System and method for analyzing tonosignals
AssigneeCavitron Corporation
InventorCharles W. Ragsdale
Life of this patent
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Abstract
A system and method analyzes tonosignals and other electrical signals representative of force-displacement information from applanating probes such as those initially to determine the presence of an acceptable waveform or tonosignal. Once an acceptable waveform is found, that waveform is analyzed further to locate the point of applanation. The level of the waveform at that point may be converted to a digital signal and displayed to indicate the pressure within the eye or other objects to which the probe is applied.
Claims24
In a method of analyzing an electrical signal representative of force-displacement information from an applanating probe, the steps of:
- monitoring the level of said signal and the rate of change of said level to detect occurrence of a waveform of predetermined character at a predetermined time, further monitoring the slope of said waveform to detect the occurrence of a predetermined change in said slope after detection of the occurrence of said waveform of predetermined character, and providing an output signal corresponding substantially to the level of said signal at the time of said change in slope.
In a system for analyzing an electrical signal representative of force-displacement information from an applanating probe:
- means for monitoring the level of said signal and the rate of change of said level to detect the occurrence of a waveform of predetermined character at a predetermined time, means for further monitoring the slope of said waveform to detect the occurrence of a predetermined change in said slope after detection of the occurrence of said waveform of predetermined character, and means for providing an output signal corresponding substantially to the level of said signal at the time of said change in slope.
In a method of analyzing an electrical probe signal representative of force-displacement information from an applanating probe, the steps of:
- monitoring the level of said probe signal and the rate of change of said level to detect the occurrence of a waveform of predetermined character within a predetermined period of time, storing a first output signal corresponding to the level of the probe signal upon detection of said waveform of predetermined character, monitoring the slope of said waveform to detect the occurrence of a predetermined change in said slope, storing a second output signal corresponding substantially to the level of said waveform upon detection of said change in slope, and providing a utilization signal corresponding to the last stored of said first and second output signals.
In a system for analyzing an electrical probe signal representative of force-displacement information from an applanating probe:
- means for monitoring the level of said probe signal and the rate of change of said level to detect the occurrence of a waveform of predetermined character within a predetermined period of time, means for storing a first output signal corresponding to the level of the probe signal upon detection of said waveform of predetermined character, means for monitoring the slope of said waveform to detect the occurrence of a predetermined change in said slope, means for storing a second output signal corresponding substantially to the level of said waveform upon detection of said change in slope, and means for providing a utilization signal corresponding to the last stored of said first and second output signals.
In a method of analyzing an electrical probe signal representative of force-displacement information from an applanating probe, the steps of:
- A. monitoring said probe signal to determine whether the following conditions are met:
- 1. Said probe signal reaches a predetermined threshold level at least a predetermined minimum time after any previous reaching of said level,
- 2. The level of said probe signal changes at a positive rate which decreases within a predetermined time window which commences a predetermined time after said threshold level is reached,
- 3. The decreased rate of change continues for a predetermined period of time within said time window;
- and
- B. in the event that all of said conditions are met, providing an output signal corresponding to the level of said probe signal at the time said conditions are met.
In a system for analyzing an electrical probe signal representative of force-displacement information from an applanating probe:
- A. means for monitoring said probe signal to determine whether the following conditions are satisfied:
- 1. Said probe signal reaches a predetermined threshold level at least a predetermined minimum time after any previous reaching of said level,
- 2. The level of the probe signal changes at a positive rate which decreases within a predetermined time window which commences a predetermined time after said threshold level is reached,
- 3. The decreased rate of change continues for a predetermined period of time within said time window;
- and
- B. means active upon satisfaction of all of said conditions for providing an output signal corresponding to the level of said probe signal at the time said conditions are satisfied.
Dependencies are inferred from the claim text.