GB2549475A - Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell - Google Patents
Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell Download PDFInfo
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- GB2549475A GB2549475A GB1606700.1A GB201606700A GB2549475A GB 2549475 A GB2549475 A GB 2549475A GB 201606700 A GB201606700 A GB 201606700A GB 2549475 A GB2549475 A GB 2549475A
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- Prior art keywords
- coupling
- patient support
- load
- patient
- coupling member
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G7/00—Beds specially adapted for nursing; Devices for lifting patients or disabled persons
- A61G7/05—Parts, details or accessories of beds
- A61G7/0527—Weighing devices
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G7/00—Beds specially adapted for nursing; Devices for lifting patients or disabled persons
- A61G7/10—Devices for lifting patients or disabled persons, e.g. special adaptations of hoists thereto
- A61G7/104—Devices carried or supported by
- A61G7/1042—Rail systems
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G7/00—Beds specially adapted for nursing; Devices for lifting patients or disabled persons
- A61G7/10—Devices for lifting patients or disabled persons, e.g. special adaptations of hoists thereto
- A61G7/1073—Parts, details or accessories
- A61G7/108—Weighing means
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
- B66C13/00—Other constructional features or details
- B66C13/16—Applications of indicating, registering, or weighing devices
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
- G01G19/14—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups for weighing suspended loads
- G01G19/18—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups for weighing suspended loads having electrical weight-sensitive devices
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G19/00—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups
- G01G19/44—Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups for weighing persons
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G23/00—Auxiliary devices for weighing apparatus
- G01G23/005—Means for preventing overload
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01G—WEIGHING
- G01G3/00—Weighing apparatus characterised by the use of elastically-deformable members, e.g. spring balances
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G2203/00—General characteristics of devices
- A61G2203/30—General characteristics of devices characterised by sensor means
- A61G2203/40—General characteristics of devices characterised by sensor means for distance
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- Health & Medical Sciences (AREA)
- Nursing (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Invalid Beds And Related Equipment (AREA)
Abstract
The coupling 10 has a disc spring 18 between a plate 12 with an aperture 22, a second member 14 with a hole 34, a connecter 20 passes through the holes to maintain alignment of the plates when they are moved relative to each other. Preferably the disk spring is a stack 16 of five Belleville washers arranged in alternating series, which is partially housed in a cavity (fig.2,24) of the plate, and sits on the second member. The second member may have a slot 36 for attaching a displacement measurement device such as a linear potentiometer. The connector may be a bar with a base plate 44 and a removable lock member 50 to prevent axial decoupling. The coupling may form part of a load cell in a motorised patient hoist (fig.4,100), located between an adaptor plate (fig.4,166) of a rail bogie (fig.4,164) and the carriage body (fig.4,158); or a load cell may be provided for each leg of a bed frame. A method of determining a load by measuring displacement is also claimed.
Description
Load-Determining Patient Ceiling-Hoist Carriage, Bed Apparatus, Patient Support Coupling and Load Cell
The present invention relates to a patient support coupling for a patient support device, and in particular but not necessarily exclusively for a patient ceiling-hoist carriage device. The invention further relates to a load cell having such a patient support coupling, and to load-determining patient support device having said load cell incorporated therein, and also to a method of determining a load applied to a loaddetermining patient support device.
For support devices which support patients, particularly those having mobility impairments, it is important to be aware of the maximum load applied to the device so as to avoid catastrophic failure of the equipment. This is particularly important for scenarios in which a patient is elevated, and therefore could be readily injured in the event of a failure.
Patient hoists may be provided which are generally attached to a ceiling mounted rail-guided carriage for moving the patient between set locations. The patient is suspended from the hoist to render travel straightforward. Traditionally, the load on the carriage has been measured by providing an electronic motor gearbox. As the load on the device increases, the motor will be required to draw more current in order to maintain a position of the device. This current can be monitored, and the load on the device inferred.
However, this is an inefficient means of measuring the load on the device, since there will be a constant draw of current by the motor. Furthermore, the measurement is relatively inaccurate; a high current may still be provided even in the event of a low load, and thus the electronic load measurement is non-linear with respect to load.
The present invention seeks to provide a load cell which overcomes the above-referenced problems.
