Patent Publication Number: US-2012041344-A1

Title: Apparatus and method for estimating body fat mass

Description:
TECHNICAL FIELD 
     The present invention relates to an apparatus, a system and methods for the determination of two-dimensional coordinates of a person, such as a child or adolescent, reflective of e.g. the body fat mass and degree of obesity of the same. 
     BACKGROUND 
     Obesity is a significant and growing health problem, well known and prevalent in the western world. To the individual, being overweight or obese is a major negative physical, medical and very often psychological, factor. To the society, obesity amongst the citizens constitutes a large economic factor, primarily due to the cost related to dependant secondary diseases and conditions, such as diabetes and cardiovascular malfunction. 
     Overweight children and adolescents have a significantly higher risk of becoming overweight or obese adults in comparison to children and adolescents with a normal body fat mass, respectively. Hence, it is of great importance to provide methods and means for measurement and quantification of body fat mass, especially in the groups of children and adolescents. 
     The absolute figures, i.e. metrics for the degree of obesity, serve the physician or parents as a check on whether or not the child or adolescent is in a risk zone by comparison with statistic data. He or she may furthermore compare these metrics with historic individual data to assess the improvement with regard to decrease in body fat mass over time. Based on the outcome of these comparisons, the physician, the parents, or anyone else being responsible, may take suitable measures with regard to style of life, physical activity and healthful eating. 
     In addition to being highly valuable for the classification and tracking of body fat mass of persons where potential (future) obesity is of concern, these metrics may also be used for the analog classification and tracking of persons where abnormally low body fat mass is of concern, such as for persons with anorexia nervosa. 
     A well known method to measure and indirectly quantify a persons body fat mass is to measure that persons weight and length on a scale, and there from calculating the corresponding body mass index (BMI) reflective of health risks. Although the measurement of a persons BMI is a relevant metric for body fat mass in the adult, the same is not true for a child or adolescent as such a person is in a growing state and, accordingly, the BMI naturally changes over time and is thus only partly dependant of the body fat mass. 
     EP 1,269,917 A1 describes the measurement of skinfold thickness, related to body fat mass, of a living body by essentially placing a protruding part onto an umbilical region of the living body and irradiating the same with the light from a light source, and detecting the diffusely reflected light with a photodetector. Disadvantages of this methodology include the discomfort caused to the person being measured by e.g. the protruding part, which by necessity is temporarily deforming the persons skin, and by the holding means, which is provided with e.g. a string or a belt wrapped around the persons body. 
     EP 1,629,772 A1 discloses a child body composition meter in the form of a platform comprising a bioelectrical impedance measuring section, a weight measuring section and a programmed microcomputer. The data generated by the former two being related to body fat mass. Disadvantages of this platform include the inability to get quantitative data related to the local body fat mass at different parts of the body and the advanced electronics needed to measure, transform and present the generated data. Furthermore, the child being measured needs to actively and potentially uncomfortably stand on the platform with naked feet in order to allow for e.g. an electric current, necessary for the bioelectrical impedance measurement, to be passed through the body. 
     EP 1,583,019 A2 discloses a system for and a method of managing growth and development of a child. The system includes, similar to EP 1,629,772 A1, a biological information measuring module which is based on the principles of e.g. the measurement of bioelectrical impedance, related to body fat mass. The disadvantages of the system disclosed in EP 1,583,019 A2 include the disadvantages of the child body composition meter disclosed in EP 1,629,772 A1. 
     EP 1,645,223 A2 describes an apparatus and a method of measuring fat thickness in a target body part of a person based on the principles of absorption and reflection of near infrared rays. Disadvantages of this method include the necessity of a calculator, and of complicated analysis and transformation of the generated raw-data, in order to retrieve metrics related to body fat mass. Furthermore, the long term health effects of penetrating electromagnetic radiation is widely debated and not yet fully understood. 
     EP 2,016,895 A1 describes a body composition measuring apparatus for estimating a body composition index. The apparatus includes an abdominal width measurer which is employing reflection-type contactless distance measuring sensors arranged on a frame to measure the abdominal width of a person inside the same. These sensors are measuring a gap distance between a position of a sensor and a position of a point to be measured. Each sensor includes a light emitter for emitting light, and a light receiver for receiving the light reflected from e.g. a person&#39;s skin. Disadvantages of reflection-type distance measuring sensors of e.g. this method include potential range detection errors arising from energy emanations from other sensors and light energy scattering. Furthermore, this type of sensors depend on satisfactory reflection of light from, in this application, human skin, which might be poor if e.g. the emitted light is entering at an angle not being perpendicular to the skin surface, or if the skin is of a type with poor ability to reflect light, such as dark skin. 
     Hence, there is room for improvements, namely a new technique, for measuring or estimating body fat mass and degree of obesity of a person, which technique allows for accurate measurements with limited measurement errors and limited discomfort and health risks to the person, while simultaneously limiting the need for advanced electronics and for passing current through the body of the person, or exposing the same to penetrating electromagnetic radiation. 
     SUMMARY 
     It is an object of the present invention, considering the disadvantages mentioned above, to provide a simple and mobile apparatus and system to be used for the collection of relevant data based on accurate measurements with limited measurement errors being reflective of a person&#39;s body proportions in a cost effective way that causes minimal discomfort and risk to the person. 
     It is another object of the present invention, to provide a method for the use of the apparatus and system of the invention for the collection of two-dimensional coordinates or equivalent data, reflective of a person&#39;s body proportions and the body fat mass of the same. 
     These and other objects, which will appear from the following description, have now been achieved by an apparatus and system according to the present invention which comprises a first and a second bar, said first bar being configured to be movable along said second bar and said first bar being perpendicular to said second bar; first connecting means for connecting said first bar to said second bar; and a light emitting device configured to emit light in a direction perpendicular to the plane defined by the first and second bars and towards said person. 
