Anti-collision safety system on a patient support apparatus

Abstract

The invention relates to patient support apparatuses used in healthcare and nursery facilities, such as medical or nursing beds, stretchers, birthing beds, child's beds etc., (hereinafter generally referred to as patient support apparatuses or beds) and detection of obstacles on these patient support apparatuses, most commonly obstacles located on the undercarriage or between the individual parts of these patient support apparatuses. The presented solution discloses a new anti-collision safety system capable of quick detecting and evaluating an obstacle within any part of the patient support apparatus or during positioning of the support deck thereof. This anti- collision safety system evaluates and directly influences further movement of the frame of the patient support apparatus relative to another part of the patient support apparatus or stops the positioning of patient support deck or returns already positioned part of the patient support apparatus to its original state. The system also addresses a risk of collision with an obstacle on the bed itself, or a collision with an obstacle on the floor or in the vicinity of the patient support apparatus when transporting such apparatus from the point A to the point B. Alternatively, the disclosed anti-collision safety system can be used to locate a patient on the patient support apparatus or to detect patient exiting the bed, i.e. detection of so called bed exit.

Description

[0001] Anti-collision Safety System on a Patient Support Apparatus

[0002] Technical Field

[0003] The invention relates to patient support apparatuses used in healthcare and nursery facilities, such as medical or nursing beds, stretchers, birthing beds, child's beds etc., (hereinafter generally referred to as patient support apparatuses or beds) and detection of obstacles on these patient support apparatuses, most commonly obstacles located on the undercarriage or between the individual parts of these patient support apparatuses. The presented solution discloses a new anti-collision safety system capable of quick detecting and evaluating an obstacle within any part of the patient support apparatus or during positioning of the support deck thereof. This anti¬ collision safety system evaluates and directly influences further movement of the frame of the patient support apparatus relative to another part of the patient support apparatus or stops positioning of the patient support deck or returns already positioned part of the patient support apparatus to its original state. The system also addresses a risk of collision with an obstacle on the bed itself, or a collision with an obstacle on the floor or in the vicinity of the patient support apparatus when transporting such apparatus from the point A to the point B. Alternatively, the disclosed anti-collision safety system can be used to locate a patient on the patient support apparatus or to detect patient exiting the bed, i.e. detection of so called bed exit.

[0004] Prior Art

[0005] In the current state of the art, patient support apparatuses equipped with casters are commonly used in healthcare and nursing facilities. These casters allow such patient support apparatuses to be moved from one location to another, for example, from a doctor's office or operating room to a nursing room or intensive care unit. Such patient support apparatuses include, for example, hospital beds, nursing beds and chairs, or emergency stretchers, paediatric beds, or birthing beds, hereinafter generally referred to as patient support apparatuses or hospital beds or simply beds.

[0006] Most patient support apparatuses comprise an undercarriage, an undercarriage frame to which a lower part of the lifting mechanism is attached, and a frame of support deck to which an upper part of the lifting mechanism is attached. The support deck isattached to the frame of the support deck and is typically divided into several pivotably connected parts or sections, with a mattress placed on it. A headboard on one side and a footboard on the other side is attached to the support deck frame, as well as side rails located longitudinally on the support deck. The lifting mechanism of the patient support apparatus, as well as, for example, an auxiliary fifth wheel on the undercarriage are driven or controlled by electric or hydraulic motors connected to a control unit of the subjected patient support apparatus.

[0007] The upper frame of the patient support apparatus supports the support deck which is divided into several pivotably connected parts allowing articulation or height adjustment or repositioning of the support deck to various positions suitable for comfortable lying or sitting in bed, or for application of medical therapy. Such segmented support deck typically consists of 2, 3, 4, or more pivotably connected parts. The support deck thus comprises a back part, a sitting part, a leg part and a foot section in mutual articulating connection to position a patient into positions corresponding to patient's medical needs or simply to allow for comfortable lying in bed. On the underside, the individual parts of the support deck comprise positioning mechanisms in the form of hydraulic or electric actuators or motors, or other suitable types of motors, which adjust the position of the respective part of the support deck.

