• 반도체디스플레이기술학회지
• /
• 제20권1호
• /
• pp.7-11
• /
• 2021

The electrocardiogram(ECG) and heart rates are essential for diagnosing heart disease. However, conventional portable ECG devices are possible to only measure heart rates or have limitations in how and where they are measured. In this paper, a portable ECG system in which ECG waveforms and heart rates are displayed on smartphone screens is developed. A smartphone is used as display equipment instead of a computer screen for continuous monitoring. The developed ECG system filters and amplifies detected analog ECG signals. Next, it converts the amplified analog ECG signals into digital signals, then transmits to the smartphone via Bluetooth communication. This ECG system can display and store biomedical signals on a smartphone through the application. As a result, the waveform and heart rates of the developed portable ECG system has been confirmed to be similar to those of existing medical devices.

• Journal of Yeungnam Medical Science
• /
• 제6권1호
• /
• pp.99-107
• /
• 1989

저자들은 1987년 9월부터 1989년 4월사이 약 19개월간 영남대학병원 내과에 입원하여 만성 심방세동 진단하에 치료받고 있던 환자 34명을 대상으로 digoxin치료를 받은 20명과 치료를 받지 않은 10명에 대한 24시간 ambulatory ECG를 시행하여 두 집단간의 심박수의 변화 및 가장 긴 정지기등을 비교 분석한 결과 다음과 같은 성적을 얻었다. 1) 대상환자 34례의 평균 심박수의 평균치는 $75.7{\pm}13.8$회/min.($mean{\pm}S.D.$), 가장 빠른 심박수는 $148.0{\pm}32.4$/min.($mean{\pm}S.D.$), 가장 느린 심박수는 $48.1{\pm}8.4$회/min.($mean{\pm}S.D.$)이었고 가장 빠른 심박수와 가장 느린 심박수의 차이의 평균치는 $99.9{\pm}29.0$회/min.($mean{\pm}S.D.$), 가장 긴 정지기는 $2.95{\pm}1.06sec.$($mean{\pm}S.D.$)이었으며 이중 4명은 가장 긴 정지기가 4.0sec.이상으로 sick sinus syndrome을 배제할 수 없어서 비교대상집단에서는 제외시켰다. 2) 대상환자 34례중 27례에서 심실성 기외수축이 있었으며 100회/24hours이내가 11례(40.7%)로 가장 많았고, 변성전도(aberrant conduction)는 전례에서 다 나타났다. 3) Digoxin(0.25mg/day)으로 치료받은 20례의 평균 심박수의 평균치는 $78.4{\pm}13.7$회/min.($mean{\pm}S.D.$), 가장 빠른 심박수는 $152.5{\pm}33.1$회/min.($mean{\pm}S.D.$), 가장 느린 심박수는 $48.9{\pm}8.5$회/min.($mean{\pm}S.D.$) 이었고 가장 빠른 심박수와 가장 느린 심박수의 평균치는 $103.6{\pm}31.7$회/min.($mean{\pm}S.D.$), 가장 긴 정지기는 $2.55{\pm}0.50$sec.($mean{\pm}S.D.$)이었다. 4) Digoxin으로 치료받지 않은 10례의 평균 심박수의 평균치는 $78.0{\pm}10.7$회/min.($mean{\pm}S.D.$), 가장 빠른 심박수는 $154.5{\pm}26.8$회/min($mean{\pm}S.D.$), 가장 느린 심박수는 $50.6{\pm}7.1$회/min.($mean{\pm}S.D.$)이었고 가장 빠른 심박수와 가장 느린 심박수의 평균치는 $103.9{\pm}22.2$회/min.($mean{\pm}S.D.$), 가장 긴 정지기는 $2.66{\pm}0.39sec.$($mean{\pm}S.D.$)이었다. 5) Digoxin으로 치료받은 20명과 치료받지 않은 10명의 두 집단간의 평균 심박수, 가장 빠른 심박수, 가장 느린 심박수, 가장 빠른 심박수와 가장 느린 심박수의 차이, 가장 긴 정지기의 차이는 통계학적으로 유의하지 않았다(P>0.05). 이상을 요약하면 하루 0.25mg의 digoxin투여로 만성 심방세동 환자의 심박수는 잘 조절되었으며 만성 심방세동 환자의 치료유무 결정 및 치료약제에 대한 반응등을 평가하는데 ambulatory ECG가 유용하고 안전한 검사법으로 사료된다.

