Hemostasis Plug for an Electromagnetic Thermotherapy and Its Application for Liver Laceration.

Accident-induced liver trauma is a significant human health concern, as this organ is readily injured during periods at which the abdominal region is compromised. In this work, electromagnetic thermotherapy was successfully developed and employed in vitro and in vivo to treat livers that had been lacerated. Briefly, a new hemostasis plug was integrated with an electromagnetic thermotherapy system (ETS) to perform surgery on lacerated livers. The high-frequency, alternating electromagnetic field (EMF) was generated by the ETS and was shown to induce a pre-set temperature increase within the hemostasis plug embedded in the target tissue. In order to prevent overheating and maintain a constant hemostasis temperature, a temperature feedback control system was utilized. The effect of the intensity of the EMF on the heating capacity of the ETS-hemostasis system was first explored. Furthermore, the relationship between the coagulation zone and operating temperature were investigated in vitro. By utilizing the temperature feedback control system, the hemostasis plug could be heated to a specific temperature for efficient hemostasis. With this approach, the optimal treatment temperature and time were investigated for liver laceration. Lacerated livers from New Zealand white rabbits were successfully treated with the hemostasis plug and ETS within a short period of time. When compared with the traditional perihepatic packing approach, the volume of blood loss from liver laceration surgeries treated by ETS has been dramatically reduced by 83%, suggesting a high therapeutic potential for this system.

Electromagnetic thermotherapy for deep organ ablation by using a needle array under a synchronized-coil system.

Thermal ablation by using electromagnetic thermotherapy (EMT) has been a promising cancer modality in recent years. It has relatively few side effects and has therefore been extensively investigated for a variety of medical applications in internal medicine and surgery. The EMT system applies a high-frequency alternating electromagnetic field to heat up the needles which are inserted into the target tumor to cause tumor ablation. In this study, a new synchronized-coil EMT system was demonstrated, which was equipped with two synchronized coils and magnetic field generators to provide a long-range, penetrated electromagnetic field to effectively heat up the needles. The heating effect of the needles at the center of the two coils was first explored. The newly designed two-section needle array combined with the synchronized-coil EMT system was thus demonstrated in the in vitro and in vivo animal experiments. Experimental data showed that the developed system is promising for minimally invasive surgery since it might provide superior performance for thermotherapy in cancer treatment.

An electromagnetic thermotherapy system with a deep penetration depth for percutaneous thermal ablation.

Thermal ablation has been a promising method to remove the cancerous tissues. Electromagnetic-based thermotherapy has been extensively investigated for a variety of medical applications recently. In this study, a prototype electromagnetic thermotherapy system has been developed with a new coil design and a two-section needle. The coil can generate an alternating electromagnetic field (EMF) with a deep penetration depth to remotely heat the needle which is located up to 15 cm away, enabling percutaneous thermal ablation. Several important parameters, including the heating effects of the needle at different positions, the intensity of the EMF and the induced temperature distribution on the surrounding tissue, are first explored. An in vitro animal experiment has also been performed which shows EMF-induced ablation in a porcine liver by the needle. Furthermore, an in vivo experiment on an animal model (a New Zealand white rabbit) is also conducted in the study. Thus, the two-section needle combined with the coil-generated EMF has been demonstrated to be a promising thermotherapy system for percutaneous thermal ablation.

Electromagnetic thermotherapy system with needle arrays: a practical tool for the removal of cancerous tumors.

Thermotherapy has been a promising method to treat tumor. In recent years, electromagnetic thermotherapy (EMT) has been extensively investigated and holds the potential for a variety of medical applications including for cancer treatment when combined with minimally invasive surgery approach. In this study, an alternating electromagnetic frequency was provided by an EMT system to heat up stainless steel needle arrays which were inserted into the target tumor to a high temperature, therefore leading to local ablation of the tumor. A new two-section needle-array apparatus was further demonstrated to encompass the tumor to prevent the tumor cells to spread after the treatment process. By using the needle-array insertion apparatus, there is no limitation of the treatment area; this method could, therefore, be applied for tumors that are larger than 6 cm. It was first successfully demonstrated in the in vitro experiments on porcine livers. Then an in vivo experiment was directly conducted on pigs. The two-section needle array incorporated with the needle-array apparatus and EMT was demonstrated to be promising for no-touch isolation treatment of cancerous tumors.

Successfully seal pancreatic end after thermal distal pancreatectomy using needle arrays in alternating electromagnetic fields.

BACKGROUND: Pancreatic fistula is still the major postoperative morbidity after distal pancreatectomy (DP). An inductive heat technology via needle arrays in a system of alternating magnetic fields (AMFs) was designed to seal off the pancreatic end. METHODS: Twenty Lanyu pigs were divided into 2 groups for DP: the conventional group had hand-sewn closure of the pancreatic end (n = 10), and the AMF group received thermal DP by AMF (n = 10). Pathological examinations of the resected and remnant pancreas were studied immediately after resection and on the 14th postoperative day (POD), respectively. The severity and the incidence of pancreatic abscess were compared. RESULTS: The incidence and severity of pancreatic abscess were significantly decreased in the AMF group than those in the conventional group (P = .009). In the immediate postoperative period, microscopic examination of the pancreatic resected end showed prominent coagulative necrosis, loss of NADPH-diaphorase activity, and significant apoptosis at the resected pancreas in the AMF group compared with the control group. Fourteen days after AMF ablation, the pancreatic stump end was covered with thick fibrosis, and histological study of the remnant pancreas showed that the parenchyma had well recovered with positive NADPH-diaphorase activity, and the pancreatic duct was sealed off successfully by prominent periductal fibrosis and intraductal plug. The body weight gain on the 14th POD was significantly increased in the AMF group (from 23.8 ± 1.8 kg to 25.4 ± 5.5 kg) compared with the conventional group (from 25.3 ± 2.1 to 25.4 ± 6.0 kg; P = .003). CONCLUSIONS: Inductive heats by the AMF system via needle array can be performed easily and can seal the pancreatic cut surface well during DP.