[0008] The current state of the art discloses patient support apparatuses with many types of control and positioning devices that move individual parts of the bed or individual sections of the support deck, such as electric motors or hydraulic motors, or various lifting mechanisms that move the entire patient support apparatus upward and downward, such as electronic or hydraulic columns, or alternatively other lifting mechanisms such as scissor lift systems. All these electronic positioning mechanisms are controlled by a control unit of the patient support apparatus further comprising a controller, which is located either as a hanging or a remoted controller, or is integrated as a control panel having display with control buttons on any side rail of the patient support apparatus. All electronically controlled positioning parts of the patient support apparatus are at risk of sudden collision, either with an obstacle located beneath such patient support apparatus or between individual parts thereof, alternatively, moving positioning parts of the patient support apparatus may pinched any limb part of nursing staff, patient, or other people in the vicinity of the support deck.In the current state of the art, systems for detecting collisions of obstacles with the support deck or with the undercarriage, or in the area under the bed are commonly known. These systems are usually parts of hospital, transport or nursing beds, and serve mainly to prevent unwanted harm to patients and medical staff, when the support deck moves downwards in relation to the undercarriage. In such situation, an undesired collision with an obstacle located on the undercarriage or in the area under the support deck may occur, caused by downward movement of the support deck. Obstacles on the undercarriage may be objects such as water buckets or other instruments, infusions, oxygen bottles or IV poles, or limbs of a patient or medical staff, or other persons moving around the patient support apparatus. The movement of the support deck downward in relation to the undercarriage occurs, for example, when medical staff operates the controllers or due to the unintentional activation of one of the foot controls on the undercarriage by a person near the bed, or even by the patient himself, if the controller drops down. Collision may also occur with an unknown device that is placed unexpectedly around the patient support apparatus if the patient chooses to change the position of the support deck. In such a case, a collision with a possible obstacle may occur, as the patient is not aware of any obstacle and cannot check that the patient support apparatus moves in the correct way. For any such situation it is desired to have the patient support apparatus equipped with a safety device that can detect the risk of collision. It is just the situation when personal injury may occur if movement of the support deck downward in relation to the undercarriage is inadvertently triggered. More common accidents with serious consequences are represented by pinching or squeezing a part of a limb located within the area of movement between the support deck and the lower frame of the patient support apparatus, or during cleaning and disinfection thereof. Therefore, it is necessary to provide the patient support apparatus with safety features, or to install a safety device on the patient support apparatus that stops the movement of support deck or a part of the support deck in case of collision with an obstacle or at least provides additional alert of collision.

[0009] The prior art discloses a solution in the patent US 7834768 (HILL ROM Inc., " Obstruction Detection Apparatus for a Bed”), in which safety of a patient support apparatus is enhanced using sensors that measure the distance between the frame ofthe support deck and the undercarriage frame. If an obstruction occurs on the undercarriage of the patient support apparatus, the system of sensors sense that the distance between the undercarriage and the support deck of the patient support apparatus is not the same at all points resulting in obstruction detection. Consequently, the patient support apparatus is stopped. Due to the large number of sensors, the system is prone to malfunctions. The sensors themselves may malfunction if the patient support apparatus is placed, for example, near a light source, which negatively affects proper functioning of sensors and can cause false alarms that interfere with normal operations of the patient support apparatus. The large number of sensors also results in high costs for production and maintenance.

[0010] Another solution known is the prior art is patent US 7472437 (HILL ROM Inc., " Hospital Bed Obstacle Detection Device and Method"), which discloses a similar device and method for enhancing bed safety in the event of a collision between the support deck and an obstacle. The system uses an array of optical sensors attached to the undercarriage of the patient support apparatus. The array of optical sensors is positioned on the opposite sides of the undercarriage of the bed, with one side acting as a transmitter and the other as a receiver. If the optic path between the sensors is physically interrupted, the control unit stops movement of the surface deck. Due to placement of the sensors along the entire undercarriage, this system is too large and increases the minimum height to which the patient support apparatus can be lowered, which reduces competitiveness as well as safety of the bed in terms of a risk of fall of a patient. Due to placement of the array of optical sensors, ambient light reflecting off the polarizing mirrors causes false alarms, which then stop movement of the support deck even in situations where it is not expected or desired. It is also a highly failure- prone system with high manufacturing and service costs.

[0011] The same patent family as the patent mentioned above includes also patent EP1496830 (HILL ROM Inc., " Hospital Bed Obstacle Detection Device”). This document discloses an obstacle detection system comprising a device for generating a wireless barrier in the path of lifting of the frame of the patient support apparatus. Detection components detect the transmitted wireless barrier and any interruption thereof. The device comprises an optical barrier generator and a detection component for detecting the optical barrier connected to a control unit, wherein the control unit is configured to prevent movement of the support deck and lifting of the frame in case ofa failure of the optical barrier detector. The detection system is due to its design, which consists of precision optically tuned mirrors, susceptible to vibrations that cause the optical barrier to deviate outside the receiving section, and the optical barrier itself is susceptible to deformation due to surrounding equipment, which can cause system inaccuracy and may be a source of false alarms that stop movement of the support deck.

[0012] Similarly, US patent no. 8502663 (HILL ROM Inc., “Hospital Bed Obstacle Detection Apparatus") discloses a sensor device attached to the frame of a patient support apparatus, consisting of two conductive surfaces, wherein an air gap and insulating material are partly between these conductive surfaces, ensuring that the sensor is disconnected when not activated, if an obstacle presses against the upper part of the sensor, the upper layer of the sensor is compressed toward the lower layer. This compression then causes the upper conductive layer to connect with the lower conductive layer, creating a conductive contact that is subsequently interpreted as a closure, and the control system stops positioning of the patient support apparatus.

[0013] The aforementioned examples clearly show that most systems designed to prevent collisions between the frame of a patient support apparatus or its components and obstacles in the path of movement are often quite costly or complex in terms of materials, which in turn leads to many other disadvantages, whether in the form of malfunctions, complicated installation, or unclear definition of the monitored area where a collision with an obstacle could occur. Most of these systems must be integrated into the patient support apparatus already from the very beginning, i.e. from the start of production, and it is very difficult to install such devices on the patient support apparatus later. In addition, not all of the systems mentioned are suitable for monitoring obstacles in the vicinity of a patient support apparatus. Some systems cannot be used to detect collision of the patient support apparatus with a potential obstacle being on the side and thus stop the patient support apparatus when being transported. Another disadvantage of the aforementioned systems is that they cannot be easily installed into existing electrically positioned or driven patient support apparatuses that do not have any safety devices at all.

