[ 0027 ] fig1 shows the control of the first embodiment , a block diagram of the connection of the pillow height control system employing the present invention . the body position signal , which is generated by the body sleeping position sensor 101 measuring the body sleeping position , is connected to the pillow height control device 102 . the said pillow height control device 102 compares the said body position signal with the desired pillow height for the said body sleeping position and drives the platform 103 that holds the cushioning material of the pillow up or down until the said platform 103 reaches the desired height . the said desired height is detected by the upper and lower position switches 104 for logic on - off control , or the analog platform height sensor 105 for analog proportional control . the said platform 103 can be driven by electromechanical device such as electric motor and gears assembly , if can also be driven by electromechanical device such as electric motor and air pump assembly . any suitable device that can raise the said platform may be used . the upper and lower position switches 104 govern the height of the said platform 103 . alternately , an analog platform height sensor 105 can also be used to adjust continuously the height to a desired position that is controlled by an external control device 106 . any suitable device that can control the height of the platform may be used . the external control device 106 provides a mean to set the upper and lower height positions . the said external control device 106 provides height equivalent references for the said pillow height control device 102 to control the said platform 103 to the desired heights . if the analog position sensor 105 uses resistance as the height equivalent physical quantity , the said height equivalent references are the resistance physical quantities . [ 0032 ] fig2 shows the construction of first embodiment employing the present invention . in this embodiment , a rigid box with a controllable height is employed such that it can be placed beneath a pillow , adjusting the height of the said rigid box effectively control the height of a pillow that supports the sleeper &# 39 ; s head . the body position signal from the body sleeping position sensor described in fig4 is a logical signal indicates whether the sleeper is in the symmetric or asymmetric position . upon receiving the signal , the pillow height control device drives the electromechanical device 201 in turn moves the platform 202 that holds the cushioning material supporting the sleeper &# 39 ; s head to the desired height . the electromechanical device is an electric motor gearbox assembly 201 that couples to the main screw 200 . the electric motor turning in one direction raises the platform 202 while turning in the opposite direction lowers the platform 202 . the height of the said platform is reflected by the horizontal displacement of a block 205 that is connected to the top of the said platform 202 by a non - stretchable wire 206 via a pulley 207 that changes the axis of movement from vertical to horizontal . the other end of the said block 205 is connected to a fixture by a spring 208 that provides tension to the wire 206 . the horizontal movement of the said block reflects the height of the said platform 202 . the upper position switch 203 and the lower position switch 204 are placed along the axis of movement of the said block 205 . the said block 205 moves when the height of the said platform 202 changes , it triggers the upper position switch 203 or the lower position switch 204 when the position of the said block reaches the contact points of the said upper position switch 203 and lower position switch 204 . setting the horizontal position of the upper position switch 203 and the lower position switch 204 governs the movement of the said platform 202 to the desired positions . the lower position corresponds to the minimized stress position for sleeper in his symmetric sleeping position . the higher position corresponds to the minimized stress position for sleeper in his asymmetric sleeping position . [ 0040 ] fig2 a shows the construction of the analog platform height sensor assembly for first embodiment employing the present invention . the wire 206 is coupled to the moving arm of the variable resistance 210 . for rotational variable resistance device , a few turns of wire 206 is wrapped around the rotating arms of the variable resistance . for linear variable resistance device , the wire 206 is attached to the linear moving arm of the variable resistance . the movement of the moving arms of the variable resistance 210 corresponds to the up or down movement of the said platform 202 . the relative resistance of the said variable resistance 210 reflects the relative height of the said platform 202 . [ 0042 ] fig3 shows the construction of the second embodiment employing the present invention . in this embodiment , all the material used are soft and safety so that it is suitable for putting inside a pillow . the electromechanical device is an electric air pump that pumps air into or out of the air bags 301 through the air tube 308 . the air bags 301 consists of many equal compartments that are connected together , each compartment provides equal horizontal supports to the platform 302 , which may be the upper body of the air bags 301 if a rigid cushioning material is used . a non - stretchable wire 306 is connected to the top of the said platform 302 , a pulley 307 changes the axis of movement of the wire 306 from vertical to horizontal . the said wire 306 is extended to a platform height sensor assembly described in fig2 a through a fixed length conduit 309 such that the displacement of the said wire 306 relative to the conduit 309 reflects the height of the said platform . the movement of the moving arms of the said variable resistance 210 as described in fig2 a corresponds to the up or down movement of the said platform 302 . the relative resistance of the said variable resistance 310 reflects the relative height of the said platform 302 . the connections to the external device are an air tube 308 and a conduit 309 , which can also be constructed by soft and safety materials . the platform height sensor assembly described in fig2 a and the air pump can be placed inside an external device . [ 0049 ] fig4 a shows a diagram of the body sleeping position sensor that uses area physical quantity . the said body sleeping position sensor 401 is a bag with many interconnected compartments 403 of equal volume . each compartment holds equal volume of air or fluid . the interconnections between compartments are permeable to air and fluid such that when the compartment 403 is totally compressed by the human body , the air or fluid contained in the compartment 403 is displaced to the next compartments and will not be blocked . by placing the said body sleeping position sensor 401 parallel to the pillow and perpendicular to sleeper &# 39 ; s vertebra , more compartments 403 will be compressed when the sleeper is in the symmetric sleeping position . the said body sleeping positions sensor 401 allows using either air or fluid as the media to reflect the change in area physical quantity . if air is used , the change of air pressure measured at the nozzle 401 is proportional to the change in area . if fluid is used , the volume of the in - compressible fluid displaced from the nozzle 401 is proportional to the change in area . [ 0052 ] fig4 b shows a diagram of the body sleeping position sensor that uses temperature physical quantity . the said body sleeping position sensor 410 is pad with many thermo - sensitive devices 411 connected in series . the said thermo - sensitive device may be an array of thermocouples that develops voltage across the bi - metal junctions when exposed to different temperatures . the said change of voltage can be measured at the terminal 412 . the change of voltage developed across the array of thermocouples connected in series is proportional to the change of area of the sensor that makes physical contact with the sleeper body . the said thermo - sensitive devices may be an array of thermistors that changes its resistance when exposed to different temperatures . the said change of resistance can be measured at the terminal 412 . the change of resistance across the array of thermistors connected in series is proportional to the change of area of the sensor that makes physical contact with the sleeper body .
a pillow height control system includes a pillow height control device adapted to receive a body position signal that is generated by the body sleeping position sensor . the pillow control device is placed between the bed and the cushioning material that supports the sleeper &# 39 ; s head . the device controls an electromechanical device that moves a platform that supports the cushioning material up or down to a position accurate enough to minimize the stress on the neck and shoulder . the fact that sleeper changes sleeping position from time to time several times during his sleep fails many designs . in preferred embodiments , user can adjust the optimum heights of the pillow for different sleeping positions .