According to a first aspect of the invention, there is provided a load-determining patient ceiling-hoist carriage comprising: a carriage body; a patient ceiling-hoist connector connected to the carriage body and with which a patient ceiling-hoist is engagable; a load cell comprising: a patient support coupling having: a first coupling member having a first aperture therethrough; a second coupling member having a second aperture therethrough, the first coupling member being displaceable relative to the second coupling member; a disc spring element positioned between the first and second coupling members; and a connector element, the connector element being receivable through the first and second apertures so as to maintain an axial alignment of the first and second coupling members; and a displacement measurement device arranged to measure a relative displacement between the first and second coupling members of the patient support coupling; and a displacement measurement device being fixedly connected relative to the carriage body and being engaged with the second coupling member of the patient support coupling, the displacement measurement device being arranged to determine a load applied to the patient support device by measuring a relative displacement between the first and second coupling members of the patient support coupling.
The patient support device may further comprise a bogie having an adapter plate for connection to the carriage body, the adapter plate being connectable via the connector element of the patient support coupling. A spring may be provided which is receivable about the connector element of the patient support coupling and which is positionable between the adapter plate and the carriage body. An electrically-operable motor may also be provided which is in drivable engagement with the bogie. The displacement measurement device may include a linear potentiometer, and the or each patient support coupling may be releasably engagable with the carriage body.
According to a second aspect of the invention, there is provided a load-determining bed apparatus comprising: a bed frame having a plurality of ground support elements; and a plurality of load cells associated with the hed frame, each load cell comprising: a patient support coupling having: a first coupling member having a first aperture therethrough; a second coupling member having a second aperture therethrough, the first coupling member being displaceable relative to the second coupling member; a disc spring element positioned between the first and second coupling members; and a connector element, the connector element being receivable through the first and second apertures so as to maintain an axial alignment of the first and second coupling members; and a displacement measurement device arranged to measure a relative displacement between the first and second coupling members of the patient support coupling; the displacement measurement device being fixedly connected relative to the carriage body and being engaged with the second coupling member of the patient support coupling, the displacement measurement device being arranged to determine a load applied to the patient support device by measuring a relative displacement between the first and second coupling members of the patient support coupling.
Each of the plurality of load cells may be associated with a ground support element of the bed frame Preferably, the displacement measurement device may be a linear potentiometer, and the or each load cell may be releasably engagable with the bed frame.
By incorporating a patient support coupling into a patient support device, an operator can ensure with great accuracy whether a particular device is due for maintenance, or whether a critical maximum load has been exceeded which may have damaged the device. This advantageously limits the likelihood of a catastrophic failure of the patient support device.
According to a third aspect of the invention, there is provided a patient support coupling for a patient support device, the patient support coupling comprising: a first coupling member having a first aperture therethrough; a second coupling member having a second aperture therethrough, the first coupling member being displaceable relative to the second coupling member; a disc spring element positioned between the first and second coupling members; and a connector element, the connector element being receivable through the first and second apertures so as to maintain an axial alignment of the first and second coupling members.
By providing a patient support coupling in which a disc spring element provides the necessary resistance to compression allows for the patient support coupling to provide an accurate and linear relationship between the displacement between the first and second coupling members and the load applied. The connector element serves to ensure a smooth and accurate axis of displacement. In doing so, the patient support coupling provides the accuracy required for critical patient support situations without requiring a constant application of current.
Preferably, the disc spring element may be provided as a stack of disc springs, which may be arranged in an alternating series. The disc spring element may most preferably include five disc springs. Optionally, the disc spring element may be adapted to provide linear displacement for loads up to 300kg.
Various improvements can be made to the disc spring element, either to change a range over which a displacement is measured, changing the spring constant, or the resistance to compression, which can be tailored to a particular loading requirement.
The first coupling member may include a cavity into which the disc spring element is at least in part receivable. Additionally or alternatively, the second coupling member may include an upper surface which defines a spring seat which is complementarily engagable with the disc spring element.
The shapes of the first and second coupling members can be formed so as to beneficially receive the disc spring element, thereby simplifying the ease of assembly of the patient support coupling, and ensuring a consistent application of force across the patient support coupling each time a load is applied.
