Patent Publication Number: US-2022224861-A1

Title: Device for monitoring vehicle occupant(s)

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 16/691,633, filed on Nov. 22, 2019, entitled “DEVICE FOR MONITORING VEHICLE OCCUPANT(S),” the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD AND BACKGROUND OF THE DISCLOSURE 
     The present invention, in some embodiments thereof, relates to a device for monitoring one or more vehicle occupants, and more particularly, but not exclusively, to a device for monitoring one or more vehicle occupants that is mountable on the roof of a car. 
     Automated object detection methods and systems, especially for monitoring people in a vehicle, are attracting a continuously growing attention as they may be applied for a plurality of systems, services and/or applications ranging from commercial applications, entertainment applications to automated and/or autonomous vehicles and many more. 
     This application makes reference to International Application No. IL2018/051307 (Publication WO2019/111244) entitled “Systems and Methods for Adjustment of Vehicle Sub-Systems Based on Monitoring of Vehicle Occupant(s)” filed Nov. 29, 2018, which claims priority to U.S. Provisional Patent Application No. 62/594,043 entitled “Vehicle Intra Passenger Compartment Monitoring and Applications” filed Dec. 4, 2017; International Application No. PCT/IL2018/050761 (Publication WO2019/012534) entitled “Visual, Depth and Micro-Vibration Data Extraction Using a Unified Imaging Device” filed Jul. 12, 2018, which claims priority to U.S. Provisional Patent Application No. 62/531,417, entitled “Systems and Methods for Acquiring Information From an Environment” filed Jul. 12, 2017; International Application No. PCT/IL2018/050762 (Publication WO2019/012535) entitled Systems and Methods for Acquiring Information From an Environment” filed Jul. 12, 2018 which claims priority to U.S. Provisional Patent Application No. 62/531,417 of the same title, filed Jul. 12, 2017; and International Application No. PCT/IL2015/051255 (Publication WO2016/103271) entitled “System and Method for Detecting Surface Vibrations” filed Dec. 27, 2015, the contents of each of which are incorporated herein by reference in their entirety. 
     The above-referenced patent applications disclose various methods for detecting and analyzing movements of passengers in motor vehicles. 
     SUMMARY OF THE DISCLOSURE 
     The design of vehicular monitoring devices must adequately account for limitations in the design of such devices. Such limitations may result from considerations such as minimization of size, ensuring adequate field of view, and accounting for heat generated by the optical components. 
     In particular, a vehicular monitoring device that is mounted in the roof of a vehicle must be capable of imaging an entire field of view of an interior of a vehicle. This field of view is typically a hemisphere. When the device operates by projecting two laser patterns onto the interior of the vehicle, each laser pattern is projected onto an area covering 60×90 degrees, thus covering together 120×90 degrees. Each laser projector thus covers only a portion (60×90 degrees) of the 180 degree field of imaging. This design overcomes the need to produce an extremely large coverage diffractive optical element. It is difficult to produce a single laser and diffractive optical element capable of covering a large field of view. This difficulty stems from two reasons. First, it is challenging to produce a diffractive optical element that is able to diffract the laser pattern across such an angular span of a typical passenger vehicle, while simultaneously preserving eye safety limits. In particular, increasing the field of view for diffractive optical elements may result in tighter requirements for manufacturing tolerances. Due to manufacturing limitations, such requirements might cause reduced performance, such as an increase in the amount of light that is transmitted in the diffractive optical element&#39;s zero-order power (i.e., without any diffraction), which leads to a violation of eye safety limits. Second, the structured light source, such as a laser, in such a system consumes a relatively large amount of power, and generates excess heat. 
     Another challenge in producing vehicular monitoring systems is managing the heat generated by each of the components of the system, such as the laser, LEDs, the camera, and the control elements. 
     Yet another challenge in producing vehicular monitoring systems is that stray light can propagate through plastic elements to a lens of a camera. The design of the system thus must ensure that the camera does not capture undesired light. 
     Yet another challenge in producing vehicular monitoring systems is that a processing module is required to analyze the images generated by the camera and to evaluate changes in the images. The processing module also produces a large amount of heat, and also takes up valuable space in the vehicle&#39;s roof. 
     Yet another challenge in producing vehicular monitoring systems is ensuring that the system is compact, so that it will be easy to install, aesthetically pleasing, and unobtrusive. 
