A new electrocardiogram(ECG) data compression method is presented.It employs a repeated coding.In this method beat templates are extracted from original signals according to the features of ECG.The data are divided in...A new electrocardiogram(ECG) data compression method is presented.It employs a repeated coding.In this method beat templates are extracted from original signals according to the features of ECG.The data are divided into three parts:beat template,residual and position parameter.The three separate parts are first encoded with LADT,and then use the lossless entropy encoding to maintain a low level of reconstructed waveform distortion.The entropy encoding based on Huffman encoding is employed here as an example.Selections from the MIT BIH arrhythmia database,show that there is substantial improvement in compression ratio (CR) over other single and simple compression methods for comparable percent root mean square difference(PRD).展开更多
Background Fall injuries are common among the elderly. The aim of this study was to investigate whether blood-pressure patterns, as measured by 24-h ambulatory blood pressure monitoring (ABPM), or intensification of...Background Fall injuries are common among the elderly. The aim of this study was to investigate whether blood-pressure patterns, as measured by 24-h ambulatory blood pressure monitoring (ABPM), or intensification of antihypertensive therapy following the 24-h ABPM, may be associated with fall injuries in hypertensive elderly patients. Methods In a retrospective study, community-based elderly patients (age ≥ 70 years) who were referred to 24-h ABPM were evaluated for fall injuries within one-year post-ABPM. We compared the clinical characteristics, 24-h ABPM patterns and the intensification of hypertensive therapy following 24-h ABPM, between patients with and without a fall injury. Results Overall 1032 hypertensive elderly patients were evaluated. Fifty-five (5.3%) had a fall injury episode in the year following ABPM. Patients with a fall injury were significantly older, and with higher rates of previous falls. Lower 24-h diastolic blood-pressure (67.3 ± 7.6 vs. 70.7 ± 8.8 mmHg; P 〈 0.005) and increased pulse-pressure (74.7 ± 14.3 vs. 68.3 ± 13.7 mmHg; P 〈 0.005), were found in the patients with a fall injury, compared to those without a fall injury. After adjustment for age, gender, diabetes mellitus and previous falls, lower diastolic blood-pressure and increased pulse-pressure were independent predictors of fall injury. Intensification of antihypertensive treatment following the 24-h ABPM was not associated with an increased rate of fall injury. Conclusions Low diastolic blood-pressure and increased pulse-pressure in 24-h ABPM were associated with an increased risk of fall injury in elderly hypertensive patients. Intensification of antihypertensive treatment following 24-h ABPM was not associated with an increased risk of fall injury.展开更多
Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case su...Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups. Results The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ~ 5.6 per-year in group I, 10.8 ~ 3.9 per-year in group II, and 9.8 -4- 4.2 per-year in group HI. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1-7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity. Conclusions This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.展开更多
Objective We investigated the efficacy and safety of 1064 nm Nd: YAG laser, intense pulsed light (IPL), and lauromacrogol injection in the treatment of hemangioma, in order to evaluate the value of color Doppler u...Objective We investigated the efficacy and safety of 1064 nm Nd: YAG laser, intense pulsed light (IPL), and lauromacrogol injection in the treatment of hemangioma, in order to evaluate the value of color Doppler ultrasound guidance in choosing the optimal treatment modality. Methods Infantile patients who were clinical diagnosed as hemangiomas were randomly divided into group A, who had color Doppler ultrasound examinations before the treatment, and group B who had the treatment without ultrasound evaluation. Patients in the group A were assigned into subgroups according to the depth of lesion by sonography: group A-1 for those who had a