• 대한의생명과학회지
• /
• 제19권3호
• /
• pp.254-260
• /
• 2013

The purpose of this study was to survey the effects of Karvonen exercise prescription in coronary artery disease patients reaching age-predicted maximal heart rates with the exercise stress test on hemodynamic responses and cardiorespiratory fitness. The subject group was comprised of acute coronary syndrome (ACS) patients, who were divided into the maximal heart rate (MHR) group that included those who completed the test with their heart rates reaching the number of 220-age and the maximal dyspnea (MD) group that included those who could not continue the test due to respiratory difficulty and were asked to stop the test. Both groups had the exercise stress test before and after the experiment. In the exercise stress test before the experiment, the exercise prescription intensity of Karvonen was set at the target heart rates of 50~85% with a six-week exercise monitoring arrangement. As a result, there were no interactive effects in rest heart rate (RHR) according to time and group, but interactive effects were observed in maximal heart rate (MHR) (P=0.000). Both rest systolic blood pressure (RSBP) and rest diastolic blood pressure (RDBP) had no interactive effects according to time and group. Maximal systolic blood pressure (MSBP) showed significant interactive effects according to time and group (P=0.017). Maximal diastolic blood pressure (MDBP) showed no interactive effects according to time and group, while maximal rate pressure product (MRPP) showed significant interactive effects according to time and group (P=0.003). Maximal time (MT) had no interactive effects according to time and group. $VO_{2max}$ and maximal metabolic equivalent (MMET) showed significant interactive effects according to time and group (P=0.000, P=0.002, respectively), whereas maximal respiratory exchange ratio (MRER) and maximal rating of perceived exertion (MRPE) showed no interactive effects according to time and group. The exercise test that was discontinued as the subjects reached the predicted maximal heart rates considering age did not reach the maximal exercise intensity and accordingly showed low exercise effects when applied to Karvonen exercise prescription intensity. That is, the test should keep going by monitoring cardiac events, MRER and MRPE until the heart rates exceed the predicted MHR by up to 10~12 even after the subject reaches the predicted MHR considering age in the exercise stress test.

• 한국산업보건학회지
• /
• 제29권3호
• /
• pp.368-374
• /
• 2019

Objectives: To examine the associations of borg's scale with actual heart rates of workers and energy consumption during their physical work. Methods: A total of 72 workers performing physical activities in postal service, ceramic manufacturing, and metal manufacturing participated in heart rate measurement for 1 work shift using the activity meter(A360) and responded to a borg's scale questionnaire. Results: In consistent with previous findings, we presented high correlation between borg's scale and energy consumption measures among workers performing physical activities(r=0.89) while post-work average heart rate showed nearly no correlation with post-work borg's scale (r=0.09). We proposed a set of adjustments when using borg's scale to estimate physical workload for those workers engaged in physical activities during the majority of their work shift. Conclusions: Our findings suggest that a caution should be paid to when using Borg's scale to estimate heart rates during physical activities as well as energy consumption as the product of heart rate measurements.

• 대한의용생체공학회:의공학회지
• /
• 제35권6호
• /
• pp.177-184
• /
• 2014

Continuous monitoring of heart rates and respiratory rates for newborns or infants is very important since the abnormal breathing and heart problems can threaten the life of newborns or infants. A noncontact baby monitoring system based on a Doppler radar and an air mattress was designed. The Doppler radar was used to acquire respiratory signals and the air mattress was employed to obtain heart rates. The performance of the designed system was evaluated using a commercialized infant simulator ($Simbaby^{TM}$) and a respiration belt transducer was used to measure respiration rates as a reference. Results for respiratory rates revealed that the correlation coefficients between I-and Q-channel and the respiration belt were 0.84 and 0.91 and the mean ${\pm}$ standard deviations of errors between them were $1.66{\pm}1.92$ (bpm) and $0.88{\pm}1.65$ (bpm). Heart rates showed that the correlation coefficient between air mattress and set value of the simulator was 0.73 and the mean ${\pm}$ standard deviation of errors between them was $1.09{\pm}3.45$ (bpm). These results indicate that the designed system holds the potential as an effective monitoring tool for continuous monitoring heart rates and respiratory rates of newborns or infants.

• Journal of Chest Surgery
• /
• 제44권6호
• /
• pp.413-417
• /
• 2011

Background: Sleeve lobectomy for lung cancer in close proximity to or involving the carina is widely accepted. Operative morbidity and mortality rates, recurrence, and survival rates have varied considerably across studies. Materials and Methods: From March of 2005 to July of 2010, sleeve lobectomy was performed in 19 patients and pneumonectomy was performed in 20 patients. In this paper, the results of sleeve lobectomy and pneumonectomy for patients with lung cancer will be compared and evaluated. Results: There were no postoperative complications in either group, but there was one mortality in the pneumonectomy group. There was better preservation of pulmonary function in the sleeve lobectomy group than the pneumonectomy group (p=0.066 in FVC, p=0.019 in FEV1). The 3-year survival rates were 46.7% in the sleeve lobectomy group and 54.5% in the pneumonectomy group (p=0.505). The 3-year disease-free survival rates were 38% in the sleeve lobectomy group and 45.8% in the pneumonectomy group (p=0.200). Conclusion: Sleeve lobectomy for lung cancer showed low mortality, low bronchial anastomotic complication rates, and good preservation of pulmonary function.

