Abstract:
A scale provides a user with a display of a nutritional parameter on the basis of the weight of the food being weighed. The values for a plurality of food items can be accumulated and a single nutritional parameter characterizing a complete meal or recipe may be displayed.

Description:
[0001]    This application claims priority under 35 U.S.C. §§119 and/or 365 to United Kingdom Patent Application No. 0229467.6 filed in Great Britain on Dec. 18, 2002; the entire content of which is hereby incorporated by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to scales which display nutritional information. 
       BACKGROUND TO THE INVENTION 
       [0003]    British Patent GB-A-2133166 discloses an electronic scale which is provided with means to enable a user to identify food being weighed. This information is then used, together with a weight value, to generate a value for the caloric value of the food being weighed. However, the scale proposed in GB-A-2133166 is only capable of providing a caloric value for one food item at a time. In contrast, most meals and recipes consist of a combination of ingredients, for example, a meal of roast chicken, peas and boiled potatoes or a cake recipe. 
         [0004]    U.S. Pat. Nos. 6,040,531 and 6,436,036 disclose devices and methods for calculating and tallying single-valued nutritional indicators for known quantities of various foodstuffs. The single-valued nutritional indicator (such as those expressed in terms of POINTS®) may take into account multiple nutritional properties such as caloric content, fat content and fiber content. However, the devices of these patents have no mechanism for determining the single-valued nutritional indicators for unknown quantities of a foodstuff or combinations of foodstuffs such as might, for example, be spooned out on a serving plate for an evening meal. 
       SUMMARY OF THE PREFERRED EMBODIMENTS 
       [0005]    It is an aim of the present invention to provide a scale which is of enhanced utility to those for whom the nutritional parameters of their food are important. Preferred embodiments of the present invention provide single-valued nutritional indicators for a weighed foodstuff or combinations of foodstuffs, the total single-valued nutritional indicator taking into account multiple nutritional attributes of the foodstuffs. 
         [0006]    According to the present invention, there is provided a scale comprising 
         [0007]    a weight sensor; 
         [0008]    a database memory storing a database of specific nutritional parameter values for a plurality of foodstuffs; 
         [0009]    a display system such as a keypad or touch screen; 
         [0010]    user input system; and 
         [0011]    a processor configured to be responsive to operations of the user input system to select data from the memory and generate respective absolute nutritional parameter values or single-valued nutritional indicators in dependence on the output of the weight sensor and the data. In preferred embodiments, a single-valued nutritional indicator per unit weight is stored in a look-up table in the database memory for various common food stuffs. 
         [0012]    In preferred embodiments the processor is configured for accumulating a plurality of single-valued nutritional indicators, generated in response to a plurality of user input operations using the user input system, and controlling the display to display the resultant total accumulated single-valued nutritional indicator for foods assembled on the scale. 
         [0013]    The terms “specific” and “absolute” as used herein mean “per unit” and “total”. 
         [0014]    The weight sensor could be of any type that gives an output received by the processor, for example an electronic load cell. 
         [0015]    The term “database” is used only to indicate a source of organized data and may be as simple as a lookup table or list of per unit weight values. Alternatively, the database may contain underlying nutritional data such as caloric content per unit weight, fat per unit weight etc. from which a single-valued nutritional indicator can be calculated. 
         [0016]    The processor preferably comprises a microprocessor or a microcontroller. However, an ASIC could be employed. 
         [0017]    The user input system preferably comprises a keypad. However, it could comprise a touch sensitive display or a display in association with a pointing device, such as a mouse or tracker ball. 
         [0018]    Preferably, the processor is configured to be responsive to a user input operation, using the user input system, to store a generated absolute nutritional parameter value in a writable memory, e.g. RAM, and to include absolute nutritional parameter values stored in the writable memory in said accumulated nutritional parameter value. The writable memory may comprises one or more discrete devices or be integrated into a processor, such as a microcontroller. 
         [0019]    Preferably, the processor means is configured for storing a foodstuff identifier in the writable memory in association with each generated absolute nutritional parameter value stored therein. More preferably, the processing means is configured to be responsive to a user input operation, using the user input means, to read a foodstuff identifier and an absolute nutritional parameter value from the writable memory and control the display to display an indication of the foodstuff identified by said identifier and the associated absolute nutritional parameter value. The foodstuff identifier stored in the writable memory need not be the actual name of the foodstuff and the indication displayed could be selected from a list of foodstuff names on the basis of the identifier. Still more preferably, the processor is configured to be responsive to a user input operation, using the user input system, while said indication and associated nutritional parameter are being displayed, to update the corresponding nutritional parameter value in the writable memory in dependence on the output of the weight sensor. 
         [0020]    Preferably, the processor means is configured to be responsive to a user input operation, using the user input system, to read a foodstuff identifier from database memory and control the display to display the name of the foodstuff identified by said identifier. More preferably, the processing means is configured to be responsive to user input operations, using the user input means, to read foodstuff identifiers sequentially from database memory and control the display to display in sequence the name of each foodstuff identified by one of said identifiers. Thus, the user can scroll through the stored items. Still more preferably, the user input system includes character input means and the processor means is configured to be responsive to user input operations, using character user means, of a sequence of characters to select read a foodstuff identifier from the database memory for which the start of the name of the foodstuff corresponds to the input character sequence. 
         [0021]    The nutritional parameter or single-valued nutritional indicator for a foodstuff may be defined by algorithms such as disclosed in U.S. Pat. Nos. 6,040,531 and 6,436,036 to Miller-Kovach et al., the contents of which are hereby incorporated by reference herein in their entirety. In one embodiment single-valued nutritional indicators may be determined and tallied in terms of “POINTS®.” POINTS® is a registered trademark of Weight Watchers International. One such algorithm is: 
         [0000]    
       
