• Journal of Biomedical Engineering Research
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• v.26 no.4
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• pp.193-197
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• 2005

Shunt valves used to treat patients with hydrocephalus were tested to investigate influence of intracranial pressure pulsation on their flow control characteristics. Five commercial shunt valves were tested in the flow loop that simulates pulsed flow under pressure pulsation. As 20cc/hr of flow rate was adjusted at a constant pressure, application of $40mmH_2O$ of pressure pulse increased the flow rate by $67.9\%.$ As a 90cm length catheter was connected to the valve outlet, increase in the flow rate was substantially reduced to $17.5\%.$ As the flow rate was adjusted to 40cc/hr at a constant pressure, increase in the flow rate was $51.1\%$ with the same pressure pulsation of $40mmH_2O$. The results indicated that pressure-flow control characteristics of shunt valves implanted above human brain ventricle is quite different from those obtained by syringe pump test at constant pressures right after manufacture. The influence of pressure pulsation was observed to be more significant at low flow rate and the flexibility of the outlet silicone catheter was estimated to significantly reduce flow increase due to pressure pulsation.

• The Journal of Korean Medicine
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• v.35 no.1
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• pp.1-9
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• 2014

Objectives: This study was to propose a standardized method of retention enema by extracting elements associated with published experimental methods of retention enema. Methods: 1) Literature search (1) Data sources: Retrieval was made, using 'Enema' or 'Retention Enema' as search words in Medline, Cochrane library, KISS, RISS, and KDSL DB. (2) Study selection: Two authors excluded irrelevant papers and chose qualified abstracts from the rest of the papers. The chosen studies were reviewed fully by the authors so that they could screen the significant papers based on the exclusion criteria. (3) Data extraction: Data on the total number of subjects, the target disease, the animal species, the type, quality, length, and diameter of catheter, the insertion length of catheter, the sample, the sample volume, the process of retention enema and the number of retention enemas performed were extracted from the selected studies. 2) Performing preliminary experiments about the elements associated with experimental methods of retention enema. Results & Conclusions: The standardized experimental method is as follows: animal: 280-320g SD rat 1) inserting a rectal tube of 8 Fr that measures 8 cm into the animal's anus, 2) injecting herbal medicines at the volume of 6ml and 3) holding them for 10 minutes.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.299-304
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• 2022

This study uses the 'S-align' function to present a reference value of the X-ray tube angle for the realization of an image similar to that of the chest PA image during chest AP radiography. This study targeted dummy phantom and used a 17"×17" DR image receptor. The irradiation conditions were 110 kVp, 160 mA, 50 ms, and the distance between the central X-ray and the image receptor was set to 180 cm and 110 cm, respectively. The end of the catheter was placed at the 11th thoracic height to indicate the nasogastric tube. In the case of lung apex length measurement, the mean value of measurement was 30.53±0.47 in PA. T 0°, TCA 5~25°, TCE 5~15° were 21.07±0.29, 27.60±0.21, 34.13±0.44, 39.86±0.31, 45.96±0.61 mm, 54.13±0.37 mm, 16.16±0.46 mm, 9.81±0.35 mm, 2.75±0.30 mm, respectively. For the depth of the catheter end, the average value measured at PA was 6.70±0.31 mm. T 0°, TCA 5~25°, TCE 5~15° were 15.72±0.38 mm, 24.10±0.50 mm, 29.24±0.86 mm, 34.35±0.35 mm, 41.06±1.08 mm, 48.07±0.38 mm, 12.85±0.25 mm, 7.92±0.36 mm, 3.01±0.39 mm, respectively. The length of the lung apex was similar to that of chest PA when the angle of incidence was adjusted from 5° to 10° in the leg direction, and the depth of the catheter tip was most similar when the X-ray tube angle was incident at 10° in the head direction. Therefore, To change the X-ray tube angle according to the purpose of the examination during the chest AP radiography using 'S-align' function is considered necessary.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.4103-4103
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• 2001