[0014] The purpose of the presented and disclosed solution is to introduce a new device that enhances safety of hospital, transport, and nursing beds by preventinginjury to patients or medical staff resulting from movement of a part of the support deck toward the frame of the support deck or downward movement of the support deck in relation to undercarriage, and detects potential collisions with obstacles. The presented solution aims to eliminate all the aforementioned shortcomings and disadvantages of known prior art solutions and to maximize safety in the largest possible area where a collision with an obstacle may occur. The presented system also enables detecting an obstacle when the patient support apparatus moves any direction forward, backward, or sideways. The system can evaluate and monitor sensor damage to determine as quickly as possible whether the system requires repair or if sensor components or other parts of the system need to be replaced. The disclosed system can be very easily supplied and installed on existing patient support apparatuses that do not enjoy any safety system of this type. It can be also added as a standalone device to existing patient support apparatuses that lack any of the aforementioned safety features, or the system can be installed as an accessory feature to low-cost patient support apparatuses.

[0015] Summary of the Invention

[0016] The aforesaid challenges and disadvantages are overcome by below described anti-collision safety system designed to prevent collisions with obstacles or injuries to patients, staff, or other individuals. This system can be integrated into patient support apparatuses or easily added to any existing patient support apparatuses to improve safety of such patient support apparatuses, such as hospital beds or stretchers for emergency medical services, nursing beds with an undercarriage, or birthing beds and paediatric beds, hereinafter collectively referred to as patient support apparatuses or simply beds. These patient support apparatuses generally comprise an undercarriage with four casters, can have various powered wheels or additional driven wheels (a so- called fifth driven wheel), or may have central dual control of all four casters.

[0017] The anti-collision safety system disclosed herein is designed to detect obstacles on the undercarriage of a patient support apparatus, as well as to detect collisions between the movable frames of the support deck or between the frame of the support deck and the undercarriage. The system also detects potential collisions with obstacles when transporting the patient support apparatus with a patient from one room to another. Alternatively, the system can be used to detect presence of a patient on thepatient support apparatus, thereby preventing a risk of injury or the patient leaving the bed despite the patient is supposed to stay in. The system is also capable of identifying own external and internal faults and subsequently alerting an operator of need for service. The system is also capable of signalling a need to replace a component of the anti-collision safety system. The control unit can be remotely connected directly to the service centre and can thus inform a service technician of any need to repair a component of the system or the entire system.

[0018] The purpose of the disclosed solution is to introduce, in contrast to previously known and used solutions, a new system or device that enhances safety of patient support apparatuses with regard to patient health or injuries to medical staff resulting from movement of the patient support apparatus or the support deck relative to the undercarriage, or resulting from movement of another part of the support deck.

[0019] The disclosed anti-collision safety system consists of at least one detection belt connected by a connector to the other detection belt that is attached via an outlet connector to a control unit, preferably via an expander. The detection belt can be attached to the control unit directly or via a set of peripheral devices. The detection belt or belts can be located on various parts of the patient support apparatus where a potential risk of collision may occur, such as on the undercarriage and / or the bottom side of the support deck, or a frame of the support deck. The detection belts can also be attached to the side rail edge or, if necessary, to the headboards, either from the side or bottom part. The detection belts comprise an adhesive layer on one side, enabling easy installation of this anti-collision safety system on any type of patient support apparatuses where patients or staff safety needs to be ensured. On the other side, the detection belt comprises a washable, durable layer made of plastic, rubber, or silicone, ensuring the belt durability and safety. The detection belt can also be inserted into the embossment or creases of the frame of the patient support apparatus or into rails that are part of the frame of the patient support apparatus, or such rails bearing the detection belts can be mounted to the patient support apparatus additionally.

[0020] Preferably, the anti-collision safety system disclosed herein may comprise one or more detection belts located, for example, on the undercarriage of a patient support apparatus or on the bottom side of the support deck or on any other part of the patientsupport apparatus. The detection belt consists of a silicone film or housing that forms an outer protective layer. The protective layer is made of a non-conductive material, wherein inside there are two strips made of conductive material, such as copper, which are interleaved with at least one layer of a plastic, partially conductive material. Such designed detection belt acts as a force-sensitive resistor (a variable resistor), wherein, depending on the force applied to the outer side of the detection belt, the plastic material located between the conductive strips is compressed from its initial state into a state of partial deformation. This partial deformation causes moving of the conductive strips of the detection belt closer together, thereby increasing the flow of electric current between the upper and bottom conductive strips through the plastic layer. Electric current flows through the conductive strips of the detection belt constantly for the entire period when the detection belt is connected to a power connection. Increase in electric current flow results in a change in electrical resistance in the detection (sensory) belt, specifically, the initial electrical resistance decreases but never reaches zero. This decrease can be interpreted as an obstacle with a certain mass or pressure exerted on the surface of the detection belt from the sensing side of this belt.