         
           
             p 
             = 
             
               
                 c 
                 
                   k 
                   1 
                 
               
               + 
               
                 f 
                 
                   k 
                   2 
                 
               
             
           
         
       
     
         [0000]    where c is the calorific value of the foodstuff in kilocalories per gram, f is the total fat content of the food stuff per gram in grams, k 1  is constant, preferably about 70, k 2  is in the range k 1 /35 to k 1 /10, preferably k 1 /17.5. 
         [0022]    Alternatively, the specific nutritional parameter for a foodstuff may be defined by: 
         [0000]    
       
         
           
             p 
             = 
             
               
                 c 
                 
                   k 
                   1 
                 
               
               + 
               
                 f 
                 
                   k 
                   2 
                 
               
               - 
               
                 r 
                 
                   k 
                   3 
                 
               
             
           
         
       
     
         [0000]    where c is the calorific value of the foodstuff in kilocalories per gram, f is the total fat content of the food stuff per gram in grams, r is the dietary fiber content of the foodstuff in grams per gram, k 1  is constant, preferably about 50, k 2  is in the range k 1 /3 to k 1 /5, preferably k 1 /4, and k 3  is in the range k 1 /20 to k 1 /5, preferably k 1 /10. 
         [0023]    The present invention also relates to methods for providing a total, single-valued nutritional indicator for a food serving or recipe containing plural foodstuffs using a scale with a weight sensor, database user input, processor and display. In accordance with such methods the following steps may be performed: 
         [0024]    (a) placing a food vessel on the scale; 
         [0025]    (b) zeroing the weight reading of the weight sensor; 
         [0026]    (c) placing a foodstuff in the vessel; 
         [0027]    (d) entering an identification of the foodstuff using the user input; 
         [0028]    (e) employing the processor and database to provide a selected nutritional indicator per unit weight of the identified foodstuff and calculating a single-valued nutritional indicator for the weight of the identified foodstuff sensed by the weight sensor; 
         [0029]    (f) repeating steps (b)-(e) at least once; 
         [0030]    (g) calculating a total single-valued nutritional indicator for the foodstuffs in the vessel; 
         [0031]    (h) displaying the total, single-valued nutritional indicator for the foodstuffs in the vessel. 
         [0032]    The method may also include the step of displaying a current total, single-valued nutritional indicator for the foodstuffs in the vessel after each foodstuff is added to the vessel. The indicator may advantageously may be displayed to an accuracy of one decimal place or more. 
         [0033]    The foregoing is intended as a convenient summary of preferred embodiments of the present invention. The scope of the invention is, however, determined by the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]      FIGS. 1(   a ) and  1 ( b ) are perspective views of two scale embodiments according to the present invention; 
           [0035]      FIG. 2  is a block diagram of an embodiment of the electronics of the scales of  FIG. 1 ; and 
           [0036]      FIG. 3  is a state diagram illustrating the operation of the scales of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0037]    Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings. 
