Patent
Hemodynamic monitor and method of hemodynamic monitoring
| العنوان: | Hemodynamic monitor and method of hemodynamic monitoring |
|---|---|
| Patent Number: | 10188,303 |
| تاريخ النشر: | January 29, 2019 |
| Appl. No: | 13/578334 |
| Application Filed: | February 10, 2011 |
| مستخلص: | An apparatus and method for determining stroke volume. The apparatus receives an arterial pressure waveform and is arranged to correct a part of the pressure waveform that relates to a heart beat for an influence of an ectopic heart beat, of atrial fibrillation on the pressure waveform or of changes in the pressure waveform's baseline. The apparatus also comprising means arranged to calculate the stroke volume from the corrected waveform. |
| Inventors: | Band, David Marston (Worplesdon, GB); O'Brien, Terence Kevin (Cambridge, GB); Mills, Eric (London, GB); Wolff, Christopher Bancroft (Cambridge, GB); Douglas, James Arthur (Kings Langley, GB) |
| Assignees: | LIDCO Group PLC (London, GB) |
| Claim: | 1. An apparatus for determining stroke volume comprising: an input for receiving an arterial pressure waveform; means arranged to define a start point within the arterial pressure waveform at a beginning of a systolic arterial pressure increase due to a ventricular contraction phase of a heart beat; means arranged to determine an end point of the heart beat for the purpose of calculating stroke volume by determining whether there is a part or point of the arterial pressure waveform that has substantially the same arterial pressure value as said starting point, responsive to said arterial pressure value at said starting point being regained, setting the end point to be the part or point of the arterial pressure waveform that has substantially the same arterial pressure value as said starting point, and responsive to said arterial pressure value at said starting point not being regained, extrapolating the end point of the heart beat to a point where the arterial pressure waveform has substantially the same arterial pressure value as said starting point to define the end point; means arranged to calculate a stroke volume from a part of the arterial pressure waveform or of the extrapolated arterial pressure waveform between the start point and the end point; and an output means and configured to output, via the output means, an indication of at least one of a current stroke volume, a current heart rate, a number of previous stroke volumes and a number of previous heart rates. |
| Claim: | 2. The apparatus according to claim 1 further comprising: means arranged to identify a baseline change in the arterial pressure waveform; and means arranged to correct the part of the arterial pressure waveform or of the extrapolated arterial pressure waveform between the start point and the end point to account for said baseline change; wherein the stroke volume is calculated from the corrected part of the arterial pressure waveform or of the extrapolated arterial pressure waveform. |
| Claim: | 3. The apparatus of claim 1 , the apparatus configured to correct part of the arterial pressure waveform or of the extrapolated arterial pressure waveform between the start point and the end point for an influence of an ectopic heart beat or of atrial fibrillation or of respiratory changes on the pressure waveform, wherein the stroke volume is calculated from the corrected part of the arterial pressure waveform or of the extrapolated arterial pressure waveform. |
| Claim: | 4. An apparatus according to claim 1 , further configured to identify a trend in the last half, third, quarter or fifth of a part of the arterial pressure waveform relating to one heart beat and extrapolating the arterial pressure waveform by continuing the identified trend until a value substantially corresponding to the value of the start point is reached. |
| Claim: | 5. An apparatus according to claim 4 , wherein identifying said trend comprises determining a gradient in the said part of the arterial pressure waveform and wherein continuing the trend comprises extending the arterial pressure waveform using the determined gradient. |
