Patent Publication Number: US-11662061-B2

Title: Power tool safety system

Description:
RELATED APPLICATIONS 
     This continuation application claims priority on copending U.S. application Ser. No. 16/533,538 filed on Aug. 6, 2019, and entitled “POWER TOOL SAFETY SYSTEM”, which claims priority on U.S. Provisional Application Ser. No. 62/724,324 filed on Aug. 29, 2018, and entitled “POWER TOOL SAFETY SYSTEM”. To the extent permitted, the contents of U.S. Provisional Application Ser. No. 62/724,324 and U.S. application Ser. No. 16/533,538 are incorporated in their entirety herein by reference. 
    
    
     BACKGROUND 
     Power tools of many varieties are used by millions of individuals on a regular or periodic basis. Unfortunately, power tools can be very dangerous if used improperly or just by their inherent nature. For example, a power tool such as a power saw or power drill can easily and potentially severely injure the hand or fingers of a user, including loss of digits and worse, if the hand or fingers get too close to and/or contact the saw blade or drill bit during use of the power tool. As a further example, when using a power saw, the user physically holds an object to be cut and moves the object into the moving saw blade so that the object can be cut. This inherently places the user at risk of contacting the saw blade in the event of slipping or as a result of inattention. While guards can be used to cover portions of the saw blade, a portion of the saw blade still remains exposed to the user. 
     Thus, it is desired to provide a safety system for use with power tools that can effectively inhibit or at least mitigate the severity of injury to the user during use of the power tools. More specifically, in certain applications, it is desired to provide a safety system for use with power tools that will automatically shut down (or power off) the power tool and rapidly stop movement of moving components of the power tool if the hand or fingers of the user get too close to the moving components of the power tool. 
     SUMMARY 
     The present invention is directed toward a safety system for use with a power tool that is usable by a user, the power tool including a base and a moving component that is movable relative to the base. In various embodiments, the safety system includes a sensor assembly and a controller. The sensor assembly monitors a predetermined danger zone that is adjacent to the moving component of the power tool. The sensor assembly is configured to generate data relating to the predetermined danger zone. The controller receives the data from the sensor assembly and analyzes the data from the sensor assembly to determine if at least a portion of a hand of the user is present within the predetermined danger zone. 
     In some embodiments, the safety system further includes a wearable component that is configured to be coupled to the hand of the user. The wearable component includes infrared only reflective material. In such embodiments, the controller analyzes the data from the sensor assembly to determine if the wearable component is present within the predetermined danger zone. In certain such embodiments, the wearable component includes black infrared only reflective material. 
     Additionally, in certain embodiments, the sensor assembly includes a first sensor that monitors a first region that is adjacent to the moving component of the power tool and generates first data relating to the predetermined danger zone, and a second sensor that monitors a second region that is adjacent to the moving component of the power tool and generates second data relating to the predetermined danger zone. In such embodiments, the controller compares the first data from the first sensor and the second data from the second sensor to determine if the wearable component is present within the predetermined danger zone. In some such embodiments, the first region intersects the second region to define a common region, and the predetermined danger zone is based on the common region. 
     In some embodiments, the first sensor is a first sensor type and the second sensor is a second sensor type that is different than the first sensor type. For example, in one such embodiment, the first sensor is a red blue green input device, and wherein the second sensor is a no infrared filter input device. 
     Additionally, in certain embodiments, the safety system further incudes a braking system that is configured to selectively stop movement of the moving component of the power tool relative to the base. In such embodiments, if the controller determines that the wearable component is present within the predetermined danger zone, the controller transmits a signal to the braking system to stop movement of the moving component of the power tool relative to the base. 
     Alternatively, in other embodiments, the sensor assembly includes a first sensor that captures at least one hand image prior to the user using the power tool, and a second sensor that monitors the predetermined danger zone that is adjacent to the moving component of the power tool and generates the data relating to the predetermined danger zone. In such embodiments, the controller generates a detection algorithm that is based at least in part on the at least one hand image that is captured by the first sensor prior to the user using the power tool. Additionally, the controller analyzes the data from the second sensor utilizing the detection algorithm to determine if the at least a portion of the hand of the user is present within the predetermined danger zone. Further, in some such embodiments, the first sensor captures a plurality of hand images prior to the user using the power tool; and the controller generates the detection algorithm based at least in part on the plurality of hand images that are captured by the first sensor prior to the user using the power tool. 
     In certain embodiments, the first sensor is the same as the second sensor. 
     Further, in some embodiments, the safety system further includes a braking system that is configured to selectively stop movement of the moving component of the power tool relative to the base. In such embodiments, if the controller determines that the at least a portion of the hand is present within the predetermined danger zone, the controller transmits a signal to the braking system to stop movement of the moving component of the power tool relative to the base. 
     The present invention is further directed toward a method for protecting a hand of a user during use of a power tool, the power tool including a base and a moving component that is movable relative to the base, the method including (i) monitoring a predetermined danger zone that is adjacent to the moving component of the power tool with a sensor assembly; (ii) generating data relating to the predetermined danger zone with the sensor assembly; (iii) receiving the data from the sensor assembly with a controller; and (iv) analyzing the data from the sensor assembly with the controller to determine if at least a portion of a hand of the user is present within the predetermined danger zone. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
         FIG.  1 A  is a simplified schematic front view illustration of a power tool, and a portion of an embodiment of a power tool safety system having features of the present invention that is usable with the power tool; 
         FIG.  1 B  is a simplified schematic side view illustration of the power tool, and the portion of the power tool safety system illustrated in  FIG.  1 A ; 
         FIG.  1 C  is a simplified schematic top view illustration of a portion of the power tool and the power tool safety system illustrated in  FIG.  1 A ; 
         FIG.  1 D  is a simplified schematic top view illustration of a portion of a user, and a portion of the power tool and the power tool safety system illustrated in  FIG.  1 A ; 
         FIG.  2    is a simplified schematic top view illustration of a portion of the user, a portion of the power tool, and a portion of another embodiment of the power tool safety system; 
         FIG.  3    is a flowchart illustrating a representative example of a use of the power tool in conjunction with the power tool safety system; 
         FIG.  4    is a flowchart illustrating another representative example of a use of the power tool in conjunction with the power tool safety system; 
         FIG.  5 A  is a simplified schematic front view illustration of the power tool, and a portion of still another embodiment of the power tool safety system; and 
         FIG.  5 B  is a simplified schematic top view illustration of a portion of the user, a portion of the power tool, and a portion of the power tool safety system illustrated in  FIG.  5 A . 
     