• Journal of Acupuncture Research
• /
• 제19권1호
• /
• pp.147-158
• /
• 2002

Objective : The aim of the present study is to investigate the effect of stimulation on different sites of the body on MBP(mean blood pressure) and HR(heart rate). Methods : Six healthy men have participated in this study. Before and after 10 min, exercise on a running machine of l0km/hr, acupressure, plain acupuncture and electroacupuncture(50Hz) stimulation was practiced on GV20, LI4, ST36, BL40 and non-acupoints on T4 and T10 respectively for 20 min. and in a control group without any treatment. The changes of MBP and HR after exercise have been observed for 20 min. at 5 minute intervals. Results : Compared with control, no significant difference was observed in research of the blood pressure measurement regardless of methods nor sites of stimulation. But there were trends of reduction in the heart rates in all experimental groups. Especially, in the group of acupressure on T10 before exercise, GV20, T10 after exercise and electroacupuncture on GV20, LI4, BL40 after exercise there was statistically significant decreases in heart rates. Conclusion : From the present experiment, it is concluded that somatic stimulation has effect on the heart rates but not on the blood pressures, and the presence of effective sites on the decreases of heart rates suggest that this effect may depend on sites of stimulation.

• 한국운동역학회지
• /
• 제25권2호
• /
• pp.141-147
• /
• 2015

Objective : This study aimed to understand how increased heart rates at the time of drop landing during a step test would affect biomechanical variables of the lower extremity limbs. Background : Ballet performers do more than 200 landings in a daily training. This training raises the heart rate and the fatigability of the lower extremity limbs. Ballet performance high heart rate can trigger lower extremity limb injury. Method : We instructed eight female ballet dancers with no instability in their ankle joints(mean ${\pm}$ SD: age, $20.7{\pm}0.7yr$; body mass index, $19.5{\pm}1.2kg/m^2$, career duration, $8.7{\pm}2.0yr$) to perform the drop landing under the following conditions: rest, 60% heart rate reserve (HRR) and 80% HRR. Results : First, the study confirmed that the increased heart rates of the female ballet dancers did not affect the working ranges of the knee joints during drop landing but only increased angular speeds, which was considered a negative shock-absorption strategy. Second, 80% HRR, which was increased through the step tests, led to severe fatigue among the female ballet dancers, which made them unable to perform a lower extremity limb-neutral position. Hence, their drop landing was unstable, with increased introversion and extroversion moments. Third, we observed that the increasing 80% HRR failed to help the dancers effectively control ground reaction forces but improved the muscular activities of the rectus femoris and vastus medialis oblique muscles. Fourth, the increasing heart rates were positively related to the muscular activities of the vastus medialis oblique and rectus femoris muscles, and the extroversion and introversion moments. Conclusion/Application : Our results prove that increased HRR during a step test negatively affects the biomechanical variables of the lower extremity limbs at the time of drop landing.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
• /
• 제4권8호
• /
• pp.253-258
• /
• 2015

u-헬스케어 관점에서 볼 때, 심박수(heart rate)는 아픈 사람의 질환을 관리하는 일리스(illness)나 건강한 사람의 건강을 지속적으로 관리하는 웰니스(wellness) 분야에 모두 유용하게 사용된다. 이는 심박수가 질환의 증상을 판단하거나 운동 부하의 지표로서 모두 사용될 수 있기 때문이다. 최근에 착용형 센서(wearable sensors)를 이용하여 상시적으로 심박수를 모니터링하여 이에 기반하여 현재 몸 상태를 점검해볼 수 있는 다양한 심박계(heart rate monitor)와 이와 연동하여 심박수를 이용한 다양한 운동관리 스마트폰 앱이 개발되어 출시되고 있다. 그러나 이러한 스마트폰 앱은 모두 개인 용도로 제한된다. 논문에서는 여러 사람들의 심박수를 동시에 실시간으로 모니터링할 수 있는 시스템을 설계하고, 이를 적용할 수 있는 안드로이드 앱을 개발한다. 개발된 앱의 주요 기능은 다수 이용자에 대한 동시적 심박수 모니터링으로 피트니스 센터에 효과적으로 적용 가능하다.

• 한국환경생태학회지
• /
• 제9권1호
• /
• pp.49-55
• /
• 1995

본 연구는 계룡산 국립공원과 오대산 국립공원의 9개 등산로를 대상으로 등산로의 물리적 조건이 심장박동수에 미치는 영향을 밝히기 위하여 수행되었다. 산오르기 등산은 피검자가 에르고메타를 이용하여 측정한 최대심박수의 84~96%에 해당하는 고된 신체운동이며, 동일한 코스를 내려올 때의 최대심박수는 올라갈 때의 최대심박수에 약 78~93%에 해당하는 값을 나타내었다. 등산로의 경사도는 심박수에 영향을 미치는 것으로 나타났으나, 노폭은 심박수와 무관한 것으로 판단된다. 비시설 등산로에 비하여 나무 또는 돌계단식과 같은 등산로 노면재료가 심박수의 증가에 영향을 크게 미치는 것으로 나타났다.