     Further features of the invention and its embodiments are set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of non-limiting embodiments of the present invention, reference being made to the accompanying drawings, in which 
         FIG. 1  is a schematic view of an apparatus, placed with a first bar in the vertical direction and with a second bar in the horizontal direction and with a person P placed horizontally with a sagittal plane of the body facing the apparatus, according to an embodiment of the present invention; 
         FIG. 2  illustrates an embodiment of the present invention, showing the left side, i.e. sagittal view, of the body of a person P lying on the back on a flat horizontal surface, as seen from the z-direction of the apparatus; 
         FIG. 3  is a schematic view of an apparatus comprising an integrated bench, an array of light beams illuminating light sensing means positioned on a third bar and a sheet of light illuminating an extension unit provided with light sensing means, according to an embodiment of the present invention; 
         FIG. 4  is a schematic view of an apparatus comprising a connecting bar provided with a light emitting device constituted by a plurality of lasers that emits a plurality of beams of light toward an integrated bench, according to an embodiment of the present invention; 
         FIG. 5  is a schematic view of an apparatus comprising a bed plate placed on a vertical bench and onto which a person may be placed and onto which a supporting bar with a shape of an “inverted L” is fastened, a hanging bar fastened onto the supporting bar and extending in the x-direction above the bed plate, a second sliding member slidingly engaged to the hanging bar and onto which a camera and a light emitting device is attached, the light emitting device is emitting a sheet of light which is giving rice to a reflection in the form of a line on the bed plate and on the bench below it, a control unit in the form of a portable PC which is connected to the light emitting device and the camera to provide output to and input from these, according to an embodiment of the present invention; and 
         FIG. 6  is a schematic sectional view from above a person lying down horizontally on a flat surface being exposed to a sheet of light emitted from a light emitting device from right above whereby a line is projected partly on the surface and partly on the exposed part of the body of the person. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Several embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in order for those skilled in the art to be able to carry out the invention. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The embodiments do not limit the invention, but the invention is only limited by the appended patent claims. Furthermore, the terminology used in the detailed description of the particular embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. 
     As well known, the x-y-z coordinate system, wherein the constituting x-, y- and z-axis are all perpendicular to each other, is commonly used to describe e.g. points, lines and planes in three dimensions. In the description, embodiments and claims of the present invention, the x-y-z coordinate system is used with reference to the apparatus  100 , such that the x-axis of the x-y-z coordinate system is always parallel with the direction of second bar  102 , the y-axis of the same is always parallel with the first bar  101 , and the corresponding z-axis is always perpendicular to the plane defined by the first and second bars  101 ,  102 , unless otherwise indicated. Hence, for example, with “x-direction” is to be understood a direction in space parallel to, or along, the elongation of the second bar  102 , and with “x-position” is to be understood a point in a plane transverse to the same position on the second bar  102  or the relative position on the second bar  102 , unless otherwise indicated. 
     In the description, embodiments and claims of the present invention, the well known terms “horizontal” and “vertical”, or derived forms thereof, are used to describe e.g. points, lines and planes in the room, such that the vertical direction is always parallel to the direction of the force of gravity, unless otherwise indicated. 
     Embodiments of the present invention will now be described below with reference to  FIGS. 1 to 6 . 
     According to an embodiment of the invention as illustrated in  FIG. 1 , there is provided an apparatus  100  and a method for the measurement and determination of two-dimensional coordinates of a person P, including essentially a straight first bar  101 , a straight second bar  102  and a light emitting device  104 . 
     The first bar  101  is connected to the second bar  102  by first connecting means  105  to allow a user to move the first bar  101  to a position in the x-direction on the second bar  102  as desired by the user and only limited by the effective length of the second bar  102 . The angle between the first bar  101  and the second bar  102  is substantially 90° independent of the x-position of the former. 
     First bar  101  and second bar  102  may be made of the same or different materials, preferably selected from materials known in the art as constituents of bars, such as wood, plastic, aluminum or suitable composites. Even more preferred is a suitable material that is cheap, light and environmentally friendly in order to make the total cost of the apparatus  100  relatively low, the transportability of the apparatus  100  relatively high, and the apparatus  100  recyclable to a great extent, respectively. 
     Second bar  102  is preferably made of a heavier material, or has a greater total mass, than first bar  101  for the sake of stabilization of apparatus  100  when it is positioned with the first bar  101  and the second bar  102  oriented in the vertical and horizontal direction, respectively. 
     When the first bar  101  has been moved to a desired x-position, it remains in that position by first connecting means  105  of the connection between the first and second bars  101 ,  102  until a user moves it to another x-position as desired. 
     A first sliding member  103  is connected to the first bar  101  by second connecting means  106  to allow a user to move the first sliding member  103  to a position in the y-direction on the first bar  101  as desired by the user and only limited by the effective length of the first bar  101 . When the first sliding member  103  has been moved to a desired y-position, it remains in that position by second connecting means  106  of the connection between the first bar  101  and the first sliding member  103  until a user moves it to another y-position as desired. 
     First and second connecting means  105 ,  106  include, for example, a tightening bolt, a natural friction element, or a fitting suitable for connecting a first bar to a second bar, and which fitting is well known to the person skilled in the art. One or both of first and second connecting means  105 ,  106  are preferably of a user-friendly type so that a user of the apparatus  100  intuitively understands their function and proper handling. 
     The x-position of the first bar  101  is equivalent to its, at that point in time, relative position on the second bar  102 , which is determined by means for x-position determination  107 , such as a visual reading of a scale positioned on the second bar  102 . The means for x-position determination  107  may also be, as known in the art, an electric, magnetic, and/or mechanic sensor determination means, suitably triggered by a user, on the second bar  102 . 
     The y-position of the first sliding member  103  is equivalent to its, at that point in time, relative position on the first bar  101 , which is determined by means for y-position determination  108 , such as a visual reading of a scale positioned on the first bar  101 . The means for y-position determination  108  may also be, as known in the art, an electric, magnetic, and/or mechanic sensor determination means, suitably triggered by a user, on the first bar  101 . 
     Visual reading of a scale positioned on the first or second bar  101 ,  102  is intuitive to a user and prevents otherwise common errors associated with more complicated systems for collection of data. 
     A light emitting device  104  is connected to the first sliding member  103  whereby it, at all times, has the same x-position as the first sliding member  103  and in such a way that the emitted beam of light  109  is substantially perpendicular, i.e. normal to, the plane defined by the first and second bars  101 ,  102 , i.e. the plane defined by the y-axis and the x-axis, respectively. The emitted light may also be a sheet of light, traveling in a plane substantially perpendicular to the plane defined by the first and second bars  101 ,  102 . The beam of light  109 , or the center of the sheet of light, may have a direction within an error margin of, for example, 0 to 3°, relative an imaginary line perpendicular to the plane defined by the first and second bars  101 ,  102 . Thus, the center of the beam of light  109 , or the center of the corresponding sheet of light, has practically the same y- and x-coordinates along an axis (z) perpendicular to the plane defined by the y-axis and the x-axis. 
     Validation of the precision and accuracy of the beam of light  109 , and thus the apparatus  100  in its setting, may be done simply by directing the same toward reference spots, for example on a wall, and comparing the corresponding x- and y-positions with accurate reference values. This way of validation is comparably simpler than the validation of many other instruments or systems used for the estimation of body fat mass. 
     Means  104   a  for connecting the light emitting device  104  to the first sliding member  103  include, for example, bolts or screws or suitable adhesive means. 
