Cardiogram waveform correcting and displaying device and a method of correcting and displaying cardiogram waveforms

• US 8,103,335 B2
• Filed: 12/20/2005
• Issued: 01/24/2012
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Nihon Kohden Corporation
• Original Assignee: Nihon Kohden Corporation
• Inventors: Nagai, Ryuji, Nagata, Shinya
• Primary Examiner(s): Schaetzle, Kennedy
• Application Number:
  US11/722,320
• Publication Number:
  US 20080027339A1
• Time in Patent Office: 2,226 Days
• Field of Search: None
• US Class Current: 600/523
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor

Abstract

A cardiogram waveform correcting and displaying device is disclosed that is capable of facilitating visibility of cardiogram waveforms. A first filtering system 58-1 through nth filtering system 58-n are low-cut filters, each having a first cutoff frequency fc1 through an nth cutoff frequency fcn, respectively. Recognition module recognizes feature values of waveforms related to variation of the waveforms in accordance with any outputs of the first filtering system 58-1 through the nth filtering system 58-n. Judging module 62 selects which of the first through the nth filter is used based on the recognized feature values with the recognition module. A filter which restricts base-line variation is used when the base-line variation is large, and a filter having less influence to waveforms is used when the base-line variation is small. Display controller displays on a display portion output of the selected filter.

Claims

1. A cardiogram waveform display device for displaying cardiogram waveforms comprising:

a waveform data storage portion that stores waveform data which is converted to digital data from cardiogram waveform signals measured with a cardiograph;

a first to an n th filtering means, for carrying out low frequency cut-off processing of the waveform data stored in the storage portion, and for acquiring a first to an n th corrected waveform data, each of the filtering means having a different cut-off frequency;

selecting means, for recognizing an amount of variation of a base-line for each of a plurality of segments relative to at least any one of the waveform data and the first to the n th corrected waveform data, and for selecting any one of the first to the n th filters in accordance with the amount of variation of the base-line for each of the segments; and

display control means for displaying output of the filter selected for each of the segments by the selecting means.

2. A cardiogram waveform display device according to claim 1, wherein the display control means simultaneously displays an output of a filter having a lowest cut-off frequency out of the waveform data or the first to the n th corrected waveform data correspondently with an output of a filter selected by the selecting means.

3. A cardiogram waveform display device according to claim 1, wherein the selecting means recognizes an amount of variation of the base-line by calculating feature values of the waveform data or the corrected waveform data for each of the segments.

4. A cardiogram waveform display device according to claim 3, wherein the selecting means uses a waveform value for at least one of a P-wave, a Q-wave, an R-wave, a S-wave, a ST-segment and a T-wave as the feature values.

5. A cardiogram waveform display device according to claim 4, wherein the selecting means uses a waveform value of a point Pb or a waveform value of a point Qb as the feature values.

6. A cardiogram waveform display device according to claim 4, wherein for larger differences between the waveform value and a reference value, the selecting means selects filtering means having a higher cut-off frequency.

7. A cardiogram waveform display device according to claim 4, wherein the first cut-off frequency is a low cut-off frequency for performing functions of a cardiogram monitoring device as defined in the JIST 1304 standard.

8. A cardiogram waveform display device according to claim 3, wherein the cut-off frequency of the first to n th filters grows sequentially from the first filter, the second filter and up to the n th filter, and wherein the selecting means calculates an average of absolute values in difference between the first to the n th corrected waveform data for each of the plurality of segments as the feature value, and selects one of the filters in accordance with the averaged value in difference.

9. A cardiogram waveform display device according to claim 8, wherein the display control means displays either an output of a filter having a lowest cut-off frequency out of the waveform data or the first to the n th corrected waveform data correspondently with an output of a filter selected by the selecting means.

10. A cardiogram waveform display device according to claim 8, wherein the selecting means calculates average values, of a first to an n−

1 th for each of the plurality of segments, of absolute values in difference between the first to the n−

1 th corrected waveform data for each of the plurality of segments and selects a filter having a lowest cut-off frequency among values having equal or less than a predetermined reference value in the average values of the first to the n−

1 th.

11. A cardiogram waveform display device according to claim 10, wherein the selecting means selects the n th filter when there is no value equal to or less than the predetermined reference value in the average values of the first to the n−

1 th.

12. The cardiogram waveform display device according to claim 8, wherein the selecting means carries out selection of a filter using averaged difference values together with waveform values for at least one of the a P-wave, a Q-wave, an R-wave, a S-wave, a ST-segment and T-wave.

13. A cardiogram waveform display device according to claim 8, wherein the first to the fourth filters are provided, each having the first to the fourth cut-off frequency, respectively.

14. A cardiogram waveform display device according to claim 13, wherein the first cut-off frequency is a low cut frequency required by a cardiograph defined in JIST 1202, and wherein the second cut-off frequency is a low cut frequency required by a cardiogram monitoring device defined in JIST 1304.