         [0038]    Referring to  FIG. 1(   a ), a scale  1  comprises a body  2  and a pan  3  supported on a load cell  12  ( FIG. 2)  within the body  2  by a coupling member passing through the top of the body. The body  2  has a sloping front face which contains an LCD (liquid crystal display)  4  and a keypad  5 . In addition to the load cell, the body  2  houses microcomputer circuitry. 
         [0039]    Referring to  FIG. 1(   b ), a scale  101  comprises a body  102  and a platen  103  supported on a load cell  12  ( FIG. 2)  within the body  102  by a coupling member passing through the top of the body. The body  102  has a face which carries an LCD (liquid crystal display)  4  and a keypad  5 . In addition to the load cell, the body  102  houses microcomputer circuitry. 
         [0040]    The platen  103  is adapted for receiving a food vessel  104  such as a dinner plate or a mixing bowl as shown in  FIG. 1(   b ). In operation the vessel  104  may be placed on the platen  103  and the scale zeroed by pressing the “ON/ZERO” button on the keypad. The display then registers a weight of “0” grams or ounces. A recipe ingredient such as cheese may then be added to the vessel and only its weight will be registered. The user may then identify the foodstuff using alphanumeric keys on the keypad. The processor selects a per unit weight value appropriate for the identified foodstuff and calculates a single-valued nutritional indicator such as the POINTS® value for the weight of the foodstuff placed in the vessel. As shown in  FIG. 1(   b ), for example, the foodstuff is identified as “CHEDDAR CHEESE,” its weight is displayed as “100 grams” and its POINTS® value displayed as “6.0.” The scale may be again zeroed and a second foodstuff placed in the vessel with the cheese. The foodstuff may be identified by the user and a total POINTS® value for the cheese and the second foodstuff calculated and displayed. In this manner the scale may be operated in an “add and weigh” mode to add a particular weight or point value of each ingredient, and to assemble all of the ingredients in the vessel and display a total POINTS® value for the assembled ingredients. 
         [0041]    In a similar fashion, a dinner plate may be used as the vessel, and a dinner serving of various foodstuffs assembled while keeping a running total of the POINTS® value for the various foods being assembled on the plate. 
         [0042]    Referring to  FIG. 2 , the circuitry of the scale is based around a microcontroller  11  which includes a keypad interface  11   a , an analog-to-digital converter  11   b , an LCD interface  11   c , a data/address bus interface  11   d  and internal RAM  11   e . The keypad interface  11   a  is connected to the keys  5  and the LCD interface  11   c  is connected to the LCD  4 . The output of the load cell  12  is connected to the analog-to-digital converter  11   b . A ROM  13  is connected to the data/address bus  11   d  by a data/address bus  14 . 
         [0043]    The ROM is programmed with a database of food types and associated specific, i.e. per unit weight, nutritional parameter values. In the present embodiment, the specific nutritional parameter values may be POINTS® per gram where a POINTS® value p for a food item is defined by: 
         [0000]    
       
         
           
             p 
             = 
             
               
                 c 
                 
                   k 
                   1 
                 
               
               + 
               
                 f 
                 
                   k 
                   2 
                 
               
             
           
         
       
     
