1. Apparatus to be worn on the body for the production and detection of fluorescence at or below a skin surface, said apparatus comprising:
a light source for directing fluorescence excitation light along a light path extending over said skin surface;
a reflector having a three dimensionally curved, shell-like light reflecting interface positioned to receive light from the light source passing over said skin surface along a portion of said light path and to reflect said light transversely with respect to said portion of the light path so as to focus said light on an illumination zone at or below said skin surface for stimulation of fluorescence at said zone, and to collect fluorescence light emitted at said zone and to reflect and at least partially collimate said light to pass back along said portion of the light path;
a detector for receiving said light emitted as fluorescence after reflection at said interface, and a housing containing the light source, detector and reflector, which housing is configured to be worn on the body, wherein said reflector interface substantially has the form of a partial paraboloid, aspheric, toroidal, or biconic surface, and wherein said reflector interface is defined by an equation
Z
=
cr
2
1
+
1
–
(
1
+
k
)
\u2062
c
2
\u2062
r
2
wherein:
c is from 0.07 to 0.5 and k is from \u22121.5 to \u22120.7. where z is the \u201csag\u201d of z-coordinate along the rotational axis, c is the curvature (the reciprocal of the radius R), k is the conical constant and r is the radial coordinate.
2. Apparatus as claimed in claim 1, further comprising a beam splitter reflecting light emitted by said light source to pass to said reflector and receiving fluorescence light from said reflector and passing said fluorescence light to said detector.
3. Apparatus as claimed in claim 2, wherein said reflector, light source and detector are arranged in a generally coplanar manner and said beam splitter has a planar reflective interface that lies in a plane orthogonal to the co-planarity of the reflector, light source and detector.
4. Apparatus as claimed in claim 1, further comprising an excitation filter selecting an excitation wavelength from the light emitted by the light source to pass to said reflector.
5. Apparatus as claimed in claim 1, further comprising an emission filter selecting an emitted fluorescence wavelength to pass to said detector.
6. Apparatus as claimed in claim 1, comprising a lens or a second reflector focusing fluorescence light on said detector.
7. Apparatus as claimed in claim 1, wherein said reflector interface includes that part of a paraboloid, aspheric, toroidal, or biconic surface that is generated by the cutting of a paraboloid, aspheric, toroidal, or biconic surface by a right circular cylinder erected centred on the illumination zone.
8. Apparatus as claimed in claim 1, wherein said reflector interface substantially has the form of a part of a half paraboloid.
9. Apparatus as claimed in claim 1, further including a wherein the housing containing the light source, reflector and detector has a base surface containing a window for passing excitation light out of the housing and receiving fluorescence light into the housing and being for engagement in use against the said skin surface at or below which said fluorescence occurs.
10. Apparatus as claimed in claim 9, wherein said light path makes an angle of no more than 10 degrees with a plane defined by said base surface.
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 method of providing network access across a shared communications medium between competing users, with a first plurality of users being grouped within a first class and a second plurality of different users being grouped within a second class, comprising the steps of:
determining allowances of network access for a first time interval and allocating network access to each user within the class for the first time interval;
providing network access to each user during the first time interval such that no user receives more network access than that user’s allowance and no class receives more collective network access than that class’ network allowance;
monitoring network access usage by each user;
forecasting network access usage by each user class during a future time interval based on said step monitoring network access usage by each user; and
providing network access to each user during the future time interval such that no user receives more network access than that user’s allowance and no class receives more collective forecasted network access than that class’ forecasted allowance.
2. The method of claim 1, wherein for at least one class, the allocated network access for the first time interval for each user differs from the forecasted network access for the future time interval for that user.
3. The method of claim 1, wherein the collective network access allocated to each class for the first time interval differs from the collective network access forecasted to each class for the future time interval.
4. The method of claim 1, further comprising the step of tracking network access usage for each user class.
5. The method of claim 1, further comprising prioritizing the user classes for allocating network access.
6. The method of claim 1, further comprising prioritizing the users for allocating network access.
7. The method of claim 1, wherein said step of forecasting comprises summing within each class a forecasted network access usage of each user.
8. The method of claim 1, wherein said step of forecasting network access usage of each user comprises applying an adaptive-response-rate single exponential smoothing function and a Holt-Winters’ seasonal exponential smoothing function to said monitored network access usages of each user.
9. A system of providing network access across a shared communications medium between competing users, with a first plurality of users being grouped within a first class and a second plurality of different users being grouped within a second class, the system comprising:
a determining component configured to determine allowances of network access for a first time interval and allocating network access to each user within the class for the first time interval;
a providing component configured to provide network access to each user during the first time interval such that no user receives more network access than that user’s allowance and no class receives more collective network access than that class’ network allowance;
a monitoring component configured to monitor network access usage by each user;
a forecasting component configured to forecast network access usage by each user class during a future time interval based on said step monitoring network access usage by each user; and
a providing component configured to provide network access to each user during the future time interval such that no user receives more network access than that user’s allowance and no class receives more collective forecasted network access than that class’ forecasted allowance.
10. The system of claim 9, wherein for at least one class, the allocated network access for the first time interval for each user differs from the forecasted network access for the future time interval for that user.
11. The system of claim 9, wherein the collective network access allocated to each class for the first time interval differs from the collective network access forecasted to each class for the future time interval.
12. The system of claim 9, further comprising a tracking component configured to track network access usage for each user class.
13. The system of claim 9, further comprising a first prioritizing component configured to prioritize the user classes for allocating network access.
14. The system of claim 9, further comprising a second prioritizing component configured to prioritize the users for allocating network access.
15. The system of claim 9, wherein the forecasting component is further configured to sum within each class a forecasted network access usage of each user.
16. The system of claim 9, wherein the forecasting component is further configured to apply an adaptive-response-rate single exponential smoothing function and a Holt-Winters’ seasonal exponential smoothing function to said monitored network access usages of each user.
17. A computer readable medium of providing network access across a shared communications medium between competing users, with a first plurality of users being grouped within a first class and a second plurality of different users being grouped within a second class, the computer readable medium comprising:
determining logic configured to determine allowances of network access for a first time interval and allocating network access to each user within the class for the first time interval;
providing logic configured to provide network access to each user during the first time interval such that no user receives more network access than that user’s allowance and no class receives more collective network access than that class’ network allowance;
monitoring logic configured to monitor network access usage by each user;
forecasting logic configured to forecast network access usage by each user class during a future time interval based on said step monitoring network access usage by each user; and
providing logic configured to provide network access to each user during the future time interval such that no user receives more network access than that user’s allowance and no class receives more collective forecasted network access than that class’ forecasted allowance.
18. The computer readable medium of claim 17, further comprising a prioritizing logic configured to prioritize the user classes for allocating network access.
19. The computer readable medium of claim 17, wherein the forecasting logic is further configured to sum within each class a forecasted network access usage of each user.
20. The computer readable medium of claim 17, wherein the forecasting logic is further configured to apply an adaptive-response-rate single exponential smoothing function and a Holt-Winters’ seasonal exponential smoothing function to said monitored network access usages of each user.