    
    
     DESCRIPTION 
     Embodiments of the present invention are described herein in the context of a power tool safety system (also sometimes referred to herein simply as a “safety system”) for protecting a user during use of a power tool. In various embodiments, the safety system is configured to inhibit and/or minimize injury to the user during use of the power tool, e.g., by automatically shutting down and/or ceasing movement of a moving component of the power tool when certain conditions are sensed. More specifically, in such embodiments, the safety system can be configured to sense, recognize and/or identify the presence of a portion of the user, e.g., a hand or a portion of a hand of the user, within a predetermined area that is positioned near to, adjacent to, and/or substantially encircles the moving component of the power tool. The safety system can further automatically shut down and stop operation of the power tool upon sensing, recognizing and/or identifying the portion of the user within the predetermined area that is positioned near to, adjacent to, and/or substantially encircles the moving component of the power tool. 
     Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. 
     In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer&#39;s specific goals, such as compliance with application-related and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure. 
       FIG.  1 A  is a simplified schematic front view illustration of a power tool  10 , and a portion of an embodiment of a power tool safety system  12  (also referred to herein simply as a “safety system”) having features of the present invention that is usable with the power tool  10 . 
     As provided herein, the safety system  12  can be used with any suitable power tool  10 . For example, in certain non-exclusive alternative applications, the safety system  12  can be used with a band saw, a table saw, a circular saw, a miter saw, or a drill press. Alternatively, the safety system  12  can be used with any other suitable power tool  10 . Thus, although various Figures provided herewith illustrate the safety system  12  being used specifically with a band saw, such use is not intended to be limiting in any manner. 
     As shown in  FIG.  1 A , the power tool  10  includes a base  14  and a moving component  16 , e.g., a saw blade or a drill bit, that is movable relative to the base  14 . In particular, during use of the power tool  10 , the power tool  10  can be moved between a non-operating condition, where the moving component  16  is not moving relative to the base  14 , and an operating condition, where the moving component  16  is moving relative to the base  14  so as to enable the power tool  10  to perform its desired function. Additionally, as illustrated, the power tool  10  can further include an on/off (power) switch  18  that can be selectively activated by a user  20  (illustrated in  FIG.  1 D ) to selectively move the power tool  10  between the non-operating condition (i.e. the “off” condition) and the operating condition (i.e. the “on” condition). Further, in certain embodiments, the power tool  10  can also include a safety cutoff switch  22  that can be selectively activated by the user  20  for manually activating a braking system for rapidly stopping movement of the moving component  16  relative to the base  14 . The safety cutoff switch  22  is also usable to selectively energize and de-energize the power tool  10  and the safety system  12 . 
     As noted above, the safety system  12  is configured to protect the user  20 , i.e. to inhibit and/or minimize injury to the user  20 , during use of the power tool  10 . In various embodiments, the safety system  12  is configured to automatically shut down the power tool  10 , i.e. by automatically stopping movement of the moving component  16  relative to the base  14 , when certain conditions exist and/or are sensed in relation to the power tool  10 . 
     The design of the safety system  12 , and the positioning of the various components of the safety system  12  can be varied to suit the specific requirements of the power tool  10  with which the safety system  12  is being used. In various embodiments, the safety system  12  can be configured to include one or more of a wearable component  24  (illustrated, for example, in  FIG.  1 D ), a sensor assembly  26 , a controller  28 , and a braking system  30 . Alternatively, it is understood that the safety system  12  can include additional components or fewer components than what is illustrated in the Figures. For example, in certain non-exclusive alternative embodiments, the safety system  12  can be configured for use without the specific need for the wearable component  24 . Still alternatively, one or more of the components of the safety system  12  can be positioned in a different manner than what is shown in the Figures. 
     As provided herein, in various embodiments, the wearable component  24  is configured to be coupled to and/or worn by the user  20  during use of the power tool  10 . The wearable component  24  can be provided in any suitable form for use by the user  20 . In various embodiments, the wearable component  24  is configured to cover at least a portion of a hand  20 A (illustrated in  FIG.  1 D ) of the user  20 . For example, in some such embodiments, as shown in  FIG.  1 D , the wearable component  24  can be provided in the form of a glove that is to be worn on the hand  20 A of the user  20 , and covers substantially the entirety of the hand  20 A of the user  20 , during use of the power tool  10 . Alternatively, the wearable component  24  can be configured to be worn by the user  20  such that it covers less than the entirety of the hand  20 A of the user  20 . For example, in one non-exclusive alternative embodiment, the wearable component  24  can be provided in the form of a finger-tip cover that is configured to be worn on only a single finger-tip  20 B (illustrated in  FIG.  2   ) of the hand  20 A of the user  20 . 
     Additionally, the wearable component  24  can be formed from any suitable materials and/or can be any suitable colors. As provided herein, in various embodiments, the wearable component  24  is made from materials and/or includes colors that can be sensed and/or identified by the safety system  12 , i.e. the sensor assembly  26  and/or the controller  28 . For example, in certain embodiments, the wearable component  24  can include an infrared only reflective material or pigment, e.g., a black infrared only reflective material. Alternatively, the wearable component  24  can be formed from or include different materials and/or different colors than those specifically noted herein, provided that such materials and/or colors can be readily sensed or identified by the sensor assembly  26  and/or the controller  28 . 
     The sensor assembly  26  is configured to sense and/or detect the presence of the wearable component  24 , and thus the presence of at least a portion of the hand  20 A of the user  20 , i.e. in a position near and/or adjacent to the moving component  16  of the power tool  10 . In some embodiments, the sensor assembly  26  is coupled to the power tool  10  such that the sensor assembly  26  is substantially fixed in position relative to the power tool  10 , i.e. at least relative to the base  14  of the power tool  10 , during use of the power tool  10 . More particularly, in alternative such embodiments, the sensor assembly  26  can be fixedly coupled to the power tool  10  or the sensor assembly  26  can be removably coupled to the power tool  10 . Still alternatively, the sensor assembly  26  can be provided independently from the power tool  10 , but can still be configured to be fixed in position relative to the power tool  10 , i.e. at least relative to the base  14  of the power tool  10 , so as to be effectively usable with the power tool  10 . 
