• Title/Summary/Keyword: external heart

Search Result 188, Processing Time 0.028 seconds

Finite Element Analysis of Stent Expansion Considering Stent-Balloon Interaction (스텐트와 풍선의 상호작용을 고려한 스텐트 팽창의 유한요소해석)

  • Oh Byung-Ki;Cho Hae-Yong
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.29 no.1 s.232
    • /
    • pp.156-162
    • /
    • 2005
  • Stouts are frequently used throughout the human body, but the most critical areas are in coronary arteries. They open pathways in vessels and supply blood directly to the heart muscle. To simulate behavior of expansion for the coronary stent by balloon, the commercial finite element code LS-DYNA and ANSYS were used in the analysis. The explicit method is used to analyze the expansion of the stent and the implicit method is performed to simulate the springback that developed in a stent after the balloon pressure has been removed. Finally the experimental results for the expansion of the PS153 stents were compared with the FEM results. The springback was measured with the stents subjected to no external pressure to which stents are subjected in vivo. The simulated results were in good agreement with experimental results. Standard mechanical characteristics such as stress, plastic strains, and springback can be derived from the numerical results. These data can be used to determine maximum expansion diameter without fracture and expansion pressure considering elastic recoil.

A Study on the Temperature Dependence of PPG Measurement Devices (PPG 측정 장치에서의 온도 영향에 대한 연구)

  • Kim, Namsub
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.12 no.3
    • /
    • pp.306-311
    • /
    • 2019
  • This paper presents the temperature dependence of transmission-type and reflection-type PPG measurement devices that have been developed in the previous research. PPG signal can be distorted by external temperature such as skin temperature so that many of research was focused on the skin temperature effect. However, this paper focuses on the temperature of the device itself and we studied on the effect of device internal temperature. Experimental results showed that the temperature was increased like an irrational function graph and the transmission-type was not affected by the internal temperature but the reflection-type was affected by the internal temperature.

Comparative study on patterns and symptoms of disharmony(病機病症) between the internal organs(藏府) and external bodily form(身形) (藏府와 身形의 病機 및 病症에 대한 比較考察)

  • Baek, Sang-Ryong
    • Journal of Korean Medical classics
    • /
    • v.13 no.2 s.17
    • /
    • pp.21-21
    • /
    • 2000
  • All living things including human being consist of soul(spirit) and body. Soul is the root of a life and body frames it. I wrote this paper to tell how internal injury due to endogenous etiological factors and affection due to exegenous pathogenic factors, affect the internal organs and the external bodily from. This paper begins with description of the patterns of disharmony of the internal organs. General disorders of each Five-Jang(五藏) an be classified into two types of soul and body. The Liver and the Heart which lead changing to Yang(陽) of vital energy, have close relationship with spiritual symptoms because spirit is related to Yang. The Lung, Kidneys, the Spleen which lead changing to m(陰) of vital energy, mainly connected with physical disorders because body is relatively close to m. The Five-Jang are ruled by the Five-Phases(五行) system and cause troubles with Oche(五體) and the nine body orifice. Otherwise the main function of the Six-Bu(六府) is to receive food, absorb the usuable portions, and transmit and excrete waste. Therefore they can cause such problems as abdominal pain, distention, difficulty in urination, and constipation. The spleen is responsible for sending Grain-Ki)穀氣) 내 that is closely connected with the six-Bu. The Gall bladder takes care of control of giving out spirit. That's why it presents many symptoms related to the spirit that is ruled by the Five-Jang. Patterns of disharmony of external bodily form is influenced by the state of Maridians. Bodily forms get divided into many parts by the function of six-meridians(六經) to which they belong. Six-meridians have their own function related to excretion, related to excretion, retention, and balance(開闔樞). If local bodily froms get affected by pernicious influences, the Meridians to which they are attached will lose harmony and connot fulfil their own functions. Because the meridian symtem unifies all parts of the body, the whole body will be under the influence of the affection although local parts of the bodily forms get affected. Therefore the symptoms of disharmony should be considered in a synthetic view. There are however, also cases which should be focused on the very meridian channels affected. Disorder within a Meridian generates derangement in the pathway make it not to benefit the muscles and skin belong to it. Because the meridians connect the interior organs with the exterior bodily form, they are influenced by each other.