[0021] Another advantage is that, thanks to the linear increase and decrease in the electrical resistance of the detection belt, it is possible to determine, using evaluation or assessment unit of a control unit, at what measured resistance value the movement of a part of the patient support apparatus (the support deck, the frame of the support deck, or the entire patient support apparatus) will be reversed back to original position or stopped or at what measured resistance value an obstacle is detected and consequently movement of the subjected part of the patient support apparatus is stopped.

[0022] Another advantage of this solution is the ability to quickly and easily detect a critical failure of the detection belt in case when the layer of partially conductive plastic material is damaged. A tear or other damage to this layer results in an unintended connection between two conductive strips, causing a short circuit, which indicates destructive damage to the detection belt that needs to be replaced consequently.

[0023] Another advantage is the size of the detection belt (or sensory belt) itself wherein due to its height (belt thickness) of just a few millimetres, the detection belt can be installed even in space-constrained areas, allowing the patient supportapparatus to be lowered to its lowest position while maintaining safety operation. Another advantage of the detection belt is its length and width, as the belts can be of any length and width depending on how large area needs to be covered. The detection belt can be as long and wide as the area where the monitored risk could potentially occur.

[0024] Use of the detection belt provides a new and enhanced level of protection, as its dimensions allow it to be installed even in confined spaces, such as the gaps between the side rails and the surface deck or the frame of the patient support apparatus where a patient’s or caregiver’s fingers could easily get pinched. Small objects, such as pencils, can often get stuck in these areas, which can lead to subsequent damage to the entire patient support apparatus. Another significant advantage is the ability to easily detect partial or complete damage to the detection belt, as well as reliable detection of an obstacle on the undercarriage, beneath the support deck of the patient support apparatus, or between the support deck and the frame thereof, thereby consequently to stop movement of the patient support apparatus or any part of it.

[0025] Lastly, another advantage of this anti-collision safety system is that it can be easily installed in the required location on any patient support apparatus, and the control unit can be configured as a device for detection of obstacles between the individual parts of the patient support apparatus, or for detection of obstacles or collisions with obstacles when the patient support apparatus is moved from one location to another. Upon impact with an obstacle, the detection belt senses the impact, and the control unit either stops further movement of the patient support apparatus in the given direction or sends alert to staff to stop the patient support apparatus or any part of it. The alert can be in the form of an audible signal or a voice instruction that clearly informs a user, an operator, or a patient of a current situation and following consequent actions.

[0026] Detection belts can also be used as a device for detection of a patient being in bed or as a detector of attempts to leave the bed by patient (so-called "bed exit”). In such case, the detection belts can be located on the side rails of the patient support apparatus or alongside of the side rails or on the support deck under the mattress or on the edge of the frame of the support deck or the mattress. Using these belts enableseasy detection of change of the patient’s position on the support deck, as the control unit is capable to evaluate in which part of the support deck interruption, increase, or decrease in voltage on the given detection belt occurs. Control unit consequently sends an audible alert in the form of an audio signal or voice instruction, which clearly informs a user, an operator, or a patient what to do. In case of voice alert, staff or any caregiver can specify which voice instruction the control unit should issue. Such voice instruction can be selected from a list of instructions predefined in the control unit or can be recorded into the control unit externally.

[0027] The disclosed technical solution for the anti-collision safety system comprising detection belts can be an integrated part of the patient support apparatus, which means that the detection belts are installed (adhered, heat-sealed, or attached by another suitable method) in the appropriate locations according to need for safety or detection function (detecting the patient in the bed) already during manufacture of the patient support apparatus. Alternatively, the detection belts may be installed on an accessory device for the patient support apparatus and subsequently connected either wirelessly or via a cable to the existing control unit of such patient support apparatus, or such accessory device may have its own external control unit, which is connected to the patient support apparatus as an external anti-collision safety system along with a controller for such given patient support apparatus. Controlling and configuration of the entire system is provided by a controller, which may be an integral part of the patient support apparatus, or it may be an external controller that communicates wirelessly or wired with the control unit of the patient support apparatus and the detection belts of the anti-collision safety system and the patient support apparatus. Communication between individual components of the system can be facilitated using various types of wireless connections such as Bluetooth, Wi-Fi, 5G networks, tags of various types and frequencies, SIM cards, or through various types of transmitters and receivers built into or connected to the detection belts and / or the control unit. These connections can be in communication with either the control unit of the multi-purpose anti-collision safety system as well as the control unit of the patient support apparatus to which such safety and detection system is attached, unless it is directly integrated into the control unit of the patient support apparatus itself. The detection belts can communicate wirelessly with the existing control of the patient support apparatus using any known wirelessmethod, but they may also be attached directly to the control unit that is connected to the controller (control panel) or remote controller of the patient support apparatus.

[0028] The control unit of the patient support apparatus or the control unit of the anti¬ collision safety system can also be connected wirelessly in various ways (such as Bluetooth, Wi-Fi, 5G networks, tags of various types and frequencies, SIM cards, and various types of transmitters and receivers) to the nurse station or central control room of a healthcare facility, which is responsible for monitoring movements of patients or patient support apparatuses within the facility.