lesion depth 〈1.2 mm, and took intense pulsed light therapy; group A-2 for those who had a lesion depth ≥1.2mm and 〈 3 mm, and took long pulse 1064 nm Nd:YAG laser therapy; group A-3 for those who had a lesion depth ≥3mm and 〈5 mm, and were treated by IPL combined with long pulse 1064 nm Nd:YAG laser treatment; Group A-4 for those who had a lesion depth ≥5 mm, and took lauromacrogol injection therapy. Patients in the group B took long pulse 1064 nm Nd:YAG laser treatment without preoperative ultrasound evaluation. The efficacy and adverse reactions of the treatments between the groups were evaluated and compared statistically. Results Totally 113 patients with 128 skin lesions were enrolled in this study, 85 in the group A (mean age 6.8±7.9 months) and 28 in the group B (mean age 6.9±9.9 months). The mean depth of hemangioma was 3.3±1.1 mm in the group A, ranging from 0.5-7.8 mm, with 0.8±0.4 mm, 2.2±0.4 mm, 4.2±0.6 mm and 6.2±0.7 mm in group A1, A2, A3 and A4, respectively. The cure rates and effective rates in the group A were significantly higher than those in the group B (cure rates: 64.5% vs 56.3%, U=3.378, P=0.045; effective rates: 89.5% vs 78.1%, U=4.163, P=0.041). The adverse effect rates of the group A (vesicle 20.0%, pigmentation 46.9%, scarring 17.7%) were lower than those of the group B (vesicle 21.9%, pigmentation 60.4%, scarring 25.0%). Incidences of pigmentation and scarring were statistically significantly different (U=3.884, P=0.034, and U=4.016, P=0.032 respectively) between the two groups. Conclusion With the guidance of color Doppler ultrasound, the efficacy and safety of long pulse 1064 nmNd:YAG laser, intense pulsed light, and lauromacrogol injection in the treatment of infantile hemangioma have better outcomes compared to laser treatment alone without preoperative ultrasound examination.展开更多
Objective To assess the prevalence of the bleeding complications in pacemaker implanted patients receiving different antiplatelet regimens, and the influence of each regimen on hospital stays after device implantation...Objective To assess the prevalence of the bleeding complications in pacemaker implanted patients receiving different antiplatelet regimens, and the influence of each regimen on hospital stays after device implantation. Methods We prospectively enrolled 364 patients receiving the cardiac rhythm device implantations in Fuwai Hospital from July 2012 to December 2013. Bleeding complications including pocket hematoma, hemothorax, cardiac tamponade and blood transfusion requirement were measured as endpoints. Post operation hospital stay was also included in the endpoints. Results Bleeding complications were detected in 15 patients (14 with hematoma, one with hemothorax) out of all 364 patients (4.12%). Dual antiplatelet therapy (DAT) significantly increased hematoma (19.3%) compared with aspi- fin treatment (ASA) (3.2%, P = 0.001) and no antiplatelet therapy (1.9%, P 〈 0.001). There was no significant difference in incidence of pocket hematoma between the ASA group and the control group (P = 0.45). The post procedure hospital stay was longer in DAT group (5.45 ± 2.01 days) compared to those in the ASA group (3.65 ± 1.37 days, P 〈 0.05) or control group (3.99 ± 2.27 days, P 〈 0.05). Pocket hema- toma was considered an independent predictor of hospital stay prolongation (OR: 5.26; 95% CI: 1.56-16.64; P = 0.007). Conclusions Among the Chinese patients undergoing device implantation in this study, the use of dual antiplatelet agents significantly increased the risk of pocket hematoma complications and led to a longer hospital stay. Use of aspirin alone did not increase the risk.展开更多
Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into ...Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into two groups. Anticoagulation group( Group A) consisted of 71 patients who were given heparin intravenously with target aPTT 50 - 70 seconds. Non-anticoagulation group( Group B) consisted of 82 patients without intravenous heparin during balloon pumping. Hematological parameters including platelet count, D-dimer, Plasminogen activator inhibitor-1 (PAI-1) and fibrinogen degradation products(FDP) were checked respectively at the point of baseline, 24 hours, 48 hours and 24 hours post IABP counterpulsation. Clot deposits on balloon surface, vascular complications from IABP including bleeding and limb ischemia were recorded.Results: Platelet count and PAI-1 level decreased at 24 hours and 48 hours in both groups ( P < 0.05) . D-dimer and FDP level increased at 24 hours and 48 hours in both groups( P < 0.05), but returned to the baseline level 24 hours post IABP removal( P > 0.05) . Three patients in Group A and 2 patients in Group B developed minor limb ischemia( P > 0.05). No major limb ischemia in either group. Two patients in Group A suffered major bleeding and required blood transfusion or surgical intervention, whereas no patient had major bleeding in Group B. Eight patients had minor bleeding in Group A, but only 2 patients in Group B ( P <0.05). No clot deposit developed on IABP surface in either group. Conclusion: IABP is safe without routine anticoagulation therapy. Selecting appropriate artery approach and early detection intervention are key methods for preventing complications.展开更多
Photoplethysmogram(PPG)is a noninvasive method for detecting human cardiovascular pulse wave using optical technology.The PPG containing a lot of physiological information is from the MIMIC database.This paper propose...Photoplethysmogram(PPG)is a noninvasive method for detecting human cardiovascular pulse wave using optical technology.The PPG containing a lot of physiological information is from the MIMIC database.This paper proposes a combinatorial method of ensemble empirical mode decomposition(EEMD),cepstrum,fast Fourier transform(FFT)and zero-crossing detection to improve the robustness of the estimation of pulse rate(PR),heart rate(HR)and respiratory rate(RR)from the PPG.First,the PPG signal was decomposed into finite intrinsic mode functions(IMF)by EEMD.Because of its adaptive filtering property,the different signals were reconstructed using different IMFs when estimating different physiological parameters.Second,the PR was obtained by zero-crossing detection after rejecting low frequency IMFs containing artifacts.Third,IMFs with frequency between 1.00 Hz to 1.67 Hz(60 beats/min to 100 beats/min)were selected for estimating HR.Then,the frequency band that reflects the heart activity was analyzed by the cepstrum method.Finally,the respiratory signal can be extracted from PPG signal by IMFs with frequency between 0.05 Hz to 0.75 Hz(3 breahts/min to 45 breaths/min).Then the spectrum of signal was obtained by FFT analysis and the RR was estimated by detecting the maximum frequency peak.The algorithm has been tested on MIMIC database obtained from 53 adults.The experiment results show that the physiological parameters extracted by this integrated signal processing method are consistent with the real physiological parameters.And the computation load of this method is small and the precision is high(not larger than 1.17%in error).展开更多
Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-inv...Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.展开更多
AIM: To investigate the effects and mechanisms of Verapamil on cultured human colonic tumor (HCT) cells.METHODS: HCT cells were treated with different concentrations of Verapamil, and their proliferation was examined ...AIM: To investigate the effects and mechanisms of Verapamil on cultured human colonic tumor (HCT) cells.METHODS: HCT cells were treated with different concentrations of Verapamil, and their proliferation was examined by MTT assay. The areas of sub-diploid peak were measured by flow cytometry, and the DNA ladder was found by agarose gel electrophoresis. The characteristic changes in morphology were observed under light microscopy. The cell nuclei (propidium iodide labeled, PI-labeled) and cellular distribution and concentration of calcium (Fluo-3-labeled) were studied by using laser confocal scanning microscope.RESULTS: The proliferation of HCT cells was inhibited by different concentrations of Verapamil. With the increase in concentration of Verapamil, the percent of G0-G1 phase cells in HCT cells increased and that of S phase cells decreased. After treating with different concentrations of Verapamil, flow cytometry showed that HCT cells were enlarged in areas of sub-diploid in a dose-dependent manner. Gel electrophoresis results displayed a typical DNA ladder. On staining with Wrights-Giemsa, the typical cellular apoptosis morphologic changes were also observed. PI-labeled cell nuclei were found markedly changed. In addition, we inspected that the 100 μmol/L Verapamil could increase the intracellular calcium ion concentration [Ca2+]i in HCT cells.CONCLUSION: Verapamil can inhibit proliferation of HCT cells via inducing cell apoptosis.展开更多