     The design of the sensor assembly  26  can be varied to suit the requirements of the safety system  12 . In the embodiment illustrated in  FIG.  1 A , the sensor assembly  26  includes a first sensor  26 A and a second sensor  26 B that are each positioned and configured to monitor and/or sense within an area or region that is positioned near to, adjacent to, and/or that substantially encircles the moving component  16  of the power tool  16 . In certain embodiments, the first sensor  26 A can be a first sensor type, and the second sensor  26 B can be a second sensor type that is different than the first sensor type. For example, in one such embodiment, the first sensor  26 A can be a red blue green (RBG) input device, e.g., camera or other suitable input device, that is positioned and oriented to monitor a first region  32 A, e.g., to capture images (pixels) within the first region  32 A, that is positioned near to, adjacent to, and/or that substantially encircles the moving component  16  of the power tool  10 ; and the second sensor  26 B can be a no infrared filter (NoIR) input device, e.g., a camera or other suitable input device, that is positioned and oriented to monitor a second region  32 B, e.g., to capture images (pixels) within the second region  32 B, that is positioned near to, adjacent to, and/or that substantially encircles the moving component  16  of the power tool  10 . Additionally, as provided herein, the first sensor  26 A and the second sensor  26 B can be further configured to generate data relating to the first region  32 A and the second region  32 B, respectively, that can be transmitted to the controller  28 . Alternatively, the first sensor  26 A and/or the second sensor  26 B can have a different design. 
     It is appreciated that the use of the terms “first sensor” and “second sensor” is merely for convenience and ease of illustration, and either sensor  526 A,  526 B can be referred to as the “first sensor” and/or the “second sensor”. 
     In certain embodiments, the controller  28  can be coupled to the power tool  10 , i.e. to the base  14  of the power tool  10 . Alternatively, the controller  28  can be provided remotely from the power tool  10 . 
     As provided herein, the controller  28  is configured to receive and analyze input (e.g., data) from the sensor assembly  26 , e.g., the images (pixels) captured by the first sensor  26 A and the second sensor  26 B, to determine when the wearable component  24  is within a predetermined danger zone  34  (illustrated in  FIG.  1 D ) that is established near to, adjacent to, and/or that substantially encircles the moving component  16  of the power tool  10 . As such, the controller  28  can analyze the input, data and/or images from sensors  26 A,  26 B to determine when at least a portion of the hand  20 A of the user  20  is within the predetermined danger zone  34 . With such design, the sensor assembly  26  and/or each of the sensors  26 A,  26 B can be said to be usable for monitoring the predetermined danger zone  34 . 
     Additionally, during use of the power tool  10  and the safety system  12 , the controller  28  can be used in what is sometimes referred to herein as a “glove-sensing mode” or “component-sensing mode”, as well as what is sometimes referred to herein as a “collision detection mode”. For example, when the controller  28  is in a mode for determining when the wearable component  24  is within the predetermined danger zone  34 , but the power tool  10  is not running, then the controller  28  can be said to be in the glove-sensing mode or the component-sensing mode. Conversely, when the controller  28  is in a mode for determining when the wearable component  24  is within the predetermined danger zone  34 , and the power tool  10  is running, then the controller  28  can be said to be in the collision detection mode. 
     As described in greater detail herein below, it is appreciated that in embodiments of the safety system  12  that do not include the wearable component  24 , the sensor assembly  26  can be configured to sense and/or detect the presence of the hand  20 A of the user  20  (or at least a portion of the hand  20 A of the user  20 ) in a position near and/or adjacent to the moving component  16  of the power tool  10 . Further, in such embodiments, the controller  28  can be configured to receive and analyze input (data) from the sensor assembly  26  to determine when the hand  20 A of the user  20  (or at least a portion of the hand  20 A of the user  20 ) is within the predetermined danger zone  34  near and/or adjacent to the moving component of the power tool  10 . 
     The controller  28  and the circuitry provided therewith can have any suitable design. For example, in some embodiments, the controller  28  includes a single board computer (SBC) having one or more processors or circuits for purposes of analyzing the input, data and/or images (i.e. the pixels within the corresponding regions  32 A,  32 B) generated and/or captured by the first sensor  26 A and the second sensor  26 B. 
     Additionally, in certain embodiments, the controller  28  can incorporate one more visual outputs, e.g., LED lights, that alert the user  20  regarding the status of the power tool  10  and/or the safety system  12 . For example, in such embodiments, the controller  28  can include visual outputs indicative that the power tool  10  is in a no start (non-operating) condition, a can start condition, and a running (operating) condition; as well as a visual output regarding activation of the safety system  12 , i.e. identifying a collision detection when the wearable component  24  is determined to be within the danger zone  34 . In certain embodiments, it is further appreciated that the safety system  12  and/or the controller  28  can be configured to sense or monitor movement of the user  20 , e.g., at least a portion of the hand  20 A of the user  20 , near or within the predetermined danger zone  34 . For example, in some such embodiments, the safety system  12  and/or the controller  28  can be configured to sense or detect movement of at least a portion of the user  20  above a predetermined velocity generally toward the moving component  16  of the power tool  10 , when such movement is at least is close proximity to the predetermined danger zone  34 . 
     Further, the controller  28  can incorporate the use of any system of electrical connections, e.g., relays, General Purpose Input/Output (GPIO) connections, etc., for purposes of electrically connecting the controller  28  with the sensor assembly  26  and the braking system  30 , as well as electrically connecting various components within the controller  28 . 
     The general concept of sensing and/or identifying when the wearable component  24  and/or at least a portion of the hand  20 A of the user  20  may be positioned within the danger zone  34  will now be described. In particular, utilizing an RGB input device as the first sensor  26 A enables the controller  28  to receive as input the full color spectrum of the area near, adjacent to and/or substantially encircling the moving component  16  of the power tool  10 . Conversely, the NoIR input device as the second sensor  26 B contains a no infrared filter and produces a near gray scale image (with infrared backlighting) of the area near, adjacent to and/or substantially encircling the moving component  16  of the power tool  10 . Thus, the infrared reflective material that is included on the wearable component  24  will appear black in the region  32 A monitored by the first sensor  26  (e.g., the RGB camera frame) and bright white in the region  32 B monitored by the second sensor  26 B (e.g., the NoIR camera frame). 
     During use of the safety system  12 , both sensors  26 A,  26 B are aligned to a central origin in front of the moving component  16  of the power tool  10  with their x and y axes being parallel, respectively. During initial pixel capture, the first region  32 A monitored by the first sensor  26 A and the second region  32 B monitored by the second sensor  26 B are substantially similar in size and shape and can intersect, overlap and/or coincide for a majority of the respective regions  32 A,  32 B. Subsequently, the images (pixels) captured by the first sensor  26 A and the second sensor  26 B within the first region  32 A and the second region  32 B, respectively, can be cropped and upsampled as necessary in order to equalize and align the coverage of each sensor  26 A,  26 B in pixel space, i.e. to provide a common region  32 C (illustrated in  FIG.  1 C ). In order to achieve the sensing of the infrared reflective material from the wearable component  24 , the controller  28  can use the following algorithm: 
     
