• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.45-53
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• 2003

Based on the 4-compartmental pharmacokinetic model developed in PART1, target-controlled infusion(TCI) pump system was designed and evaluated. The TCI system consists of digital board including microcontroller and digital signal process(DSP), analog board, motor-driven actuator, user friendly interface, power management and controller. It provides two modes according to the drugs: plasma target concentration and effect target concentration. Anaesthetist controls the depth of anaesthesia for patients by adjusting the required concentration to maintain both plasma and effect site in drug concentration. The data estimated in DSP include infusion rate, initial load dose, and rotation number of motor encoder. During TCI operation, plasma concentration. effect site concentration, awaken concentration, context-sensitive decrement time and system error information are displayed in real time. Li-ion battery guarantees above 2 hours without power line failure. For high reliability of the system, two microprocessors were used to perform independent functions for both pharmacokinetic algorithm and motor control strategy.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.3
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• pp.165-173
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• 2016

Dentists often sedate patients in order to reduce their dental phobia and stress during dental treatment. Sedatives are administered through various routes such as oral, inhalation, and intravenous routes. Intravenous administration has the advantage of rapid onset of action, predictable duration of action, and easy titration. Typically, midazolam, propofol or dexmedetomidine are used as intravenous sedatives. Administration of these sedatives via infusion by using a syringe pump is more effective and successful than infusing them as a bolus. However, during intravenous infusion of sedatives or opioids using a syringe pump, fatal accidents may occur due to the clinician's carelessness. To prevent such risks, smart syringe pumps have been introduced clinically. They allow clinicians to perform effective sedation by using a computer to control the dose of the drug being infused. To ensure patient safety, various alarm features along with a drug library, which provides drug information and prevents excessive infusion by limiting the dose, have been added to smart pumps. In addition, programmed infusion systems and target-controlled infusion systems have also been developed to enable effective administration of sedatives. Patient-controlled infusion, which allows a patient to control his/her level of sedation through self-infusion, has also been developed. Safer and more successful sedation may be achieved by fully utilizing these new features of the smart pump.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.4
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• pp.217-226
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• 2019

Background: We aimed to assess the dose needed to achieve the propofol effect-site concentration using target-controlled infusion in intellectually disabled patients and to detail the most effective method for achieving a safe level of consciousness without hemodynamic changes as well as detail any resulting adverse effects. Methods: We performed a retrospective review of sedation service records of 138 intellectually disabled patients (51, mental retardation; 36, autism; 30, brain lesion, 12 genetic diseases, 9 dementia) aged over 15 years and weighing over 30 kg. These patients had received propofol via target-controlled infusion in the special care dental clinic of Seoul National University Dental Hospital from May 2008 to September 2018 for restorative treatment (112), minor surgery (13), prosthodontics (7), periodontics treatment (5), and implant (1). Results: For all groups, the duration of dental treatments was $43{\pm}18$ minutes, total sedation time was $73{\pm}23$ minutes, and total BIS values was $57{\pm}12$. The propofol maintenance dosage values for each group were: mental retardation, $3{\pm}0.5(2-4){\mu}g/ml$; autism, $3.1{\pm}0.7(2-5){\mu}g/ml;$; brain lesion, $2.8{\pm}0.7(1.5-5){\mu}g/ml;$; genetic disease, $2.9{\pm}0.9(1-4){\mu}g/ml;$ and dementia $2.3{\pm}0.7(1-3.4){\mu}g/ml;$. Conclusions: The dementia group needed a lower dosage to reach a safe, effective propofol effect-site concentration than the other groups. Since there were no complications, deep sedation is a great alternative to general anesthesia for dental treatment of intellectually disabled patients.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.186-189
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• 2005

In a clinical setting, developing a reliable method for the automated drug infusion system would improve a drug therapy under the unexpected and acute changes of hemodynamics. The conventional proportional-integral-derivative (PID) controller might not be able to achieve maximum performance because of the unexpected change of the intra- and inter-patient variability. The fuzzy PID control and the conventional PID control were tested under the unexpected response of mean arterial blood pressure (MAP) to a vasopressor agent during acute hypotension. Compared with the conventional PID control, the fuzzy PID control performed the robust MAP regulation regardless of the unexpected MAP response (average absolute value of the error between target value and actual MAP: 0.98 vs. 2.93 mmHg in twice response of the expected MAP and 2.59 vs. 9.75 mmHg in three-times response of the expected MAP). The result was due to the adaptive change of the proportional gain in PID parameters.