     Accordingly, it is an object of this invention to develop a device which is capable of producing and analyzing image patterns for detecting movements of passengers of vehicles. It is a further object of this invention to develop a device which produces an image whose field of view extends throughout the vehicle. It is a further object of this invention to develop such a device which is capable of dissipating heat generated by the optical components and computing components thereof, so that generated heat will not damage the components of the device. It is a further object of this invention to develop a device which is compact, easy to install, aesthetically pleasing, and unobtrusive. 
     According to a first aspect, a device for monitoring occupants of seats in a passenger compartment of a vehicle comprises a heat sink divided into a plurality of sections. Each of the sections comprises a base and a plurality of cooling fins. The bases extend along a common axis and defining a central niche therebetween. The device further comprises a plurality of structured light sources. Each of the plurality of structured light sources is attached to one of the plurality of sections and has an optical element for forming a structured light pattern. The plurality of structured light sources are oriented along the common axis and at oblique angles to the central niche, such that the plurality of structured light patterns, in combination, are directed such that they would cover occupants of seats of the vehicle. A camera is attached to the niche and configured to capture image patterns resulting from distortion of the plurality of structured light patterns by the occupants of the seats. 
     Advantageously, the heat sink serves as a stable base for each of the optical components, and also dissipates heat generated by the structured light sources, so that the generated heat will not damage the optical components. In addition, the orientation of structured light sources along the common axis and at oblique angles to the central niche causes the structured light sources to cover a wide, hemispherical field of view, which captures the entire interior of the vehicle, and which enables the device to be compact. 
     In another implementation according to the first aspect, the plurality of structured light patterns, in combination, are directed such that they would cover all of the occupants of the seats. Advantageously, the device may thus be used to provide information regarding each of the occupants of the vehicle. 
     In another implementation according to the first aspect, the plurality of structured light sources comprises two structured light sources, and each of the two light sources transmits a structured light pattern onto approximately half of a field of view of the camera. Advantageously, dividing the field of view of the camera between two structured light sources mitigates some of the challenge of producing a suitable optical element, because each structured light source needs to be spread only through half the vehicle. In addition, the power consumption and heat generated by each of the structured light sources is similarly reduced. Another advantage of this embodiment is that it permits creation of a symmetric structure for the device as well as for the generated structured light pattern, which simplifies the development of an algorithm for analyzing the images. The symmetric structure is also simpler to integrate into the vehicle. The generated structured light pattern may also assume a more rounded shape, because the center of each structured light source is tilted to the side of the center of the vehicle. 
     In another implementation according to the first aspect, each of the plurality of structured light sources is attachable to the base at a plurality of angular orientations. Advantageously, the angular orientation of the structured light sources may be adjusted so that the structured light pattern will match the shape of the interior of the vehicle. 
     In another implementation according to the first aspect, a plurality of unstructured light sources are arranged to illuminate an area targeted with the plurality of structured light patterns. Advantageously, the unstructured light sources may be used to illuminate the interior of the vehicle for capturing of videos by the camera. 
     Optionally, the camera extends further outward from the heat sink base than each of the plurality of unstructured light sources. Advantageously, this orientation prevents stray light from propagating through plastic elements to the camera lens. 
     In another implementation according to the first aspect, processing circuitry is configured to analyze changes in the captured image patterns due to movements of the occupants of the seats. Advantageously, the system may thus be used to monitor the occupants of the seats, for example, for attentiveness or health. Optionally, the processing circuitry includes a processor remotely connected to the camera via serial communication. Advantageously, remote connection of the processor allows the device to take less space within the interior of the vehicle and reduces the heat generated by the device in the area of the optical components. 
     In another implementation according to the first aspect, the device includes a control board for controlling operation of the camera and structured light sources. The control board may control, for example, whether the camera and structured light sources are on or off. 
     In another implementation according to the first aspect, the fins of the heat sink extend from the base in a direction opposite the attachment points of the plurality of structured light sources and plurality of unstructured light sources. In another implementation according to the first aspect, the fins of the heat sink extend in an orientation that is essentially vertical relative to the ground, when the device is installed in a vehicle. Advantageously, the heat sink is thus configured to dissipate heat generated by the structured light sources. This is especially the case when the fins of the heat sink are oriented vertically. 
     In another implementation according to the first aspect, the base of each section of the heat sink and the niche function as an optical bench for the camera and the plurality of structured light sources. Advantageously, the dual function of the heat sink allows the device to be compact. 
     In another implementation according to the first aspect, the heat sink is made of one of aluminum casting, thermo-plastic molding, sheet metal, or a mix thereof. Advantageously, these materials are effective at dissipating heat as well as for serving as a stable base for the optical components. 