     The light emitting device  104  may also be connected to the first sliding member  103  by means  104   a  of a suitable gyrostabilizer known in the art, in order to e.g. stabilize the direction of the emitted beam of light  109  against e.g. temporal dislocations or vibrations of the apparatus  100 . 
     In the case the direction of the beam of light  109  is, after triggered by the user as desired, periodically varying in one plane, such as in the y-plane or in the x-plane, an imaginary line drawn from the center of the resulting projection in the x-y-plane to the light emitting device  104 , is practically parallel to the z-axis of the x-y-z coordinate system. 
     In order to prevent e.g. accidental tilting or dislocation of the apparatus  100 , such as when the first bar  101  is placed in a vertical direction and the second bar  102  is placed on a horizontal surface, which would cause the beam of light  109  to no longer be perpendicular to the vertical-horizontal plane in this example, the shape and form of the second bar  102  may be such that it safely supports the apparatus  100  from tilting or dislocating. This may be accomplished by providing the second bar  102  with a flat bottom side with a large surface area and, optionally, being relatively heavy, to provide a good support when the apparatus  100  is placed horizontally on a flat surface, such as the floor of a room or a table. Also, the second bar  102  may be provided with separate means to secure the apparatus  100  to the surface on which it is placed, such as screws, straps, magnets, adhesive means or a holder of the kind commonly used to secure table lamps to a table. 
     According to one embodiment of the invention, the apparatus  100  may be positioned in such a direction to, and at such a distance from, a person P, that when the beam of light  109  is exposing the same, or an immediately nearby extension unit  110  (see  FIG. 2 ), the resulting reflected light is clearly visibly detectable by a user of the apparatus  100 , or detectable by other suitable means, such as by a photodetector well known in the art. 
     The photodetector, employed for the detection of reflected light from a person P or extension unit  110  above, may be a camera such as a WEB-camera. 
     The distance between the light emitting device  104  of the apparatus  100  and the person P during measurements is preferably 0.01 to 10 m, and even more preferred 0.01 to 2 m. 
     Examples of said immediately nearby extension unit  110  include a piece of material, such as wood, plastic or metal, that is no larger in size or weight than it can be placed on a person P without unacceptable discomfort for the same. Extension unit  110  serves as an extension of a persons P body by allowing reach of the beam of light  109  when being placed on parts of the body that is not readily reachable by the beam of light  109  in the position that the person P is placed. Extension unit  110  may, for example, be placed on the breastbone of a person P lying horizontally on the back with the beam of light  109  coming directly from either the left or the right side, i.e. perpendicular to the sagittal plane of the body. Extension unit  110  may furthermore be provided with one or several light sensing means, which may be selectively sensitive to the light emitted from the light emitting device  104  so that a signal is transmitted from the object upon exposure of that light. Light sensing means, selectively triggered to transmit a signal by light of a particular wavelength, is well known in the art. The signal may be a radio-signal that can be intercepted by a receiver, such as a receiver integrated in or with a computer or control unit  111 , or a sound-signal from electronics optionally integrated with the object, that could be heard by a user of the apparatus  100 , all well known in the art. The signal may also be a fluorescent light readily seen by a user of the apparatus  100  and due to a coating of the object with a fluorescent material well known in the art. 
     According to one embodiment, the light emitting device  104 , from which the beam of light  109  is coming, is preferably a laser, for example, of the same type as employed in pen-lasers used in public presentations, or a suitable aiming laser commonly used for firearms that may be purchased from, for example, Laser Devices Inc. The light emitting device  104  may also be, either by selection of such mode by a user or constantly, a laser in which the emitted beam of light  109  is periodically changing direction in the x- or the y-plane, i.e. the plane of the second bar  102  and the first bar  101 , respectively, with such a rate that user of the apparatus  100  gets the visual impression of a line on the object, such as a person P, which the beam hits. The user is thereby guided in the identification of which parts of the object are located along the current e.g. x- or y-direction. 
     In order to make e.g. the visual impression possible, the light emitting device  104  may alternatively emit a sheet of light generated by, in the light emitting device  104 , integrated optics and/or one or several lenses as well known in the art, that spread an initially generated beam of light into a sheet of light formed as the letter “V”. The sheet of light is optionally initiated by selection of the user by switching between different modes of the light emitting device  104 , such as “beam mode” and “sheet mode”. The sheet of light is generating the visual impression of a line on the object, such as preferably in the coronal or transverse plane of a person P, or on extension unit  110 , which the sheet of light hits. 
     According to one embodiment as partly illustrated in  FIGS. 1 and 2 , during measurements, a person P, such as a child or adolescent, may be placed lying down horizontally on the back in front of the apparatus  100 , preferably in a comfortable way, such as being placed on a suitable bed or table with a flat surface, with an imaginary line along the spinal cord being essentially parallel to the x-axis, i.e. the second bar  102 , and the same imaginary line being essentially perpendicular to the z-axis, i.e. the direction of the beam of light  109 . 
     During measurements, a person P may also be standing up on the feet in an upright horizontal direction with the apparatus arranged so that the beam of light  109  or the center axis of the corresponding sheet of light, i.e. the z-direction of the apparatus, is perpendicular to e.g. the sagittal or coronal plane of the body of person P. 
     During measurements, a person P, such as a child or adolescent, is however preferably lying down horizontally on the back as this position is highly comfortable and the person P may even sleep. 
     The placement of a person P and the apparatus  100  may occur in any order of convenience and the person P is preferably naked or dressed in tight thin clothing on the parts of the body from which coordinates are to be collected. 
     A user of the apparatus  100 , which may be a nurse, doctor, physician, teacher, parent or anyone else with a desire to collect data of relevance for a person&#39;s P status with regard to body fat mass, may independently and as desired move the first bar  101  and the first sliding member  103  to position the beam of light  109 , or the center of the same, at any x- and y-coordinate within the limits defined by the effective length of the second and first bars  102 ,  101 , which is preferably such that a person P may be exposed at any part of the body, and even more preferred at the part of the body in between the neck and the upper part of the thigh, by the beam of light  109 . 
     When a desirable relative placement of a person P and the apparatus  100  has been arranged in accordance with the description above, such as the arrangement as illustrated in  FIG. 1 , the user of the apparatus  100  may select a first x-position of the person&#39;s P body by moving, simultaneously or one at a time, the first bar  101  and the first sliding member  103  until the reflection of the beam of light  109 , which may be visually detected by the user as a spot or line on the person&#39;s P body, corresponds to the first x-position. The first bar  101  may then be secured at this first x-position by first connecting means  105  and its relative placement on the second bar  102 , i.e. the corresponding x-coordinate of the person P, may be noted or by other means registered by the user. 