The aim of this study was to examine whether near infrared spectroscopy (NIRS) is an acceptable tool to determine cholesterol and collagen in human atherosclerotic plaque without destruction of the analyzed areas and without danger the endothelial cells - three preconditions for the development of a NIR-heart-catheter. The questions were: Can the cholesterol and collagen content of the arterial intima be estimated with acceptable precision in vitro by NIRS despite the matrix inhomogeneity of the plaques and their anatomic variability\ulcorner How deep can such NIR radiation penetrate into arterial tissue without danger for endothelial cells\ulcorner Is this penetration sufficient for information on the lipid and collagen accumulation\ulcorner Using NIRS, cholesterol and collagen can be determined with acceptable precision in model mixtures and human aortic specimens (r=0,896 to 0,957). The chemical reference method was HPLC. The energy dose was 71 mW/$cm^{-2}$ using a fiber optic strand with a length of 1.5m and an optical window of d=4mm. This dose appears to be not dangerous for endothelial cells, It will be attenuated to 50% by a arterial tissue of about 170-$200\mu\textrm{m}$ thickness. The results are also acceptable using a thin coronary catheter-like fiber optic strand (d=1mm).

• Progress in Medical Physics
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• v.28 no.2
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• pp.39-44
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• 2017

This study aims to analyze dose distribution and treatment time of endobronchial brachytherapy (EBBT) by changing the position step size of the dwell position. A solid water phantom and an intraluminal catheter were used in the treatment plan. The treatment plans were generated for 3, 5, 7, and 10 cm treatment lengths, respectively. For each treatment length, the source position step sizes were set as 2.5, 5, and 10 mm. Three reference points were set 1 cm away from the central axis of the catheter, along the axis, for uniform dose distribution. Volumetric dose distribution was calculated to evaluate the dosimetric effect. The total radiation delivery time and total dwell time were estimated for treatment efficiency, which were increased with position step sizes. At half-life time, the differences between the position step sizes in the total radiation delivery time were 18.1, 15.4, 18.0, and 24.0 s for 3, 5, 7, and 10 cm treatment lengths, respectively. The dose distributions were more homogenous by increasing the position step sizes. The dose difference of the reference point was less than 10%. In brachytherapy, this difference can be negligible. For EBBT, the treatment time is the key factor while considering the patient status. To reduce the total treatment time, EBBT can be performed with 2.5 mm position step size.

• Progress in Medical Physics
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• v.10 no.1
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• pp.1-7
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• 1999

In this study, the dose distributions of a $^{32}$ p uniform cylindrical volume source and a surface source, a pure $\beta$emitter, were calculated in order to obtain information relevant to the utilization of a balloon catheter and a radioactive stent. The dose distributions of $^{32}$ p were calculated by means of the EGS4 code system. The sources are considered to be distributed uniformly in the volume and on the surface in the form of a cylinder with a radius of 1.5 mm and length of 20 mm. The energy of $\beta$particles emitted is chosen at random in the $\beta$ energy spectrum evaluated by the solution of the Dirac equation for the Coulomb potential. Liquid water is used to simulate the particle transport in the human body. The dose rates in a target at a 0.5mm radial distance from the surface of cylindrical volume and surface source are 12.133 cGy/s per GBq (0.449 cGy/s per mCi, uncertainty: 1.51%) and 24.732 cGy/s per GBq (0.915 cGy/s per mCi, uncertainty: 1.01%), respectively. The dose rates in the two sources decrease with distance in both radial and axial direction. On the basis of the above results, the determined initial activities were 29.69 mCi and 1.2278 $\mu$Ci for the balloon catheter and the radioactive stent using $^{32}$ P isotope, respectively. The total absorbed dose for optimal therapeutic regimen is considered to be 20 Gy and the treatment time in the case of the balloon catheter is less than 3 min. Absorbed doses in targets placed in a radial direction for the two sources were also calculated when it expressed initial activity in a 1 mCi/ml volume activity density for the cylindrical volume source and a 0.1 mCi/cm$^2$ area activity density for the surface source. The absorbed dose distribution around the $^{32}$ P cylindrical source with different size can be easily calculated using our results when the volume activity density and area activity density for the source are known.