Comparative study on patterns and symptoms of disharmony(病機病症) between the internal organs(藏府) and external bodily form(身形) (장부(藏府)와 신형(身形)의 병기(病機) 및 병증(病症)에 대한 비교고찰(比較考察))

  • Baek, Sang-Ryong
    • Journal of Korean Medical classics
    • /
    • v.13 no.2 s.17
    • /
    • pp.22-42
    • /
    • 2000
  • All living things including human being consist of soul(spirit) and body. Soul is the root of a life and body frames it. I wrote this paper to tell how internal injury due to endogenous etiological factors and affection due to exogenous pathogenic factors, affect the internal organs and the external bodily from. This paper begins with description of the patterns of disharmony of the internal organs. General disorders of each Five-Jang(五藏) an be classified into two types of soul and body. The Liver and the Heart which lead changing to Yang(陽) of vital energy, have close relationship with spiritual symptoms because spirit is related to Yang. The Lung, Kidneys, the Spleen which lead changing to m(陰) of vital energy, mainly connected with physical disorders because body is relatively close to m. The Five-Jang are ruled by the Five-Phases(五行) system and cause troubles with Oche(五體) and the nine body orifice. Otherwise the main function of the Six-Bu(六府) is to receive food, absorb the usable portions, and transmit and excrete waste. Therefore they can cause such problems as abdominal pain, distention, difficulty in urination, and constipation. The spleen is responsible for sending Grain-Ki(穀氣) so that is closely connected with the six-Bu. The Gall bladder takes care of control of giving out spirit. That's why it presents many symptoms related to the spirit that is ruled by the Five-Jang. Patterns of disharmony of external bodily form is influenced by the state of Meridians. Bodily forms get divided into many parts by the function of six-meridians(六經) to which they belong. Six-meridians have their own function related to excretion, related to excretion, retention, and balance(開闔樞). If local bodily forms get affected by pernicious influences, the Meridians to which they are attached will lose harmony and cannot fulfil their own functions. Because the meridian system unifies all parts of the body, the whole body will be under the influence of the affection although local parts of the bodily forms get affected. Therefore the symptoms of disharmony should be considered in a synthetic view. There are however, also cases which should be focused on the very meridian channels affected. Disorder within a Meridian generates derangement in the pathway make it not to benefit the muscles and skin belong to it. Because the meridians connect the interior organs with the exterior bodily form, they are influenced by each other.

  • PDF

$Na^{+}/Ca^{2+}$ Exchange System in Atrial Trabeculae and Vascular Smooth Muscle of the Rabbit (토끼 심방근 및 혈관 평활근에서의 $Na^{+}/Ca^{2+}$ 교환기전에 관한 연구)

  • Kim, Hee-Ju;Moon, Hyung-Ro;Earm, Yung-E;Ho, Won-Kyung
    • The Korean Journal of Physiology
    • /
    • v.22 no.1
    • /
    • pp.13-29
    • /
    • 1988
  • In order to elucidate the regulatory mechanism of intracellular calcium ion concentrations, contractions or contractures induced by $Na^{+}-removal$, calcium-application or ouabain-treatment as an index of $Na^+/Ca^{2+}$ exchange activity were studied in atrial muscle or vascular smooth muscle (aorta and renal artery) of the rabbit. The magnitude of low sodium contractures in atrial trabeculae increased with sigmoid shape when external sodium concentrations were reduced to sodium-free condition, whereas that of calcium contracture intensified in a parabolic pattern when external calcium concentrations were elevated to 8 mM. $Na^{+}-removal$ contractures were induced in a duration-dependent manner to $K^{+}-free$ exposure and same findings were observed with ouabain treatment. $Na^{+}-free$ contractures were not affected by verapamil treatment, but stimulated by $100{\mu}M\;Mn^{2+}$ and inhibited by high concentrations of $Mn^{2+}\;(2{\sim}8mM)$ in a dose-dependent manner. Ryanodine which is known to suppress the release of calcium from internal store abolished spontaneous twitch contractions induced by $K^{+}-free$ solution, but had no effect on the development $Na^{+}-free$ contractures. Na-free contractures were not always induced in vascular smooth muscle preparations. Contractures by $O\;mM\;Na^+$ were usually seen in aorta, but not often in renal artery.$50\;mM\;K^+$, noradrenaline (NA) and angiotensin II (AII) always evoked very large contraction in all preparations of vascular smooth muscle. Contractures developed by $O\;mM\;Na^+$ were not sensitive to verapamil treatment as in atrial trabeculae, but were abolished by $100{\mu}M\;Mn^{2+}$. In contrast to $Na^{+}-free$ contractures, $Mn^{2+}(100{\mu}M)$ had no effect on the contractures induced by NA or 50 mM$K^+$. Caffeine in the concentration of 10 mM evoked transient contracture in the distal renal artery. The rate of spontaneous relaxation in caffeine contracture was dependent upon the concentrations of external sodium, and had double component of relaxation when the rate of relaxation was plotted in the semilogarithmic scale of relative tension versus time. Especially late components of relaxation had more direct relation to $Na^+$ concentrations. It could be concluded that $Na^+/Ca^{2+}$ exchange mechanism in the heart has a large capacity, inhibited by $Mn^{2+}$ but not by verapamil and ryanodine, while $Na^+/Ca^{2+}$ exchange system in vascular smooth muscle has a very low capacity especially in small artery, inhibited by low concentration of $Mn^{2+}\;(100{\mu}M)$ but not affected by verapamil and ryanodine.