     When the first bar  101  is secured at the first x-position, a user may move the first sliding member  103  from a position where the reflection of the beam of light  109  from the person&#39;s P body is detectable, to a position where the same reflection from the body no longer is detectable, or the beam of light  109  is hitting an object behind the body, or the reflection distinctly changes character as is occurring when the beam of light  109  misses the body completely or hits it at a low angle, respectively. The beam of light  109  may also move away from the body and reach extension unit  110 . At that point, a user may note or register the relative placement of the first sliding member  103  on the first bar  101 , equivalent to the “limiting y-coordinate” of person P, at the selected first x-position, equivalent to the “coherent x-coordinate” of person P for said limiting y-coordinate. 
     When the beam of light  109  misses the body of the person P, the detection of the beam of light  109  with the same type of light sensing means selectively sensitive to the light emitted from the light emitting device  104 , as herein before mentioned, may aid the user in the selection of x- and y-positions. For example, a suitable screen or wall, positioned on the opposite side of person P in relation to apparatus  100  and in the direction of the beam of light  109 , may be provided with said light sensing means and thus transmit an indicative signal when the beam of light  109  hits the same. Preferably, extension unit  110  and the screen or wall are provided with different light sensing means to allow for easy differentiation of the occurrences of the beam of light  109  hitting the former or the latter. 
     Thereafter, a second x-position may be selected, and the same procedure as conducted for the first x-position may be repeated in order to collect the corresponding limiting y-coordinates for the second x-position, i.e. second coherent x-coordinate. Any number of x-positions, i.e. coherent x-coordinates, may accordingly be selected for the collection of the corresponding limiting y-coordinate(s). Generally the selection of, and the determination of the corresponding limiting y-coordinate(s) at, two different x-positions, i.e. corresponding coherent x-coordinates, is preferred. 
     The first sliding member  103  may be moved by a user in two directions, i.e. toward the second bar  102  or away from the same, to allow for the registration of, for example, two limiting y-coordinates of a person P at any selected x-position, i.e. coherent x-coordinate. One limiting y-coordinate may correspond to the intersection between the persons P body and the surface on which the person P is placed, such as lying down on the back, and constitutes a useful vertical reference line L 3  in the case said surface is horizontal, or to the lower ending of the person&#39;s P body in the case this is not in contact with the underlying surface. 
     In addition, a skilled user of the apparatus  100 , may accordingly collect x-y-coordinates corresponding to different parts of a person&#39;s P body, such as the highest point of the hipbone M 1  and the lowest point of the ribs M 2 , and x-y-coordinates M 5  corresponding to the extension unit  110 , which may represent the height of the breastbone from a vertical reference line. 
     Different data sets, each consisting of one or several of limiting y-coordinate(s) together with the respective coherent x-coordinate(s), as well as x-y-coordinate(s) of different body part(s) and/or extension unit  110  and/or the y-coordinate corresponding to said vertical reference line, may be collected in accordance with the description above by different arrangements of a person P in relation to the apparatus  100 . For example, the person P may be placed horizontally with the back facing downwards so that one of the person&#39;s P sides is facing the apparatus  100 , i.e. a sagittal view, or with the side downward so that the person&#39;s P front is facing the apparatus  100 , i.e. a coronal view. These arrangements would, upon the collection of data according to the description above, result in two data sets, one corresponding to a sagitall projection of a person P lying horizontally on the back and one corresponding to a coronal projection of a person P lying horizontally on the side, respectively. 
     During collection of the data sets, the beam of light  109  can advantageously not be sensed by the person P, and the beam of light  109  is preferably of a non penetrable wavelength, thus opposing a minimal risk of any health hazard to the person P. 
     In addition, x-y-coordinates may be collected accordingly in, for example, the sagittal and in the coronal plane of a person A who is standing up vertically, by arranging the apparatus  100  with the second bar  102  horizontally, the first bar  101  vertically, and with the beam of light  109  directed towards the person P. 
     Data sets, as described and collected according to the description and method above by employment of the apparatus  100 , generated at different time-points, such as time-point with an interval in between them from several days to a few month, may be further mathematically manipulated and analyzed by the one skilled in the art and are valuable for the generation of metrics or anthropometric measurements and for the monitoring over time of the health status, with regard to e.g. body fat mass, of a person P. 
     According to one embodiment of the invention, there is provided a control unit  111  connected to the apparatus  100 , into which a user may register data, or from which a user may read data from the apparatus  100 , such as the x-y-coordinates of the beam of light  109  or data from any related sensor(s), such as light sensing means, or by which a user may initiate calculations on stored data and, optionally, via which a user may control the apparatus  100 . The control unit  111  may store data from the apparatus  100 , such as data from the means for x-, y- or z-position determination and perform calculations based on the same, such as calculating indexes and/or metrics known in the art. The control unit  111  enables a user of the apparatus  100  to read output, such as the present x-position of the first bar  101 , the present y-position of the first sliding member  103 , and calculated indexes or metrics, and store information of relevance, such as patient records comprising patient data and related two-dimensional coordinates, e.g. x- y- and x-z-coordinates, and calculated indexes and/or metrics. The patient data may comprise, for example, the name, the address, the weight and height, medical history and date of birth of a person P. A user of the apparatus  100  may optionally control the positioning of the first bar  101  and the first sliding member  103  via the control unit  111  as the same may be in control of devices known in the art, such as servo-motors, that automatically moves the first bar  101  and the first sliding member  103  to positions as desired by the user. A user of the apparatus may optionally control the mode of the light emitting device  104 , or the corresponding, via the control unit  111 , e.g. switching between “beam mode” and “sheet mode”, as desired. The control unit may be a personal computer (PC), provided with suitable software and hardware for input/output, or any other suitable control unit as well known in the art. 
     According to one embodiment of the invention, there is provided an apparatus  100  for the collection of two-dimensional coordinates of a growing child or adolescent lying down horizontally on the back, said coordinates being coordinates in the sagittal plane of the body. 