       
         
           
               
             
               
                   
               
             
            
               
                  sensing(IRCam, RGBCam){ 
               
               
                   sensed = matrix to hold sensed data 
               
               
                  nR = number of rows for both matrices 
               
               
                  nC = number of columns for both matrices 
               
               
                  for r= 0 to nR{ 
               
               
                   for c = 0 to nC 
               
               
                    if IRCam(r,c) is close to white and RGBCam(r,c) is close to black 
               
               
                     if (RGBCam(r,c)[0] + [1] + [2]) − (IRCam(r,c)[0] + [1] + [2]) 
               
               
                 is large ( &gt; 500) 
               
               
                      sensed(r,c) = white 
               
               
                     else sensed(r,c) = black 
               
               
                    else sensed(r,c) = black 
               
               
                   } 
               
               
                  } 
               
               
                  } 
               
               
                   
               
            
           
         
       
     
     For each pixel received by the first sensor  26 A (i.e. the RGB camera), if the red, green or blue values exist outside of the black family of colors (in one non-exclusive representative embodiment, R, G or B values no higher than 60 for any individual value and with a variance no higher than 30 for an 8-bit color value [0-255]), then the pixels are ignored. This eliminates colors other than black that may have change high enough between the two sensors  26 A,  26 B to pass the delta test. 
     Somewhat similarly, for each pixel received by the second sensor  26 B (i.e. the NoIR camera), if the red, green or blue values exist outside of the white family of colors (in one non-exclusive representative embodiment, R, G or B values no lower than 210 for any individual value and with a variance no higher than 40 for an 8-bit color value [0-255]), then the pixels are ignored. Again, this is done to lower false positives in the delta test. 
     Since some pixels may still be left with values that exist inside of the acceptable ranges for each sensor  26 A,  26 B that are not the intended material of the wearable component  24 , a pixel-for-pixel comparison can be made seeking a high delta value. More particularly, the algorithm seeks to find what areas of the captured images (pixels) have changed from pure black to pure white between the first sensor  26 A (e.g., the RGB camera) and the second sensor (e.g., the NoIR camera), while still accepting some color that may reflect off the material of the wearable component  24 . At this point, the noted areas are now defined as containing the wearable component  24  that includes and/or has been coated in, for example, the infrared reflective material. 
     Subsequently, to determine if a collision has occurred, i.e. to see if the wearable component  24  has actually extended to within the danger zone  34 , the following algorithm is utilized: 
     
       
         
           
               
               
               
             
               
                   
               
             
            
               
                   
                  bool collision(sensed, OR, OC, rad ){//danger zone OriginRow  
                   
               
               
                   
                 OriginColumn rad(ius) 
                   
               
               
                   
                  nR = number of rows for matrix 
                   
               
               
                   
                  nC = number of columns for matrix 
                   
               
               
                   
                  for r= 0 to nR{ 
                   
               
               
                   
                   for c = 0 to nC 
                   
               
               
                   
                    if sensed(r,c) is white 
                   
               
               
                   
                     if sqrt((r − OR){circumflex over ( )}2 + (c − OC){circumflex over ( )}2) &lt;= rad 
                   
               
               
                   
                      return true 
                   
               
               
                   
                   } 
                   
               
               
                   
                  } 
                   
               
               
                   
                  return false 
                   
               
               
                   
                  } 
               
               
                   
               
            
           
         
       
     