15. A cardiogram waveform display device according to claim 14, wherein the display control means controls so that the first corrected waveform data processed with the first cut-off frequency, the second corrected waveform data processed with the second cut-off frequency, the third corrected waveform data processed with the third cut-off frequency and the fourth corrected waveform data processed with the fourth cut-off frequency are displayed such that they are discriminable relative to one another.

16. A cardiogram waveform display device according to claim 13, further comprising a fifth to a seventh filters, each having a fifth to a seventh cut-off frequency, respectively.

17. A cardiogram waveform display device according to claim 3, further comprising feature value calculation means for supplemental use of diagnosing clinical conditions which calculates feature values for supplemental use of diagnosing clinical conditions for one of waveform data and corrected waveform data in each of the plurality of segments, wherein the display control means controls to display the feature values for supplemental use of diagnosing clinical conditions.

18. A cardiogram waveform display device according to claim 17, wherein the display control means controls to display feature values for supplemental use of diagnosing clinical conditions in accordance with corrected waveform data processed by the filter selected with the selecting means, and further controls to carry out display for recognizing whether the feature values for supplemental use are based on corrected waveform data excessively restricting its base-line over a range defined in a corresponding JIS standard.

19. A cardiogram waveform display device according to claim 1, wherein the first filtering means has a first cut-off frequency and the second filtering means has a higher cut-off frequency than the first cut-off frequency, and wherein the selecting means selects one of the first filtering means and the second filtering means.

20. A cardiogram waveform display device according to claim 1, wherein the display control means controls to display a display object so that the display object belonging to, either any one of the first corrected waveform data through the n th corrected waveform data or any group of the first corrected waveform data through the n th corrected waveform data being grouped, is identifiably displayed in a manner corresponding to the displayed waveform.

21. A cardiogram waveform display device according to claim 20, wherein the display control means controls to display a bar at a vicinity of the display waveform for each segment thereof, for recognizing whether the displayed waveform is corrected waveform data excessively restricting its base-line over a range defined in a corresponding JIS standard.

22. A cardiogram waveform display device according to claim 1, wherein each of the plurality of segments represents one cardiac beat.

23. A cardiogram waveform display device according to claim 22, wherein the display control means adjusts corrected waveform data, so that the corrected waveform data to be displayed sequentially in accordance with tail waveform data behind a tail of a T-wave of preceding corrected waveform data, and corresponding tail waveform data of subsequent corrected waveform data in precedent cardiogram segments, when continuity of the corrected waveform data to be displayed is lost because precedent corrected waveform data selected for precedent cardiogram segments and subsequent corrected waveform data selected for subsequent cardiogram segments to the precedent waveform data are different from each other.

24. A cardiogram waveform processing program according to claim 1, wherein the display control means simultaneously displays an output of a filter having a lowest cut-off frequency out of the waveform data or the first to the n th corrected waveform data correspondently with an output of a filter selected by the selecting means.

25. A cardiogram waveform processing program according to claim 1, wherein the selecting means recognizes an amount of variation of the base-line by calculating feature values of the waveform data or the corrected waveform data for each of the segments.

26. A cardiogram waveform processing program according to claim 25, wherein the selecting means uses a waveform value for at least one of a P-wave, a Q-wave, an R-wave, a S-wave, a ST-segment and a T-wave as the feature values.

27. A cardiogram waveform processing program according to claim 26, wherein the selecting means uses a waveform value of a point Pb or a waveform value of a point Qb as the feature values.

28. A cardiogram waveform processing program according to claim 26, wherein for larger differences between the waveform value and a reference value, the selecting means selects filtering means having a higher cut-off frequency.

29. A cardiogram waveform processing program according to claim 26, wherein the first cut-off frequency is a low cut-off frequency for performing functions of a cardiogram monitoring device defined in JIST 1304.

30. A cardiogram waveform processing program according to claim 25, wherein the cut-off frequency of the first to n th filters grows sequentially from the first filter, the second filter and up to the n th filter, and wherein the selecting means calculates an average of absolute values in difference between the first to the n th corrected waveform data for each of the plurality of segments as the feature value, and selects one of the filters in accordance with the averaged value in difference.

31. A cardiogram waveform processing program according to claim 30, wherein the display control means displays either an output of a filter having a lowest cut-off frequency out of the waveform data or the first to the n th corrected waveform data correspondently with an output of a filter selected by the selecting means in a simultaneous manner.

32. A cardiogram waveform processing program according to claim 31, wherein the selecting means carries out selection of a filter using the averaged difference values together with waveform values for at least one of a P-wave, a Q-wave, an R-wave, a S-wave, a ST-segment and a T-wave as a criterion of the selection.

33. A cardiogram waveform processing program according to claim 31, wherein the first to a fourth filter is provided each having a first to a fourth cut-off frequency, respectively.

34. A cardiogram waveform processing program according to claim 33, wherein the first cut-off frequency is a low cut frequency required by a cardiograph defined in JIST 1202, and wherein the second cut-off frequency is a low cut frequency required by a cardiogram monitoring device defined in JIST 1304.

