1. An electric stimulation system for treating sleep apnea in a patient, comprising:
treatment means designed to treat the acoustic signal generated by the patient’s breathing and divide it into a plurality of blocks, each block corresponds to a fragment of the acoustic signal within a time interval,
said treatment means are furthermore designed to measure the strength of a plurality of blocks of the acoustic signal;
control means designed to count, in the plurality of blocks measured, the number of low strength blocks CLSB when the strength of the block is less than a strength threshold linked to breathing, TBrea, said control means furthermore being designed to determine the existence of an apnea episode when the number of low strength blocks CLSB exceeds a threshold on the number of low strength blocks TLSB,
said control means are also designed to selectively control, if there is an apnea episode, the activation of a number of electric stimulation means, designed to apply an electric signal to the submental muscles linked to the respiratory airways.
2. The system according to claim 1, wherein the blocks are generated by the treatment means, after having sampled and filtered the acoustic signal.
3. The system according to claim 1, wherein the low strength block threshold TLSB is estimated by the control means in coordination with the treatment means, with said threshold being linked to the number of blocks present in the acoustic signal generated by the patient’s breathing in a breathing interval.
4. The system according to claim 1, wherein the electric stimulation means start a temporary counter that measures the activation time, CAE, in such a way that if it exceeds a maximum activation limit TMAT, the control means deactivate the electric stimulation means independently of the existence of the apnea episode.
5. The system according to claim 4, wherein if the control means still determine the existence of the apnea episode, they increase an unsuccessful episode count (CUnsuccesful).
6. The system according to claim 4, wherein if the control means still determine the non-existence of an apnea episode, they increase a successful episodes count, CSuccessful.
7. The system according to claim 4, wherein the control means adjust the value of the frequency andor intensity of the electrical signal generated by the electric stimulation means, in such a way that:
the intensity andor frequency is decreased within a range depending on the value of the CSuccessful count and
the intensity andor frequency is increased within a range depending on the value of the CUnsuccesful count.
8. The system according to claim 1, wherein the treatment means are configured to receive the signal from a microphone designed to capture the acoustic signal generated by the patient during breathing.
9. The system according to claim 1, wherein it furthermore comprises storage means, designed to store at least one of the following values:
TBrea, TLSB, CAE, TMAT, CUnsuccessful, CSuccessful, CLSB, maximum and minimum frequency range for the electrical signal applied, maximum and minimum intensity range for the electrical signal applied.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A projection device, comprising:
an image source unit configured to emit light carrying an image having a rectangular shape;
a first projecting optical system configured to form an intermediate image carried by the light emitted by the image source unit, the intermediate image having a trapezoidal shape due to trapezoidal distortion;
a second projecting optical system; and
an intermediate optical system configured to lead light from the first projecting optical system to the second projecting optical system, the second projecting optical system being configured to obliquely project light deflected by the intermediate optical system to a screen of the projection device, the image projected on the screen having a shape similar to the image provided by the image source,
wherein each of the first projecting optical system and the second projecting optical system is configured to be substantially telecentric toward the intermediate image.
2. The projection device according to claim 1,
wherein the first projecting optical system is configured such that, on a plane including the optical axes of he first projecting optical system and the second projecting optical system, a first angular difference between an angle formed between a chief ray of light emitted from a lower end of the image source and an optical axis of the first projecting optical system and an angle formed between a chief ray of light emitted from an upper end of the image source and the optical axis of the first projecting optical system is smaller than a convergence angle of a light beam emitted from a central portion of the image source and incident on the intermediate optical system as a converging beam via the first projecting optical system, and
wherein the second projecting optical system is configured such that, on a plane including the optical axes of the first projecting optical system and the second projecting optical system, a second angular difference between an angle formed between the chief ray of light emitted from the lower end of the image source and an optical axis of the second projecting optical system and an angle formed between the chief ray of light emitted from the upper end of the image source and the optical axis of the second projecting optical system is smaller than a divergence angle of a light beam emitted from a central portion of the image source and then emerged from the intermediate optical system as a diverging beam.
3. The projection device according to claim 2,
wherein the screen is tilted by a predetermined tilt angle with respect to a plane perpendicular to the optical axis of the second projecting optical system, and
wherein either of the first angular difference and the second angular difference is equal to or greater than \u03b8M, where \u03b8 is an absolute value of the predetermined tilt angel, and M is a projection magnification of the projection device.
4. The projection device according to claim 1,
wherein the intermediate optical system includes at least one prism.
5. The projection device according to claim 1,
wherein the intermediate optical system is configured to compensate for chromatic aberration.
6. The projection device according to claim 1,
wherein the intermediate optical system comprises multiple prisms, at least one of the multiple prisms being formed of material having different Abbe’s number than other prisms.