     In another implementation according to the first aspect, a motor vehicle includes the device attached to a body of an interior cabin thereof. The device may be integrated within the roof of the interior of the vehicle cabin, may be mounted onto the interior of the vehicle cabin, or may be integrated into an over-head console in the vehicle. 
     According to a second aspect, a method of monitoring occupants of seats in a passenger compartment of a vehicle is disclosed. The method comprises transmitting a plurality of structured light patterns from a plurality of structured light sources onto occupants of seats of the vehicle. Each of the plurality of structured light sources is attached to a base of one of a plurality of heat sinks. Each of the heat sinks comprises the base and a plurality of cooling fins. The bases extend along a common axis and define a central niche therebetween. The plurality of structured light sources are oriented along the common axis and at oblique angles to the central niche, such that the plurality of structured light patterns, in combination, are directed such that they would cover all of the occupants of seats of the vehicles. The method further comprises capturing, with a camera attached to the niche, image patterns resulting from distortion of the structured light patterns by the occupants of the seats. 
     Advantageously, the heat sink serves as a base for each of the optical components, and also dissipates heat generated by the structured light sources, so that the generated heat will not damage the optical components. In addition, the orientation of structured light sources along the common axis and at oblique angles to the central niche causes the structured light sources to cover a wide, hemispherical field of view, which captures the entire interior of the vehicle. 
     In another implementation according to the second aspect, the method further comprises illuminating, with a plurality of unstructured light sources, an area targeted by the plurality of structured light patterns, and capturing with the camera images of said area illuminated by the unstructured light sources. Advantageously, the unstructured light sources may be used to illuminate the interior of the vehicle for capturing of videos by the camera. 
     In another implementation according to the second aspect, the capturing step comprises capturing image patterns resulting from distortion of the structured light patterns by all of the occupants of the seats. Advantageously, the device may thus be used to provide information regarding each of the occupants of the vehicle. 
     In another implementation according to the second aspect, the plurality of structured light sources comprises two structured light sources, and the transmitting step comprises transmitting a structured light pattern from each of the two structured light sources onto approximately half of a field of view of the camera. Advantageously, dividing the field of view of the camera between two structured light sources mitigates the challenge of producing a diffractive optical element with a large field of regard or field of view, because each structured light source needs to be spread only through half the vehicle. In addition, the power consumption and heat generated by each of the structured light sources is similarly reduced. Another advantage of this embodiment is that it permits creation of a symmetric structure for the device as well as for the generated structured light pattern, which simplifies the development of an algorithm for analyzing the images. The generated structured light pattern may also assume a more rounded shape, because the center of each structured light source is tilted to the side of the center of the vehicle. 
     In another implementation according to the second aspect, the method further comprises adjusting the angular orientation of one or more of the plurality of structured light sources on the base. Advantageously, the angular orientation of the structured light sources may be adjusted so that the structured light pattern will match the shape of the interior of the vehicle. 
     In another implementation according to the second aspect, the method further comprises analyzing with a processor changes in the captured image patterns due to movements of the occupants of the seats. Advantageously, the method may thus be used to monitor the occupants of the seats, for example, for attentiveness or health. 
     In another implementation according to the second aspect, the method further comprises mounting the device onto a body of the vehicle in a configuration suitable for monitoring occupants of the vehicle. 
     According to another aspect of the present disclosure, a device for monitoring occupants of seats in a passenger compartment of a vehicle includes a plurality of structured light sources. Each of the plurality of structured light sources is attached to one of a plurality of sections and has an optical element that forms a structured light pattern. The plurality of structured light sources are oriented such that the plurality of structured light patterns, in combination, are directed such that they would cover the occupants of the seats of the vehicle. The plurality of structured light patterns, in combination, are directed such that they would cover all occupants of the seats. A camera is attached to a central niche and is configured to capture image patterns that result from distortion of the plurality of structured light patterns by the occupants of the seats. 
     According to still another aspect of the present disclosure, a device for monitoring occupants of seats in a passenger compartment of a vehicle includes a plurality of structured light sources. Each of the plurality of structured light sources is attached to one of a plurality of sections and has an optical element that forms a structured light pattern. The plurality of structured light sources are oriented along a common axis and at oblique angles to a central niche, such that the plurality of structured light patterns, in combination, are directed such that they would cover the occupants of the seats of the vehicle. The plurality of structured light patterns, in combination, are directed such that they would cover all occupants of the seats. A plurality of unstructured light sources are arranged to illuminate an area targeted with the plurality of structured light patterns. A camera is attached to the central niche and is configured to capture image patterns that result from distortion of the plurality of structured light patterns by the occupants of the seats. The plurality of structured light sources include two structured light sources. Each of the two light sources transmits a structured light pattern onto approximately half of a field of view of the camera. 