         [0000]    where c is the calorific value of the food item in kilocalories, f is the saturated fat content in grams, k 1  is a 70 and k 2  is 4. 
         [0044]    The keypad  5  may comprise an ON key  5   a , an ABC key  5   b , a DEF key  5   c , a GHI key  5   d , an JKL key  5   e , an MNO key  5   f , a PQRS key  5   g , a TUV key  5   h , a WXYZ key  5   i , a ZERO key  5   j , a POINTS key  5   k , an ADD key  5   l , an UP scroll key  5   m , a DOWN scroll key  5   n , an ENTER key  5   o , a CLEAR key  5   p  and a CANCEL key  5   q.    
         [0045]    The microcontroller  11  is programmed to determine weights and POINTS® values for food items on the basis of the output of the load cell  12  and user inputs made using the keypad  5  and to accumulate POINTS® values. The skilled person will discern the nature of this programming from the following description of the operational states of the scale  1 . 
         [0046]    Referring to  FIG. 1 , the scale  1  is activated by the user pressing the ON key  5   a . This moves the scale  1  from an off state  21  to an on state  22 . The on state  22  comprises a plurality of substrates  23 , . . . ,  31 . A timer implemented by the microcontroller  11  generates a timeout interrupt if the scale  1  is in the on state  22  and no key presses have occurred for 3 minutes. The microcontroller  11  responds to this timeout interrupt by returning the scale  1  to the off state  21 . 
         [0047]    When the scale is in the on state  22 , the microcontroller  11  regularly reads the output of its analog-to-digital converter  11   b , converts the output of the into a grams (or ounces) value and drives the LCD  4  to display, the grams value. Thus, with nothing placed in the pan  2 , the LCD displays 0 g. However, if an object is placed in the pan  2 , the output of the load cell  12  will change causing the output of the analogue-to-digital converter  11   b  to change and a new non-zero weight will be displayed by the LCD  4 . 
         [0048]    The pressing of the keys of the keypad  5  triggers interrupt handlers and the response of the microcontroller  11  to any key press will be determined by the identity of the key pressed and the state that the microcontroller  11  is currently in. The ABC, DEF etc keys  5   b , . . . ,  5   i  operate in a manner familiar from mobile phones. If a user wishes to input a B, the user presses the ABC key  5   b  twice in rapid succession. Similarly, if the user wants to input a T, the user presses the TUV key  5   h  once. The operation of any of the ABC, DEF etc keys  5   b , . . . ,  5   i  triggers a timer in the microcontroller  11  and the microcontroller does not settle on the input letter until the timer has expired without one of the ABC, DEF etc keys  5   b , . . . ,  5   i  being pressed. In the interests of clarity, the input of letters using multiple key presses will be treated as a single event in the following description of the operation of the scale  1 . 
         [0049]    On entering the on state  22 , the scale is placed in a ready state  23  in which the current weight is displayed on the LCD  4 . 
         [0050]    If a letter key  5   b , . . . ,  5   i  is pressed in the ready state  23 , the scale  1  moves to a display letters state  24  in which the input letter is displayed. Further operations of letter keys  5   b , . . . ,  5   k  in the display letters state  25  add letters to the display. Pressing the CLEAR key  5   p  in the display letters state  25  deletes the most recently input letter and, if the last letter is removed, returns the scale  1  to the ready state  23 . 
         [0051]    If one of the scroll keys  5   m ,  5   n  is pressed in the display letters state  25 , the microcontroller  11  will attempt to move the scale  1  into a display item name state  26 . The microcontroller  11  responds to the scroll key press by finding respectively the first or last item in the database whose name begins with the displayed letters. For example, if “MA” has been entered, pressing the DOWN scroll key  5   n  would result in the entry in the database for macadamia nuts being located and MACADAMIA NUTS being displayed on the LCD  4 . If an entry is found in the database, the scale  1  moves to the display item name state  26 , otherwise it remains in the display letters state  25 . 
         [0052]    Pressing the scroll buttons  5   m ,  5   n  in the display item name state  26  causes the microcontroller  11  to step forward and backwards through the database, displaying the item name for each entry visited. 
