an inclination detector is denoted overall by the reference 10 in fig1 . the inclination detector 10 comprises a housing 1 a , which is used as a displacement guide for a weight 3 a that can move along the displacement guide . an electronics unit 23 for acquisition and processing is joined to the detector 10 and to an alarm generator 25 . according to the invention , the detector comprises an electro - optical transmitter 7 a and an electro - optical receiver 7 b for respectively transmitting and receiving an optical beam 7 c . the transmitter and the receiver are arranged , with respect to the housing 1 a , so that the weight 3 a blocks the optical beam 7 c when it moves along the housing 1 a as a function of the inclination of the latter . the electro - optical transmitter and the electro - optical receiver consist , for example , of a photodiode 7 a and a phototransistor 7 b . they are arranged inside the housing 1 a , at one of its ends . the weight 3 a also moves inside the housing , which is closed by a lid 1 b . a supply unit , for example a cell or battery , is provided for the electro - optical transmitter and the electro - optical receiver . in fig1 α denotes the inclination of the detector with respect to the local vertical v , which is considered as the reference direction . when the detector reaches , downwards with respect to the vertical v , a threshold inclination denoted by αsb in fig1 the weight 3 a moves by sliding inside the housing 1 a towards the end where the electro - optical emitter 7 a and the electro - optical receiver 7 b are arranged , until it blocks the optical beam 7 c . when the optical beam 7 c is blocked , the electro - optical receiver delivers an electrical signal , indicating crossing of the low threshold , to the electronics unit 23 for acquisition and processing , which activates the alarm generator 25 . the generation of the alarm signifies that the downward inclination αsb has been exceeded by the detector . if the detector is subsequently inclined upwards , it reaches a threshold inclination denoted by αsh in fig1 at which the weight 3 a moves towards the end of the housing opposite the one where the electro - optical transmitter and the electro - optical receiver are arranged . when the optical beam 7 c is received , the receiver 7 b delivers an electrical signal , indicating crossing of the high threshold , to the electronics unit 23 for acquisition and processing , which deactivates the alarm generator 25 . the end the alarm signifies that the upwards inclination αsh has been exceeded by the detector . it is important to note that the blocking of the optical beam may also deactivate the alarm generator , and hence end the alarm . in order to activate the alarm generator , and hence generate the alarm , it is sufficient for the weight to move , under the effect of the inclination of the detector , towards the end opposite the one where the electro - optical transmitter and the electro - optical receiver are arranged . this mode of operation promotes relatively rapid generation of the alarm compared with the time for moving the weight inside the housing . the mode of operation described in the previous paragraph favours rapid ending of the alarm . in the exemplary embodiment in fig1 the electro - optical transmitter 7 a and the electro - optical receiver 7 b are separated from one another so as to permit the insertion of a tab 3 b , which is mounted on the weight 3 a so as to project from it , and which forms a shutter member for the optical beam 7 c . the weight 3 a and the housing 1 a are both flat , in order to advantageously reduce the thickness of the detector . preferably , the weight is made from a plastic material in order to decrease the weight of the detector . a further option is to make the housing from plastic material as well . according to a particular embodiment of the invention ( see fig2 and 3 ), the detector comprises channels 13 which allow a gas , for example air , to flow in the housing 1 a when the weight 3 a is moving inside it . these channels extend along the housing , parallel to the direction of movement of the weight . preferably , bars 15 are inserted then immobilised inside the channels 13 in order to adjust the flow of the gas in the housing 1 a . by this arrangement , the speed of the weight is controlled by adjusting the air flow between the parts of the housing which are located in front of the weight and behind it , in its direction of movement . the adjustment is carried out by inserting then immobilising the bars 15 in the channels 13 over different insertion lengths . the adjustment of the air flow with the aid of the bars 15 , which are inserted into the channels 13 , also makes it possible to damp the vibrations of the weight , hence contributing to increasing the reliability of the detector . according to another particular embodiment of the invention , which can also be seen in fig2 and 3 , the detector comprises wedges 17 for adjusting the displacement travel of the weight 3 a along the housing 1 a . in the example of fig2 the wedges 17 are inserted then immobilised in the housing 1 a , at the end opposite the one where the electro - optical transmitter 7 a and the electro - optical receiver 7 b are arranged , and perpendicularly to the direction of movement of the weight 3 a . the displacement travel of the weight is adjusted by inserting one or other of the wedges 17 into the housing 1 a . “\ l 3the wedges 17 make it possible to adjust the crossing angle αsb of the low inclination threshold with respect to the reference direction , and consequently to adapt the angular range of the detector . it should be noted that , when the mobile member is in the form of a ball , it is possible to achieve lower inclination - threshold crossing values compared with a mobile member having the form of a flat weight . a device designed for generating an alarm as a function of the inclination of the body , or of a part of the body , of an individual comprises ( see fig4 a and 4 b ) an undergarment 21 