     According to yet another aspect of the present disclosure, a device for monitoring occupants of seats in a passenger compartment of a vehicle includes a heat sink that is divided into a plurality of sections. Each of the sections includes a base and a plurality of cooling fins. The bases extend along a common axis and define a central niche therebetween. The device also includes a plurality of structured light sources, each of which are attached to one of the plurality of sections and has an optical element that forms a structured light pattern. The plurality of structured light sources are oriented along the common axis and at oblique angles to the central niche, such that the plurality of structured light patterns, in combination, are directed such that they would cover the occupants of the seats of the vehicle. The plurality of structured light patterns, in combination, are directed such that they would cover all occupants of the seats. A plurality of unstructured light sources are arranged to illuminate an area targeted with the plurality of structured light patterns. The plurality of structured light sources and the plurality of unstructured light sources are oriented along the common axis at oblique angles relative to the central niche. The plurality of structured light sources define generated fields directed toward sides of the vehicle. A camera is attached to the central niche and is configured to capture image patterns that result from distortion of the plurality of structured light patterns by the occupants of the seats. 
     Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. 
       In the drawings: 
         FIG. 1  is a left front perspective view of a device for monitoring occupants of seats in a passenger compartment of a vehicle, according to embodiments of the invention; 
         FIG. 2  is a front elevational view of the device of  FIG. 1 , according to embodiments of the invention; 
         FIG. 3  is an upper perspective view of the device of  FIG. 1 , according to embodiments of the invention; 
         FIG. 4  is a right side elevational view of the device of  FIG. 1 , according to embodiments of the invention; 
         FIG. 5  is a left side elevational view of the device of  FIG. 1 , according to embodiments of the invention; 
         FIG. 6  depicts an image of a laser pattern that is viewable by a camera of the device of  FIG. 1  when installed in a motor vehicle, according to embodiments of the invention; 
         FIGS. 7A and 7B  depict the field of coverage within a vehicle of laser patterns generated by the device when installed in a motor vehicle, according to embodiments of the invention; 
         FIG. 8  is a partially exploded view of the device of  FIG. 1 , depicting elements of a laser assembly; 
         FIGS. 9A-9C  are embodiments of the device of  FIG. 1  with the laser assembly oriented at different vertical angles; 
         FIG. 10  is the device of  FIG. 1  with a cover attached thereto; 
         FIGS. 11A and 11B  depict an interior of a motor vehicle and various locations therein at which the device of  FIG. 1  may be attached; 
         FIG. 12  depicts the device of  FIG. 1  with a mounting bracket for mounting onto a vehicle, according to embodiments of the invention; and 
         FIGS. 13A and 13B  depict a mounting structure for the device of  FIG. 1  suitable to be installed in a vehicle, according to embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to a device for monitoring one or more vehicle occupants, and more particularly, but not exclusively, to a device for monitoring one or more vehicle occupants that is mountable in the roof of a car. 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. 
     As used in this disclosure, the term “optical component” includes any device suitable for generating light or for capturing light as part of an optical system, including, but not limited, to a laser, an LED, or a camera. 
     As used in this disclosure, the term vehicle means a road based vehicle, for example, a car, a truck, a van, a minivan, a bus, a pick-up truck, a fire truck, an ambulance, a taxi, and a snow removal truck. The vehicle may be an autonomously driven vehicle, a manually driven vehicle, or a semi-autonomous semi-manual driven vehicle. 
     As used in this disclosure, the terms intra passenger compartment, interior of a vehicle, and cabin may be interchanged. The term vehicle may sometimes refer to the cabin of the vehicle. 
     As used in this disclosure, the term occupant refers to the driver and/or passengers, which may be sitting at any of the designated seats in the cabin of the vehicle. The occupant may be a human or another living being, e.g., a pet. 
     Referring to  FIGS. 1-5 , device  10  is a device for monitoring occupants of seats in a passenger compartment of a vehicle. Heat sink  12  serves as a base for other components of the device  10 . Heat sink  12  may be formed of any material suitable to be both a heat sink and a base for other materials, including, but not limited to, aluminum casting, thermo-plastic molding, sheet metal, or a mix thereof. 