[0029] List of Drawings

[0030] Fig. 1 shows various types of patient support apparatuses or beds, in the following order:

[0031] Fig. 1a) shows a hospital bed

[0032] Fig. 1b) shows a birthing bed

[0033] Fig. 1c) shows a paediatric medical bed

[0034] Fig. 2 shows a schematic connection of the anti-collision safety system.

[0035] Fig. 3 shows a cross-section of the structure of the detection (sensing or sensory) belt.

[0036] Fig. 4 shows the end of the detection belt with power supply connection.

[0037] Exemplary Embodiments of the Invention

[0038] Fig. 1 shows various patient support apparatuses 1 (hereinafter referred to also as “beds"), such as a hospital or nursing bed in Fig. 1a, a birthing bed in Fig. 1b, and a paediatric medical bed in Fig. 1c. Patient support apparatuses also include emergency medical stretchers and similar equipment All of these patient support apparatuses may comprise an anti-collision safety system 16.

[0039] Fig. 1 a shows a patient support apparatus 1, which typically comprises side rails 2, headboards and footboards 3, and a support deck 4, which is divided into parts and attached to a frame 5 of the support deck 4. The support deck 4 comprises a plurality of pivotably connected sections or parts, such as e.g. a back section or a backrest part, a seat section or sitting part, and a leg section and a foot section of the support deck4. The individual sections of the support deck 4 are controlled by positioning mechanisms (not shown). The frame 5 of the support deck 4 is attached to a lifting mechanism 6. In this embodiment, the lifting mechanism 6 is a scissor mechanism, however, in another embodiment other mechanisms such as manual, electric, or hydraulic telescopic columns may be used. The number of columns may vary depending on the design of the patient support apparatus 1, for example, 2, 3, or 4 columns. On the opposite side, the lifting mechanism 6 is attached to an undercarriage by using an undercarriage frame 7 further comprising casters 8. In various alternatives, the undercarriage may comprise a fifth wheel 9, which is either a driven wheel or a guided wheel. All casters 8 comprise a brake control pedal 10. The brake control pedals 10 for the casters 8 are used to release or lock movement of the patient support apparatus 1.. In case when the patient support apparatus 1 comprises the fifth wheel 9, the undercarriage frame 7 may comprise additional pedals or foot controls. These pedals are used to control lowering and retracting of the fifth wheel 9, or to control the lifting mechanism 6 of the patient support apparatus 1. The patient support apparatus further comprises controllers 11 located on side rails 2 or headboards 3. These controllers 11 are part of the patient support apparatus and can be of various forms, such as a display 12, a keyboard (not shown), or a combination of a display and a keyboard (not shown). Alternatively, the controllers 11 may be portable and free attached to a part of the patient support apparatus 1 using various types of mounts, hooks, brackets or clips. All such controllers 11 are connected to various types of bed positioning mechanisms, which are controlled by a control unit 13 of the patient support apparatus 1. The control unit 13 is not visible in this figure, however, in most of the patient support apparatuses 1, the control unit 13 is located either under the cover of the undercarriage frame 7 or under the frame 5 of the support deck 4. In another embodiment, the control unit 13 may be a part of the controller 11, or the control unit 13 and the controller 11 may be integrated into the side rails 2 or headboards 3.

[0040] The second type of a patient support apparatus shown in Fig. 1b is a birthing or delivery bed 1. The birthing bed 1 comprises a divided support deck 4, further comprising a seat section and a back section, however, additional necessary components, such as a foot section for supporting the legs in various positions, may be attached to the support deck 4. The support deck 4 is attached to a frame 5 of support deck 4, which is connected to a lifting mechanism 6, the lifting mechanism 6 isfurther attached to the undercarriage 15 or the undercarriage frame 7, depending on the type of the birthing bed T The undercarriage 15 or undercarriage frame 7 of the birthing bed 1 may comprise a kinematic handling wheel (not shown) to move such bed. The undercarriage frame 7 or the frame 5 of the support deck 4 of the birthing bed 1 and other positioning mechanisms of the bed comprise covers 14. Similarly, as the patient support apparatus 1 in Fig. 1a, the birthing bed 1 also comprises brake control pedals 10 (not shown) and controllers 11 (not shown), which are connected to a control unit 13 (not shown) which controls all positioning mechanisms as well as the lifting mechanism 6 of the birthing bed 1. In this embodiment, the control unit 13 may be located under the cover 14.

[0041] The Fig. 1c shows a patient support apparatus 1, which is a children’s bed 1 The children's bed 1 comprises headboards and footboards 3, side rails 2, and a support deck 4. The support deck 4 can comprise several articulating parts that can be pivotably positioned, for example a back part, a seat part, or a leg part. These parts of the support deck 4 can be positioned in most beds using electrically controlled motors or positioning mechanisms to a chair position, or it is possible to lift or position only such part of the support deck 4 that is needed for the patient. A frame 5 of the support deck 4 is attached to an undercarriage frame 7 using a lifting mechanism 6, such as telescopic or electric columns. The undercarriage frame 7 comprises casters 8. The casters 8 are preferably controlled both mechanically and electronically. The undercarriage frame 7 may also comprise so-called a fifth wheel 9, which may be either driven, or it may be a mechanical guiding fifth wheel. In both cases, the fifth wheel 9 is attached to a controller 11 (not shown) and a control unit 13 (not shown), connection of the fifth wheel 9 is also not visible in this figure.