• Journal of Biomedical Engineering Research
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• v.23 no.5
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• pp.341-349
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• 2002

The target controlled infusion(TCI) pump system is a logical approach to the development of improved administration techniques of an intravenous anaesthetic agent. The principle of TCI system is based on an understanding of the pharmacokinetic properties, three or four compartment model. The TCI system is optimal and flexible control of the plasma drug concentration. But the clinical goal is always to achieve a therapeutic drug effect, not a therapeutic concentration. So we developed the algorithm to target the concentration at the site of drug effect rather than the concentration in the plasma. If impulse drug is inputted into body, the decline of plasma concentration with time is shown, resulting in the expression of the differential equation. Therefore, we must reformulate our three-compartment model as four-compartment model with the effect compartment. And we tested plasma targeting and effect targeting algorithm by computer simulation using four-compartment model. So we developed the TCI capable of applying all intravenous drugs by adjusting individual pharmacokinetic parameters independently.

• International Journal of Contents
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• v.11 no.2
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• pp.69-73
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• 2015

This study was performed to determine the optimal doses of alfentanil or remifentanil (effect-site concentrations) required to prevent pain and other suffering after abdominal general surgery in ICU patients. A total of 52 general abdominal surgical patients (ASA IIIII) requiring artificial ventilatory care in the ICU were provided with either alfentanil (24 patients) or remifentanil (28 patients) through target controlled infusion (TCI). Alfentanil and remifentanil concentrations were titrated up and down until the pain score became less than 3 (VAS; Visual Analogue Score < 3). The effect-site concentrations (ng/ml) of alfentanil or remifentanil required to adequately control postoperative pain in the ICU were 64 +/- 12 and 1.9 +/- 0.5 for intubation with artificial ventilation, 57 +/- 9 and 1.7 +/- 0.7 for intubation with spontaneous ventilation, and 41 +/- 10 and 1.2 +/- 0.5 after extubation, respectively. Pain scores and the corresponding opioid concentrations were independent from respiratory condition. The three effect-site concentrations of alfentanil and remifentanil obtained from this clinical trial using the TCI technique can be a guideline in the administration of the same opioids to relieve the discomfort of ICU patients who have undergone abdominal general surgery.

• Journal of Neurocritical Care
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• v.11 no.2
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• pp.81-85
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• 2018

Proper glucose management in hospitalized patients can improve clinical outcomes. In particular, intensive care unit (ICU) patients are known to have significantly higher rates of mortality from changes in blood glucose due to severe comorbidities. Improving glucose control in ICU patients, therefore, can improve mortality and prognosis. Several studies related to the management of blood glucose in the ICU patients have been conducted. Intensive glucose management of surgical ICU patients has been successful. However, studies on medical ICU patients did not demonstrate positive effects of strict glycemic control. There is no independent glucose management goal for neurological ICU patients. However, maintenance of the usual glucose control target of 140-180 mg/dL is recommended for ICU patients. Intravenous insulin infusion is essential for glucose control in ICU patients not consuming a regular diet, and caution should be exercised to prevent hypoglycemia.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.3
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• pp.217-222
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• 2016

