Waveform visualization tool for facilitating medical diagnosis

Abstract

A tool for facilitating medical diagnosis is disclosed herein, including an ultrasound device configured to collect ultrasound data from a patient, a display device, and a processing circuit configured to generate a cerebral blood flow velocity (CBFV) waveform based on the ultrasound data, determine morphology indicators identifying attributes of the CBFV waveform, and configure the display device to display the CBFV waveform and the morphology indicators.

1 . A tool for identifying a waveform pulse of a first signal representing a physiological characteristic of a subject, comprising:
 an ultrasound device configured to receive and collect the first signal representing the physiological characteristic of the subject; and   a processing circuit configured to:
 generate a second signal based on the first signal, the second signal representing change within the first signal; 
 identify a sharp upslope of the first signal based on the second signal; 
 determine a search window along the first signal that begins around the identified sharp upslope; and 
 identify, within the search window, an onset of the waveform pulse. 
   
     
     
         2 . The tool of  claim 1 , wherein the second signal reflects a net change within the first signal over a predetermined time interval. 
     
     
         3 . The tool of  claim 1 , wherein the second signal is a slope sum function (SSF) signal of the first signal. 
     
     
         4 . (canceled) 
     
     
         5 . The tool of  claim 1 , wherein the processing circuit is configured to determine the search window along the first signal by:
 determining a threshold;   detecting a crossing point between a location along the second signal and the threshold, the crossing point corresponding to a first time value; and   defining the search window as being between the first time value and a second time value prior to the first time value.   
     
     
         6 . The tool of  claim 5 , wherein the second time value corresponds to a feature of a previously detected waveform pulse of the first signal that immediately precedes the first time value. 
     
     
         7 . The tool of  claim 6 , wherein the feature comprises a peak of the previously detected waveform pulse. 
     
     
         8 . The tool of  claim 5 , wherein the second time value precedes the first time value by a predetermined time interval. 
     
     
         9 . The tool of  claim 5 , wherein the processing circuit is configured to determine the threshold based on a predetermined number of preceding peaks of the second signal. 
     
     
         10 . The tool of  claim 9 , wherein the threshold is a percentage of an average of the predetermined number of the preceding peaks of the second signal. 
     
     
         11 . The tool of  claim 5 , wherein the processing circuit is configured to determine the threshold based on all preceding peaks in the second signal that exceed a peak threshold. 
     
     
         12 . The tool of  claim 11 , wherein the peak threshold is a multiple of an average of the second signal. 
     
     
         13 . The tool of  claim 5 , wherein the processing circuit is further configured to:
 apply a refractory time period starting at the first time value; and   refrain from detecting new threshold crossing points until after the refractory time period.   
     
     
         14 . The tool of  claim 5 , wherein the processing circuit is configured to identify the onset by:
 identifying one or more valleys of the first signal within the search window; and   selecting one of the valleys as the onset.   
     
     
         15 . The tool of  claim 14 , wherein the processing circuit is configured to select the one of the valleys as the onset by determining that the selected one of the valleys is a closest valley of the one or more valleys to the first time value. 
     
     
         16 . The tool of  claim 15 , wherein the processing circuit is further configured to select the one of the valleys as the onset by determining that a peak value of a pulse of the first signal minus a value of the selected one of the valleys is greater or equal to a factor multiplied by a peak value of the second signal. 
     
     
         17 . The tool of  claim 1 , wherein the processing circuit is further configured to:
 determine corresponding length values of a plurality of identified waveform pulses of the first signal;   perform a comparison of a first one of the determined length values to a reference value; and   detect whether the first one of the determined length value is a long waveform pulse or a short waveform pulse based on the comparison.   
     
     
         18 . The tool of  claim 17 , wherein the processing circuit is further configured to determine the reference value based on the determined length values. 
     
     
         19 . The tool of  claim 17 , wherein the reference value is a median value of the determined length values. 
     
     
         20 . The tool of  claim 17 , wherein the processing circuit is further configured to, in response to detecting the long waveform pulse, identify another onset within the long waveform pulse. 
     
     
         21 . The tool of  claim 17 , wherein the processing circuit is further configured to, in response to determining the short waveform pulse, combine the short waveform pulse with an adjacent waveform pulse to the short waveform pulse. 
     
     
         22 . The tool of  claim 1 , wherein the first signal comprises a continuous cerebral blood flow velocity (CBFV) signal from the subject. 
     
     
         23 . The tool of  claim 1 , wherein the processing circuit is further configured to adjust at least one of a position or an orientation of the ultrasound device based on the waveform pulse. 
     
     
         24 . (canceled) 
     
     
         25 . The tool of  claim 1 , further comprising a display device, wherein the processing circuit is further configured to display the waveform pulse at the display device. 
     
     
         26 . The tool of  claim 25 , wherein the processing circuit is further configured to determine a morphology indicator configured to visually indicate an attribute of the waveform pulse and display the morphology indicator at the display device. 
     
     
         27 . The tool of  claim 26 , wherein the morphology indicator indicates at least one of a first peak of the waveform pulse, a second peak of the waveform pulse, or a distance between the first peak and the second peak. 
     
     
         28 . The tool of  claim 1 , wherein the processing circuit is further configured to:
 receive a third signal from at least one of an electrocardiogram device, a pulse oximetry device, or a heartrate monitor; and   confirm that the identified waveform pulse is accurate based on the third signal.   
     
     
         29 . A method for identifying a waveform pulse of a first signal representing a physiological characteristic of a subject, comprising:
 receiving and collecting the first signal representing the physiological characteristic of the subject;   generating a second signal based on the first signal, the second signal representing change within the first signal;   identifying a sharp upslope of the first signal based on the second signal;   determining a search window along the first signal that begins around the identified sharp upslope; and   identifying, within the search window, an onset of the waveform pulse.   
     
     
         30 . A non-transitory processor-readable medium storing processor-readable instructions such that, when executed, causes a processor to identify a waveform pulse of a first signal representing a physiological characteristic of a subject by:
 receiving and collecting the first signal representing the physiological characteristic of the subject;   generating a second signal based on the first signal, the second signal representing change within the first signal;   identifying a sharp upslope of the first signal based on the second signal;   determining a search window along the first signal that begins around the identified sharp upslope; and   identifying, within the search window of the first signal, an onset of the waveform pulse.   
     
     
         31 . The tool of  claim 5 , wherein
 the search window is defined by window locations;   the window locations comprise a start window location and an end window location;   the start window location corresponds to the second time value; and   the end window location corresponds to the first time value.   
     
     
         32 . The tool of  claim 1 , wherein the sharp upslope is identified based on a relatively large change within a portion of the first signal compared to a remainder of the first signal.