[0042] All of the patient support apparatuses 1 described above and shown in Figs.

[0043] 1a-1c, are patient support apparatuses where undesirable risky situations occur or may occur, such as pinching of a limb of a patient or staff, also a risk of collision with a part of an accessory device or damage to a part of the patient support apparatus caused by impact with an accessory device suspended from the patient support apparatus or located under or between the support deck 4 of the patient support apparatus. Accessory devices include, for example, oxygen bottles, IV poles, tubes, cleaning or diagnostic devices, parts of which may be suspended from the frame 5 of the support deck 4 of the patient support apparatus 1 or located under the patientsupport apparatus 1. Alternatively, certain control devices may become lodged in the spaces between the support deck 4 and the side rail 2 or headboards 3. Likewise, remote controllers or other controllers 11 may be improperly hung on the frame 5 of the support deck 4, and when operating the patient support apparatus 1 using other controllers 11 on the side rail 2, the remote controller 11 may be damaged or rendered inoperable if it becomes trapped between two parts of the patient support apparatus or parts of the frame 5 of the support deck 4 of the patient support apparatus and the undercarriage frame 7. In such cases, it is desired that the patient support apparatus comprises some anti-collision safety system 16 that is small, inexpensive and fast responding to a detected obstacle, and at the same time capable of effective response to dangerous events depending on the assessed situation.

[0044] Therefore, an anti-collision safety system 16 has been developed. This system can either be incorporated into patient support apparatuses 1 or can be installed on patient support apparatus 1 as an external anti-collision safety system 16. The anti¬ collision safety system 16 is disclosed and illustrated in the figures as follow.

[0045] Fig. 2 shows at least one embodiment of an anti-collision safety system 16 of a patient support apparatus 1. The anti-collision safety system 16 comprises a plurality of safety detection belts 17 mutually interconnected by connectors 18. The anti¬ collision safety system 16 also comprises an expander 19, which is either a part of a control unit 13 of the patient support apparatus 1 or it is located outside the control unit 13. Communication between the expander 19 and the control unit 13 can be analogue or digital. Common output from the detection belts 17 is combined in one connector 18, which is connected to the expander 19 or directly to the control unit 13. The connector 18 comprises two conductors. Each detection belt 17 can be disconnected individually for easier maintenance. The expander 19 has an impact on the output level of the signal from the detection belts 17 depending on the input level. The result is an increase in the dynamic range of the original signal. The expander 19 can be a standalone device or a component of any other device or software algorithm or a module (plug-ins) for processing signals in digital form. The expander 19 can be a part of the control unit 13. The control unit 13 can be connected to a controller 11 of the patient support apparatus 1 shown in figures 1a-1c. Alternatively, the control unit 13 may be a standalone unit to which the controller 11 is connected. The controller 11 may be integrated in the patient support apparatus 1 or can be a remote controller ora part of another security device located in a nurse’s room in the healthcare facility (e.g. a hospital), where patient needs are monitored. This means that the control unit 13 can be wired or wireless connected either to the control unit 13 of the patient support apparatus 1 or can be wired or wireless connected to the nurse’s room of the healthcare facility (hospital, care home, etc.).

[0046] The safety detection belts 17 can be connected in parallel or in series with the connectors 18, depending on the design and where the detection belts 17 are installed on the support deck 4 or in the patient support apparatus 1. Also a function of the anti¬ collision safety system 16 matters, i.e. whether the anti-collision safety system 16 is designed to secure the patient support apparatus 1 against an obstacle that prevents moving the patient support apparatus 1 from a point A to a point B, or if the anti-collision safety system 16 is designed to stop moving of the patient support apparatus 1 in relation to the undercarriage 15 or the undercarriage frame 7 of the patient support apparatus 1. Another function of use of the anti-collision safety system 16 is to secure the moving parts of the patient support apparatus 1 in relation to other devices being in vicinity of the patient support apparatus 1 or to prevent collision with an obstacle placed inadvertently in the space between the individual moving parts of the patient support apparatus 1, such as side rails 2, the adjustable pivotably movable parts of the support deck 4 (e.g. the backrest part, foot part, seat part), the lifting mechanism 6 and the undercarriage frame 7, etc. Another function of anti-collision safety system 16 may also be a device for sensing changes in patient’s position or a patient leaving the patient support apparatus to reduce risks of patient's fall or leaving the patient support apparatus 1.