A kind of structure and a design method using transmission voltage-switch theory for pulse-triggered flip-flops were proposed,which are suitable for all kinds of pulse-triggered flip-flops and no extra techniques are ...A kind of structure and a design method using transmission voltage-switch theory for pulse-triggered flip-flops were proposed,which are suitable for all kinds of pulse-triggered flip-flops and no extra techniques are needed to eliminate the switching activities of internal nodes.Based on the proposed structure and design technique,two pulsed flip-flops were implemented and simulated.The proposed pulsed flip-flops have simple circuit structures.HSPICE simulation shows that the proposed pulsed D flip-flop outperforms the conventional pulsed D flip-flop by 17.2% in delay and 30.1% in power-delay-product(PDP) and the proposed pulsed JK flip-flop has low power and small PDP compared with pulsed D pulsed flip-flops,confirming that the proposed structure and design technique are simple and practical.展开更多
Objective To evaluate left univentricular (LUV) pacing for cardiac resynchronization therapy (CRT) using a rate-adaptive atrioven- tricular delay (RAAVD) algorithm to track physiological atrioventricular delay ...Objective To evaluate left univentricular (LUV) pacing for cardiac resynchronization therapy (CRT) using a rate-adaptive atrioven- tricular delay (RAAVD) algorithm to track physiological atrioventricular delay (AVD). Methods A total of 72 patients with congestive heart failure (CHF) were randomized to RAAVD LUV pacing versus standard biventricular (BiV) pacing in a 1 : 1 ratio. Echocardiography was used to optimize AVD for both groups. The effects of sequential BiV pacing and LUV pacing with optimized A-V (right atrio-LV) delay using an RAAVD algorithm were compared. The standard deviation (SD) of the S/R ratio in lead VI at five heart rate (HR) segments (Rs/R-SD5), defined as the "tracking index," was used to evaluate the accuracy of the RAAVD algorithm for tracking physiological AVD. Results TheQRS complex duration (132 ± 9.8 vs. 138± 10ms, P 〈 0.05), the time required for optimization (21 ±5 vs. 50±8min, P〈 0.001), the mitral regurgitant area (1.9 ± 1.1 vs. 2.5 ± 1.3 em2, P 〈 0.05), the interventricular mechanical delay time (60.7 ± 13.3 ms vs. 68.3 ± 14.2 ms, P 〈 0.05), and the average annual cost (13,200 ± 1000 vs. 21,600 ± 2000 RMB, P 〈 0.001) in the RAAVD LUV pacing group were significantly less than those in the standard BiV pacing group. The aortic valve velocity-time integral in the RAAVD LUV pacing group was greater than that in the standard BiV pacing group (22.7 ± 2.2 vs. 21.4 ± 2.1 cm, P 〈 0.05). The Rs/R-SD5 was 4.08 ± 1.91 in the RAAVD LUV pacing group, and was significantly negatively correlated with improved left ventricular ejection fraction (LVEF) (ALVEF, Pearson's r = -0.427, P = 0.009), and positively correlated with New York Heart Association class (Spearman's r - 0.348, P 0.037). Conclusions RAAVD LUV pacing is as effective as standard BiV pacing, can be more physiological than standard BiV pacing, and can de- crease the average annual cost of CRT.展开更多
文摘A new electrocardiogram(ECG) data compression method is presented.It employs a repeated coding.In this method beat templates are extracted from original signals according to the features of ECG.The data are divided into three parts:beat template,residual and position parameter.The three separate parts are first encoded with LADT,and then use the lossless entropy encoding to maintain a low level of reconstructed waveform distortion.The entropy encoding based on Huffman encoding is employed here as an example.Selections from the MIT BIH arrhythmia database,show that there is substantial improvement in compression ratio (CR) over other single and simple compression methods for comparable percent root mean square difference(PRD).
