Note: Descriptions are shown in the official language in which they were submitted.
SMART VENT APPARATUS AND SYSTEM FIELD OF THE INVENTION [0001] At least one embodiment of the present invention pertains to smart vents or registers, and more particularly, to a wirelessly connected motorized vent or register in communication with a gateway so as to act as a virtual thermostat. BACKGROUND [0002] A vast majority of homes and offices in the U.S. and other countries use a "forced air" system for heating and cooling the interior of the building. In many of these systems, especially in residential settings, there is normally just one thermostat in one location, one central blower, ducts to distribute air to the different rooms, and vents in each room for the air to flow through. This thermostat provides only one central point for temperature control for the whole building. [0003] If the door to a room is partially or completely closed, or if the room is remote from the thermostat, the temperature in the room can differ significantly compared to the temperature measured by the thermostat. It can get either too hot or too cold depending on variables like the size of the room, the size of the house, the location or orientation of the room, the time of the year, the construction of the HVAC system, etc. [0004] Also, there is no way for the occupants to set different temperatures for each room. For instance, parents might want to keep their children's bedrooms warmer than the master bedroom when the HVAC system is being used to heat the 1 CA 2995097 2018-02-14 house. Conversely, the children's rooms might need to be cooler than other rooms when the HVAC system is being used to cool the house. Or some rooms may not need to be heated or cooled at all when vacant, either temporarily or permanently. [0005] Accordingly, the lack of individual control for each room makes a conventional HVAC and thermostat system very inefficient in terms of both individual comfort and energy savings. [0006] To enable individual temperature control for multiple rooms, smart vent systems have been developed that allow control airflow from an HVAC system to be controlled for individual vents located in different rooms. The smart vents can open or close independently in response to local temperature changes. In addition, a vent's open or closed state can be influenced by control signals issued from a central controller, usually in the form of a smart thermostat, in order to regulate the air flow and therefore the temperature of the individual rooms where the smart vents are located. However, such systems' reliance on a smart thermostat or other central controller presents limitations in effectively regulating the temperature of individual rooms. The use of a thermostat at a single central location prevents the system from detecting the conditions of individual rooms and regulating the HVAC and airflow to those rooms accordingly. In addition, by using a single central controller to provide all control signals to the vents, any limitations of the central controller, such as limited input or output communications, will limit the responsiveness or other capabilities of the system. 2 CA 2995097 2018-02-14 SUMMARY [0007] This summary is provided to introduce in a simplified form certain concepts that are further described in the Detailed Description below and the drawings. This summary is not intended to identify essential features of the claimed subject matter or to limit the scope of the claimed subject matter. [0008] In a first aspect, a smart vent system comprising one or more smart vents is disclosed. The smart vent comprises a motorized vent, a temperature sensor, a gateway link and a controller. The motorized vent is configured to modulate between an open position and a closed position. The temperature sensor is configured to sense the temperature in the smart vent environment and generate temperature data based on the sensed temperature. The gateway link is configured to communicate with a gateway. The controller is configured to generate HVAC system control information based on the temperature data, control the modulation of the motorized vent, and send the HVAC system control information to the gateway via the gateway link. [0009] In a second aspect, a smart vent system is disclosed comprising a motorized vent device and a thermostat device. The motorized vent device comprises a motorized vent configured to modulate between an open position and a closed position in response to received vent control information. The thermostat device comprises a temperature sensor, a gateway link, and a short-range link. The temperature sensor is configured to sense the temperature in the thermostat device environment and generate temperature data based on the sensed temperature. The gateway link is configured to communicate with a gateway. The short-range link is used for communicating with the motorized vent device. The controller is configured 3 CA 2995097 2018-02-14 to generate HVAC system control information based on the temperature data, generate vent control information based at least in part on the temperature data, send the vent control information to the motorized vent device via the short range link, and send the HVAC system control information to the gateway via the gateway link. [0010] In a further aspect, a gateway is disclosed. The gateway manages a smart vent system. The gateway comprises a smart vent link for receiving HVAC system control information from one or more smart vents. The gateway in some embodiments can also communicate with services hosted by remote computational entities. [0011] Other aspects of the technique will be apparent from the accompanying figures and detailed description. Further example embodiments of the claimed subject matter will be appreciated from the following detailed description and drawings. 