The second coupling member may include an engagement element for coupling to a displacement measurement device associated with the patient support coupling, which may preferably be an engagement slot for receiving a connector of a linear potentiometer. A linear potentiometer provides a simple means of determining a linear displacement of the patient support coupling, allowing the result of the displacement to be readily output.
Preferably, the connector element may be formed as an elongate bar having a base plate at one end thereof, the base plate being abuttably engagable with the second coupling member in use. A locking element may be provided which is associable with the connector element to prevent or inhibit axial decoupling of the first and second coupling members, and said locking element may be releasably engagable with the connector element.
The connector element not only provides a means of alignment of the whole patient support coupling, ensuring that a direction of travel of the movable patient support coupling member is maintained, but also ensures that the first and second coupling members do not inadvertently displace laterally of one another. The connector element may also advantageously act as a connecting means for connecting the patient support coupling to other components in the patient support device, such as a patient ceiling-hoist carriage device.
According to a fourth aspect of the invention, there is provided a load cell for a patient support device comprising a patient support coupling in accordance with the first aspect of the invention, and a displacement measurement device arranged to measure a relative displacement between the first and second coupling members of the patient support coupling.
According to a fifth aspect of the invention, there is provided a method of determining a load applied to a load cell in accordance with the second aspect of the invention, the method comprising the steps of: applying a load to the load cell; displacing the first coupling member relative to the second coupling member, so as to at least partially compress the spring disc element; and measuring a relative displacement of the first and second coupling members, the relative displacement being proportional to a load applied to the load cell.
The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:
Figure 1 shows a perspective representation of one embodiment of a patient support coupling in accordance with the third aspect of the invention;
Figure 2 shows a cross-section through the patient support coupling shown in Figure 1;
Figure 3 shows an exploded perspective representation of the patient support coupling of Figure 1;
Figure 4 shows a perspective representation of one embodiment of a patient ceiling-hoist carriage device in accordance with the first aspect of the invention, a bogie of the patient ceiling-hoist carriage device being shown separately for clarity; and
Figure 5 shows a longitudinal cross-section through the patient ceiling-hoist carriage device of Figure 4 with the bogie in situ and in engagement with a patient support coupling of the patient ceiling-hoist carriage device.
Referring firstly to Figure 1, there is shown a patient support coupling, which is indicated globally as 10. The patient support coupling 10 includes first and second coupling members 12, 14 which are relatively displaceable, which allows the measurement of a load applied to the patient support coupling 10. The specific interaction between the component parts can be most readily seen in Figures 2 and 3 of the drawings.
As can be seen from Figures 2 and 3, the patient support coupling 10 includes a disc spring element 16, here formed from a plurality of disc springs 18 which are arranged in a stack, and a connector element 20 which is configured to prevent total separation of the first and second coupling members 12, 14, whilst still permitting relative displacement therebetween.
The first coupling member 12 is preferably formed as a plate, as illustrated, and has a first aperture 22 therethrough which is sized so as to permit at least part of the connector element 20 to pass through the first aperture. In the depicted embodiment, the first coupling member 12 includes a cavity 24 within which the disc spring element 16 is at least in part receivable; however, it will be appreciated that such a cavity 24 or recess for seating the disc spring element 16 is not strictly necessary, and could be dispensed with or provided by the use of a discrete spacer, for example.
As shown, the first coupling member 12 has a largely planar upper surface 26, and this may be useful in contexts where a load is applied to the patient support coupling 10 from above. However, this is not a requirement, since the patient support coupling 10 may be arranged so as to measure a dependent load. The first coupling member 12 may preferably, as shown, be provided so as to have one or more locators 28 which are complementarily shaped to engage with the second coupling member 14.
The second coupling member 14 as shown is formed so as to be locatable within an area defined by the locators 28 of the first coupling member 12, and may preferably have a plurality of complementary receptacles 30 for engaging with the locators 28. A body 32 of the second coupling member 14 is here provided so as to have a width which is equal to or similar to that of the first coupling member 12, and a second aperture 34 is provided through the body 32 of the second coupling member 14, and which is, in use, aligned with the first aperture 22.