     Upon determination that the wearable component  24  has indeed entered into the predetermined danger zone  34 , then the controller  28  generates an appropriate signal to so indicate. Further, the controller  28  can then transmit the signal to the braking system  30  to activate the braking system  30 . 
     The braking system  30  is configured to selectively and rapidly stop movement of the moving component  16  of the power tool  10  upon receipt of a proper signal from the controller  28 . More particularly, with specific use of the safety system  12 , the braking system  30  is configured to selectively and rapidly stop movement of the moving component  16  of the power tool  10  upon receipt of a signal from the controller  28  that the wearable component  24  is within the predetermined danger zone  34  while the power tool  10  is running. 
     The braking system  30  can have any suitable design. Additionally, the safety system  12  can be configured such that the braking system  30  is effectively activated, i.e. by an appropriate signal from the controller  28 , and operated at any desired speed to inhibit injury to the user  20 . For example, in one non-exclusive embodiment, the braking system  30  can be effectively activated and operated at a reaction time braking speed of approximately 1.2 meters per second. Such a reaction time braking speed should be sufficient to inhibit injury to the user  20  in almost all working situations. Alternatively, the braking system  30  can be configured to be activated and operated at another suitable reaction time braking speed. 
     In summary, as measured from an origin of the predetermined danger zone  34 , if any pixel defined as representing the material of the wearable component  24  comes closer to the origin than the distance of a radius of the danger zone  34 , then it is determined by the controller  28 , i.e. through application of the algorithms noted above, that the wearable component  24  has entered the danger zone  34 . A signal, e.g., a GPIO signal, is then generated and sent, thus actuating the braking system  30 . 
     When the signal is transmitted to the braking system  30  so as to actuate the braking system  30 , the safety system  12 , i.e. the sensor assembly  26  and the controller  28 , is said to be working in collision detection mode. Additionally, as noted above, the safety system  12 , i.e. the sensor assembly  26  and the controller  28 , can also be used in the glove-sensing mode (or component-sensing mode). Stated in another manner, utilizing the sensing algorithm used for collision detection, the safety system  12  also is able to sense the presence of the wearable component  24  of the user  20  prior to the power tool  10  being switched on. As such, the safety system  12  requires the presence of the wearable component  24  on the focal plane before the power tool  10  can be energized. The wearable component  24  is considered present when their collection of grouped and sensed pixels (in no more or less than two groups) equates to an area predefined as the two-dimensional surface area of the wearable component  24  (as viewed from above) with hands flat on the focal plane. A GPIO controlled relay that allows current to reach the on/off switch  18  is then energized for a predetermined amount of time, during which time the power tool  10  can be turned on. If the predetermined time elapses prior to the power tool  10  being turned on, then the relay is de-energized and the safety system  12  waits for the wearable component  24  to be re-presented. In certain embodiments, at the motor, an additional relay is in place that is actuated by the motor current. The additional relay acts for sensing of a running condition on the power tool  10 . This additional relay allows the SBC of the controller  28  to seamlessly swap between the glove-sensing mode and the collision detection mode. 
     Thus, in certain embodiments, the power tool  10  is only startable, e.g., via the on/off switch  18 , once the user  20  introduces the wearable component  24  within the region that is monitored and/or sensed by the sensor assembly  26 . At such time, the controller  28  is considered to be in the “glove-sensing mode”. Alternatively, in other embodiments, the power tool  10  can be started by the user  20  without the need to initially introduce the wearable component  24  within the region that is monitored and/or sensed by the sensor assembly  26 . 
       FIG.  1 B  is a simplified schematic side view illustration of the power tool  10 , and the portion of the power tool safety system  12  illustrated in  FIG.  1 A . More specifically,  FIG.  1 B  provides another view of the power tool  10  and the safety system  12  of the present invention, and the operational features and components thereof. For example,  FIG.  1 B  again illustrates the base  14  and the moving component  16  of the power tool  10 , and the sensor assembly  26  (illustrated in phantom), the controller  28  (illustrated in phantom) and the braking system  30  (illustrated in phantom) of the safety system  12 . 
       FIGS.  1 C and  1 D  more clearly illustrate the regions  32 A,  32 B that are captured by the first sensor  26 A (illustrated in  FIG.  1 A ) and the second sensor  26 B (illustrated in  FIG.  1 A ), respectively, and the determination of the danger zone  34  in the area near to, adjacent to, and/or that substantially encircles the moving component  16  of the power tool  10 . In particular,  FIG.  1 C  is a simplified schematic top view illustration of a portion of the power tool  10  and the power tool safety system  12  illustrated in  FIG.  1 A . It is appreciated that certain portions of the power tool  10  and certain portions of the safety system  12  have not been illustrated in  FIG.  1 C  for purposes of clarity. Additionally,  FIG.  1 D  is a simplified schematic top view illustration of a portion of the user  20 , i.e. the hand of the user  20 , and a portion of the power tool  10  and the power tool safety system  12  illustrated in  FIG.  1 A . It is again appreciated that certain portions of the power tool  10  and certain portions of the safety system  12  have not been illustrated in  FIG.  1 D  for purposes of clarity. 
     As shown in  FIG.  1 C , the first sensor  26 A is configured to monitor the first region  32 A, e.g., to capture images (pixels) within the first region  32 A, and the second sensor  26 B is configured to monitor the second region  32 B, e.g., to capture images (pixels) within the second region  32 B. For simplicity, the first region  32 A and the second region  32 B are illustrated in  FIG.  1 C  as being substantially rectangular in shape. However, it is appreciated that in certain alternative embodiments, the first region  32 A and/or the second region  32 B can be other than substantially rectangular-shaped. For example, in some non-exclusive alternative embodiments, one or both of the regions  32 A,  32 B can be substantially circle-shaped, oval-shaped, or some other shape. 
     Additionally,  FIG.  1 C  further illustrates that the intersection and/or overlap between the first region  32 A and the second region  32 B, e.g., along the work surface on the base  14  of the power tool  10 , defines a common region  32 C that is further utilized for defining the predetermined danger zone  34  (illustrated in  FIG.  1 D ) that is positioned near to, adjacent to, and/or substantially encircles the moving component  16  of the power tool  10 . Stated in another manner, the predetermined danger zone  34  can be based on the common region  32 C. More specifically, in one embodiment, as shown in  FIG.  1 D , the danger zone  34  can be defined and/or predetermined by extending a radius in all directions from an origin within the common region  32 C. Alternatively, the danger zone  34  can be predetermined within the common region  32 C in a somewhat different manner. 
     Further, as noted above,  FIG.  1 D  also shows the user  20 , i.e. the hand  20 A of the user  20 , with the wearable component  24  positioned thereon. As shown, the wearable component  24  has just extended within the predetermined danger zone  34 , and thus should be readily detectable by the safety system  12 , i.e. by the sensor assembly  26  and the controller  28 . 
       FIG.  2    is a simplified schematic top view illustration of a portion of the user  20 , i.e. the hand  20 A of the user  20 , a portion of the power tool  10 , and a portion of another embodiment of the power tool safety system  212 . It is appreciated that certain portions of the power tool  10  and certain portions of the safety system  212  have not been illustrated in  FIG.  2    for purposes of clarity. 
     As shown in  FIG.  2   , the power tool  10  is again a band saw, although it is appreciated that the power tool  10  can be any suitable power tool that is usable with the safety system  212 . More specifically,  FIG.  2    again illustrates at least the base  14  and the moving component  16  of the power tool  10 . 