4 CA 2995097 2018-02-14 BRIEF DESCRIPTION OF THE DRAWINGS [0012] One or more embodiments of the present invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements. [0013] Figure 1 is a block diagram of a smart system that uses a smart thermostat. [0014] Figure 2 is a block diagram illustrating a smart vent system, including a gateway communicating directly with the HVAC system, thereby eliminating the need for a smart thermostat. [0015] Figure 3 is a block diagram of a memory of an example smart vent showing the structure of the software blocks stored in the memory. [0016] Figure 4 is a block diagram of an example gateway. [0017] Figure 5 is a block diagram of the smart vent of Figure 2 wherein the smart vent is composed of a single device. [0018] Figure 6 is the block diagram of a smart vent system wherein the smart vent system is divided into two separate pieces, one being a motorized vent device and the other being a thermostat device with other sensors integrated within. CA 2995097 2018-02-14 DETAILED DESCRIPTION [0019] The making and using of the presently described embodiments are discussed in detail below. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. [0020] References in this description to "an embodiment", "one embodiment", or the like, mean that the particular feature, function, structure or characteristic being described is included in at least one embodiment of the present invention. Occurrences of such phrases in this specification do not necessarily all refer to the same embodiment. On the other hand, such references are not necessarily mutually exclusive either. [0021] Disclosed herein are smart vent devices and systems that regulate the state of one or more smart vents based at least in part on sensor data collected by sensors included in the smart vent itself. A smart vent may have a motor or other mechanical actuator to open or close the vent in response to received communications or internal control signals. A smart vent equipped with a temperature sensor and/or other room condition sensors (e.g. air quality, air pressure, humidity, light, motion) may supplement or replace the central temperature sensing functionality of a smart thermostat. The use of a smart vent with sensors, as described herein, may therefore eliminate the need for a smart thermostat as part of a smart climate control system for a building. The described smart vents with sensors may also enable feedback-regulated climate control for individual rooms or other locations within a building by providing room- specific temperature sensor data and/or other sensor data. 6 CA 2995097 2018-02-14 [0022] In some embodiments, the smart vent is equipped with a user device link for communicating with a user device. The user device is operated by a user and may be a mobile electronic device (such as a smartphone), a laptop or desktop computer, or another electronic device (such as a remote control unit). The user device link may be a wired or wireless communication link, such as a BluetoothTM Low Energy (BLE) link. In some embodiments, the user device link allows for direct communication between the user device and the smart vent without going through any intermediary devices or networks. Some of these embodiments make use of a user device link that is configured to wake the smart vent from a low-power or sleep mode in response to communications from the user device. [0023] In some embodiments, the smart vent is further provided with a gateway link for communicating with a gateway. The gateway link may in some embodiments be a long-range wireless link such as a low-power low-frequency (LPLF) radio link. The gateway may in some embodiments be an electronic device in communication with one or more smart vents over those smart vents' gateway links. In some embodiments, the gateway is configured to directly control an HVAC system for the building. In other embodiments, the gateway is configured to control the HVAC system indirectly through one or more other devices. The gateway may respond to communications from one or more of the smart vents to set the operating mode or parameters of the HVAC system (e.g. power level of heating, power level of cooling, humidity settings, off). The gateway may further communicate with the smart vent systems to provide instructions for opening or closing one or more of the smart vents. In some embodiments, the smart vents spend the majority of their time in a low-power or sleep mode, and communications 7 CA 2995097 2018-02-14 with the gateway only take place periodically during a wake-up period. This may make the smart vents less immediately responsive to the gateway than they are to the user device. [0024] Thus, in some embodiments the smart vent comprises two radios: one being a low power, but short range, Bluetooth (BLE) radio and other being a low power, lower frequency (LPLF) radio but with a longer range enabling it to have a wider area of coverage. The smart vent communicates via BLE with a smart phone or similar user device for short range communication and connects with a gateway, which can be a further distance away, via the LPLF radio. The smart vent receives a wireless command from the gateway or