     According to one embodiment of the invention as illustrated in  FIGS. 3 and 4 , the apparatus  100  is provided with an integrated bench  112  that may be stationary in, or (un)foldable into, the x-z-plane, i.e. the plane perpendicular to the plane defined by the first bar  101  and the second bar  102 . The integrated bench  112  has a flat upper surface located at, either permanently or when (un)folded into, a predetermined y-coordinate corresponding to reference line L 3 , whereby a user of the apparatus does not need to separately determine the y-coordinate of reference line L 3  as this is known. The integrated bench  112  may be connected to the second bar  102  by suitable connecting means known in the art, such as hinge joints  126 . Means for facilitating the folding and unfolding of the integrated bench  112  are known in the art. For example, the integrated bench  112  may consist of separate parts that are connected with hinge joints  126  in a suitable way known in the art, whereby a flat comfortable surface in the x-z-plane is formed as the bench is (un)folded by a user who is setting up the apparatus for measurement of two-dimensional coordinates of a person P. When the integrated bench  112  is set for use of the apparatus  100  with the first and second bars  101 ,  102  arranged in the vertical and horizontal direction, respectively, i.e. being (un)folded into the x-z-plane, its upper surface is preferably located at a level below any beam of light of the apparatus  100  traveling in the z-direction, or within the lower 10% of the y-direction of the total possible range of such beams. The integrated bench  112  is preferably of a type which allows the apparatus  100  to be foldable into a format, such as “briefcase format”, whereby the apparatus  100  is highly movable and can be easily transported between different locations for measurements. 
     According to one embodiment of the invention as illustrated in  FIGS. 2 ,  3  and  4 , the light emitting device  104  may emit a plurality of beams and/or sheets of light, preferably a plurality of beams of light  113  and one sheet of light  114 . Hence, the light emitting device  104  may comprise a plurality of light emitting sources, preferably lasers, located at a short distance, such as 0.1 to 5 mm, from each other. The light emitting sources may be placed on a row in the y-direction, i.e. in the same direction as the first bar  101 , and the distance from the first to the last one in this row is preferably greater than the distance between M 4  or M 5 , and L 3 , i.e. the greatest vertical distance in the sagittal plane, of a person P lying on the back on a horizontal flat bench. The light emitting device  104  may optionally be positioned directly onto the first bar  101  (as illustrated in  FIGS. 3 and 4 ), i.e. without the need for a connection to a first sliding member  103 . 
     According to one embodiment of the invention, light sensing means  115  may consist of an array of photo electric sensors, i.e. a plurality of photo electric sensors, preferably selectively sensitive to the light emitted by light emitting device  104 , as known in the art. The photo electric sensors are preferably placed within a distance of 0.1 to 5 mm from each other in a row in the y-direction and may be of an integrated type as known in the art. 
     According to one embodiment of the invention, light sensing means  115  may consist of an array of photo electric sensors, i.e. a plurality of photo electric sensors, synchronized by suitable means known in the art, such as mechanically or electrically, with the plurality of beams of light  113 , whereby each and one of these sensors is capable of detecting illumination caused by the corresponding single beam of light, coming from the corresponding light source which is placed right in front of it. Upon such detection of illumination, every single sensor may be capable of generating a positive light indication signal. Such signals and their practice are well known in the art and include, for example, an analog electric signal that may be converted to a digital signal (e.g. “1” of “1” or “0”), which may be further transmitted as input to a computer or to control unit  111 , to allow for automatic calculation of y-coordinates. For example, should a single given beam of light of the plurality of beams of light  113  reach the corresponding sensor of the plurality of photo electric sensors, a digital “1” is generated. If, however, this single beam of light does not reach the corresponding sensor, as in the case of interruption by the body of a person P, the corresponding digital “0” is generated. 
     According to one embodiment of the invention, light sensing means  115  consists of one single photo electric sensor, whereby the illumination of the light sensing means  115  with one or several of the plurality of beams of light  113  is resulting in a positive light indication signal. 
     According to one embodiment as illustrated in  FIGS. 3 and 4 , the apparatus  100  is provided with a connecting bar  117 , extending in the z-direction, which connects the first and third bar  101 ,  116  to keep these parallel in the y-z-plane independent of the relative position of the first bar  101 . The connecting bar  117  is preferably removable and replaceable to allow for easy assembly of the apparatus  100  when a person P is placed in its immediate vicinity or, for example, on an integrated bench  112  of the same, for measurements. 
     According to one embodiment, the connecting bar  117  is provided with a second light emitting device,  120  or  123 , from which one or several beams of light are emitted in the y-direction and towards a person P. 
     According to one embodiment, the second light emitting device is a single laser  123  that is movable along the connecting bar  117  and emits a single beam of light  124 . Furthermore, the single laser  123  or the connecting bar  117  may be provided with means for relative z-position determination as known in the art, such as a scale  125  on the connecting bar  117 . 
     According to one embodiment, the second light emitting device is constituted by a plurality of lasers  120 , located at a distance of 0.1 to 5 mm from each other, and placed in a row on and along the connecting bar  117 , and emitting a plurality of beams of light  121 . 
     According to one embodiment as illustrated in  FIG. 4 , the integrated bench  112  is provided with laser selective sensing means  127 , whereby the light emitted from the second light emitting device,  120  or  123 , is detectable. Upon illumination of the laser selective sensing means  127  with one or several of the plurality of beams of light  121 , or with the single beam of light  124 , laser selective sensing means  127  may result in a positive light indication signal, in analogy to the positive light indication signal of light sensing means  115 , which may be further transmitted as input to a computer or to control unit  111 . The laser selective sensing means  127  are preferable covering the entire surface of the integrated bench  112  on the same side as a person P is placed, whereby the area of the bench outside the area of the sagittal plane of the body of a person P is covered by laser selective sensing means  127 . Hence, laser selective sensing means  127  may detect the closest beam of light, relative the body, from the second light emitting device,  120  or  123 , which is outside the area of the sagittal plane of the body of a person P. Suitable laser selective sensing means  127  are known in the art and include any suitable photosensitive detector, that may consist of an array of photosensitive semiconductors capable of generating an electric output signal upon illumination, that is sheet-formed and preferably foldable to allow facile placement on the integrated bench  112 , in combination with a light filtering sheet, in order to allow only light of the same wavelength as the light emitted from the second light emitting device,  120  or  123 , to reach the photosensitive detector. 
     According to one embodiment, the control unit  111  may (a) read input in the form of one or several positive light indication signal(s) from the light sensing means  115 , or from the laser selective sensing means  127 , (b) transmit output signals in the form of signals to the light emitting device  104 , or to the plurality of lasers  120 , or to the single laser  123 , whereby each and one of the from any of said device or laser(s) emitted beam(s) of light individually can be turned on or off in accordance with an algorithm stored in control unit  111 . 
     According to one embodiment, the apparatus  100  comprises (a) a plurality of lasers  120 , emitting a plurality of beams of light  121 , (b) a light emitting device  104 , emitting a plurality of beams of light  113 , (c) light sensing means  115  consisting one single photo electric sensor, capable of transmitting a positive light indication signal to control unit  111 , (d) laser selective sensing means  127 , capable of transmitting a positive light indication signal to control unit  111 , and (e) control unit  111 , wherein a suitable algorithm for control and registration and calculation of data of/from the apparatus  100  is stored. 