[0047] Fig. 2 shows an anti-collision safety system 16 comprising a detection belt 17, a connector 18, an expander 19, a control unit 13 and a controller 11. The preferred embodiment shown in Fig. 2 discloses an anti-collision safety system 16 comprising safety detection belts 17 interconnected by connectors 18. The detection belts 17 are subsequently connected to the expander 19, the control unit 13 and the controller 11. The expander 19 can be a part of the control unit 13 or can be separated outside the control unit 13. The anti-collision safety system 16 can be installed on the frame 5 of the support deck 4 or on the bottom side of the surface deck 4, which is adjustable. Alternatively, the anti-collision safety system 16 can be installed on the undercarriage frame 7 of all the types of patient support apparatuses 1. In other embodiment, theanti-collision safety system 16 can be installed on the outer edges of the side rails 2 or headboard or footboards 3 as a system that stops the patient support apparatus 1 when moving with use of a driven fifth wheel 9.

[0048] In another embodiment, the anti-collision safety system 16 can be installed on the inner edges of the side rails 2 or headboards or footboards 3 as a system that stops a movable part of the frame 5 of the support deck 4 of the patient support apparatus 1. when moving in relation to the side rail 2 or any headboard or footboard 3 of the patient support apparatus 1.

[0049] The described embodiments of the anti-collision safety system 16 can be installed on any part of a patient support apparatus that moves relative to another movable part of the patient support apparatus, such as a frame 5 of a support deck 4, an undercarriage frame 7, or any pivotably articulating part of the support deck 4, such as a backrest part, a seat part, a foot part or a leg part. All the adjustable movable parts comprise positioning mechanisms that are electrically connected to a control unit 13 of the patient support apparatus. The electronic control unit 13 is also connected to the anti-collision safety system 16. At least one detection belt 17 is connected to the control unit 13, which is connected to at least one controller 11 or a display 12 of any type of a patient support apparatus 1 disclosed herein.

[0050] The Fig. 3 shows a structure or a cross-section of a detection belt 17, which comprises an outer silicone film or housing 20 (i.e. a cover), which surrounds an upper metal strip 21 and a bottom metal strip 22. Between the upper metal strip 21 and the bottom metal strip 22 is a conductive film 23, wherein the upper metal strip 21 and the bottom metal strip 22 comprise a self-adhesive layer 24 on the outer side of each strip, by which these strips 21, 22 are attached to the silicone housing 20. The silicone housing 20 of the detection belt 17 comprises an upper and lower silicone layer and two side silicone layers. The silicone housing 20 of the detection belt 17 is waterproof and flexible, and comprises, at least on one side, a connecting part 25. which is a sticky or self-adhesive layer that allows the detection belt 17 to be attached to any part of the patient support apparatus for detecting an obstacle, or detecting a collision with an undesired object that may be in the way of the movement of any part of the patient support apparatus 1 or the entire patient support apparatus.Alternatively, the detection belt 17 may be inserted into a groove or a slot of the patient support apparatus 1 or into fixing bars or rods of the patient support apparatus 1, which will keep the detection belt 17 in place on the relevant part of the patient support apparatus 1- Fig. 4 shows a plan view (i.e. a top view) of the end part of a detection belt 17 without an outer silicone housing 20 (not shown), in which the detection belt 17 is located. The inner part of the detection belt 17 comprises an upper metal strip 21 and a bottom metal strip 22, between which a partially conductive plastic film 23 is located. All these parts are sealed together with power connection in the silicone housing 20 (not shown). The bottom metal strip 22 is connected to power connection 26 at the lower side of this strip 22, and the second power connection 26 is connected to the upper metal strip 21. Both power connections 26 are connected to a control unit 13.

[0051] Such designed detection belt 17 acts as a force-sensitive resistor (a variable resistor). Depending on the force applied from the outside on the detection belt 17, a plastic conductive film 23 is compressed, by which flow of electric current between an upper metal strip 21 and a bottom metal strip 22 and through the conductive film 23 increases. Electric current passes through power connection 26 and through conductive film 23 of the detection belt 17 constantly when the detection belt 17 is connected to the power supply source, i.e. to a control unit 13 of a patient support apparatus T

[0052] Increased electric current flow results in a change of electric resistance in the detection belt 17, respectively initial electric resistance decreases, but will never be zero. A control unit 13 comprising a software module which assesses this reduction as an obstacle having a certain weight applied on the surface of the detection belt 17 on the sensing side and activates the positioning mechanisms on the patient support apparatus 1 to act accordingly as disclosed previously herein. The software module is located either in the control unit 13 or together with the control unit 13 in a controller 11 or a display 2,

[0053] The anti-collision safety system 16 enables detection of a plurality of states. The anti-collision safety system 16 may detect an obstacle, absence of an obstacle, a light press or unintentional contact with the detection belt 17, or a fault or damage to the detection belt 17 itself.Detection of an obstacle occurs if at least one detection belt 17 is in contact with an obstacle. Detecting an obstacle is recognized by a software module in a control unit 13 based on the size of the electrical resistance in the detection belt 17. In other words, the control unit 13 software senses pressure on any part of the detection belt 17 and if pressure is sensed, information of detecting an obstacle is notified. Consequently, the control unit 13 stops moving of the relevant adjustable or movable part of the patient support apparatus 1 where pressure is sensed, therefore an obstacle detected, or returns such adjustable or movable part of the patient support apparatus 1 to its original position.