     Additionally, the safety system  212  is substantially similar to the safety system  12  that was illustrated and described herein above. For example, the safety system again includes the sensor assembly (not shown in  FIG.  2   ), the controller  228 , and the braking system (not shown in  FIG.  2   ) that are substantially similar in overall design and function to what was illustrated and described above. However, the wearable component  224  that is utilized in the embodiment shown in  FIG.  2    is somewhat different in design as compared to the previous embodiment. In particular, in this embodiment, the wearable component  224  is configured to only cover one finger-tip  20 B on the hand  20 A of the user  20 , rather than having a glove-like design that covers the entire hand  20 A of the user  20 . Further, the wearable component  224  is again made from and/or includes material that can be sensed by the sensors  26 A,  26 B (illustrated, for example, in  FIG.  1 A ) of the sensor assembly for purposes of identifying when the wearable component  224  (and thus at least a portion of the hand  20 A of the user  20 ) enters the danger zone  234  near, adjacent to and/or that substantially encircles the moving component  16  of the power tool  10  during use of the power tool  10 . 
       FIGS.  3  and  4    are flowcharts showing representative examples of use of the power tool in conjunction with the power tool safety system. It is understood that the representative examples disclosed herein can include greater or fewer steps than those shown and described relative to  FIGS.  3  and  4   . Stated another way, the representative examples described in accordance with the present invention can omit one or more steps illustrated in  FIGS.  3  and  4   , or can add additional steps not shown and described in  FIGS.  3  and  4   , and still fall within the purview of the present invention. Further, the sequence of the steps can be varied from those shown and described relative to  FIGS.  3  and  4   . Thus, it is appreciated that the specific sequence of steps illustrated in  FIGS.  3  and  4    is not intended to limit the sequencing of steps in any manner. 
     Referring initially to  FIG.  3   ,  FIG.  3    is a flowchart illustrating a representative example of a use of the power tool in conjunction with the power tool safety system. In particular,  FIG.  3    illustrates an example of a use of the power tool where the sensor assembly and/or the controller does not sense the presence of the wearable component within the danger zone that surrounds the moving component of the power tool. 
     At step  301 , a user gathers materials to be used during use of the power tool, e.g., the materials to be modified, such as pieces of wood to be cut, during use of the power tool, and makes adjustments to the settings of the power tool as necessary for typical and/or desired use of the power tool. 
     At step  303 , the user pulls the safety cutoff switch on the power tool, thereby energizing the power tool and the controller. At such time, in certain embodiments, the controller, i.e. the single board computer (SBC), enters into a glove-sensing mode. 
     At step  305 , the user puts on the wearable component, e.g., the glove, and then presents the wearable component on the work surface of the power tool such that the wearable component is sensed by the sensor assembly. 
     At step  307 , based on the sensing of the wearable component on the work surface, the on switch relay for the power tool is energized. 
     At step  309 , the user presses the on/off (start) button and the power tool begins to run. 
     At step  311 , with the start-up of the power tool, the controller, i.e. the SBC, changes into collision detection mode (at run time). 
     At step  313 , the user then passes the materials to be modified, e.g., the pieces of wood to be cut, to the power tool in a typical manner. 
     At step  315 , the user presses the on/off (stop) button on the power tool to stop the running of the power tool. At this point, the power tool allows the user to turn the power tool back on for a predetermined period of time (at which point the controller, i.e. the SBC, would return to the glove-sensing mode). However, it is also appreciated that upon pressing of the on/off button, the collision detection mode may continue to run for a specified period of time to account for machine slow down and stop time. 
     At step  317 , the user presses the safety cutoff switch and the power tool and the safety system are de-energized. 
       FIG.  4    is a flowchart illustrating another representative example of a use of the power tool that is used in conjunction with the power tool safety system. In particular,  FIG.  4    illustrates an example of a use of the power tool where the sensor assembly and/or the controller does sense the presence of the wearable component within the danger zone that surrounds the moving component of the power tool. 
     At step  401 , a user gathers materials to be used during use of the power tool, e.g., the materials to be modified, such as pieces of wood to be cut, during use of the power tool, and makes adjustments to the settings of the power tool as necessary for typical and/or desired use of the power tool. 
     At step  403 , the user pulls the safety cutoff switch on the power tool, thereby energizing the power tool and the controller. At such time, in certain embodiments, the controller, i.e. the single board computer (SBC), enters into a glove-sensing mode. 
     At step  405 , the user puts on the wearable component, e.g., the glove, and then presents the wearable component on the work surface of the power tool such that the wearable component is sensed by the sensor assembly. 
     At step  407 , based on the sensing of the wearable component on the work surface, the on switch relay for the power tool is energized. 
     At step  409 , the user presses the on/off (start) button and the power tool begins to run. 
     At step  411 , with the start-up of the power tool, the controller, i.e. the SBC, changes into collision detection mode (at run time). 
     At step  413 , the user then passes the materials to be modified, e.g., the pieces of wood to be cut, to the power tool in a typical manner. 
     At step  415 , while the user is passing the materials to be modified to the power tool, the wearable component that is being worn by the user passes into the danger zone surrounding the moving component of the power tool. 
     At step  417 , the sensor assembly and the controller sense the presence of the wearable component in the danger zone surrounding the moving component of the power tool, and a signal is generated and transmitted to the braking system such that the braking system is engaged to rapidly stop movement of the moving component relative to the base of the power tool, and power to the motor of the power tool is cut. 
     At step  419 , the movement of the moving component relative to the base of the power tool is arrested prior to contact between the wearable component and the moving component. 
     At step  421 , the user re-presents the wearable component on the work surface of the power tool such that the wearable component is sensed by the sensor assembly, and the on switch relay for the power tool is again energized. 
     At step  423 , the user continues to pass the materials to be modified, e.g., the pieces of wood to be cut, to the power tool in a typical manner. 
     At step  425 , the user presses the on/off (stop) button on the power tool to stop the running of the power tool. At this point, the power tool allows the user to turn the power tool back on for a predetermined period of time (at which point the controller, i.e. the SBC, would return to the glove-sensing mode). However, it is also appreciated that upon pressing of the on/off button, the collision detection mode may continue to run for a specified period of time to account for machine slow down and stop time. 
     At step  427 , the user presses the safety cutoff switch and the power tool and the safety system are de-energized. 
     In summary, the safety system  12  of the present invention, as described in detail herein, is designed to arrest the motion of a moving component  16  on a power tool  10 , e.g., a blade on a cutting tool, prior to contact with the user  20 . For example, in various embodiments, utilizing a single board computer (SBC) and a red green blue (RGB) input device and no infrared filter (NoIR) input device pair, the motion of a wearable component  24  coated in black infrared only reflective material can be sensed within a predetermined danger zone  34  near, adjacent to and/or substantially encircling the moving component  16 . Upon sensing the infrared reflective material of the wearable component  24  having entered into the danger zone  34 , a GPIO signal is sent to a relay that actuates a push/pull solenoid; thus engaging a mechanical braking system  30  to rapidly stop movement of the moving component  16 . 