     Hence, after having placed a person P horizontally, in accordance with the description herein, and so that the coronal plane of the body is encompassed by the plurality of beams of light  121  and, at least, the upper part of the sagittal plane of the body is encompassed by the plurality of beams of light  113 , two dimensional coordinates of person P may be collected, in the sagittal and coronal plane, at the present x-position of the first bar  101  by: (i) Turning on, each and one and one at a time, the beams of the plurality of beams of light  121 , (ii) Registering the presence or absence of a positive light indication signal from the laser selective sensing means  127  for each beam of light during the time-period it is turned on, (iii) calculating the distance, corresponding to the coronal width of the body, from the first to the last beam of light associated with the absence of a positive light indication signal, (iv) Repeating “i” to “ii”, with the plurality of beams of light  113  in combination with light sensing means  115 , for an estimation of the upper y-coordinate of the body in the sagittal plane, which corresponds to the uppermost beam of light associated with the absence of a positive light indication signal. 
     An additional set of two-dimensional coordinates may thereafter be collected at another x-position by moving the first bar  101  to a new position and repeating steps “i” to “iv”. 
     A user may thus conveniently collect two-dimensional coordinates from both the coronal and sagittal plane of the body of a person P, without the need of person P to move position or be touched in any way. 
     According to one embodiment of the invention, the apparatus  100  comprises a light emitting device  104  that emits a plurality of beams and/or sheets of light, as described herein above, and light sensing means  115  in the form of a row of a plurality of photo electric sensors in the y-direction, as described herein above. The plurality of beams of light  113  and the photo electric sensors are synchronized so that each beam is detected by a corresponding sensor, irrespective of the position of the first bar  101 , provided that no object, such as a person P, is hindering said beam or beams. Means for the synchronization include, for example, a third bar  116  arranged in the y-direction, onto which the sensors are placed, which is mechanically connected, as known in the art, to the first bar  101  by, for example, a connecting bar  117 . Limiting y-coordinates may thus be determined by registration, automatically by a control unit  111  or manually by a user, of e.g. the lowest detected beam of light (for an upper limiting y-coordinate) at the corresponding x-coordinate onto which the first bar  101  is placed at. The distance between the first bar  101  and the third bar  116  may be such that a person P can be placed, lying down horizontally on the back, easily between these bars, and preferably between 0.5 to 1.5 m. 
     According to one embodiment, the light emitting device  104  comprises a plurality of lasers located at a distance of 0.1 to 5 mm from each other, these lasers are placed in a row in the direction of the first bar  101  and emitting a plurality of beams of light  113  in a direction perpendicular to the plane defined by the first bar  101  and the second bar  102 . 
     According to one embodiment, the apparatus  100  comprises a third bar  116  extending in the y-direction and in front of the beams of light  113 . On the third bar  116  is located light sensing means  115  reachable by each and one of the plurality of beams of light  113 . The third bar  116  may be placed in front of the beams of light  113  manually or by other means, such as being mechanically synchronized with the first bar  101  as known in the art. 
     According to one embodiment as illustrated in  FIG. 4 , the apparatus  100  is provided with a fourth bar  122 . The movement of the third bar  116  in the x-direction may be facilitated by the aid of this fourth bar  122 , which extends in the x-direction and is optionally integrated with the apparatus  100 , via for example hinge joints  126  or other suitable means as known in the art. This fourth bar  122  acts as support by allowing the third bar  116  to slide therein by means known in the art, such as a low friction incision, and helps to keep the same in front of the beams of light  113  as the first and third bars  101 ,  116  are moved in the x-direction. 
     According to one embodiment of the invention, the apparatus  100  simultaneously comprises a light emitting device  104 , which emits a plurality of beams and/or sheets of light and is placed on first bar  101 , a third bar  116  provided with light sensing means  115  in the form of photo electric sensors, and an integrated foldable bench  112 . The third bar  116  and the photo electric sensors being mechanically synchronized with the first bar  101  and the plurality of beams  113 , respectively. The bench being foldable into the x-z-plane and configured, as known in the art, for comfortable placement of a person P lying on the back. 
     According to one embodiment of the invention, the light emitting device  104  is emitting a sheet of light  114  in the x-z-plane, and the extension unit  110  is shaped as a rod and provided with light sensing means  118  in the form of a row of a plurality of photo electric sensors, placed at a distance of preferably 0.1 to 5 mm from each other along extension unit  110 . The sheet of light is directed toward a point just above the breastbone of a person P lying horizontally on the back on a flat surface and from whom two-dimensional coordinates are to be collected. The rod-shaped extension unit  110  is placed in a vertical direction on the breastbone of said person P, whereby the single sensor  119 , of the plurality of photo electric sensors, which is located at the same y-coordinate as the sheet of light  114 , is detecting the sheet of light  114 . Accordingly, the distance from the reference line L 3  to the top of the breastbone may be calculated based on the y-coordinate of the sheet of light  114  and the distance from the breastbone to the single sensor  119  detecting the sheet of light  114 . 
     According to one embodiment of the invention, the rod-shaped extension unit  110  is provided with a wireless connection to control unit  111  and with a button, whereby a user may turn on and off the sheet of light  114  with the button, and a signal from the single sensor  119  may be transmitted to control unit  111  for subsequent identification of the same and calculation of the coordinates of e.g. the breastbone of person P. The user may thus not need to be near the control unit  111  for measurement of the coordinates of e.g. the breastbone, but only have to activate the button on extension unit  110 . 
     According to one embodiment of the invention, apparatus  100  may be placed above, such as hanging from the ceiling, a person P lying horizontally on the back on a flat surface, whereby the first bar  101  is positioned horizontally, the second bar  102  is positioned horizontally, and the beam of light  109  or the corresponding beams or sheet(s) of light are directed towards person P, hence permitting collection of two-dimensional coordinates of a person P from the front side, i.e. in the coronal plane, while the person P is lying down on the back. 
     According to one embodiment of the invention, there is provided a method for use of apparatus  100  for the estimation of the body fat mass of a person P, the method comprising (a) placing a person P on the back on a flat surface in the horizontal plane with a side of the body, i.e. sagittal plane, facing the apparatus  100 , the person P being naked on the part of the body from the neck to the upper part of the thigh, (b) registering at least two limiting y-coordinates of the person&#39;s P body, and (c) using said limiting y-coordinates for the estimation of the body fat mass of the person P. 
     According to one embodiment of the invention, the light emitting device  104  of apparatus  100  is a laser, which optionally may be set to periodically change direction of the emitted beam of light  109  in the x-z-, or in the y-z-plane. 
     According to one embodiment of the invention, the light emitting device  104  has built in optics whereby the said device emits a sheet of light shaped as the letter “V”. 