[0054] Similarly, the anti-collision safety system 16 detects light or unintentional contact with the detection belt 17. The control unit 13 evaluates size of the electric current in the detection belt 17, which is small in such case, and sends signal to a relevant appropriate positioning mechanisms of the patient support apparatus 1 only to stop movement of an appropriate adjustable or movable part and alerts the caregiver to check the status of the patient support apparatus 1- The error and change in resistance in the detection belt 17 is not permanent in this case.

[0055] Another state that an anti-collision safety system 16 may detect is disconnection or interruption of at least one of plurality of detection belts 17. When at least one of the detection belts 17 is disconnected, the total measured resistance increases due to the parallel connection of the detection belts 17. The anti-collision safety system 16 detects a serious fault in the detection belt 17 and records an error state in the database of a control unit 13, or the control unit 13 can send an error message indicating that the fault is permanent. The anti-collision safety system 16 is also capable of detecting disconnection of a plurality of detection belts 17. If all detection belts 17 are disconnected simultaneously, the protection of the control unit 13 reacts and starts to saturate the A / D converter gradually. The anti-collision safety system 16 detects a serious fault in the detection belts 17 and records it as an error in the database of the control unit 13, or the control unit 13 sends a signal to a controller 11 or a display 2, or directly to the patient support apparatus 1- It should be understood that the invention has been explained and illustrated as an exemplary embodiment. However, it must be understood that the invention may bepracticed otherwise than as specifically explained and illustrated without departing from its scope.

[0056] It is to be appreciated that the terms “include”, “includes”, and “including” have the same meaning as the terms “comprise”, “comprises", and “comprising”. The terminology which has been used is intended to be in the nature of words of description rather than limitations.

[0057] List of References

[0058] 1 - Patient support apparatus

[0059] (hospital bed, children bed, birthing bed etc.)

[0060] 2 - Side rail

[0061] 3 - Headboard or footboard

[0062] 4 - Support deck

[0063] 5 - Frame (of support deck)

[0064] 6 - Lifting mechanism

[0065] 7 - Undercarriage frame

[0066] 8 - Casters

[0067] 9 - Fifth wheel

[0068] 10 - Brake control pedal

[0069] 11 - Controller

[0070] 12 - Display

[0071] 13 – Control unit

[0072] 14 – Cover

[0073] 15 – Undercarriage

[0074] 16 - Anti-collision safety system

[0075] 17 – Detection belt

[0076] 18 – Connector

[0077] 19 - Expander

[0078] 20 - Silicone housing (external cover of the detection belt)

[0079] 21 - Upper metal strip22 – Bottom metal strip 23 - Conductive film 24 - Self-adhesive layer 25 - Connecting part 26 - Power connection

Claims

CLAIMS1. An anti-collision safety system (16) for detecting obstacles on a patient support apparatus (1), characterized in that the anti-collision safety system (16) comprises at least one detection belt (17) connected by a connector (18) to at least one other detection belt (17), which are connected via an output connector (18) to a control unit (13), preferably via an expander (19), wherein the control unit (13) is connected by wire or wirelessly to at least one controller (11), wherein the detection belts (17) are attached to at least one side or a part of the patient support apparatus (1 ) that moves relative to another side or a part of the patient support apparatus (1).

2. The anti-collision safety system (16) for detecting obstacles on the patient support apparatus (1 ) according to claim 1, characterized in that the detection belts (17) are connected in parallel or in series with the connector (18).

3. The anti-collision safety system (16) for detecting an obstacle on the patient support apparatus (1) according to claim 1, characterized in that at least one detection belt (17) is connected to the expander (19), wherein the expander (19) is either part of the control unit (13) or is located outside the control unit (13).

4. The anti-collision safety system (16) for detecting an obstacle on the patient support apparatus (1), according to any of claims 1 to 3, characterized in that the detection belt (17) is a force-sensitive resistor.

5. The anti-collision safety system (16) for detecting an obstacle on the patient support apparatus (1 ), according to any of claims 1 to 4, characterized in that at least one detection belt (17) is connected to at least one part of an adjustable support deck (4) of the patient support apparatus (1).

6. The anti-collision safety system (16) for detecting an obstacle on the patient support apparatus (1), according to claim 5, characterized in that at least one detection belt (17) for detecting obstacles and subsequent stopping of movement of any positioning part of the support deck (4) of the patient supportapparatus (1 ), connected to the bottom side of such positioning part of the support deck (4), is directly connected to the control unit (13) via an output connector (18).

7. The anti-collision safety system (16) for detecting an obstacle on the patient support apparatus (1), according to any of claims 1 to 6, characterized in that at least one detection belt (17) for detecting and stopping of movement of the patient support apparatus (1) is located on at least one part of a side rail (2), a headboard (3) or the outer edge of a frame (5) of the support deck (4) of the patient support apparatus (1 ).

8. The anti-collision safety system (16) for detecting an obstacle on the patient support apparatus (1), according to any of claims 1 to 6, characterized in that at least one detection belt (17) for evaluating a change of position of a patient on the patient support apparatus (1) using the control unit (13) is connected to at least one part of the upper side of the support deck (4) of the patient support apparatus (1),

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