     Additionally, as provided herein, the safety system  12  of the present invention provides various unique features applicable during operation of the power tool  10  with which the safety system  12  is being used. For example, in certain embodiments, the safety system  12  provides features such as (i) utilizing a camera array, biased by infrared filtering, to detect an infrared only reflective material or pigment; (ii) utilizing the large change in color (as opposed to the existence of color) at a moment in time to distinguish the item of interest, e.g., the wearable component  24  and/or at least a portion of the hand  20 A of the user  20 ; (iii) utilizing a synchronized camera array to detect presence of the user  20 , e.g., via the wearable component  24 , within a danger zone  34 , and thus signaling for activation of the braking system  30  to stop movement of the moving component  16  of the power tool  10 ; (iv) utilizing an infrared only reflective pigment coated wearable component  24  to identify the presence in the user  20  in the work area and the danger zone  34  around the moving component  16 ; and (v) forcing the user  20  to present the wearable component  24  on the work surface of the power tool  10  as proof of presence of the user  20  or wearable component  24  before the power tool  10  can be switched to the operating (running) condition. 
     Further, as noted above, in certain embodiments of the present invention, the safety system need not include the wearable component. For example,  FIG.  5 A  is a simplified schematic front view illustration of the power tool  10 , and a portion of still another embodiment of the power tool safety system  512 . Additionally,  FIG.  5 B  is a simplified schematic top view illustration of a portion of the user  20 , i.e. a hand  20 A of the user  20 , a portion of the power tool  10 , and a portion of the power tool safety system  512  illustrated in  FIG.  5 A . It is appreciated that certain portions of the power tool  10  and certain portions of the safety system  512  have not been illustrated in  FIG.  5 A  and/or  FIG.  5 B  for purposes of clarity. 
     As above, the power tool  10  can again be a band saw, a table saw, a circular saw, a miter saw, a drill press, or any other suitable power tool. Additionally, as with the previous embodiments, the power tool  10  includes the base  14  and the moving component  16 , e.g., a saw blade or a drill bit, that is movable relative to the base  14 . Further, the power tool  10  can also include an on/off (power) switch  18  and a safety cutoff switch  22  that are substantially identical in design and function as described in greater detail herein above. 
     Additionally, as illustrated in  FIGS.  5 A and  5 B , the safety system  512  is somewhat similar to the previous embodiments, but does not include the wearable component that was included within the previous embodiments. More specifically, as illustrated in this embodiment, the safety system  512  can be configured to include one or more of a sensor assembly  526 , a controller  528  and a braking system  530 . 
     Referring initially to  FIG.  5 A , as with the previous embodiments, the sensor assembly  526  is configured to sense and/or detect the presence of at least a portion of a hand  20 A of the user  20  in a position near and/or adjacent to the moving component  16  of the power tool  10 . The design of the sensor assembly  526  can be varied to suit the requirements of the safety system  512 . In this embodiment, as shown in  FIG.  5 A , the sensor assembly  526  includes a first sensor  526 A and a second sensor  526 B. Alternatively, in other embodiments, the sensor assembly  526  can include only a single sensor, or the sensor assembly  526  can be configured to use greater than two sensors. 
     During use of the safety system  512 , the first sensor  526 A is configured to function as a training sensor that is utilized to capture at least one hand image, and preferably a plurality of hand images (pixels). More particularly, as provided herein, the hand images as captured by the first sensor  526 A are subsequently used for training purposes, i.e. to build a model of the hand and/or to train the controller  528  to recognize the presence of a hand  20 A within a particular region. It is appreciated that the model of the hand can also be referred to as and/or function as at least a portion of a detection algorithm that is usable within the controller  528  Alternatively, it is appreciated that in certain embodiments, the safety system  512  and/or the sensor assembly  526  need not include the first sensor  526 A, and suitable hand images gathered from any suitable source may be provided to the controller  528 , i.e. to build a model of the hand  20 A (a detection algorithm) and/or to train the controller  528  to recognize the presence of a hand  20 A within a particular region. 
     In some embodiments, as shown in  FIG.  5 A , the first sensor  526 A can be positioned spaced apart from the power tool  10  and can function independently of the power tool  10  when being used to capture hand images to build the virtual model of the hand and/or to generate the desired detection algorithm. Alternatively, in other embodiments, the first sensor  526 A can be coupled to the power tool  10 . 
     During capture of the hand images, e.g., with the first sensor  526 A, it is desired to capture as many hand images as deemed necessary to effectively represent a broad spectrum of potential hand positions, shapes, colors and sizes. For example, in various applications, it can be desired to capture sufficient hand images to be able to effectively identify key points on hands such as joint locations, finger-tips, palm markers, and/or other identifiable key points. With the effective capture of sufficient hand images to identify such key points on the hand, a model of the hand (detection algorithm) can be effectively built which is subsequently usable to identify the presence of a hand within a particular region, i.e. based on comparison of images captured within the region with the hand images used to build the model and/or the model of the hand (detection algorithm) itself. Additionally, it is appreciated that such key points on the hands can be predicted and retrained as necessary to increase the accuracy of the model (detection algorithm). Once the model has been effectively built, the model (detection algorithm) can be loaded into the controller  528  for use during hand detection applications associated with use of the safety system  512  while the power tool  10  is in use. More particularly, as described in greater detail herein below, during run time of the power tool  10 , the controller  528  can utilize the uploaded model (detection algorithm) to predict if and where key points of a hand  20 A are present within a predetermined danger zone  534  (illustrated in  FIG.  5 B ). Stated in another manner, if key points of a hand  20 A are found in images within a region, e.g., within a region  532  (illustrated in  FIG.  5 B ) of the second sensor  526 B, they are analyzed with the controller  528  in collision detection mode to determine if the key points, or significant areas between them, have entered into the predetermined danger zone  534 . 
     In certain applications, the hand(s) utilized for capturing hand images with the first sensor  526 A for building the model can be a representative hand  520 A of a representative user  520  of the power tool  10 , and/or the hand can be the hand of one or more other suitable persons. Additionally, in various applications, it is desired to utilize hand images of hands of various shapes, sizes and colors, so that the model (detection algorithm) is usable to effectively detect the presence of a hand  20 A of any user  20  of the power tool  10 . Alternatively, in other applications, it is appreciated that any suitable hand images can be utilized. 
     In summary, in certain embodiments, the first sensor  526 A can be configured to operate within a neural network that is trained with a significant number of hand images representing a broad spectrum of hand positions, shapes, colors and sizes. With such design, the first sensor  526 A can be utilized capture various hand images that are sufficient to build a comprehensive model of the hand, i.e. a comprehensive detection algorithm. 
     As shown, in various embodiments, the second sensor  526 B can be coupled to the power tool  10  and can be positioned and oriented to monitor a region  532  near, adjacent to and/or that substantially encircles the moving component  16  of the power tool  10 . For simplicity, the region  532  is illustrated in  FIG.  5 B  as being substantially rectangular in shape. However, it is appreciated that in certain alternative embodiments, the region  532  can be other than substantially rectangular-shaped. For example, in some non-exclusive alternative embodiments, the region  532  can be substantially circle-shaped, oval-shaped, or some other shape. 
     Additionally, as above, the region  532  can then be utilized for defining the predetermined danger zone  534  that is positioned near to, adjacent to, and/or substantially encircles the moving component  16  of the power tool  10 . Stated in another manner, the predetermined danger zone  534  can be based on the region  532 . More specifically, in one embodiment, the danger zone  534  can be defined and/or predetermined by extending a radius in all directions from an origin within the region  532 . Alternatively, the danger zone  534  can be predetermined within the region  532  in a somewhat different manner. However defined, the predetermined danger zone  534  is then utilized for purposes of determining if and when at least a portion of the hand  20 A of the user  20  has entered into the danger zone  534 . As such, the safety system  512 , i.e. the sensor assembly  526  and/or the controller  528 , can be said to be configured to monitor the predetermined danger zone  534  that is positioned near to, adjacent to, and/or substantially encircles the moving component  16  of the power tool  10 . 