Furthermore, in the present embodiment, the second coupling member 14 is preferably arranged so as to be the movable member of the patient support coupling 10 with respect to a housing of an object within which the patient support coupling 10 is incorporated, and therefore the body 32 of the second coupling member 14 is provided to include an engagement element 36 which can engage with a displacement measurement device associated with the patient support coupling 10. Here, this engagement element 36 is formed as a depending projection having a slot 38 therethrough, which is suitable for engaging with a corresponding output of a displacement measurement device, such as a linear potentiometer.
The disc spring element 16 is, in the depicted embodiment, provided as a stack of five disc springs 18, also known as Belleville washers or cylindrical disc springs, and are arranged in series, that is, in an alternating configuration. As such that the frusto-conically shaped disc springs 18 contact one another such that the larger ends of the disc springs 18 are touching the larger ends of a neighbouring disc spring 18, or the smaller end of the disc spring 18 contacts the smaller end of its neighbour 18. Such an arrangement may produce the greatest degree of proportionality between the load applied and the displacement of the first and second coupling members 12, 14. Preferably, the disc springs 18 may be formed from a flexible metal, but other materials could be considered, such as elastomeric or rubber materials.
An upper surface 40 of the second coupling member 14 may be formed as a seat which is complementarily shaped to the disc spring element 16, so as to permit the latter to be seated on the second coupling member 14.
The connector element 20 is provided so as to interconnect the first and second coupling members 12, 14, in particular along the axis of displacement. In the depicted embodiment, the connector element 20 is provided as an elongate bar 42 having a base plate 44 at a first end, and an engagement hole 46 diametrically through an opposite end of the bar 42. This is merely one form of the connector element 20, and other coupling arrangements could be considered, for instance, by using a screw-threaded fastener having sufficient slack to permit relative displacement of the first and second coupling members 12, 14. An outer surface of the connector element 20 may be coated or otherwise treated so as to minimise frictional forces upon contact with either of the first and second coupling members 12, 14.
The second coupling member 14 may be provided with a recess 48 on a lower surface thereof which is complementarily shaped to the base plate 44 of the connector element 20. If the base plate 44 is non-circular, for instance, having an obrounded profile as can be best seen in Figure 3, then complementary engagement between the second coupling member 14 and the base plate 44 may act to prevent accidental rotation of the connector element 20 in use.
To assemble the patient support coupling 10, the bar 42 of the connector element 20 can be inserted through the second aperture 34 of the second coupling member 14, with the base plate 44 seating in the recess 48 of the second coupling member 14. The spring disc element 16 can then be engaged over and around the bar 42 of the connector element 20 so as to seat on the upper surface 40 of the second coupling member 14.
It is then possible to insert the bar 42 through the first aperture 22 of the first coupling member 12, which may preferably have the effect of the disc spring element 16 being seated within the cavity 24 of the first coupling member 12, thereby limiting the potential for lateral displacement of the spring disc element 16. This assembly should then leave at least part of the bar 42 extending above the upper surface 26 of the first coupling member 12, and in particular such that the engagement hole 46 is entirely exposed above the upper surface 26. This allows a locking element 50, such as the depicted peg, to be inserted into the engagement hole 46 and which thereby holds the first coupling member 12 captive on the connector element 20.
As illustrated, a separation may also be provided between the upper surface 26 of the first coupling member 12 and the locking element 50. In the depicted embodiment, this is illustrated as a spiral spring 52 and washer 54, which provide some resistance to compression and serve to retain the first coupling member 12 in position.
Whilst the locking element 50 is described above as being a peg, this is not the only means by which the first coupling member 12 may be retained on the connector element 20, and other arrangements may be apparent to the skilled person. For example, a clip or latched arrangement could be provided.
In use, the patient support coupling 10 is able to provide an accurate indication of a load applied thereto. The first and second coupling members 12, 14 are relatively displaceable to one another, and by using a spring disc element 16 to provide resistance between the first and second coupling members 12, 14, a linear relationship is output between the load applied and the relative displacement of the first and second coupling members 12, 14. As such, if one of the first or second coupling members 12, 14 is positionally fixed, then the displacement of the other can be measured, and, if suitably calibrated, the load applied can be determined.
For certain uses, it is important that the linearity between displacement and applied load be maintained over a wide range. This is particularly important where significant loads are applied in delicate situations, never more so than for the supporting of a patient; if a patient support device were to undergo catastrophic failure to a load-bearing component, then this could result in injury to the patient. As such, it is very important that the load applied is accurately known, and over a range which might be appropriate in context.
