• 한국유체기계학회 논문집
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• 제11권1호
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• pp.40-45
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• 2008

This paper proposes a tube pump composed of small-sized cams and followers for an implantable intrathecal drug infusion device. Each followers is driven by a cam and liquid is discharged by a sequential reciprocal motion of the followers. The advantage of this structure is that it allows the pump to be clean and valveless. To design a small-sized, low power pump some analysis were performed to determine the design parameters of the cam, follower and the tube. To verify the feasibility of the experiment, a prototype was manufactured and its operating characteristics were investigated. Experimental results were in accordance with the expected results obtained from analysis.

• 한국유체기계학회 논문집
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• 제12권3호
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• pp.31-37
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• 2009

This paper presents a implantable intrathecal drug infusion pump for pain control in cancer patients. This device consists of micropump module, drug reservoir module and control module. The micropump module using cam-follower mechanism composed of small-sized four cams and four followers. Each followers is driven by a cam and liquid is discharged by a sequential reciprocal motion of the followers. The advantage of this structure is that it allows the pump to be clean and valveless. The drug reservoir module composed of drug chamber, gas chamber and diaphragm. The control module composed of battery, wireless communication unit and controller. To design a small-sized, low power pump some analysis were performed to determine the design parameters. To verify the feasibility of the experiment, a prototype was manufactured and its operating characteristics were investigated. Experimental results were in accordance with the expected results obtained from analysis.

• 대한의용생체공학회:의공학회지
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• 제36권6호
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• pp.291-295
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• 2015

Various types of implantable drug delivery devices have attracted significant attention for several decades to improve drug bioavailability and reduce side effects, thus enhancing therapeutic efficacy and patients' compliance. However, when implanted into the body, the devices may be influenced by the changes in physiological condition, such as temperature, pH or ionic concentration. Thus, the drug release rates could be also altered concurrently. Therefore, in this work, we employed an implantable ALZET$^{(R)}$ Osmotic Pump, which has been widely used to locally deliver various therapeutic agents and examined the effect of pH, temperature and ionic concentration on its drug release rate. For this, we performed in vitro cell tests to simulate the condition of local tissues influenced by the altered drug release rates, where we used diclofenac sodium as a model drug.

• The Korean Journal of Pain
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• 제27권3호
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• pp.297-300
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• 2014

This report describes the long term safety and efficacy of intrathecal therapy using Sufentanil for the management of chronic intractable neuropathic pain in 12 chronic pain patients. Standardized psychological screening was used to determine treatment suitability. Evaluation data included the Visual Analog Scale (VAS), Wong-Baker Faces Scale, Brief Pain Inventory (BPI), Disability of Arm, Shoulder, and Hand (DASH), McGill Quality of Life Questionnaire, and complications (granulomas, toxicity, withdrawal, or deaths). SPSS version 18 was used for data analysis. Pre- and post- treatment BPI measures and pain scale scores showed a statistically significant difference. There were no complications directly related to drug toxicity, nor drug withdrawals, granulomas, or deaths. Intrathecal therapy with Sufentanil therapy offers a good treatment alternative for those cases that have failed both surgery and standard pain treatment. Strict patient selection based on psychological screening, control of co-morbidities, a proper pain management may contribute to successful outcome.

• The Korean Journal of Pain
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• 제25권1호
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• pp.47-51
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• 2012

Intrathecal drug administration system (ITDAS) can reduce the side effects while increasing the effectiveness of opioids compared to systemic opioid administration. Therefore, the use of ITDAS has increased in the management of cancer pain and chronic intractable pain. Catheter obstruction is a serious complication of ITDAS. Here, we present a case of catheter obstruction by a mass formed at the side hole and in the lumen. A 37-year-old man suffering from failed back surgery syndrome received an ITDAS implantation, and the ITDAS was refilled with morphine every 3 months. When the patient visited the hospital 18 months after ITDAS implantation for a refill, the amount of delivered morphine sulfate was much less than expected. Movement of the pump rotor was examined with fluoroscopy; however, it was normal. CSF aspiration through the catheter access port was impossible. When the intrathecal catheter was removed, we observed that the side hole and lumen of the catheter was plugged.

• The Korean Journal of Pain
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• 제22권1호
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• pp.68-73
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• 2009

Opioids profoundly inhibit evoked discharges of spinal nociceptive neurons, thereby inhibiting the transmission of pain. Intrathecal administration of opioids using implantable continuous infusion systems is an effective method of pain relief when other treatments have failed, as well as for patients with adequate analgesia on high dose therapy that produces unacceptable side effects. We report two cases of intrathecal pump implantation performed in patients suffering from intractable chronic pain. A test dose of 3 mg morphine was injected into the epidural space. No side effects were noted and patients experienced considerable pain relief. Implantation was performed one day after the test. The initial intrathecal morphine delivery dose was half of the equivalent dose of daily oral intake opioids and the infusion rate was increased gradually under close observation for opioid side effects. Two days post-implantation, both patients were discharged without any complications.

• The Korean Journal of Pain
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• 제27권2호
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• pp.139-144
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• 2014

Background: To manage intractable cancer pain, an alternative to systemic analgesics is neuraxial analgesia. In long-term treatment, intrathecal administration could provide a more satisfactory pain relief with lower doses of analgesics and fewer side-effects than that of epidural administration. However, implantable drug delivery systems using intrathecal pumps in Korea are very expensive. Considering cost-effectiveness, we performed epidural analgesia as an alternative to intrathecal analgesia. Methods: We retrospectively investigated the efficacy, side effects, and complications of epidural morphine and local anesthetic administration through epidural catheters connected to a subcutaneous injection port in 29 Korean terminal cancer patients. Patient demographic data, the duration of epidural administration, preoperative numerical pain rating scales (NRS), side effects and complications related to the epidural catheterization and the drugs, and the numerical pain rating scales on the 1st, 3rd, 7th and 30th postoperative days were determined from the medical records. Results: The average score for the numerical pain rating scales for the 29 patients decreased from $7{\pm}1.0$ at baseline to $3.6{\pm}1.4$ on postoperative day 1 (P < 0.001). A similar decrease in pain intensity was maintained for 30 days (P < 0.001). Nausea and vomiting were the most frequently reported side effects of the epidural analgesia and two patients (6.9%) experienced paresthesia. Conclusions: Epidural morphine and local anesthetic infusion with a subcutaneous pump seems to have an acceptable risk-benefit ratio and allows a high degree of autonomy to patients with cancer pain.