the smart phone to open a vent so that air flows from the duct to the room. A controller, such as a processor coupled to a memory, opens the motorized vent by sending a command to a motor or a motor controller to open the vent. A motor, coupled to the storage and processor, opens the vent upon receiving the command, thereby regulating the airflow into the room. [0025] In some embodiments, a program server is provided to coordinate the operation of the smart vents and HVAC system using program data. The program data may include schedule data for changing HVAC and vent operating parameters at different times of day, different days of the week, or other time periods (such as during a week when the building is scheduled to be empty). It may also include operating parameters for the vents in particular rooms or areas of the building, such as instructions for maintaining a specific temperature in a specific room or for keeping a smart vent in a vacant room closed. The program server may be a server or set of servers on the Internet or another network in communication with the gateway. In other embodiments, the program server may be an electronic device in 8 CA 2995097 2018-02-14 communication with the gateway through a communication link rather than over a network. In still other embodiments, the program server may be a software or hardware module included as part of the same device as the gateway. [0026] The smart vent(s), gateway, and program server may be used in various combinations in different embodiments, as described in detail herein. In some embodiments, a smart vent system is provided to properly manage and control the temperatures in individual rooms. The system may be employed to provide command and status information to an HVAC control device that controls the HVAC system and turns it on or off. [0027] In some embodiments, this HVAC control device may be a smart thermostat. The smart thermostat may be connected to a server in the cloud or on another network, through an Internet connection or other network connection. The smart thermostat may also be connected to the HVAC system through a wired link and/or a wireless link. The functionality of the smart thermostat may be accessed using a software Application Program Interface (API). The smart vent system can use the API to communicate with the smart thermostat over a wired or wireless communication link. [0028] In other embodiments, a smart vent system can eliminate the need for a smart thermostat by directly communicating with a gateway that can control the HVAC system (e.g., turn it on and off). In such embodiments, the temperature sensing and regulating functionality of the smart thermostat is replaced by one or more smart vents with temperature sensors. Optionally, one of the smart vents may be located where the smart thermostat would normally be placed to control the temperature at that location. Such an embodiment of a smart vent system provides 9 CA 2995097 2018-02-14 two potential advantages over a smart thermostat system using conventional vents: first, it allows monitoring of the temperature or other climate conditions in individual rooms via the sensing capabilities of the smart vents. Second, even if a smart thermostat system were equipped with multiple remote temperature sensors to provide temperature data on individual rooms, it would still not be able to control the central airflow in a manner so as to provide room-specific temperature control, as it would not be able to control the airflow in each room; doing so requires individually controllable smart vents in each room. [0029] Example embodiments will now be described in detail with reference to the drawings. Figure 1 is a block diagram illustrating a smart vent system 100 including at least one smart vent 120 working with a smart thermostat 170 to control an HVAC system 180. The smart vent 120 is located within a room and communicates with a gateway 140 via a gateway link, such as wireless LPLF radio link 215. The smart vent 120 may send HVAC system control information 104 to the gateway 140 over the LPLF radio link 215, such as instructions to turn the HVAC system 180 on or off, to switch between heating and cooling, to modulate the power or speed of the blower, and/or to regulate a humidifier or dehumidifier. The LPLF radio link 215 may also be used by the smart vent 120 to receive vent control information 102 from the gateway 140, such as instructions to open or close the vent or to partially open the vent a specific amount (i.e. to modulate the vent between an open position and a closed position). [0030] The gateway 140 communicates with a program server 150 via a program server link. This link may in various embodiments be a wired connection, such as Ethernet connection 122, or a wireless connection, such as Wi-Fi (802.11) CA 2995097 2018-02-14 connection 124. The program server 150 may in some embodiments be a cloud server in communication with the gateway 140 over the Internet via the Ethernet connection 122 or the Wi-Fi connection 124. The gateway 140 may use the Ethernet connection 122 or the Wi-Fi connection 124 to send information to the program server 150, such as sensor information from one or more smart vent 120 sensors or HVAC control information 104 to control the HVAC system 180. The gateway 140 may also receive information over the Ethernet connection 122 or the Wi-Fi connection 124 from the program server 150, such as vent control information 102 to control the state of one or more smart vents 120 based on the