     It is appreciated that in certain embodiments, the second sensor  526 B can also be used and/or function as the training sensor that captures the initial hand images that are used for building the model of the hand. As such, some embodiments can be designed without the specific need for the first sensor  526 A as described herein, and the sensor assembly  526  may only include a single sensor, i.e. the second sensor  526 B. Thus, in such embodiments, the second sensor  526 B may be described as and/or can function as both the first sensor and the second sensor. 
     The design of the first sensor  526 A and the second sensor  526 B can be varied. For example, in certain embodiments, each of the first sensor  526 A and the second sensor  526 B can be a red blue green (RBG) input device, e.g., camera or other suitable input device, such as described above. More specifically, in such embodiments, the first sensor  526 A can be a red blue green (RBG) input device that is used to capture various hand images for building a virtual model of the hand; and the second sensor  526 B can be a red blue green (RBG) input device that is used to monitor the region  532  that is positioned near to, adjacent to, and/or substantially encircles the moving component  16  of the power tool  10 . Alternatively, one or both of the first sensor  526 A and the second sensor  526 B can have another suitable design. 
     As above, the use of the terms “first sensor” and “second sensor” is merely for convenience and ease of illustration, and either sensor  526 A,  526 B can be referred to as the “first sensor” and/or the “second sensor”. 
     In certain embodiments, the controller  528  can be coupled to the power tool  10 , i.e. to the base  14  of the power tool  10 . Alternatively, the controller  528  can be provided remotely from the power tool  10 . 
     In the embodiment illustrated in  FIGS.  5 A and  5 B , the controller  528  is configured to receive and analyze input (data) from the sensor assembly  526 , i.e. the hand images (pixels) captured by the first sensor  526 A that are used to build the virtual model of the hand, and the data generated by (e.g., images captured by) the second sensor  526 B to determine when at least a portion of the hand  20 A is within the predetermined danger zone  534  that is defined near to, adjacent to, and/or substantially encircling the moving component  16  of the power tool  10 . Stated in another manner, the hand images, i.e. as captured by the first sensor  526 A or otherwise provided to the controller  528 , are utilized to generate a model of the hand including at least one key point, and preferably a plurality of key points of the hand. Such model is then usable by the controller  528  to determine whether a hand  20 A of a user  20  has entered into the predetermined danger zone  534 , e.g., by analyzing images of the region  532  as captured by the second sensor  526 B. 
     As above, the controller  528  and the circuitry provided therewith can have any suitable design. For example, in some embodiments, the controller  528  includes a single board computer (SBC) having one or more processors or circuits for purposes of analyzing the data generated by (e.g., images captured by) the first sensor  526 A and/or the second sensor  526 B. 
     Additionally, in certain embodiments, the controller  528  can incorporate one more visual outputs, e.g., LED lights, that alert the user  20  regarding the status of the power tool  10  and/or the safety system  512 . For example, in such embodiments, the controller  528  can include visual outputs indicative that the power tool  10  is in a no start (non-operating) condition, a can start condition, and a running (operating) condition; as well as a visual output regarding activation of the safety system  512 , i.e. identifying a collision detection when at least a portion of the hand  20 A is determined to be within the danger zone  534 . 
     Further, the controller  528  can incorporate the use of any system of electrical connections, e.g., relays, General Purpose Input/Output (GPIO) connections, etc., for purposes of electrically connecting the controller  528  with the sensor assembly  526  and the braking system  530 , as well as electrically connecting various components within the controller  528 . 
     Further, as noted above,  FIG.  5 B  also shows the user  20 , i.e. the hand  20 A of the user  20 , having just extended within the predetermined danger zone  534 . Thus, the hand  20 A of the user  20  should be readily detectable by the safety system  512 , i.e. by the sensor assembly  526  and the controller  528 . 
     As above, if a collision to the danger zone  534  is detected, i.e. if at least a portion of the hand  20 A is detected within the danger zone  534 , a signal is sent from the controller  528  to engage the braking system  530  to rapidly arrest the motion of the moving component  16  of the power tool  10 . Conversely, if a collision to the danger zone  534  is not detected, i.e. if at least a portion of the hand  20 A is not detected within the danger zone  534 , the power tool  10  and the safety system  512  continue normal operation without generating a signal to activate the braking system  530 . 
     During use of the power tool  10  with such safety system  512  as illustrated and described herein, the following steps can occur: (i) the user  20  turns on the controller  528 , i.e. the SBC, by pulling the safety cutoff switch  22  on the power tool; (ii) the controller  528  loads (with the model of the hand  20 A as generated) and begins to search for hands within the region  532  of the second sensor  526 B that is mounted above the work surface, i.e. the base  14  of the power tool  10 ; (iii) the user  20  turns the power tool  10  on (e.g., selectively activates the blade of the band saw); (iv) active collision detection begins; (v) the user  20  presents materials to the work surface, e.g., wood to be cut with the moving component  16 , or blade, of the band saw  10 ; (vi) the hand  20 A of the user  20  may enter the work surface at any point in the above process, and if the hand  20 A of the user  20  enters the danger zone  534 , the controller  528  generates a signal that is sent to the braking system  530  to shut down or arrest the motion of the power tool  10 , but if the hand  20 A of the user  20  remains outside of the danger zone  534  (i.e. is not detected within the danger zone  534 ), operation of the power tool  10  continues as normal; (vii) the user  20  then shuts off the power tool  10  (as above, it is appreciated that collision detection may continue to run for a specified period of time to account for slow down and stop time of the power tool  10 ); and (viii) the user  20  shuts off the safety cutoff switch  22 , and in turn the controller  528  and collision detection are turned off. 
     In summary, in the embodiment shown in  FIGS.  5 A and  5 B , the safety system  512  includes a neural network that is trained with a significant number of hand images representing a broad spectrum of hand positions, shapes, colors and sizes in order to generate a virtual model of the hand (i.e. a detection algorithm) that is utilized to determine at least one, and preferably multiple key points on the hand  20 A. The hand model is then rendered in the region  532  of the second sensor  526 B and utilized in a collision detection mode to determine if a hand  20 A has entered into the predetermined danger zone  534 . 
     It is appreciated that for proper use of this embodiment of the safety system  512 , certain factors must be complied with: (i) Training of the detection system must occur prior to run time. In other words, the unit is fully trained and retrained prior to installation onto the controller  528  (SBC); (ii) Once on the controller  528  (SBC), the detection model should not change by retraining as this may lead to a drop in accuracy. In other words, the unit never retrains only on the specific hands of a user; (iii) During initial training of the model, key points may be found in error of actual key point locations. These key points can be manually corrected and the prediction model rerun until a significantly accurate detection platform is achieved; and (iv) As provided herein, in this embodiment, a glove or other wearable component is not required to train or detect a hand; however it may be used to reduce the amount of training that the system requires. For example, if a gloved hand is the sole method of training, the glove will then be required for detection. It is appreciated that this decision, i.e. whether the unit is to be trained on a gloved hand or a non-gloved hand, will have to be made prior to beginning programming of the unit. 
     It is understood that although a number of different embodiments of the power tool safety system have been illustrated and described herein, one or more features of any one embodiment can be combined with one or more features of one or more of the other embodiments, provided that such combination satisfies the intent of the present invention. 
     While a number of exemplary aspects and embodiments of the power tool safety system have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.