     Heat sink  12  is divided into two symmetrical sections  14 ,  16 . Left section  14  includes heat sink base  24  and heat sink cooling fins  28 , and right section  16  includes heat sink base  26  and cooling fins  30 . The heat sink bases  24 ,  26  and the cooling fins  28 ,  30  are oriented substantially perpendicular to each other, and each of the cooling fins  28 ,  30  is oriented substantially parallel to each other. This orientation maximizes the cooling efficiency of the heat sink  12 , as is known to those of skill in the art. In the illustrated embodiment, each section  14 ,  16  has four cooling fins  28 ,  30 ; however, there may also be fewer or more cooling fins  28 ,  30 . In addition, cooling fins  28 ,  30  are depicted as straight fins. However, cooling fins  28 ,  30  may also be pins or flared fins. 
     Each of the sections  14 ,  16  has an unstructured light source  32  and a structured light source  36  attached thereto. In the depicted embodiment, the unstructured light sources  32  are arrays of light emitting diodes (LEDs)  34 , arranged on LED board  33 , and powered by LED power connector  35 . 
     The structured light sources  36  may be laser assemblies, for example, Class I lasers. Laser assemblies  36  are attached to the sections  14 ,  16  with brackets  40 . Each laser assembly may consist of a plurality of lasers that are collimated or semi-collimated, in the manner described at pages 7-10 of International Application No. PCT/IL2018/050762 (Publication WO2019/012535). The lasers may transmit light in the visual range, and/or the near-infrared range. In exemplary embodiments, the lasers transmit a beam at 830 nm or at 940 nm. Optical elements  38  are embedded within structured light sources  38 . Optical elements  38  may be diffractive optical elements. Optical elements  38  may split a beam (collimated or not collimated) generated by structured light sources  36  into a structured light pattern. 
     Niche  18  is configured at the center of device  10 . Sections  14 ,  16  extend along a common axis, and define niche  18  therebetween. Structured light sources  36  and unstructured light sources  32  are oriented along the common axis, at oblique angles to the niche  18 . 
     Camera  20  is mounted onto the heat sink base  12  within niche  18 . In one embodiment, the camera  20  is a CMOS image sensor with resolution of 1944×1204, or 2.3 megapixels. Camera  20  may include a photodiode array, as disclosed in International Application No. PCT/IL2015/051255 (Publication WO2016/103271). The camera  20  may detect light in the visual range and/or the near infrared range. 
     Lens  22  is configured at the end of the camera  20 . Lens  22  may be an afocal fisheye lens. In an exemplary embodiment, lens  22  may have a field of view of 180 degrees, an image circle 3.5 mm diameter, and an equivalent focal length of 1.05 mm. Camera  20  and lens  22  may have the characteristics of the camera and lens described at page 11 of International Application No. PCT/IL2018/050762 (Publication WO2019/012535), and pages 29-30 of International Application No. IL2018/051307 (Publication WO2019/111244). 
     Camera  20  extends further outward from the heat sink base  12  than each of the plurality of unstructured light sources  32  and structured light sources  36 . This extension of the lens  22  prevents stray light from propagating through plastic elements (e.g., plastic material used to cover device  10 ) to the camera lens  22 . Thus, light from the interior of the cabin is captured by the lens  20 , without any interference from components of device  10  itself. 
     As can be seen best in  FIGS. 1-3 , sections  14 ,  16  and niche  18  serve a dual function of both a heat sink and an optical bench (for structured light sources  36 , unstructured light sources  32 , and camera  20 ). This dual function helps device  10  be manufactured compactly. 
     Heat sink  12  may be made of any material suitable for functioning both as a heat sink and as an optical bench. To serve as an optical bench, especially for the structured light sources  36 , the heat sink base  12  needs to have high dimensional stability (rigidity). This stability is quantifiable by angular tolerance. In exemplary embodiments, the camera  20  to laser assembly  36  alignment is kept fixed to 1/16 of a degree over the life time of the device  10  and across varying environmental conditions. Exemplary materials include aluminum casting, thermo-plastic molding, sheet metal, or a mix thereof. These materials are effective at dissipating heat as well as for serving as a base for the optical components. 
