| 1. |
- Grigonyte, Egle, et al.
(författare)
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Relative peripheral blood volume changes in response to ventricular premature beats during dialysis
- 2013
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Ingår i: [Host publication title missing]. - 2325-8861. ; 40, s. 209-212
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Konferensbidrag (refereegranskat)abstract
- The goal of this study is to determine whether peripheral blood volume fluctuations triggered by ventricular premature beats (VPBs) are significantly related to hypotensive symptoms during dialysis treatment. Patients treated with hemodialysis often suffer from cardiovascular disorders and uremic neuropathy, increasing the propensity to homeostatic imbalance that, in turn, may result in intradialytic hypotension, cramps, nausea, dizziness, headache and other complications. VPBs, being abundant in hemodialysis patients, can be viewed as an internal disturbance leading to imbalance through acute blood pressure drop and prolonged tissue deoxygenation. The present study investigates and quantifies VPB-induced relative peripheral blood volume changes, measured from the fingertip photoplethysmographic (PPG) waveform, and their significance for characterization of physiological recovery of a disturbed circulatory state. The mean decrease in PPG amplitude, corresponding to an initial post-ectopic drop in blood volume delivered to the periphery, was 4 ± 3% in asymptomatic treatments, whereas 17 ± 3% in symptomatic dialysis treatments. This result indicates that significant differences exist between the two groups of treatment, providing a potential for development of intradialytic risk predictors.
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| 2. |
- Grigonytė, Eglė, et al.
(författare)
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Relative peripheral blood volume changes induced by premature ectopic beats and their role in hemodialysis
- 2017
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Ingår i: Biomedical Signal Processing and Control. - : Elsevier BV. - 1746-8094. ; 31, s. 524-528
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Tidskriftsartikel (refereegranskat)abstract
- Hemodialysis patients often suffer from cardiovascular disorders and uremic neuropathy, increasing the propensity to homeostatic imbalance that, in turn, may result in intradialytic complications like cramp, nausea, and, worse, hypotension. Ectopic beats, being abundant in such patients, may lead to imbalance through repeated, sudden drops in blood pressure. By exploring the properties of postectopic peripheral circulation recovery, treatment sessions prone to intradialytic complications may be better identified. This paper introduces a novel method for quantifying changes in peripheral blood volume due to ventricular or supraventricular premature beats (VPBs or SVPBs). Using the fingertip photoplethysmographic pulse waveform, VPB and SVPB-induced changes in relative peripheral blood volume are quantified by the postectopic pulse amplitude. Two parameters are proposed for characterizing (i) the initial drop in peripheral blood volume following an ectopic beat, and (ii) the degree of postectopic peripheral circulation recovery. A small set of data from 16 hemodialysis sessions in 9 hypotension-prone patients are used to illustrate the method. In asymptomatic sessions, the first parameter was found to be 8 ± 13% (mean ± std), whereas, in symptomatic sessions, it increased to 32 ± 13%, suggesting that postectopic pulse amplitude recovery is related to intradialytic complications; similar results were obtained for the second parameter. Postectopic pulse amplitude recovery may also be of interest in other applications where relative changes in peripheral blood volume play a role.
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| 3. |
- Holmer, Mattias, et al.
(författare)
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Determining Heart Activity Present in the Pressure Sensors of a Dialysis Machine
- 2013
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Ingår i: Computing in Cardiology. - 2325-8861. ; , s. 217-220
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Konferensbidrag (refereegranskat)abstract
- Determination of heart status during dialysis can im- prove patient monitoring. Pressure sensors in the dialysis machine measures the heart pulses that propagates in the body and enter the extracorporeal blood circuit. A peri- staltic blood pump, located in the same circuit, introduces strong periodic pressure pulses that interfere with the much weaker cardiac component. These signal characteristics make the extraction of the heart activity challenging. In the present study, we explore the possibility to extract and analyze the cardiac component using simulated data. The accuracy of the timing of each heartbeat is analyzed. Ad- ditionally, the heart component is extracted from patient pressure recordings, and compared to the heart rate com- puted from a photoplethysmogram. The results show that heart timings can be accurately determined using the pres- sure sensors of a dialysis machine.
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| 4. |
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| 5. |
- Holmer, Mattias, et al.
(författare)
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Extracting a Cardiac Signal From the Extracorporeal Pressure Sensors of a Hemodialysis Machine
- 2015
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Ingår i: IEEE Transactions on Biomedical Engineering. - 1558-2531. ; 62:5, s. 1305-1315
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Tidskriftsartikel (refereegranskat)abstract
- Although patients undergoing hemodialysis treatment often suffer from cardiovascular disease, monitoring of cardiac rhythm is not performed on a routine basis. Without requiring any extra sensor, this study proposes a method for extracting a cardiac signal from the built-in extracorporeal venous pressure sensor of the hemodialysis machine. The extraction is challenged by the fact that the cardiac component is much weaker than the pressure component caused by the peristaltic blood pump. To further complicate the extraction problem, the cardiac component is difficult to separate when the pump and heart rates coincide. The proposed method estimates a cardiac signal by subtracting an iteratively refined blood pump model signal from the signal measured at the extracorporeal venous pressure sensor. The method was developed based on simulated pressure signals, and evaluated on clinical pressure signals acquired during hemodialysis treatment. The heart rate estimated from the clinical pressure signal was compared to that derived from a photoplethysmographic reference signal, resulting in a difference of 0.07 +/- 0.84 beats/min. The accuracy of the heartbeat occurrence times was studied for different strengths of the cardiac component, using both clinical and simulated signals. The results suggest that the accuracy is sufficient for analysis of heart rate and certain arrhythmias.
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| 6. |
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| 7. |
- Holmer, Mattias, et al.
(författare)
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On-line Heart Rate Monitoring Using the Extra-corporeal Pressure Sensors of a Dialysis Machine
- 2012
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Ingår i: Biomedical engineering – 2012 : proceedings of international conference. - 2029-3380.
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Konferensbidrag (refereegranskat)abstract
- Heart rate can be extracted from the extracorporeal venous pressure signal of a dialysis machine. The results are of comparable accuracy and reliability to the ones obtained by the PPG reference signal from a pulse oximeter. Difficulties that occur during heart rate estimation were determined, and some can be overcome by a slight adjustment of blood flow rate. The described techniques, after being implemented into the dialysis machines, would help to improve current hemodialysis safety throughout the treatment by on-line monitoring of the cardiac activity.
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