For patients with mobility impairments, it is possible to provide a patient hoist, which allows for a patient to be transported without self-ambulation. Such hoists are typically mounted from a ceiling rail, and this mounting is achieved via a patient ceiling-hoist carriage device, such as that indicated in Figure 4 at 100. Since the patient ceiling-hoist carriage device is ceiling-mounted, there is significant risk or hazard of overloading and breaking the system. Typically, such devices are required to be operational up to and including a load of 300kg, inclusive of the patient and the associated hoist.
The patient ceiling-hoist carriage device 100 will typically comprise a carriage 156 having a carriage body 158, which may optionally incorporate motorised components if used or required, and will also have a hoist connection means via which a patient can be hoisted. This is indicated by the engagement arm 160 in Figure 4. The load on the patient ceiling-hoist carriage device 100 will therefore be applied through this engagement arm 160. An emergency stop cord 162 may be provided to allow the carriage 156 to be halted as necessary, but no load would ordinarily be provided via this cord 162.
At the top of the patient ceiling-hoist carriage device 100 is provided a bogie 164, shown separated from the carriage body in Figure 4. This may be releasably engagable with the carriage 156 to allow for separate maintenance of the individual components. The bogie 164 may be provided with a discrete baseplate 166 via which the bogie 164 can be engaged with the carriage body 158.
The bogie 164 may be provided with a plurality of castor wheels 168, which may be non-drivable, or drivable by, for example, an associated electrically-operable motor, to allow the patient ceiling-hoist carriage device 100 to be navigated along one or more ceiling-mounted rails.
The incorporation of the patient support coupling 10 into the patient ceiling-hoist carriage device 100 can be seen in Figure 4. The patient support coupling 10 is inserted inside and extends through the carriage body 158. The precise arrangement of the patient support coupling 10 in this particular embodiment can be seen in Figure 5 of the drawings, which indicates a cross-section through the patient ceiling-hoist carriage device 100 along the centreline of the bogie 164, shown in engagement with the carriage 156.
The bogie 164 has front and rear wheel sections 170, 172 which are spaced apart from one another and connected to the baseplate 166. In the depicted embodiment, the baseplate 166 has a central opening 174 though which, as shown, the connector element 20 may be inserted. Once the locking element 50 has been engaged with the connector element 20 following insertion through the opening 174 then it may be possible to lock the patient support coupling 10 in place relative to the baseplate 166, thereby joining the bogie 164 to the patient support coupling 10. Other means of attachment may be provided, however, such as threaded fasteners or similar, or the patient support coupling 10 may be provided so as to be in permanent engagement with the baseplate 166. A linear potentiometer 176 or similar displacement measurement device, such as an optical sensor, may be provided within the carriage body 158 so as to be engageable with the patient support coupling 10 once installed, typically via the engagement element 36. The first coupling member 12 may then be affixed, preferably releasably, to the carriage body 158, with the second coupling member 14 being displaceable relative to the carriage body 158. In combination with one another, the displacement measurement device and patient support coupling 10 form a load cell, capable of measuring a load applied to the patient support device.
In practical application, the load on the patient ceiling-hoist trolley device 100 will be such as to apply a force onto the carriage 156. As such, in relative terms, it will likely be the carriage body 158 which is in fact moving relative to the second coupling member 14. As a load is applied, the first coupling member 12 will be displaced, compressing the disc spring element 16, thereby creating a measurable displacement at the potentiometer 176. Since the compression of the disc spring element 16 is linear over a large load range, this results in accurate determination of the load which is applied to the patient ceiling-hoist carriage device 100 over time.
This patient support coupling 10 can then be coupled to a controller or processor which is arranged to monitor, record and/or process information regarding the load applied to the patient ceiling-hoist carriage device 100, and therefore provide an accurate indication of, for example, whether maintenance is required, or whether a maximum operational load has been exceeded and therefore whether the patient ceiling-hoist carriage device 100 should be replaced.
Whilst the patient ceiling-hoist carriage device 100 is, in the present embodiment, the intended use of the patient support coupling 10 in context, it will be apparent to the skilled person that such a patient support coupling 10 could be provided in many other contexts where a patient is supported.