• Journal of Sasang Constitutional Medicine
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• v.25 no.2
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• pp.108-114
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• 2013

Objectives This study was aimed to review a standardized method of retention enema by extracting elements associated with methods of retention enema from papers involved. Methods 1) Data sources : Retrieval was made, using 'Enema' or 'Retention Enema' as search words in MEDLINE, The Cochrane Library, KISS, RISS, and NDSL DB. 2) Study selection : Two authors excluded irrelevant papers and chose qualified abstracts in the rest of the papers. The chosen studies were reviewed fully by the authors so that they could screen the significant papers based on the exclusion criteria. 3) Data extraction : Data on the total number of subjects, the target disease, the type, quality, length, diameter of catheter, the insertion length of catheter, the sample, the sample volume, the process of retention enema and the number of performing retention enema were extracted from the selected studies. Results & Conclusions The retention enema can be applied to gastrointestinal diseases, genitourinary diseases, metabolic diseases such as hypertension and diabetes, headaches and neurological disorders. The standardized treatment method is as following: 1) inserting a rental tube of 18-28 Fr that measures 20 to 30 cm into the patient's anus, 2) injecting herbal medicines which have purgative action or benefit on stomach and intestinal tract at the rate of 4 ml/min, and 3) holding them for 10 to 15 minutes.

• Asian Oncology Nursing
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• v.11 no.1
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• pp.1-8
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• 2011

Purpose: The purpose of this study was to identify the types of venous access devices (VAD) for cancer patients and investigate the factors related to the insertions of central venous catheter (CVC) in cancer patients. Methods: The subjects were 379 cancer patients. A retrospective review of all patients who were discharged from a cancer unit from November 1st to 21st in 2008 was done using a structured questionnaire. Results: A total of 82 CVC (21.6%) was inserted among 379 patients for administering anticancer therapy. There were statistically significant differences in age, length of stay (LOS), cumulative LOS, medical department, history of CVC insertion, cancer category, and albumin level between patients using peripheral intravenous (IV) catheters and CVC. In addition, factors influencing the use of CVC were LOS (odds ratio [OR]=0.286, confidence interval [CI]=1.043-1.124), history of CVC insertion (OR=3.920, CI=0.128-0.637), albumin level (OR=1.010, CI=1.879-8.179), cumulative LOS (OR=1.010, CI=1.001-1.018), and hematological diseases (OR=4.863, CI=2.162-10.925). Conclusion: We found that central venous catheterization for anticancer therapy was minimal even though CVC was safe and effective device for IV access. It is necessary to develop a strategy to use VADs efficiently and timely for cancer patients.

• Archives of Plastic Surgery
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• v.39 no.3
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• pp.253-256
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• 2012

A radial forearm free flap has been conventionally used for urethral reconstruction. However, aesthetic and functional complications occur frequently at the donor site. The use of a superficial circumflex iliac artery perforator (SCIP) flap can resolve these disadvantages. Here, we report our case with a review of literature. A 69-year-old man visited our hospital with multiple contusions of the abdomen and genital amputation. After necrotic tissue debridement, the length of the residual corpus carvernosum was 1.5 cm and that of the corpus spongiosum and urethra was 1 cm. For the reconstruction of the penis, a SCIP flap and anterolateral thigh free flap was performed. The primary closure was performed at the donor site. Three weeks postoperatively, the patient had a urethral foley catheter removed. The neourethra was functioning well without stricture. Four months postoperatively, the patient had no complications such as urethral stricture. A good recovery was also achieved with no aesthetic deficits at the donor site. SCIP flap is appropriate for urethral reconstruction. Because of its proximity to the recipient sites, it makes surgical preparation easier and the primary closure at the donor site available. It is also advantageous in that its location is almost unnoticeable.

• Journal of Chest Surgery
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• v.30 no.8
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• pp.747-751
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• 1997

We developed a subcutaneously adjustable new pulmonary artery banding device which can be easily tightened or released in patients with unstable postoperative hemodynamics. The banding device consists of stainless spring which is enveloped with PTFE, nd polyvinyl catheter(5F). And the adjuster consists of another polyvinyl tube with forming cap. We mark transluscent polyvinyl tube 1mm each in length. 6 dogs weighing 15 to 25 kg underwent banding of descending thoracic aorta with the device. At postoperative 1 and 2 day, the device was effectively banded and released. Even 3 months later, we noted effective banding with some degree of vessel injury. The preliminary animal study suggests that this new device may be applicable in patient with excessive pulmonary blood flow.