文摘Background Fall injuries are common among the elderly. The aim of this study was to investigate whether blood-pressure patterns, as measured by 24-h ambulatory blood pressure monitoring (ABPM), or intensification of antihypertensive therapy following the 24-h ABPM, may be associated with fall injuries in hypertensive elderly patients. Methods In a retrospective study, community-based elderly patients (age ≥ 70 years) who were referred to 24-h ABPM were evaluated for fall injuries within one-year post-ABPM. We compared the clinical characteristics, 24-h ABPM patterns and the intensification of hypertensive therapy following 24-h ABPM, between patients with and without a fall injury. Results Overall 1032 hypertensive elderly patients were evaluated. Fifty-five (5.3%) had a fall injury episode in the year following ABPM. Patients with a fall injury were significantly older, and with higher rates of previous falls. Lower 24-h diastolic blood-pressure (67.3 ± 7.6 vs. 70.7 ± 8.8 mmHg; P 〈 0.005) and increased pulse-pressure (74.7 ± 14.3 vs. 68.3 ± 13.7 mmHg; P 〈 0.005), were found in the patients with a fall injury, compared to those without a fall injury. After adjustment for age, gender, diabetes mellitus and previous falls, lower diastolic blood-pressure and increased pulse-pressure were independent predictors of fall injury. Intensification of antihypertensive treatment following the 24-h ABPM was not associated with an increased rate of fall injury. Conclusions Low diastolic blood-pressure and increased pulse-pressure in 24-h ABPM were associated with an increased risk of fall injury in elderly hypertensive patients. Intensification of antihypertensive treatment following 24-h ABPM was not associated with an increased risk of fall injury.
文摘Objective To describe the clinical characteristics of idiopathic ventricular fibrillation (IVF) with fragmented QRS complex (f-QRS) and J wave in resting electrocardiogram. Methods We reviewed data from 21 case subjects in our hospital who were resuscitated after cardiac arrest due to IVF and assessed the prevalence of f-QRS and J wave in resting electrocardiogram (ECG). All the case subjects were classified among three groups based on the electrocardiographic morphology: group I, both f-QRS and J wave were observed (n = 6), group II, only J wave was observed (n = 9), group III, neither f-QRS nor J wave was observed (n = 6). Population characteristics, history of syncope or sudden cardiac arrest, incidence of ventricular fibrillation (VF), and circumstance of VF were evaluated among the three groups. Results The incidence of index events (syncope, survived cardiac arrest and VF episodes recorded in implantable cardioverter defibrillator (ICD) or pacemakers) was 13.4 ~ 5.6 per-year in group I, 10.8 ~ 3.9 per-year in group II, and 9.8 -4- 4.2 per-year in group HI. There were significant differences in incidences among the three groups, the most frequent index events were observed in group I. The hazard ratio for incidence was 3.2 (95%CI, 1.1-7.9; P = 0.01). The history and circumstance of the index events were different among the groups. In group I, all the index events occurred during sleep in early morning. In group II, four subjects suffered VF during strenuous physical activities or agitation state, two during sleep in early morning, three in usual activity. In group III, one subject suffered VF during sleep in early morning, one in agitation state, four in usual activity. Conclusions This study suggests that the IVF patients with the combined appearance of f-QRS and J wave in the resting ECG suffer an increased risk of VF, this subgroup of IVF patients has a unique clinical feature.