     According to one embodiment of the invention, the y-position of the first sliding member  103 , and the x-position of the first bar  101 , is determined by visual reading of y- and x-scales  108 ,  107 , respectively. 
     According to one embodiment, the apparatus  100  is provided with means for relative x-position determination  107  of the first bar  101  along the second bar  102 , such as a scale imprinted on the second bar  102 . 
     One embodiment of the invention is illustrated by the following example describing the collection of x-y-coordinates useful for the determination of metrics related to body fat mass as known in the art, such as the F-index (Flodmark index): 
     A person P, being a child or adolescent, is lying comfortably on the back on a horizontal flat bench, being naked on the upper part of the body above the hipbone. A user places the apparatus  100 , in accordance with the description herein, so that the beam of light  109 , being a laser, is perpendicularly directed toward the side of the person P, i.e. the sagittal plane of the body. The user then registers, in any order and in accordance to the description herein, (i) the x-y-coordinates (or alternatively only the x-coordinate thereof) of the upper part of the hipbone M 1 , (ii) the x-y-coordinates (or alternatively only the x-coordinate thereof) of the lower part of the ribs M 2 , (iii) the y-coordinate M 3  (or alternatively any x-y-coordinate along the reference line L 3 ) for reference line L 3  corresponding to the intersection between the body and the bench, (iv) the x-y-coordinates (or alternatively only the y-coordinate thereof) of the uppermost point of the body M 4  of person P along vertical line L 1  being vertically extended from the middle of an imaginary line between M 1  and M 2 , and (v) the x-y-coordinates M 5  (or alternatively only the y-coordinate thereof) of extension unit  110  being placed on the breastbone of person P or of an equivalent position thereof. The vertical distance between M 5  and L 3  is related to the height of person P. The vertical distance between M 4  and L 3 , being equivalent to the distance between the horizontal lines L 2  and L 3 , is related both to the height and the body fat mass of person P. As known in the art, the relationship between the two distances is indicative of the relative body fat mass of person P at the time of measurement. 
     One embodiment of the invention is illustrated by the following example, describing the collection of x-y-coordinates useful for the determination of metrics related to body fat mass as known in the art: (i) placing the apparatus  100  with the first bar  101  extending in a vertical direction and the second and third bar  102 ,  116  extending in a horizontal direction, and the connecting bar  117  extending in a direction perpendicular to the plane defined by the first and second bars  101 ,  102 , the connecting bar  117  being connected to the first and third bars  101 ,  116 , the light emitted from the light emitting source  104  and plurality of lasers  120  or single laser  123  being directed towards the intended location of measurement of person P, (ii) placing the person P on the back on the integrated bench  112  arranged in the horizontal plane with the sagittal plane of the body facing and being parallel to the plane defined by the first bar  101  and the second bar  102 , and the coronal plane of the body being perpendicularly reachable by the plurality of beams of light  121  or said single beam of light  124 , and (iii) registering at least two limiting y-coordinates in the sagittal plane and at least two limiting z-coordinates in the coronal plane of person P. 
     According to one embodiment of the invention, apparatus  100  is provided with calculating means, such as calculating means of the control unit  111 , and with optional automatic moving means, such as means integrated with the first connecting means  105 , of first bar  101 , whereby the x-coordinate corresponding to the middle point of two user selected x-coordinates, such as M 1  and M 2 , is calculated and presented to the user, or to which the first bar  101  is automatically moved upon user selection of two x-coordinates, respectively. Said calculating means and said automatic moving means are well known in the art. 
     According to one embodiment illustrated in  FIGS. 5 and 6 , the apparatus  100  is comprising a supporting bar  128  arranged to provide spatial support for the placement of a hanging bar  129 . The hanging bar  129  is placed in a direction essentially parallel to an imaginary line along the spinal cord of a person P while facing the front side of the person P. A preferred direction of the hanging bar  129 , spatially supported in this way, is horizontally. The person P may then, during measurements, lay down comfortably in comparison to the more uncomfortable position of standing up vertically. Standing up vertically is, however, a potential applicable direction for measurements on the person P. The shape of the above described arranged supporting bar  128  may be “inverted L” (as shown in  FIG. 5 ) or any other shape, such as straight angled or curved, which is suitable for holding the hanging bar  129  in front of the center of a person P. 
     The distance between the hanging bar  129  spatially supported in this way, or any part thereof facing the person P, may be 0.05 to 3 m, preferably 0.3 to 1.5 m. 
     The supporting bar  128  may be provided with fastening means  130  for fastening onto or an external surface, e.g. a bed plate  131 . Hence, the supporting bar  128  is then not movable in relation to the bed plate  131  or a person P, when placed thereon upon measurements. Fastening means  130  include, for example, a metallic plate. The fastening means  130  may be e.g. welded, screwed or glued to the supporting bar  128 . The fastening means may be provided with holes through which it might be fastened to the bed plate  131  by employment of screws or bolts. Many other types of suitable fastening means  130  are well known in the art. 
     The bed plate  131  is arranged to be placed horizontally in the x-z-plane on a suitable bed or table with a flat surface. When so arranged, an imaginary line along the spinal cord of a person P, placed comfortably on the bed plate  131 , is essentially parallel to the x-axis. The bed plate  131  may be made of a suitable material such as glass-fibre laminate. The bed plate  131  may optionally be covered with a material or sheet which is comfortable for a person P placed thereon. This material or sheet is preferably easily cleaned to e.g. minimize the chances of spreading decease between different persons P. The bed plate  131  may optionally be provided with a head-rest pad  132 . A person P might place the head or neck thereon in order to lay down comfortably in a horizontal position on the bed plate  131 . 
     The second sliding member  133  is slidingly connected to the hanging bar  129  to allow a user to move the second sliding member  133  to a position on the hanging bar  129 , i.e. in the x-direction, as desired by the user. This movement is only limited by the effective length of the hanging bar  129 . When the second sliding member  133  has been moved to a desired x-position, manually or automatically, it is arranged to remain in that position until a user desires, either manually or by automatic means, to move it to another x-position. The second sliding member  133  is slidingly connected to the hanging bar  129  by means such as, for example, a tightening bolt, a natural friction element, or a fitting suitable for connecting a first bar to a second bar. The second sliding member  133  may be a straight bar which is fitted partly inside the hanging bar  129 . The second sliding member  133  may also be any other shape or type which allows for connection of several objects, such as light emitting devices  104  and cameras  134 , at a distance from each other onto the second sliding member  133  and along the direction of the hanging bar  129 . These objects are arranged to face the person P during measurements and to follow the movement of the second sliding member  133 . 