     Referring back to the heat sink  12 , and as seen best in  FIGS. 1 and 3 , the cooling fins  28 ,  30  of the heat sink  12  extend from the heat sink bases  24 ,  26 , in a direction opposite the attachment points of structured light sources  36  and unstructured light sources  32 . The heat sink is thus configured to maximize its dissipation of heat generated by the structured light sources  36  and unstructured light sources  32 . Specifically, heat that is generated by the structured light sources  36  and unstructured light sources  32  is transferred from the heat sink base  12  to the cooling fins  28 ,  30 , and is dissipated through the flow of air between cooling fins  28 ,  30 . This mechanism of heat dissipation is based on the principles of natural convection, as is known to those of skill in the art. In the illustrated embodiment, the cooling fins  28 ,  30  extend in an orientation that is essentially vertical relative to the ground (when the device  10  is installed in a vehicle). An advantage of this embodiment is that natural convection principles typically result in more effective cooling when the cooling fins  28 ,  30  are oriented vertically. 
     Device  10  also includes control board  42 . Control board  42  may be implemented, for example, as a central processing unit(s) (CPU), field programmable gate array(s) (FGPA), digital signal processor(s) (DSP), and application specific integrated circuit (ASIC). Control board  42  controls operation of the camera  20 , structured light sources  36 , and unstructured light sources  32 . For example, control board  42  may receive and implement instructions whether to turn on the device  10  and/or components thereof. For example, control board  42  may implement instructions to activate device  10  whenever a door to the vehicle is opened, or whenever the vehicle is turned on. Control board  42  may also be configured to include internal feedback loops between various components of device  10 . For example, control board  42  may be used to switch the device  10  between operating using the structured light sources  36  and the unstructured light sources  32 , as will be discussed below. Control board  42  may also be used to coordinate operation of the light sources  32 ,  36  in sync with the camera  20 . Control board  42  may be configured to receive instructions from a user, e.g., to activate device  10 , or components thereof. Control board  42  need not be configured in the precise location depicted in  FIGS. 1-5 , but rather may be located in any location suitable for effecting the operations described above. 
     Referring to  FIGS. 6, 7A and 7B , operation of device  10  using structured light sources  36  is now described. As shown in  FIG. 6 , structured light sources  36  generate a structured light pattern  200  in vehicle  100 . As discussed above, the structured light pattern  200  is generated by passing light generated by the light sources  36  through an optical element  38 , which may be a diffractive optical element. Structured light pattern  200  is a two-dimensional matrix. The structured light pattern may be a laser pattern, as described in International Application No. IL2018/051307 (Publication WO2019/111244) International Application No. PCT/IL2018/050761 (Publication WO2019/012534; International Application No. PCT/IL2018/050762 (Publication WO2019/012535), and International Application No. PCT/IL2015/051255 (Publication WO2016/103271). As shown schematically in  FIG. 7A , device  10  is mounted within vehicle  100  such that aggregated field  210  of structured light pattern  200  covers the entire passenger cabin of vehicle  100 . When there are two structured light sources  36 , each of the two structured light sources  36  transmits a structured light pattern  200  covering partial field  212 ,  214  onto approximately half of the cabin of the vehicle  100 , as shown in  FIG. 7B . Partial fields  212 ,  214 , in combination, are directed such that they cover occupants of seats of the vehicle  100 . 
     Using two (or more) structured light sources  36  to generate partial fields  212 ,  214  provides distinct advantages over using generating a single field  210 . Any field generated by structured light source  36  and optical element  38  is necessarily limited by the size and diffractive capabilities of optical element  38 . It is easier to develop and manufacture an optical element  38  that is required to diffract a laser beam to cover only half the field of coverage of a vehicle, compared to an optical element for covering a full field of coverage of a vehicle. In addition, using two or more structured light sources  36  reduces the power consumption of each structured light source  36 . This, in turn, reduces the excess heat generated by the light sources  36 . In addition, the generated fields  212 ,  214  may assume a more rounded shape, because the center of each structured light source  36  is tilted to the side of the center of the vehicle  100 . This rounded shape, in turn, allows for greater coverage of the edges of the cabin of the vehicle  100 , which allows device  10  to be manufactured more compactly. 
     As seen in  FIG. 7B , because the structured light sources  36  are oriented at oblique angles to the central niche, a small central section  216  of the cabin, directly in front of the camera  20 , is not included in either of partial fields  212  or  214 . In a typical passenger vehicle, this central section  216  (the center of the front seating area of the cabin) is never occupied by a passenger, and thus it is not necessary to detect movements of passengers in that spot. In addition, the orientation of the structured light sources  36  at oblique angles helps ensure full coverage of the peripheral areas of the vehicle (e.g., to monitor a passenger resting against the side of the vehicle&#39;s cabin). Thus, in the depicted embodiment, the plurality of structured light patterns, in combination, are directed such that they would cover all of the occupants of the seats. When device  10  is configured to be installed in a vehicle with passengers seated across the front row (e.g., a truck with a bench seat) device  10  may be configured to generate a structured light pattern which also covers the central section  216  not covered by the field  200  shown in  FIG. 7B . 