  • PDF

THE CURRENT STATUS OF BIOMEDICAL ENGINEERING IN THE USA

  • Webster, John G.
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1992 no.05
    • /
    • pp.27-47
    • /
    • 1992
  • Engineers have developed new instruments that aid in diagnosis and therapy Ultrasonic imaging has provided a nondamaging method of imaging internal organs. A complex transducer emits ultrasonic waves at many angles and reconstructs a map of internal anatomy and also velocities of blood in vessels. Fast computed tomography permits reconstruction of the 3-dimensional anatomy and perfusion of the heart at 20-Hz rates. Positron emission tomography uses certain isotopes that produce positrons that react with electrons to simultaneously emit two gamma rays in opposite directions. It locates the region of origin by using a ring of discrete scintillation detectors, each in electronic coincidence with an opposing detector. In magnetic resonance imaging, the patient is placed in a very strong magnetic field. The precessing of the hydrogen atoms is perturbed by an interrogating field to yield two-dimensional images of soft tissue having exceptional clarity. As an alternative to radiology image processing, film archiving, and retrieval, picture archiving and communication systems (PACS) are being implemented. Images from computed radiography, magnetic resonance imaging (MRI), nuclear medicine, and ultrasound are digitized, transmitted, and stored in computers for retrieval at distributed work stations. In electrical impedance tomography, electrodes are placed around the thorax. 50-kHz current is injected between two electrodes and voltages are measured on all other electrodes. A computer processes the data to yield an image of the resistivity of a 2-dimensional slice of the thorax. During fetal monitoring, a corkscrew electrode is screwed into the fetal scalp to measure the fetal electrocardiogram. Correlations with uterine contractions yield information on the status of the fetus during delivery To measure cardiac output by thermodilution, cold saline is injected into the right atrium. A thermistor in the right pulmonary artery yields temperature measurements, from which we can calculate cardiac output. In impedance cardiography, we measure the changes in electrical impedance as the heart ejects blood into the arteries. Motion artifacts are large, so signal averaging is useful during monitoring. An intraarterial blood gas monitoring system permits monitoring in real time. Light is sent down optical fibers inserted into the radial artery, where it is absorbed by dyes, which reemit the light at a different wavelength. The emitted light travels up optical fibers where an external instrument determines O2, CO2, and pH. Therapeutic devices include the electrosurgical unit. A high-frequency electric arc is drawn between the knife and the tissue. The arc cuts and the heat coagulates, thus preventing blood loss. Hyperthermia has demonstrated antitumor effects in patients in whom all conventional modes of therapy have failed. Methods of raising tumor temperature include focused ultrasound, radio-frequency power through needles, or microwaves. When the heart stops pumping, we use the defibrillator to restore normal pumping. A brief, high-current pulse through the heart synchronizes all cardiac fibers to restore normal rhythm. When the cardiac rhythm is too slow, we implant the cardiac pacemaker. An electrode within the heart stimulates the cardiac muscle to contract at the normal rate. When the cardiac valves are narrowed or leak, we implant an artificial valve. Silicone rubber and Teflon are used for biocompatibility. Artificial hearts powered by pneumatic hoses have been implanted in humans. However, the quality of life gradually degrades, and death ensues. When kidney stones develop, lithotripsy is used. A spark creates a pressure wave, which is focused on the stone and fragments it. The pieces pass out normally. When kidneys fail, the blood is cleansed during hemodialysis. Urea passes through a porous membrane to a dialysate bath to lower its concentration in the blood. The blind are able to read by scanning the Optacon with their fingertips. A camera scans letters and converts them to an array of vibrating pins. The deaf are able to hear using a cochlear implant. A microphone detects sound and divides it into frequency bands. 22 electrodes within the cochlea stimulate the acoustic the acoustic nerve to provide sound patterns. For those who have lost muscle function in the limbs, researchers are implanting electrodes to stimulate the muscle. Sensors in the legs and arms feed back signals to a computer that coordinates the stimulators to provide limb motion. For those with high spinal cord injury, a puff and sip switch can control a computer and permit the disabled person operate the computer and communicate with the outside world.