intended to be worn by the individual , and one or more inclination detectors 10 according to the invention , which are each fixed on the undergarment and are joined to an alarm generator 25 via an electronics unit 23 for acquisition and processing . according to the invention , the mobile member 3 a as well as the electro - optical transmitter 7 a and the electro - optical receiver 7 b are arranged in a leaktight displacement guide 1 a and 1 b , in order to make it possible to wash the undergarment 21 without removing the detectors 10 . the undergarment 21 is made of a technical fabric which promotes the removal of sweat , and which permits good circulation of air between the body and the external environment . the detectors 10 are , for example , stitched into a lining of the undergarment , so that they are not in direct contact with the skin . the damping of the vibrations of the weight , which results from the adjustment of the air flow with the aid of the bars , makes it advantageously possible not to generate an alarm when the user performs a movement , for example jumping or running , which by itself does not lead to the crossing of a threshold inclination . furthermore , the wedges make it possible to adapt the angular range of the detector to various human morphology types and to different types of movement to be monitored . preferably , the alarm generator 25 is arranged in a leaktight housing and is fixed to the undergarment 21 , as can be seen in fig4 a . likewise , the electronics unit 23 joined to the alarm generator 25 , and also joined to each detector 10 , is arranged in a leaktight housing fixed to the undergarment 21 . as can be seen in fig5 the housing 11 contains both the electronics unit 23 for acquisition and processing and the alarm generator 25 , for example a vibrator . it is , for example , made from a plastic material and arranged in an outside pocket stitched onto the undergarment . the electronics unit 23 is connected to the electro - optical transmitter 7 a and the electro - optical receiver 7 b by connecting wires 9 , in order to acquire signals indicating the crossing of inclination thresholds αsb or αsh delivered by the electro - optical receiver 7 b of each detector 10 . the electronics unit processes these crossing signals so as to activate or deactivate the alarm generator 25 , and hence to generate or stop an alarm . the housing 11 also comprises a display 27 joined to a counter ( not shown ) in order to display the number of alarm generations during a given period of using the undergarment . a battery or a cell 29 is accommodated in the housing 11 for independent supply of its elements . advantageously , this energy source is used to supply the electro - optical transmitter and the electro - optical receiver of the detector or detectors fixed on the undergarment . the outside pocket of the undergarment facilitates access to the housing 11 in order to replace the cell 29 . the vibrator preferably makes it possible to generate the alarm in the form of a touch sensation for the user . a further option is to use a sound generator as the alarm generator , although the touch alarm is more discreet than the sound alarm . in the exemplary embodiment illustrated by fig4 a and 4 b , the undergarment comprises four inclination detectors . an upper detector is fixed on the undergarment in order to occupy a lateral position under the armpit for the individual . this detector makes it possible to monitor the anterior flexion of the torso . a lower detector is fixed so as to occupy a position on the pelvis for the individual , at the top of the iliac crest . this detector makes it possible to monitor the retroversions of the pelvis in a seated position . likewise , as can be seen in fig4 b , a left - hand detector and a right - hand detector for the spinal column are fixed on the undergarment in order to occupy a position level with the supraspinous fossae of the scapula for the individual . these two detectors make it possible to monitor the lateral inflections of the torso . combined use of the anterior flexion detector with one or other of the lateral inflection detectors makes it possible to monitor the rotations / flexions of the torso . the acquisition and processing unit 23 advantageously makes it possible to filter out repetitive signals indicating crossing of the inclination thresholds αsb or αsh , which are generated when the individual performs movements such as fast walking or running , since these movements are not in themselves unsuitable . filtering out the signals makes it possible to avoid generation of an alarm . it should be noted that this filtering is additional to the mechanical filtering of the vibrations of the weight , which is carried out by the bars 15 . one option is to fix the connecting wires 9 on the undergarment 21 , for example in a lining . a further option is to connect the electronics unit 23 to the inclination detectors 10 by wireless connections . more particularly , the electro - optical transmitter 7 a and the electro - optical receiver 7 b of a detector , as well as the alarm generator 25 and the acquisition and processing unit 23 , each have an integrated supply and means for communicating by electromagnetic waves .
the invention concerns an inclination detector comprising a displacement guide , a member mobile along the displacement guide , and means cooperating with the mobile member to control an alarm generator based on the inclination of the displacement guide . the invention is characterised in that said means comprise electrooptical transmitter and receiver for respectively transmitting and receiving an optical beam so as to activate or deactivate the alarm generator when the mobile member obstructs the optical beam by moving along the displacement guide . preferably , the mobile member as well as the electrooptical transmitter and receiver are arranged in a sealed displacement guide . the inventive detector is fixed to an undergarment enabling a user to acquire and integrate a movement adapted to the spine .