基金Supported by grants of the National Natural Science of China(No.81000700No.81573072)
文摘Objective We investigated the efficacy and safety of 1064 nm Nd: YAG laser, intense pulsed light (IPL), and lauromacrogol injection in the treatment of hemangioma, in order to evaluate the value of color Doppler ultrasound guidance in choosing the optimal treatment modality. Methods Infantile patients who were clinical diagnosed as hemangiomas were randomly divided into group A, who had color Doppler ultrasound examinations before the treatment, and group B who had the treatment without ultrasound evaluation. Patients in the group A were assigned into subgroups according to the depth of lesion by sonography: group A-1 for those who had a lesion depth 〈1.2 mm, and took intense pulsed light therapy; group A-2 for those who had a lesion depth ≥1.2mm and 〈 3 mm, and took long pulse 1064 nm Nd:YAG laser therapy; group A-3 for those who had a lesion depth ≥3mm and 〈5 mm, and were treated by IPL combined with long pulse 1064 nm Nd:YAG laser treatment; Group A-4 for those who had a lesion depth ≥5 mm, and took lauromacrogol injection therapy. Patients in the group B took long pulse 1064 nm Nd:YAG laser treatment without preoperative ultrasound evaluation. The efficacy and adverse reactions of the treatments between the groups were evaluated and compared statistically. Results Totally 113 patients with 128 skin lesions were enrolled in this study, 85 in the group A (mean age 6.8±7.9 months) and 28 in the group B (mean age 6.9±9.9 months). The mean depth of hemangioma was 3.3±1.1 mm in the group A, ranging from 0.5-7.8 mm, with 0.8±0.4 mm, 2.2±0.4 mm, 4.2±0.6 mm and 6.2±0.7 mm in group A1, A2, A3 and A4, respectively. The cure rates and effective rates in the group A were significantly higher than those in the group B (cure rates: 64.5% vs 56.3%, U=3.378, P=0.045; effective rates: 89.5% vs 78.1%, U=4.163, P=0.041). The adverse effect rates of the group A (vesicle 20.0%, pigmentation 46.9%, scarring 17.7%) were lower than those of the group B (vesicle 21.9%, pigmentation 60.4%, scarring 25.0%). Incidences of pigmentation and scarring were statistically significantly different (U=3.884, P=0.034, and U=4.016, P=0.032 respectively) between the two groups. Conclusion With the guidance of color Doppler ultrasound, the efficacy and safety of long pulse 1064 nmNd:YAG laser, intense pulsed light, and lauromacrogol injection in the treatment of infantile hemangioma have better outcomes compared to laser treatment alone without preoperative ultrasound examination.
文摘Objective To assess the prevalence of the bleeding complications in pacemaker implanted patients receiving different antiplatelet regimens, and the influence of each regimen on hospital stays after device implantation. Methods We prospectively enrolled 364 patients receiving the cardiac rhythm device implantations in Fuwai Hospital from July 2012 to December 2013. Bleeding complications including pocket hematoma, hemothorax, cardiac tamponade and blood transfusion requirement were measured as endpoints. Post operation hospital stay was also included in the endpoints. Results Bleeding complications were detected in 15 patients (14 with hematoma, one with hemothorax) out of all 364 patients (4.12%). Dual antiplatelet therapy (DAT) significantly increased hematoma (19.3%) compared with aspi- fin treatment (ASA) (3.2%, P = 0.001) and no antiplatelet therapy (1.9%, P 〈 0.001). There was no significant difference in incidence of pocket hematoma between the ASA group and the control group (P = 0.45). The post procedure hospital stay was longer in DAT group (5.45 ± 2.01 days) compared to those in the ASA group (3.65 ± 1.37 days, P 〈 0.05) or control group (3.99 ± 2.27 days, P 〈 0.05). Pocket hema- toma was considered an independent predictor of hospital stay prolongation (OR: 5.26; 95% CI: 1.56-16.64; P = 0.007). Conclusions Among the Chinese patients undergoing device implantation in this study, the use of dual antiplatelet agents significantly increased the risk of pocket hematoma complications and led to a longer hospital stay. Use of aspirin alone did not increase the risk.