program data 106 of the program server 150. For example, the program server 150 may send vent control information 102 to the gateway 140 at a specific time of day to cause a smart vent 120 in a specific room to close, thereby minimizing the application of heating or cooling in a room that is scheduled to be unoccupied at that time of day. The vent control information 102 may be included as part of program data 106 sent from the program server 150 to the gateway 140. [0031] The program server 150 communicates with the smart thermostat 170 through a smart thermostat server 160 using an API defined by the smart thermostat server 160. The smart thermostat server 160 may in some embodiments be a cloud server in communication with the program server 150 over the Internet. The smart vent 120 can direct the smart thermostat 170, via the gateway 140, program server 150, and smart thermostat server 160, to turn the HVAC system 180 on or off depending on whether the desired room temperature is achieved for all rooms equipped by smart vents. 11 CA 2995097 2018-02-14 [0032] The smart vent 120 can also communicate with a user device, such as smart phone 130, directly via a user device link. The user device link may be a radio link such as the BLE link 210 shown in Figure 1. The user device may send vent control information 102 to the smart vent 120 via the BLE link 210 in some embodiments. [0033] Figure 2 shows a second embodiment where the smart thermostat is eliminated altogether. In this smart vent system 200, a gateway 140 communicates directly with the HVAC system 180. This system 200 therefore eliminates the need for a smart thermostat 170 or its associated server 160. [0034] In operation, this smart vent system 200 can maintain different temperatures for each smart-vent-equipped room. Smart vents 120 can be placed in multiple rooms or locations and each can send sensed temperature data from each room wirelessly over the gateway link (LPLF radio link 215) to a gateway 140 which connects to the HVAC system 180 directly. Once the gateway 140 detects that all smart-vent-equipped rooms have reached their desired temperature (according to program data 106 for desired temperatures for each room), it will shut off the blower of the HVAC system 180 and wait for a smart vent 120 to report a sufficient change in temperature to turn on the HVAC system again (i.e., a decrease in sensed temperature can reactivate the heating system, or conversely an increase in sensed temperature can reactivate the air conditioner). [0035] In some embodiments, the gateway may be set to a first configuration to operate as shown in Figure 1, and may be set to a second configuration to operate as shown in Figure 2. 12 CA 2995097 2018-02-14 [0036] The operation of the smart vent 120 is controlled by a controller, such as a specialized hardware circuit or a processor coupled to a memory containing software instructions. Figure 3 is block diagram illustrating the memory 300 of an example smart vent 120 and specifically the software 310 stored in the memory 300. The software 310 includes a thermostat engine 320 for using the temperature sensor to generate temperature data, a motor engine 330 for controlling the motorized vent, a BLE engine 340 for communicating over the BLE link 210, an LPLF radio engine 350 for communicating over the LPLF link 215, and a complementary sensors engine 360 for controlling, or generating or receiving sensor data from, other sensors included in the smart vent 120. [0037] The thermostat engine 310 receives commands via the BLE link 210 (using the BLE engine 340) or LPLF radio link 215 (using the LPLF radio engine 350) to open or close the vent using the motor engine 330. [0038] Figure 4 shows a block diagram of an example gateway 140. A controller 430, such as a microprocessor, controls and receives inputs from a number of other subsystems. A smart vent link, such as an LPLF radio link 215, communicates with the smart vents 120. The gateway 140 has a gateway user device link, such as gateway BLE radio link 212, which communicates with a user device such as a smart phone 130. The user device may communicate with the gateway 140 in some embodiments for the purpose of configuration, testing, and/or monitoring. A Wi-Fi radio link 410 and Ethernet connection circuit 420 connect the gateway 140 to the program server 150 via the Internet. The HVAC interface 440 connects the gateway 140 to the HVAC system 180 to control turning the HVAC system 180 on and off and/or controlling subsystems such as the blower speed. 13 CA 2995097 2018-02-14 Gateway sensors 435 can be a combination of different sensors for monitoring environmental conditions such as air quality, temperature, pressure, and humidity within or in the vicinity of the HVAC system 180 and generating gateway sensor data based on the sensed conditions. Power management circuits 450 receive electric power from the AC power circuits 470 to operate the gateway, to charge the backup battery 460, and to use the backup battery 460 to power the gateway 140 when AC power is not available. [0039] Figure 5 shows a block diagram of an example self-contained smart vent 500. It consists of a controller 550 used to control and communicate with a motorized vent 510 and a number of additional sensors 520, including a temperature sensor 530 which is used to measure the room temperature. The additional sensors 520 may also include, in various embodiments, a humidity sensor, a pressure sensor, a light sensor, an air quality sensor, a motion