35. A cardiogram waveform processing program according to claim 34, wherein the display control means controls so that the first corrected waveform data processed with the first cut-off frequency, the second corrected waveform data processed with the second cut-off frequency, the third corrected waveform data processed with the third cut-off frequency and the fourth corrected waveform data processed with the fourth cut-off frequency are displayed so that they are discriminable relative to one another.

36. A cardiogram waveform processing program according to claim 33, further comprising a fifth to a seventh filters each having a fifth to a seventh cut-off frequency, respectively.

37. A cardiogram waveform processing program according to claim 30, wherein the selecting means calculates average values of a first to an n−

1 th for each of the plurality of segments of absolute values in difference between the first to the n−

1 th corrected waveform data for each of the plurality of segments, and selects a filter having a lowest cut-off frequency among values having equal or less than a predetermined reference value in the average values of the first to the n−

1 th.

38. A cardiogram waveform processing program according to claim 37, wherein the selecting means selects the n th filter when there is no value equal to or less than the predetermined reference value in the average values of the first to the n−

1 th.

39. A cardiogram waveform processing program according to claim 25, further comprising feature value calculation means for supplemental use of diagnosing clinical conditions which calculates feature values for supplemental use of diagnosing clinical conditions for one of waveform data and corrected waveform data in each of the plurality of segments, wherein the display control means controls to display the feature values for supplemental use of diagnosing clinical conditions.

40. A cardiogram waveform processing program according to claim 39, wherein the display control means controls to display feature values for supplemental use of diagnosing clinical conditions in accordance with corrected waveform data processed by the filter selected with the selecting means, and further controls to carry out display for recognizing whether the feature values for supplemental use are based on corrected waveform data excessively restricting its base-line over a range defined in a corresponding JIS standard.

41. A cardiogram waveform processing program according to claim 1, wherein the first filtering means has a first cut-off frequency and the second filtering means has a higher cut-off frequency than the first cut-off frequency, and wherein the selecting means selects one of the first filtering means and the second filtering means.

42. A cardiogram waveform processing program according to claim 1, wherein the display control means controls to display a display object so that the display object belonging to, either:

any one of the first corrected waveform data through the n th corrected waveform data, or any group of the first corrected waveform data through the n th corrected waveform data being grouped, is identifiably displayed corresponding to the displayed waveform.

43. A cardiogram waveform processing program according to claim 42, wherein the display control means controls to display a bar at a vicinity of the display waveform for each segment thereof, for recognizing whether or not the displayed waveform is corrected waveform data excessively restricting its base-line over a range defined in a corresponding JIS standard.

44. A cardiogram waveform processing program according to claim 1, wherein each of the plurality of segments represents one cardiac beat.

45. A cardiogram waveform processing program according to claim 44, wherein the display control means adjusts corrected waveform data so that the waveform data to be displayed sequentially, in accordance with tail waveform data behind a tail of T-wave preceding corrected waveform data, and corresponding tail waveform data in cardiogram segments preceding subsequent corrected waveform data, when continuity of the corrected waveform data to be displayed is lost because precedent waveform data selected for precedent cardiogram segments and subsequent corrected waveform data selected for subsequent cardiac segments to the precedent waveform data are different from each other.

46. A cardiogram waveform processing program executable to cause a computer to perform as a cardiogram waveform display device, the program including instructions stored on a non-transitory information storage media, the instructions controlling:

a first to an n th filtering means, for carrying out low frequency cut-off processing of waveform data which is converted to digital data from cardiogram waveform signals measured with a cardiograph;

selecting means for recognizing an amount of variation of a base-line for each of a plurality of segments relative to at least any one of the waveform data and the first to the n th corrected waveform data, and for selecting any one of the first to the n th filters in accordance with the amount of variation of the base-line for each of the segments; and

display control means for displaying output of the filter selected for each of the segments by the selecting means.

47. A cardiogram waveform display device for selecting an appropriate filter for each one of a plurality of cardiac segments upon receipt of cardiogram waveform signals that were measured with a cardiograph, and for displaying output waveforms of the filter, wherein the cardiogram waveform display device either displays:

which one of a plurality of filters is selected for a corresponding to an output waveform for each one of a plurality of cardiac beats, or

for filters grouped in a plurality of groups, which one of filters belonging to which group is selected, together with an output waveform of the selected filter for each cardiac beat.

48. A method of displaying cardiogram waveforms using a computer comprising the steps of:

generating waveform data by converting cardiogram waveform signals measured with a cardiograph to digital data;

carrying out low frequency cut-off processing at a first to an n th cut-off frequencies to the waveform data and performing a first to an n th filtering process to acquire a first to an n th corrected waveform data;

recognizing feature values representing variations of a base-line for each of a plurality of predetermined segments relative to any one of the waveform data and the first to the n th corrected waveform data; and

selecting one of the first to the n th filters in accordance with the feature values and displaying output of the filter selected by the selecting means for each of the predetermined segments.