文摘Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into two groups. Anticoagulation group( Group A) consisted of 71 patients who were given heparin intravenously with target aPTT 50 - 70 seconds. Non-anticoagulation group( Group B) consisted of 82 patients without intravenous heparin during balloon pumping. Hematological parameters including platelet count, D-dimer, Plasminogen activator inhibitor-1 (PAI-1) and fibrinogen degradation products(FDP) were checked respectively at the point of baseline, 24 hours, 48 hours and 24 hours post IABP counterpulsation. Clot deposits on balloon surface, vascular complications from IABP including bleeding and limb ischemia were recorded.Results: Platelet count and PAI-1 level decreased at 24 hours and 48 hours in both groups ( P < 0.05) . D-dimer and FDP level increased at 24 hours and 48 hours in both groups( P < 0.05), but returned to the baseline level 24 hours post IABP removal( P > 0.05) . Three patients in Group A and 2 patients in Group B developed minor limb ischemia( P > 0.05). No major limb ischemia in either group. Two patients in Group A suffered major bleeding and required blood transfusion or surgical intervention, whereas no patient had major bleeding in Group B. Eight patients had minor bleeding in Group A, but only 2 patients in Group B ( P <0.05). No clot deposit developed on IABP surface in either group. Conclusion: IABP is safe without routine anticoagulation therapy. Selecting appropriate artery approach and early detection intervention are key methods for preventing complications.
文摘Photoplethysmogram(PPG)is a noninvasive method for detecting human cardiovascular pulse wave using optical technology.The PPG containing a lot of physiological information is from the MIMIC database.This paper proposes a combinatorial method of ensemble empirical mode decomposition(EEMD),cepstrum,fast Fourier transform(FFT)and zero-crossing detection to improve the robustness of the estimation of pulse rate(PR),heart rate(HR)and respiratory rate(RR)from the PPG.First,the PPG signal was decomposed into finite intrinsic mode functions(IMF)by EEMD.Because of its adaptive filtering property,the different signals were reconstructed using different IMFs when estimating different physiological parameters.Second,the PR was obtained by zero-crossing detection after rejecting low frequency IMFs containing artifacts.Third,IMFs with frequency between 1.00 Hz to 1.67 Hz(60 beats/min to 100 beats/min)were selected for estimating HR.Then,the frequency band that reflects the heart activity was analyzed by the cepstrum method.Finally,the respiratory signal can be extracted from PPG signal by IMFs with frequency between 0.05 Hz to 0.75 Hz(3 breahts/min to 45 breaths/min).Then the spectrum of signal was obtained by FFT analysis and the RR was estimated by detecting the maximum frequency peak.The algorithm has been tested on MIMIC database obtained from 53 adults.The experiment results show that the physiological parameters extracted by this integrated signal processing method are consistent with the real physiological parameters.And the computation load of this method is small and the precision is high(not larger than 1.17%in error).
文摘Objective: To study the regulation of blood pulse volume via photoplethysmography (PPG) signal detected from toe, while the lower limb is passively raised in different height positions. Methods: Use a modified non-invasive PPG technique to detect the blood pulse signal on toe with infrared (IR) photo sensor. A protocol consisting of two postures, i.e., supine and 45° reclining, was designed to conduct laboratory trial in this study. During the period of performing the protocol of these postures, the lower limb was passively raised from the heights of 10 cm to 60 cm randomly and individually with sponge blocks underneath the foot. Results: In the supine posture, the higher the foot was passively raised, the more the blood PPG signal decreased. In the 45° reclining posture, the blood PPG signal increased at the beginning and then decreased in the foot height position from 10 cm to 60 cm. In both postures the normalized AC signal changes significantly while the normalized DC signal changes little. Conclusion: The toe PPG signals can obviously indicate the regulated blood volume change with the designated postural procedures due to the heart level position.