  • PDF

An Ethnographic Study on Middle aged Women's Hwa-Byung with Upper Limb Arthropathy (중년여성의 화병과 상지관절동통에 관한 문화기술지)

  • Kim, Mee-Young
    • Journal of East-West Nursing Research
    • /
    • v.13 no.2
    • /
    • pp.160-169
    • /
    • 2007
  • Background: Hwa-Byung is known as a specific Korean cultural syndrome which corresponds to DSM-IV(MMPI). Some Korean women who have experienced heart aching anger(Hwa-Byung) complain physical pains as well as psychological problems. As for these physical pains, upper limb arthropathy(e.g. golf elbow pains, tennis elbow pains, or shoulder-joint pains) have not been paid attentions. In spite of not having done her excessive physical endeavor or exercise, some Korean middle aged women complain those arthropathy pains. And they go round orthopedics, pain clinics, and oriental medicine clinics. Purpose: This study was practiced in Severance Oriental Medicine Clinic. The oriental medicine doctor had a question about the major origin of upper limb pains which were not caused by excessive physical endeavor. To answer the question, this study has been practiced. In the process of interview with some those women, the major cause of those syndromes has been revealed as Hwa-Byung. The purpose of this study is to discover the meanings of the women's life who have been experienced Hwa-Byung with upper limb arthropathy. Results: These upper limb arthropathy can be explained by meridian theory. Shoulder-joint pain and golf elbow with Hwabyung can be explained by Heart meridian of hand-shoyin and the points of these pains are in the flow of this meridian. Tennis elbow with Hwabyung can be explained by Small intestine meridian of hand-taiyang and this point is in the flow of this meridian. The results of interview with 9 middle aged women was analyzed and interpreted according to Spradley's method of ethnography. The analysis revealed three core cultural themes : 1) There are certainly external cause to provoke Hwa-Byung. A patricentric family system, husband's playing around with another woman, cruel treatment by husband's family, or financial failure may be present anteriorly. 2) The chief existing condition is the discord between husband and wife. The stoppage of mutual communication, lacking in understanding, unfeeling, heartless, or unsympathetic is an major phenomenon of married life. So the important factor is not the sexual relations or problems but the discords of communication. 3) The feeling of anger, the sense of nihility, the desire to escape, and the effort to forgiveness coexist together. At a glance, they seemed to be a process. For example, anger seemed to present at first, then nihility seemed at second, then escape seemed at third, and then forgiveness seemed at last. But at point of visiting clinic to be treated, they are mixed up together as if in a jumble.

  • PDF

Review of Clinical Research Literatures on Effect of Traditional Chinese Medicine for Pediatric Night Crying (야제 (夜啼)의 한의학 치료에 대한 최신 중의학 임상 연구 동향 -2000년대 이후 발표된 임상 연구 논문을 중심으로-)