Dual-row needle arrays under an electromagnetic thermotherapy system for bloodless liver resection surgery.

Electromagnetic thermotherapy has been extensively investigated recently and may become a new surgical modality for a variety of medical applications. It applies a high-frequency alternating magnetic field to heat up magnetic materials inserted within the human body to generate tissue coagulation or cell apoptosis. Using a new procedure with dual-row needle arrays under an electromagnetic thermotherapy system with a feedback temperature control system, this study demonstrates bloodless porcine liver resection, which is challenging using existing methods. In vitro experiments showed that hollowed, stainless-steel needles could be heated up to more than 300 °C within 30 s when centered under the induction coils of the electromagnetic thermotherapy system. In order to generate a wide ablation zone and to prevent the dual-row needle arrays from sticking to the tissue after heating, a constant temperature of 120 °C was applied using a specific treatment protocol. The temperature distribution in the porcine livers was also measured to explore the effective coagulation area. Liver resection was then performed in Lan-Yu pigs. Experimental results showed that seven pigs underwent liver resection without bleeding during surgery and no complications afterward. The dual-row needle arrays combined with the electromagnetic thermotherapy system are thus shown to be promising for bloodless tissue resection.

Electromagnetic thermoablation to treat thrombocytopenia in cirrhotic and hypersplenic rats.

BACKGROUND AND AIM: Thrombocytopenia due to hypersplenism is usually a serious condition in cirrhotic patients who have undergone invasive procedures. We designed a new treatment method using a high-frequency alternating electromagnetic force to treat the disease condition in a rat model. METHODS: Sprague-Dawley rats were given thioacetamide in drinking water and injected with methylcellulose intraperitoneally to create a cirrhotic hypersplenism model. Spleen volume was determined using the Carlson method. The Control Group consisted of 14 rats, 15 weeks old, that were used to determine the normal platelet count and normal spleen size. Experimental Group I, consisting of 15 rats, received electromagnetic thermoablation of their spleens, after which the spleen was returned to the abdomen. Group II consisted of 13 rats, receiving the same electromagnetic thermoablation as Group I, but the ablated portion was removed. Group III consisted of 14 rats receiving total splenectomies. RESULTS: Cirrhotic hypersplenism was confirmed during laparotomy and pathological examination. Spleen volume enlarged from 1513 +/- 375 mm(3) (Control Group) to 7943 +/- 2822 mm(3) (experimental groups). Platelet counts increased from 0.35 +/- 0.21 x 10(6)/mm(3) to 0.87 +/- 0.24 x 10(6)/mm(3) for Group I, from 0.52 +/- 0.23 x 10(6)/mm(3) to 1.10 +/- 0.20 x 10(6)/mm(3) for Group II, and from 0.47 +/- 0.23 x 10(6)/mm(3) to 1.18 +/- 0.26 x 10(6)/mm(3) for Group III. No rats died due to the treatment in any of the experimental groups. CONCLUSIONS: Our animal model performed successfully and our proposed electromagnetic thermotherapy effectively treated thrombocytopenia due to cirrhotic hypersplenism.

Microfluidic cell culture systems for drug research.

In pharmaceutical research, an adequate cell-based assay scheme to efficiently screen and to validate potential drug candidates in the initial stage of drug discovery is crucial. In order to better predict the clinical response to drug compounds, a cell culture model that is faithful to in vivo behavior is required. With the recent advances in microfluidic technology, the utilization of a microfluidic-based cell culture has several advantages, making it a promising alternative to the conventional cell culture methods. This review starts with a comprehensive discussion on the general process for drug discovery and development, the role of cell culture in drug research, and the characteristics of the cell culture formats commonly used in current microfluidic-based, cell-culture practices. Due to the significant differences in several physical phenomena between microscale and macroscale devices, microfluidic technology provides unique functionality, which is not previously possible by using traditional techniques. In a subsequent section, the niches for using microfluidic-based cell culture systems for drug research are discussed. Moreover, some critical issues such as cell immobilization, medium pumping or gradient generation in microfluidic-based, cell-culture systems are also reviewed. Finally, some practical applications of microfluidic-based, cell-culture systems in drug research particularly those pertaining to drug toxicity testing and those with a high-throughput capability are highlighted.

A microfluidic chip for formation and collection of emulsion droplets utilizing active pneumatic micro-choppers and micro-switches.

The formation of emulsification droplets is crucial for many industrial applications. This paper reports a new microfluidic chip capable of formation and collection of micro-droplets in liquids for emulsion applications. This microfluidic chip comprising microchannels, a micro-chopper and a micro-switch was fabricated by using micro-electro-mechanical-systems (MEMS) technology. The microfluidic chip can generate uniform droplets with tunable sizes by using combination of flow-focusing and liquid-chopping techniques. The droplet size can be actively fine-tuned by controlling either the relative sheath/sample flow velocity ratios or the chopping frequency. The generated droplets can be then sorted to a specific collection area utilizing an active pneumatic micro-switch formed with three micro-valves. Experimental data showed that the olive oil and sodium-alginate (Na-alginate) droplets with diameters ranging from 3 mum to 70 mum with a variation less than 14% is successfully generated and collected. The development of this microfluidic system can be promising for emulsion, drug delivery and nano-medicine applications.