         [0053]    If the ADD key  5   l  is pressed in the display item name state  26 , the microcontroller  11  first determined whether the ENTER key  5   o  was pressed immediately before the ADD key  5   l  and, if not, displays a confirmation prompt on the LCD  4  requiring the user to press the ENTER key  5   o  to proceed. If both the ADD and ENTER keys  5   l ,  5   o  have been pressed, the specific POINTS® value for the displayed item is retrieved from the ROM  13  and multiplied by the current weight in grams derived from the current output of load cell  12 . Then in a store POINTS® state  27 , the resulting absolute POINTS® value is stored in the microcontroller&#39;s RAM  11   e  together with the identity of the item and the current measured weight, and the legend “FOOD ADDED”. Pressing of a letter key  5   b , . . . ,  5   i  in the store Points state  27  returns the scale to the display letters state  24 . 
         [0054]    Pressing the POINTS® key  5   k  in the display item name state  26  or the store POINTS® state  27 , moves the scale  1  to a display POINTS® state  28 . In the display POINTS® state  28 , the microcontroller  11  retrieves the specific POINTS® value for the displayed item, if any, and multiplies it by the current measured weight in grams. To this is added POINTS® values which have been stored in the microcontroller&#39;s RAM  11   e  in the store POINTS® state  27  and the result is then displayed on the LCD  4  with the legend “CURRENT TOTAL”. 
         [0055]    Pressing one of the scroll keys  5   m ,  5   n  in the display POINTS® state  28 , the scale  1  moves to a show entered items state  29  in which the contents of the microcontroller&#39;s RAM  11   e  can be stepped through. If in this state, the POINTS® key  5   k  is pressed, the currently displayed entry is updated with the POINTS® value corresponding to the current measured value, in an update stored POINTS® state  30 . In this way, amounts of food can be varied without having to restart the whole process from the beginning. 
         [0056]    Following the update stored POINTS® state  30  or in response to the CANCEL key  5   q  being pressed in the show entered items state  29 , the scale  1  returns to the display POINTS® state  28 . 
         [0057]    If the ADD key  5   l  is pressed in the display POINTS® state  28 , the scale  1  moves to the store POINTS® state  27  in which the most recently selected item and its associated POINTS® are stored in the microcontroller&#39;s RAM  11   e.    
         [0058]    If the CLEAR key  5   p  is pressed in the display POINTS® state  28 , the entries stored in the microcontroller&#39;s RAM  11   e  are deleted in a clear memory state  31 . When the entries have been deleted and the scale  1  moves to the ready state  23 . 
         [0059]    If the ZERO key  5   j  in any of the ready, display letters and display item name states  23 ,  25 ,  26 , the scale  1  enters a zeroing state  24  in which the display is zeroed and then returns to the previous state  23 ,  25 ,  26 . Zeroing the display sets an offset which is subtracted from the weight corresponding to the output of the load cell  12  to provide the current weight used in the aforementioned calculations. 
         [0060]    Thus, it can be seen that using a scale according to the present invention, a user can place a sequence of food items in the pan  3  and get a display of the accumulated POINTS® for the food items by suitable manipulation of the keys of the keypad  5 . 
         [0061]    A second embodiment of the present invention is identical to that described above with the exception of the definition of the single-valued nutritional indicator. In the second embodiment, the single-valued nutritional indicator is a value for a food item defined by: 
         [0000]    
       
         
           
             p 
             = 
             
               
                 c 
                 
                   k 
                   1 
                 
               
               + 
               
                 f 
                 
                   k 
                   2 
                 
               
               - 
               
                 r 
                 
                   k 
                   3 
                 
               
             
           
         
       
     
         [0000]    where p is the resultant POINTS® value, c is the calorific value of the food item in kilocalories, f is the total fat content of the food item in grams, and r is the dietary fiber content of the food item in grams. Thus, p is monotone increasing with c and f and monotone decreasing with r. In preferred embodiments k 1 &gt;k 2 &gt;k 3 . In more preferred embodiments k 1  is constant, k 2  is in the range k 1 /3 to k 1 /5, and k 3  is in the range k 1 20 to k 1 /5. For example, k 1  may be 50, k 2  may be 12, and k 3  may be 5. 
         [0062]    In other embodiments, the nutritional parameter may be related solely to the calorific value of the food items or solely to the carbohydrate content of the food items. 
         [0063]    While the present invention has been exemplified by numerous embodiments, the scope of the invention intended to be protected is defined by the following claims and their equivalents recognized under law.