     One or several light emitting devices  104  are connected to the second sliding member  133  whereby they, at all times, follows the movements of the second sliding member  133 . The light emitted from each of the light emitting devices  104  may be a sheet of light  114 , traveling in the y-z-plane. One or several lines L 4  are hence projected onto the surface of the body of a person P and onto the surface adjacent to and behind the body, such as the bed plate  131 , during measurements. Each of the light emitting devices  104  are preferably arranged in such a way that the imaginary projection in the x-z-plane of each line L 4  is essentially perpendicular to an imaginary line along the spinal cord of the person P independent of the position of the second sliding member  133  on the hanging bar  129 . 
     One or several cameras  134  are connected to the second sliding member  133  whereby these, at all times, follows the movements of the second sliding member  133 . 
     The resulting reflected light from the body of a person P and from the surface adjacent to the body, corresponding to the above mentioned projected lines L 4 , is detected by the one or several cameras  134 . The one or several cameras  134  provide input data to control unit  111 , which may be a PC. A camera  134  may not be arranged in the same plane as a sheet of light  114 , but instead detecting a line L 4  from an angle, such as 10 to 80°, relative the plane of the sheet of light  114 , which is giving rise to the corresponding line L 4 . The projected line L 4  may thus be detected by the camera  134  as a curvature, when projected onto a curved body, or as a straight line, when projected on a flat surface such as the bed plate  131 . 
     The coronal and sagittal width, i.e. distances, related to the distances L 5  and L 6 , respectively, of a person P in the y-z-plane at the x-coordinate were a sheet of light  114  is resulting in a projected line L 4 , may be calculated by suitable means. Such means include for example well known picture analysis of one or several pictures taken by the corresponding camera  134 , by e.g. the control unit  111 . This picture analysis may include the determination of the coordinates for the description of the line L 4  as detected by a camera  134 . By mathematically handling of the, by a camera  134 , detected line L 4 , the distances L 5  and L 6  may be determined by taking other necessary input parameters into account, as known in the art. Input parameters for such picture analysis and mathematical handling include distances between each and one of a light emitting device  104 , the corresponding camera  134 , and the surface onto which the person P is placed. As dependant on different parameters, such as the distance of the light emitting device from the body of a person P, the coronal width will be slightly underestimated if approximated as the distance L 5  unless an error correction factor is used as an additional input parameter. Such an error correction factor is preferably determined, as known in the art, for a particular setup of the apparatus  100  and used as an additional input parameter for the calculations. 
     The relative position of the second sliding member  133  on the hanging bar  129  may be determined by suitable means, such as an electronic position sensor, to provide input data to control unit  111 . The relative positions of the one or several light emitting devices  104  and the one or several cameras  134  may be calculated, preferably by the control unit  111 , from the relative position of the second sliding member  133  and the known arrangement of the former onto the second sliding member  133 . 
     Preferably, the apparatus  100  is portable and easily dissembled and assembled so that a user easily may move it between various geographic locations for use. 
     Preferably, the components constituting the apparatus  100  are provided with smooth and comfortable surfaces which are easily cleaned in order to e.g. be comfortable for a user and a person P and to diminish the chances of spreading contagious diseases between different persons P. 
     Preferably, the apparatus  100  is provided with a back-up power source as known in the art, such a the battery of a portable PC or any other suitable battery, so that e.g. it might be used at locations where external power is not available. 
     According to one embodiment, the light emitting device is emitting light of a wavelength and intensity which is giving rice to a projected line L 4  which is narrow in width and easily detected by a camera  134 , such as a green laser. The light is preferably diffusing to a minimal extent in the skin which might otherwise give rice to broadening of the reflected line. One advantage of such an easily detected line L 4  is that it is easier to recognize and separate the line L 4  from potential back-ground interference during picture analysis and mathematical manipulation. 
     According to one embodiment, the second sliding member  133  is provided with one light emitting device  104  and one camera  134 . 
     According to one embodiment, one of either a camera  134  or a light emitting device  104  is stationary fastened, such as e.g. on the hanging bar  129 , and the other one is attached to the second sliding member  133  and thus movable together with the second sliding member  133 . 
     According to one embodiment, a camera  134  is arranged further away from the person P than a light emitting device  104  so that it might be placed closer to the same in the x-direction while still allowing measurement of at least distances L 5 . 
     According to one embodiment, the distance between a camera  134  and a light emitting device is between 0.1 to 1.5 m, preferably between 0.3 to 1 m. 
     According to one embodiment, the camera  134  is a WEB-camera or any other suitable camera provided with digital output as known in the art. 
     One embodiment of the invention is illustrated by the following example describing the collection of data comprising the coronal and sagittal width, being related to the distances L 5  and L 6 , respectively, at two different x-positions by use of an apparatus of the invention comprising one light emitting device  104  and one camera  134 , as illustrated in  FIG. 5 , which projects a line L 4  onto the body of a person P, as illustrated in  FIG. 6 : 
     A person P, being a child or adolescent, is lying comfortably on the back on the bed plate  131 , being naked on the upper part of the body above the hipbone with his or her arms pointing straight out in the z-direction. (i) A user then places the second sliding member  133 , e.g. by hand, so that the sheet of light  114 , coming from the light emitting device  104 , is drawing a line L 4  which coincides with the navel (navel position). (ii) The user then registers the corresponding picture of the camera  134  with the control unit  111 . Optionally, the user may mark this dataset with the text string “navel position” to indicate which x-position this dataset was collected at for future reference. (iii) The user then places the second sliding member  133  so that the sheet of light  114 , coming from the light emitting device  104 , is drawing a line L 4  which coincides with the highest point of the breast bone (breast bone position). Optionally, the user may mark this dataset with the text string “breast bone position” to indicate which x-position this dataset was collected at for future reference. (iv) The user then registers the corresponding picture of the camera  134  with the control unit  111 . (v) The user then employs the control unit  111  to calculate the coronal and sagittal width at each of the two x-positions (navel position and breast bone position) from the pictures that were registered with the camera  134  under “ii” and “iv” above. 
     According to one embodiment, x-positions from which data, such as the distances L 5  and L 6 , might be collected include the highest or widest point of the abdomen, the highest point of the breastbone, the hipbone and the lowest point of the rib of e.g. a person P placed vertically on the back. 
     According to one embodiment, the apparatus  100  may be used to detect irregularities or abnormalities on or within the body of the person P. Such irregularities or abnormalities include enlarged organs, e.g. the liver, a cancer, or any other irregularities or abnormalities as known in the art. 
     In the claims, the term “comprises/comprising” does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. The terms “a”, “an”, “first”, “second” etc do not preclude a plurality. Reference signs in the claims are provided merely as a clarifying example and shall not be construed as limiting the scope of the claims in any way.