     As discussed, device  10  generates a structured light pattern  200  which is projected from the structured light sources  36  onto the occupants of the seats. This structured light pattern  200  is detectable by camera  20 . In the depicted embodiment, in which there are two structured light sources  36 , each structured light source  36  transmits a structured light pattern onto approximately half of the field of view of the camera. 
     All objects within the vehicle cause a distortion in the structured light pattern  200 . Such objects include, but are not limited, to occupants, removable objects, vehicle elements, and vehicle structures. The distortions generated by fixed objects typically do not change, even as the vehicle is moving. By contrast, microvibrations caused by movement of occupants of the vehicle cause changes in the laser pattern  200 . The camera images the laser pattern  200  at regular intervals. Processing circuitry connected to the camera  20  then compares the imaged speckle patterns and evaluates whether the laser pattern  200  has changed, e.g., due to microvibrations. The operation of device  10  may further correspond with the descriptions found in the above-referenced patent applications. 
     Device  10  further comprises a serial link to processing circuitry (not shown). The processing circuitry is located at sufficient distance from the device  10  so that the heat generated by processing circuitry does not damage the optical components. For example, the processing circuitry may be embedded within the roof of the vehicle  100 , or under the dashboard of the vehicle  100 . 
     The processing circuitry is configured to analyze changes in the image patterns captured by camera  20 , due to movements (e.g., microvibrations) by occupants of the seats. The processing circuitry may employ one or more algorithms to evaluate the changes in the image patterns, as discussed the above-referenced patent applications. For example, an absence of significant changes in the laser pattern  200  may indicate that the occupant of the vehicle is in medical distress. As another example, the processing circuitry may detect whether the driver is distracted, for example, by a mobile device. In the depicted embodiment, development of the algorithm may be simplified because the structured light sources  36  project a symmetric laser pattern around a centerline of the vehicle  100 . The processing circuitry also may extract depth information about passengers and other objects in the vehicle. 
     The processing circuitry may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Operation of device  10  using unstructured light sources  32  is now described. In this configuration, the structured light sources  36  are turned off, so that no laser pattern  200  is formed on the occupants of the vehicle. Thus, the camera  20  images the occupants of the vehicle without a laser pattern overlay. For example, unstructured light sources  32  may be used to illuminate the interior of the vehicle when the camera  20  is recording a video. Images of the occupants of the vehicle may be used for evaluation of safety or well-being parameters that cannot be measured with the laser patterns, for example, eyelid detection or gaze detection. Unstructured light sources  32  provide illumination so that the camera  20  will have sufficient light to image the occupants of the vehicle. The use of unstructured light sources  32  is optional, and in an environment with sufficient ambient light, the camera  20  may operate without additional light generated by the unstructured light sources  32 . 
     In one exemplary embodiment of operation of the device  10 , the device  10  alternates in a frame-by-frame bases between the use of structured light sources  36  and the use of unstructured light sources  32 . Thus, the camera  20  is capable of monitoring, in continuous sequence, safety features that are tracked with the aid of the structured light sources  36  (e.g., movements of the passengers) and safety features that are tracked with the aid of the unstructured light sources (e.g., gaze detection). 
       FIGS. 8 and 9A-9C  illustrate a mechanism for adjusting angular orientation that may optionally be included in device  10 . In  FIG. 8 , structured light source  36  is depicted as a laser assembly in an exploded view. The internal components of structured light source  36  include laser lens (e.g., a collimating lens)  52 , laser barrel  54 , laser photodiode  56 , and laser  58 . Optical element  38  is secured onto structured light source  36  with optical element cage  50 , which attaches to the front-most portion of structured light source  36 . The entire structured light source  36  may be securely attached to sections  14 ,  16  of device  10  by being fitted into cavity  41  of bracket  40 . 
     As illustrated in  FIGS. 9A-9C , cavity  41  in bracket  40 , which is adapted for insertion of laser assembly  36 , may be oriented at different angles. For example, the cavity of bracket  40   a  is tilted at a higher angle relative to the bracket  40   b , which is tilted at a higher angle relative to bracket  40   c . The angles of brackets  40   a - 40   c  are merely exemplary, and any other angle may be used. Choosing between brackets  40   a ,  40   b , and  40   c  allows the structured light source  36  to be attachable to the base at a plurality of angular orientations. By adjusting the angular orientation, it is possible to adapt device  10  to different configurations of vehicle cabins. 