sensor, a presence sensor, an air pressure monitor, an air quality monitor, a CO2 monitor, a carbon monoxide monitor, a smoke monitor, a microphone, an optical sensor, or any other sensor useful for monitoring the environment or the state of the smart vent 120. In this embodiment, the self-contained vent 120 communicates with the gateway 140 and a user device (such as smart phone 130) as shown in Figure 2 using the LPLP radio link 215 and the BLE link 210 respectively. In this embodiment, the controller 550 is a processor coupled to a memory 300 and manages the operation of the various subsystems based on instructions stored in the memory 300. [0040] Figure 6 shows a block diagram of a two-part smart vent 600 which is divided into two devices. One is a motorized vent device 620 which includes a 14 CA 2995097 2018-02-14 motorized vent 621 and optionally one or more motorized vent device sensors 622, such as a pressure sensor and a humidity sensor. The other is a thermostat device 630 with a temperature sensor 530 to measure the room temperature plus optionally one or more other thermostat device sensors such as sensors for humidity, pressure, light, air quality, presence, etc. Motorized vent device 620 and thermostat device 630 communicate with each other via a short range link such as a short range radio link 640 (e.g. a BLE radio link), and the thermostat device 630 communicates with the gateway 140 through another longer range radio link (such as an LPLF radio link 215). The motorized vent device 620 may send motorized vent device sensor data 108 to the thermostat device 630 over the short range link 640 for the thermostat device 630 to relay to the gateway 140 or to use in its own operations. The thermostat device 630 may send vent control information 102 to the motorized vent device 620 to control the motorized vent 621 based at least in part on temperature data generated by the temperature sensor 530. This two- part smart vent system allows a user to manually control the temperature of the room by manually manipulating thermostat device 630, without having to use a smart phone 130. [0041] The program data 106 may include different information in different embodiments. It may include schedule information identifying desired temperature levels and/or humidity levels for individual rooms or other locations at different times (e.g. times of day, days of the week, multi-day periods, etc.). It may include system operating parameters such as desired HVAC power consumption under different conditions (such as peak or off-peak hours of the day), desired HVAC blower speeds under different conditions, or overall desired temperature or CA 2995097 2018-02-14 humidity. It may also include data intended for system management, such as diagnostic information for testing the gateway, smart vents, and/or their various sub-systems. [0042] Vent control information 102 may include information instructing the motorized vent 510 to completely open, completely close, or modulate its position to a set point between a fully open and a fully closed position. In some embodiments it may include a desired temperature and/or humidity level for the location of the smart vent 120. The smart vent 120 can then act as a thermostat for that location by controlling the motorized vent 510 to modulate between an open and a closed position to maintain the desired temperature and/or humidity level. In order to maintain the desired temperature and/or humidity level, the smart vent 120 may also generate HVAC system control information 104 and send it to the gateway 140 in addition to modulating the position of the motorized vent 510. [0043] The HVAC system control information 104 may in some embodiments include a blower speed setting and a heating mode /cooling mode setting for the HVAC system 180. It may include instructions to activate or deactivate the HVAC system 180. It may include humidifier and/or dehumidifier settings for HVAC system 180 equipped with humidifiers or dehumidifiers. The format and/or content of the HVAC system control information 104 sent from a smart vent 120 to the gateway 140 may be the same or different from that of the HVAC system control information 104 sent from the gateway 140 to the program server 150. In some embodiments, the gateway or the smart vents 120 may generate HVAC system control information 104 based on the output of more than one smart vent 120: for example, the blower speed of the HVAC system may be set to a level sufficient to 16 CA 2995097 2018-02-14 effect a desired amount of heating or cooling of all the locations where smart vents are located by combining the blower speed settings of the HVAC system control information 104 from multiple smart vents 120. The HVAC system control information 104 may also include sensor data relevant to HVAC system operation, which may in some embodiments be used by the program server 150 to modify its schedule or program data 106. For example, the HVAC system control information 104 may include presence information for a location or for the building as a whole (as collected from, e.g., a presence sensor, a motion sensor, or a user device), which the program server 150 may use to modify its schedule or to generate new program information 106. [0044] The user device, such as the smart phone 130, may be used to directly communicate with the smart vent 120 over the user device link (such as BLE link 210) or with the gateway 140 over the gateway user device link (such as BLE link 212). The user device may thus provide vent