By way of example only, there may be provided a load-determining bed apparatus, which has a bed frame having a plurality of ground support elements, such as legs or castors, and a mattress upon which a patient can rest. The load-determining bed apparatus may then have a plurality of patient support couplings 10, preferably located at each ground support element so as to provide an accurate indication of the load on the bed. Such an arrangement may be of particular use in combination with a patient ceiling-hoist carriage device 100, wherein a person is transferred between a loaddetermining bed apparatus and another location.
In general, the present invention can provide a method of determining a load applied to a load cell which comprises the steps of applying a load to the load cell, which includes at least one patient support coupling 10, and then displacing the first coupling member 12 relative to the second coupling member 14, so as to at least partially compress the spring disc element 16. A relative displacement of the first and second coupling members 12, 14 is then measured, the relative displacement being proportional to a load applied to the load cell.
It is therefore possible to provide a patient support coupling for accurate measurement of loads applied in critical scenarios, such as those in which a patient is hoisted, and which maintains a linear load-to-displacement ratio over a large range of loads. This can be achieved by using a disc spring element arranged so as to achieved this linearity over a given range, typically up to 300kg to meet safety requirements.
The words ‘comprises/comprising’ and the words ‘having/including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof
It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.
The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.
Claims (26)
1. A load-determining patient ceiling-hoist carriage comprising: a carriage body; a patient ceiling-hoist connector connected to the carriage body and with which a patient ceiling-hoist is engagable; and a load cell comprising: a patient support coupling having: a first coupling member having a first aperture therethrough; a second coupling member having a second aperture therethrough, the first coupling member being displaceable relative to the second coupling member; a disc spring element positioned between the first and second coupling members; and a connector element, the connector element being receivable through the first and second apertures so as to maintain an axial alignment of the first and second coupling members; and a displacement measurement device arranged to measure a relative displacement between the first and second coupling members of the patient support coupling; the displacement measurement device being fixedly connected relative to the carriage body and being engaged with the second coupling member of the patient support coupling, the displacement measurement device being arranged to determine a load applied to the patient support device by measuring a relative displacement between the first and second coupling members of the patient support coupling.
2. A load-determining patient ceiling-hoist carriage as claimed in claim 1, further comprising a bogie having an adapter plate for connection to the carriage body, the adapter plate being connectable via the connector element of the patient support coupling.
3. A load-determining patient ceiling-hoist carriage as claimed in claim 2, further comprising a spring which is receivable about the connector element of the patient support coupling and which is positionable between the adapter plate and the carriage body.
4. A load-determining patient ceiling-hoist carriage as claimed in claim 2 or claim 3, further comprising an electrically-operable motor in drivable engagement with the bogie.
5. A load-determining patient ceiling-hoist carriage as claimed in any one of the preceding claims, wherein the displacement measurement device includes a linear potentiometer.
6. A load-determining patient ceiling-hoist carriage as claimed in any one of the preceding claims, wherein the or each patient support coupling is releasably engagable with the carriage body.
7. A load-determining patient ceiling-hoist carriage substantially as hereinbefore described, with reference to Figures 4 and 5.
8. A load-determining bed apparatus comprising: a bed frame having a plurality of ground support elements; and a plurality of load cells associated with the bed frame, each load cell comprising: a patient support coupling having: a first coupling member having a first aperture therethrough; a second coupling member having a second aperture therethrough, the first coupling member being displaceable relative to the second coupling member; a disc spring element positioned between the first and second coupling members; and a connector element, the connector element being receivable through the first and second apertures so as to maintain an axial alignment of the first and second coupling members; and a displacement measurement device arranged to measure a relative displacement between the first and second coupling members of the patient support coupling; the displacement measurement device being fixedly connected relative to the carriage body and being engaged with the second coupling member of the patient support coupling, the displacement measurement device being arranged to determine a load applied to the patient support device by measuring a relative displacement between the first and second coupling members of the patient support coupling.
9. A load-determining bed apparatus as claimed in claim 8, wherein each of the plurality of load cells is associated with a ground support element of the bed frame.
10. A load-determining bed apparatus as claimed in claim 8 or claim 9, wherein the displacement measurement device includes a linear potentiometer.
11. A load-determining bed apparatus as claimed in any one of claims 8 to 10, wherein the or each load cell is releasably engagable with the bed frame.
12. A patient support coupling for a patient support device, the patient support coupling comprising: a first coupling member having a first aperture therethrough; a second coupling member having a second aperture therethrough, the first coupling member being displaceable relative to the second coupling member; a disc spring element positioned between the first and second coupling members; and a connector element, the connector element being receivable through the first and second apertures so as to maintain an axial alignment of the first and second coupling members.
13. A patient support coupling as claimed in claim 12, wherein the disc spring element is provided as a stack of disc springs.
14. A patient support coupling as claimed in claim 13, wherein the stack of disc springs is arranged in an alternating series
15. A patient support coupling as claimed in claim 13 or claim 14, wherein the disc spring element includes five disc springs.
16. A patient support coupling as claimed in any one of claims 12 to 15, wherein the disc spring element is adapted to provide linear displacement for loads up to 300kg.
17. A patient support coupling as claimed in any one claims 12 to 16, wherein the first coupling member includes a cavity into which the disc spring element is at least in part receivable.
18. A patient support coupling as claimed in any one of claims 12 to 17, wherein the second coupling member includes an upper surface which defines a spring seat which is complementarily engagable with the disc spring element.
19. A patient support coupling as claimed in any one of claims 12 to 18, wherein the second coupling member includes an engagement element for coupling to a displacement measurement device associated with the patient support coupling.
20. A patient support coupling as claimed in claim 19, wherein the engagement element includes an engagement slot for receiving a connector of a linear potentiometer.
21. A patient support coupling as claimed in any one of claims 12 to 20, wherein the connector element is formed as an elongate bar having a base plate at one end thereof, the base plate being abuttably engagable with the second coupling member in use.
22. A patient support coupling as claimed in any one of claims 12 to 21, further comprising a locking element associable with the connector element to prevent or inhibit axial decoupling of the first and second coupling members.
23. A patient support coupling as claimed in claim 22, wherein the locking element is releasably engagable with the connector element.
24. A patient support coupling substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.
25. A load cell for a patient support device comprising a patient support coupling as claimed in any one of claims 12 to 24, and a displacement measurement device arranged to measure a relative displacement between the first and second coupling members of the patient support coupling.
26. A method of determining a load applied to a load cell as claimed in claim 25, the method comprising the steps of: applying a load to the load cell; displacing the first coupling member relative to the second coupling member, so as to at least partially compress the spring disc element; and measuring a relative displacement of the first and second coupling members, the relative displacement being proportional to a load applied to the load cell.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1606700.1A GB2549475A (en) | 2016-04-18 | 2016-04-18 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
GB1618827.8A GB2555652A (en) | 2016-04-18 | 2016-04-18 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
PCT/GB2017/051021 WO2017182773A1 (en) | 2016-04-18 | 2017-04-12 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1606700.1A GB2549475A (en) | 2016-04-18 | 2016-04-18 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2549475A true GB2549475A (en) | 2017-10-25 |
Family
ID=58709494
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1618827.8A Withdrawn GB2555652A (en) | 2016-04-18 | 2016-04-18 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
GB1606700.1A Withdrawn GB2549475A (en) | 2016-04-18 | 2016-04-18 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1618827.8A Withdrawn GB2555652A (en) | 2016-04-18 | 2016-04-18 | Load-determining patient ceiling-hoist carriage, bed apparatus, patient support coupling and load cell |
Country Status (2)
Country | Link |
---|---|
GB (2) | GB2555652A (en) |
WO (1) | WO2017182773A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220133566A1 (en) * | 2020-11-05 | 2022-05-05 | Liko Research & Development Ab | Lift systems with strain gauges incorporated in load beams and methods for operating the same |
US11376180B2 (en) | 2016-12-01 | 2022-07-05 | Liko Research & Development Ab | Gates for overhead lifting rails |
US11579010B1 (en) * | 2019-03-21 | 2023-02-14 | Motion Laboratories, Inc. | Chain hoist with integral load cell |
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Also Published As
Publication number | Publication date |
---|---|
GB2555652A (en) | 2018-05-09 |
WO2017182773A1 (en) | 2017-10-26 |
GB2555652A8 (en) | 2018-05-30 |
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