| Claim: | 6. An apparatus according to claim 1 , further configured to apply a non-linear correction to the arterial pressure waveform. |
| Claim: | 7. An apparatus according to claim 1 , further configured to calculate the stroke volume by determining the pulsatility of the part of the arterial pressure waveform relating to a heart beat between the start point and the end point. |
| Claim: | 8. An apparatus according to claim 7 , further configured to determine an absolute stroke volume by multiplying the pulsatility with a calibration factor specific to a patient. |
| Claim: | 9. An apparatus according to claim 1 , configured to determine cardiac output by multiplying stroke volume with a heart rate. |
| Claim: | 10. An apparatus according to claim 1 , configured to store the stroke volumes or cardiac outputs for a number of heart beats and to provide an indication should a fluctuation in the stroke volume or the cardiac output over time exceed a predetermined value. |
| Claim: | 11. An apparatus according to claim 1 , further configured to determine a heart rate based on the received arterial pressure waveform by performing autocorrelation on the arterial pressure waveform over a number of consecutive beats. |
| Claim: | 12. An apparatus for monitoring patient respiration comprising an apparatus according to claim 1 , the apparatus configured to determine a respiratory rate based on cyclic changes in the stroke volume or cardiac output. |
| Patent References Cited: | 3835839 September 1974 Brown 4834107 May 1989 Warner 5743267 April 1998 Nikolic 2001/0056242 December 2001 Palti 2005/0154422 July 2005 Band 2006/0167361 July 2006 Bennett et al. 2006/0235323 October 2006 Hatib 2008/0183232 July 2008 Voss 2009/0131805 May 2009 O'Brien et al. 2010/0076326 March 2010 Cohen 2010/0152592 June 2010 Hatib 2013/0006126 January 2013 Band et al. 1045718 May 2004 2533685 December 2012 S4731655 November 1972 S6111020 January 1986 H0532085 August 1993 WO 93/09427 May 1993 WO 97/00017 January 1997 WO 97/24982 July 1997 WO 00/64339 November 2000 WO 2008/144404 November 2008 2009/068233 June 2009 |
| Other References: | International Search Report corresponding to co-pending International Patent Application Serial No. PCT/GB2011/000176, European Patent Office, dated Apr. 20, 2011; (4 pages). cited by applicant International Written Opinion corresponding to co-pending International Patent Application Serial No. PCT/GB2011/000176, European Patent Office, dated Apr. 20, 2011; (7 pages). cited by applicant European Office Action corresponding to co-pending European Patent Application Serial No. 11705649.9, European Patent Office, dated Jul. 29, 2015; (4 pages). cited by applicant Rhodes et al., “Arterial Pulse Power Analysis: The LiDCO™plus System”, Functional Hemodynamic Monitoring Update in Intensive Care and Emergency Medicine, 42, pp. 183-192, 2005. cited by applicant Wolff et al., “A Simple Volume Related Model of Arterial Blood Pressure Generation”, Adv. Exp. Med. Biol., vol. 614, pp. 109-117, 2008. cited by applicant Liu et al., “Aortic Compliance in Human Hypertension”, Hypertension, 1989, 14: pp. 129-136. cited by applicant Lysander et al., “Non-Invasive Pulsatile Arterial Pressure from the Human Finger”, Experimental Physiology, 90:4, pp. 437-446, 2005. cited by applicant Jonas et al., “Real Time, Continuous Monitoring of Cardiac Output and Oxygen Delivery”, in International Journal of Intensive Care, vol. 9, No. 1, pp. 33-42, 2002. cited by applicant International Search Report for Application No. GB1002331.5, Intellectual Property Office UK, dated Jun. 30, 2010, 2 pages. cited by applicant international Examination Report for Application No. GB1002331.5, Intellectual Property Office UK, dated Jul. 1, 2010, 5 pages. cited by applicant Notice of Reasons for Rejection for Japanese Patent Application No. JP 2012-552460, dated Oct. 15, 2014, 2 pages. cited by applicant |
| Assistant Examiner: | Tran, Tho |
| Primary Examiner: | Cheng, Jacqueline |
| Attorney, Agent or Firm: | Nixon Peabody LLP |
| رقم الانضمام: | edspgr.10188303 |
| قاعدة البيانات: | USPTO Patent Grants |
| الوصف غير متاح. |