control information 102 to the smart vent 120 directly or via the gateway 140. The user device may also be used to control other functions of the smart vent 120, gateway 140, HVAC system 180, or program server 150 by passing control instructions to the smart vent 120 or gateway 140 and having those instructions relayed to the device being controlled. The user device may also be used to display or otherwise communicate to the user information provided by the various components of the smart vent system (100 or 200). For example, the user device could be used to display the temperature in a room by receiving this information from the smart vent 120 in that room. The temperature sensor 530 of the smart vent 120 would collect or generate this information and it would be communicated to the user device via the user device 17 CA 2995097 2018-02-14 link (such as BLE link 210). The user device may also serve as a source of presence data for the system: when the BLE link 210 of a smart vent 120 detects the nearby presence of the user device in communication range, it could incorporate this presence information into its own operational logic (e.g. opening the motorized vent 510 to heat or cool the room where the presence is detected) and/or into its communications with the rest of the system (such as including the presence information in the HVAC system control information 104 sent to the gateway 140). [0045] Data collected from the smart vent sensors 520 and gateway sensors 435, such as the temperature sensor 530 and additional sensors 622, 632, may be used by the various components of the system in their operation. It may be taken into account by the program server 150 to modify its schedule and/or to generate program data 106. It may be used by the gateway 140, the program server 150, the smart thermostat server 160, and/or the smart thermostat 170 to control the operation of the HVAC system 180. It may be displayed or otherwise communicated to a user, such as via the user device or via a user interface included in the gateway 140 or smart thermostat 170. It may also be used by the smart vents 120 to change their operating parameters, such as the modulation of the position of the motorized vent 510 or the smart vents' power consumption mode settings. [0046] Each of the various engines 320, 330, 340, 350, 360 shown in Figure 3, while shown as software, can be alternatively implemented in pure hardware in some embodiments (e.g., specially-designed dedicated circuitry such as one or more application-specific integrated circuits (ASICs)), or in programmable circuitry appropriately programmed with software and/or firmware, or in a combination of pure hardware and programmable circuitry. 18 CA 2995097 2018-02-14 [0047] Similarly, the techniques described above can be implemented by programmable circuitry programmed and/or configured by software and/or firmware, or entirely by special-purpose circuitry, or by a combination of such forms. Such special-purpose circuitry (if any) can be in the form of, for example, one or more application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), etc. [0048] Software or embedded firmware to implement the techniques described herein may be stored on a machine-readable storage medium and may be executed by one or more general-purpose or special-purpose programmable microprocessors. A "machine-readable medium", as the term is used herein, includes any mechanism that can store information in a form accessible by a machine (a machine may be, for example, a computer, network device, cellular phone, personal digital assistant (PDA), manufacturing tool, any device with one or more processors, etc.). For example, a machine-accessible medium includes recordable or non-recordable media (e.g., read-only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media, flash memory devices, other nonvolatile storage mediums, etc.). [0049] The term "logic", as used herein, means: a) special-purpose hardwired circuitry, such as one or more application-specific integrated circuits (ASICs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), or other similar device(s); b) programmable circuitry programmed with software and/or firmware, such as one or more programmed general-purpose microprocessors, digital signal processors (DSPs) and/or microcontrollers, or other similar device(s); or c) a combination of the forms mentioned in a) and b). 19 CA 2995097 2018-02-14 [0050] Although various components of the example devices and systems are described and illustrated as a single component, in other embodiments their functions may be split among multiple different components. For example, the controller 550 used to control the functions of the smart vent 120 may in some embodiments be implemented as two or more subsystem controllers for controlling one or more of the subsystems of the smart vent, such as a main controller and a separate motor subsystem controller. [0051] Note that any and all of the embodiments described above can be combined with each other, except to the extent that it may be stated otherwise above or to the extent that any such embodiments might be mutually exclusive in function and/or structure. [0052] Although the present invention has been described with reference to specific exemplary embodiments, it will be recognized that the invention is not limited to the embodiments described, but can be practiced with modification and alteration within the spirit and scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. CA 2995097 2018-02-14