基金Supported by the Foundation of the National New Drug Research of China, No. 96-901-05-197
文摘AIM: To investigate the effects and mechanisms of Verapamil on cultured human colonic tumor (HCT) cells.METHODS: HCT cells were treated with different concentrations of Verapamil, and their proliferation was examined by MTT assay. The areas of sub-diploid peak were measured by flow cytometry, and the DNA ladder was found by agarose gel electrophoresis. The characteristic changes in morphology were observed under light microscopy. The cell nuclei (propidium iodide labeled, PI-labeled) and cellular distribution and concentration of calcium (Fluo-3-labeled) were studied by using laser confocal scanning microscope.RESULTS: The proliferation of HCT cells was inhibited by different concentrations of Verapamil. With the increase in concentration of Verapamil, the percent of G0-G1 phase cells in HCT cells increased and that of S phase cells decreased. After treating with different concentrations of Verapamil, flow cytometry showed that HCT cells were enlarged in areas of sub-diploid in a dose-dependent manner. Gel electrophoresis results displayed a typical DNA ladder. On staining with Wrights-Giemsa, the typical cellular apoptosis morphologic changes were also observed. PI-labeled cell nuclei were found markedly changed. In addition, we inspected that the 100 μmol/L Verapamil could increase the intracellular calcium ion concentration [Ca2+]i in HCT cells.CONCLUSION: Verapamil can inhibit proliferation of HCT cells via inducing cell apoptosis.
基金Project(60503027) supported by the National Natural Science Foundation of China
文摘A kind of structure and a design method using transmission voltage-switch theory for pulse-triggered flip-flops were proposed,which are suitable for all kinds of pulse-triggered flip-flops and no extra techniques are needed to eliminate the switching activities of internal nodes.Based on the proposed structure and design technique,two pulsed flip-flops were implemented and simulated.The proposed pulsed flip-flops have simple circuit structures.HSPICE simulation shows that the proposed pulsed D flip-flop outperforms the conventional pulsed D flip-flop by 17.2% in delay and 30.1% in power-delay-product(PDP) and the proposed pulsed JK flip-flop has low power and small PDP compared with pulsed D pulsed flip-flops,confirming that the proposed structure and design technique are simple and practical.
文摘Objective To evaluate left univentricular (LUV) pacing for cardiac resynchronization therapy (CRT) using a rate-adaptive atrioven- tricular delay (RAAVD) algorithm to track physiological atrioventricular delay (AVD). Methods A total of 72 patients with congestive heart failure (CHF) were randomized to RAAVD LUV pacing versus standard biventricular (BiV) pacing in a 1 : 1 ratio. Echocardiography was used to optimize AVD for both groups. The effects of sequential BiV pacing and LUV pacing with optimized A-V (right atrio-LV) delay using an RAAVD algorithm were compared. The standard deviation (SD) of the S/R ratio in lead VI at five heart rate (HR) segments (Rs/R-SD5), defined as the "tracking index," was used to evaluate the accuracy of the RAAVD algorithm for tracking physiological AVD. Results TheQRS complex duration (132 ± 9.8 vs. 138± 10ms, P 〈 0.05), the time required for optimization (21 ±5 vs. 50±8min, P〈 0.001), the mitral regurgitant area (1.9 ± 1.1 vs. 2.5 ± 1.3 em2, P 〈 0.05), the interventricular mechanical delay time (60.7 ± 13.3 ms vs. 68.3 ± 14.2 ms, P 〈 0.05), and the average annual cost (13,200 ± 1000 vs. 21,600 ± 2000 RMB, P 〈 0.001) in the RAAVD LUV pacing group were significantly less than those in the standard BiV pacing group. The aortic valve velocity-time integral in the RAAVD LUV pacing group was greater than that in the standard BiV pacing group (22.7 ± 2.2 vs. 21.4 ± 2.1 cm, P 〈 0.05). The Rs/R-SD5 was 4.08 ± 1.91 in the RAAVD LUV pacing group, and was significantly negatively correlated with improved left ventricular ejection fraction (LVEF) (ALVEF, Pearson's r = -0.427, P = 0.009), and positively correlated with New York Heart Association class (Spearman's r - 0.348, P 0.037). Conclusions RAAVD LUV pacing is as effective as standard BiV pacing, can be more physiological than standard BiV pacing, and can de- crease the average annual cost of CRT.