     Alternatively, if the device  10  is manufactured for the dimensions of a particular vehicle, the angle of the bracket  40  may be preselected during manufacture of device  10 . In such instances, it will be unnecessary to tinker with the angle of the bracket  40  when installing the device  10 . 
     Turning to  FIG. 10 , device  10  may be equipped with cover  60 . Cover  60  may be comprised of front section  62  and rear section  64 , which fit together over device  10 . Front section  62  and rear section  64  may be snap fit together, or may otherwise be joined together using any mechanism known to those of skill in the art. Front section  62  includes structured light source windows  66  and unstructured light source windows  68 . Windows  66  cover structured light sources  36 , and windows  68  cover unstructured light sources  32 . The windows  66 ,  68  each are of a material that permits passage of light, such as glass, polyethylene, or polycarbonate. The structured light source windows  66  are of a material that does not interfere with the transmission of the structured light patterns. Preferably, the windows are transparent to light in the infrared spectrum but opaque to light in the visible spectrum. In this embodiment, the windows  66  permit light from the structured light sources  36  to pass through the cover  60 , while an observer is unable to see through cover  60 , for aesthetic reasons. Cover  60  also includes camera cover  70 . Camera cover  70  is fitted around camera  20  and covers niche  18 . Camera cover  70  does not cover lens  22 , so that lens  22  will receive and process the laser pattern reflected from the occupants of the vehicle, without any interference or distortion. 
     Cover  60  also includes vents  72 . Vents  72  permit heat that is dissipated by heat sink  12  to escape the cover  60 , so that the dissipated heat does not become trapped within the cover  60  and damage the optical components of device  10 . 
       FIGS. 11A and 11B  illustrate a mechanism for mounting device  10  into vehicle  100 , in a location suitable for monitoring occupants of the vehicle  100 . Device  10  may be attached to vehicle  100  at attachment location  102   a ,  102   b , or  102   c . Attachment locations  102   a - c  are located in the roof of the cabin, at or near the front of the vehicle  100 . Attachment location  102   a - c  may be selected in order to maximize the field of coverage  210  of the laser pattern  200 , and the field of view of the camera  20 , as discussed above. Typically, the field of coverage  210  and the field of view of the camera  20  are maximized when the device  10  is mounted at the front of the vehicle  100  and as high as possible. The depicted attachment locations  102   a - c  are merely exemplary, and any other suitable attachment location may be chosen. For example, the device may also be incorporated into the vehicle  100  overhead console. 
       FIGS. 12, 13A, and 13B  schematically depict mounting materials that may be used to mount device  10  into a vehicle  100 .  FIG. 12  depicts bracket  300 , which is suitable for mounting device  10  onto a previously finished vehicle. Bracket  300  may be built into, or attached too, the roof of vehicle  100  (for example, at one of attachment locations  102   a - c  depicted in  FIGS. 11A and 11B ).  FIGS. 13A and 13B  depict casing  400 , which is suitable for being built into a roof of a vehicle  100  during manufacture. In the embodiment of  FIGS. 13A and 13B , a cavity is thus built directly into the roof of vehicle  100  that is suitable for fixation of device  10 . 
     It is expected that during the life of a patent maturing from this application many lasers, light emitting diodes, structured light sources, and unstructured light sources, will be developed and the scope of the terms laser, diode, structured light source, and unstructured light source is intended to include all such new technologies a priori. 
     As used herein the term “about” refers to   10%. 
     The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”. This term encompasses the terms “consisting of” and “consisting essentially of”. 
     The phrase “consisting essentially of” means that the composition or method may include additional ingredients and/or steps, but only if the additional ingredients and/or steps do not materially alter the basic and novel characteristics of the claimed composition or method. 
     As used herein, the singular form “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof. 
     The word “exemplary” is used herein to mean “serving as an example, instance or illustration”. Any embodiment described as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments and/or to exclude the incorporation of features from other embodiments. 
     The word “optionally” is used herein to mean “is provided in some embodiments and not provided in other embodiments”. Any particular embodiment of the invention may include a plurality of “optional” features unless such features conflict. 
     Throughout this application, various embodiments of this invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. 
     Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases “ranging/ranges between” a first indicate number and a second indicate number and “ranging/ranges from” a first indicate number “to” a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals therebetween. 
     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 subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. 
     All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety.