A DEVICE, SYSTEM AND METHOD FOR MONITORING THE PRESSURE

APPLIED TO A SURFACE BY A SUBJECT

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority on United States Provisional Patent Application Serial Number 62/813,707 filed on March 4, 2019 and incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure generally relates to monitoring the presence of a person on a bed, chair or other surface. More particularly, but not exclusively, the present disclosure relates to a device, system and method for monitoring the pressure applied to a surface by a subject. BACKGROUND

[0003] Care facilities, such a long-term hospital, residential nursing homes and the like must provide protection to patients or residents who may be impaired.

[0004] Accordingly, the art teaches various monitoring systems for such individuals such as pressure pads for use on a chair, bed or other surface occupied by a patient or resident are known, These devices are operatively connected to an alarm system for alerting staff when the patient has moved outside a defined area. The pressure pad may be wireless and connected to a bed pad transmitter, which is in wireless communication with a proximate bed monitor. Multiple pads can be linked to one bed monitor. [0005] Usually, the pad comprises a foam plastic pad and heavy aluminum foil plates laminated on opposite sides of the foam. Pressure on the pad causes the plates to touch indicating that the patient is occupying the pad. When the pressure is released the plates are separated indicating that the pad is no longer occupied. OBJECTS

[0006] An object of the present disclosure is to provide a device for monitoring the pressure applied to a surface by a subject.

[0007] An object of the present disclosure is to provide a system for monitoring the pressure applied to a surface by a subject. [0008] An object of the present disclosure is to provide an assembly for monitoring the pressure applied to a surface by a subject.

[0009] An object of the present disclosure is to provide a method for monitoring the pressure applied to a surface by a subject.

SUMMARY [0010] In accordance with an aspect of the present disclosure, there is provided a device for monitoring the pressure applied to a surface by a subject, the device comprising: a pad for overlaying the surface and for receiving external pressure thereon from the subject against the surface, the pad comprising two layers of conductive material and a layer of a semiconductor material interposed therebetween, the pad providing for receiving an electrical current flow therethrough, wherein a given amount of external pressure applied on the pad against the surface by the subject causes a given decrease of electrical resistance of the pad to the current flow thereby increasing electrical conductance.

[0011] In accordance with an embodiment, the device further comprises a detector in operative communication with the pad for detecting the amount of electrical resistance of the padding. In accordance with an embodiment, the detector comprises an ohmmeter. In accordance with an embodiment, the detector is in operative communication with a controller and a user interface for communicating that a given amount of pressure is being applied to the pad by the subject against the surface. In accordance with an embodiment, the user interface provides for communicating an amount of pressure beneath a given predetermined pressure threshold.

[0012] In accordance with an embodiment, the device further comprising one or more pressure sensors positioned at one or more respective regions of the pad, wherein the one or more sensors provides for sensing pressure applied to the one or more respective regions of the pad. In accordance with an embodiment, the one or more sensors are in operative communication with a controller and a user interface for communicating if a pressure is being applied to a given one of the one or more regions of the pad.

[0013] In accordance with an embodiment, the pad comprises an electrical circuit connected to an electrical source for providing a an electrical current thereto. In accordance with an embodiment, the electrical circuit comprises tinsel wires.

[0014] In accordance with an embodiment, the controller comprises processor or a microprocessor. In accordance with an embodiment, controller is in operative communication with a remote controller.

[0015] In accordance with an embodiment, the pad is provided in the form of an article selected from the group consisting of a chair cover, a bed cover, a floor cover, bodywear attire and any combination thereof. [0016] In accordance with an embodiment, at least one of the two layers of conductive material comprises a non-woven textile material.

[0017] In accordance with an embodiment, the layer of a semiconductor material comprises a piezoresistive material.

[0018] In accordance with an embodiment, the layer of a semiconductor material comprises an electrical discharge (ESD) material.

[0019] In accordance with an embodiment, the pad further comprises an external membrane covering at least one of the two layers of conductive material. In accordance with an embodiment, the device further comprises an additional sheet of material interposed between the external membrane at least one of the two layers of conductive material.

[0020] In accordance with an aspect of the present disclosure, there is provided an assembly for monitoring the pressure applied to a surface by a subject, the device comprising: a pad for overlaying the surface and for receiving external pressure thereon from the subject against the surface, the pad comprising two layers of conductive material and a layer of a semiconductor material interposed therebetween, a power source for being in placed in operative communication with the padding for providing the pad with an electrical current flow therethrough; a detector for being placed in operative communication with the pad for detecting the electrical conductance and/or resistance thereof; a controller in for being placed in operative communication with the detector for receiving detecting the electrical conductance and/or resistance thereof; a user interface for being placed in operative communication with the controller; wherein a given amount of external pressure applied on the pad against the surface by the subject causes a given decrease of electrical resistance of the pad to the current flow thereby increasing electrical conductance, wherein a variation in the electrical resistance and/or electrical conductance of the pad is detected by the detector and communicated to the user interface via the controller.

[0021] In an embodiment, the assembly further comprises a pressure sensor assembly mounted to the pad for detecting pressure applied to regions of the pad, the pressure sensor assembly providing for being placed in operative communication with the controller to communicate the pressure being applied to regions of the pad to the user interface via the controller.

[0022] in accordance with an aspect of the present disclosure, there is provided a system for monitoring the pressure applied to a surface by a subject, the system comprising: a main controller; a plurality of devices for monitoring the pressure applied to a surface by a subject, each of the devices comprising: a pad for overlaying the surface and for receiving external pressure thereon from the subject against the surface, the pad comprising two layers of conductive material and a layer of a semiconductor material interposed therebetween, the pad providing for receiving an electrical current flow therethrough, wherein a given amount of external pressure applied on the pad against the surface by the subject causes a given decrease of electrical resistance of the pad to the current flow thereby increasing electrical conductance; a plurality of detectors, each detector being in operative communication with the pad for detecting the electrical conductance and/or resistance thereof; and a plurality of processors, each processor being in communication with the main controller and with one or more detectors for receiving information threrefrom related to the electrical conductance and/or resistance of the pad associated with each detector in communication therewith and for transmitting this information to the main controller,

[0023] In accordance with an aspect of the present disclosure, there is provided a system for monitoring the pressure applied to a surface by a subject, the system comprising: at least one device for monitoring the pressure applied to a surface by a subject, the device comprising: a pad for overlaying the surface and for receiving external pressure thereon from the subject against the surface, the pad comprising two layers of conductive material and a layer of a semiconductor material interposed therebetween, the pad providing for receiving an electrical current flow therethrough, wherein a given amount of external pressure applied on the pad against the surface by the subject causes a given decrease of electrical resistance of the pad to the current flow thereby increasing electrical conductance; at least one detector a for being in operative communication with the pad for detecting the electrical conductance and/or resistance thereof; a user interface, a controller in operative communication with the at least one detector and the user interface, the controller comprising a processor with an associated memory containing processor executable code that when execute provide the controller with performing computer implementable steps of: receiving the information from the detector relative to the to the conductance and/or resistance within the pad; associating a given level of conductance and/or resistance to a given level of pressure applied on the pad; determining whether the given level of pressure is authorized or unauthorized based on predetermined parameters contained with the memory; and communicating the determined authorized or unauthorized pressure via the user interface.

[0024] In an embodiment, the parameters are selected from the group consisting of a pressure threshold, a time of day, a pressure time interval and any combination thereof.

[0025] In an embodiment, the system further comprises a pressure sensor assembly mounted to the pad for detecting pressure applied to regions of the pad, wherein the controller is in operative communication with the sensor assembly to receive information therefrom relative to pressure being applied to regions of the pad, wherein when executing the processor executable code the controller is provided with performing computer implementable steps of: receiving information from the pressure sensor assembly regarding the regions of the pad on which pressure is being applied; determining a pressure pattern on the pad based on the regions of the pad on which pressure is being applied; determining whether the determined pressure pattern on the pad is authorized or unauthorized based on predetermined parameters contained with the memory; and communicating the determined authorized or unauthorized pressure via the user interface. In an embodiment, the parameters are selected from the group consisting of a pressure threshold which include the pressure level applied to the pad for a give pattern, the time of day, the pressure time interval and any combination thereof.

[0026] In accordance with an aspect of the present disclosure, there is provided a method for monitoring the pressure applied to a surface by a subject, the method comprising: overlying the surface with a pad; providing an electrical current flow to the pad; providing for the subject to exert an external pressure on the pad against the surface, wherein a given amount of external pressure applied on the pad against the surface by the subject causes a given decrease of electrical resistance of the pad to the current flow thereby increasing electrical conductance; detecting electrical resistance and/or electrical conductance of the pad; evaluating the pressure on the padding based electrical resistance and/or electrical conductance of the pad; communicating the evaluated pressure to a user.

[0027] The pressure of a subject on a pad of various configurations through which an electrical current flow Is provided causes a reduction in electrical resistance which increases electrical conductance. The variations of electrical resistance and/or electrical conductance are detected and communicated to a user monitoring the subject thus. The detected electrical resistance and/or electrical conductance is indicative of the type of pressure. The type of pressure on the pad is indicative of an authorized or unauthorized position of the subject.

[0028] Other objects, advantages and features of the present disclosure will become more apparent upon reading of the following non-restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings,

BRIEF DESCRIPTION OF THE DRAWINGS [0029] In the appended drawings: [0030] Figure 1 is a perspective first face view of the device for monitoring the pressure applied to a surface by a subject in accordance with a non-restrictive illustrative embodiment of the present disclosure; [0031] Figure 2 is a perspective second face view of the device of Figure 1;

[0032] Figure 3 is a perspective view of the disassembled device of Figure 1 , showing a first layer of the conductive material;

[0033] Figure 4 is a perspective view of the disassembled device of Figure 1 , showing the layer of semiconductor material mounted to the first layer of the conductive material of Figure 3;

[0034] Figure 5 is a perspective view of the disassembled device of Figure 1 , showing a second layer of conductive material mounted to the layer of semiconductor material of Figure 4 and the first layer of the conductive material of Figure 3;

[0035] Figure 6 is perspective view of the disassembled device of Figure 1 , showing the contour edge material on which external membrane covering the layers of conductive conductive material of Figures 3 and 5, respectively are mounted to;

[0036] Figure 7 is a perspective lateral view of an edge of the disassembled device of Figure 1 , showing electrical wires mounted to the first and second layers of conductive material of Figures 3 and 5;

[0037] Figure 8 is schematic representation of a device and/or assembly for monitoring the pressure applied to a surface by a subject in accordance with a nan- restrictive illustrative embodiment of the present disclosure; [0038] Figure 9 is a cross-sectional view of the pad of a device for monitoring the pressure applied to a surface by a subject in accordance with a non-restrictive illustrative embodiment of the present disclosure;

[0039] Figure 10 is a cross-sectional view of the pad of a device for monitoring the pressure applied to a surface by a subject in accordance with another non-restrictive illustrative embodiment of the present disclosure; and

[0040] Figure 11 is a schematic representation of the system for monitoring the pressure applied to a surface by a subject in accordance with a non-restrictive illustrative embodiment of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS [0041] Generally stated and in accordance with an aspect of the present disclosure, there is provided a device for monitoring the pressure applied to a surface by a subject, the device comprising a pad for overlaying the surface and for receiving external pressure thereon from the subject against the surface. The pad comprising two layers of conductive material and a layer of a semiconductor material interposed therebetween, The pad provides for receiving an electrical current flow therethrough. A given amount of external pressure applied on the pad against the surface by the subject causes a given decrease of electrical resistance of the pad to the current flow thereby increasing electrical conductance.

[0042] Figures 1 and 2 show a device 10 for monitoring the pressure applied to a surface by a subject in accordance with a non-restrictive illustrative embodiment of the present disclosure. [0043] The device 10 comprises a pad 12 having first and second faces 14 and 16, respectively and defining a peripheral edge 18 thereof. A pocket 20 extends from the peripheral edge 18. The pad 12 is shown in the form of a rectangular pad, yet the pad 12 can be provided in other geometric configurations. The pad 12 is used as a seat to overlie on a surface such as a bed or a chair for example. Of course, the pad 12 can also be a bed sheet for overlying almost the full bed sized. Alternatively, the pad 12 can be provided in the form or a floor covering for overlying a given portion of the floor. The pad 12 can also be provided in the form of a bodywear attire, for the legs, arms, trunk of the body in order to monitor the pressure applied on a surface of a chair, bed, bench and the like when the subject wearing the attire is occupying such a surface.

[0044] The pad 12 of the present non-limiting example, is shown defining top and bottom edges 22A and 22B and opposite later lateral edges 24A and 24B which together form the peripheral edge 18. In this example, the pocket 20 extends from the top edge 22A.

[0045] Turning now to Figures 3 to 5, the pad 12 comprising two layers of conductive material 26A and 26B with a third layer 28 of a semiconductor material interposed between layers 26A and 26B, In an embodiment, the conductive material 26A and/or 26B comprises a sheet of non-woven conductive textile material in an embodiment, the layer of semiconductor material 28 comprises a sheet of piezoresistive material. In an embodiment, the layer of semiconductor material 28 comprises a sheet of electrical discharge (BSD) material.

[0046] A respective sheet of material 30A and 30B covers each layer of conductive material 26A and 26B, respectively. As shown in Figure 2, sheet 30B includes printed instructions 31. Sheets 30A and 30B are made of insulating material, polyurethane, textile and other suitable materials and any combination thereof.

[0047] As shown in Figure 6, the device comprises oversized contour material 32 which sandwiches the edges of the sheets 30A, 30B and 28. External membrane sheets 34A and 34B are heat sealed on the contour material 32 encapsulating sheets 30A, 30B, 26A, 26B and 28 therebetween. The membrane sheets 34A and 34B can comprise polyurethane for example.

[0048] Figure 7 shows wires 36A and 36B that are stitched into respective conductive layers 26A and 26B. The wires 36A and 36B are in communication with an electrical source 38 (see Figure 8) such as a transistor for example that provides an electrical current to the layers 26A and 26B and thus to the padding 12. In an embodiment, electrical circuits are stitched into layers 26A and 26B and are in wire or wireless communication with an electrical source (such as power source 38 shown in Figure 8) for providing the electrical current.

[0049] The pad 12 overlays a surface such as a chair for example. When a subject such as a care facility resident, a patient, and the like, sits on the chair, the weight of the subject imparts an external pressure on the padding 12 against the surface of the seat of the chair. [0050] This pressure provides mechanical stress to the semiconductor material 28 and results in decreasing the electrical resistance of the pad 12 thereby increasing the flow of the electrical current. Thus, the amount of external pressure (i.e. mechanical stress) exerted on the semiconductor material 28 is inversely proportional to the electrical resistance of the semiconductor material 28 which is inversely proportional to the electrical conductance of the semiconductor material 28. In effect, the amount of external pressure (i.e. mechanical stress) exerted on the pad 12 is thus inversely proportional to the electrical resistance of the pad 12 which is thus inversely proportional to the electrical conductance of the pad 12. The greater the pressure on the pad 12, the greater the electrical conductance of the pad 12, the lesser the pressure on the pad 12, the lesser the electrical conductance of the pad 12. The variations in electrical conductance of the pad 12 are directly proportional to variation of the pressure thereon. [0051] As shown in Figure 8, a detector 40 is in communication with the pad

12 to detect electrical conductance and/or electrical resistance. In an embodiment, the detector 40 is in communication with a user interface 42 for communicating this information to a user via a controller 44 in order to indicate the detected electrical conductance and/or the detected electrical resistance and/or the presence or absence of pressure on the pad 12 and/or the degree of pressure and/or whether the present or absence and/or the degree (or level) of pressure on the pad 12 is within an acceptable or authorized level.

[0052] In an embodiment, the user interface 42 and the controller are provided in a single unit 45. In an embodiment, unit 45 is a handheld mobile unit. In an embodiment, the interface 42 is a handheld mobile unit with an integrated processor in operative and wireless communication with the controller 44.

[0053] Figure 8 also shows that a power source 38 provides electrical current to the pad 12. In an embodiment, the power source 38 and the detector 40 may be provided in a single power source and detection unit 39. In an embodiment, the detector 40 comprises an electrical resistance measurement tool that sends an electrical current via wires 36A and 36B through the conductive layers 26A and 26B to measure electrical resistance. In an embodiment, the electrical resistance measurement tool is an ohmmeter. In an embodiment, the power source 38 is a battery providing the detector 40 with electrical power. In an embodiment, the unit

39 is positioned within the pocket 20 of the pad 12. In an embodiment, the detector

40 and the power source 38 are separate units and are positioned within the pad 12 including within the pocket 20. In an embodiment, the wires 36A and 36B extend outwardly of the pad and the detector 40 is positioned outside the pad 12 along with the power source 38 which can be provided as separate pieces or in a single unit 39.

[0054] In an embodiment, the detector 40 is in operative communication with the controller 44 via a wire connection. In an embodiment, the detector 40 is in wireless operative communication with the controller 44, via a wireless transmitter 35 connected to the detector 40 for transmitting a signal to the wireless receiver 37 connected to the controller 44.

[0055] Figure 8 shows that the pad 12 is comprises a pressure sensor assembly 41 including a plurality of pressure sensors embedded in different regions of the pad 12. Thus, the pressure sensor assembly 41 detects the areas or regions of the pad 12 where pressure is being detected. As such, given pressure patterns, positions on the pad 12 and/or amounts of pressure may be considered authorized or unauthorized. In an embodiment, the pressure sensor assembly 41 is in operative communication with the power source 38 and/or another power source 38' which can be positioned within pad 12 or positioned externally to pad 12. The pressure sensor assembly 41 is in operative communication with the controller 44. This communication may be wireless or wired communication. Accordingly, the pressure sensor assembly 41 provides for the controller 44 to indicate regions of the pad 12 on which pressure is being applied via the interface 44.

[0056] In an embodiment, the units 39 and 45 are provided in a single integrated unit 47.

[0057] Turning now to Figure 9, there is shown a cross section of a device 10' for monitoring the pressure applied to a surface by a subject in accordance with a non-restrictive illustrative embodiment of the present disclosure showing the various layers (or sheets) of the pad 12' in accordance with a non-limiting illustrative embodiment of the present disclosure. Devices 10 and 10' are similarly configured.

[0058] The pad 12' includes outer layers 30A' and 30B' each covering conductive layers 26A' and 26B' respectively. In an embodiment, layers 30A' and 30B' comprise insulating polyurethane material. Each conductive layer 26A' and 20B' contains a wire 36A' and 36B' embedded therein for providing electric flow. In an embodiment, wires 36A' and 36B' comprise tinsel wires. In an embodiment, wires 36A' and 36B' are leather covered, The wires 36A' and 36B' are connected to the power source 38 and the detector 40 as explained above for device 10. The semiconductor layer 28' is positioned between layers 26A' and 26B' In an embodiment layer 28' is a piezoresistive sheet.

[0058] Turning to Figure 10, there is shown a device 10" comprising a pad 12" having outer layers 30A" and 30B", respectively covering layers 60A" and 60B" which respectively overlie conductive layers 26A" and 26B" having respective wires 36 A" and 36B" embedded therein and sandwiching the semiconductor layer 28" therebetween. Device 10" comprises a pressure sensor assembly 41 (as discussed above for device 10) comprising a plurality of sensors 62" positioned in specific areas or regions 64" of the pad 12”. In an embodiment, layers 60A” and 60B” provide the separate regions, 64", each region includes one or more sensor 62". When pressure is applied to a certain region 64", this is sensed by the sensor 62" contained within this region 62", thus the areas or regions 64" of pad 12" on which pressure is being applied is transmitted to a processor (such as processor 40) as explained above,

[0060] In an embodiment, the power source 38 provides an electrical charge via a transmitter to the conductive material directly and not via the wires provided herein.

[0061] In an embodiment, if the electrical conductivity of the pad 12 is detected to fall beneath a certain threshold this is indicative that an insufficient amount of pressure is being applied on the pad 12. For example, the user may not be sitting on the chair on which the pad 12 is placed, or may be on the floor with their arms on the seat or the chair (the area that the pad 12 overlies) trying to get up thus a pressure is being applied but an insufficient amount of pressure when compared to the full weight of the user when seated on the chair and thus on the pad 12. [0062] Of course, the detector 40 is configurable to detect either the presence or absence of pressure (on/off detector) on the pad 12 or variations (e.g. an ohmmeter) of the pressure based on predetermined conductivity thresholds.

[0063] In an embodiment, the controller 44 is a processor with an associated memory containing processor executable code that when execute provide the controller for executing computer implementable steps of: receiving the information from the detector 40 relative to the to the conductance and/or resistance within the pad 12; associating a given level of conductance and/or resistance to a given level of pressure applied on the pad 12; determining whether the given level of pressure is authorized or unauthorized based on predetermined parameters contained with the memory relative to the pressure thresholds. Other parameters for determining whether a pressure threshold is authorized or unauthorized is the time of day of the pressure threshold and/or the time interval of that pressure threshold, [0064] The controller 44 is also provided to execute the computer implementable steps of: receiving information from the pressure sensor assembly regarding the regions of the pad on which pressure is being applied thereby determining a pressure pattern on the pad; determining whether the determined pressure pattern on the pad 12 Is authorized or unauthorized based on predetermined parameters which include the pressure level applied to the pad 12 for a give pattern. Other parameters for determining whether a pressure pattern is authorized or unauthorized is the time of day of the pressure pattern and/or the time interval of that pressure pattern.

[0065] The user may configure the parameters of determining whether or not pressure thresholds along with pressure patterns are authorized or unauthorized based on other criteria that can be added to the memory.

[0066] The controller 44 is provided with executing the computer implementable step of determining a pressure condition. A pressure condition comprising a pressure threshold being exerted on the pad 12. A pressure condition further comprises the pressure threshold in combination with the other parameters. A pressure condition further comprises the pressure threshold in combination with the pressure pattern with or without the other parameters. The controller 44 is provided with executing the computer implementable step of assigning a condition score to the pressure condition based on a predetermined scoring system in the memory.

[0067] The processor 44 thus signals the user via the user interface 42 whether the pressure information received is authorized or unauthorized or provides the user with a condition score. The condition score can be indicative of a more or less authorized or unauthorized pressure scenarios which may require the user to evaluate other available indicators before acting.

[0068] In an embodiment, the processor 44 comprises a processor or a microprocessor or any combination thereof.

[0069] In an embodiment, the user interface 42 receives pressure condition information from a plurality of devices 10. In an embodiment, the processor 44 receives information from a plurality of detectors 40, each detector being associated with a respective pad 12. In an embodiment, the processor 44 receives information from a plurality of pressure sensor assemblies 41 , each assembly being associated with a respective pad 12. [0070] The pocket 20 may contain the power source 38, the detector 40 and the microprocessor 44.

[0071] In an embodiment, the user interface 42 may be provided by a handheld device.

[0072] Figure 1 1 shows a system 50 for monitoring pressure applied to a surface by a subject. The system includes a remote main controller 52 in communication with a plurality of processors 44, each processor 44 associated with one or a plurality of detectors 40, (and optionally one or a plurality of pressure sensor assemblies 41) each detector 40 and each detector assembly 41 being associated with one pad 12. The detector 40 and pad 12 forming a device 10, In an embodiment, one processor 44 associated with one detector 40 and one pad 12 forms one device 10. In an embodiment, the one processor 44 is associated with a user interface 42. In an embodiment, the processor 44 and user interface 42 form a single unit. In an embodiment, the processor 44 and the user interface are separate. In an embodiment, a user interface 42 Is associated with more than one processor 44. The main controller 52 receives information from the processor 44 regarding the pressure condition on the one or more pads12 including response time and other associated conditions and events for further evaluation, comparison, data tracking and reports. A device 10 as described hereinabove may optionally also contain a detector assembly 41 as previously explained.

[0073] It is understood that wireless communication herein can be provided by radiofrequency communication, network communication or other types of wireless communication as can be appreciated by those having skill in the art.

[0074] The various features described herein can be combined In a variety of ways within the context of the present disclosure so as to provide still other embodiments, As such, the embodiments are not mutually exclusive. Moreover, the embodiments discussed herein need not include all of the features and elements Illustrated and/or described and thus partial combinations of features can also be contemplated. Furthermore, embodiments with less features than those described can also be contemplated. It is to be understood that the present disclosure is not limited in its application to the details of construction and parts illustrated in the accompanying drawings and described hereinabove. The disclosure is capable of other embodiments and of being practiced in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation. Hence, although the present disclosure has been provided hereinabove by way of non-restrictlve illustrative embodiments thereof, it can be modified, without departing from the scope, spirit and nature thereof and of the appended claims.