  • Kim, Sang Min;Lee, Jin Yong;Lee, Sun Haeng;Doh, Tae Yun
    • The Journal of Pediatrics of Korean Medicine
    • /
    • v.32 no.3
    • /
    • pp.100-118
    • /
    • 2018
  • Objectives The purpose of this study is to analyze some of the TCM (traditional Chinese medicine) clinical research literatures about pediatric night crying in order to learn clinical application of Korean medicine treatment for pediatric night crying. Methods We searched clinical trial literatures about TCM treatment of pediatric night crying from the CNKI (China National Knowledge Infrastructure) (January 2000 to June 2018). We analyzed the literature in regards to the treatment methods and the results. Results Among the 459 searched studies, 13 randomized controlled trials and 41 case studies were selected and analyzed. In most of the studies, the effectiveness of TCM in treating patients was significantly high, so we confirmed the effectiveness of TCM on pediatric night crying. The most commonly used pattern differentiations (辨證) were Spirit damage due to fright and fear (驚恐傷神), Spleen deficiency and cold (脾虛寒) and Heart fire heat (心火熱). Methods of treatment include herbal medicines (internal medicine and external application), massage therapy (Tuina methods), acupuncture and other treatments (bloodletting). The most commonly used herb medicines were Cicadidae Periostracum (蟬?), Poria Cocos (茯?), Glycyrrhizae Radix (甘草), Uncariae Ramulus et Uncus (釣鉤藤), Junci Medulla (燈心草), Fossilia Ossis Mastodi (龍骨), Atractylodis Rhizoma Alba (白朮), Cinnabaris (朱砂), and Coptidis Rhizoma (黃連). The most commonly used massage methods were Clearing Liver Channel (淸肝經), Clearing Heart Channel (淸心經), Kneading $Xi{\check{a}}oti{\bar{a}}nx{\bar{i}}n$ (?小天心), Supplementing Spleen Channel (補脾經), Clearing $Ti{\bar{a}}nh{\acute{e}}shu{\check{i}}$ (淸天河水), and Rubbing Abdomen (摩腹). Conclusions Based on the results of clinical studies from China, the use of Korean medicine for the treatment of pediatric night crying has been shown to be effective in relieving symptoms. Based on the results of this study, it is possible to widen the scope of Korean medicine by additionally reviewing clinical and experimental studies on pediatric night crying.

Architectural Refactoring of Real-Time Software Design for Predictable Controls of Artificial Heart (인공심장의 예측 가능한 제어를 위한 실시간 소프트웨어 설계 구조의 개선)

  • Jeong, Se-Hun;Kim, Hee-Jin;Park, Sang-Soo;Cha, Sung-Deok
    • The KIPS Transactions:PartA
    • /
    • v.18A no.6
    • /
    • pp.271-280
    • /
    • 2011
  • Time-Triggered Architecture (TTA), one of real-time software design paradigms which executes tasks in timely manner, has long been advocated as being better suited in fore-sighting system behavior than event-triggered architecture (ETA). To gain this valuable feature of TTA, however, precise task designing process is mandatory. Alternatively, ETA tries to execute tasks whenever paired events are occurred. It provides intuitive and flexible basement to add/remove tasks and, moreover, better response time performance. However ETA is difficult to analyze because system behavior might be different depending on the order of interrupts detected by the system. Many previous researches recommended TTA when developing safety-critical real-time systems, but cost problem of task designing process and insufficient consensus for applying rigorous software engineering practice are still challenging in practice. This paper describes software refactoring process which applying TTA approach into ETA based embedded software in artificial heart system. We implemented dedicated interrupt monitoring program to capture existing tasks' real-time characteristics. Based on the captured information, proper task designing process is done. Real-time analysis using RMA (Rate-Monotonic Analysis) verified that new design guarantees timeliness of the system. Empirical experiments revealed that revised design is as efficient, when measured in terms of system's external output, as the old design and enhances predictability of the system behavior as well.

ORTHODONTIC TRACTION OF IMPACTED POSTERIOR TEETH : CASE REPORTS (매복 구치부 치아의 교정적 이동 : 증례 보고)

  • Maeng, Yu-Jin;Oh, So-Hee
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.36 no.4
    • /
    • pp.613-618
    • /
    • 2009
  • Impacted molars are not usual with the prevalence rate of less than 1%, however problems such as infraocclusion, extrusion of the opposite tooth and lack of space are caused. If molars are impacted, radiographic check-up and observations are needed as they play an important role in skeletal development and mastication. Causes of impaction are underdevelopment of roots, supernumerary teeth, cysts, odontomas, ankylosis and etc. In our first case, we present impacted molar which was surgically exposed and orthodontically traded. As the developmental state of the root was less than half at first visit, we observed until the root was 2/3 in its length and traction was carried out. The second case is orthodontic traded molar with compleate enucleation of the existing cysts. When trading impacted molars, direct bonding of attachments to the tooth and light continuous forces are recommended so as to ankylosis, external absorption and periodontal attachment loss avoid. Fixed appliances tract the teeth on arch and obtain eruption spaces without patient's cooperation. We report surgically exposed and orthodontically traded molars which resulted in good occlusion and patients satisfaction.

  • PDF