Dental treatment is often performed under general anesthesia or sedation when an intellectually disabled patient has a heightened fear of treatment or has difficulty cooperating. When it is impossible to control the patient due to the severity of intellectual disability, conscious sedation is not a viable option, and only deep sedation should be performed. Deep sedation is usually achieved by propofol infusion using the target controlled infusion (TCI) system, with deep sedation being achieved at a slightly lower concentration of propofol in disabled patients. In such cases, anesthesia depth monitoring using EEG, as with a Bispectral Index (BIS) monitor, can enable dental treatment under appropriate sedation depth. In the present case, we performed deep sedation for dental treatment on a 27-year-old female patient with mental retardation and severe dental phobia. During sedation, we used BIS and a newly developed Anesthetic Depth Monitor for Sedation (ADMS$^{TM}$), in addition to electrocardiography, pulse oximetry, blood pressure monitoring, and capnometry for patient safety. Oxygen was administered via nasal prong to prevent hypoxemia during sedation. The BIS and ADMS$^{TM}$ values were maintained at approximately 70, and dental treatment was successfully performed in approximately 30 min.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.3
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• pp.173-179
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• 2015

Issues related to the control of seizures and bleeding, as well as behavioral management due to mental retardation, render dental treatment less accessible or impossible for patients with Sturge-Weber syndrome (SWS). A 41-year-old man with SWS visited a dental clinic for rehabilitation of missing dentition. A bilateral port-wine facial nevus and intraoral hemangiomatous swollen lesion of the left maxillary and mandibular gingivae, mucosa, and lips were noted. The patient exhibited extreme anxiety immediately after injection of a local anesthetic and required various dental treatments to be performed over multiple visits. Therefore, full-mouth rehabilitation over two visits with general anesthesia and two visits with target-controlled intravenous infusion of a sedative anesthesia were planned. Despite concerns regarding seizure control, bleeding control, and airway management, no specific complications occurred during the treatments, and the patient was satisfied with the results.

• Journal of Chest Surgery
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• v.35 no.4
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• pp.267-273
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• 2002

Background: We performed a phase IV clinical trial to examine the usefulness of a continuous infusion of nicardipine hydrochloride to control hypertension in patients with acute aortic dissection. material and Method: Systolic/diastolic blood pressure, and heart rate were monitored before and after the intravenous administration of nicardipine in 31 patients with aortic diseases. The period of nicardipine administration in each patient was from 3 to 14 days. Efficacy was evaluated by determining the average amount of blood pressure reduction on the 3rd day of drug administration. The dosage of another antihypertensive agent was slowly tapered down, and ultimately replaced by the test drug. Result: 28 patients were diagnosed as acute aortic dissection, 2 patients as rupture of the aortic arch aneurysm, and 1 patient as traumatic aortic rupture. Mean age was 53.9 $\pm$ 14.9(29~89) years, and 21 patients(67.7%) were male. 14 patients(32.3%) had complications associated with underlying aortic disease: aortic insufficiency in 7, hemopericardium in 6, acute renal failure in 1, paraplegia in 1, lower extremity ischemia in 1, and hemothorax in 1. The time needed to reach the target blood pressure was within 15 minutes in 16, from 15 to 30 minutes in 10, from 30 to 45 minutes in 3 and from 45 to 60 minutes in 2, and their baseline average systolic, diastolic, and mean arterial blood pressures(mmHg) were 147$\pm$23, 82.3$\pm$ 18.6, and 104 $\pm$ 18, respectively. Average systolic, diastolic, and mean arterial blood pressures(mmHg) on the third day of nicardipine infusion were 119$\pm$ 12, 69$\pm$9, and 86$\pm$8, and they all showed statistically significant decrease(p<0.05). The average systolic, diastolic, and mean arterial blood pressure(mmHg) after the discontinuation of the nicardipine infusion were 119 $\pm$ 15, 71 $\pm$ 14, and 86$\pm$ 13, respectively. No significant difference was observed between the average pressures measured on the third day and those measured after the discontinuation of the nicardipine infusion, and no definite side effects were observed during the study period. Conclusion: Nicardipine hydrochloride was both effective and safe at controlling blood pressure in patients with acute aortic dissection.