), comprising a first flywheel (<NUM>), disposed, in use, at a first end of a patient litter basket (<NUM>);
a second gyroscope (<NUM>), comprising a second flywheel, disposed, in use, at a second end of a patient litter basket;
a motion sensor (<NUM>) ;
a controller (<NUM>) associated with the first gyroscope and configured to activate the first gyroscope by rotating the first flywheel about a first flywheel rotation axis and to activate the second gyroscope by rotating the second flywheel about a second flywheel rotation axis to generate a gyroscopic torque as a counter torque in a rotational direction to slow the angular acceleration of the patient litter basket, in use, in response to the motion sensor detecting an angular acceleration of the patient litter basket beyond a predetermined threshold angular accelerator; and
a power source (<NUM>) associated with the first gyroscope.