(Color online) (a) A schematic diagram of the principle of the two light source single detector system operating at with phase sensitive detection and LED indication of phase signal. (b) Circuit details of a higher gain circuit containing stabilized oscillator and sufficient gain and millivolt output from the phase detecting circuit to give the millivolt sensitivity values indicated by the figures attached.
(Color online) Present state of miniaturization of Instrument 1 with PC board construction (right) (hand held breast cancer detector) compared to commercial glucosometer (Accu-Chek®) (left). The LEDs and detector are at bottom of Instrument 1.
A dual-wavelength handheld device in which is at and is at operating at 0.3 and with signal separation in and and demodulation as in previous figure to give a localization The signals and are processed to give an indication of angiogenesis and hypermetabolism. The LED display is not shown but is similar to that of Fig. 6.
(Color online) Scanning test of Instrument 1 on a solid model with embedded absorbing object below the surface: (a) scan along the 0° axis, and (b) scan along the 45° axis. The electronics are arranged so that away from the target the LED indicator will change color and∕or the pitch of the tone may change. The principle of the amplitude of the two source, one detector system is illustrated where we have (red trace) the track of the device together with the signal amplitude going from a very low value, a long distance from the absorbing object, increasing to a negative maximum and to zero again as the object is crossed, leading to a second maximum and again to zero. If the scanner is then turned through 45° and the second scan is made, the same max-to-zero signal change is observed and the intersection of the two is within of that of the hidden object. These scans are described below for locating a breast cancer (see Figs. 5 and 7).
(Color online) Illustrating source-detector separation scanned across subsurface sphere filled with in , , . The scanning profile under conditions similar to that of Fig. 4 except that the scan is started at distance from the subsurface object and scanned to past the subsurface object. Again, log coordinates are used for the signal display. Unbalanced signals from the hidden object are obtained as shown at distance.
(Color online) Illustration of the effect of depth of the submerged object on the sensitivity in detection. The system gives a maximum signal at from the subsurface object at depth.
(Color online) Illustrating the sensitivity profile for the two source, single detector system at separation scanned across a subsurface sphere filled with , , wavelength . The curve displays the difference signal while scanning across the above-mentioned object from . Log coordinates are used for the signal display. An experimental test of the object detection sensitivity of the circuit of figure above. Two sources at spaced from the detector and manually scanned at a distance from the submerged object indicated by the abscissa. The ordinate indicates the millivolt signal as obtained at these distances, the scanner being close enough to give a full scale imbalance at from the hidden object.
Article metrics loading...
Full text loading...